RPS-BLAST 2.2.26 [Sep-21-2011]

Database: CDD.v3.10 
           44,354 sequences; 10,937,602 total letters

Searching..................................................done

Query= psy5076
         (288 letters)



>gnl|CDD|198180 cd09926, SH2_CRK_like, Src homology 2 domain found in
           cancer-related signaling adaptor protein CRK.  SH2
           domain in the CRK proteins.  CRKI (SH2-SH3) and CRKII
           (SH2-SH3-SH3) are splicing isoforms of the oncoprotein
           CRK.  CRKs regulate transcription and cytoskeletal
           reorganization for cell growth and motility by linking
           tyrosine kinases to small G proteins. The SH2 domain of
           CRK associates with tyrosine-phosphorylated receptors or
           components of focal adhesions, such as p130Cas and
           paxillin. CRK transmits signals to small G proteins
           through effectors that bind its SH3 domain, such as C3G,
           the guanine-nucleotide exchange factor (GEF) for Rap1
           and R-Ras, and DOCK180, the GEF for Rac6. The binding of
           p130Cas to the CRK-C3G complex activates Rap1, leading
           to regulation of cell adhesion, and activates R-Ras,
           leading to JNK-mediated activation of cell
           proliferation, whereas the binding of CRK DOCK180
           induces Rac1-mediated activation of cellular migration.
           The activity of the different splicing isoforms varies
           greatly with CRKI displaying substantial transforming
           activity, CRKII less so, and phosphorylated CRKII with
           no biological activity whatsoever.  CRKII has a linker
           region with a phosphorylated Tyr and an additional
           C-terminal SH3 domain. The phosphorylated Tyr creates a
           binding site for its SH2 domain which disrupts the
           association between CRK and its SH2 target proteins.  In
           general SH2 domains are involved in signal transduction.
            They typically bind pTyr-containing ligands via two
           surface pockets, a pTyr and hydrophobic binding pocket,
           allowing proteins with SH2 domains to localize to
           tyrosine phosphorylated sites.
          Length = 106

 Score =  161 bits (410), Expect = 1e-50
 Identities = 62/105 (59%), Positives = 81/105 (77%), Gaps = 2/105 (1%)

Query: 5   FDPHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIIN 64
           FD  DR+SWYFG M+RQEAQ +L  ++  G FLVRDS+TI G+YVL V EN++VSHYIIN
Sbjct: 1   FDSSDRSSWYFGPMSRQEAQELLQGQRH-GVFLVRDSSTIPGDYVLSVSENSRVSHYIIN 59

Query: 65  KIT-NTEQQTCYKIGDKTFSDLPSLLAFYKVHYLDTSPLIKPATK 108
            +      Q+ Y+IGD+ F DLP+LL FYK+HYLDT+ LI+PA++
Sbjct: 60  SLGQPAPNQSRYRIGDQEFDDLPALLEFYKLHYLDTTTLIEPASR 104


>gnl|CDD|212693 cd11759, SH3_CRK_C, C-terminal Src Homology 3 domain of Ct10
           Regulator of Kinase adaptor proteins.  CRK adaptor
           proteins consists of SH2 and SH3 domains, which bind
           tyrosine-phosphorylated peptides and proline-rich
           motifs, respectively. They function downstream of
           protein tyrosine kinases in many signaling pathways
           started by various extracellular signals, including
           growth and differentiation factors. Cellular CRK (c-CRK)
           contains a single SH2 domain, followed by N-terminal and
           C-terminal SH3 domains. It is involved in the regulation
           of many cellular processes including cell growth,
           motility, adhesion, and apoptosis. CRK has been
           implicated in the malignancy of various human cancers.
           The C-terminal SH3 domain of CRK has not been shown to
           bind any target protein; it acts as a negative regulator
           of CRK function by stabilizing a structure that inhibits
           the access by target proteins to the N-terminal SH3
           domain. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes by intramolecular interactions,
           changing the subcellular localization of signal pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score =  120 bits (303), Expect = 3e-35
 Identities = 45/57 (78%), Positives = 51/57 (89%)

Query: 205 PAFARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEF 261
           PA+ARV Q RVPNAYDKTAL LE+GD++KVTK N++GQWEGELNGK GHFPFTHVE 
Sbjct: 1   PAYARVIQKRVPNAYDKTALALEVGDLVKVTKINVSGQWEGELNGKVGHFPFTHVEL 57


>gnl|CDD|212692 cd11758, SH3_CRK_N, N-terminal Src Homology 3 domain of Ct10
           Regulator of Kinase adaptor proteins.  CRK adaptor
           proteins consists of SH2 and SH3 domains, which bind
           tyrosine-phosphorylated peptides and proline-rich
           motifs, respectively. They function downstream of
           protein tyrosine kinases in many signaling pathways
           started by various extracellular signals, including
           growth and differentiation factors. Cellular CRK (c-CRK)
           contains a single SH2 domain, followed by N-terminal and
           C-terminal SH3 domains. It is involved in the regulation
           of many cellular processes including cell growth,
           motility, adhesion, and apoptosis. CRK has been
           implicated in the malignancy of various human cancers.
           The N-terminal SH3 domain of CRK binds a number of
           target proteins including DOCK180, C3G, SOS, and cABL.
           The CRK family includes two alternatively spliced
           protein forms, CRKI and CRKII, that are expressed by the
           CRK gene, and the CRK-like (CRKL) protein, which is
           expressed by a distinct gene (CRKL). SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score =  104 bits (262), Expect = 5e-29
 Identities = 33/55 (60%), Positives = 40/55 (72%)

Query: 111 EKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           E V A +DF GND +DLPFKK +IL V+ K EE WW A+N  G+ G IPVPYV+K
Sbjct: 1   EYVRALFDFPGNDDEDLPFKKGEILTVIRKPEEQWWNARNSEGKTGMIPVPYVEK 55


>gnl|CDD|215658 pfam00017, SH2, SH2 domain. 
          Length = 77

 Score = 86.5 bits (215), Expect = 8e-22
 Identities = 31/80 (38%), Positives = 48/80 (60%), Gaps = 3/80 (3%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G ++R+EA+ +LL+ K +G FLVR+S +  G+Y L V+++ +V HY I      +  
Sbjct: 1  WYHGKISREEAERLLLNPKPDGTFLVRESESKPGDYTLSVRDDGRVKHYRIQS---LDNG 57

Query: 73 TCYKIGDKTFSDLPSLLAFY 92
            Y  G  TF+ LP L+  Y
Sbjct: 58 GYYISGGVTFNSLPELVEHY 77


>gnl|CDD|214585 smart00252, SH2, Src homology 2 domains.  Src homology 2 domains
          bind phosphotyrosine-containing polypeptides via 2
          surface pockets. Specificity is provided via
          interaction with residues that are distinct from the
          phosphotyrosine. Only a single occurrence of a SH2
          domain has been found in S. cerevisiae.
          Length = 84

 Score = 84.6 bits (210), Expect = 5e-21
 Identities = 34/85 (40%), Positives = 48/85 (56%), Gaps = 4/85 (4%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G ++R+EA+ +L +E D G FLVRDS +  G+YVL V+   KV HY I +    E  
Sbjct: 3  WYHGFISREEAEKLLKNEGD-GDFLVRDSESSPGDYVLSVRVKGKVKHYRIRR---NEDG 58

Query: 73 TCYKIGDKTFSDLPSLLAFYKVHYL 97
            Y  G + F  L  L+  Y+ + L
Sbjct: 59 KFYLEGGRKFPSLVELVEHYQKNSL 83


>gnl|CDD|198173 cd00173, SH2, Src homology 2 (SH2) domain.  In general, SH2
          domains are involved in signal transduction; they bind
          pTyr-containing polypeptide ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites. They are present in a
          wide array of proteins including: adaptor proteins
          (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1),
          kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1,
          Shp-2), transcription factors (STAT1),  Ras signaling
          molecules (Ras-Gap), ubiquitination factors (c-Cbl),
          cytoskeleton regulators (Tensin), signal regulators
          (SAP), and phospholipid second messengers (PLCgamma),
          amongst others.
          Length = 79

 Score = 84.4 bits (209), Expect = 6e-21
 Identities = 30/82 (36%), Positives = 47/82 (57%), Gaps = 4/82 (4%)

Query: 12 SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK-ENNKVSHYIINKITNTE 70
           W+ G ++R+EA+ +L  + D G FLVR+S++  G+YVL V+  + KV HY+I +  N  
Sbjct: 1  PWFHGSISREEAERLLRGKPD-GTFLVRESSSEPGDYVLSVRSGDGKVKHYLIER--NEG 57

Query: 71 QQTCYKIGDKTFSDLPSLLAFY 92
                   +TF  LP L+  Y
Sbjct: 58 GYYLLGGSGRTFPSLPELVEHY 79


>gnl|CDD|214620 smart00326, SH3, Src homology 3 domains.  Src homology 3 (SH3)
           domains bind to target proteins through sequences
           containing proline and hydrophobic amino acids.
           Pro-containing polypeptides may bind to SH3 domains in 2
           different binding orientations.
          Length = 56

 Score = 80.3 bits (199), Expect = 9e-20
 Identities = 22/55 (40%), Positives = 32/55 (58%)

Query: 110 IEKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
             +V A YD+   DPD+L FKK DI+ V+ K ++ WW  +   G+ G  P  YV+
Sbjct: 2   GPQVRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGRGKEGLFPSNYVE 56



 Score = 43.3 bits (103), Expect = 3e-06
 Identities = 19/45 (42%), Positives = 25/45 (55%), Gaps = 1/45 (2%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELN-GKTGHFPFTHVE 260
            A D   L  + GDII V + + +G W+G L  GK G FP  +VE
Sbjct: 12  TAQDPDELSFKKGDIITVLEKSDDGWWKGRLGRGKEGLFPSNYVE 56


>gnl|CDD|215659 pfam00018, SH3_1, SH3 domain.  SH3 (Src homology 3) domains are
           often indicative of a protein involved in signal
           transduction related to cytoskeletal organisation. First
           described in the Src cytoplasmic tyrosine kinase. The
           structure is a partly opened beta barrel.
          Length = 47

 Score = 73.0 bits (180), Expect = 4e-17
 Identities = 20/47 (42%), Positives = 30/47 (63%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPV 160
           +A YD+   +PD+L FKK DI+IV+ K ++ WW  +   G+ G IP 
Sbjct: 1   VALYDYTAREPDELSFKKGDIIIVLEKSDDGWWKGRLKGGKEGLIPS 47



 Score = 29.5 bits (67), Expect = 0.22
 Identities = 18/43 (41%), Positives = 23/43 (53%), Gaps = 6/43 (13%)

Query: 219 YDKTA-----LKLEIGDIIKVTKTNINGQWEGEL-NGKTGHFP 255
           YD TA     L  + GDII V + + +G W+G L  GK G  P
Sbjct: 4   YDYTAREPDELSFKKGDIIIVLEKSDDGWWKGRLKGGKEGLIP 46


>gnl|CDD|212690 cd00174, SH3, Src Homology 3 domain superfamily.  Src Homology 3
           (SH3) domains are protein interaction domains that bind
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. Thus, they
           are referred to as proline-recognition domains (PRDs).
           SH3 domains are less selective and show more diverse
           specificity compared to other PRDs. They have been shown
           to bind peptide sequences that lack the PxxP motif;
           examples include the PxxDY motif of Eps8 and the
           RKxxYxxY sequence in SKAP55. SH3 domain containing
           proteins play versatile and diverse roles in the cell,
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies, among others. Many members of this
           superfamily are adaptor proteins that associate with a
           number of protein partners, facilitating complex
           formation and signal transduction.
          Length = 51

 Score = 71.7 bits (177), Expect = 1e-16
 Identities = 20/51 (39%), Positives = 28/51 (54%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPY 162
              A YD++  D D+L FKK DI+ V+ KD++ WW  +   G  G  P  Y
Sbjct: 1   YARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNGGREGLFPANY 51



 Score = 40.9 bits (97), Expect = 2e-05
 Identities = 17/36 (47%), Positives = 23/36 (63%), Gaps = 1/36 (2%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELN-GKTGHFPFTH 258
           L  + GDII V + + +G WEGELN G+ G FP  +
Sbjct: 16  LSFKKGDIITVLEKDDDGWWEGELNGGREGLFPANY 51


>gnl|CDD|212703 cd11769, SH3_CSK, Src Homology 3 domain of C-terminal Src kinase.
           CSK is a cytoplasmic (or nonreceptor) tyr kinase
           containing the Src homology domains, SH3 and SH2,
           N-terminal to the catalytic tyr kinase domain. They
           negatively regulate the activity of Src kinases that are
           anchored to the plasma membrane. To inhibit Src kinases,
           CSK is translocated to the membrane via binding to
           specific transmembrane proteins, G-proteins, or adaptor
           proteins near the membrane. CSK catalyzes the tyr
           phosphorylation of the regulatory C-terminal tail of Src
           kinases, resulting in their inactivation. It is
           expressed in a wide variety of tissues and plays a role,
           as a regulator of Src, in cell proliferation, survival,
           and differentiation, and consequently, in cancer
           development and progression. In addition, CSK also shows
           Src-independent functions. It is a critical component in
           G-protein signaling, and plays a role in cytoskeletal
           reorganization and cell migration. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 57

 Score = 71.2 bits (175), Expect = 3e-16
 Identities = 29/56 (51%), Positives = 38/56 (67%), Gaps = 3/56 (5%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVV--SKDEEHWWTAQNISGEVGSIPVPYVQK 165
           + IAKY+F+G   +DLPFKK DIL +V  +KD  +W+ A+N  G  G IP  YVQK
Sbjct: 3   ECIAKYNFNGASEEDLPFKKGDILTIVAVTKD-PNWYKAKNKDGREGMIPANYVQK 57


>gnl|CDD|212702 cd11768, SH3_Tec_like, Src Homology 3 domain of Tec-like Protein
           Tyrosine Kinases.  The Tec (Tyrosine kinase expressed in
           hepatocellular carcinoma) subfamily is composed of Tec,
           Btk, Bmx (Etk), Itk (Tsk, Emt), Rlk (Txk), and similar
           proteins. They are cytoplasmic (or nonreceptor) tyr
           kinases containing Src homology protein interaction
           domains (SH3, SH2) N-terminal to the catalytic tyr
           kinase domain. Most Tec subfamily members (except Rlk)
           also contain an N-terminal pleckstrin homology (PH)
           domain, which binds the products of PI3K and allows
           membrane recruitment and activation. In addition, some
           members contain the Tec homology (TH) domain, which
           contains proline-rich and zinc-binding regions. Tec
           kinases are expressed mainly by haematopoietic cells,
           although Tec and Bmx are also found in endothelial
           cells. B-cells express Btk and Tec, while T-cells
           express Itk, Txk, and Tec. Collectively, Tec kinases are
           expressed in a variety of myeloid cells such as mast
           cells, platelets, macrophages, and dendritic cells. Each
           Tec kinase shows a distinct cell-type pattern of
           expression. The function of Tec kinases in lymphoid
           cells have been studied extensively. They play important
           roles in the development, differentiation, maturation,
           regulation, survival, and function of B-cells and
           T-cells. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 70.0 bits (172), Expect = 6e-16
 Identities = 22/54 (40%), Positives = 32/54 (59%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
            V+A YDF   +P DLP +K +  +V+    EHWW A++ +G  G IP  YV +
Sbjct: 1   IVVALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRARDKNGNEGYIPSNYVTE 54


>gnl|CDD|198200 cd10337, SH2_BCAR3, Src homology 2 (SH2) domain in the Breast
          Cancer Anti-estrogen Resistance protein 3.  BCAR3 is
          part of a growing family of guanine nucleotide exchange
          factors is responsible for activation of Ras-family
          GTPases, including Sos1 and 2, GRF1 and 2,
          CalDAG-GEF/GRP1-4, C3G, cAMP-GEF/Epac 1 and 2,
          PDZ-GEFs, MR-GEF, RalGDS family members, RalGPS,
          RasGEF, Smg GDS, and phospholipase C(epsilon). 12102558
           21262352  BCAR3 binds to the carboxy-terminus of
          BCAR1/p130Cas, a focal adhesion adapter protein.  Over
          expression of BCAR1 (p130Cas) and BCAR3 induces
          estrogen independent growth in normally
          estrogen-dependent cell lines. They have been linked to
          resistance to anti-estrogens in breast cancer, Rac
          activation, and cell motility, though the BCAR3/p130Cas
          complex is not required for this activity in BCAR3.
          Many BCAR3-mediated signaling events in epithelial and
          mesenchymal cells are independent of p130Cas
          association. Structurally these proteins contain a
          single SH2 domain upstream of their RasGEF domain,
          which is responsible for the ability of BCAR3 to
          enhance p130Cas over-expression-induced migration. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 136

 Score = 68.9 bits (169), Expect = 1e-14
 Identities = 28/84 (33%), Positives = 46/84 (54%), Gaps = 7/84 (8%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G + RQ A++++  E D   FLVRDS +  G+YVL  +   +  H+ IN++     +
Sbjct: 8  WYHGRIPRQVAESLVQREGD---FLVRDSLSSPGDYVLTCRWKGQPLHFKINRVVLRPSE 64

Query: 73 TC----YKIGDKTFSDLPSLLAFY 92
                Y+  D+ F  +P+L+ FY
Sbjct: 65 AYTRVQYQFEDEQFDSIPALVHFY 88


>gnl|CDD|198223 cd10360, SH2_Srm, Src homology 2 (SH2) domain found in
          Src-related kinase lacking C-terminal regulatory
          tyrosine and N-terminal myristoylation sites (srm).
          Srm is a nonreceptor protein kinase that has two SH2
          domains, a SH3 domain, and a kinase domain with a
          tyrosine residue for autophosphorylation.  However it
          lacks an N-terminal glycine for myristoylation and a
          C-terminal tyrosine which suppresses kinase activity
          when phosphorylated.  Srm is most similar to members of
          the Tec family who other members include: Tec, Btk/Emb,
          and Itk/Tsk/Emt. However Srm differs in its N-terminal
          unique domain it being much smaller than in the Tec
          family and is closer to Src. Srm is thought to be a new
          family of nonreceptor tyrosine kinases that may be
          redundant in function. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 79

 Score = 65.4 bits (159), Expect = 7e-14
 Identities = 32/81 (39%), Positives = 44/81 (54%), Gaps = 4/81 (4%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          WYF  ++R +AQ +LLS  +  GAFL+R S + LG Y L V+   KV HY   +I     
Sbjct: 2  WYFSGISRTQAQQLLLSPPNEPGAFLIRPSESSLGGYSLSVRAQAKVCHY---RICMAPS 58

Query: 72 QTCYKIGDKTFSDLPSLLAFY 92
           + Y    + F  L  LLA+Y
Sbjct: 59 GSLYLQKGRLFPGLEELLAYY 79


>gnl|CDD|198210 cd10347, SH2_Nterm_shark_like, N-terminal Src homology 2 (SH2)
          domain found in SH2 domains, ANK, and kinase domain
          (shark) proteins.  These non-receptor protein-tyrosine
          kinases contain two SH2 domains, five ankyrin
          (ANK)-like repeats, and a potential tyrosine
          phosphorylation site in the carboxyl-terminal tail
          which resembles the phosphorylation site in members of
          the src family. Like, mammalian non-receptor
          protein-tyrosine kinases, ZAP-70 and syk proteins, they
          do not have SH3 domains. However, the presence of ANK
          makes these unique among protein-tyrosine kinases. Both
          tyrosine kinases and ANK repeats have been shown to
          transduce developmental signals, and SH2 domains are
          known to participate intimately in tyrosine kinase
          signaling. These tyrosine kinases are believed to be
          involved in epithelial cell polarity. The members of
          this family include the shark (SH2 domains, ANK, and
          kinase domain) gene in Drosophila and yellow fever
          mosquitos, as well as the hydra protein HTK16.
          Drosophila Shark is proposed to transduce
          intracellularly the Crumbs, a protein necessary for
          proper organization of ectodermal epithelia,
          intercellular signal. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 81

 Score = 64.7 bits (158), Expect = 1e-13
 Identities = 28/82 (34%), Positives = 43/82 (52%), Gaps = 3/82 (3%)

Query: 12 SWYFGMMTRQEAQAILL-SEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
           WY G ++R+ A+A+LL     +G FLVR+S +  G+YVL +    +V HY I +  + E
Sbjct: 2  RWYHGKISREVAEALLLREGGRDGLFLVRESTSAPGDYVLSLLAQGEVLHYQIRR--HGE 59

Query: 71 QQTCYKIGDKTFSDLPSLLAFY 92
                 G   F  L +L+  Y
Sbjct: 60 DAFFSDDGPLIFHGLDTLIEHY 81


>gnl|CDD|199827 cd09933, SH2_Src_family, Src homology 2 (SH2) domain found in the
          Src family of non-receptor tyrosine kinases.  The Src
          family kinases are nonreceptor tyrosine kinases that
          have been implicated in pathways regulating
          proliferation, angiogenesis, invasion and metastasis,
          and bone metabolism. It is thought that transforming
          ability of Src is linked to its ability to activate key
          signaling molecules in these pathways, rather than
          through direct activity. As such blocking Src
          activation has been a target for drug companies. Src
          family members can be divided into 3 groups based on
          their expression pattern: 1) Src, Fyn, and Yes; 2)
          Blk, Fgr, Hck, Lck, and Lyn; and 3) Frk-related kinases
          Frk/Rak and Iyk/Bsk Of these, cellular c-Src is the
          best studied and most frequently implicated in
          oncogenesis. The c-Src contains five distinct regions:
          a unique N-terminal domain, an SH3 domain, an SH2
          domain, a kinase domain and a regulatory tail, as do
          the other members of the family. Src exists in both
          active and inactive conformations. Negative regulation
          occurs through phosphorylation of Tyr, resulting in an
          intramolecular association between phosphorylated Tyr
          and the SH2 domain of SRC, which locks the protein in a
          closed conformation. Further stabilization of the
          inactive state occurs through interactions between the
          SH3 domain and a proline-rich stretch of residues
          within the kinase domain. Conversely, dephosphorylation
          of Tyr allows SRC to assume an open conformation. Full
          activity requires additional autophosphorylation of a
          Tyr residue within the catalytic domain. Loss of the
          negative-regulatory C-terminal segment has been shown
          to result in increased activity and transforming
          potential. Phosphorylation of the C-terminal Tyr
          residue by C-terminal Src kinase (Csk) and Csk homology
          kinase results in increased intramolecular interactions
          and consequent Src inactivation. Specific phosphatases,
          protein tyrosine phosphatase a (PTPa) and the
          SH-containing phosphatases SHP1/SHP2, have also been
          shown to take a part in Src activation. Src is also
          activated by direct binding of focal adhesion kinase
          (Fak) and Crk-associated substrate (Cas) to the SH2
          domain. SRC activity can also be regulated by numerous
          receptor tyrosine kinases (RTKs), such as Her2,
          epidermal growth factor receptor (EGFR), fibroblast
          growth factor receptor, platelet-derived growth factor
          receptor (PDGFR), and vascular endothelial growth
          factor receptor (VEGFR). In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 101

 Score = 64.5 bits (158), Expect = 2e-13
 Identities = 27/89 (30%), Positives = 43/89 (48%), Gaps = 9/89 (10%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKENNK-----VSHYIINKI 66
          W+FG + R++A+ +LL+  +  G FL+R+S T  G Y L V++ +      V HY   +I
Sbjct: 5  WFFGKIKRKDAEKLLLAPGNPRGTFLIRESETTPGAYSLSVRDGDDARGDTVKHY---RI 61

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
             +    Y     TF  L  L+  Y   
Sbjct: 62 RKLDNGGYYITTRATFPTLQELVQHYSKD 90


>gnl|CDD|219499 pfam07653, SH3_2, Variant SH3 domain.  SH3 (Src homology 3) domains
           are often indicative of a protein involved in signal
           transduction related to cytoskeletal organisation. First
           described in the Src cytoplasmic tyrosine kinase. The
           structure is a partly opened beta barrel.
          Length = 53

 Score = 61.3 bits (150), Expect = 8e-13
 Identities = 19/44 (43%), Positives = 26/44 (59%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
            A D   L L+ GD++KV   + NG WEGE  G+ G  P ++VE
Sbjct: 9   VATDPNELSLKKGDVVKVLDKDDNGWWEGERGGRRGLVPSSYVE 52



 Score = 42.8 bits (102), Expect = 4e-06
 Identities = 17/54 (31%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
                +D+   DP++L  KK D++ V+ KD+  WW  +   G  G +P  YV++
Sbjct: 1   YGRVIFDYVATDPNELSLKKGDVVKVLDKDDNGWWEGER-GGRRGLVPSSYVEE 53


>gnl|CDD|199828 cd09941, SH2_Grb2_like, Src homology 2 domain found in Growth
           factor receptor-bound protein 2 (Grb2) and similar
           proteins.  The adaptor proteins here include homologs
           Grb2 in humans, Sex muscle abnormal protein 5 (Sem-5) in
           Caenorhabditis elegans, and Downstream of receptor
           kinase (drk) in Drosophila melanogaster. They are
           composed of one SH2 and two SH3 domains. Grb2/Sem-5/drk
           regulates the Ras pathway by linking the tyrosine
           kinases to the Ras guanine nucleotide releasing protein
           Sos, which converts Ras to the active GTP-bound state.
           The SH2 domain of Grb2/Sem-5/drk binds class II
           phosphotyrosyl peptides while its SH3 domain binds to
           Sos and Sos-derived, proline-rich peptides. Besides it
           function in Ras signaling, Grb2 is also thought to play
           a role in apoptosis. Unlike most SH2 structures in which
           the peptide binds in an extended conformation (such that
           the +3 peptide residue occupies a hydrophobic pocket in
           the protein, conferring a modest degree of selectivity),
           Grb2 forms several hydrogen bonds via main chain atoms
           with the side chain of +2 Asn. In general SH2 domains
           are involved in signal transduction. They typically bind
           pTyr-containing ligands via two surface pockets, a pTyr
           and hydrophobic binding pocket, allowing proteins with
           SH2 domains to localize to tyrosine phosphorylated
           sites.
          Length = 95

 Score = 62.3 bits (152), Expect = 1e-12
 Identities = 25/97 (25%), Positives = 52/97 (53%), Gaps = 4/97 (4%)

Query: 11  NSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
           + W+ G ++R EA+ IL++++ +GAFL+R+S +  G++ L VK  N V H+ + +    +
Sbjct: 3   HPWFHGKISRAEAEEILMNQRPDGAFLIRESESSPGDFSLSVKFGNDVQHFKVLR----D 58

Query: 71  QQTCYKIGDKTFSDLPSLLAFYKVHYLDTSPLIKPAT 107
               Y +    F+ L  L+ +++   +  +  I    
Sbjct: 59  GAGKYFLWVVKFNSLNELVDYHRTTSVSRNQQIFLRD 95


>gnl|CDD|198185 cd09931, SH2_C-SH2_SHP_like, C-terminal Src homology 2 (C-SH2)
          domain found in SH2 domain Phosphatases (SHP) proteins.
           The SH2 domain phosphatases (SHP-1, SHP-2/Syp,
          Drosophila corkscrew (csw), and Caenorhabditis elegans
          Protein Tyrosine Phosphatase (Ptp-2)) are cytoplasmic
          signaling enzymes. They are both targeted and regulated
          by interactions of their SH2 domains with
          phosphotyrosine docking sites. These proteins contain
          two SH2 domains (N-SH2, C-SH2) followed by a tyrosine
          phosphatase (PTP) domain, and a C-terminal extension.
          Shp1 and Shp2 have two tyrosyl phosphorylation sites in
          their C-tails, which are phosphorylated differentially
          by receptor and nonreceptor PTKs. Csw retains the
          proximal tyrosine and Ptp-2 lacks both sites.
          Shp-binding proteins include receptors, scaffolding
          adapters, and inhibitory receptors. Some of these bind
          both Shp1 and Shp2 while others bind only one. Most
          proteins that bind a Shp SH2 domain contain one or more
          immuno-receptor tyrosine-based inhibitory motifs
          (ITIMs): [SIVL]xpYxx[IVL].  Shp1 N-SH2 domain blocks
          the catalytic domain and keeps the enzyme in the
          inactive conformation, and is thus believed to regulate
          the phosphatase activity of SHP-1. Its C-SH2 domain is
          thought to be involved in searching for phosphotyrosine
          activators.  The SHP2 N-SH2 domain is a conformational
          switch; it either binds and inhibits the phosphatase,
          or it binds phosphoproteins and activates the enzyme.
          The C-SH2 domain contributes binding energy and
          specificity, but it does not have a direct role in
          activation. Csw SH2 domain function is essential, but
          either SH2 domain can fulfill this requirement. The
          role of the csw SH2 domains during Sevenless receptor
          tyrosine kinase (SEV) signaling is to bind Daughter of
          Sevenless rather than activated SEV. Ptp-2 acts in
          oocytes downstream of sheath/oocyte gap junctions to
          promote major sperm protein (MSP)-induced MAP Kinase
          (MPK-1) phosphorylation. Ptp-2 functions in the oocyte
          cytoplasm, not at the cell surface to inhibit multiple
          RasGAPs, resulting in sustained Ras activation. It is
          thought that MSP triggers PTP-2/Ras activation and ROS
          production to stimulate MPK-1 activity essential for
          oocyte maturation and that secreted MSP domains and
          Cu/Zn superoxide dismutases function antagonistically
          to control ROS and MAPK signaling. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 99

 Score = 61.9 bits (151), Expect = 2e-12
 Identities = 27/83 (32%), Positives = 48/83 (57%), Gaps = 7/83 (8%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENN-KVSHYIINKITNTEQ 71
          W+ G ++ +EA+ +LL +   G+FLVR+S +  G++VL V+ ++ KV+H +I       +
Sbjct: 2  WFHGHLSGKEAEKLLLEKGKPGSFLVRESQSKPGDFVLSVRTDDDKVTHIMIR--CQGGK 59

Query: 72 QTCYKIGD-KTFSDLPSLLAFYK 93
             Y +G  + F  L  L+  YK
Sbjct: 60 ---YDVGGGEEFDSLTDLVEHYK 79


>gnl|CDD|212704 cd11770, SH3_Nephrocystin, Src Homology 3 domain of Nephrocystin
           (or Nephrocystin-1).  Nephrocystin contains an SH3
           domain involved in signaling pathways that regulate cell
           adhesion and cytoskeletal organization. It is a protein
           that in humans is associated with juvenile
           nephronophthisis, an inherited kidney disease
           characterized by renal fibrosis that lead to chronic
           renal failure in children. It is localized in cell-cell
           junctions in renal duct cells, and is known to interact
           with Ack1, an activated Cdc42-associated kinase. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 60.0 bits (146), Expect = 3e-12
 Identities = 19/53 (35%), Positives = 28/53 (52%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
             A  DF      DL FKK ++L ++SK  + WW A+N  G  G +P  Y++ 
Sbjct: 2   YEALSDFQAEQEGDLSFKKGEVLRIISKRADGWWLAENSKGNRGLVPKTYLKV 54


>gnl|CDD|198196 cd09943, SH2_Nck_family, Src homology 2 (SH2) domain found in the
           Nck family.  Nck proteins are adaptors that modulate
           actin cytoskeleton dynamics by linking proline-rich
           effector molecules to tyrosine kinases or phosphorylated
           signaling intermediates. There are two members known in
           this family: Nck1 (Nckalpha) and Nck2 (Nckbeta and
           Growth factor receptor-bound protein 4 (Grb4)).  They
           are characterized by having 3 SH3 domains and a
           C-terminal SH2 domain. Nck1 and Nck2 have overlapping
           functions as determined by gene knockouts. Both bind
           receptor tyrosine kinases and other
           tyrosine-phosphorylated proteins through their SH2
           domains. In addition they also bind distinct targets.
           Neuronal signaling proteins: EphrinB1, EphrinB2, and
           Disabled-1 (Dab-1) all bind to Nck-2 exclusively. And in
           the case of PDGFR, Tyr(P)751 binds to  Nck1 while
           Tyr(P)1009 binds to Nck2. Nck1 and Nck2 have a role in
           the infection process of enteropathogenic Escherichia
           coli (EPEC). Their SH3 domains are involved in
           recruiting and activating the N-WASP/Arp2/3 complex
           inducing actin polymerization resulting in the
           production of pedestals, dynamic bacteria-presenting
           protrusions of the plasma membrane. A similar thing
           occurs in the vaccinia virus where motile plasma
           membrane projections are formed beneath the virus.
           Recently it has been shown that the SH2 domains of both
           Nck1 and Nck2 bind the G-protein coupled receptor
           kinase-interacting protein 1 (GIT1) in a
           phosphorylation-dependent manner. In general SH2 domains
           are involved in signal transduction. They typically bind
           pTyr-containing ligands via two surface pockets, a pTyr
           and hydrophobic binding pocket, allowing proteins with
           SH2 domains to localize to tyrosine phosphorylated
           sites.
          Length = 93

 Score = 61.4 bits (149), Expect = 3e-12
 Identities = 27/91 (29%), Positives = 44/91 (48%), Gaps = 5/91 (5%)

Query: 11  NSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
             WY+G +TR +A+ +L      G FL+RDS +  G+Y + +K   +  H+   K+    
Sbjct: 1   QPWYYGRITRHQAETLLNEHGHEGDFLIRDSESNPGDYSVSLKAPGRNKHF---KVQV-- 55

Query: 71  QQTCYKIGDKTFSDLPSLLAFYKVHYLDTSP 101
               Y IG + F  +  L+  YK   + TS 
Sbjct: 56  VDNVYCIGQRKFHTMDELVEHYKKAPIFTSE 86


>gnl|CDD|212701 cd11767, SH3_Nck_3, Third Src Homology 3 domain of Nck adaptor
           proteins.  This group contains the third SH3 domain of
           Nck, the first SH3 domain of Caenorhabditis elegans
           Ced-2 (Cell death abnormality protein 2), and similar
           domains. Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4), which show partly
           overlapping functions but also bind distinct targets.
           Their SH3 domains are involved in recruiting downstream
           effector molecules, such as the N-WASP/Arp2/3 complex,
           which when activated induces actin polymerization that
           results in the production of pedestals, or protrusions
           of the plasma membrane. The third SH3 domain of Nck
           appears to prefer ligands with a PxAPxR motif. SH3
           domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially a PxxP motif. Ced-2 is a
           cell corpse engulfment protein that interacts with Ced-5
           in a pathway that regulates the activation of Ced-10, a
           Rac small GTPase.
          Length = 56

 Score = 59.2 bits (144), Expect = 7e-12
 Identities = 20/55 (36%), Positives = 32/55 (58%), Gaps = 2/55 (3%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSK--DEEHWWTAQNISGEVGSIPVPYVQ 164
            V+A Y F G + ++L F+K + L ++ K  D+  WW A+N  G  G +P  YV+
Sbjct: 1   VVVALYPFTGENDEELSFEKGERLEIIEKPEDDPDWWKARNALGTTGLVPRNYVE 55


>gnl|CDD|198190 cd09937, SH2_csk_like, Src homology 2 (SH2) domain found in
          Carboxyl-Terminal Src Kinase (Csk).  Both the
          C-terminal Src kinase (CSK) and CSK-homologous kinase
          (CHK) are members of the CSK-family of protein tyrosine
          kinases. These proteins suppress activity of Src-family
          kinases (SFK) by selectively phosphorylating the
          conserved C-terminal tail regulatory tyrosine by a
          similar mechanism. CHK is also capable of inhibiting
          SFKs by a non-catalytic mechanism that involves binding
          of CHK to SFKs to form stable protein complexes. The
          unphosphorylated form of SFKs is inhibited by CSK and
          CHK by a two-step mechanism. The first step involves
          the formation of a complex of SFKs with CSK/CHK with
          the SFKs in the complex are inactive. The second step,
          involves the phosphorylation of the C-terminal tail
          tyrosine of SFKs, which then dissociates and adopt an
          inactive conformation. The structural basis of how the
          phosphorylated SFKs dissociate from CSK/CHK to adopt
          the inactive conformation is not known. The inactive
          conformation of SFKs is stabilized by two
          intramolecular inhibitory interactions: (a) the pYT:SH2
          interaction in which the phosphorylated C-terminal tail
          tyrosine (YT) binds to the SH2 domain, and (b) the
          linker:SH3 interaction of which the SH2-kinase domain
          linker binds to the SH3 domain. SFKs are activated by
          multiple mechanisms including binding of the ligands to
          the SH2 and SH3 domains to displace the two inhibitory
          intramolecular interactions, autophosphorylation, and
          dephosphorylation of YT. By selective phosphorylation
          and the non-catalytic inhibitory mechanism CSK and CHK
          are able to inhibit the active forms of SFKs. CSK and
          CHK are regulated by phosphorylation and inter-domain
          interactions. They both contain SH3, SH2, and kinase
          domains separated by the SH3-SH2 connector and SH2
          kinase linker, intervening segments separating the
          three domains. They lack a conserved tyrosine
          phosphorylation site in the kinase domain and the
          C-terminal tail regulatory tyrosine phosphorylation
          site. The CSK SH2 domain is crucial for stabilizing the
          kinase domain in the active conformation. A disulfide
          bond here regulates CSK kinase activity. The
          subcellular localization and activity of CSK are
          regulated by its SH2 domain. In general SH2 domains are
          involved in signal transduction.  They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 98

 Score = 60.4 bits (147), Expect = 7e-12
 Identities = 29/85 (34%), Positives = 44/85 (51%), Gaps = 13/85 (15%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYII----NKITN 68
          W+ G ++R+EA+  LL   ++G FLVR+S    G+Y LCV    KV HY +     K+T 
Sbjct: 5  WFHGKISREEAER-LLQPPEDGLFLVRESTNYPGDYTLCVSFEGKVEHYRVIYRNGKLTI 63

Query: 69 TEQQTCYKIGDKTFSDLPSLLAFYK 93
           E++         F +L  L+  Y 
Sbjct: 64 DEEE--------YFENLIQLVEHYT 80


>gnl|CDD|198217 cd10354, SH2_Cterm_RasGAP, C-terminal Src homology 2 (SH2) domain
          found in Ras GTPase-activating protein 1 (GAP).  RasGAP
          is part of the GAP1 family of GTPase-activating
          proteins. The protein is located in the cytoplasm and
          stimulates the GTPase activity of normal RAS p21, but
          not its oncogenic counterpart. Acting as a suppressor
          of RAS function, the protein enhances the weak
          intrinsic GTPase activity of RAS proteins resulting in
          RAS inactivation, thereby allowing control of cellular
          proliferation and differentiation. Mutations leading to
          changes in the binding sites of either protein are
          associated with basal cell carcinomas. Alternative
          splicing results in two isoforms. The shorter isoform
          which lacks the N-terminal hydrophobic region, has the
          same activity, and is expressed in placental tissues.
          In general longer isoform contains 2 SH2 domains, a SH3
          domain, a pleckstrin homology (PH) domain, and a
          calcium-dependent phospholipid-binding C2 domain. The
          C-terminus contains the catalytic domain of RasGap
          which catalyzes the activation of Ras by hydrolyzing
          GTP-bound active Ras into an inactive GDP-bound form of
          Ras. This model contains the C-terminal SH2 domain. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 77

 Score = 58.2 bits (141), Expect = 3e-11
 Identities = 25/80 (31%), Positives = 43/80 (53%), Gaps = 4/80 (5%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          W+ G ++R+EA  +L+     G+FLVR+S+   G+Y L  + N  + H+   KI  T   
Sbjct: 2  WFHGKISREEAYNMLVKVGGPGSFLVRESDNTPGDYSLSFRVNEGIKHF---KIIPTGNN 58

Query: 73 TCYKIGDKTFSDLPSLLAFY 92
            + +G + FS L  ++  Y
Sbjct: 59 Q-FMMGGRYFSSLDDVIDRY 77


>gnl|CDD|198233 cd10370, SH2_Src_Src42, Src homology 2 (SH2) domain found in the
          Src oncogene at 42A (Src42).  Src42 is a member of the
          Src non-receptor type tyrosine kinase family of
          proteins. The integration of receptor tyrosine
          kinase-induced RAS and Src42 signals by Connector
          eNhancer of KSR (CNK) as a two-component input is
          essential for RAF activation in Drosophila. Src42 is
          present in a wide variety of organisms including:
          California sea hare, pea aphid, yellow fever mosquito,
          honey bee, Panamanian leafcutter ant, and sea urchin.
          Src42 has a unique N-terminal domain, an SH3 domain, an
          SH2 domain, a kinase domain and a regulatory tail, as
          do the other members of the family. Like the other
          members of the Src family the SH2 domain in addition to
          binding the target, also plays an autoinhibitory role
          by binding to its C-terminal tail.  In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 96

 Score = 58.3 bits (141), Expect = 4e-11
 Identities = 30/84 (35%), Positives = 46/84 (54%), Gaps = 6/84 (7%)

Query: 13 WYFGMMTRQEAQ-AILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          WYFG + R EA+  +LL E ++GAFL+RDS +   +Y L V++ + V HY I ++     
Sbjct: 5  WYFGKIKRIEAEKKLLLPENEHGAFLIRDSESRHNDYSLSVRDGDTVKHYRIRQLDEGG- 63

Query: 72 QTCYKIGDK-TFSDLPSLLAFYKV 94
             + I  + TF  L  L+  Y  
Sbjct: 64 ---FFIARRTTFRTLQELVEHYSK 84


>gnl|CDD|198218 cd10355, SH2_DAPP1_BAM32_like, Src homology 2 domain found in dual
           adaptor for phosphotyrosine and 3-phosphoinositides (
           DAPP1)/B lymphocyte adaptor molecule of 32 kDa
           (Bam32)-like proteins.  DAPP1/Bam32 contains a putative
           myristoylation site at its N-terminus, followed by a SH2
           domain, and a pleckstrin homology (PH) domain at its
           C-terminus. DAPP1 could potentially be recruited to the
           cell membrane by any of these domains. Its putative
           myristoylation site could facilitate the interaction of
           DAPP1 with the lipid bilayer. Its SH2 domain may also
           interact with phosphotyrosine residues on
           membrane-associated proteins such as activated tyrosine
           kinase receptors. And finally its PH domain exhibits a
           high-affinity interaction with the PtdIns(3,4,5)P(3)
           PtdIns(3,4)P(2) second messengers produced at the cell
           membrane following the activation of PI 3-kinases. DAPP1
           is thought to interact with both tyrosine phosphorylated
           proteins and 3-phosphoinositides and therefore may play
           a role in regulating the location and/or activity of
           such proteins(s) in response to agonists that elevate
           PtdIns(3,4,5)P(3) and PtdIns(3,4)P(2). This protein is
           likely to play an important role in triggering signal
           transduction pathways that lie downstream from receptor
           tyrosine kinases and PI 3-kinase. It is likely that
           DAPP1 functions as an adaptor to recruit other proteins
           to the plasma membrane in response to extracellular
           signals. In general SH2 domains are involved in signal
           transduction. They typically bind pTyr-containing
           ligands via two surface pockets, a pTyr and hydrophobic
           binding pocket, allowing proteins with SH2 domains to
           localize to tyrosine phosphorylated sites.
          Length = 92

 Score = 57.9 bits (140), Expect = 4e-11
 Identities = 30/92 (32%), Positives = 47/92 (51%), Gaps = 10/92 (10%)

Query: 12  SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
            WY G +TR  A+A+LLS   +G++L+R+SN   G + L V+  + V H+ +        
Sbjct: 7   GWYHGNLTRHAAEALLLSNGVDGSYLLRNSNEGTGLFSLSVRAKDSVKHFHV-----EYT 61

Query: 72  QTCYKIGDKTFSDLPSLLAFYKVHYLDTSPLI 103
              +K G   F++  SL  F  V +    PLI
Sbjct: 62  GYSFKFG---FNEFSSLQDF--VKHFANQPLI 88


>gnl|CDD|198197 cd09944, SH2_Grb7_family, Src homology 2 (SH2) domain found in
          the growth factor receptor bound, subclass 7 (Grb7)
          proteins.  The Grb family binds to the epidermal growth
          factor receptor (EGFR, erbB1) via their SH2 domains.
          There are 3 members of the Grb7 family of proteins:
          Grb7, Grb10, and Grb14. They are composed of an
          N-terminal Proline-rich domain, a Ras Associating-like
          (RA) domain, a Pleckstrin Homology (PH) domain, a
          phosphotyrosine interaction region (PIR, BPS) and a
          C-terminal SH2 domain. The SH2 domains of Grb7, Grb10
          and Grb14 preferentially bind to a different RTK. Grb7
          binds strongly to the erbB2 receptor, unlike Grb10 and
          Grb14 which bind weakly to it. Grb14 binds to
          Fibroblast Growth Factor Receptor (FGFR). Grb10 has
          been shown to interact with many different proteins,
          including the insulin and IGF1 receptors,
          platelet-derived growth factor (PDGF) receptor-beta,
          Ret, Kit, Raf1 and MEK1, and Nedd4.  Grb7 family
          proteins are phosphorylated on serine/threonine as well
          as tyrosine residues. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 108

 Score = 57.0 bits (138), Expect = 1e-10
 Identities = 31/91 (34%), Positives = 47/91 (51%), Gaps = 6/91 (6%)

Query: 8  HDRNSWYFGMMTRQEAQAIL--LSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINK 65
          H    W+ G ++R EA  ++      D G FLVR+S +  G +VL +K   K+ HY I  
Sbjct: 2  HRSQPWFHGGISRDEAARLIRQQGLVD-GVFLVRESQSNPGAFVLSLKHGQKIKHYQIIP 60

Query: 66 ITNTEQQTCYKI--GDKTFSDLPSLLAFYKV 94
          I + E Q  + +  G   F DL  L+ FY++
Sbjct: 61 IED-EGQWYFTLDDGVTKFYDLLQLVEFYQL 90


>gnl|CDD|198228 cd10365, SH2_Src_Src, Src homology 2 (SH2) domain found in
          tyrosine kinase sarcoma (Src).  Src is a member of the
          Src non-receptor type tyrosine kinase family of
          proteins. Src is thought to play a role in the
          regulation of embryonic development and cell growth.
          Members here include v-Src and c-Src. v-Src lacks the
          C-terminal inhibitory phosphorylation site and is
          therefore constitutively active as opposed to normal
          cellular src (c-Src) which is only activated under
          certain circumstances where it is required (e.g. growth
          factor signaling). v-Src is an oncogene whereas c-Src
          is a proto-oncogene. c-Src consists of three domains,
          an N-terminal SH3 domain, a central SH2 domain and a
          tyrosine kinase domain. The SH2 and SH3 domains work
          together in the auto-inhibition of the kinase domain.
          The phosphorylation of an inhibitory tyrosine near the
          c-terminus of the protein produces a binding site for
          the SH2 domain which then facilitates binding of the
          SH3 domain to a polyproline site within the linker
          between the SH2 domain and the kinase domain. Binding
          of the SH3 domain inactivates the enzyme. This allows
          for multiple mechanisms for c-Src activation:
          dephosphorylation of the C-terminal tyrosine by a
          protein tyrosine phosphatase, binding of the SH2 domain
          by a competitive phospho-tyrosine residue, or
          competitive binding of a polyproline binding site to
          the SH3 domain.  Unlike most other Src members Src
          lacks cysteine residues in the SH4 domain that undergo
          palmitylation. Serine and threonine phosphorylation
          sites have also been identified in the unique domains
          of Src and are believed to modulate protein-protein
          interactions or regulate catalytic activity.
          Alternatively spliced forms of Src, which contain 6- or
          11-amino acid insertions in the SH3 domain, are
          expressed in CNS neurons. c-Src has a unique N-terminal
          domain, an SH3 domain, an SH2 domain, a kinase domain
          and a regulatory tail, as do the other members of the
          family. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 56.6 bits (136), Expect = 2e-10
 Identities = 35/89 (39%), Positives = 48/89 (53%), Gaps = 9/89 (10%)

Query: 13 WYFGMMTRQEAQAILLS-EKDNGAFLVRDSNTILGNYVLCVK--ENNK---VSHYIINKI 66
          WYFG +TR+E++ +LL+ E   G FLVR+S T  G Y L V   +N K   V HY I K+
Sbjct: 5  WYFGKITRRESERLLLNAENPRGTFLVRESETTKGAYCLSVSDFDNAKGLNVKHYKIRKL 64

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
             +    Y      F+ L  L+A+Y  H
Sbjct: 65 ---DSGGFYITSRTQFNSLQQLVAYYSKH 90


>gnl|CDD|212783 cd11849, SH3_SPIN90, Src homology 3 domain of SH3 protein
           interacting with Nck, 90 kDa (SPIN90).  SPIN90 is also
           called NCK interacting protein with SH3 domain
           (NCKIPSD), Dia-interacting protein (DIP), 54 kDa
           vimentin-interacting protein (VIP54), or
           WASP-interacting SH3-domain protein (WISH). It is an
           F-actin binding protein that regulates actin
           polymerization and endocytosis. It associates with the
           Arp2/3 complex near actin filaments and determines
           filament localization at the leading edge of
           lamellipodia. SPIN90 is expressed in the early stages of
           neuronal differentiation and plays a role in regulating
           growth cone dynamics and neurite outgrowth. It also
           interacts with IRSp53 and regulates cell motility by
           playing a role in the formation of membrane protrusions.
           SPIN90 contains an N-terminal SH3 domain, a proline-rich
           domain, and a C-terminal VCA (verprolin-homology and
           cofilin-like acidic) domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 54.6 bits (132), Expect = 2e-10
 Identities = 18/50 (36%), Positives = 28/50 (56%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A YDF   +P+ L F + +  +++ +   HWW   N SGE G +P  YV+
Sbjct: 4   ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLVTNHSGETGYVPANYVK 53


>gnl|CDD|198189 cd09935, SH2_ABL, Src homology 2 (SH2) domain found in Abelson
          murine lymphosarcoma virus (ABL) proteins.  ABL-family
          proteins are highly conserved tyrosine kinases. Each
          ABL protein contains an SH3-SH2-TK (Src homology 3-Src
          homology 2-tyrosine kinase) domain cassette, which
          confers autoregulated kinase activity and is common
          among nonreceptor tyrosine kinases. Several types of
          posttranslational modifications control ABL catalytic
          activity, subcellular localization, and stability, with
          consequences for both cytoplasmic and nuclear ABL
          functions. Binding partners provide additional
          regulation of ABL catalytic activity, substrate
          specificity, and downstream signaling. By combining
          this cassette with actin-binding and -bundling domain,
          ABL proteins are capable of connecting
          phosphoregulation with actin-filament reorganization.
          Vertebrate paralogs, ABL1 and ABL2, have evolved to
          perform specialized functions. ABL1 includes nuclear
          localization signals and a DNA binding domain which is
          used to mediate DNA damage-repair functions, while ABL2
          has additional binding capacity for actin and for
          microtubules to enhance its cytoskeletal remodeling
          functions.  SH2 is involved in several autoinhibitory
          mechanism that constrain the enzymatic activity of the
          ABL-family kinases. In one mechanism SH2 and SH3 cradle
          the kinase domain while a cap sequence stabilizes the
          inactive conformation resulting in a locked inactive
          state. Another involves phosphatidylinositol
          4,5-bisphosphate (PIP2) which binds the SH2 domain
          through residues normally required for phosphotyrosine
          binding in the linker segment between the SH2 and
          kinase domains. The SH2 domain contributes to ABL
          catalytic activity and target site specificity. It is
          thought that the ABL catalytic site and SH2 pocket have
          coevolved to recognize the same sequences. Recent work
          now supports a hierarchical processivity model in which
          the substrate target site most compatible with ABL
          kinase domain preferences is phosphorylated with
          greatest efficiency. If this site is compatible with
          the ABL SH2 domain specificity, it will then reposition
          and dock in the SH2 pocket. This mechanism also
          explains how ABL kinases phosphorylates poor targets on
          the same substrate if they are properly positioned and
          how relatively poor substrate proteins might be
          recruited to ABL through a complex with strong
          substrates that can also dock with the SH2 pocket. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 94

 Score = 55.9 bits (135), Expect = 2e-10
 Identities = 26/87 (29%), Positives = 47/87 (54%), Gaps = 4/87 (4%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITN 68
          +++SWY G ++R  A+  LLS   NG+FLVR+S +  G Y + ++ + +V HY I++   
Sbjct: 1  EKHSWYHGPISRNAAE-YLLSSGINGSFLVRESESSPGQYSISLRYDGRVYHYRISE--- 56

Query: 69 TEQQTCYKIGDKTFSDLPSLLAFYKVH 95
                Y   +  F+ L  L+  +  +
Sbjct: 57 DSDGKVYVTQEHRFNTLAELVHHHSKN 83


>gnl|CDD|198224 cd10361, SH2_Fps_family, Src homology 2 (SH2) domain found in
          feline sarcoma, Fujinami poultry sarcoma, and
          fes-related (Fes/Fps/Fer) proteins.  The Fps family
          consists of members Fps/Fes and Fer/Flk/Tyk3. They are
          cytoplasmic protein-tyrosine kinases implicated in
          signaling downstream from cytokines, growth factors and
          immune receptors.  Fes/Fps/Fer contains three
          coiled-coil regions, an SH2 (Src-homology-2) and a TK
          (tyrosine kinase catalytic) domain signature. Members
          here include: Fps/Fes, Fer, Kin-31, and  In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 90

 Score = 56.0 bits (136), Expect = 2e-10
 Identities = 24/93 (25%), Positives = 48/93 (51%), Gaps = 10/93 (10%)

Query: 6  DPHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDS---NTILGNYVLCVKENNKVSHYI 62
             +   +Y G++ R++A+ +L   K++G FLVR +          VL V+ + K+ H++
Sbjct: 1  KDLENEPYYHGLLPREDAEELL---KNDGDFLVRKTEPKGGGKRKLVLSVRWDGKIRHFV 57

Query: 63 INKITNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
          IN+  +  +   Y I  K+F  +  L+ +Y+  
Sbjct: 58 INR-DDGGK---YYIEGKSFKSISELINYYQKT 86


>gnl|CDD|212739 cd11805, SH3_GRB2_like_C, C-terminal Src homology 3 domain of
           Growth factor receptor-bound protein 2 (GRB2) and
           related proteins.  This family includes the adaptor
           protein GRB2 and related proteins including Drosophila
           melanogaster Downstream of receptor kinase (DRK),
           Caenorhabditis elegans Sex muscle abnormal protein 5
           (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and
           similar proteins. Family members contain an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. GRB2/Sem-5/DRK is a critical signaling molecule
           that regulates the Ras pathway by linking tyrosine
           kinases to the Ras guanine nucleotide releasing protein
           Sos (son of sevenless), which converts Ras to the active
           GTP-bound state. GRAP2 plays an important role in T cell
           receptor (TCR) signaling by promoting the formation of
           the SLP-76:LAT complex, which couples the TCR to the Ras
           pathway. GRAP acts as a negative regulator of T cell
           receptor (TCR)-induced lymphocyte proliferation by
           downregulating the signaling to the Ras/ERK pathway. The
           C-terminal SH3 domains (SH3c) of GRB2 and GRAP2 have
           been shown to bind to classical PxxP motif ligands, as
           well as to non-classical motifs. GRB2 SH3c binds Gab2
           (Grb2-associated binder 2) through epitopes containing
           RxxK motifs, while the SH3c of GRAP2 binds to the
           phosphatase-like protein HD-PTP via a RxxxxK motif. SH3
           domains are protein interaction domains that typically
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 54.2 bits (131), Expect = 3e-10
 Identities = 20/54 (37%), Positives = 31/54 (57%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +V A YDF+  +P +L F++ DI+ V+   +  WW  + + G VG  P  YVQ 
Sbjct: 1   RVQALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGE-LRGRVGIFPANYVQP 53



 Score = 40.3 bits (95), Expect = 3e-05
 Identities = 14/32 (43%), Positives = 20/32 (62%)

Query: 229 GDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           GDII V  ++    W+GEL G+ G FP  +V+
Sbjct: 21  GDIITVLDSSDPDWWKGELRGRVGIFPANYVQ 52


>gnl|CDD|198206 cd10343, SH2_SHIP, Src homology 2 (SH2) domain found in
          SH2-containing inositol-5'-phosphatase (SHIP) and
          SLAM-associated protein (SAP).  The SH2-containing
          inositol-5'-phosphatase, SHIP (also called
          SHIP1/SHIP1a), is a hematopoietic-restricted
          phosphatidylinositide phosphatase that translocates to
          the plasma membrane after extracellular stimulation and
          hydrolyzes the phosphatidylinositol-3-kinase
          (PI3K)-generated second messenger PI-3,4,5-P3 (PIP3) to
          PI-3,4-P2. As a result, SHIP dampens down PIP3 mediated
          signaling and represses the proliferation,
          differentiation, survival, activation, and migration of
          hematopoietic cells.  PIP3 recruits lipid-binding
          pleckstrin homology(PH) domain-containing proteins to
          the inner wall of the plasma membrane and activates
          them. PH domain-containing downstream effectors include
          the survival/proliferation enhancing serine/threonine
          kinase, Akt (protein kinase B), the tyrosine kinase,
          Btk, the regulator of protein translation, S6K, and the
          Rac and cdc42 guanine nucleotide exchange factor, Vav.
          SHIP is believed to act  as a tumor suppressor during
          leukemogenesis and lymphomagenesis, and may play a role
          in activating the immune system to combat cancer. SHIP
          contains an N-terminal SH2 domain, a centrally located
          phosphatase domain that specifically hydrolyzes the
          5'-phosphate from PIP3, PI-4,5-P2  and
          inositol-1,3,4,5- tetrakisphosphate (IP4), a C2 domain,
          that is an allosteric activating site when bound by
          SHIP's enzymatic product, PI-3,4-P2; 2 NPXY motifs that
          bind proteins with a phosphotyrosine binding (Shc, Dok
          1, Dok 2) or an SH2 (p85a, SHIP2) domain; and a
          proline-rich domain consisting of four PxxP motifs that
          bind a subset of SH3-containing proteins including
          Grb2, Src, Lyn, Hck, Abl, PLCg1, and PIAS1. The SH2
          domain of SHIP binds to the tyrosine phosphorylated
          forms of Shc, SHP-2, Doks, Gabs, CD150,
          platelet-endothelial cell adhesion molecule, Cas,
          c-Cbl, immunoreceptor tyrosine-based inhibitory motifs
          (ITIMs), and immunoreceptor tyrosine-based activation
          motifs (ITAMs). The X-linked lymphoproliferative
          syndrome (XLP) gene encodes SAP (also called
          SH2D1A/DSHP) a protein that consists of a 5 residue
          N-terminus, a single SH2 domain, and a short 25 residue
          C-terminal tail.  XLP is characterized by an extreme
          sensitivity to Epstein-Barr virus.  Both T and natural
          killer (NK) cell dysfunctions have been seen in XLP
          patients. SAP binds the cytoplasmic tail of Signaling
          lymphocytic activation molecule (SLAM), 2B4, Ly-9, and
          CD84. SAP is believed to function as a signaling
          inhibitor, by blocking or regulating binding of other
          signaling proteins. SAP and the SAP-like protein EAT-2
          recognize the sequence motif TIpYXX(V/I), which is
          found in the cytoplasmic domains of a restricted number
          of T, B, and NK cell surface receptors and are proposed
          to be natural inhibitors or regulators of the
          physiological role of a small family of receptors on
          the surface of these cells. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 103

 Score = 55.9 bits (135), Expect = 3e-10
 Identities = 32/86 (37%), Positives = 46/86 (53%), Gaps = 6/86 (6%)

Query: 12 SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
           WY G +TR +A+ +L     +G+FLVRDS ++ G Y LCV   N V  Y I  + N E 
Sbjct: 4  PWYHGNITRSKAEELLSKAGKDGSFLVRDSESVSGAYALCVLYQNCVHTYRI--LPNAED 61

Query: 72 ----QTCYKIGDKTFSDLPSLLAFYK 93
              Q    +  + F+ LP L+ FY+
Sbjct: 62 KLSVQASEGVPVRFFTTLPELIEFYQ 87


>gnl|CDD|212774 cd11840, SH3_Intersectin_5, Fifth Src homology 3 domain (or SH3E)
           of Intersectin.  Intersectins (ITSNs) are adaptor
           proteins that function in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction.
           They are essential for initiating clathrin-coated pit
           formation. They bind to many proteins through their
           multidomain structure and facilitate the assembly of
           multimeric complexes. Vertebrates contain two ITSN
           proteins, ITSN1 and ITSN2, which exist in alternatively
           spliced short and long isoforms. The short isoforms
           contain two Eps15 homology domains (EH1 and EH2), a
           coiled-coil region and five SH3 domains (SH3A-E), while
           the long isoforms, in addition, contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin homology (PH)
           and C2 domains. ITSN1 and ITSN2 are both widely
           expressed, with variations depending on tissue type and
           stage of development. The fifth SH3 domain (or SH3E) of
           ITSN1 has been shown to bind many protein partners
           including SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2,
           N-WASP, and synaptojanin-1, among others. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 53.2 bits (128), Expect = 8e-10
 Identities = 20/53 (37%), Positives = 34/53 (64%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +VIA + +   + D+L F+K DI+ V+SKD+  WW  + ++G+ G  P  YV+
Sbjct: 1   QVIALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGE-LNGQTGLFPSNYVE 52



 Score = 35.1 bits (81), Expect = 0.003
 Identities = 19/44 (43%), Positives = 25/44 (56%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
            A ++  L  + GDII V   +    W GELNG+TG FP  +VE
Sbjct: 9   TAQNEDELSFQKGDIINVLSKDDPDWWRGELNGQTGLFPSNYVE 52


>gnl|CDD|212779 cd11845, SH3_Src_like, Src homology 3 domain of Src kinase-like
           Protein Tyrosine Kinases.  Src subfamily members include
           Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk.
           Src (or c-Src) proteins are cytoplasmic (or
           non-receptor) PTKs which are anchored to the plasma
           membrane. They contain an N-terminal SH4 domain with a
           myristoylation site, followed by SH3 and SH2 domains, a
           tyr kinase domain, and a regulatory C-terminal region
           containing a conserved tyr. They are activated by
           autophosphorylation at the tyr kinase domain, but are
           negatively regulated by phosphorylation at the
           C-terminal tyr by Csk (C-terminal Src Kinase). However,
           Brk lacks the N-terminal myristoylation sites. Src
           proteins are involved in signaling pathways that
           regulate cytokine and growth factor responses,
           cytoskeleton dynamics, cell proliferation, survival, and
           differentiation. They were identified as the first
           proto-oncogene products, and they regulate cell
           adhesion, invasion, and motility in cancer cells, and
           tumor vasculature, contributing to cancer progression
           and metastasis. Src kinases are overexpressed in a
           variety of human cancers, making them attractive targets
           for therapy. They are also implicated in acute
           inflammatory responses and osteoclast function. Src,
           Fyn, Yes, and Yrk are widely expressed, while Blk, Lck,
           Hck, Fgr, Lyn, and Brk show a limited expression
           pattern. This subfamily also includes Drosophila Src42A,
           Src oncogene at 42A (also known as Dsrc41) which
           accumulates at sites of cell-cell or cell-matrix
           adhesion, and participates in Drosphila development and
           wound healing. It has been shown to promote tube
           elongation in the tracheal system, is essential for
           proper cell-cell matching during dorsal closure, and
           regulates cell-cell contacts in developing Drosophila
           eyes. The SH3 domain of Src kinases contributes to
           substrate recruitment by binding adaptor
           proteins/substrates, and regulation of kinase activity
           through an intramolecular interaction. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 53.0 bits (128), Expect = 9e-10
 Identities = 20/51 (39%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNIS-GEVGSIPVPY 162
            +A YD++    DDL FKK D L ++   +  WW A+++S G+ G IP  Y
Sbjct: 2   YVALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHLSTGKEGYIPSNY 52


>gnl|CDD|199829 cd10341, SH2_N-SH2_PLC_gamma_like, N-terminal Src homology 2
           (N-SH2) domain in Phospholipase C gamma.  Phospholipase
           C gamma is a signaling molecule that is recruited to the
           C-terminal tail of the receptor upon autophosphorylation
           of a highly conserved tyrosine.  PLCgamma is composed of
           a Pleckstrin homology (PH) domain followed by an
           elongation factor (EF) domain, 2 catalytic regions of
           PLC domains that flank 2 tandem SH2 domains (N-SH2,
           C-SH2), and ending with a SH3 domain and C2 domain.
           N-SH2 SH2 domain-mediated interactions represent a
           crucial step in transmembrane signaling by receptor
           tyrosine kinases. SH2 domains recognize phosphotyrosine
           (pY) in the context of particular sequence motifs in
           receptor phosphorylation sites. Both N-SH2 and C-SH2
           have a very similar binding affinity to pY. But in
           growth factor stimulated cells these domains bind to
           different target proteins. N-SH2 binds to pY containing
           sites in the C-terminal tails of tyrosine kinases and
           other receptors. Recently it has been shown that this
           interaction is mediated by phosphorylation-independent
           interactions between a secondary binding site found
           exclusively on the N-SH2 domain and a region of the
           FGFR1 tyrosine kinase domain. This secondary site on the
           SH2 cooperates with the canonical pY site to regulate
           selectivity in mediating a specific cellular process.
           C-SH2 binds to an intramolecular site on PLCgamma itself
           which allows it to hydrolyze
           phosphatidylinositol-4,5-bisphosphate into
           diacylglycerol and inositol triphosphate. These then
           activate protein kinase C and release calcium. In
           general SH2 domains are involved in signal transduction.
           They typically bind pTyr-containing ligands via two
           surface pockets, a pTyr and hydrophobic binding pocket,
           allowing proteins with SH2 domains to localize to
           tyrosine phosphorylated sites.
          Length = 99

 Score = 54.3 bits (131), Expect = 1e-09
 Identities = 30/97 (30%), Positives = 46/97 (47%), Gaps = 4/97 (4%)

Query: 8   HDRNSWYFGMMT--RQEAQAILLS--EKDNGAFLVRDSNTILGNYVLCVKENNKVSHYII 63
           H    W+ G +   R EA+ +LL   E  +G FLVR+S T +G+Y L    N KV H  I
Sbjct: 1   HFTEPWFHGKLGDGRDEAEKLLLEYCEGGDGTFLVRESETFVGDYTLSFWRNGKVQHCRI 60

Query: 64  NKITNTEQQTCYKIGDKTFSDLPSLLAFYKVHYLDTS 100
                  ++  Y   +  F  L  L+ +Y+ + L  +
Sbjct: 61  RSRQENGEKKYYLTDNLVFDSLYELIDYYRQNPLRCA 97


>gnl|CDD|198215 cd10352, SH2_a2chimerin_b2chimerin, Src homology 2 (SH2) domain
          found in alpha2-chimerin and beta2-chimerin proteins.
          Chimerins are a family of phorbol ester- and
          diacylglycerol-responsive GTPase-activating proteins.
          Alpha1-chimerin (formerly known as n-chimerin) and
          alpha2-chimerin are alternatively spliced products of a
          single gene, as are beta1- and beta2-chimerin. alpha1-
          and beta1-chimerin have a relatively short N-terminal
          region that does not encode any recognizable domains,
          whereas alpha2- and beta2-chimerin both include a
          functional SH2 domain that can bind to phosphotyrosine
          motifs within receptors. All of the isoforms contain a
          GAP domain with specificity in vitro for Rac1 and a
          diacylglycerol (DAG)-binding C1 domain which allows
          them to translocate to membranes in response to DAG
          signaling and anchors them in close proximity to
          activated Rac. Other C1 domain-containing
          diacylglycerol receptors including: PKC, Munc-13
          proteins, phorbol ester binding scaffolding proteins
          involved in Ca2+-stimulated exocytosis, and RasGRPs,
          diacylglycerol-activated guanine-nucleotide exchange
          factors (GEFs) for Ras and Rap1. In general SH2 domains
          are involved in signal transduction. They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 91

 Score = 53.9 bits (130), Expect = 1e-09
 Identities = 25/80 (31%), Positives = 45/80 (56%), Gaps = 4/80 (5%)

Query: 11 NSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
             Y G+++R+EA   LLS   +G++L+R+S+   G Y L ++ N KV +Y   K+    
Sbjct: 6  GREYHGLISREEA-EQLLSGASDGSYLIRESSRDDGYYTLSLRFNGKVKNY---KLYYDG 61

Query: 71 QQTCYKIGDKTFSDLPSLLA 90
          +   + +G+K F  +  L+A
Sbjct: 62 KNHYHYVGEKRFDTIHDLVA 81


>gnl|CDD|212838 cd11905, SH3_Tec, Src Homology 3 domain of Tec (Tyrosine kinase
           expressed in hepatocellular carcinoma).  Tec is a
           cytoplasmic (or nonreceptor) tyr kinase containing Src
           homology protein interaction domains (SH3, SH2)
           N-terminal to the catalytic tyr kinase domain. It also
           contains an N-terminal pleckstrin homology (PH) domain,
           which binds the products of PI3K and allows membrane
           recruitment and activation, and the Tec homology (TH)
           domain, which contains proline-rich and zinc-binding
           regions. It is more widely-expressed than other Tec
           subfamily kinases. Tec is found in endothelial cells,
           both B- and T-cells, and a variety of myeloid cells
           including mast cells, erythroid cells, platelets,
           macrophages and neutrophils. Tec is a key component of
           T-cell receptor (TCR) signaling, and is important in
           TCR-stimulated proliferation, IL-2 production and
           phospholipase C-gamma1 activation. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 51.4 bits (123), Expect = 5e-09
 Identities = 20/53 (37%), Positives = 32/53 (60%)

Query: 111 EKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           E V+A YDF   +P DL  +  +  +++ K++ HWW A++  G+ G IP  YV
Sbjct: 1   EIVVAMYDFQPTEPHDLRLETGEEYVILEKNDVHWWKARDKYGKEGYIPSNYV 53


>gnl|CDD|212776 cd11842, SH3_Ysc84p_like, Src homology 3 domain of Ysc84p and
           similar fungal proteins.  This family is composed of the
           Saccharomyces cerevisiae proteins, Ysc84p (also called
           LAS17-binding protein 4, Lsb4p) and Lsb3p, and similar
           fungal proteins. They contain an N-terminal SYLF domain
           (also called DUF500) and a C-terminal SH3 domain. Ysc84p
           localizes to actin patches and plays an important in
           actin polymerization during endocytosis. The N-terminal
           domain of both Ysc84p and Lsb3p can bind and bundle
           actin filaments. A study of the yeast SH3 domain
           interactome predicts that the SH3 domains of Lsb3p and
           Lsb4p may function as molecular hubs for the assembly of
           endocytic complexes. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 50.9 bits (122), Expect = 6e-09
 Identities = 23/55 (41%), Positives = 31/55 (56%), Gaps = 3/55 (5%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISGEVGSIPVPYVQ 164
           K +A YDF G  P DL F+K DI+ ++ K +    WWT + I G  G  P  YV+
Sbjct: 1   KAVALYDFAGEQPGDLAFQKGDIITILKKSDSQNDWWTGR-IGGREGIFPANYVE 54



 Score = 34.7 bits (80), Expect = 0.004
 Identities = 15/39 (38%), Positives = 21/39 (53%), Gaps = 2/39 (5%)

Query: 224 LKLEIGDIIKVTK--TNINGQWEGELNGKTGHFPFTHVE 260
           L  + GDII + K   + N  W G + G+ G FP  +VE
Sbjct: 16  LAFQKGDIITILKKSDSQNDWWTGRIGGREGIFPANYVE 54


>gnl|CDD|198186 cd09932, SH2_C-SH2_PLC_gamma_like, C-terminal Src homology 2
          (C-SH2) domain in Phospholipase C gamma.  Phospholipase
          C gamma is a signaling molecule that is recruited to
          the C-terminal tail of the receptor upon
          autophosphorylation of a highly conserved tyrosine.
          PLCgamma is composed of a Pleckstrin homology (PH)
          domain followed by an elongation factor (EF) domain, 2
          catalytic regions of PLC domains that flank 2 tandem
          SH2 domains (N-SH2, C-SH2), and ending with a SH3
          domain and C2 domain. N-SH2 SH2 domain-mediated
          interactions represent a crucial step in transmembrane
          signaling by receptor tyrosine kinases. SH2 domains
          recognize phosphotyrosine (pY) in the context of
          particular sequence motifs in receptor phosphorylation
          sites. Both N-SH2 and C-SH2 have a very similar binding
          affinity to pY. But in growth factor stimulated cells
          these domains bind to different target proteins. N-SH2
          binds to pY containing sites in the C-terminal tails of
          tyrosine kinases and other receptors. Recently it has
          been shown that this interaction is mediated by
          phosphorylation-independent interactions between a
          secondary binding site found exclusively on the N-SH2
          domain and a region of the FGFR1 tyrosine kinase
          domain. This secondary site on the SH2 cooperates with
          the canonical pY site to regulate selectivity in
          mediating a specific cellular process.  C-SH2 binds to
          an intramolecular site on PLCgamma itself which allows
          it to hydrolyze phosphatidylinositol-4,5-bisphosphate
          into diacylglycerol and inositol triphosphate. These
          then activate protein kinase C and release calcium. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 104

 Score = 52.3 bits (126), Expect = 6e-09
 Identities = 26/90 (28%), Positives = 47/90 (52%), Gaps = 5/90 (5%)

Query: 8  HDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKIT 67
          H+   W+   +TR++A+ +L+    +GAFLVR S T   ++ +  +   K+ H  I +  
Sbjct: 1  HESKEWFHANLTREQAEEMLMRVPRDGAFLVRPSETDPNSFAISFRAEGKIKHCRIKQ-- 58

Query: 68 NTEQQTCYKIGDKTFSDLPSLLAFYKVHYL 97
            E +  + IG   F  L  L+++Y+ H L
Sbjct: 59 --EGRL-FVIGTSQFESLVELVSYYEKHPL 85


>gnl|CDD|212716 cd11782, SH3_Sorbs_2, Second Src Homology 3 domain of Sorbin and
           SH3 domain containing (Sorbs) proteins and similar
           domains.  This family, also called the vinexin family,
           is composed predominantly of adaptor proteins containing
           one sorbin homology (SoHo) and three SH3 domains.
           Members include the second SH3 domains of Sorbs1 (or
           ponsin), Sorbs2 (or ArgBP2), Vinexin (or Sorbs3), and
           similar domains. They are involved in the regulation of
           cytoskeletal organization, cell adhesion, and growth
           factor signaling. Members of this family bind multiple
           partners including signaling molecules like c-Abl,
           c-Arg, Sos, and c-Cbl, as well as cytoskeletal molecules
           such as vinculin and afadin. They may have overlapping
           functions. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 50.4 bits (121), Expect = 1e-08
 Identities = 18/53 (33%), Positives = 32/53 (60%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +  AKY+F+ +   +L F+K D++ +  + +E+W+  + I G  G  PV YVQ
Sbjct: 1   EARAKYNFNADTGVELSFRKGDVITLTRRVDENWYEGR-IGGRQGIFPVSYVQ 52



 Score = 29.6 bits (67), Expect = 0.25
 Identities = 15/45 (33%), Positives = 25/45 (55%), Gaps = 2/45 (4%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           NA     L    GD+I +T+  ++  W EG + G+ G FP ++V+
Sbjct: 9   NADTGVELSFRKGDVITLTR-RVDENWYEGRIGGRQGIFPVSYVQ 52


>gnl|CDD|212884 cd11951, SH3_GRAP_C, C-terminal Src homology 3 domain of
           GRB2-related adaptor protein.  GRAP is a GRB-2 like
           adaptor protein that is highly expressed in lymphoid
           tissues. It acts as a negative regulator of T cell
           receptor (TCR)-induced lymphocyte proliferation by
           downregulating the signaling to the Ras/ERK pathway. It
           has been identified as a regulator of TGFbeta signaling
           in diabetic kidney tubules and may have a role in the
           pathogenesis of the disease. GRAP contains an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. The C-terminal SH3 domains (SH3c) of the related
           proteins, GRB2 and GRAP2, have been shown to bind to
           classical PxxP motif ligands, as well as to
           non-classical motifs. GRB2 SH3c binds Gab2
           (Grb2-associated binder 2) through epitopes containing
           RxxK motifs, while the SH3c of GRAP2 binds to the
           phosphatase-like protein HD-PTP via a RxxxxK motif. SH3
           domains are protein interaction domains that typically
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 50.2 bits (120), Expect = 1e-08
 Identities = 22/52 (42%), Positives = 30/52 (57%), Gaps = 1/52 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           V A+YDF   DP  L F++ DI+ V+   + +WW  + ISG VG  P  YV 
Sbjct: 2   VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGR-ISGRVGFFPRNYVH 52



 Score = 30.9 bits (70), Expect = 0.069
 Identities = 15/42 (35%), Positives = 21/42 (50%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           A D + L    GDII+V        W G ++G+ G FP  +V
Sbjct: 10  AEDPSQLSFRRGDIIEVLDCPDPNWWRGRISGRVGFFPRNYV 51


>gnl|CDD|212979 cd12046, SH3_p67phox_C, C-terminal (or second) Src Homology 3
           domain of the p67phox subunit of NADPH oxidase.
           p67phox, also called Neutrophil cytosol factor 2
           (NCF-2), is a cytosolic subunit of the phagocytic NADPH
           oxidase complex (also called Nox2 or gp91phox) which
           plays a crucial role in the cellular response to
           bacterial infection. NADPH oxidase catalyzes the
           transfer of electrons from NADPH to oxygen during
           phagocytosis forming superoxide and reactive oxygen
           species. p67phox plays a regulatory role and contains
           N-terminal TPR, first SH3 (or N-terminal or central
           SH3), PB1, and C-terminal SH3 domains. It binds, via its
           C-terminal SH3 domain, to a proline-rich region of
           p47phox and upon activation, this complex assembles with
           flavocytochrome b558, the Nox2-p22phox heterodimer.
           Concurrently, RacGTP translocates to the membrane and
           interacts with the TPR domain of p67phox, which leads to
           the activation of NADPH oxidase. The PB1 domain of
           p67phox binds to its partner PB1 domain in p40phox, and
           this facilitates the assembly of p47phox-p67phox at the
           membrane. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 50.2 bits (120), Expect = 1e-08
 Identities = 18/53 (33%), Positives = 34/53 (64%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V+A + ++ + P+DL F+K D+++V+SK  E W   Q   G++G  P  +V+
Sbjct: 1   QVVALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQ-CKGKIGIFPSAFVE 52



 Score = 32.1 bits (73), Expect = 0.029
 Identities = 16/38 (42%), Positives = 22/38 (57%), Gaps = 2/38 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           L+ + GD+I V  + +N  W EG+  GK G FP   VE
Sbjct: 16  LEFQKGDVILVL-SKVNEDWLEGQCKGKIGIFPSAFVE 52


>gnl|CDD|212792 cd11858, SH3_Myosin-I_fungi, Src homology 3 domain of Type I fungal
           Myosins.  Type I myosins (myosin-I) are actin-dependent
           motors in endocytic actin structures and actin patches.
           They play roles in membrane traffic in endocytic and
           secretory pathways, cell motility, and mechanosensing.
           Saccharomyces cerevisiae has two myosins-I, Myo3 and
           Myo5, which are involved in endocytosis and the
           polarization of the actin cytoskeleton. Myosin-I
           contains an N-terminal actin-activated ATPase, a
           phospholipid-binding TH1 (tail homology 1) domain, and a
           C-terminal extension which includes an F-actin-binding
           TH2 domain, an SH3 domain, and an acidic peptide that
           participates in activating the Arp2/3complex. The SH3
           domain of myosin-I is required for myosin-I-induced
           actin polymerization. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 50.1 bits (120), Expect = 1e-08
 Identities = 18/51 (35%), Positives = 31/51 (60%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEV-GSIPVPYVQ 164
           A YDF G+  ++L  KK+DI+ +V K++  WW A+ +     G +P  Y++
Sbjct: 4   ALYDFAGSVANELSLKKDDIVYIVQKEDNGWWLAKKLDESKEGWVPAAYLE 54


>gnl|CDD|199831 cd10369, SH2_Src_Frk, Src homology 2 (SH2) domain found in the
          Fyn-related kinase (Frk).  Frk is a member of the Src
          non-receptor type tyrosine kinase family of proteins.
          The Frk subfamily is composed of Frk/Rak and
          Iyk/Bsk/Gst. It is expressed primarily epithelial
          cells.  Frk is a nuclear protein and may function
          during G1 and S phase of the cell cycle and suppress
          growth. Unlike the other Src members it lacks a glycine
          at position 2 of SH4 which is important for addition of
          a myristic acid moiety that is involved in targeting
          Src PTKs to cellular membranes. FRK and SHB exert
          similar effects when overexpressed in rat
          phaeochromocytoma (PC12) and beta-cells, where both
          induce PC12 cell differentiation and beta-cell
          proliferation. Under conditions that cause beta-cell
          degeneration these proteins augment beta-cell
          apoptosis. The FRK-SHB responses involve FAK and
          insulin receptor substrates (IRS) -1 and -2. Frk has
          been demonstrated to interact with retinoblastoma
          protein. Frk regulates PTEN protein stability by
          phosphorylating PTEN, which in turn prevents PTEN
          degradation. Frk also plays a role in regulation of
          embryonal pancreatic beta cell formation. Frk has a
          unique N-terminal domain, an SH3 domain, an SH2 domain,
          a kinase domain and a regulatory tail, as do the other
          members of the family.  Like the other members of the
          Src family the SH2 domain in addition to binding the
          target, also plays an autoinhibitory role by binding to
          its activation loop. The tryosine involved is at the
          same site as the tyrosine involved in the
          autophosphorylation of Src. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 96

 Score = 51.0 bits (122), Expect = 2e-08
 Identities = 28/81 (34%), Positives = 44/81 (54%), Gaps = 4/81 (4%)

Query: 13 WYFGMMTRQEAQAILL-SEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          W+FG + R +A+  LL SE   GAFL+R+S +  G + L V +   V HY I ++   ++
Sbjct: 5  WFFGAIKRADAEKQLLYSENQTGAFLIRESESQKGEFSLSVLDGGVVKHYRIRRL---DE 61

Query: 72 QTCYKIGDKTFSDLPSLLAFY 92
             +    KTFS L   + +Y
Sbjct: 62 GGFFLTRRKTFSTLNEFVNYY 82


>gnl|CDD|198193 cd09940, SH2_Vav_family, Src homology 2 (SH2) domain found in the
          Vav family.  Vav proteins are involved in several
          processes that require cytoskeletal reorganization,
          such as the formation of the immunological synapse
          (IS), phagocytosis, platelet aggregation, spreading,
          and transformation.  Vavs function as guanine
          nucleotide exchange factors (GEFs) for the Rho/Rac
          family of GTPases.  Vav family members have several
          conserved motifs/domains including: a leucine-rich
          region, a leucine-zipper, a calponin homology (CH)
          domain, an acidic domain, a Dbl-homology (DH) domain, a
          pleckstrin homology (PH) domain, a cysteine-rich
          domain, 2 SH3 domains,  a proline-rich region, and a
          SH2 domain.  Vavs are the only known Rho GEFs that have
          both the DH/PH motifs and SH2/SH3 domains in the same
          protein. The leucine-rich helix-loop-helix (HLH) domain
          is thought to be involved in protein heterodimerization
          with other HLH proteins and it may function as a
          negative regulator by forming inactive heterodimers.
          The CH domain  is usually involved in the association
          with filamentous actin, but in Vav it controls NFAT
          stimulation, Ca2+ mobilization, and its transforming
          activity. Acidic domains are involved in
          protein-protein interactions and contain regulatory
          tyrosines. The DH domain is a GDP-GTP exchange factor
          on Rho/Rac GTPases. The PH domain in involved in
          interactions with GTP-binding proteins, lipids and/or
          phosphorylated serine/threonine residues. The SH3
          domain is involved in localization of proteins to
          specific sites within the cell interacting with protein
          with proline-rich sequences.  The SH2 domain mediates a
          high affinity interaction with tyrosine phosphorylated
          proteins.  There are three Vav mammalian family
          members: Vav1 which is expressed in the hematopoietic
          system, Vav2 and Vav3 are more ubiquitously expressed.
          The members here include insect and amphibian Vavs. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 102

 Score = 51.1 bits (123), Expect = 2e-08
 Identities = 24/86 (27%), Positives = 36/86 (41%), Gaps = 6/86 (6%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          W+ G M R  A+  L +  D G +LVR        Y L +K N  V H  I +       
Sbjct: 7  WFVGEMERDTAENRLENRPD-GTYLVRVRPQGETQYALSIKYNGDVKHMKIEQ----RSD 61

Query: 73 TCYKIGDKT-FSDLPSLLAFYKVHYL 97
            Y + +   F  L  L+ +Y+ + L
Sbjct: 62 GLYYLSESRHFKSLVELVNYYERNSL 87


>gnl|CDD|212911 cd11978, SH3_VAV3_2, C-terminal (or second) Src homology 3 domain
           of VAV3 protein.  VAV3 is ubiquitously expressed and
           functions as a phosphorylation-dependent guanine
           nucleotide exchange factor (GEF) for RhoA, RhoG, and
           Rac1. It has been implicated to function in the
           hematopoietic, bone, cerebellar, and cardiovascular
           systems. VAV3 is essential in axon guidance in neurons
           that control blood pressure and respiration. It is
           overexpressed in prostate cancer cells and it plays a
           role in regulating androgen receptor transcriptional
           activity. VAV proteins contain several domains that
           enable their function: N-terminal calponin homology
           (CH), acidic, RhoGEF (also called Dbl-homologous or DH),
           Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two
           SH3 domains. The SH3 domain of VAV is involved in the
           localization of proteins to specific sites within the
           cell, by interacting with proline-rich sequences within
           target proteins. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 56

 Score = 49.6 bits (118), Expect = 2e-08
 Identities = 22/44 (50%), Positives = 29/44 (65%), Gaps = 1/44 (2%)

Query: 218 AYDKTALKLEIGDIIKV-TKTNINGQWEGELNGKTGHFPFTHVE 260
           A D   L L  GD++K+ TK + NG W GE+NG+ G FP T+VE
Sbjct: 11  ARDMRELSLLKGDVVKIYTKMSTNGWWRGEVNGRVGWFPSTYVE 54



 Score = 37.3 bits (86), Expect = 4e-04
 Identities = 17/52 (32%), Positives = 28/52 (53%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           IA+YDF   D  +L   K D++ + +K   + W    ++G VG  P  YV++
Sbjct: 4   IARYDFCARDMRELSLLKGDVVKIYTKMSTNGWWRGEVNGRVGWFPSTYVEE 55


>gnl|CDD|198179 cd09925, SH2_SHC, Src homology 2 (SH2) domain found in SH2
          adaptor protein C (SHC).  SHC is involved in a wide
          variety of pathways including regulating proliferation,
          angiogenesis, invasion and metastasis, and bone
          metabolism. An adapter protein, SHC has been implicated
          in Ras activation following the stimulation of a number
          of different receptors, including growth factors
          [insulin, epidermal growth factor (EGF), nerve growth
          factor, and platelet derived growth factor (PDGF)],
          cytokines [interleukins 2, 3, and 5], erythropoietin,
          and granulocyte/macrophage colony-stimulating factor,
          and antigens [T-cell and B-cell receptors]. SHC has
          been shown to bind to tyrosine-phosphorylated
          receptors, and receptor stimulation leads to tyrosine
          phosphorylation of SHC. Upon phosphorylation, SHC
          interacts with another adapter protein, Grb2, which
          binds to the Ras GTP/GDP exchange factor mSOS which
          leads to Ras activation. SHC is composed of an
          N-terminal domain that interacts with proteins
          containing phosphorylated tyrosines, a
          (glycine/proline)-rich collagen-homology domain that
          contains the phosphorylated binding site, and a
          C-terminal SH2 domain. SH2 has been shown to interact
          with the tyrosine-phosphorylated receptors of EGF and
          PDGF and with the tyrosine-phosphorylated C chain of
          the T-cell receptor, providing one of the mechanisms of
          T-cell-mediated Ras activation. In general SH2 domains
          are involved in signal transduction.  They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 50.8 bits (122), Expect = 2e-08
 Identities = 20/58 (34%), Positives = 34/58 (58%), Gaps = 3/58 (5%)

Query: 6  DPHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYII 63
          +      WY G M+R++A+++L   + +G FLVR+S T  G YVL   +N +  H ++
Sbjct: 2  EQLRGEPWYHGKMSRRDAESLL---QTDGDFLVRESTTTPGQYVLTGMQNGQPKHLLL 56


>gnl|CDD|212761 cd11827, SH3_MyoIe_If_like, Src homology 3 domain of Myosins Ie,
           If, and similar proteins.  Myosins Ie (MyoIe) and If
           (MyoIf) are nonmuscle, unconventional, long tailed,
           class I myosins containing an N-terminal motor domain
           and a myosin tail with TH1, TH2, and SH3 domains. MyoIe
           interacts with the endocytic proteins, dynamin and
           synaptojanin-1, through its SH3 domain; it may play a
           role in clathrin-dependent endocytosis. In the kidney,
           MyoIe is critical for podocyte function and normal
           glomerular filtration. Mutations in MyoIe is associated
           with focal segmental glomerulosclerosis, a disease
           characterized by massive proteinuria and progression to
           end-stage kidney disease. MyoIf is predominantly
           expressed in the immune system; it plays a role in
           immune cell motility and innate immunity. Mutations in
           MyoIf may be associated with the loss of hearing. The
           MyoIf gene has also been found to be fused to the MLL
           (Mixed lineage leukemia) gene in infant acute myeloid
           leukemias (AML). SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 49.0 bits (117), Expect = 2e-08
 Identities = 19/51 (37%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           A Y +D  D D+L F + DI+ ++ +D   WWT + + G+ G  P  YV+K
Sbjct: 4   ALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTGR-LRGKEGLFPGNYVEK 53



 Score = 40.5 bits (95), Expect = 3e-05
 Identities = 19/43 (44%), Positives = 24/43 (55%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           A D   L    GDII++ K + +G W G L GK G FP  +VE
Sbjct: 10  AQDTDELSFNEGDIIEILKEDPSGWWTGRLRGKEGLFPGNYVE 52


>gnl|CDD|198271 cd10408, SH2_Nck1, Src homology 2 (SH2) domain found in Nck.  Nck
          proteins are adaptors that modulate actin cytoskeleton
          dynamics by linking proline-rich effector molecules to
          tyrosine kinases or phosphorylated signaling
          intermediates. There are two members known in this
          family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth
          factor receptor-bound protein 4 (Grb4)). They are
          characterized by having 3 SH3 domains and a C-terminal
          SH2 domain. Nck1 and Nck2 have overlapping functions as
          determined by gene knockouts. Both bind receptor
          tyrosine kinases and other tyrosine-phosphorylated
          proteins through their SH2 domains. In addition they
          also bind distinct targets.  Neuronal signaling
          proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1)
          all bind to Nck-2 exclusively. And in the case of
          PDGFR, Tyr(P)751 binds to  Nck1 while Tyr(P)1009 binds
          to Nck2. Nck1 and Nck2 have a role in the infection
          process of enteropathogenic Escherichia coli (EPEC).
          Their SH3 domains are involved in recruiting and
          activating the N-WASP/Arp2/3 complex inducing actin
          polymerization resulting in the production of
          pedestals, dynamic bacteria-presenting protrusions of
          the plasma membrane. A similar thing occurs in the
          vaccinia virus where motile plasma membrane projections
          are formed beneath the virus. Recently it has been
          shown that the SH2 domains of both Nck1 and Nck2 bind
          the G-protein coupled receptor kinase-interacting
          protein 1 (GIT1) in a phosphorylation-dependent manner.
          In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 97

 Score = 49.6 bits (118), Expect = 4e-08
 Identities = 25/83 (30%), Positives = 43/83 (51%), Gaps = 5/83 (6%)

Query: 11 NSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
          N WY+G +TR +A+  L    + G FL+RDS +   ++ + +K   K  H+ +       
Sbjct: 1  NPWYYGKVTRHQAEMALNERGNEGDFLIRDSESSPNDFSVSLKAQGKNKHFKVQL----- 55

Query: 71 QQTCYKIGDKTFSDLPSLLAFYK 93
          ++  Y IG + FS +  L+  YK
Sbjct: 56 KECVYCIGQRKFSSMEELVEHYK 78


>gnl|CDD|198191 cd09938, SH2_N-SH2_Zap70_Syk_like, N-terminal Src homology 2
          (SH2) domain found in Zeta-chain-associated protein
          kinase 70 (ZAP-70) and Spleen tyrosine kinase (Syk)
          proteins.  ZAP-70 and Syk comprise a family of
          hematopoietic cell specific protein tyrosine kinases
          (PTKs) that are required for antigen and antibody
          receptor function. ZAP-70 is expressed in T and natural
          killer (NK) cells and Syk is expressed in B cells, mast
          cells, polymorphonuclear leukocytes, platelets,
          macrophages, and immature T cells. They are required
          for the proper development of T and B cells, immune
          receptors, and activating NK cells. They consist of two
          N-terminal Src homology 2 (SH2) domains and a
          C-terminal kinase domain separated from the SH2 domains
          by a linker or hinge region. Phosphorylation of both
          tyrosine residues within the Immunoreceptor
          Tyrosine-based Activation Motifs (ITAM; consensus
          sequence Yxx[LI]x(7,8)Yxx[LI]) by the Src-family PTKs
          is required for efficient interaction of ZAP-70 and Syk
          with the receptor subunits and for receptor function.
          ZAP-70 forms two phosphotyrosine binding pockets, one
          of which is shared by both SH2 domains.  In Syk the two
          SH2 domains do not form such a phosphotyrosine-binding
          site.  The SH2 domains here are believed to function
          independently. In addition, the two SH2 domains of Syk
          display flexibility in their relative orientation,
          allowing Syk to accommodate a greater variety of
          spacing sequences between the ITAM phosphotyrosines and
          singly phosphorylated non-classical ITAM ligands. This
          model contains the N-terminus SH2 domains of both Syk
          and Zap70. In general SH2 domains are involved in
          signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 49.7 bits (119), Expect = 5e-08
 Identities = 23/57 (40%), Positives = 33/57 (57%), Gaps = 1/57 (1%)

Query: 13 WYFGMMTRQEAQAIL-LSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITN 68
          +++G +TR+EA+  L L+   +G FL+R S   LG YVL V    K  HY I +  N
Sbjct: 3  FFYGSITREEAEEYLKLAGMSDGLFLLRQSLRSLGGYVLSVCHGRKFHHYTIERQLN 59


>gnl|CDD|198183 cd09929, SH2_BLNK_SLP-76, Src homology 2 (SH2) domain found in
          B-cell linker (BLNK) protein and SH2 domain-containing
          leukocyte protein of 76 kDa (SLP-76).  BLNK (also known
          as SLP-65 or BASH) is an important adaptor protein
          expressed in B-lineage cells. BLNK consists of a
          N-terminal sterile alpha motif (SAM) domain and a
          C-terminal SH2 domain.  BLNK is a cytoplasmic protein,
          but a part of it is bound to the plasma membrane
          through an N-terminal leucine zipper motif and
          transiently bound to a cytoplasmic domain of Iga
          through its C-terminal SH2 domain upon B cell antigen
          receptor (BCR)-stimulation. A non-ITAM phosphotyrosine
          in Iga is necessary for the binding with the BLNK SH2
          domain and/or for normal BLNK function in signaling and
          B cell activation. Upon phosphorylation BLNK binds Btk
          and PLCgamma2 through their SH2 domains and mediates
          PLCgamma2 activation by Btk. BLNK also binds other
          signaling molecules such as Vav, Grb2, Syk, and HPK1.
          BLNK has been shown to be necessary for BCR-mediated
          Ca2+ mobilization, for the activation of
          mitogen-activated protein kinases such as ERK, JNK, and
          p38 in a chicken B cell line DT40, and for activation
          of transcription factors such as NF-AT and NF-kappaB in
          human or mouse B cells. BLNK is involved in B cell
          development, B cell survival, activation,
          proliferation, and T-independent immune responses. BLNK
          is structurally homologous to SLP-76. SLP-76 and
          (linker for activation of T cells) LAT are
          adaptor/linker proteins in T cell antigen receptor
          activation and T cell development. BLNK interacts with
          many downstream signaling proteins that interact
          directly with both SLP-76 and  LAT.  New data suggest
          functional complementation of SLP-76 and LAT in T cell
          antigen receptor function with BLNK in BCR function. In
          general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 121

 Score = 50.4 bits (121), Expect = 5e-08
 Identities = 24/65 (36%), Positives = 33/65 (50%), Gaps = 2/65 (3%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGN--YVLCVKENNKVSHYIINKI 66
              WY G + R+EA+  L     +G FLVRDS+    +  Y L V  N+KV +  I  +
Sbjct: 9  LPKEWYAGNIDRKEAEEALRRSNKDGTFLVRDSSGKDSSQPYTLMVLYNDKVYNIQIRFL 68

Query: 67 TNTEQ 71
           NT Q
Sbjct: 69 ENTRQ 73


>gnl|CDD|212901 cd11968, SH3_SASH3, Src homology 3 domain of Sam And SH3 Domain
           Containing Protein 3.  SASH3, also called SLY/SLY1
           (SH3-domain containing protein expressed in
           lymphocytes), is expressed exclusively in lymhocytes and
           is essential in the full activation of adaptive
           immunity. It is involved in the signaling of T cell
           receptors. It was the first described member of the SLY
           family of proteins, which are adaptor proteins
           containing a central conserved region with a bipartite
           nuclear localization signal (NLS) as well as SAM
           (sterile alpha motif) and SH3 domains. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 48.3 bits (115), Expect = 5e-08
 Identities = 23/53 (43%), Positives = 32/53 (60%)

Query: 208 ARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           ARV    +P+ YD  +LKL+ GDII++ +    G W G LN K G F F +V+
Sbjct: 3   ARVHTDFIPSPYDGDSLKLQKGDIIQIIEKPPVGTWTGLLNNKVGTFKFIYVD 55



 Score = 26.4 bits (58), Expect = 3.7
 Identities = 13/41 (31%), Positives = 21/41 (51%), Gaps = 1/41 (2%)

Query: 123 DPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           D D L  +K DI+ ++ K     WT   ++ +VG+    YV
Sbjct: 15  DGDSLKLQKGDIIQIIEKPPVGTWTGL-LNNKVGTFKFIYV 54


>gnl|CDD|212747 cd11813, SH3_SGSM3, Src Homology 3 domain of Small G protein
           Signaling Modulator 3.  SGSM3 is also called
           Merlin-associated protein (MAP), RUN and SH3
           domain-containing protein (RUSC3), RUN and TBC1
           domain-containing protein 3 (RUTBC3), Rab
           GTPase-activating protein 5 (RabGAP5), or Rab GAP-like
           protein (RabGAPLP). It is expressed ubiquitously and
           functions as a regulator of small G protein RAP- and
           RAB-mediated neuronal signaling. It is involved in
           modulating NGF-mediated neurite outgrowth and
           differentiation. It also interacts with the tumor
           suppressor merlin and may play a role in the
           merlin-associated suppression of cell growth. SGSM3
           contains TBC, SH3, and RUN domains. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 53

 Score = 48.3 bits (115), Expect = 6e-08
 Identities = 19/50 (38%), Positives = 33/50 (66%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A  DF+ +D D+L F+KNDI+ ++S+ +EH W  + ++G  G  P  +V+
Sbjct: 4   ALLDFERHDDDELGFRKNDIITIISQKDEHCWVGE-LNGLRGWFPAKFVE 52



 Score = 29.4 bits (66), Expect = 0.28
 Identities = 16/42 (38%), Positives = 18/42 (42%)

Query: 219 YDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           +D   L     DII +        W GELNG  G FP   VE
Sbjct: 11  HDDDELGFRKNDIITIISQKDEHCWVGELNGLRGWFPAKFVE 52


>gnl|CDD|199832 cd10417, SH2_SH2D7, Src homology 2 domain found in the SH2 domain
          containing protein 7 (SH2D7).  SH2D7 contains a single
          SH2 domain. In general SH2 domains are involved in
          signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 102

 Score = 49.1 bits (117), Expect = 7e-08
 Identities = 26/83 (31%), Positives = 47/83 (56%), Gaps = 8/83 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          W+ G +TR++ +  LL +K  G+FL+R S+   G Y+L  + +++  H++IN+     + 
Sbjct: 9  WFHGFITRKQTEQ-LLRDKALGSFLIRLSDRATG-YILSYRGSDRCRHFVINQ----LRN 62

Query: 73 TCYKI-GDK-TFSDLPSLLAFYK 93
            Y I GD  + S L  L+  Y+
Sbjct: 63 RRYLISGDTSSHSTLAELVRHYQ 85


>gnl|CDD|212841 cd11908, SH3_ITK, Src Homology 3 domain of Interleukin-2-inducible
           T-cell Kinase.  ITK (also known as Tsk or Emt) is a
           cytoplasmic (or nonreceptor) tyr kinase containing Src
           homology protein interaction domains (SH3, SH2)
           N-terminal to the catalytic tyr kinase domain. It also
           contains an N-terminal pleckstrin homology (PH) domain,
           which binds the products of PI3K and allows membrane
           recruitment and activation, and the Tec homology (TH)
           domain, which contains proline-rich and zinc-binding
           regions. ITK is expressed in T-cells and mast cells, and
           is important in their development and differentiation.
           Of the three Tec kinases expressed in T-cells, ITK plays
           the predominant role in T-cell receptor (TCR) signaling.
           It is activated by phosphorylation upon TCR crosslinking
           and is involved in the pathway resulting in
           phospholipase C-gamma1 activation and actin
           polymerization. It also plays a role in the downstream
           signaling of the T-cell costimulatory receptor CD28, the
           T-cell surface receptor CD2, and the chemokine receptor
           CXCR4. In addition, ITK is crucial for the development
           of T-helper(Th)2 effector responses. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 48.1 bits (114), Expect = 7e-08
 Identities = 19/51 (37%), Positives = 29/51 (56%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           VIA YD+  NDP +L  + N+   ++   E HWW  Q+ +G  G +P  Y+
Sbjct: 3   VIALYDYQTNDPQELALRYNEEYHLLDSSEIHWWRVQDKNGHEGYVPSSYL 53


>gnl|CDD|198184 cd09930, SH2_cSH2_p85_like, C-terminal Src homology 2 (cSH2)
          domain found in p85.  Phosphoinositide 3-kinases
          (PI3Ks) are essential for cell growth, migration, and
          survival. p110, the catalytic subunit, is composed of
          an adaptor-binding domain, a Ras-binding domain, a C2
          domain, a helical domain, and a kinase domain.  The
          regulatory unit is called p85 and is composed of an SH3
          domain, a RhoGap domain, a N-terminal SH2 (nSH2)
          domain, a inter SH2 (iSH2) domain, and C-terminal
          (cSH2) domain.  There are 2 inhibitory interactions
          between p110alpha and p85 of P13K: 1) p85 nSH2 domain
          with the C2, helical, and kinase domains of p110alpha
          and 2) p85 iSH2 domain with C2 domain of p110alpha.
          There are 3 inhibitory interactions between p110beta
          and p85 of P13K: 1) p85 nSH2 domain with the C2,
          helical, and kinase domains of p110beta, 2) p85 iSH2
          domain with C2 domain of p110alpha, and 3) p85 cSH2
          domain with the kinase domain of p110alpha. It is
          interesting to note that p110beta is oncogenic as a
          wild type protein while p110alpha lacks this ability.
          One explanation is the idea that the regulation of
          p110beta by p85 is unique because of the addition of
          inhibitory contacts from the cSH2 domain and the loss
          of contacts in the iSH2 domain. In general SH2 domains
          are involved in signal transduction. They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 48.9 bits (117), Expect = 8e-08
 Identities = 22/58 (37%), Positives = 33/58 (56%), Gaps = 2/58 (3%)

Query: 8  HDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINK 65
          HD  +W  G + R +A+ +L   K +G FL+R+S+T  G Y   V  N +V H +I K
Sbjct: 3  HDERTWLVGDINRTQAEELLRG-KPDGTFLIRESST-QGCYACSVVCNGEVKHCVIYK 58


>gnl|CDD|212697 cd11763, SH3_SNX9_like, Src Homology 3 domain of Sorting Nexin 9
           and similar proteins.  Sorting nexins (SNXs) are Phox
           homology (PX) domain containing proteins that are
           involved in regulating membrane traffic and protein
           sorting in the endosomal system. SNXs differ from each
           other in their lipid-binding specificity, subcellular
           localization and specific function in the endocytic
           pathway. This subfamily consists of SH3 domain
           containing SNXs including SNX9, SNX18, SNX33, and
           similar proteins. SNX9 is localized to plasma membrane
           endocytic sites and acts primarily in clathrin-mediated
           endocytosis, while SNX18 is localized to peripheral
           endosomal structures, and acts in a trafficking pathway
           that is clathrin-independent but relies on AP-1 and
           PACS1. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 47.7 bits (114), Expect = 9e-08
 Identities = 19/54 (35%), Positives = 26/54 (48%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDIL-IVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           KV A YDFD     +L  +  ++L I      + W   +N  GEVG  P  YV+
Sbjct: 1   KVRALYDFDSQPSGELSLRAGEVLTITRQDVGDGWLEGRNSRGEVGLFPSSYVE 54



 Score = 34.2 bits (79), Expect = 0.005
 Identities = 17/56 (30%), Positives = 30/56 (53%), Gaps = 9/56 (16%)

Query: 212 QVRVPNAYDKTA-----LKLEIGDIIKVTKTNI-NGQWEGE-LNGKTGHFPFTHVE 260
           +VR    YD  +     L L  G+++ +T+ ++ +G  EG    G+ G FP ++VE
Sbjct: 1   KVRA--LYDFDSQPSGELSLRAGEVLTITRQDVGDGWLEGRNSRGEVGLFPSSYVE 54


>gnl|CDD|212699 cd11765, SH3_Nck_1, First Src Homology 3 domain of Nck adaptor
           proteins.  Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4), which show partly
           overlapping functions but also bind distinct targets.
           Their SH3 domains are involved in recruiting downstream
           effector molecules, such as the N-WASP/Arp2/3 complex,
           which when activated induces actin polymerization that
           results in the production of pedestals, or protrusions
           of the plasma membrane. The first SH3 domain of Nck
           proteins preferentially binds the PxxDY sequence, which
           is present in the CD3e cytoplasmic tail. This binding
           inhibits phosphorylation by Src kinases, resulting in
           the downregulation of TCR surface expression. SH3
           domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially a PxxP motif. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 51

 Score = 47.4 bits (113), Expect = 9e-08
 Identities = 21/51 (41%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           V+AKYD+      +L  KKN+ L ++  D +HWW  QN S + G +P  YV
Sbjct: 2   VVAKYDYTAQGDQELSIKKNEKLTLLD-DSKHWWKVQNSSNQTGYVPSNYV 51


>gnl|CDD|212764 cd11830, SH3_VAV_2, C-terminal (or second) Src homology 3 domain of
           VAV proteins.  VAV proteins function both as cytoplasmic
           guanine nucleotide exchange factors (GEFs) for Rho
           GTPases and scaffold proteins and they play important
           roles in cell signaling by coupling cell surface
           receptors to various effector functions. They play key
           roles in processes that require cytoskeletal
           reorganization including immune synapse formation,
           phagocytosis, cell spreading, and platelet aggregation,
           among others. Vertebrates have three VAV proteins (VAV1,
           VAV2, and VAV3). VAV proteins contain several domains
           that enable their function: N-terminal calponin homology
           (CH), acidic, RhoGEF (also called Dbl-homologous or DH),
           Pleckstrin Homology (PH), C1 (zinc finger), SH2, and two
           SH3 domains. The SH3 domain of VAV is involved in the
           localization of proteins to specific sites within the
           cell, by interacting with proline-rich sequences within
           target proteins. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 47.6 bits (113), Expect = 1e-07
 Identities = 20/44 (45%), Positives = 27/44 (61%), Gaps = 1/44 (2%)

Query: 218 AYDKTALKLEIGDIIKV-TKTNINGQWEGELNGKTGHFPFTHVE 260
           A D   L L+ GD++K+  K    G W GE+NG+ G FP T+VE
Sbjct: 10  ARDMRELSLKEGDVVKIYNKKGQQGWWRGEINGRIGWFPSTYVE 53



 Score = 39.2 bits (91), Expect = 1e-04
 Identities = 17/53 (32%), Positives = 31/53 (58%), Gaps = 2/53 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSK-DEEHWWTAQNISGEVGSIPVPYVQK 165
            A+YDF   D  +L  K+ D++ + +K  ++ WW  + I+G +G  P  YV++
Sbjct: 3   KARYDFCARDMRELSLKEGDVVKIYNKKGQQGWWRGE-INGRIGWFPSTYVEE 54


>gnl|CDD|212738 cd11804, SH3_GRB2_like_N, N-terminal Src homology 3 domain of
           Growth factor receptor-bound protein 2 (GRB2) and
           related proteins.  This family includes the adaptor
           protein GRB2 and related proteins including Drosophila
           melanogaster Downstream of receptor kinase (DRK),
           Caenorhabditis elegans Sex muscle abnormal protein 5
           (Sem-5), GRB2-related adaptor protein (GRAP), GRAP2, and
           similar proteins. Family members contain an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. GRB2/Sem-5/DRK is a critical signaling molecule
           that regulates the Ras pathway by linking tyrosine
           kinases to the Ras guanine nucleotide releasing protein
           Sos (son of sevenless), which converts Ras to the active
           GTP-bound state. GRAP2 plays an important role in T cell
           receptor (TCR) signaling by promoting the formation of
           the SLP-76:LAT complex, which couples the TCR to the Ras
           pathway. GRAP acts as a negative regulator of T cell
           receptor (TCR)-induced lymphocyte proliferation by
           downregulating the signaling to the Ras/ERK pathway. The
           N-terminal SH3 domain of GRB2 binds to Sos and
           Sos-derived proline-rich peptides. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 47.4 bits (113), Expect = 1e-07
 Identities = 19/51 (37%), Positives = 32/51 (62%), Gaps = 2/51 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDE-EHWWTAQNISGEVGSIPVPYV 163
           +AK+DF     D+L FKK  IL V++ ++  +W+ A+ + G+ G IP  Y+
Sbjct: 3   VAKHDFKATAEDELSFKKGSILKVLNMEDDPNWYKAE-LDGKEGLIPKNYI 52


>gnl|CDD|198230 cd10367, SH2_Src_Fgr, Src homology 2 (SH2) domain found in
          Gardner-Rasheed feline sarcoma viral (v-fgr) oncogene
          homolog, Fgr.  Fgr is a member of the Src non-receptor
          type tyrosine kinase family of proteins. The protein
          contains N-terminal sites for myristoylation and
          palmitoylation, a PTK domain, and SH2 and SH3 domains
          which are involved in mediating protein-protein
          interactions with phosphotyrosine-containing and
          proline-rich motifs, respectively. Fgr is expressed in
          B-cells and myeloid cells, localizes to plasma membrane
          ruffles, and functions as a negative regulator of cell
          migration and adhesion triggered by the beta-2 integrin
          signal transduction pathway. Multiple alternatively
          spliced variants, encoding the same protein, have been
          identified  Fgr has been shown to interact with
          Wiskott-Aldrich syndrome protein. Fgr has a unique
          N-terminal domain, an SH3 domain, an SH2 domain, a
          kinase domain and a regulatory tail, as do the other
          members of the family. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 101

 Score = 48.7 bits (116), Expect = 1e-07
 Identities = 24/62 (38%), Positives = 36/62 (58%), Gaps = 6/62 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          WYFG + R++A+  LLS  +  GAFL+R+S T  G Y L +++      + V HY I K+
Sbjct: 5  WYFGKIGRKDAERQLLSPGNPRGAFLIRESETTKGAYSLSIRDWDQNRGDHVKHYKIRKL 64

Query: 67 TN 68
            
Sbjct: 65 DT 66


>gnl|CDD|212796 cd11862, SH3_MPP, Src Homology 3 domain of Membrane Protein,
           Palmitoylated (or MAGUK p55 subfamily member) proteins. 
           The MPP/p55 subfamily of MAGUK (membrane-associated
           guanylate kinase) proteins includes at least eight
           vertebrate members (MPP1-7 and CASK), four Drosophila
           proteins (Stardust, Varicose, CASK and Skiff), and other
           similar proteins; they all contain one each of the core
           of three domains characteristic of MAGUK proteins: PDZ,
           SH3, and guanylate kinase (GuK). In addition, most
           members except for MPP1 contain N-terminal L27 domains
           and some also contain a Hook (Protein 4.1 Binding) motif
           in between the SH3 and GuK domains. CASK has an
           additional calmodulin-dependent kinase (CaMK)-like
           domain at the N-terminus. Members of this subfamily are
           scaffolding proteins that play important roles in
           regulating and establishing cell polarity, cell
           adhesion, and synaptic targeting and transmission, among
           others. The GuK domain in MAGUK proteins is
           enzymatically inactive; instead, the domain mediates
           protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 61

 Score = 47.6 bits (114), Expect = 1e-07
 Identities = 19/55 (34%), Positives = 31/55 (56%), Gaps = 10/55 (18%)

Query: 115 AKYDFDGNDPDDLP-------FKKNDILIVVSKDEEHWWTAQNI---SGEVGSIP 159
           A +D+D  +   +P       FKK DIL +V++D+ +WW A+ +   +G  G IP
Sbjct: 4   ALFDYDPEEDPLIPCKEAGLSFKKGDILQIVNQDDPNWWQARKVGDPNGRAGLIP 58


>gnl|CDD|212839 cd11906, SH3_BTK, Src Homology 3 domain of Bruton's tyrosine
           kinase.  BTK is a cytoplasmic (or nonreceptor) tyr
           kinase containing Src homology protein interaction
           domains (SH3, SH2) N-terminal to the catalytic tyr
           kinase domain. It also contains an N-terminal pleckstrin
           homology (PH) domain, which binds the products of PI3K
           and allows membrane recruitment and activation, and the
           Tec homology (TH) domain with proline-rich and
           zinc-binding regions. Btk is expressed in B-cells, and a
           variety of myeloid cells including mast cells,
           platelets, neutrophils, and dendrictic cells. It
           interacts with a variety of partners, from cytosolic
           proteins to nuclear transcription factors, suggesting a
           diversity of functions. Stimulation of a diverse array
           of cell surface receptors, including antigen engagement
           of the B-cell receptor (BCR), leads to PH-mediated
           membrane translocation of Btk and subsequent
           phosphorylation by Src kinase and activation. Btk plays
           an important role in the life cycle of B-cells including
           their development, differentiation, proliferation,
           survival, and apoptosis. Mutations in Btk cause the
           primary immunodeficiency disease, X-linked
           agammaglobulinaemia (XLA) in humans. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 47.1 bits (112), Expect = 1e-07
 Identities = 17/52 (32%), Positives = 29/52 (55%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           KV+A YD+   +  DL  +K +  +++ +    WW A++ +G  G IP  YV
Sbjct: 2   KVVALYDYTPMNAQDLQLRKGEEYVILEESNLPWWRARDKNGREGYIPSNYV 53


>gnl|CDD|212760 cd11826, SH3_Abi, Src homology 3 domain of Abl Interactor proteins.
            Abl interactor (Abi) proteins are adaptor proteins
           serving as binding partners and substrates of Abl
           tyrosine kinases. They are involved in regulating actin
           cytoskeletal reorganization and play important roles in
           membrane-ruffling, endocytosis, cell motility, and cell
           migration. They localize to sites of actin
           polymerization in epithelial adherens junction and
           immune synapses, as well as to the leading edge of
           lamellipodia. Vertebrates contain two Abi proteins, Abi1
           and Abi2. Abi1 displays a wide expression pattern while
           Abi2 is highly expressed in the eye and brain. Abi
           proteins contain a homeobox homology domain, a
           proline-rich region, and a SH3 domain. The SH3 domain of
           Abi binds to a PxxP motif in Abl. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 46.9 bits (112), Expect = 1e-07
 Identities = 25/47 (53%), Positives = 29/47 (61%), Gaps = 5/47 (10%)

Query: 219 YDKTALK-----LEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           YD TA K      + GDII VTK N +G +EG LNG TG FP  +VE
Sbjct: 6   YDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYVE 52



 Score = 41.2 bits (97), Expect = 2e-05
 Identities = 18/53 (33%), Positives = 32/53 (60%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           KV+A YD+  +  D+L F++ DI+ V  K+++ W+    ++G  G  P  YV+
Sbjct: 1   KVVALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGV-LNGVTGLFPGNYVE 52


>gnl|CDD|212757 cd11823, SH3_Nostrin, Src homology 3 domain of Nitric Oxide
           Synthase TRaffic INducer.  Nostrin is expressed in
           endothelial and epithelial cells and is involved in the
           regulation, trafficking and targeting of endothelial NOS
           (eNOS). It facilitates the endocytosis of eNOS by
           coordinating the functions of dynamin and the
           Wiskott-Aldrich syndrome protein (WASP). Increased
           expression of Nostrin may be correlated to preeclampsia.
           Nostrin contains an N-terminal F-BAR domain and a
           C-terminal SH3 domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 47.0 bits (112), Expect = 1e-07
 Identities = 23/45 (51%), Positives = 29/45 (64%), Gaps = 2/45 (4%)

Query: 216 PNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
            N  D+  L L+ GDII+V +   +G W GELNGK G FP T+VE
Sbjct: 10  ANREDE--LSLQPGDIIEVHEKQDDGWWLGELNGKKGIFPATYVE 52



 Score = 44.3 bits (105), Expect = 1e-06
 Identities = 16/50 (32%), Positives = 26/50 (52%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A Y +  N  D+L  +  DI+ V  K ++ WW    ++G+ G  P  YV+
Sbjct: 4   ALYSYTANREDELSLQPGDIIEVHEKQDDGWWLG-ELNGKKGIFPATYVE 52


>gnl|CDD|212720 cd11786, SH3_SH3RF_1, First Src Homology 3 domain of SH3 domain
           containing ring finger proteins.  This model represents
           the first SH3 domain of SH3RF1 (or POSH), SH3RF2 (or
           POSHER), SH3RF3 (POSH2), and similar domains. Members of
           this family are scaffold proteins that function as E3
           ubiquitin-protein ligases. They all contain an
           N-terminal RING finger domain and multiple SH3 domains;
           SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has
           three. SH3RF1 plays a role in calcium homeostasis
           through the control of the ubiquitin domain protein
           Herp. It may also have a role in regulating death
           receptor mediated and JNK mediated apoptosis. SH3RF3
           interacts with p21-activated kinase 2 (PAK2) and
           GTP-loaded Rac1. It may play a role in regulating JNK
           mediated apoptosis in certain conditions. SH3RF2 acts as
           an anti-apoptotic regulator of the JNK pathway by
           binding to and promoting the degradation of SH3RF1. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 47.0 bits (112), Expect = 1e-07
 Identities = 19/50 (38%), Positives = 33/50 (66%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A Y+++G +P DL FKK DI+++  + +E+W+  +  +G+ G  P  YVQ
Sbjct: 4   ALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGE-CNGKQGFFPASYVQ 52



 Score = 33.1 bits (76), Expect = 0.011
 Identities = 16/38 (42%), Positives = 23/38 (60%), Gaps = 2/38 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           L  + GDII + +  I+  W  GE NGK G FP ++V+
Sbjct: 16  LSFKKGDII-LLRKRIDENWYHGECNGKQGFFPASYVQ 52


>gnl|CDD|198178 cd09923, SH2_SOCS_family, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) family.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7). In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 81

 Score = 47.6 bits (114), Expect = 2e-07
 Identities = 19/41 (46%), Positives = 25/41 (60%), Gaps = 3/41 (7%)

Query: 12 SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCV 52
           WY+G +TR EA+  LL+ K  G FLVRDS+     Y+  V
Sbjct: 1  GWYWGGITRYEAEE-LLAGKPEGTFLVRDSSD--SRYLFSV 38


>gnl|CDD|212928 cd11995, SH3_Intersectin1_5, Fifth Src homology 3 domain (or SH3E)
           of Intersectin-1.  Intersectin-1 (ITSN1) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN1 localizes in membranous organelles, CCPs, the
           Golgi complex, and may be involved in the cell membrane
           trafficking system. It exists in alternatively spliced
           short and long isoforms. The short isoform contains two
           Eps15 homology domains (EH1 and EH2), a coiled-coil
           region and five SH3 domains (SH3A-E), while the long
           isoform, in addition, contains RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin homology (PH) and C2
           domains. The fifth SH3 domain (or SH3E) of ITSN1 has
           been shown to bind many protein partners including
           SGIP1, Sos1, dynamin1/2, CIN85, c-Cbl, SHIP2, N-WASP,
           and synaptojanin-1, among others. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 54

 Score = 46.5 bits (110), Expect = 2e-07
 Identities = 19/53 (35%), Positives = 33/53 (62%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +VI  YD+   + D+L F K  I+ V++K++  WW  + ++G+VG  P  YV+
Sbjct: 2   QVIGMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGE-LNGQVGLFPSNYVK 53



 Score = 31.1 bits (70), Expect = 0.076
 Identities = 20/53 (37%), Positives = 25/53 (47%), Gaps = 5/53 (9%)

Query: 214 RVPNAYDKTA-----LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEF 261
           +V   YD TA     L    G II V        W+GELNG+ G FP  +V+ 
Sbjct: 2   QVIGMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGELNGQVGLFPSNYVKL 54


>gnl|CDD|212789 cd11855, SH3_Sho1p, Src homology 3 domain of High osmolarity
           signaling protein Sho1p.  Sho1p (or Sho1), also called
           SSU81 (Suppressor of SUA8-1 mutation), is a yeast
           membrane protein that regulates adaptation to high salt
           conditions by activating the HOG (high-osmolarity
           glycerol) pathway. High salt concentrations lead to the
           localization to the membrane of the MAPKK Pbs2, which is
           then activated by the MAPKK Ste11 and in turn, activates
           the MAPK Hog1. Pbs2 is localized to the membrane though
           the interaction of its PxxP motif with the SH3 domain of
           Sho1p. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 46.3 bits (110), Expect = 3e-07
 Identities = 21/56 (37%), Positives = 31/56 (55%), Gaps = 5/56 (8%)

Query: 112 KVIAKYDFDGN--DPDDLPFKKNDILIVVSKDEE-HWWTAQNISGEVGSIPVPYVQ 164
           +  A Y +D +  DP++L F+K +IL V   D    WW A+  +GE G  P  Y+Q
Sbjct: 1   RARALYPYDASPDDPNELSFEKGEILEV--SDTSGKWWQARKSNGETGICPSNYLQ 54


>gnl|CDD|198229 cd10366, SH2_Src_Yes, Src homology 2 (SH2) domain found in Yes.
          Yes is a member of the Src non-receptor type tyrosine
          kinase family of proteins. Yes is the cellular homolog
          of the Yamaguchi sarcoma virus oncogene. In humans it
          is encoded by the YES1 gene which maps to chromosome 18
          and is in close proximity to thymidylate synthase. A
          corresponding Yes pseudogene has been found on
          chromosome 22. YES1 has been shown to interact with
          Janus kinase 2, CTNND1,RPL10, and Occludin. Yes1 has a
          unique N-terminal domain, an SH3 domain, an SH2 domain,
          a kinase domain and a regulatory tail, as do the other
          members of the family. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 101

 Score = 47.7 bits (113), Expect = 3e-07
 Identities = 31/89 (34%), Positives = 44/89 (49%), Gaps = 9/89 (10%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          WYFG M R++A+ +LL+  +  G FLVR+S T  G Y L +++      + V HY I K+
Sbjct: 5  WYFGKMGRKDAERLLLNPGNQRGIFLVRESETTKGAYSLSIRDWDEVRGDNVKHYKIRKL 64

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
           N      Y      F  L  L+  Y  H
Sbjct: 65 DNGGY---YITTRAQFDTLQKLVKHYTEH 90


>gnl|CDD|198211 cd10348, SH2_Cterm_shark_like, C-terminal Src homology 2 (SH2)
          domain found in SH2 domains, ANK, and kinase domain
          (shark) proteins.  These non-receptor protein-tyrosine
          kinases contain two SH2 domains, five ankyrin
          (ANK)-like repeats, and a potential tyrosine
          phosphorylation site in its carboxyl-terminal tail
          which resembles the phosphorylation site in members of
          the src family. Like, mammalian non-receptor
          protein-tyrosine kinases, ZAP-70 and syk proteins, they
          do not have SH3 domains. However, the presence of ANK
          makes these unique among protein-tyrosine kinases. Both
          tyrosine kinases and ANK repeats have been shown to
          transduce developmental signals, and SH2 domains are
          known to participate intimately in tyrosine kinase
          signaling. These tyrosine kinases are believed to be
          involved in epithelial cell polarity. The members of
          this family include the shark (SH2 domains, ANK, and
          kinase domain) gene in Drosophila and yellow fever
          mosquitos, as well as the hydra protein HTK16.
          Drosophila Shark is proposed to transduce
          intracellularly the Crumbs, a protein necessary for
          proper organization of ectodermal epithelia,
          intercellular signal. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 86

 Score = 47.0 bits (112), Expect = 3e-07
 Identities = 28/82 (34%), Positives = 36/82 (43%), Gaps = 6/82 (7%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          W  G + R EA  IL  + D +G+FLVR S    G YVL +   N V H+ I        
Sbjct: 2  WLHGALDRNEAVEILKQKADADGSFLVRYSRRRPGGYVLTLVYENHVYHFEIQN----RD 57

Query: 72 QTCYKIGD-KTFSDLPSLLAFY 92
             + I D   F  L  L+  Y
Sbjct: 58 DKWFYIDDGPYFESLEHLIEHY 79


>gnl|CDD|198216 cd10353, SH2_Nterm_RasGAP, N-terminal Src homology 2 (SH2) domain
          found in Ras GTPase-activating protein 1 (GAP).  RasGAP
          is part of the GAP1 family of GTPase-activating
          proteins. The protein is located in the cytoplasm and
          stimulates the GTPase activity of normal RAS p21, but
          not its oncogenic counterpart. Acting as a suppressor
          of RAS function, the protein enhances the weak
          intrinsic GTPase activity of RAS proteins resulting in
          RAS inactivation, thereby allowing control of cellular
          proliferation and differentiation. Mutations leading to
          changes in the binding sites of either protein are
          associated with basal cell carcinomas. Alternative
          splicing results in two isoforms. The shorter isoform
          which lacks the N-terminal hydrophobic region, has the
          same activity, and is expressed in placental tissues.
          In general the longer isoform contains 2 SH2 domains, a
          SH3 domain, a pleckstrin homology (PH) domain, and a
          calcium-dependent phospholipid-binding C2 domain. The
          C-terminus contains the catalytic domain of RasGap
          which catalyzes the activation of Ras by hydrolyzing
          GTP-bound active Ras into an inactive GDP-bound form of
          Ras. This model contains the N-terminal SH2 domain. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 103

 Score = 47.5 bits (113), Expect = 3e-07
 Identities = 25/82 (30%), Positives = 40/82 (48%), Gaps = 5/82 (6%)

Query: 11 NSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
          N WY G + R  A+  L      G++L+R+S+   G++VL       V+H+ I  +    
Sbjct: 19 NQWYHGRLDRTIAEERLRQAGKLGSYLIRESDRRPGSFVLSFLSRTGVNHFRIIAMCGD- 77

Query: 71 QQTCYKIGDKTFSDLPSLLAFY 92
              Y IG + FS L  L+ +Y
Sbjct: 78 ----YYIGGRRFSSLSDLIGYY 95


>gnl|CDD|212942 cd12009, SH3_Blk, Src homology 3 domain of Blk Protein Tyrosine
           Kinase.  Blk is a member of the Src subfamily of
           proteins, which are cytoplasmic (or non-receptor) PTKs.
           It is expressed specifically in B-cells and is involved
           in pre-BCR (B-cell receptor) signaling. Src kinases
           contain an N-terminal SH4 domain with a myristoylation
           site, followed by SH3 and SH2 domains, a tyr kinase
           domain, and a regulatory C-terminal region containing a
           conserved tyr. They are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). The SH3 domain of Src kinases
           contributes to substrate recruitment by binding adaptor
           proteins/substrates, and regulation of kinase activity
           through an intramolecular interaction. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 54

 Score = 46.0 bits (109), Expect = 4e-07
 Identities = 23/52 (44%), Positives = 33/52 (63%), Gaps = 2/52 (3%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYV 163
           VIA+YDF  ++  DL  KK + L V+  D E WW A+++ +G+ G IP  YV
Sbjct: 2   VIAQYDFVPSNERDLQLKKGEKLQVLKSDGE-WWLAKSLTTGKEGYIPSNYV 52


>gnl|CDD|212758 cd11824, SH3_PSTPIP1, Src homology 3 domain of
           Proline-Serine-Threonine Phosphatase-Interacting Protein
           1.  PSTPIP1, also called CD2 Binding Protein 1 (CD2BP1),
           is mainly expressed in hematopoietic cells. It is a
           binding partner of the cell surface receptor CD2 and
           PTP-PEST, a tyrosine phosphatase which functions in cell
           motility and Rac1 regulation. It also plays a role in
           the activation of the Wiskott-Aldrich syndrome protein
           (WASP), which couples actin rearrangement and T cell
           activation. Mutations in the gene encoding PSTPIP1 cause
           the autoinflammatory disorder known as PAPA (pyogenic
           sterile arthritis, pyoderma gangrenosum, and acne)
           syndrome. PSTPIP1 contains an N-terminal F-BAR domain,
           PEST motifs, and a C-terminal SH3 domain. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 45.8 bits (109), Expect = 4e-07
 Identities = 18/54 (33%), Positives = 31/54 (57%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           K    YD+   + D+L   K D++ V+ K E+ WWT +  +G+ G +P  Y++K
Sbjct: 1   KYSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTVER-NGQKGLVPGTYLEK 53



 Score = 31.6 bits (72), Expect = 0.051
 Identities = 14/44 (31%), Positives = 23/44 (52%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
            A +   L +  GD++ V +   +G W  E NG+ G  P T++E
Sbjct: 9   TAQEDDELSISKGDVVAVIEKGEDGWWTVERNGQKGLVPGTYLE 52


>gnl|CDD|198203 cd10340, SH2_N-SH2_SHP_like, N-terminal Src homology 2 (N-SH2)
          domain found in SH2 domain Phosphatases (SHP) proteins.
           The SH2 domain phosphatases (SHP-1, SHP-2/Syp,
          Drosophila corkscrew (csw), and Caenorhabditis elegans
          Protein Tyrosine Phosphatase (Ptp-2)) are cytoplasmic
          signaling enzymes. They are both targeted and regulated
          by interactions of their SH2 domains with
          phosphotyrosine docking sites. These proteins contain
          two SH2 domains (N-SH2, C-SH2) followed by a tyrosine
          phosphatase (PTP) domain, and a C-terminal extension.
          Shp1 and Shp2 have two tyrosyl phosphorylation sites in
          their C-tails, which are phosphorylated differentially
          by receptor and nonreceptor PTKs. Csw retains the
          proximal tyrosine and Ptp-2 lacks both sites.
          Shp-binding proteins include receptors, scaffolding
          adapters, and inhibitory receptors. Some of these bind
          both Shp1 and Shp2 while others bind only one. Most
          proteins that bind a Shp SH2 domain contain one or more
          immuno-receptor tyrosine-based inhibitory motifs
          (ITIMs): [IVL]xpYxx[IVL].  Shp1 N-SH2 domain blocks the
          catalytic domain and keeps the enzyme in the inactive
          conformation, and is thus believed to regulate the
          phosphatase activity of SHP-1. Its C-SH2 domain is
          thought to be involved in searching for phosphotyrosine
          activators. The SHP2 N-SH2 domain is a conformational
          switch; it either binds and inhibits the phosphatase,
          or it binds phosphoproteins and activates the enzyme.
          The C-SH2 domain contributes binding energy and
          specificity, but it does not have a direct role in
          activation. Csw SH2 domain function is essential, but
          either SH2 domain can fulfill this requirement. The
          role of the csw SH2 domains during Sevenless receptor
          tyrosine kinase (SEV) signaling is to bind Daughter of
          Sevenless rather than activated SEV.  Ptp-2 acts in
          oocytes downstream of sheath/oocyte gap junctions to
          promote major sperm protein (MSP)-induced MAP Kinase
          (MPK-1) phosphorylation. Ptp-2 functions in the oocyte
          cytoplasm, not at the cell surface to inhibit multiple
          RasGAPs, resulting in sustained Ras activation. It is
          thought that MSP triggers PTP-2/Ras activation and ROS
          production to stimulate MPK-1 activity essential for
          oocyte maturation and that secreted MSP domains and
          Cu/Zn superoxide dismutases function antagonistically
          to control ROS and MAPK signaling. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 99

 Score = 47.0 bits (112), Expect = 4e-07
 Identities = 24/81 (29%), Positives = 44/81 (54%), Gaps = 6/81 (7%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          W+  +++  EA+ +L +   +G+FL R S +  G++ L V+  ++V+H    KI NT   
Sbjct: 2  WFHPVISGIEAENLLKTRGVDGSFLARPSKSNPGDFTLSVRRGDEVTHI---KIQNTGD- 57

Query: 73 TCYK-IGDKTFSDLPSLLAFY 92
            Y   G + F+ L  L+ +Y
Sbjct: 58 -YYDLYGGEKFATLSELVQYY 77


>gnl|CDD|212756 cd11822, SH3_SASH_like, Src homology 3 domain of SAM And SH3 Domain
           Containing Proteins.  This subfamily, also called the
           SLY family, is composed of SAM And SH3 Domain Containing
           Protein 1 (SASH1), SASH2, SASH3, and similar proteins.
           These are adaptor proteins containing a central
           conserved region with a bipartite nuclear localization
           signal (NLS) as wells as SAM (sterile alpha motif) and
           SH3 domains. SASH1 is a potential tumor suppressor in
           breast and colon cancer. It is widely expressed in
           normal tissues (except lymphocytes and dendritic cells)
           and is localized in the nucleus and the cytoplasm. SASH1
           interacts with the oncoprotein cortactin and is
           important in cell migration and adhesion. SASH2 (also
           called SAMSN-1, SLY2, HACS1 or NASH1) and SASH3 (also
           called SLY/SLY1) are expressed mainly in hematopoietic
           cells, although SASH2 is also found in endothelial cells
           as well as myeloid leukemias and myeloma. SASH2 was
           found to be differentially expressed in malignant
           haematopoietic cells and in colorectal tumors, and is a
           potential tumor suppressor in lung cancer. SASH3 is
           essential in the full activation of adaptive immunity
           and is involved in the signaling of T cell receptors.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 45.7 bits (108), Expect = 4e-07
 Identities = 21/51 (41%), Positives = 28/51 (54%)

Query: 208 ARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTH 258
           A+V     P+ YD  +LKL+ GDII +      G W G LN K G+F F +
Sbjct: 2   AKVHTDFTPSPYDTDSLKLKKGDIIDIINKPPMGIWTGMLNNKVGNFKFIY 52


>gnl|CDD|198264 cd10401, SH2_C-SH2_Syk_like, C-terminal Src homology 2 (SH2)
          domain found in Spleen tyrosine kinase (Syk) proteins. 
          ZAP-70 and Syk comprise a family of hematopoietic cell
          specific protein tyrosine kinases (PTKs) that are
          required for antigen and antibody receptor function.
          ZAP-70 is expressed in T and natural killer (NK) cells 
          and Syk is expressed in B cells, mast cells,
          polymorphonuclear leukocytes, platelets, macrophages,
          and immature T cells. They are required for the proper
          development of T and B cells, immune receptors, and
          activating NK cells. They consist of two N-terminal Src
          homology 2 (SH2) domains and a C-terminal kinase domain
          separated from the SH2 domains by a linker or hinge
          region. Phosphorylation of both tyrosine residues
          within the Immunoreceptor Tyrosine-based Activation
          Motifs (ITAM; consensus sequence Yxx[LI]x(7,8)Yxx[LI])
          by the Src-family PTKs is required for efficient
          interaction of ZAP-70 and Syk with the receptor
          subunits and for receptor function. ZAP-70 forms two
          phosphotyrosine binding pockets, one of which is shared
          by both SH2 domains.  In Syk the two SH2 domains do not
          form such a phosphotyrosine-binding site.  The SH2
          domains here are believed to function independently. In
          addition, the two SH2 domains of Syk display
          flexibility in their relative orientation, allowing Syk
          to accommodate a greater variety of spacing sequences
          between the ITAM phosphotyrosines and singly
          phosphorylated non-classical ITAM ligands. This model
          contains the C-terminus SH2 domains of Syk. In general
          SH2 domains are involved in signal transduction.  They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 99

 Score = 46.8 bits (111), Expect = 5e-07
 Identities = 25/56 (44%), Positives = 37/56 (66%), Gaps = 6/56 (10%)

Query: 13 WYFGMMTRQEAQAILLS-EKDNGAFLV--RDSNTILGNYVLCVKENNKVSHYIINK 65
          W+ G ++R+E++ ILL   K NG FL+  RD+N   G+Y LC+  + KV HY I+K
Sbjct: 5  WFHGKISREESEQILLIGSKTNGKFLIRERDNN---GSYALCLLHDGKVLHYRIDK 57


>gnl|CDD|212816 cd11883, SH3_Sdc25, Src Homology 3 domain of Sdc25/Cdc25 guanine
           nucleotide exchange factors.  This subfamily is composed
           of the Saccharomyces cerevisiae guanine nucleotide
           exchange factors (GEFs) Sdc25 and Cdc25, and similar
           proteins. These GEFs regulate Ras by stimulating the
           GDP/GTP exchange on Ras. Cdc25 is involved in the
           Ras/PKA pathway that plays an important role in the
           regulation of metabolism, stress responses, and
           proliferation, depending on available nutrients and
           conditions. Proteins in this subfamily contain an
           N-terminal SH3 domain as well as REM (Ras exchanger
           motif) and RasGEF domains at the C-terminus. SH3 domains
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs; they play a
           role in the regulation of enzymes by intramolecular
           interactions, changing the subcellular localization of
           signal pathway components and mediate multiprotein
           complex assemblies.
          Length = 55

 Score = 45.4 bits (108), Expect = 5e-07
 Identities = 15/34 (44%), Positives = 20/34 (58%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWW 146
           V+A YDF     + L FK  DI+ V++KD   WW
Sbjct: 2   VVALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWW 35



 Score = 30.3 bits (69), Expect = 0.11
 Identities = 14/44 (31%), Positives = 19/44 (43%), Gaps = 5/44 (11%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELNG-----KTGHFP 255
               K  L  + GDII V   + +G W+G +       K G FP
Sbjct: 9   TPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKVKRGWFP 52


>gnl|CDD|212929 cd11996, SH3_Intersectin2_5, Fifth Src homology 3 domain (or SH3E)
           of Intersectin-2.  Intersectin-2 (ITSN2) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN2 also functions as a specific GEF for Cdc42
           activation in epithelial morphogenesis, and is required
           in mitotic spindle orientation. It exists in
           alternatively spliced short and long isoforms. The short
           isoform contains two Eps15 homology domains (EH1 and
           EH2), a coiled-coil region and five SH3 domains
           (SH3A-E), while the long isoform, in addition, contains
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           homology (PH) and C2 domains. The fifth SH3 domain (or
           SH3E) of ITSN2 is expected to bind protein partners,
           similar to ITSN1 which has been shown to bind many
           protein partners including SGIP1, Sos1, dynamin1/2,
           CIN85, c-Cbl, SHIP2, N-WASP, and synaptojanin-1, among
           others. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 45.4 bits (107), Expect = 6e-07
 Identities = 21/53 (39%), Positives = 33/53 (62%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +VIA YD+  N+ D+L F K  ++ V++KD+  WW  + I+G  G  P  YV+
Sbjct: 2   QVIAMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGE-INGVTGLFPSNYVK 53



 Score = 30.3 bits (68), Expect = 0.14
 Identities = 18/47 (38%), Positives = 24/47 (51%), Gaps = 5/47 (10%)

Query: 219 YDKTA-----LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           YD TA     L    G +I V   +    W+GE+NG TG FP  +V+
Sbjct: 7   YDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVTGLFPSNYVK 53


>gnl|CDD|212746 cd11812, SH3_AHI-1, Src Homology 3 domain of Abelson helper
           integration site-1 (AHI-1).  AHI-1, also called
           Jouberin, is expressed in high levels in the brain,
           gonad tissues, and skeletal muscle. It is an adaptor
           protein that interacts with the small GTPase Rab8a and
           regulates it distribution and function, affecting cilium
           formation and vesicle transport. Mutations in the AHI-1
           gene can cause Joubert syndrome, a disorder
           characterized by brainstem malformations, cerebellar
           aplasia/hypoplasia, and retinal dystrophy. AHI-1
           variation is also associated with susceptibility to
           schizophrenia and type 2 diabetes mellitus progression.
           AHI-1 contains WD40 and SH3 domains. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 45.2 bits (107), Expect = 6e-07
 Identities = 19/51 (37%), Positives = 30/51 (58%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           V+A YD+  N  D+L   + DI+ V+ KD ++WW    ++G+ G  P  YV
Sbjct: 2   VVALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFGSLVNGQQGYFPANYV 52


>gnl|CDD|199830 cd10349, SH2_SH2D2A_SH2D7, Src homology 2 domain found in the SH2
          domain containing protein 2A and 7 (SH2D2A and SH2D7). 
          SH2D2A and SH7 both contain a single SH2 domain. In
          general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 77

 Score = 46.0 bits (109), Expect = 6e-07
 Identities = 22/82 (26%), Positives = 42/82 (51%), Gaps = 8/82 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          W+ G +TR+EA+  LL  K  G +LVR S + +  +VL  +      H+++ ++ +    
Sbjct: 2  WFHGFITRREAER-LLEPKPQGCYLVRFSESAVT-FVLSYRSRTCCRHFLLAQLRD---- 55

Query: 73 TCYKI-GDKT-FSDLPSLLAFY 92
            + + G+ +  + L  LL  Y
Sbjct: 56 GRHVVLGEDSAHARLQDLLLHY 77


>gnl|CDD|198272 cd10409, SH2_Nck2, Src homology 2 (SH2) domain found in Nck.  Nck
          proteins are adaptors that modulate actin cytoskeleton
          dynamics by linking proline-rich effector molecules to
          tyrosine kinases or phosphorylated signaling
          intermediates.  There are two members known in this
          family: Nck1 (Nckalpha) and Nck2 (Nckbeta and Growth
          factor receptor-bound protein 4 (Grb4)).  They are
          characterized by having 3 SH3 domains and a C-terminal
          SH2 domain. Nck1 and Nck2 have overlapping functions as
          determined by gene knockouts. Both bind receptor
          tyrosine kinases and other tyrosine-phosphorylated
          proteins through their SH2 domains. In addition they
          also bind distinct targets.  Neuronal signaling
          proteins: EphrinB1, EphrinB2, and Disabled-1 (Dab-1)
          all bind to Nck-2 exclusively. And in the case of
          PDGFR, Tyr(P)751 binds to  Nck1 while Tyr(P)1009 binds
          to Nck2. Nck1 and Nck2 have a role in the infection
          process of enteropathogenic Escherichia coli (EPEC).
          Their SH3 domains are involved in recruiting and
          activating the N-WASP/Arp2/3 complex inducing actin
          polymerization resulting in the production of
          pedestals, dynamic bacteria-presenting protrusions of
          the plasma membrane. A similar thing occurs in the
          vaccinia virus where motile plasma membrane projections
          are formed beneath the virus.  Recently it has been
          shown that the SH2 domains of both Nck1 and Nck2 bind
          the G-protein coupled receptor kinase-interacting
          protein 1 (GIT1) in a phosphorylation-dependent manner.
          In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 98

 Score = 46.2 bits (109), Expect = 7e-07
 Identities = 24/81 (29%), Positives = 41/81 (50%), Gaps = 5/81 (6%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY+G +TR +A+  L      G FL+RDS +   ++ + +K   K  H+ +  + N    
Sbjct: 3  WYYGNVTRHQAECALNERGVEGDFLIRDSESSPSDFSVSLKAVGKNKHFKVQLVDNV--- 59

Query: 73 TCYKIGDKTFSDLPSLLAFYK 93
            Y IG + F+ +  L+  YK
Sbjct: 60 --YCIGQRRFNSMDELVEHYK 78


>gnl|CDD|212840 cd11907, SH3_TXK, Src Homology 3 domain of TXK, also called Resting
           lymphocyte kinase (Rlk).  TXK is a cytoplasmic (or
           nonreceptor) tyr kinase containing Src homology protein
           interaction domains (SH3, SH2) N-terminal to the
           catalytic tyr kinase domain. It also contains an
           N-terminal cysteine-rich region. Rlk is expressed in
           T-cells and mast cell lines, and is a key component of
           T-cell receptor (TCR) signaling. It is important in
           TCR-stimulated proliferation, IL-2 production and
           phospholipase C-gamma1 activation. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 44.9 bits (106), Expect = 8e-07
 Identities = 18/52 (34%), Positives = 30/52 (57%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +V A YDF   +P +L  K+ +  +++ + + HWW A++  G  G IP  YV
Sbjct: 2   QVKALYDFLPREPSNLALKRAEEYLILEQYDPHWWKARDRYGNEGLIPSNYV 53


>gnl|CDD|198268 cd10405, SH2_Vav1, Src homology 2 (SH2) domain found in the Vav1
          proteins.  Proto-oncogene vav is a member of the Dbl
          family of guanine nucleotide exchange factors (GEF) for
          the Rho family of GTP binding proteins.  All vavs are
          activated by tyrosine phosphorylation leading to their
          activation. There are three Vav mammalian family
          members: Vav1 which is expressed in the hematopoietic
          system, and Vav2 and Vav3 are more ubiquitously
          expressed. Vav1 plays a role in T-cell and B-cell
          development and activation.  It has been identified as
          the specific binding partner of Nef proteins from
          HIV-1, resulting in morphological changes, cytoskeletal
          rearrangements, and the JNK/SAPK signaling cascade,
          leading to increased levels of viral transcription and
          replication. Vav1 has been shown to interact with Ku70,
          PLCG1, Lymphocyte cytosolic protein 2, Janus kinase 2,
          SIAH2, S100B, Abl gene, ARHGDIB, SHB, PIK3R1, PRKCQ,
          Grb2, MAPK1, Syk, Linker of activated T cells, Cbl gene
          and EZH2. Vav proteins are involved in several
          processes that require cytoskeletal reorganization,
          such as the formation of the immunological synapse
          (IS), phagocytosis, platelet aggregation, spreading,
          and transformation.  Vavs function as guanine
          nucleotide exchange factors (GEFs) for the Rho/Rac
          family of GTPases. Vav family members have several
          conserved motifs/domains including: a leucine-rich
          region, a leucine-zipper, a calponin homology (CH)
          domain, an acidic domain, a Dbl-homology (DH) domain, a
          pleckstrin homology (PH) domain, a cysteine-rich
          domain, 2 SH3 domains, a proline-rich region, and a SH2
          domain.  Vavs are the only known Rho GEFs that have
          both the DH/PH motifs and SH2/SH3 domains in the same
          protein. The leucine-rich helix-loop-helix (HLH) domain
          is thought to be involved in protein heterodimerization
          with other HLH proteins and it may function as a
          negative regulator by forming inactive heterodimers.
          The CH domain  is usually involved in the association
          with filamentous actin, but in Vav it controls NFAT
          stimulation, Ca2+ mobilization, and its transforming
          activity. Acidic domains are involved in
          protein-protein interactions and contain regulatory
          tyrosines. The DH domain is a GDP-GTP exchange factor
          on Rho/Rac GTPases. The PH domain in involved in
          interactions with GTP-binding proteins, lipids and/or
          phosphorylated serine/threonine residues.  The SH3
          domain is involved in localization of proteins to
          specific sites within the cell interacting with protein
          with proline-rich sequences. The SH2 domain mediates a
          high affinity interaction with tyrosine phosphorylated
          proteins. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 103

 Score = 46.2 bits (109), Expect = 9e-07
 Identities = 27/86 (31%), Positives = 41/86 (47%), Gaps = 7/86 (8%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G M R  A++IL +  D G +LVR        + + +K N +V H  I        +
Sbjct: 7  WYAGPMERAGAESILANRSD-GTYLVRQRVKDAAEFAISIKYNVEVKHIKI-----MTAE 60

Query: 73 TCYKIGD-KTFSDLPSLLAFYKVHYL 97
            Y+I + K F  L  L+ FY+ + L
Sbjct: 61 GLYRITEKKAFRGLTELVEFYQQNSL 86


>gnl|CDD|198277 cd10414, SH2_Grb14, Src homology 2 (SH2) domain found in the
          growth factor receptor bound, subclass 14 (Grb14)
          proteins.  The Grb family binds to the epidermal growth
          factor receptor (EGFR, erbB1) via their SH2 domains.
          Grb14 is part of the Grb7 family of proteins which also
          includes Grb7, and Grb14. They are composed of an
          N-terminal Proline-rich domain, a Ras Associating-like
          (RA) domain, a Pleckstrin Homology (PH) domain, a
          phosphotyrosine interaction region (PIR, BPS) and a
          C-terminal SH2 domain. The SH2 domains of Grb7, Grb10
          and Grb14 preferentially bind to a different RTK. Grb14
          binds to Fibroblast Growth Factor Receptor (FGFR) and
          weakly to the erbB2 receptor. In general SH2 domains
          are involved in signal transduction. They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 108

 Score = 46.1 bits (109), Expect = 1e-06
 Identities = 27/90 (30%), Positives = 46/90 (51%), Gaps = 2/90 (2%)

Query: 8  HDRNSWYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNKVSHY-IINK 65
          H    W+   ++R EAQ +++ +   +G FLVRDS +    +VL +    K+ H+ II  
Sbjct: 2  HRSQPWFHHKISRDEAQRLIIQQGLVDGVFLVRDSQSNPRTFVLSMSHGQKIKHFQIIPV 61

Query: 66 ITNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
            + E       G   F+DL  L+ FY+++
Sbjct: 62 EDDGELFHTLDDGHTRFTDLIQLVEFYQLN 91


>gnl|CDD|212706 cd11772, SH3_OSTF1, Src Homology 3 domain of metazoan osteoclast
           stimulating factor 1.  OSTF1, also named OSF or SH3P2,
           is a signaling protein containing SH3 and ankyrin-repeat
           domains. It acts through a Src-related pathway to
           enhance the formation of osteoclasts and bone
           resorption. It also acts as a negative regulator of cell
           motility. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 44.6 bits (106), Expect = 1e-06
 Identities = 19/49 (38%), Positives = 29/49 (59%), Gaps = 1/49 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           A YD++   PD+L F++ D+L +  K + +WW A    G+ G IP  YV
Sbjct: 4   ALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKAT-CGGKTGLIPSNYV 51



 Score = 29.6 bits (67), Expect = 0.22
 Identities = 12/37 (32%), Positives = 19/37 (51%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L  E GD++ ++  +    W+    GKTG  P  +VE
Sbjct: 16  LSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYVE 52


>gnl|CDD|212709 cd11775, SH3_Sla1p_3, Third Src Homology 3 domain of the fungal
           endocytic adaptor protein Sla1p.  Sla1p facilitates
           endocytosis by playing a role as an adaptor protein in
           coupling components of the actin cytoskeleton to the
           endocytic machinery. It interacts with Abp1p, Las17p and
           Pan1p, which are activator proteins of actin-related
           protein 2/3 (Arp2/3). Sla1p contains multiple domains
           including three SH3 domains, a SAM (sterile alpha motif)
           domain, and a Sla1 homology domain 1 (SHD1), which binds
           to the NPFXD motif that is found in many integral
           membrane proteins such as the Golgi-localized
           Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and
           Dnf1p. The third SH3 domain of Sla1p can bind ubiquitin
           while retaining the ability to bind proline-rich
           ligands; monoubiquitination of target proteins signals
           internalization and sorting through the endocytic
           pathway. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 44.6 bits (106), Expect = 1e-06
 Identities = 16/56 (28%), Positives = 31/56 (55%), Gaps = 2/56 (3%)

Query: 111 EKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH-WWTAQNIS-GEVGSIPVPYVQ 164
           ++    YDFD    D+L  K+ D++ ++   +   WW  +N+S G+ G +P  Y++
Sbjct: 1   KRGKVLYDFDAQSDDELTVKEGDVVYILDDKKSKDWWMVENVSTGKEGVVPASYIE 56


>gnl|CDD|198188 cd09934, SH2_Tec_family, Src homology 2 (SH2) domain found in
          Tec-like proteins.  The Tec protein tyrosine kinase is
          the founding member of a family that includes Btk, Itk,
          Bmx, and Txk. The members have a PH domain, a
          zinc-binding motif, a SH3 domain, a SH2 domain, and a
          protein kinase catalytic domain. Btk is involved in
          B-cell receptor signaling with mutations in Btk
          responsible for X-linked agammaglobulinemia (XLA) in
          humans and X-linked immunodeficiency (xid) in mice. Itk
          is involved in T-cell receptor signaling. Tec is
          expressed in both T and B cells, and is thought to
          function in activated and effector T lymphocytes to
          induce the expression of genes regulated by NFAT
          transcription factors. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 45.9 bits (109), Expect = 1e-06
 Identities = 26/90 (28%), Positives = 48/90 (53%), Gaps = 10/90 (11%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCV----KENNKVSHYIIN 64
          ++  WY G M+RQ A+++L  E   G F+VR+S+T  G Y + +      +  V HY I 
Sbjct: 4  EKYEWYVGDMSRQRAESLLKQEDKEGCFVVRNSST-KGLYTVSLFTKVPGSPHVKHYHIK 62

Query: 65 KITNTEQQTCYKIGDK-TFSDLPSLLAFYK 93
          +  N   +  + + +K  F  +P L+ +++
Sbjct: 63 Q--NARSE--FYLAEKHCFETIPELINYHQ 88


>gnl|CDD|212909 cd11976, SH3_VAV1_2, C-terminal (or second) Src homology 3 domain
           of VAV1 protein.  VAV1 is expressed predominantly in the
           hematopoietic system and it plays an important role in
           the development and activation of B and T cells. It is
           activated by tyrosine phosphorylation to function as a
           guanine nucleotide exchange factor (GEF) for Rho GTPases
           following cell surface receptor activation, triggering
           various effects such as cytoskeletal reorganization,
           transcription regulation, cell cycle progression, and
           calcium mobilization. It also serves as a scaffold
           protein and has been shown to interact with Ku70, Socs1,
           Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76,
           and Syk, among others. VAV proteins contain several
           domains that enable their function: N-terminal calponin
           homology (CH), acidic, RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin Homology (PH), C1
           (zinc finger), SH2, and two SH3 domains. The C-terminal
           SH3 domain of Vav1 interacts with a wide variety of
           proteins including cytoskeletal regulators (zyxin),
           RNA-binding proteins (Sam68), transcriptional
           regulators, viral proteins, and dynamin 2. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 44.5 bits (105), Expect = 1e-06
 Identities = 20/44 (45%), Positives = 27/44 (61%), Gaps = 1/44 (2%)

Query: 218 AYDKTALKLEIGDIIKV-TKTNINGQWEGELNGKTGHFPFTHVE 260
           A D++ L L+ GDIIK+  K    G W GE+ G+ G FP  +VE
Sbjct: 10  ARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRVGWFPANYVE 53



 Score = 38.8 bits (90), Expect = 1e-04
 Identities = 18/51 (35%), Positives = 28/51 (54%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           A+YDF   D  +L  K+ DI+ +++K  +  W    I G VG  P  YV++
Sbjct: 4   ARYDFCARDRSELSLKEGDIIKILNKKGQQGWWRGEIYGRVGWFPANYVEE 54


>gnl|CDD|198276 cd10413, SH2_Grb7, Src homology 2 (SH2) domain found in the
          growth factor receptor bound, subclass 7 (Grb7)
          proteins.  The Grb family binds to the epidermal growth
          factor receptor (EGFR, erbB1) via their SH2 domains.
          Grb7 is part of the Grb7 family of proteins which also
          includes Grb10, and Grb14. They are composed of an
          N-terminal Proline-rich domain, a Ras Associating-like
          (RA) domain, a Pleckstrin Homology (PH) domain, a
          phosphotyrosine interaction region (PIR, BPS) and a
          C-terminal SH2 domain. The SH2 domains of Grb7, Grb10
          and Grb14 preferentially bind to a different RTK. Grb7
          binds strongly to the erbB2 receptor, unlike Grb10 and
          Grb14 which bind weakly to it. Grb7 family proteins are
          phosphorylated on serine/threonine as well as tyrosine
          residues. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 108

 Score = 45.7 bits (108), Expect = 1e-06
 Identities = 26/91 (28%), Positives = 48/91 (52%), Gaps = 4/91 (4%)

Query: 8  HDRNSWYFGMMTRQEAQAILLSEK-DNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKI 66
          H    W+ G ++R+E+Q ++  +   +G FLVR+S      +VL +    KV HY+I   
Sbjct: 2  HRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPS 61

Query: 67 TNTEQQTCYKI--GDKTFSDLPSLLAFYKVH 95
             E +  + +  G   F+DL  L+ F++++
Sbjct: 62 -EEEGRLYFSMDDGQTRFTDLLQLVEFHQLN 91


>gnl|CDD|212940 cd12007, SH3_Yes, Src homology 3 domain of Yes Protein Tyrosine
           Kinase.  Yes (or c-Yes) is a member of the Src subfamily
           of proteins, which are cytoplasmic (or non-receptor)
           PTKs. c-Yes kinase is the cellular homolog of the
           oncogenic protein (v-Yes) encoded by the Yamaguchi 73
           and Esh sarcoma viruses. It displays functional overlap
           with other Src subfamily members, particularly Src. It
           also shows some unique functions such as binding to
           occludins, transmembrane proteins that regulate
           extracellular interactions in tight junctions. Yes also
           associates with a number of proteins in different cell
           types that Src does not interact with, like JAK2 and
           gp130 in pre-adipocytes, and Pyk2 in treated pulmonary
           vein endothelial cells. Although the biological function
           of Yes remains unclear, it appears to have a role in
           regulating cell-cell interactions and vesicle
           trafficking in polarized cells. Src kinases contain an
           N-terminal SH4 domain with a myristoylation site,
           followed by SH3 and SH2 domains, a tyr kinase domain,
           and a regulatory C-terminal region containing a
           conserved tyr. They are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). The SH3 domain of Src kinases
           contributes to substrate recruitment by binding adaptor
           proteins/substrates, and regulation of kinase activity
           through an intramolecular interaction. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 58

 Score = 44.3 bits (104), Expect = 1e-06
 Identities = 19/51 (37%), Positives = 31/51 (60%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYV 163
           +A YD++    +DL FKK +   +++  E  WW A++I +G+ G IP  YV
Sbjct: 4   VALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGKNGYIPSNYV 54


>gnl|CDD|213014 cd12081, SH3_CASK, Src Homology 3 domain of
           Calcium/calmodulin-dependent Serine protein Kinase.
           CASK is a scaffolding protein that is highly expressed
           in the mammalian nervous system and plays roles in
           synaptic protein targeting, neural development, and gene
           expression regulation. CASK interacts with many
           different binding partners including parkin, neurexin,
           syndecans, calcium channel proteins, caskin, among
           others, to perform specific functions in different
           subcellular locations. Disruption of the CASK gene in
           mice results in neonatal lethality while mutations in
           the human gene have been associated with X-linked mental
           retardation. Drosophila CASK is associated with both
           pre- and postsynaptic membranes and is crucial in
           synaptic transmission and vesicle cycling. CASK contains
           an N-terminal calmodulin-dependent kinase (CaMK)-like
           domain, two L27 domains, followed by the core of three
           domains characteristic of MAGUK (membrane-associated
           guanylate kinase) proteins: PDZ, SH3, and guanylate
           kinase (GuK). In addition, it also contains the Hook
           (Protein 4.1 Binding) motif in between the SH3 and GuK
           domains. The GuK domain in MAGUK proteins is
           enzymatically inactive; instead, the domain mediates
           protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 62

 Score = 44.5 bits (105), Expect = 1e-06
 Identities = 20/59 (33%), Positives = 33/59 (55%), Gaps = 10/59 (16%)

Query: 113 VIAKYDFDGNDPDDLP-------FKKNDILIVVSKDEEHWWTAQ---NISGEVGSIPVP 161
           V A++++D    D +P       F+  DIL ++SKD+ +WW A+   + +G  G IP P
Sbjct: 2   VRAQFEYDPLKDDLIPCKQAGIRFRVGDILQIISKDDHNWWQAKLENSKNGTAGLIPSP 60


>gnl|CDD|212810 cd11877, SH3_PIX, Src Homology 3 domain of Pak Interactive eXchange
           factors.  PIX proteins are Rho guanine nucleotide
           exchange factors (GEFs), which activate small GTPases by
           exchanging bound GDP for free GTP. They act as GEFs for
           both Cdc42 and Rac 1, and have been implicated in cell
           motility, adhesion, neurite outgrowth, and cell
           polarity. Vertebrates contain two proteins from the PIX
           subfamily, alpha-PIX and beta-PIX. Alpha-PIX, also
           called ARHGEF6, is localized in dendritic spines where
           it regulates spine morphogenesis. Mutations in the
           ARHGEF6 gene cause X-linked intellectual disability in
           humans. Beta-PIX play roles in regulating neuroendocrine
           exocytosis, focal adhesion maturation, cell migration,
           synaptic vesicle localization, and insulin secretion.
           PIX proteins contain an N-terminal SH3 domain followed
           by RhoGEF (also called Dbl-homologous or DH) and
           Pleckstrin Homology (PH) domains, and a C-terminal
           leucine-zipper domain for dimerization. The SH3 domain
           of PIX binds to an atypical PxxxPR motif in
           p21-activated kinases (PAKs) with high affinity. The
           binding of PAKs to PIX facilitate the localization of
           PAKs to focal complexes and also localizes PAKs to PIX
           targets Cdc43 and Rac, leading to the activation of
           PAKs. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 44.2 bits (105), Expect = 1e-06
 Identities = 20/37 (54%), Positives = 24/37 (64%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L  + GDII VT+    G WEG LNGKTG FP  +V+
Sbjct: 16  LSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYVK 52



 Score = 43.5 bits (103), Expect = 2e-06
 Identities = 20/52 (38%), Positives = 29/52 (55%), Gaps = 1/52 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
            V AK++F+G + D+L F K DI+ V    E  WW    ++G+ G  P  YV
Sbjct: 1   LVRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEG-TLNGKTGWFPSNYV 51


>gnl|CDD|198227 cd10364, SH2_Src_Lyn, Src homology 2 (SH2) domain found in Lyn.
          Lyn is a member of the Src non-receptor type tyrosine
          kinase family of proteins and is expressed in the
          hematopoietic cells, in neural tissues, liver, and
          adipose tissue. There are two alternatively spliced
          forms of Lyn.  Lyn plays an inhibitory role in myeloid
          lineage proliferation. Following engagement of the B
          cell receptors, Lyn undergoes rapid phosphorylation and
          activation, triggering a cascade of signaling events
          mediated by Lyn phosphorylation of tyrosine residues
          within the immunoreceptor tyrosine-based activation
          motifs (ITAM) of the receptor proteins, and subsequent
          recruitment and activation of other kinases including
          Syk, phospholipase C2 (PLC2) and phosphatidyl
          inositol-3 kinase. These kinases play critical roles in
          proliferation, Ca2+ mobilization and cell
          differentiation. Lyn plays an essential role in the
          transmission of inhibitory signals through
          phosphorylation of tyrosine residues within the
          immunoreceptor tyrosine-based inhibitory motifs (ITIM)
          in regulatory proteins such as CD22, PIR-B and FC
          RIIb1. Their ITIM phosphorylation subsequently leads to
          recruitment and activation of phosphatases such as
          SHIP-1 and SHP-1 which further down modulate signaling
          pathways, attenuate cell activation and can mediate
          tolerance. Lyn also plays a role in the insulin
          signaling pathway. Activated Lyn phosphorylates insulin
          receptor substrate 1 (IRS1) leading to an increase in
          translocation of Glut-4 to the cell membrane and
          increased glucose utilization. It is the primary Src
          family member involved in signaling downstream of the B
          cell receptor. Lyn plays an unusual, 2-fold role in B
          cell receptor signaling; it is essential for initiation
          of signaling but is also later involved in negative
          regulation of the signal. Lyn has a unique N-terminal
          domain, an SH3 domain, an SH2 domain, a kinase domain
          and a regulatory tail, as do the other members of the
          family. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 45.4 bits (107), Expect = 1e-06
 Identities = 26/87 (29%), Positives = 48/87 (55%), Gaps = 9/87 (10%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          W+F  +TR++A+  LL+  ++ GAFL+R+S T+ G+Y L V++      + + HY I  +
Sbjct: 5  WFFKDITRKDAERQLLAPGNSAGAFLIRESETLKGSYSLSVRDYDPQHGDVIKHYKIRSL 64

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFYK 93
           N       +I   TF  +  ++  Y+
Sbjct: 65 DNGGYYISPRI---TFPCISDMIKHYQ 88


>gnl|CDD|212777 cd11843, SH3_PACSIN, Src homology 3 domain of Protein kinase C and
           Casein kinase Substrate in Neurons (PACSIN) proteins.
           PACSINs, also called Synaptic dynamin-associated
           proteins (Syndapins), act as regulators of cytoskeletal
           and membrane dynamics. They bind both dynamin and
           Wiskott-Aldrich syndrome protein (WASP), and may provide
           direct links between the actin cytoskeletal machinery
           through WASP and dynamin-dependent endocytosis.
           Vetebrates harbor three isoforms with distinct
           expression patterns and specific functions. PACSINs
           contain an N-terminal F-BAR domain and a C-terminal SH3
           domain. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 43.9 bits (104), Expect = 2e-06
 Identities = 20/52 (38%), Positives = 30/52 (57%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           V A YD++G + D+L FK  DIL  + +++E  W    + G VG  P  YV+
Sbjct: 2   VRALYDYEGQESDELSFKAGDILTKLEEEDEQGWCKGRLDGRVGLYPANYVE 53


>gnl|CDD|213018 cd12142, SH3_D21-like, Src Homology 3 domain of SH3
           domain-containing protein 21 (SH3D21) and similar
           proteins.  N-terminal SH3 domain of the uncharacterized
           protein SH3 domain-containing protein 21, and similar
           uncharacterized domains, it belongs to the CD2AP-like_3
           subfamily of proteins. The CD2AP-like_3 subfamily is
           composed of the third SH3 domain (SH3C) of CD2AP, CIN85
           (Cbl-interacting protein of 85 kDa), and similar
           domains. CD2AP and CIN85 are adaptor proteins that bind
           to protein partners and assemble complexes that have
           been implicated in T cell activation, kidney function,
           and apoptosis of neuronal cells. They also associate
           with endocytic proteins, actin cytoskeleton components,
           and other adaptor proteins involved in receptor tyrosine
           kinase (RTK) signaling. CD2AP and the main isoform of
           CIN85 contain three SH3 domains, a proline-rich region,
           and a C-terminal coiled-coil domain. All of these
           domains enable CD2AP and CIN85 to bind various protein
           partners and assemble complexes that have been
           implicated in many different functions. SH3C of both
           proteins have been shown to bind to ubiquitin. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 44.0 bits (104), Expect = 2e-06
 Identities = 22/47 (46%), Positives = 26/47 (55%), Gaps = 4/47 (8%)

Query: 216 PNAYDKTALKLEIGDIIKVTKTNI--NGQWEGELNGKTGHFPFTHVE 260
           P A D+ ALK   GD+I+V        G WEGELNG+ G FP   V 
Sbjct: 10  PVAPDELALK--KGDVIEVISKETEDEGWWEGELNGRRGFFPDNFVM 54



 Score = 29.7 bits (67), Expect = 0.19
 Identities = 17/49 (34%), Positives = 30/49 (61%), Gaps = 3/49 (6%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSK--DEEHWWTAQNISGEVGSIPVPYV 163
           +D++   PD+L  KK D++ V+SK  ++E WW  + ++G  G  P  +V
Sbjct: 6   FDYNPVAPDELALKKGDVIEVISKETEDEGWWEGE-LNGRRGFFPDNFV 53


>gnl|CDD|198281 cd10418, SH2_Src_Fyn_isoform_a_like, Src homology 2 (SH2) domain
          found in Fyn isoform a like proteins.  Fyn is a member
          of the Src non-receptor type tyrosine kinase family of
          proteins. This cd contains the SH2 domain found in Fyn
          isoform a type proteins.  Fyn is involved in the
          control of cell growth and is required in the following
          pathways: T and B cell receptor signaling,
          integrin-mediated signaling, growth factor and cytokine
          receptor signaling, platelet activation, ion channel
          function, cell adhesion, axon guidance, fertilization,
          entry into mitosis, and differentiation of natural
          killer cells, oligodendrocytes and keratinocytes. The
          protein associates with the p85 subunit of
          phosphatidylinositol 3-kinase and interacts with the
          Fyn-binding protein. Alternatively spliced transcript
          variants encoding distinct isoforms exist. Fyn is
          primarily localized to the cytoplasmic leaflet of the
          plasma membrane. Tyrosine phosphorylation of target
          proteins by Fyn serves to either regulate target
          protein activity, and/or to generate a binding site on
          the target protein that recruits other signaling
          molecules. FYN has been shown to interact with a number
          of proteins including: BCAR1, Cbl, Janus kinase,
          nephrin, Sky, tyrosine kinase, Wiskott-Aldrich syndrome
          protein, and Zap-70. Fyn has a unique N-terminal
          domain, an SH3 domain, an SH2 domain, a kinase domain
          and a regulatory tail, as do the other members of the
          family. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 45.4 bits (107), Expect = 2e-06
 Identities = 24/62 (38%), Positives = 36/62 (58%), Gaps = 6/62 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          WYFG + R++A+  LLS  +  G FL+R+S T  G Y L +++      + V HY I K+
Sbjct: 5  WYFGKLGRKDAERQLLSFGNPRGTFLIRESETTKGAYSLSIRDWDDMKGDHVKHYKIRKL 64

Query: 67 TN 68
           N
Sbjct: 65 DN 66


>gnl|CDD|198221 cd10358, SH2_PTK6_Brk, Src homology 2 domain found in
          protein-tyrosine kinase-6 (PTK6) which is also known as
          breast tumor kinase (Brk).  Human protein-tyrosine
          kinase-6 (PTK6, also known as breast tumor kinase
          (Brk)) is a member of the non-receptor protein-tyrosine
          kinase family and is expressed in two-thirds of all
          breast tumors. PTK6 (9). PTK6 contains a SH3 domain, a
          SH2 domain, and catalytic domains. For the case of the
          non-receptor protein-tyrosine kinases, the SH2 domain
          is typically involved in negative regulation of kinase
          activity by binding to a phosphorylated tyrosine
          residue near to the C terminus. The C-terminal sequence
          of PTK6 (PTSpYENPT where pY is phosphotyrosine) is
          thought to be a self-ligand for the SH2 domain. The
          structure of the SH2 domain resembles other SH2 domains
          except for a centrally located four-stranded
          antiparallel beta-sheet (strands betaA, betaB, betaC,
          and betaD). There are also differences in the loop
          length which might be responsible for PTK6 ligand
          specificity. There are two possible means of regulation
          of PTK6: autoinhibitory with the phosphorylation of Tyr
          playing a role in its negative regulation and
          autophosphorylation at this site, though it has been
          shown that PTK6 might phosphorylate signal
          transduction-associated proteins Sam68 and signal
          transducing adaptor family member 2 (STAP/BKS) in vivo.
          In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 100

 Score = 45.1 bits (106), Expect = 2e-06
 Identities = 27/86 (31%), Positives = 43/86 (50%), Gaps = 4/86 (4%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          W+FG ++R EA   L +E +  GAFL+R S     +YVL V++   V HY I +      
Sbjct: 4  WFFGCISRSEAVRRLQAEGNATGAFLIRVSEKPSADYVLSVRDTQAVRHYKIWRRAGGRL 63

Query: 72 QTCYKIGDKTFSDLPSLLAFYKVHYL 97
               +   +F  LP L+ +++   L
Sbjct: 64 HLNEAV---SFLSLPELVNYHRAQSL 86


>gnl|CDD|212705 cd11771, SH3_Pex13p_fungal, Src Homology 3 domain of fungal
           peroxisomal membrane protein Pex13p.  Pex13p, located in
           the peroxisomal membrane, contains two transmembrane
           regions and a C-terminal SH3 domain. It binds to the
           peroxisomal targeting type I (PTS1) receptor Pex5p and
           the docking factor Pex14p through its SH3 domain. It is
           essential for both PTS1 and PTS2 protein import pathways
           into the peroxisomal matrix. Pex13p binds Pex14p, which
           contains a PxxP motif, in a classical fashion to the
           proline-rich ligand binding site of its SH3 domain. It
           binds the WxxxF/Y motif of Pex5p in a novel site that
           does not compete with Pex14p binding. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 60

 Score = 43.8 bits (104), Expect = 2e-06
 Identities = 20/56 (35%), Positives = 29/56 (51%), Gaps = 6/56 (10%)

Query: 115 AKYDFDGNDPD-DLPFKKNDILIVVSK-----DEEHWWTAQNISGEVGSIPVPYVQ 164
           A YDF   +P+ +L  KK DI+ V+SK      +  WW  +   G +G  P  YV+
Sbjct: 4   ALYDFTPENPEMELSLKKGDIVAVLSKTDPLGRDSEWWKGRTRDGRIGWFPSNYVE 59



 Score = 35.3 bits (82), Expect = 0.002
 Identities = 20/60 (33%), Positives = 30/60 (50%), Gaps = 7/60 (11%)

Query: 207 FARVKQVRVPNAYDKTALKLEIGDIIKV-TKTNINGQ----WEGEL-NGKTGHFPFTHVE 260
           F R      P    +  L L+ GDI+ V +KT+  G+    W+G   +G+ G FP  +VE
Sbjct: 1   FCRALYDFTPEN-PEMELSLKKGDIVAVLSKTDPLGRDSEWWKGRTRDGRIGWFPSNYVE 59


>gnl|CDD|212900 cd11967, SH3_SASH1, Src homology 3 domain of SAM And SH3 Domain
           Containing Protein 1.  SASH1 is a potential tumor
           suppressor in breast and colon cancer. Its decreased
           expression is associated with aggressive tumor growth,
           metastasis, and poor prognosis. It is widely expressed
           in normal tissues (except lymphocytes and dendritic
           cells) and is localized in the nucleus and the
           cytoplasm. SASH1 interacts with the oncoprotein
           cortactin and is important in cell migration and
           adhesion. It is a member of the SLY family of proteins,
           which are adaptor proteins containing a central
           conserved region with a bipartite nuclear localization
           signal (NLS) as well as SAM (sterile alpha motif) and
           SH3 domains. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 43.9 bits (103), Expect = 2e-06
 Identities = 23/55 (41%), Positives = 30/55 (54%)

Query: 208 ARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEFI 262
           ARV     P+ YD  +LKL+ GDII +      G W G LN K G F F +V+ +
Sbjct: 3   ARVHTDFTPSPYDTDSLKLKKGDIIDIISKPPMGTWMGLLNNKVGTFKFIYVDVL 57


>gnl|CDD|212861 cd11928, SH3_SH3RF3_1, First Src Homology 3 domain of SH3 domain
           containing ring finger 3, an E3 ubiquitin-protein
           ligase.  SH3RF3 is also called POSH2 (Plenty of SH3s 2)
           or SH3MD4 (SH3 multiple domains protein 4). It is a
           scaffold protein with E3 ubiquitin-protein ligase
           activity. It was identified in the screen for
           interacting partners of p21-activated kinase 2 (PAK2).
           It may play a role in regulating JNK mediated apoptosis
           in certain conditions. It also interacts with GTP-loaded
           Rac1. SH3RF3 is highly homologous to SH3RF1; it also
           contains an N-terminal RING finger domain and four SH3
           domains. This model represents the first SH3 domain,
           located at the N-terminal half, of SH3RF3. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 43.8 bits (103), Expect = 2e-06
 Identities = 19/50 (38%), Positives = 32/50 (64%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A Y ++G +P DL F K DI+I+  K +E+W+  + ++G  G +P  Y+Q
Sbjct: 5   ALYSYEGKEPGDLKFNKGDIIILRRKVDENWYHGE-LNGCHGFLPASYIQ 53



 Score = 31.4 bits (71), Expect = 0.049
 Identities = 14/38 (36%), Positives = 22/38 (57%), Gaps = 2/38 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           LK   GDII + +  ++  W  GELNG  G  P ++++
Sbjct: 17  LKFNKGDII-ILRRKVDENWYHGELNGCHGFLPASYIQ 53


>gnl|CDD|198198 cd09945, SH2_SHB_SHD_SHE_SHF_like, Src homology 2 domain found in
          SH2 domain-containing adapter proteins B, D, E, and F
          (SHB, SHD, SHE, SHF).  SHB, SHD, SHE, and SHF are SH2
          domain-containing proteins that play various roles
          throughout the cell.  SHB functions in generating
          signaling compounds in response to tyrosine kinase
          activation. SHB contains proline-rich motifs, a
          phosphotyrosine binding (PTB) domain, tyrosine
          phosphorylation sites, and a SH2 domain. SHB mediates
          certain aspects of platelet-derived growth factor
          (PDGF) receptor-, fibroblast growth factor (FGF)
          receptor-, neural growth factor (NGF) receptor TRKA-, T
          cell receptor-, interleukin-2 (IL-2) receptor- and
          focal adhesion kinase- (FAK) signaling. SRC-like
          FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK)
          and SHB regulate apoptosis, proliferation and
          differentiation. SHB promotes apoptosis and is also
          required for proper mitogenicity, spreading and tubular
          morphogenesis in endothelial cells. SHB also plays a
          role in preventing early cavitation of embryoid bodies
          and reduces differentiation to cells expressing
          albumin, amylase, insulin and glucagon. SHB is a
          multifunctional protein that has difference responses
          in different cells under various conditions. SHE is
          expressed in heart, lung, brain, and skeletal muscle,
          while expression of SHD is restricted to the brain. SHF
          is mainly expressed in skeletal muscle, brain, liver,
          prostate, testis, ovary, small intestine, and colon.
          SHD may be a physiological substrate of c-Abl and may
          function as an adapter protein in the central nervous
          system. It is also thought to be involved in apoptotic
          regulation.  SHD contains five YXXP motifs, a substrate
          sequence preferred by Abl tyrosine kinases, in addition
          to a poly-proline rich region and a C-terminal SH2
          domain. SHE contains two pTry protein binding domains,
          protein interaction domain (PID) and a SH2 domain,
          followed by a glycine-proline rich region, all of which
          are N-terminal to the phosphotyrosine binding (PTB)
          domain. SHF contains  four putative tyrosine
          phosphorylation sites and an SH2 domain. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 98

 Score = 45.1 bits (107), Expect = 2e-06
 Identities = 25/85 (29%), Positives = 43/85 (50%), Gaps = 3/85 (3%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G +TR EA+++L   K+ G++LVR+S +   +Y L +K      H  I +  N   Q
Sbjct: 3  WYHGAITRIEAESLLRPCKE-GSYLVRNSESTKQDYSLSLKSAKGFMHMRIQR--NETGQ 59

Query: 73 TCYKIGDKTFSDLPSLLAFYKVHYL 97
                 + F  +P ++  Y ++ L
Sbjct: 60 YILGQFSRPFETIPEMIRHYCLNKL 84


>gnl|CDD|198226 cd10363, SH2_Src_HCK, Src homology 2 (SH2) domain found in HCK.
          HCK is a member of the Src non-receptor type tyrosine
          kinase family of proteins and is expressed in
          hemopoietic cells. HCK is proposed to couple the Fc
          receptor to the activation of the respiratory burst. It
          may also play a role in neutrophil migration and in the
          degranulation of neutrophils. It has two different
          translational starts that have different subcellular
          localization. HCK has been shown to interact with BCR
          gene,  ELMO1 Cbl gene, RAS p21 protein activator 1,
          RASA3, Granulocyte colony-stimulating factor receptor,
          ADAM15 and RAPGEF1.  Like the other members of the Src
          family the SH2 domain in addition to binding the
          target, also plays an autoinhibitory role by binding to
          its C-terminal tail.  In general SH2 domains are
          involved in signal transduction. HCK has a unique
          N-terminal domain, an SH3 domain, an SH2 domain, a
          kinase domain and a regulatory tail, as do the other
          members of the family. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 45.0 bits (106), Expect = 3e-06
 Identities = 29/87 (33%), Positives = 46/87 (52%), Gaps = 9/87 (10%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          W+F  ++R++A+  LL+  +  G+F++RDS T  G+Y L V++      + V HY   KI
Sbjct: 5  WFFKGISRKDAERQLLAPGNMLGSFMIRDSETTKGSYSLSVRDYDPQHGDTVKHY---KI 61

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFYK 93
             +    Y     TFS L  L+  YK
Sbjct: 62 RTLDNGGFYISPRSTFSTLQELVDHYK 88


>gnl|CDD|198231 cd10368, SH2_Src_Fyn, Src homology 2 (SH2) domain found in Fyn.
          Fyn is a member of the Src non-receptor type tyrosine
          kinase family of proteins. Fyn is involved in the
          control of cell growth and is required in the following
          pathways: T and B cell receptor signaling,
          integrin-mediated signaling, growth factor and cytokine
          receptor signaling, platelet activation, ion channel
          function, cell adhesion, axon guidance, fertilization,
          entry into mitosis, and differentiation of natural
          killer cells, oligodendrocytes and keratinocytes. The
          protein associates with the p85 subunit of
          phosphatidylinositol 3-kinase and interacts with the
          Fyn-binding protein. Alternatively spliced transcript
          variants encoding distinct isoforms exist. Fyn is
          primarily localized to the cytoplasmic leaflet of the
          plasma membrane. Tyrosine phosphorylation of target
          proteins by Fyn serves to either regulate target
          protein activity, and/or to generate a binding site on
          the target protein that recruits other signaling
          molecules. FYN has been shown to interact with a number
          of proteins including: BCAR1, Cbl, Janus kinase,
          nephrin, Sky, tyrosine kinase, Wiskott-Aldrich syndrome
          protein, and Zap-70. Fyn has a unique N-terminal
          domain, an SH3 domain, an SH2 domain, a kinase domain
          and a regulatory tail, as do the other members of the
          family. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 44.6 bits (105), Expect = 3e-06
 Identities = 24/62 (38%), Positives = 36/62 (58%), Gaps = 6/62 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          WYFG + R++A+  LLS  +  G FL+R+S T  G Y L +++      + V HY I K+
Sbjct: 5  WYFGKLGRKDAERQLLSFGNPRGTFLIRESETTKGAYSLSIRDWDDMKGDHVKHYKIRKL 64

Query: 67 TN 68
           N
Sbjct: 65 DN 66


>gnl|CDD|212772 cd11838, SH3_Intersectin_3, Third Src homology 3 domain (or SH3C)
           of Intersectin.  Intersectins (ITSNs) are adaptor
           proteins that function in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction.
           They are essential for initiating clathrin-coated pit
           formation. They bind to many proteins through their
           multidomain structure and facilitate the assembly of
           multimeric complexes. Vertebrates contain two ITSN
           proteins, ITSN1 and ITSN2, which exist in alternatively
           spliced short and long isoforms. The short isoforms
           contain two Eps15 homology domains (EH1 and EH2), a
           coiled-coil region and five SH3 domains (SH3A-E), while
           the long isoforms, in addition, contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin homology (PH)
           and C2 domains. ITSN1 and ITSN2 are both widely
           expressed, with variations depending on tissue type and
           stage of development. The third SH3 domain (or SH3C) of
           ITSN1 has been shown to bind many proteins including
           dynamin1/2, CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1,
           and WNK, among others. The SH3C of ITSN2 has been shown
           to bind the K15 protein of Kaposi's sarcoma-associated
           herpesvirus. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 43.2 bits (102), Expect = 3e-06
 Identities = 21/52 (40%), Positives = 28/52 (53%), Gaps = 2/52 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           IA Y ++ N+P DL F   D+++V  KD E WWT   I    G  P  YV+ 
Sbjct: 3   IALYPYESNEPGDLTFNAGDVILVTKKDGE-WWTG-TIGDRTGIFPSNYVRP 52



 Score = 28.9 bits (65), Expect = 0.40
 Identities = 15/37 (40%), Positives = 21/37 (56%), Gaps = 3/37 (8%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHV 259
           L    GD+I VTK +  G+W  G +  +TG FP  +V
Sbjct: 16  LTFNAGDVILVTKKD--GEWWTGTIGDRTGIFPSNYV 50


>gnl|CDD|212889 cd11956, SH3_srGAP4, Src homology 3 domain of Slit-Robo GTPase
           Activating Protein 4.  srGAP4, also called ARHGAP4, is
           highly expressed in hematopoietic cells and may play a
           role in lymphocyte differentiation. It is able to
           stimulate the GTPase activity of Rac1, Cdc42, and RhoA.
           In the nervous system, srGAP4 has been detected in
           differentiating neurites and may be involved in axon and
           dendritic growth. srGAPs are Rho GAPs that interact with
           Robo1, the transmembrane receptor of Slit proteins. Slit
           proteins are secreted proteins that control axon
           guidance and the migration of neurons and leukocytes.
           srGAPs contain an N-terminal F-BAR domain, a Rho GAP
           domain, and a C-terminal SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 43.3 bits (102), Expect = 3e-06
 Identities = 17/50 (34%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +A +D+ G    +L FK+ D+L++ SK    WW  +  +G  G IP  Y+
Sbjct: 5   VACFDYTGRTAQELSFKRGDVLLLHSKASSDWWRGE-HNGMRGLIPHKYI 53


>gnl|CDD|212882 cd11949, SH3_GRB2_C, C-terminal Src homology 3 domain of Growth
           factor receptor-bound protein 2.  GRB2 is a critical
           signaling molecule that regulates the Ras pathway by
           linking tyrosine kinases to the Ras guanine nucleotide
           releasing protein Sos (son of sevenless), which converts
           Ras to the active GTP-bound state. It is ubiquitously
           expressed in all tissues throughout development and is
           important in cell cycle progression, motility,
           morphogenesis, and angiogenesis. In lymphocytes, GRB2 is
           associated with antigen receptor signaling components.
           GRB2 contains an N-terminal SH3 domain, a central SH2
           domain, and a C-terminal SH3 domain. The C-terminal SH3
           domain of GRB2 binds to Gab2 (Grb2-associated binder 2)
           through epitopes containing RxxK motifs, as well as to
           the proline-rich C-terminus of FGRF2. SH3 domains are
           protein interaction domains that typically bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 42.9 bits (101), Expect = 4e-06
 Identities = 16/52 (30%), Positives = 26/52 (50%), Gaps = 1/52 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           V A +DFD  +  +L F++ D + V+   + +WW      G+ G  P  YV 
Sbjct: 2   VQALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGA-CHGQTGMFPRNYVT 52



 Score = 29.8 bits (67), Expect = 0.18
 Identities = 12/32 (37%), Positives = 18/32 (56%)

Query: 229 GDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           GD I+V   +    W+G  +G+TG FP  +V 
Sbjct: 21  GDFIEVMDNSDPNWWKGACHGQTGMFPRNYVT 52


>gnl|CDD|212753 cd11819, SH3_Cortactin_like, Src homology 3 domain of Cortactin and
           related proteins.  This subfamily includes cortactin,
           Abp1 (actin-binding protein 1), hematopoietic lineage
           cell-specific protein 1 (HS1), and similar proteins.
           These proteins are involved in regulating actin dynamics
           through direct or indirect interaction with the Arp2/3
           complex, which is required to initiate actin
           polymerization. They all contain at least one C-terminal
           SH3 domain. Cortactin and HS1 bind Arp2/3 and actin
           through an N-terminal region that contains an acidic
           domain and several copies of a repeat domain found in
           cortactin and HS1. Abp1 binds actin via an N-terminal
           actin-depolymerizing factor (ADF) homology domain. Yeast
           Abp1 binds Arp2/3 directly through two acidic domains.
           Mammalian Abp1 does not directly interact with Arp2/3;
           instead, it regulates actin dynamics indirectly by
           interacting with dynamin and WASP family proteins. The
           C-terminal region of these proteins acts as an adaptor
           or scaffold that can connect membrane trafficking and
           signaling proteins that bind the SH3 domain within the
           actin network. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 43.1 bits (102), Expect = 4e-06
 Identities = 15/51 (29%), Positives = 27/51 (52%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
            A YD+   + +++ F + DI+  + + +E WW   N  G+ G  P  YV+
Sbjct: 3   KALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVNAKGQKGLFPANYVE 53


>gnl|CDD|212775 cd11841, SH3_SH3YL1_like, Src homology 3 domain of SH3 domain
           containing Ysc84-like 1 (SH3YL1) protein.  SH3YL1
           localizes to the plasma membrane and is required for
           dorsal ruffle formation. It binds phosphoinositides
           (PIs) with high affinity through its N-terminal SYLF
           domain (also called DUF500). In addition, SH3YL1
           contains a C-terminal SH3 domain which has been reported
           to bind to N-WASP, dynamin 2, and SHIP2 (a PI
           5-phosphatase). SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 42.8 bits (101), Expect = 4e-06
 Identities = 19/54 (35%), Positives = 28/54 (51%), Gaps = 3/54 (5%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISGEVGSIPVPYVQ 164
           V A Y F+G  P DL F+  D + V+++ +    WW  + + G VG  P  YV 
Sbjct: 2   VTALYSFEGQQPCDLSFQAGDRITVLTRTDSQFDWWEGR-LRGRVGIFPANYVS 54



 Score = 35.4 bits (82), Expect = 0.002
 Identities = 16/38 (42%), Positives = 21/38 (55%), Gaps = 2/38 (5%)

Query: 224 LKLEIGDIIKV-TKTNI-NGQWEGELNGKTGHFPFTHV 259
           L  + GD I V T+T+     WEG L G+ G FP  +V
Sbjct: 16  LSFQAGDRITVLTRTDSQFDWWEGRLRGRVGIFPANYV 53


>gnl|CDD|212806 cd11873, SH3_CD2AP-like_1, First Src Homology 3 domain (SH3A) of
           CD2-associated protein and similar proteins.  This
           subfamily is composed of the first SH3 domain (SH3A) of
           CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and
           similar domains. CD2AP and CIN85 are adaptor proteins
           that bind to protein partners and assemble complexes
           that have been implicated in T cell activation, kidney
           function, and apoptosis of neuronal cells. They also
           associate with endocytic proteins, actin cytoskeleton
           components, and other adaptor proteins involved in
           receptor tyrosine kinase (RTK) signaling. CD2AP and the
           main isoform of CIN85 contain three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CD2AP and CIN85 to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           SH3A of both proteins bind to an atypical PXXXPR motif
           at the C-terminus of Cbl and the cytoplasmic domain of
           the cell adhesion protein CD2. CIN85 SH3A binds to
           internal proline-rich motifs within the proline-rich
           region; this intramolecular interaction serves as a
           regulatory mechanism to keep CIN85 in a closed
           conformation, preventing the recruitment of other
           proteins. CIN85 SH3A has also been shown to bind
           ubiquitin. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 42.6 bits (101), Expect = 5e-06
 Identities = 19/37 (51%), Positives = 22/37 (59%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L L++GDII   K    G WEG LNGK G FP   V+
Sbjct: 16  LTLKVGDIITNVKKMEEGWWEGTLNGKRGMFPDNFVK 52



 Score = 40.3 bits (95), Expect = 3e-05
 Identities = 20/54 (37%), Positives = 32/54 (59%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +VI ++D+D  +PD+L  K  DI+  V K EE WW    ++G+ G  P  +V+ 
Sbjct: 1   EVIVEFDYDAEEPDELTLKVGDIITNVKKMEEGWWEGT-LNGKRGMFPDNFVKV 53


>gnl|CDD|212931 cd11998, SH3_PACSIN1-2, Src homology 3 domain of Protein kinase C
           and Casein kinase Substrate in Neurons 1 (PACSIN1) and
           PACSIN 2.  PACSIN 1 or Syndapin I (Synaptic
           dynamin-associated protein I) is expressed specifically
           in the brain and is localized in neurites and synaptic
           boutons. It binds the brain-specific proteins dynamin I,
           synaptojanin, synapsin I, and neural Wiskott-Aldrich
           syndrome protein (nWASP), and functions as a link
           between the cytoskeletal machinery and synaptic vesicle
           endocytosis. PACSIN 1 interacts with huntingtin and may
           be implicated in the neuropathology of Huntington's
           disease. PACSIN 2 or Syndapin II is expressed
           ubiquitously and is involved in the regulation of
           tubulin polymerization. It associates with Golgi
           membranes and forms a complex with dynamin II which is
           crucial in promoting vesicle formation from the
           trans-Golgi network. PACSINs act as regulators of
           cytoskeletal and membrane dynamics. Vetebrates harbor
           three isoforms with distinct expression patterns and
           specific functions. PACSINs contain an N-terminal F-BAR
           domain and a C-terminal SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 43.0 bits (101), Expect = 5e-06
 Identities = 22/54 (40%), Positives = 32/54 (59%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVV-SKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V A YD+DG + D+L FK  D L  +  +DE+ W   +  SG+VG  P  YV+
Sbjct: 2   RVRALYDYDGQEQDELSFKAGDELTKLEDEDEQGWCKGRLDSGQVGLYPANYVE 55


>gnl|CDD|212879 cd11946, SH3_GRB2_N, N-terminal Src homology 3 domain of Growth
           factor receptor-bound protein 2.  GRB2 is a critical
           signaling molecule that regulates the Ras pathway by
           linking tyrosine kinases to the Ras guanine nucleotide
           releasing protein Sos (son of sevenless), which converts
           Ras to the active GTP-bound state. It is ubiquitously
           expressed in all tissues throughout development and is
           important in cell cycle progression, motility,
           morphogenesis, and angiogenesis. In lymphocytes, GRB2 is
           associated with antigen receptor signaling components.
           GRB2 contains an N-terminal SH3 domain, a central SH2
           domain, and a C-terminal SH3 domain. Its N-terminal SH3
           domain binds to Sos and Sos-derived proline-rich
           peptides. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 42.7 bits (100), Expect = 5e-06
 Identities = 20/53 (37%), Positives = 33/53 (62%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           + IAKYDF     D+L FK+ DIL V++++ +  W    ++G+ G IP  Y++
Sbjct: 2   EAIAKYDFKATADDELSFKRGDILKVLNEECDQNWYKAELNGKDGFIPKNYIE 54



 Score = 27.7 bits (61), Expect = 1.1
 Identities = 15/38 (39%), Positives = 21/38 (55%), Gaps = 1/38 (2%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           L  + GDI+KV     +  W + ELNGK G  P  ++E
Sbjct: 17  LSFKRGDILKVLNEECDQNWYKAELNGKDGFIPKNYIE 54


>gnl|CDD|212988 cd12055, SH3_CIN85_2, Second Src Homology 3 domain (SH3B) of
           Cbl-interacting protein of 85 kDa.  CIN85, also called
           SH3 domain-containing kinase-binding protein 1 (SH3KBP1)
           or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor
           protein that is involved in the downregulation of
           receptor tyrosine kinases by facilitating endocytosis
           through interaction with endophilin-associated ubiquitin
           ligase Cbl proteins. It is also important in many other
           cellular processes including vesicle-mediated transport,
           cytoskeletal remodelling, apoptosis, cell adhesion and
           migration, and viral infection, among others. CIN85
           exists as multiple variants from alternative splicing;
           the main variant contains three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CIN85 to bind
           various protein partners and assemble complexes that
           have been implicated in many different functions. This
           alignment model represents the second SH3 domain (SH3B)
           of CIN85. SH3B has been shown to bind Cbl proline-rich
           peptides and ubiquitin. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 42.7 bits (100), Expect = 5e-06
 Identities = 21/41 (51%), Positives = 27/41 (65%), Gaps = 2/41 (4%)

Query: 215 VPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           +P   D+  L+L++GDII+V      G WEG LNGKTG FP
Sbjct: 9   LPQNEDE--LELKVGDIIEVVGEVEEGWWEGVLNGKTGMFP 47



 Score = 28.8 bits (64), Expect = 0.43
 Identities = 14/41 (34%), Positives = 24/41 (58%), Gaps = 1/41 (2%)

Query: 125 DDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           D+L  K  DI+ VV + EE WW    ++G+ G  P  ++++
Sbjct: 14  DELELKVGDIIEVVGEVEEGWWEGV-LNGKTGMFPSNFIKE 53


>gnl|CDD|198282 cd10419, SH2_Src_Fyn_isoform_b_like, Src homology 2 (SH2) domain
          found in Fyn isoform b like proteins.  Fyn is a member
          of the Src non-receptor type tyrosine kinase family of
          proteins. This cd contains the SH2 domain found in Fyn
          isoform b type proteins. Fyn is involved in the control
          of cell growth and is required in the following
          pathways: T and B cell receptor signaling,
          integrin-mediated signaling, growth factor and cytokine
          receptor signaling, platelet activation, ion channel
          function, cell adhesion, axon guidance, fertilization,
          entry into mitosis, and differentiation of natural
          killer cells, oligodendrocytes and keratinocytes. The
          protein associates with the p85 subunit of
          phosphatidylinositol 3-kinase and interacts with the
          Fyn-binding protein. Alternatively spliced transcript
          variants encoding distinct isoforms exist. Fyn is
          primarily localized to the cytoplasmic leaflet of the
          plasma membrane. Tyrosine phosphorylation of target
          proteins by Fyn serves to either regulate target
          protein activity, and/or to generate a binding site on
          the target protein that recruits other signaling
          molecules. FYN has been shown to interact with a number
          of proteins including: BCAR1, Cbl, Janus kinase,
          nephrin, Sky, tyrosine kinase, Wiskott-Aldrich syndrome
          protein, and Zap-70. Fyn has a unique N-terminal
          domain, an SH3 domain, an SH2 domain, a kinase domain
          and a regulatory tail, as do the other members of the
          family. In general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 43.9 bits (103), Expect = 5e-06
 Identities = 24/62 (38%), Positives = 36/62 (58%), Gaps = 6/62 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKE-----NNKVSHYIINKI 66
          WYFG + R++A+  LLS  +  G FL+R+S T  G Y L +++      + V HY I K+
Sbjct: 5  WYFGKLGRKDAERQLLSFGNPRGTFLIRESETTKGAYSLSIRDWDDMKGDHVKHYKIRKL 64

Query: 67 TN 68
           N
Sbjct: 65 DN 66


>gnl|CDD|198270 cd10407, SH2_Vav3, Src homology 2 (SH2) domain found in the Vav3
          proteins.  Proto-oncogene vav is a member of the Dbl
          family of guanine nucleotide exchange factors (GEF) for
          the Rho family of GTP binding proteins. All vavs are
          activated by tyrosine phosphorylation leading to their
          activation. There are three Vav mammalian family
          members: Vav1 which is expressed in the hematopoietic
          system, and Vav2 and Vav3 are more ubiquitously
          expressed. Vav3 preferentially activates RhoA, RhoG
          and, to a lesser extent, Rac1.  Alternatively spliced
          transcript variants encoding different isoforms have
          been described for this gene.  VAV3 has been shown to
          interact with Grb2. Vav proteins are involved in
          several processes that require cytoskeletal
          reorganization, such as the formation of the
          immunological synapse (IS), phagocytosis, platelet
          aggregation, spreading, and transformation. Vavs
          function as guanine nucleotide exchange factors (GEFs)
          for the Rho/Rac family of GTPases. Vav family members
          have several conserved motifs/domains including: a
          leucine-rich region, a leucine-zipper, a calponin
          homology (CH) domain, an acidic domain, a Dbl-homology
          (DH) domain, a pleckstrin homology (PH) domain, a
          cysteine-rich domain, 2 SH3 domains,  a proline-rich
          region, and a SH2 domain. Vavs are the only known Rho
          GEFs that have both the DH/PH motifs and SH2/SH3
          domains in the same protein. The leucine-rich
          helix-loop-helix (HLH) domain is thought to be involved
          in protein heterodimerization with other HLH proteins
          and it may function as a negative regulator by forming
          inactive heterodimers. The CH domain  is usually
          involved in the association with filamentous actin, but
          in Vav it controls NFAT stimulation, Ca2+ mobilization,
          and its transforming activity. Acidic domains are
          involved in protein-protein interactions and contain
          regulatory tyrosines.  The DH domain is a GDP-GTP
          exchange factor on Rho/Rac GTPases. The PH domain in
          involved in interactions with GTP-binding proteins,
          lipids and/or phosphorylated serine/threonine residues.
           The SH3 domain is involved in localization of proteins
          to specific sites within the cell interacting with
          protein with proline-rich sequences. The SH2 domain
          mediates a high affinity interaction with tyrosine
          phosphorylated proteins. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 103

 Score = 43.8 bits (103), Expect = 5e-06
 Identities = 27/86 (31%), Positives = 42/86 (48%), Gaps = 7/86 (8%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G M R +A+  L++ + N  +LVR      G Y + +K NN+V H     I    + 
Sbjct: 7  WYAGAMERLQAETELIN-RVNSTYLVRHRTKESGEYAISIKYNNEVKH-----IKILTRD 60

Query: 73 TCYKIGD-KTFSDLPSLLAFYKVHYL 97
            + I + + F  L  L+ +YK H L
Sbjct: 61 GFFHIAENRKFKSLMELVEYYKHHSL 86


>gnl|CDD|198260 cd10397, SH2_Tec_Btk, Src homology 2 (SH2) domain found  in Tec
          protein, Bruton's tyrosine kinase (Btk).  A member of
          the Tec protein tyrosine kinase Btk is expressed in
          bone marrow, spleen, all hematopoietic cells except T
          lymphocytes and plasma cells where it plays a  crucial
          role in B cell maturation and mast cell activation. Btk
          has been shown to interact with GNAQ, PLCG2, protein
          kinase D1, B-cell linker, SH3BP5, caveolin 1, ARID3A,
          and GTF2I. Most of the Tec family members have a PH
          domain (Txk and the short (type 1) splice variant of
          Drosophila Btk29A are exceptions), a Tec homology (TH)
          domain, a SH3 domain, a SH2 domain, and a protein
          kinase catalytic domain. Btk is implicated in the
          primary immunodeficiency disease X-linked
          agammaglobulinemia (Bruton's agammaglobulinemia).  The
          TH domain consists of a Zn2+-binding Btk motif and a
          proline-rich region. The Btk motif is found in Tec
          kinases, Ras GAP, and IGBP.  It is crucial for the
          function of Tec PH domains and it's lack of presence in
          Txk is not surprising since it lacks a PH domain. The
          type 1 splice form of the Drosophila homolog also lacks
          both the PH domain and the Btk motif.  The proline-rich
          regions are highly conserved for the most part with the
          exception of Bmx whose residues surrounding the PXXP
          motif are not conserved (TH-like) and Btk29A  which is
          entirely unique with large numbers of glycine residues
          (TH-extended). Tec family members all lack a C-terminal
          tyrosine having an autoinhibitory function in its
          phosphorylated state. Two tyrosine phosphorylation (pY)
          sites have been identified in Btk: one located in the
          activation loop of the catalytic domain which regulates
          the transition between open (active) and closed
          (inactive) states and the other in its SH3 domain.  In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 106

 Score = 44.1 bits (104), Expect = 6e-06
 Identities = 27/95 (28%), Positives = 46/95 (48%), Gaps = 12/95 (12%)

Query: 6  DPHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCV------KENNKVS 59
          D  +   WY   MTR +A+ +L  E   G F+VRDS +  G Y + V           + 
Sbjct: 1  DSLEMYEWYSKNMTRSQAEQLLKQEGKEGGFIVRDS-SKAGKYTVSVFAKSAGDPQGVIR 59

Query: 60 HYIINKITNTEQQTCYKIGDK-TFSDLPSLLAFYK 93
          HY++     +  Q+ Y + +K  FS +P L+ +++
Sbjct: 60 HYVV----CSTPQSQYYLAEKHLFSTIPELINYHQ 90


>gnl|CDD|198207 cd10344, SH2_SLAP, Src homology 2 domain found in Src-like
          adaptor proteins.  SLAP belongs to the subfamily of
          adapter proteins that negatively regulate cellular
          signaling initiated by tyrosine kinases. It has a
          myristylated N-terminus, SH3 and SH2 domains with high
          homology to Src family tyrosine kinases, and a unique
          C-terminal tail, which is important for c-Cbl binding.
          SLAP negatively regulates platelet-derived growth
          factor (PDGF)-induced mitogenesis in fibroblasts and
          regulates F-actin assembly for dorsal ruffles
          formation. c-Cbl mediated SLAP inhibition towards actin
          remodeling. Moreover, SLAP enhanced PDGF-induced c-Cbl
          phosphorylation by SFK. In contrast, SLAP mitogenic
          inhibition was not mediated by c-Cbl, but it rather
          involved a competitive mechanism with SFK for
          PDGF-receptor (PDGFR) association and mitogenic
          signaling. Accordingly, phosphorylation of the Src
          mitogenic substrates Stat3 and Shc were reduced by
          SLAP. Thus, we concluded that SLAP regulates PDGFR
          signaling by two independent mechanisms: a competitive
          mechanism for PDGF-induced Src mitogenic signaling and
          a non-competitive mechanism for dorsal ruffles
          formation mediated by c-Cbl. SLAP is a hematopoietic
          adaptor containing Src homology (SH)3 and SH2 motifs
          and a unique carboxy terminus. Unlike c-Src, SLAP lacks
          a tyrosine kinase domain. Unlike c-Src, SLAP does not
          impact resorptive function of mature osteoclasts but
          induces their early apoptosis. SLAP negatively
          regulates differentiation of osteoclasts and
          proliferation of their precursors. Conversely, SLAP
          decreases osteoclast death by inhibiting activation of
          caspase 3. In general SH2 domains are involved in
          signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 104

 Score = 44.0 bits (104), Expect = 6e-06
 Identities = 26/88 (29%), Positives = 42/88 (47%), Gaps = 9/88 (10%)

Query: 11 NSWYFGMMTRQEAQAIL-LSEKDNGAFLVRDSNTILGNYVLCVK-----ENNKVSHYIIN 64
          + W F  ++R++A+ +L L     G+FL+R+S T  G Y L V+       + V HY I 
Sbjct: 10 HGWLFEGLSREKAEELLMLPGNQVGSFLIRESETRRGCYSLSVRHRGSQSRDSVKHYRIF 69

Query: 65 KITNTEQQTCYKIGDKTFSDLPSLLAFY 92
          ++ N      Y     TF  L  ++  Y
Sbjct: 70 RLDNG---WFYISPRLTFQCLEDMVNHY 94


>gnl|CDD|212888 cd11955, SH3_srGAP1-3, Src homology 3 domain of Slit-Robo GTPase
           Activating Proteins 1, 2, and 3.  srGAP1, also called
           Rho GTPase-Activating Protein 13 (ARHGAP13), is a Cdc42-
           and RhoA-specific GAP and is expressed later in the
           development of central nervous system tissues. srGAP2 is
           expressed in zones of neuronal differentiation. It plays
           a role in the regeneration of neurons and axons. srGAP3,
           also called MEGAP (MEntal disorder associated
           GTPase-Activating Protein), is a Rho GAP with activity
           towards Rac1 and Cdc42. It impacts cell migration by
           regulating actin and microtubule cytoskeletal dynamics.
           The association between srGAP3 haploinsufficiency and
           mental retardation is under debate. srGAPs are Rho GAPs
           that interact with Robo1, the transmembrane receptor of
           Slit proteins. Slit proteins are secreted proteins that
           control axon guidance and the migration of neurons and
           leukocytes. srGAPs contain an N-terminal F-BAR domain, a
           Rho GAP domain, and a C-terminal SH3 domain. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 42.2 bits (99), Expect = 7e-06
 Identities = 16/50 (32%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           IAK+D+ G    +L FKK   L++  +  + WW  ++ +G  G +P  Y+
Sbjct: 3   IAKFDYVGRSARELSFKKGASLLLYHRASDDWWEGRH-NGIDGLVPHQYI 51


>gnl|CDD|212741 cd11807, SH3_ASPP, Src homology 3 domain of Apoptosis Stimulating
           of p53 proteins (ASPP).  The ASPP family of proteins
           bind to important regulators of apoptosis (p53, Bcl-2,
           and RelA) and cell growth (APCL, PP1). They share
           similarity at their C-termini, where they harbor a
           proline-rich region, four ankyrin (ANK) repeats, and an
           SH3 domain. Vertebrates contain three members of the
           family: ASPP1, ASPP2, and iASPP. ASPP1 and ASPP2
           activate the apoptotic function of the p53 family of
           tumor suppressors (p53, p63, and p73), while iASPP is an
           oncoprotein that specifically inhibits p53-induced
           apoptosis. The expression of ASPP proteins is altered in
           tumors; ASPP1 and ASPP2 are downregulated whereas iASPP
           is upregulated is some cancer types. ASPP proteins also
           bind and regulate protein phosphatase 1 (PP1), and this
           binding is competitive with p53 binding. The SH3 domain
           and the ANK repeats of ASPP contribute to the p53
           binding site; they bind to the DNA binding domain of
           p53. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 42.4 bits (100), Expect = 7e-06
 Identities = 17/50 (34%), Positives = 29/50 (58%), Gaps = 4/50 (8%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSK---DEEHWWTAQNISGEVGSIP 159
           V A +D++  + D+L F++ D L V+ K   DE  WW A+  + + G +P
Sbjct: 3   VYALFDYEAENGDELSFREGDELTVLRKGDDDETEWWWARL-NDKEGYVP 51


>gnl|CDD|212930 cd11997, SH3_PACSIN3, Src homology 3 domain of Protein kinase C and
           Casein kinase Substrate in Neurons 3 (PACSIN3).  PACSIN
           3 or Syndapin III (Synaptic dynamin-associated protein
           III) is expressed ubiquitously and regulates glucose
           uptake in adipocytes through its role in GLUT1
           trafficking. It also modulates the subcellular
           localization and stimulus-specific function of the
           cation channel TRPV4. PACSINs act as regulators of
           cytoskeletal and membrane dynamics. Vetebrates harbor
           three isoforms with distinct expression patterns and
           specific functions. PACSINs contain an N-terminal F-BAR
           domain and a C-terminal SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 42.3 bits (99), Expect = 7e-06
 Identities = 19/54 (35%), Positives = 32/54 (59%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVS-KDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V A YD+ G + D+L FK  + L+ +  +DE+ W   + +SG +G  P  YV+
Sbjct: 3   RVRALYDYTGQEADELSFKAGEELLKIGEEDEQGWCKGRLLSGRIGLYPANYVE 56


>gnl|CDD|212807 cd11874, SH3_CD2AP-like_2, Second Src Homology 3 domain (SH3B) of
           CD2-associated protein and similar proteins.  This
           subfamily is composed of the second SH3 domain (SH3B) of
           CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and
           similar domains. CD2AP and CIN85 are adaptor proteins
           that bind to protein partners and assemble complexes
           that have been implicated in T cell activation, kidney
           function, and apoptosis of neuronal cells. They also
           associate with endocytic proteins, actin cytoskeleton
           components, and other adaptor proteins involved in
           receptor tyrosine kinase (RTK) signaling. CD2AP and the
           main isoform of CIN85 contain three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CD2AP and CIN85 to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           SH3B of both proteins have been shown to bind to Cbl. In
           the case of CD2AP, its SH3B binds to Cbl at a site
           distinct from the c-Cbl/SH3A binding site. The CIN85
           SH3B also binds ubiquitin. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 42.3 bits (100), Expect = 7e-06
 Identities = 18/37 (48%), Positives = 24/37 (64%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L+L++GD I+V      G WEG+LNGK G FP   V+
Sbjct: 16  LELKVGDTIEVLGEVEEGWWEGKLNGKVGVFPSNFVK 52



 Score = 28.5 bits (64), Expect = 0.54
 Identities = 14/40 (35%), Positives = 24/40 (60%), Gaps = 1/40 (2%)

Query: 125 DDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           D+L  K  D + V+ + EE WW  + ++G+VG  P  +V+
Sbjct: 14  DELELKVGDTIEVLGEVEEGWWEGK-LNGKVGVFPSNFVK 52


>gnl|CDD|212698 cd11764, SH3_Eps8, Src Homology 3 domain of Epidermal growth factor
           receptor kinase substrate 8 and similar proteins.  This
           group is composed of Eps8 and Eps8-like proteins
           including Eps8-like 1-3, among others. These proteins
           contain N-terminal Phosphotyrosine-binding (PTB),
           central SH3, and C-terminal effector domains. Eps8 binds
           either Abi1 (also called E3b1) or Rab5 GTPase activating
           protein RN-tre through its SH3 domain. With Abi1 and
           Sos1, it becomes part of a trimeric complex that is
           required to activate Rac. Together with RN-tre, it
           inhibits the internalization of EGFR. The SH3 domains of
           Eps8 and similar proteins recognize peptides containing
           a PxxDY motif, instead of the classical PxxP motif. SH3
           domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 41.9 bits (99), Expect = 9e-06
 Identities = 16/47 (34%), Positives = 23/47 (48%), Gaps = 1/47 (2%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIP 159
           V   YDF   +  +L   K + L V+  D   WW  +N  G+VG +P
Sbjct: 2   VRVLYDFTARNSKELSVLKGEYLEVLD-DSRQWWKVRNSRGQVGYVP 47


>gnl|CDD|212737 cd11803, SH3_Endophilin_A, Src homology 3 domain of Endophilin-A.
           Endophilins play roles in synaptic vesicle formation,
           virus budding, mitochondrial morphology maintenance,
           receptor-mediated endocytosis inhibition, and endosomal
           sorting. They are classified into two types, A and B.
           Vertebrates contain three endophilin-A isoforms (A1, A2,
           and A3). Endophilin-A proteins are enriched in the brain
           and play multiple roles in receptor-mediated
           endocytosis. They tubulate membranes and regulate
           calcium influx into neurons to trigger the activation of
           the endocytic machinery. They are also involved in the
           sorting of plasma membrane proteins, actin filament
           assembly, and the uncoating of clathrin-coated vesicles
           for fusion with endosomes. Endophilins contain an
           N-terminal N-BAR domain (BAR domain with an additional
           N-terminal amphipathic helix), followed by a variable
           region containing proline clusters, and a C-terminal SH3
           domain. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 41.9 bits (99), Expect = 9e-06
 Identities = 17/50 (34%), Positives = 32/50 (64%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A YDF+  +  +L FK+ DI+ + ++ +E+W+    ++G+ G  PV YV+
Sbjct: 5   ALYDFEPENEGELGFKEGDIITLTNQIDENWYEGM-VNGQSGFFPVNYVE 53



 Score = 38.8 bits (91), Expect = 1e-04
 Identities = 16/35 (45%), Positives = 23/35 (65%), Gaps = 2/35 (5%)

Query: 229 GDIIKVTKTNINGQW-EGELNGKTGHFPFTHVEFI 262
           GDII +T   I+  W EG +NG++G FP  +VE +
Sbjct: 22  GDIITLT-NQIDENWYEGMVNGQSGFFPVNYVEVL 55


>gnl|CDD|212800 cd11866, SH3_SKAP1-like, Src Homology 3 domain of Src
           Kinase-Associated Phosphoprotein 1 and similar proteins.
            This subfamily is composed of SKAP1, SKAP2, and similar
           proteins. SKAP1 and SKAP2 are immune cell-specific
           adaptor proteins that play roles in T- and B-cell
           adhesion, respectively, and are thus important in the
           migration of T- and B-cells to sites of inflammation and
           for movement during T-cell conjugation with
           antigen-presenting cells. Both SKAP1 and SKAP2 bind to
           ADAP (adhesion and degranulation-promoting adaptor
           protein), among many other binding partners. They
           contain a pleckstrin homology (PH) domain, a C-terminal
           SH3 domain, and several tyrosine phosphorylation sites.
           The SH3 domain of SKAP1 is necessary for its ability to
           regulate T-cell conjugation with antigen-presenting
           cells and the formation of LFA-1 clusters. SKAP1 binds
           primarily to a proline-rich region of ADAP through its
           SH3 domain; its degradation is regulated by ADAP. A
           secondary interaction occurs via the ADAP SH3 domain and
           the RKxxYxxY motif in SKAP1. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 41.6 bits (98), Expect = 1e-05
 Identities = 19/51 (37%), Positives = 33/51 (64%), Gaps = 3/51 (5%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSK--DEEHWWTAQNISGEVGSIPVPYV 163
             +D  GN+PD+L FK+ D++ ++SK  D   WW  + ++G+VG +P  Y+
Sbjct: 4   GLWDCSGNEPDELSFKRGDLIYIISKEYDSFGWWVGE-LNGKVGLVPKDYL 53



 Score = 27.8 bits (62), Expect = 0.88
 Identities = 13/34 (38%), Positives = 17/34 (50%), Gaps = 2/34 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQ--WEGELNGKTGHFP 255
           L  + GD+I +     +    W GELNGK G  P
Sbjct: 16  LSFKRGDLIYIISKEYDSFGWWVGELNGKVGLVP 49


>gnl|CDD|212844 cd11911, SH3_CIP4-like, Src Homology 3 domain of Cdc42-Interacting
           Protein 4.  This subfamily is composed of
           Cdc42-Interacting Protein 4 (CIP4), Formin Binding
           Protein 17 (FBP17), FormiN Binding Protein 1-Like
           (FNBP1L), and similar proteins. CIP4 and FNBP1L are
           Cdc42 effectors that bind Wiskott-Aldrich syndrome
           protein (WASP) and function in endocytosis. CIP4 and
           FBP17 bind to the Fas ligand and may be implicated in
           the inflammatory response. CIP4 may also play a role in
           phagocytosis. It functions downstream of Cdc42 in
           PDGF-dependent actin reorganization and cell migration,
           and also regulates the activity of PDGFRbeta. It uses
           Src as a substrate in regulating the invasiveness of
           breast tumor cells. CIP4 may also play a role in the
           pathogenesis of Huntington's disease. Members of this
           subfamily typically contain an N-terminal F-BAR
           (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, a
           central Cdc42-binding HR1 domain, and a C-terminal SH3
           domain. The SH3 domain of CIP4 associates with Gapex-5,
           a Rab31 GEF. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 41.9 bits (99), Expect = 1e-05
 Identities = 17/54 (31%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWT-AQNISGEVGSIPVPYVQ 164
              A YDFDG     L  ++ +IL+V+ +D    WT  +  +G+ G +P  Y++
Sbjct: 1   TCTALYDFDGTSEGTLSMEEGEILLVLEEDGGDGWTRVRKNNGDEGYVPTSYIE 54


>gnl|CDD|212812 cd11879, SH3_Bem1p_2, Second Src Homology 3 domain of Bud emergence
           protein 1 and similar domains.  Members of this
           subfamily bear similarity to Saccharomyces cerevisiae
           Bem1p, containing two Src Homology 3 (SH3) domains at
           the N-terminus, a central PX domain, and a C-terminal
           PB1 domain. Bem1p is a scaffolding protein that is
           critical for proper Cdc42p activation during bud
           formation in yeast. During budding and mating, Bem1p
           migrates to the plasma membrane where it can serve as an
           adaptor for Cdc42p and some other proteins. Bem1p also
           functions as an effector of the G1 cyclin Cln3p and the
           cyclin-dependent kinase Cdc28p in promoting vacuolar
           fusion. SH3 domains bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially to
           PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 56

 Score = 41.5 bits (98), Expect = 1e-05
 Identities = 19/53 (35%), Positives = 27/53 (50%), Gaps = 2/53 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI--SGEVGSIPVPYVQ 164
           I  YDF    PD+L  K  D +I+ +     W+ A+ I   G  G IPV +V+
Sbjct: 3   IVLYDFKAERPDELDAKAGDAIIICAHSNYEWFVAKPIGRLGGPGLIPVSFVE 55


>gnl|CDD|212743 cd11809, SH3_srGAP, Src homology 3 domain of Slit-Robo GTPase
           Activating Proteins.  Slit-Robo GTPase Activating
           Proteins (srGAPs) are Rho GAPs that interact with Robo1,
           the transmembrane receptor of Slit proteins. Slit
           proteins are secreted proteins that control axon
           guidance and the migration of neurons and leukocytes.
           Vertebrates contain three isoforms of srGAPs (srGAP1-3),
           all of which are expressed during embryonic and early
           development in the nervous system but with different
           localization and timing. A fourth member has also been
           reported (srGAP4, also called ARHGAP4). srGAPs contain
           an N-terminal F-BAR domain, a Rho GAP domain, and a
           C-terminal SH3 domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 41.6 bits (98), Expect = 1e-05
 Identities = 16/50 (32%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
            A++D+ G    +L FKK D L +  +  + WW  Q ++G+ G +P  Y+
Sbjct: 3   TAQFDYTGRSERELSFKKGDSLTLYRQVSDDWWRGQ-LNGQDGLVPHKYI 51


>gnl|CDD|198195 cd09942, SH2_nSH2_p85_like, N-terminal Src homology 2 (nSH2)
          domain found in p85.  Phosphoinositide 3-kinases
          (PI3Ks) are essential for cell growth, migration, and
          survival. p110, the catalytic subunit, is composed of
          an adaptor-binding domain, a Ras-binding domain, a C2
          domain, a helical domain, and a kinase domain.  The
          regulatory unit is called p85 and is composed of an SH3
          domain, a RhoGap domain, a N-terminal SH2 (nSH2)
          domain, an internal SH2 (iSH2) domain, and C-terminal
          (cSH2) domain.  There are 2 inhibitory interactions
          between p110alpha and p85 of P13K: (1) p85 nSH2 domain
          with the C2, helical, and kinase domains of p110alpha
          and (2) p85 iSH2 domain with C2 domain of p110alpha.
          There are 3 inhibitory interactions between p110beta
          and p85 of P13K: (1) p85 nSH2 domain with the C2,
          helical, and kinase domains of p110beta, (2) p85 iSH2
          domain with C2 domain of p110alpha, and (3) p85 cSH2
          domain with the kinase domain of p110alpha. It is
          interesting to note that p110beta is oncogenic as a
          wild type protein while p110alpha lacks this ability.
          One explanation is the idea that the regulation of
          p110beta by p85 is unique because of the addition of
          inhibitory contacts from the cSH2 domain and the loss
          of contacts in the iSH2 domain. In general SH2 domains
          are involved in signal transduction. They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 110

 Score = 43.1 bits (102), Expect = 1e-05
 Identities = 18/48 (37%), Positives = 32/48 (66%), Gaps = 3/48 (6%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK--ENNKV 58
          WY+G ++R+E    +  +  +G FLVRD++T+ G+Y L ++   NNK+
Sbjct: 9  WYWGDISREEVNEKM-RDTPDGTFLVRDASTMKGDYTLTLRKGGNNKL 55


>gnl|CDD|212755 cd11821, SH3_ASAP, Src homology 3 domain of ArfGAP with SH3 domain,
           ankyrin repeat and PH domain containing proteins.  ASAPs
           are Arf GTPase activating proteins (GAPs) and they
           function in regulating cell growth, migration, and
           invasion. They contain an N-terminal BAR domain,
           followed by a Pleckstrin homology (PH) domain, an Arf
           GAP domain, ankyrin (ANK) repeats, and a C-terminal SH3
           domain. Vertebrates contain at least three members,
           ASAP1, ASAP2, and ASAP3, but some ASAP3 proteins do not
           seem to harbor a C-terminal SH3 domain. ASAP1 and ASAP2
           show GTPase activating protein (GAP) activity towards
           Arf1 and Arf5. They do not show GAP activity towards
           Arf6, but are able to mediate Arf6 signaling by binding
           stably to GTP-Arf6. ASAP3 is an Arf6-specific GAP. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 41.5 bits (98), Expect = 1e-05
 Identities = 16/54 (29%), Positives = 30/54 (55%), Gaps = 4/54 (7%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGE---VGSIPVPY 162
           +V A YD   ++ D+L F + +I++V  ++++ WW    I G+    G  PV +
Sbjct: 1   RVRALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGH-IEGDPSRRGVFPVSF 53



 Score = 30.0 bits (68), Expect = 0.18
 Identities = 18/50 (36%), Positives = 21/50 (42%), Gaps = 8/50 (16%)

Query: 214 RVPNAYDKTA-----LKLEIGDIIKVTKTNINGQWEGELNGK---TGHFP 255
           RV   YD  A     L    G+II VT    +  WEG + G     G FP
Sbjct: 1   RVRALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGHIEGDPSRRGVFP 50


>gnl|CDD|212721 cd11787, SH3_SH3RF_2, Second Src Homology 3 domain of SH3 domain
           containing ring finger proteins.  This model represents
           the second SH3 domain of SH3RF1 (or POSH), SH3RF2 (or
           POSHER), SH3RF3 (POSH2), and similar domains. Members of
           this family are scaffold proteins that function as E3
           ubiquitin-protein ligases. They all contain an
           N-terminal RING finger domain and multiple SH3 domains;
           SH3RF1 and SH3RF3 have four SH3 domains while SH3RF2 has
           three. SH3RF1 plays a role in calcium homeostasis
           through the control of the ubiquitin domain protein
           Herp. It may also have a role in regulating death
           receptor mediated and JNK mediated apoptosis. SH3RF3
           interacts with p21-activated kinase 2 (PAK2) and
           GTP-loaded Rac1. It may play a role in regulating JNK
           mediated apoptosis in certain conditions. SH3RF2 acts as
           an anti-apoptotic regulator of the JNK pathway by
           binding to and promoting the degradation of SH3RF1. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 41.6 bits (98), Expect = 1e-05
 Identities = 16/52 (30%), Positives = 30/52 (57%), Gaps = 4/52 (7%)

Query: 114 IAKYDFDGNDPDD---LPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPY 162
            A YDF+  D D+   L FKK D++ V+ + +E+W   + +  ++G  P+ +
Sbjct: 3   KALYDFEMKDEDEKDCLTFKKGDVITVIRRVDENWAEGR-LGDKIGIFPISF 53


>gnl|CDD|212809 cd11876, SH3_MLK, Src Homology 3 domain of Mixed Lineage Kinases.
           MLKs are Serine/Threonine Kinases (STKs), catalyzing the
           transfer of the gamma-phosphoryl group from ATP to S/T
           residues on protein substrates. MLKs act as
           mitogen-activated protein kinase kinase kinases (MAP3Ks,
           MKKKs, MAPKKKs), which phosphorylate and activate MAPK
           kinases (MAPKKs or MKKs or MAP2Ks), which in turn
           phosphorylate and activate MAPKs during signaling
           cascades that are important in mediating cellular
           responses to extracellular signals. MLKs play roles in
           immunity and inflammation, as well as in cell death,
           proliferation, and cell cycle regulation. Mammals have
           four MLKs (MLK1-4), mostly conserved in vertebrates,
           which contain an SH3 domain, a catalytic kinase domain,
           a leucine zipper, a proline-rich region, and a CRIB
           domain that mediates binding to GTP-bound Cdc42 and Rac.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 41.7 bits (98), Expect = 1e-05
 Identities = 19/55 (34%), Positives = 29/55 (52%), Gaps = 6/55 (10%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKD-----EEHWWTAQNISGEVGSIPVPYVQ 164
           A +D+D    D+L  ++   + V+SKD     +E WWT + I  +VG  P  YV 
Sbjct: 4   ALFDYDARGEDELTLRRGQPVEVLSKDAAVSGDEGWWTGK-IGDKVGIFPSNYVA 57


>gnl|CDD|212773 cd11839, SH3_Intersectin_4, Fourth Src homology 3 domain (or SH3D)
           of Intersectin.  Intersectins (ITSNs) are adaptor
           proteins that function in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction.
           They are essential for initiating clathrin-coated pit
           formation. They bind to many proteins through their
           multidomain structure and facilitate the assembly of
           multimeric complexes. Vertebrates contain two ITSN
           proteins, ITSN1 and ITSN2, which exist in alternatively
           spliced short and long isoforms. The short isoforms
           contain two Eps15 homology domains (EH1 and EH2), a
           coiled-coil region and five SH3 domains (SH3A-E), while
           the long isoforms, in addition, contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin homology (PH)
           and C2 domains. ITSN1 and ITSN2 are both widely
           expressed, with variations depending on tissue type and
           stage of development. The fourth SH3 domain (or SH3D) of
           ITSN1 has been shown to bind SHIP2, Numb, CdGAP, and
           N-WASP. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 41.6 bits (98), Expect = 1e-05
 Identities = 18/55 (32%), Positives = 28/55 (50%), Gaps = 8/55 (14%)

Query: 214 RVPNAYDKTA---LKLEIGDIIKVTKTNINGQWEGELNGK-----TGHFPFTHVE 260
           +V   +  TA   L L +G ++ V K + +G WEGEL  +      G FP  +V+
Sbjct: 3   QVIAPFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQARGKKRQIGWFPANYVK 57


>gnl|CDD|212937 cd12004, SH3_Lyn, Src homology 3 domain of Lyn Protein Tyrosine
           Kinase.  Lyn is a member of the Src subfamily of
           proteins, which are cytoplasmic (or non-receptor) PTKs.
           Lyn is expressed in B lymphocytes and myeloid cells. It
           exhibits both positive and negative regulatory roles in
           B cell receptor (BCR) signaling. Lyn, as well as Fyn and
           Blk, promotes B cell activation by phosphorylating ITAMs
           (immunoreceptor tyr activation motifs) in CD19 and in Ig
           components of BCR. It negatively regulates signaling by
           its unique ability to phosphorylate ITIMs
           (immunoreceptor tyr inhibition motifs) in cell surface
           receptors like CD22 and CD5. Lyn also plays an important
           role in G-CSF receptor signaling by phosphorylating a
           variety of adaptor molecules. Src kinases contain an
           N-terminal SH4 domain with a myristoylation site,
           followed by SH3 and SH2 domains, a tyr kinase domain,
           and a regulatory C-terminal region containing a
           conserved tyr. They are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). The SH3 domain of Src kinases
           contributes to substrate recruitment by binding adaptor
           proteins/substrates, and regulation of kinase activity
           through an intramolecular interaction. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 41.5 bits (97), Expect = 1e-05
 Identities = 25/56 (44%), Positives = 34/56 (60%), Gaps = 6/56 (10%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISG-EVGSIPVPYVQK 165
           V+A Y +DG   DDL FKK + L V+   EEH  WW A++++  + G IP  YV K
Sbjct: 2   VVALYPYDGIHEDDLSFKKGEKLKVI---EEHGEWWKARSLTTKKEGFIPSNYVAK 54


>gnl|CDD|212740 cd11806, SH3_PRMT2, Src homology 3 domain of Protein arginine
           N-methyltransferase 2.  PRMT2, also called HRMT1L1,
           belongs to the arginine methyltransferase protein
           family. It functions as a coactivator to both estrogen
           receptor alpha (ER-alpha) and androgen receptor (AR),
           presumably through arginine methylation. The ER-alpha
           transcription factor is involved in cell proliferation,
           differentiation, morphogenesis, and apoptosis, and is
           also implicated in the development and progression of
           breast cancer. PRMT2 and its variants are upregulated in
           breast cancer cells and may be involved in modulating
           the ER-alpha signaling pathway during formation of
           breast cancer. PRMT2 also plays a role in regulating the
           function of E2F transcription factors, which are
           critical cell cycle regulators, by binding to the
           retinoblastoma gene product (RB). It contains an
           N-terminal SH3 domain and an AdoMet binding domain. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 41.2 bits (97), Expect = 1e-05
 Identities = 17/53 (32%), Positives = 25/53 (47%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
            +A  DF   D   L F+  D L+V+ K    WW A   +G  G IP  ++ +
Sbjct: 2   YVAIADFVATDDSQLSFESGDKLLVLRKPSVDWWWA-EHNGCCGYIPASHLHQ 53



 Score = 31.6 bits (72), Expect = 0.040
 Identities = 14/42 (33%), Positives = 20/42 (47%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           A D + L  E GD + V +      W  E NG  G+ P +H+
Sbjct: 10  ATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGCCGYIPASHL 51


>gnl|CDD|198263 cd10400, SH2_SAP1a, Src homology 2 (SH2) domain found in
           SLAM-associated protein (SAP) 1a.  The X-linked
           lymphoproliferative syndrome (XLP) gene encodes SAP
           (also called SH2D1A/DSHP) a protein that consists of a 5
           residue N-terminus, a single SH2 domain, and a short 25
           residue C-terminal tail. XLP is characterized by an
           extreme sensitivity to Epstein-Barr virus.  Both T and
           natural killer (NK) cell dysfunctions have been seen in
           XLP patients. SAP binds the cytoplasmic tail of
           Signaling lymphocytic activation molecule (SLAM), 2B4,
           Ly-9, and CD84. SAP is believed to function as a
           signaling inhibitor, by blocking or regulating binding
           of other signaling proteins. SAP and the SAP-like
           protein EAT-2 recognize the sequence motif TIpYXX[VI],
           which is found in the cytoplasmic domains of a
           restricted number of T, B, and NK cell surface receptors
           and are proposed to be natural inhibitors or regulators
           of the physiological role of a small family of receptors
           on the surface of these cells.  In general SH2 domains
           are involved in signal transduction. They typically bind
           pTyr-containing ligands via two surface pockets, a pTyr
           and hydrophobic binding pocket, allowing proteins with
           SH2 domains to localize to tyrosine phosphorylated
           sites.
          Length = 103

 Score = 42.5 bits (100), Expect = 2e-05
 Identities = 29/99 (29%), Positives = 51/99 (51%), Gaps = 5/99 (5%)

Query: 14  YFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNT---E 70
           Y G ++R+  + +LL+   +G++L+RDS ++ G Y LCV     V  Y +++ T T    
Sbjct: 6   YHGKISRETGEKLLLAAGLDGSYLLRDSESVPGVYCLCVLYKGYVYTYRVSQ-TETGSWS 64

Query: 71  QQTCYKIGDKTFSDLPSLL-AFYKVHYLDTSPLIKPATK 108
            +T   +  + F  + +L+ AF K      +PL  P  K
Sbjct: 65  AETAPGVHKRLFRKVKNLISAFQKPDQGIVTPLQYPVEK 103


>gnl|CDD|212860 cd11927, SH3_SH3RF1_1, First Src Homology 3 domain of SH3 domain
           containing ring finger protein 1, an E3
           ubiquitin-protein ligase.  SH3RF1 is also called POSH
           (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein
           2). It is a scaffold protein that acts as an E3
           ubiquitin-protein ligase. It plays a role in calcium
           homeostasis through the control of the ubiquitin domain
           protein Herp. It may also have a role in regulating
           death receptor mediated and JNK mediated apoptosis.
           SH3RF1 also enhances the ubiquitination of ROMK1
           potassium channel resulting in its increased
           endocytosis. It contains an N-terminal RING finger
           domain and four SH3 domains. This model represents the
           first SH3 domain, located at the N-terminal half, of
           SH3RF1. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 41.1 bits (96), Expect = 2e-05
 Identities = 18/50 (36%), Positives = 32/50 (64%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A Y+++G +P DL F K DI+I+  + +E+W+  + ++G  G  P  +VQ
Sbjct: 5   ALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGE-VNGIHGFFPTNFVQ 53



 Score = 26.8 bits (59), Expect = 2.0
 Identities = 15/38 (39%), Positives = 21/38 (55%), Gaps = 2/38 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           LK   GDII + +  ++  W  GE+NG  G FP   V+
Sbjct: 17  LKFSKGDII-ILRRQVDENWYHGEVNGIHGFFPTNFVQ 53


>gnl|CDD|212754 cd11820, SH3_STAM, Src homology 3 domain of Signal Transducing
           Adaptor Molecules.  STAMs were discovered as proteins
           that are highly phosphorylated following cytokine and
           growth factor stimulation. They function in cytokine
           signaling and surface receptor degradation, as well as
           regulate Golgi morphology. They associate with many
           proteins including Jak2 and Jak3 tyrosine kinases, Hrs,
           AMSH, and UBPY. STAM adaptor proteins contain VHS
           (Vps27, Hrs, STAM homology), ubiquitin interacting
           (UIM), and SH3 domains. There are two vertebrate STAMs,
           STAM1 and STAM2, which may be functionally redundant;
           vertebrate STAMs contain ITAM motifs. They are part of
           the endosomal sorting complex required for transport
           (ESCRT-0). STAM2 deficiency in mice did not cause any
           obvious abnormality, while STAM1 deficiency resulted in
           growth retardation. Loss of both STAM1 and STAM2 in mice
           proved lethal, indicating that STAMs are important for
           embryonic development. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 41.3 bits (97), Expect = 2e-05
 Identities = 19/54 (35%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           KV A YDF+  + ++L FK  +I+ V+   + +WW   N  GE G  P  +V  
Sbjct: 2   KVRALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGE-GLFPANFVTA 54



 Score = 27.0 bits (60), Expect = 1.8
 Identities = 11/38 (28%), Positives = 17/38 (44%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           A +   L  + G+II V   +    W+G  +   G FP
Sbjct: 11  AAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGEGLFP 48


>gnl|CDD|198278 cd10415, SH2_Grb10, Src homology 2 (SH2) domain found in the
          growth factor receptor bound, subclass 10 (Grb10)
          proteins.  The Grb family binds to the epidermal growth
          factor receptor (EGFR, erbB1) via their SH2 domains.
          Grb10 is part of the Grb7 family of proteins which also
          includes Grb7, and Grb14. They are composed of an
          N-terminal Proline-rich domain, a Ras Associating-like
          (RA) domain, a Pleckstrin Homology (PH) domain, a
          phosphotyrosine interaction region (PIR, BPS) and a
          C-terminal SH2 domain. The SH2 domains of Grb7, Grb10
          and Grb14 preferentially bind to a different RTK. Grb10
          has been shown to interact with many different
          proteins, including the insulin and IGF1 receptors,
          platelet-derived growth factor (PDGF) receptor-beta,
          Ret, Kit, Raf1 and MEK1, and Nedd4. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 108

 Score = 42.7 bits (100), Expect = 2e-05
 Identities = 26/91 (28%), Positives = 51/91 (56%), Gaps = 4/91 (4%)

Query: 8  HDRNSWYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNKVSHYIINKI 66
          H    W+ G ++R+E+  I+  +   +G FL+RDS +    +VL +  + K+ ++ I   
Sbjct: 2  HRTQHWFHGRISREESHRIIKQQGLVDGLFLLRDSQSNPKAFVLTLCHHQKIKNFQILPC 61

Query: 67 TNTEQQTCYKI--GDKTFSDLPSLLAFYKVH 95
           + + QT + +  G+  FSDL  L+ FY+++
Sbjct: 62 ED-DGQTFFSLDDGNTKFSDLIQLVDFYQLN 91


>gnl|CDD|198181 cd09927, SH2_Tensin_like, Src homology 2 domain found in
          Tensin-like proteins.  SH2 domain found in Tensin-like
          proteins. The Tensins are a family of intracellular
          proteins that interact with receptor tyrosine kinases
          (RTKs), integrins, and actin. They are thought act as
          signaling bridges between the extracellular space and
          the cytoskeleton. There are four homologues: Tensin1,
          Tensin2 (TENC1, C1-TEN), Tensin3 and Tensin4 (cten),
          all of which contain a C-terminal tandem SH2-PTB domain
          pairing, as well as actin-binding regions that may
          localize them to focal adhesions. The isoforms of
          Tensin2 and Tensin3 contain N-terminal C1 domains,
          which are atypical and not expected to bind to phorbol
          esters. Tensins 1-3 contain a phosphatase (PTPase) and
          C2 domain pairing which resembles PTEN (phosphatase and
          tensin homologue deleted on chromosome 10) protein.
          PTEN is a lipid phosphatase that dephosphorylates
          phosphatidylinositol 3,4,5-trisphosphate
          (PtdIns(3,4,5)P3) to yield phosphatidylinositol
          4,5-bisphosphate (PtdIns(4,5)P2). As PtdIns(3,4,5)P3 is
          the product of phosphatidylinositol 3-kinase (PI3K)
          activity, PTEN is therefore a key negative regulator of
          the PI3K pathway. Because of their PTEN-like domains,
          the Tensins may also possess phosphoinositide-binding
          or phosphatase capabilities. However, only Tensin2 and
          Tensin3 have the potential to be phosphatases since
          only their PTPase domains contain a cysteine residue
          that is essential for catalytic activity. In general
          SH2 domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 116

 Score = 42.8 bits (101), Expect = 2e-05
 Identities = 21/41 (51%), Positives = 25/41 (60%), Gaps = 1/41 (2%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK 53
          WY   ++R +A A LL +K  G FLVRDS T  G Y L VK
Sbjct: 5  WYKPNISRDQAIA-LLKDKPPGTFLVRDSTTYKGAYGLAVK 44


>gnl|CDD|198254 cd10391, SH2_SHE, Src homology 2 domain found in SH2
           domain-containing adapter protein E (SHE).  SHE is
           expressed in heart, lung, brain, and skeletal muscle.
           SHE contains two pTry protein binding domains, protein
           interaction domain (PID) and a SH2 domain, followed by a
           glycine-proline rich region, all of which are N-terminal
           to the phosphotyrosine binding (PTB) domain. In general
           SH2 domains are involved in signal transduction. They
           typically bind pTyr-containing ligands via two surface
           pockets, a pTyr and hydrophobic binding pocket, allowing
           proteins with SH2 domains to localize to tyrosine
           phosphorylated sites.
          Length = 98

 Score = 42.3 bits (99), Expect = 2e-05
 Identities = 25/94 (26%), Positives = 42/94 (44%), Gaps = 14/94 (14%)

Query: 12  SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITN--- 68
            WY G ++R EA++ L   K+  ++LVR+S +    Y + +K +    H I+ +  +   
Sbjct: 2   PWYHGSISRAEAESRLQPCKE-ASYLVRNSESGNSKYSIALKTSQGCVHIIVAQTKDNKY 60

Query: 69  TEQQTCYKIGDKTFSDLPSLLAFYKVHYLDTSPL 102
           T  QT        F  +P +     VHY     L
Sbjct: 61  TLNQTS-----AVFDSIPEV-----VHYYSNEKL 84


>gnl|CDD|212941 cd12008, SH3_Src, Src homology 3 domain of Src Protein Tyrosine
           Kinase.  Src (or c-Src) is a cytoplasmic (or
           non-receptor) PTK and is the vertebrate homolog of the
           oncogenic protein (v-Src) from Rous sarcoma virus.
           Together with other Src subfamily proteins, it is
           involved in signaling pathways that regulate cytokine
           and growth factor responses, cytoskeleton dynamics, cell
           proliferation, survival, and differentiation. Src also
           play a role in regulating cell adhesion, invasion, and
           motility in cancer cells, and tumor vasculature,
           contributing to cancer progression and metastasis.
           Elevated levels of Src kinase activity have been
           reported in a variety of human cancers. Several
           inhibitors of Src have been developed as anti-cancer
           drugs. Src is also implicated in acute inflammatory
           responses and osteoclast function. Src kinases contain
           an N-terminal SH4 domain with a myristoylation site,
           followed by SH3 and SH2 domains, a tyr kinase domain,
           and a regulatory C-terminal region containing a
           conserved tyr. They are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). The SH3 domain of Src kinases
           contributes to substrate recruitment by binding adaptor
           proteins/substrates, and regulation of kinase activity
           through an intramolecular interaction. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 40.9 bits (95), Expect = 3e-05
 Identities = 20/51 (39%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNIS-GEVGSIPVPYV 163
           +A YD++     DL FKK + L +V+  E  WW A +++ G+ G IP  YV
Sbjct: 3   VALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQTGYIPSNYV 53


>gnl|CDD|212939 cd12006, SH3_Fyn_Yrk, Src homology 3 domain of Fyn and Yrk Protein
           Tyrosine Kinases.  Fyn and Yrk (Yes-related kinase) are
           members of the Src subfamily of proteins, which are
           cytoplasmic (or non-receptor) PTKs. Fyn, together with
           Lck, plays a critical role in T-cell signal transduction
           by phosphorylating ITAM (immunoreceptor tyr activation
           motif) sequences on T-cell receptors, ultimately leading
           to the proliferation and differentiation of T-cells. In
           addition, Fyn is involved in the myelination of neurons,
           and is implicated in Alzheimer's and Parkinson's
           diseases. Yrk has been detected only in chickens. It is
           primarily found in neuronal and epithelial cells and in
           macrophages. It may play a role in inflammation and in
           response to injury. Src kinases contain an N-terminal
           SH4 domain with a myristoylation site, followed by SH3
           and SH2 domains, a tyr kinase domain, and a regulatory
           C-terminal region containing a conserved tyr. They are
           activated by autophosphorylation at the tyr kinase
           domain, but are negatively regulated by phosphorylation
           at the C-terminal tyr by Csk (C-terminal Src Kinase).
           The SH3 domain of Src kinases contributes to substrate
           recruitment by binding adaptor proteins/substrates, and
           regulation of kinase activity through an intramolecular
           interaction. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 40.8 bits (95), Expect = 3e-05
 Identities = 19/51 (37%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYV 163
           +A YD++    DDL F K +   +++  E  WW A+++ +GE G IP  YV
Sbjct: 4   VALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGETGYIPSNYV 54


>gnl|CDD|198205 cd10342, SH2_SAP1, Src homology 2 (SH2) domain found in
          SLAM-associated protein (SAP)1.  The X-linked
          lymphoproliferative syndrome (XLP) gene encodes SAP
          (also called SH2D1A/DSHP) a protein that consists of a
          5 residue N-terminus, a single SH2 domain, and a short
          25 residue C-terminal tail.  XLP is characterized by an
          extreme sensitivity to Epstein-Barr virus.  Both T and
          natural killer (NK) cell dysfunctions have been seen in
          XLP patients. SAP binds the cytoplasmic tail of
          Signaling lymphocytic activation molecule (SLAM), 2B4,
          Ly-9, and CD84. SAP is believed to function as a
          signaling inhibitor, by blocking or regulating binding
          of other signaling proteins. SAP and the SAP-like
          protein EAT-2 recognize the sequence motif TIpYXX[VI],
          which is found in the cytoplasmic domains of a
          restricted number of T, B, and NK cell surface
          receptors and are proposed to be natural inhibitors or
          regulators of the physiological role of a small family
          of receptors on the surface of these cells.  In general
          SH2 domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 103

 Score = 41.9 bits (98), Expect = 3e-05
 Identities = 16/65 (24%), Positives = 35/65 (53%), Gaps = 4/65 (6%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
           Y G ++R+  + +LL+   +G++L+RDS ++ G Y LCV  +  +  Y +++     + 
Sbjct: 5  VYHGKISRETGEKLLLATGLDGSYLLRDSESVPGVYCLCVLYHGYIYTYRVSQ----TET 60

Query: 73 TCYKI 77
            +  
Sbjct: 61 GSWSA 65


>gnl|CDD|198265 cd10402, SH2_C-SH2_Zap70, C-terminal Src homology 2 (SH2) domain
          found in Zeta-chain-associated protein kinase 70
          (ZAP-70).  ZAP-70 and Syk comprise a family of
          hematopoietic cell specific protein tyrosine kinases
          (PTKs) that are required for antigen and antibody
          receptor function. ZAP-70 is expressed in T and natural
          killer (NK) cells  and Syk is expressed in B cells,
          mast cells, polymorphonuclear leukocytes, platelets,
          macrophages, and immature T cells. They are required
          for the proper development of T and B cells, immune
          receptors, and activating NK cells. They consist of two
          N-terminal Src homology 2 (SH2) domains and a
          C-terminal kinase domain separated from the SH2 domains
          by a linker or hinge region. Phosphorylation of both
          tyrosine residues within the Immunoreceptor
          Tyrosine-based Activation Motifs (ITAM; consensus
          sequence Yxx[LI]x(7,8)Yxx[LI]) by the Src-family PTKs
          is required for efficient interaction of ZAP-70 and Syk
          with the receptor subunits and for receptor function.
          ZAP-70 forms two phosphotyrosine binding pockets, one
          of which is shared by both SH2 domains.  In Syk the two
          SH2 domains do not form such a phosphotyrosine-binding
          site.  The SH2 domains here are believed to function
          independently. In addition, the two SH2 domains of Syk
          display flexibility in their relative orientation,
          allowing Syk to accommodate a greater variety of
          spacing sequences between the ITAM phosphotyrosines and
          singly phosphorylated non-classical ITAM ligands. This
          model contains the C-terminus SH2 domains of Zap70. In
          general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 105

 Score = 41.8 bits (98), Expect = 3e-05
 Identities = 21/59 (35%), Positives = 31/59 (52%), Gaps = 2/59 (3%)

Query: 8  HDRNSWYFGMMTRQEAQAILLS-EKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINK 65
          H+R  WY G + R EA+  L S  + +G FL+R+     G Y L +     V HY I++
Sbjct: 7  HERMPWYHGSIARDEAERRLYSGAQPDGKFLLRERKE-SGTYALSLVYGKTVYHYRIDQ 64


>gnl|CDD|212707 cd11773, SH3_Sla1p_1, First Src Homology 3 domain of the fungal
           endocytic adaptor protein Sla1p.  Sla1p facilitates
           endocytosis by playing a role as an adaptor protein in
           coupling components of the actin cytoskeleton to the
           endocytic machinery. It interacts with Abp1p, Las17p and
           Pan1p, which are activator proteins of actin-related
           protein 2/3 (Arp2/3). Sla1p contains multiple domains
           including three SH3 domains, a SAM (sterile alpha motif)
           domain, and a Sla1 homology domain 1 (SHD1), which binds
           to the NPFXD motif that is found in many integral
           membrane proteins such as the Golgi-localized
           Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and
           Dnf1p. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 40.5 bits (95), Expect = 3e-05
 Identities = 15/54 (27%), Positives = 27/54 (50%), Gaps = 6/54 (11%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTA------QNISGEVGSIPVPY 162
           A YD++    D+L  +++DIL ++ K ++ WW         +    VG +P  Y
Sbjct: 4   ALYDYEPQTEDELTIQEDDILYLLEKSDDDWWKVKLKVNSSDDDEPVGLVPATY 57


>gnl|CDD|212938 cd12005, SH3_Lck, Src homology 3 domain of Lck Protein Tyrosine
           Kinase.  Lck is a member of the Src subfamily of
           proteins, which are cytoplasmic (or non-receptor) PTKs.
           Lck is expressed in T-cells and natural killer cells. It
           plays a critical role in T-cell maturation, activation,
           and T-cell receptor (TCR) signaling. Lck phosphorylates
           ITAM (immunoreceptor tyr activation motif) sequences on
           several subunits of TCRs, leading to the activation of
           different second messenger cascades. Phosphorylated
           ITAMs serve as binding sites for other signaling factor
           such as Syk and ZAP-70, leading to their activation and
           propagation of downstream events. In addition, Lck
           regulates drug-induced apoptosis by interfering with the
           mitochondrial death pathway. The apototic role of Lck is
           independent of its primary function in T-cell signaling.
           Src kinases contain an N-terminal SH4 domain with a
           myristoylation site, followed by SH3 and SH2 domains, a
           tyr kinase domain, and a regulatory C-terminal region
           containing a conserved tyr. They are activated by
           autophosphorylation at the tyr kinase domain, but are
           negatively regulated by phosphorylation at the
           C-terminal tyr by Csk (C-terminal Src Kinase). The SH3
           domain of Src kinases contributes to substrate
           recruitment by binding adaptor proteins/substrates, and
           regulation of kinase activity through an intramolecular
           interaction. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 40.6 bits (95), Expect = 3e-05
 Identities = 19/54 (35%), Positives = 33/54 (61%), Gaps = 2/54 (3%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYVQK 165
           V+A Y ++ +   DL F+K + L ++ +  E WW AQ++ +G+ G IP  +V K
Sbjct: 2   VVALYSYEPSHDGDLGFEKGEKLRILEQSGE-WWKAQSLTTGQEGFIPFNFVAK 54


>gnl|CDD|212763 cd11829, SH3_GAS7, Src homology 3 domain of Growth Arrest Specific
           protein 7.  GAS7 is mainly expressed in the brain and is
           required for neurite outgrowth. It may also play a role
           in the protection and migration of embryonic stem cells.
           Treatment-related acute myeloid leukemia (AML) has been
           reported resulting from mixed-lineage leukemia
           (MLL)-GAS7 translocations as a complication of primary
           cancer treatment. GAS7 contains an N-terminal SH3
           domain, followed by a WW domain, and a central F-BAR
           domain. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 40.6 bits (95), Expect = 3e-05
 Identities = 15/36 (41%), Positives = 22/36 (61%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           L  E G++I+V +    G WEGE +G  G FP ++V
Sbjct: 17  LSFEAGELIRVLQAPDGGWWEGEKDGLRGWFPASYV 52


>gnl|CDD|212993 cd12060, SH3_alphaPIX, Src Homology 3 domain of alpha-Pak
           Interactive eXchange factor.  Alpha-PIX, also called Rho
           guanine nucleotide exchange factor 6 (ARHGEF6) or Cool
           (Cloned out of Library)-2, activates small GTPases by
           exchanging bound GDP for free GTP. It acts as a GEF for
           both Cdc42 and Rac 1, and is localized in dendritic
           spines where it regulates spine morphogenesis. It
           controls dendritic length and spine density in the
           hippocampus. Mutations in the ARHGEF6 gene cause
           X-linked intellectual disability in humans. PIX proteins
           contain an N-terminal SH3 domain followed by RhoGEF
           (also called Dbl-homologous or DH) and Pleckstrin
           Homology (PH) domains, and a C-terminal leucine-zipper
           domain for dimerization. The SH3 domain of PIX binds to
           an atypical PxxxPR motif in p21-activated kinases (PAKs)
           with high affinity. The binding of PAKs to PIX
           facilitate the localization of PAKs to focal complexes
           and also localizes PAKs to PIX targets Cdc43 and Rac,
           leading to the activation of PAKs. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 58

 Score = 40.8 bits (95), Expect = 3e-05
 Identities = 19/32 (59%), Positives = 21/32 (65%)

Query: 229 GDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           GDII VT+    G WEG LNGKTG FP  +V 
Sbjct: 23  GDIIYVTRVEEGGWWEGTLNGKTGWFPSNYVR 54



 Score = 35.7 bits (82), Expect = 0.002
 Identities = 17/54 (31%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQKY 166
           V A+++F   + D+L   K DI+ V   +E  WW    ++G+ G  P  YV++ 
Sbjct: 4   VKARFNFKQTNEDELSVCKGDIIYVTRVEEGGWWEG-TLNGKTGWFPSNYVREI 56


>gnl|CDD|212700 cd11766, SH3_Nck_2, Second Src Homology 3 domain of Nck adaptor
           proteins.  Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4), which show partly
           overlapping functions but also bind distinct targets.
           Their SH3 domains are involved in recruiting downstream
           effector molecules, such as the N-WASP/Arp2/3 complex,
           which when activated induces actin polymerization that
           results in the production of pedestals, or protrusions
           of the plasma membrane. The second SH3 domain of Nck
           appears to prefer ligands containing the APxxPxR motif.
           SH3 domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially a PxxP motif. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 40.3 bits (95), Expect = 3e-05
 Identities = 15/54 (27%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
             + K++++    D+L  +K D ++V+ K  + WW  +   G+VG  P  YV +
Sbjct: 1   PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECN-GQVGWFPSNYVTE 53



 Score = 36.1 bits (84), Expect = 0.001
 Identities = 15/37 (40%), Positives = 21/37 (56%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L L  GD + V + + +G W GE NG+ G FP  +V 
Sbjct: 16  LSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYVT 52


>gnl|CDD|212853 cd11920, SH3_Sorbs2_1, First Src Homology 3 domain of Sorbin and
           SH3 domain containing 2 (Sorbs2), also called
           Arg-binding protein 2 (ArgBP2).  Sorbs2 or ArgBP2 is an
           adaptor protein containing one sorbin homology (SoHo)
           and three SH3 domains. It regulates actin-dependent
           processes including cell adhesion, morphology, and
           migration. It is expressed in many tissues and is
           abundant in the heart. Like vinexin, it is found in
           focal adhesion where it interacts with vinculin and
           afadin. It also localizes in epithelial cell stress
           fibers and in cardiac muscle cell Z-discs. Sorbs2 has
           been implicated to play roles in the signaling of c-Arg,
           Akt, and Pyk2. Other interaction partners of Sorbs2
           include c-Abl, flotillin, spectrin, dynamin 1/2,
           synaptojanin, PTP-PEST, among others. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 40.4 bits (94), Expect = 3e-05
 Identities = 18/51 (35%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           A YDF      +L FKK D + ++ K +++W+  ++  G VG  P+ YV+K
Sbjct: 5   AVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGEH-HGRVGIFPISYVEK 54



 Score = 28.4 bits (63), Expect = 0.63
 Identities = 12/37 (32%), Positives = 21/37 (56%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           L  + GD + + +      +EGE +G+ G FP ++VE
Sbjct: 17  LSFKKGDTVYILRKIDQNWYEGEHHGRVGIFPISYVE 53


>gnl|CDD|212803 cd11870, SH3_p67phox-like_C, C-terminal Src Homology 3 domain of
           the p67phox subunit of NADPH oxidase and similar
           proteins.  This subfamily is composed of p67phox, NADPH
           oxidase activator 1 (Noxa1), and similar proteins.
           p67phox, also called Neutrophil cytosol factor 2
           (NCF-2), and Noxa1 are homologs and are the cytosolic
           subunits of the phagocytic (Nox2) and nonphagocytic
           (Nox1) NADPH oxidase complexes, respectively. NADPH
           oxidase catalyzes the transfer of electrons from NADPH
           to oxygen during phagocytosis forming superoxide and
           reactive oxygen species. p67phox and Noxa1 play
           regulatory roles. p67phox contains N-terminal TPR, first
           SH3 (or N-terminal or central SH3), PB1, and C-terminal
           SH3 domains. Noxa1 has a similar domain architecture
           except it is lacking the N-terminal SH3 domain. The TPR
           domain of both binds activated GTP-bound Rac, while the
           C-terminal SH3 domain of p67phox and Noxa1 binds the
           polyproline motif found at the C-terminus of p47phox and
           Noxo1, respectively. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 40.2 bits (94), Expect = 3e-05
 Identities = 16/53 (30%), Positives = 29/53 (54%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V+A + ++   P+DL F++ D + V+S+  E W    +  G VG  P  +V 
Sbjct: 1   QVVALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHS-DGRVGIFPKCFVV 52



 Score = 27.5 bits (61), Expect = 1.4
 Identities = 13/33 (39%), Positives = 17/33 (51%), Gaps = 2/33 (6%)

Query: 229 GDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           GD I V  + +N  W EG  +G+ G FP   V 
Sbjct: 21  GDTIDVL-SEVNEAWLEGHSDGRVGIFPKCFVV 52


>gnl|CDD|212932 cd11999, SH3_PACSIN_like, Src homology 3 domain of an unknown
           subfamily of proteins with similarity to Protein kinase
           C and Casein kinase Substrate in Neurons (PACSIN)
           proteins.  PACSINs, also called Synaptic
           dynamin-associated proteins (Syndapins), act as
           regulators of cytoskeletal and membrane dynamics. They
           bind both dynamin and Wiskott-Aldrich syndrome protein
           (WASP), and may provide direct links between the actin
           cytoskeletal machinery through WASP and
           dynamin-dependent endocytosis. Vetebrates harbor three
           isoforms with distinct expression patterns and specific
           functions. PACSINs contain an N-terminal F-BAR domain
           and a C-terminal SH3 domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 56

 Score = 40.3 bits (94), Expect = 3e-05
 Identities = 21/54 (38%), Positives = 30/54 (55%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVS-KDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V A YD+ G +PD+L FK  + L+ V  +DE+ W       G VG  P  YV+
Sbjct: 3   RVRAVYDYTGQEPDELSFKAGEELLKVEDEDEQGWCKGVTDGGAVGLYPANYVE 56


>gnl|CDD|212742 cd11808, SH3_Alpha_Spectrin, Src homology 3 domain of Alpha
           Spectrin.  Spectrin is a major structural component of
           the red blood cell membrane skeleton and is important in
           erythropoiesis and membrane biogenesis. It is a
           flexible, rope-like molecule composed of two subunits,
           alpha and beta, which consist of many spectrin-type
           repeats. Alpha and beta spectrin associate to form
           heterodimers and tetramers; spectrin tetramer formation
           is critical for red cell shape and deformability.
           Defects in alpha spectrin have been associated with
           inherited hemolytic anemias including hereditary
           spherocytosis (HSp), hereditary elliptocytosis (HE), and
           hereditary pyropoikilocytosis (HPP). Alpha spectrin
           contains a middle SH3 domain and a C-terminal EF-hand
           binding motif in addition to multiple spectrin repeats.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 40.2 bits (94), Expect = 4e-05
 Identities = 17/54 (31%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
            V+A YD+    P ++  KK DIL +++   + WW  +  +   G +P  YV+K
Sbjct: 1   CVVALYDYQEKSPREVSMKKGDILTLLNSSNKDWWKVEV-NDRQGFVPAAYVKK 53


>gnl|CDD|212795 cd11861, SH3_DLG-like, Src Homology 3 domain of Disks large homolog
           proteins.  The DLG-like proteins are scaffolding
           proteins that cluster at synapses and are also called
           PSD (postsynaptic density)-95 proteins or SAPs
           (synapse-associated proteins). They play important roles
           in synaptic development and plasticity, cell polarity,
           migration and proliferation. They are members of the
           MAGUK (membrane-associated guanylate kinase) protein
           family, which is characterized by the presence of a core
           of three domains: PDZ, SH3, and guanylate kinase (GuK).
           The GuK domain in MAGUK proteins is enzymatically
           inactive; instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. DLG-like proteins contain three PDZ domains
           and varying N-terminal regions. All DLG proteins exist
           as alternatively-spliced isoforms. Vertebrates contain
           four DLG proteins from different genes, called DLG1-4.
           DLG4 and DLG2 are found predominantly at postsynaptic
           sites and they mediate surface ion channel and receptor
           clustering. DLG3 is found axons and some presynaptic
           terminals. DLG1 interacts with AMPA-type glutamate
           receptors and is critical in their maturation and
           delivery to synapses. The SH3 domain of DLG4 binds and
           clusters the kainate subgroup of glutamate receptors via
           two proline-rich sequences in their C-terminal tail. It
           also binds AKAP79/150 (A-kinase anchoring protein). SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 61

 Score = 40.4 bits (95), Expect = 4e-05
 Identities = 20/57 (35%), Positives = 29/57 (50%), Gaps = 10/57 (17%)

Query: 113 VIAKYDFDGNDPDDLP-----FKKNDILIVVSKDEEHWWTAQNIS-----GEVGSIP 159
           V A +D+D +    LP     FK  DIL V +  ++ WW A+ ++      EVG IP
Sbjct: 2   VRALFDYDPSRDSGLPSQGLSFKFGDILHVTNASDDEWWQARRVTPNGEEEEVGVIP 58


>gnl|CDD|198259 cd10396, SH2_Tec_Itk, Src homology 2 (SH2) domain found in Tec
          protein, IL2-inducible T-cell kinase (Itk).  A member
          of the Tec protein tyrosine kinase Itk is expressed
          thymus, spleen, lymph node, T lymphocytes, NK and mast
          cells. It plays a role in T-cell proliferation and
          differentiation, analogous to Tec family kinases Txk.
          Itk  has been shown to interact with Fyn,
          Wiskott-Aldrich syndrome protein, KHDRBS1, PLCG1,
          Lymphocyte cytosolic protein 2, Linker of activated T
          cells, Karyopherin alpha 2, Grb2, and Peptidylprolyl
          isomerase A. Most of the Tec family members have a PH
          domain (Txk and the short (type 1) splice variant of
          Drosophila Btk29A are exceptions), a Tec homology (TH)
          domain, a SH3 domain, a SH2 domain, and a protein
          kinase catalytic domain. The TH domain consists of a
          Zn2+-binding Btk motif and a proline-rich region. The
          Btk motif is found in Tec kinases, Ras GAP, and IGBP.
          It is crucial for the function of Tec PH domains and
          it's lack of presence in Txk is not surprising since it
          lacks a PH domain. The type 1 splice form of the
          Drosophila homolog also lacks both the PH domain and
          the Btk motif. The proline-rich regions are highly
          conserved for the most part with the exception of Bmx
          whose residues surrounding the PXXP motif are not
          conserved (TH-like) and Btk29A  which is entirely
          unique with large numbers of glycine residues
          (TH-extended).  Tec family members all lack a
          C-terminal tyrosine having an autoinhibitory function
          in its phosphorylated state. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 108

 Score = 41.7 bits (98), Expect = 4e-05
 Identities = 27/91 (29%), Positives = 44/91 (48%), Gaps = 8/91 (8%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCV------KENNKVSHYI 62
          D+  WY   + R +A+ +L  E   G F+VRDS+   G Y + +      + N  + HY 
Sbjct: 4  DQYEWYNKNINRSKAEKLLRDEGKEGGFMVRDSSQP-GLYTVSLYTKAGGEGNPCIRHYH 62

Query: 63 INKITNTEQQTCYKIGDKTFSDLPSLLAFYK 93
          I K TN   +  Y      F+ +P L+ ++K
Sbjct: 63 I-KETNDSPKKYYLAEKHVFNSIPELIEYHK 92


>gnl|CDD|212992 cd12059, SH3_MLK1-3, Src Homology 3 domain of Mixed Lineage Kinases
           1, 2, and 3.  MLKs 1, 2, and 3 are Serine/Threonine
           Kinases (STKs), catalyzing the transfer of the
           gamma-phosphoryl group from ATP to S/T residues on
           protein substrates. MLKs act as mitogen-activated
           protein kinase kinase kinases (MAP3Ks, MKKKs, MAPKKKs),
           which phosphorylate and activate MAPK kinases (MAPKKs or
           MKKs or MAP2Ks), which in turn phosphorylate and
           activate MAPKs during signaling cascades that are
           important in mediating cellular responses to
           extracellular signals. MLKs play roles in immunity and
           inflammation, as well as in cell death, proliferation,
           and cell cycle regulation. Little is known about the
           specific function of MLK1, also called MAP3K9. It is
           capable of activating the c-Jun N-terminal kinase
           pathway. Mice lacking both MLK1 and MLK2 are viable,
           fertile, and have normal life spans. MLK2, also called
           MAP3K10, is abundant in brain, skeletal muscle, and
           testis. It functions upstream of the MAPK, c-Jun
           N-terminal kinase. It binds hippocalcin, a
           calcium-sensor protein that protects neurons against
           calcium-induced cell death. Both MLK2 and hippocalcin
           may be associated with the pathogenesis of Parkinson's
           disease. MLK3, also called MAP3K11, is highly expressed
           in breast cancer cells and its signaling through c-Jun
           N-terminal kinase has been implicated in the migration,
           invasion, and malignancy of cancer cells. It also
           functions as a negative regulator of Inhibitor of
           Nuclear Factor-KappaB Kinase (IKK) and thus, impacts
           inflammation and immunity. MLKs contain an SH3 domain, a
           catalytic kinase domain, a leucine zipper, a
           proline-rich region, and a CRIB domain that mediates
           binding to GTP-bound Cdc42 and Rac. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 58

 Score = 40.5 bits (95), Expect = 4e-05
 Identities = 19/54 (35%), Positives = 31/54 (57%), Gaps = 6/54 (11%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKD-----EEHWWTAQNISGEVGSIPVPYV 163
           A +D++ +  D+L  ++ D + V+SKD     +E WWT + I+  VG  P  YV
Sbjct: 4   AVFDYEASAEDELTLRRGDRVEVLSKDSAVSGDEGWWTGK-INDRVGIFPSNYV 56



 Score = 28.6 bits (64), Expect = 0.68
 Identities = 15/51 (29%), Positives = 24/51 (47%), Gaps = 8/51 (15%)

Query: 219 YDKTA---LKLEIGDIIKVTKTNI-----NGQWEGELNGKTGHFPFTHVEF 261
           Y+ +A   L L  GD ++V   +       G W G++N + G FP  +V  
Sbjct: 8   YEASAEDELTLRRGDRVEVLSKDSAVSGDEGWWTGKINDRVGIFPSNYVTS 58


>gnl|CDD|212808 cd11875, SH3_CD2AP-like_3, Third Src Homology 3 domain (SH3C) of
           CD2-associated protein and similar proteins.  This
           subfamily is composed of the third SH3 domain (SH3C) of
           CD2AP, CIN85 (Cbl-interacting protein of 85 kDa), and
           similar domains. CD2AP and CIN85 are adaptor proteins
           that bind to protein partners and assemble complexes
           that have been implicated in T cell activation, kidney
           function, and apoptosis of neuronal cells. They also
           associate with endocytic proteins, actin cytoskeleton
           components, and other adaptor proteins involved in
           receptor tyrosine kinase (RTK) signaling. CD2AP and the
           main isoform of CIN85 contain three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CD2AP and CIN85 to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           SH3C of both proteins have been shown to bind to
           ubiquitin. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 40.0 bits (94), Expect = 4e-05
 Identities = 19/39 (48%), Positives = 24/39 (61%), Gaps = 2/39 (5%)

Query: 224 LKLEIGDIIKV-TKTNIN-GQWEGELNGKTGHFPFTHVE 260
           L L  GDI+ + +K   + G W+GELNGK G FP   VE
Sbjct: 16  LTLREGDIVTILSKDCEDKGWWKGELNGKRGVFPDNFVE 54



 Score = 35.4 bits (82), Expect = 0.002
 Identities = 14/45 (31%), Positives = 28/45 (62%), Gaps = 3/45 (6%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISGEVGSIP 159
           +D++  + D+L  ++ DI+ ++SKD E   WW  + ++G+ G  P
Sbjct: 6   FDYEAENEDELTLREGDIVTILSKDCEDKGWWKGE-LNGKRGVFP 49


>gnl|CDD|212994 cd12061, SH3_betaPIX, Src Homology 3 domain of beta-Pak Interactive
           eXchange factor.  Beta-PIX, also called Rho guanine
           nucleotide exchange factor 7 (ARHGEF7) or Cool (Cloned
           out of Library)-1, activates small GTPases by exchanging
           bound GDP for free GTP. It acts as a GEF for both Cdc42
           and Rac 1, and plays important roles in regulating
           neuroendocrine exocytosis, focal adhesion maturation,
           cell migration, synaptic vesicle localization, and
           insulin secretion. PIX proteins contain an N-terminal
           SH3 domain followed by RhoGEF (also called
           Dbl-homologous or DH) and Pleckstrin Homology (PH)
           domains, and a C-terminal leucine-zipper domain for
           dimerization. The SH3 domain of PIX binds to an atypical
           PxxxPR motif in p21-activated kinases (PAKs) with high
           affinity. The binding of PAKs to PIX facilitate the
           localization of PAKs to focal complexes and also
           localizes PAKs to PIX targets Cdc43 and Rac, leading to
           the activation of PAKs. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 40.1 bits (93), Expect = 4e-05
 Identities = 17/36 (47%), Positives = 21/36 (58%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           L    GD+I VT+    G WEG  NG+TG FP  +V
Sbjct: 16  LSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYV 51



 Score = 38.1 bits (88), Expect = 2e-04
 Identities = 18/53 (33%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           V AK++F   + D+L F K D++ V   +E  WW     +G  G  P  YV++
Sbjct: 2   VRAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEG-THNGRTGWFPSNYVRE 53


>gnl|CDD|212881 cd11948, SH3_GRAP_N, N-terminal Src homology 3 domain of
           GRB2-related adaptor protein.  GRAP is a GRB-2 like
           adaptor protein that is highly expressed in lymphoid
           tissues. It acts as a negative regulator of T cell
           receptor (TCR)-induced lymphocyte proliferation by
           downregulating the signaling to the Ras/ERK pathway. It
           has been identified as a regulator of TGFbeta signaling
           in diabetic kidney tubules and may have a role in the
           pathogenesis of the disease. GRAP contains an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. The N-terminal SH3 domain of the related protein
           GRB2 binds to Sos and Sos-derived proline-rich peptides.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 40.2 bits (94), Expect = 4e-05
 Identities = 19/52 (36%), Positives = 35/52 (67%), Gaps = 2/52 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVS-KDEEHWWTAQNISGEVGSIPVPYVQ 164
           +A Y F   + D+LPF+K DIL +++ +D+++W+ A+ + G  G IP  Y++
Sbjct: 3   VALYSFQATESDELPFQKGDILKILNMEDDQNWYKAE-LQGREGYIPKNYIK 53


>gnl|CDD|212880 cd11947, SH3_GRAP2_N, N-terminal Src homology 3 domain of
           GRB2-related adaptor protein 2.  GRAP2 is also called
           GADS (GRB2-related adapter downstream of Shc), GrpL,
           GRB2L, Mona, or GRID (Grb2-related protein with insert
           domain). It is expressed specifically in the
           hematopoietic system. It plays an important role in T
           cell receptor (TCR) signaling by promoting the formation
           of the SLP-76:LAT complex, which couples the TCR to the
           Ras pathway. It also have roles in antigen-receptor and
           tyrosine kinase mediated signaling. GRAP2 is unique from
           other GRB2-like adaptor proteins in that it can be
           regulated by caspase cleavage. It contains an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. The N-terminal SH3 domain of the related protein
           GRB2 binds to Sos and Sos-derived proline-rich peptides.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 39.8 bits (93), Expect = 5e-05
 Identities = 18/49 (36%), Positives = 29/49 (59%), Gaps = 2/49 (4%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
            K+DF  +  D+L FKK D+L ++S D+   W    ++GE G +P  +V
Sbjct: 4   GKFDFTASGEDELSFKKGDVLKILSSDDI--WFKAELNGEEGYVPKNFV 50


>gnl|CDD|212883 cd11950, SH3_GRAP2_C, C-terminal Src homology 3 domain of
           GRB2-related adaptor protein 2.  GRAP2 is also called
           GADS (GRB2-related adapter downstream of Shc), GrpL,
           GRB2L, Mona, or GRID (Grb2-related protein with insert
           domain). It is expressed specifically in the
           hematopoietic system. It plays an important role in T
           cell receptor (TCR) signaling by promoting the formation
           of the SLP-76:LAT complex, which couples the TCR to the
           Ras pathway. It also has roles in antigen-receptor and
           tyrosine kinase mediated signaling. GRAP2 is unique from
           other GRB2-like adaptor proteins in that it can be
           regulated by caspase cleavage. It contains an N-terminal
           SH3 domain, a central SH2 domain, and a C-terminal SH3
           domain. The C-terminal SH3 domain of GRAP2 binds to
           different motifs found in substrate peptides including
           the typical PxxP motif in hematopoietic progenitor
           kinase 1 (HPK1), the RxxK motif in SLP-76 and HPK1, and
           the RxxxxK motif in phosphatase-like protein HD-PTP. SH3
           domains are protein interaction domains that typically
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 39.8 bits (93), Expect = 5e-05
 Identities = 17/51 (33%), Positives = 27/51 (52%), Gaps = 1/51 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           V A YDF+  + D+L F   D++ V+      WW  + + G++G  P  YV
Sbjct: 2   VRALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGR-LHGKLGLFPANYV 51



 Score = 29.0 bits (65), Expect = 0.39
 Identities = 17/47 (36%), Positives = 24/47 (51%), Gaps = 5/47 (10%)

Query: 219 YDKTA-----LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           YD  A     L    GD+I+V  ++    W+G L+GK G FP  +V 
Sbjct: 6   YDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHGKLGLFPANYVA 52


>gnl|CDD|212715 cd11781, SH3_Sorbs_1, First Src Homology 3 domain of Sorbin and SH3
           domain containing (Sorbs) proteins and similar domains. 
           This family, also called the vinexin family, is composed
           predominantly of adaptor proteins containing one sorbin
           homology (SoHo) and three SH3 domains. Members include
           the first SH3 domains of Sorbs1 (or ponsin), Sorbs2 (or
           ArgBP2), Vinexin (or Sorbs3), and similar domains. They
           are involved in the regulation of cytoskeletal
           organization, cell adhesion, and growth factor
           signaling. Members of this family bind multiple partners
           including signaling molecules like c-Abl, c-Arg, Sos,
           and c-Cbl, as well as cytoskeletal molecules such as
           vinculin and afadin. They may have overlapping
           functions. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 40.0 bits (94), Expect = 5e-05
 Identities = 16/53 (30%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           K  A Y F      +L  KK DI+ +  + +++W+  ++ +G VG  P  YV+
Sbjct: 1   KARALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGEH-NGRVGIFPASYVE 52



 Score = 35.4 bits (82), Expect = 0.002
 Identities = 19/44 (43%), Positives = 26/44 (59%), Gaps = 2/44 (4%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVE 260
           A     L L+ GDII + +  I+  W EGE NG+ G FP ++VE
Sbjct: 10  AQSAKELSLKKGDIIYIRR-QIDKNWYEGEHNGRVGIFPASYVE 52


>gnl|CDD|198273 cd10410, SH2_SH2B1, Src homology 2 (SH2) domain found in SH2B
          adapter proteins (SH2B1, SH2B2, SH2B3).  SH2B1 (SH2-B,
          PSM), like other members of the SH2B adapter protein
          family, contains a pleckstrin homology domain, at least
          one dimerization domain, and a C-terminal SH2 domain
          which binds to phosphorylated tyrosines in a variety of
          tyrosine kinases.  SH2B1 and SH2B2  function in
          signaling pathways found downstream of growth hormone
          receptor and receptor tyrosine kinases, including the
          insulin, insulin-like growth factor-I (IGF-I),
          platelet-derived growth factor (PDGF), nerve growth
          factor, hepatocyte growth factor, and fibroblast growth
          factor receptors. SH2B2beta, a new isoform of SH2B2, is
          an endogenous inhibitor of SH2B1 and/or SH2B2
          (SH2B2alpha), negatively regulating insulin signaling
          and/or JAK2-mediated cellular responses. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 97

 Score = 41.2 bits (96), Expect = 5e-05
 Identities = 26/91 (28%), Positives = 43/91 (47%), Gaps = 6/91 (6%)

Query: 7  PHDRNSWYFGMMTRQEAQAILLS--EKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIIN 64
          P     W+ GM++R +A  ++L      +G FLVR S T  G YVL      K  H    
Sbjct: 4  PLSGYPWFHGMLSRLKAAQLVLEGGTGSHGVFLVRQSETRRGEYVLTFNFQGKAKHL--- 60

Query: 65 KITNTEQQTCYKIGDKTFSDLPSLLAFYKVH 95
          +++  E+  C ++    F  +  +L  ++VH
Sbjct: 61 RLSLNEEGQC-RVQHLWFQSIFDMLEHFRVH 90


>gnl|CDD|198251 cd10388, SH2_SOCS7, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7). In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 41.2 bits (97), Expect = 5e-05
 Identities = 17/49 (34%), Positives = 29/49 (59%), Gaps = 1/49 (2%)

Query: 12 SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSH 60
           WY+G M+ ++A+ +L ++ D G+FLVRDS+     + L  +    V H
Sbjct: 11 GWYWGPMSWEDAEKVLSNKPD-GSFLVRDSSDDRYIFSLSFRSQGSVHH 58


>gnl|CDD|212893 cd11960, SH3_Abp1_eu, Src homology 3 domain of eumetazoan
           Actin-binding protein 1.  Abp1, also called drebrin-like
           protein, is an adaptor protein that functions in
           receptor-mediated endocytosis and vesicle trafficking.
           It contains an N-terminal actin-binding module, the
           actin-depolymerizing factor (ADF) homology domain, a
           helical domain, and a C-terminal SH3 domain. Mammalian
           Abp1, unlike yeast Abp1, does not contain an acidic
           domain that interacts with the Arp2/3 complex. It
           regulates actin dynamics indirectly by interacting with
           dynamin and WASP family proteins. Abp1 deficiency causes
           abnormal organ structure and function of the spleen,
           heart, and lung of mice. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 39.7 bits (93), Expect = 6e-05
 Identities = 15/53 (28%), Positives = 24/53 (45%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +  A YD+   D  ++ F   DI+  + + +E WW      G  G  P  YV+
Sbjct: 1   RARALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGTGPDGTYGLFPANYVE 53


>gnl|CDD|212896 cd11963, SH3_STAM2, Src homology 3 domain of Signal Transducing
           Adaptor Molecule 2.  STAM2, also called EAST (Epidermal
           growth factor receptor-associated protein with SH3 and
           TAM domain) or Hbp (Hrs binding protein), is part of the
           endosomal sorting complex required for transport
           (ESCRT-0). It plays a role in sorting mono-ubiquinated
           endosomal cargo for trafficking to the lysosome for
           degradation. It is also involved in the regulation of
           exocytosis. STAMs were discovered as proteins that are
           highly phosphorylated following cytokine and growth
           factor stimulation. They function in cytokine signaling
           and surface receptor degradation, as well as regulate
           Golgi morphology. They associate with many proteins
           including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and
           UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs,
           STAM homology), ubiquitin interacting (UIM), and SH3
           domains. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 39.6 bits (92), Expect = 6e-05
 Identities = 20/52 (38%), Positives = 31/52 (59%), Gaps = 1/52 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           KV A YDF+  + ++L FK  +I+IV+   + +WW  +N  G VG  P  +V
Sbjct: 3   KVRALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHRG-VGLFPSNFV 53


>gnl|CDD|198250 cd10387, SH2_SOCS6, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7). In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 100

 Score = 41.0 bits (96), Expect = 7e-05
 Identities = 16/32 (50%), Positives = 22/32 (68%), Gaps = 1/32 (3%)

Query: 10 RNSWYFGMMTRQEAQAILLSEKDNGAFLVRDS 41
          +  WY+G +TR EA+  L +  D G+FLVRDS
Sbjct: 9  KQGWYWGPITRWEAEGKLANVPD-GSFLVRDS 39


>gnl|CDD|198214 cd10351, SH2_SH2D4B, Src homology 2 domain found in the SH2
          domain containing protein 4B (SH2D4B).  SH2D4B contains
          a single SH2 domain. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 103

 Score = 41.0 bits (96), Expect = 7e-05
 Identities = 19/52 (36%), Positives = 32/52 (61%), Gaps = 2/52 (3%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIIN 64
          W+ G+++R+EA+A LL     G+FLVR S  I G Y L  +  +   H++++
Sbjct: 9  WFHGIISREEAEA-LLMNATEGSFLVRVSEKIWG-YTLSYRLQSGFKHFLVD 58


>gnl|CDD|213005 cd12072, SH3_FNBP1L, Src Homology 3 domain of Formin Binding
           Protein 1-Like.  FormiN Binding Protein 1-Like (FNBP1L),
           also known as Toca-1 (Transducer of Cdc42-dependent
           actin assembly), forms a complex with neural
           Wiskott-Aldrich syndrome protein (N-WASP). The
           FNBP1L/N-WASP complex induces the formation of filopodia
           and endocytic vesicles. FNBP1L is required for
           Cdc42-induced actin assembly and is essential for
           autophagy of intracellular pathogens. It contains an
           N-terminal F-BAR domain, a central Cdc42-binding HR1
           domain, and a C-terminal SH3 domain. The SH3 domain of
           the related protein, CIP4, associates with Gapex-5, a
           Rab31 GEF. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 39.6 bits (92), Expect = 7e-05
 Identities = 17/51 (33%), Positives = 31/51 (60%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWT-AQNISGEVGSIPVPYVQ 164
           A Y FDG++   L  K+ ++L ++ +D+   WT A+  +GE G +P  Y++
Sbjct: 5   ALYPFDGSNEGTLAMKEGEVLYIIEEDKGDGWTRARKQNGEEGYVPTSYIE 55


>gnl|CDD|212924 cd11991, SH3_Intersectin1_3, Third Src homology 3 domain (or SH3C)
           of Intersectin-1.  Intersectin-1 (ITSN1) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN1 localizes in membranous organelles, CCPs, the
           Golgi complex, and may be involved in the cell membrane
           trafficking system. It exists in alternatively spliced
           short and long isoforms. The short isoform contains two
           Eps15 homology domains (EH1 and EH2), a coiled-coil
           region and five SH3 domains (SH3A-E), while the long
           isoform, in addition, contains RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin homology (PH) and C2
           domains. The third SH3 domain (or SH3C) of ITSN1 has
           been shown to bind many proteins including dynamin1/2,
           CIN85, c-Cbl, SHIP2, Reps1, synaptojanin-1, and WNK,
           among others. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 52

 Score = 39.6 bits (92), Expect = 7e-05
 Identities = 17/51 (33%), Positives = 30/51 (58%), Gaps = 2/51 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +A Y ++ N+  DL F++ D+++V  KD + WWT   +  + G  P  YV+
Sbjct: 3   VAMYTYESNEQGDLTFQQGDVILVTKKDGD-WWTG-TVGDKTGVFPSNYVR 51



 Score = 28.8 bits (64), Expect = 0.43
 Identities = 15/36 (41%), Positives = 20/36 (55%), Gaps = 1/36 (2%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           L  + GD+I VTK +    W G +  KTG FP  +V
Sbjct: 16  LTFQQGDVILVTKKD-GDWWTGTVGDKTGVFPSNYV 50


>gnl|CDD|198261 cd10398, SH2_Tec_Txk, Src homology 2 (SH2) domain found  in Tec
          protein, Txk.  A member of the Tec protein tyrosine
          kinase Txk is expressed in thymus, spleen, lymph node,
          T lymphocytes, NK cells, mast cell lines, and myeloid
          cell line. Txk plays a role in TCR signal transduction,
          T cell development, and selection which is analogous to
          the function of Itk. Txk has been shown to interact
          with IFN-gamma. Unlike most of the Tec family members
          Txk lacks a  PH domain. Instead Txk has a unique region
          containing a palmitoylated cysteine string which has a
          similar membrane tethering function as the PH domain.
          Txk also has a zinc-binding motif, a SH3 domain, a SH2
          domain, and a protein kinase catalytic domain. The TH
          domain consists of a Zn2+-binding Btk motif and a
          proline-rich region. The Btk motif is found in Tec
          kinases, Ras GAP, and IGBP and crucial to the function
          of the PH domain. It is not present in Txk which is not
          surprising since it lacks a PH domain. The type 1
          splice form of the Drosophila homolog also lacks both
          the PH domain and the Btk motif. The proline-rich
          regions are highly conserved for the most part with the
          exception of Bmx whose residues surrounding the PXXP
          motif are not conserved (TH-like) and Btk29A  which is
          entirely unique with large numbers of glycine residues
          (TH-extended).  Tec family members all lack a
          C-terminal tyrosine having an autoinhibitory function
          in its phosphorylated state. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 106

 Score = 40.7 bits (95), Expect = 1e-04
 Identities = 27/88 (30%), Positives = 45/88 (51%), Gaps = 12/88 (13%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNK------VSHYIINKI 66
          WY   +TR +A+ +L  E   GAF+VRDS   LG+Y + V    +      + HY I K 
Sbjct: 8  WYHKNITRNQAERLLRQESKEGAFIVRDSRH-LGSYTISVFTRARRSTEASIKHYQIKK- 65

Query: 67 TNTEQQTCYKIGDK-TFSDLPSLLAFYK 93
           N   Q  + + ++  F  +P L+ +++
Sbjct: 66 -NDSGQ--WYVAERHLFQSIPELIQYHQ 90


>gnl|CDD|212995 cd12062, SH3_Caskin1, Src Homology 3 domain of CASK interacting
           protein 1.  Caskin1 is a multidomain adaptor protein
           that contains six ankyrin repeats, a single SH3 domain,
           tandem sterile alpha motif (SAM) domains, and a long
           disordered proline-rich region. It is expressed at high
           levels in the brain and is localized in presynaptic
           regions. It binds to the multidomain scaffolding protein
           CASK through the CaMK domain in competition with
           Munc-interacting protein 1 (Mint1). CASK participates in
           one of two evolutionarily conserved tripartite complexes
           containing either Mint1 and Velis or Caskin1 and Velis.
           Caskin1 may play a role in infantile myoclonic epilepsy.
           SH3 domains bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs;
           they play a role in the regulation of enzymes by
           intramolecular interactions, changing the subcellular
           localization of signal pathway components and mediate
           multiprotein complex assemblies.
          Length = 62

 Score = 39.2 bits (91), Expect = 1e-04
 Identities = 19/52 (36%), Positives = 32/52 (61%), Gaps = 6/52 (11%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGEL------NGKTGHFPFTHVEFI 262
           N YD T+L ++ GD+I V + + +G+W+G +      N + G+FP + VE I
Sbjct: 11  NNYDLTSLNIKAGDVITVLEQHPDGRWKGCIHDNRTGNDRVGYFPSSLVEAI 62


>gnl|CDD|212852 cd11919, SH3_Sorbs1_1, First Src Homology 3 domain of Sorbin and
           SH3 domain containing 1 (Sorbs1), also called ponsin.
           Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl
           associated protein). It is an adaptor protein containing
           one sorbin homology (SoHo) and three SH3 domains. It
           binds Cbl and plays a major role in regulating the
           insulin signaling pathway by enhancing insulin-induced
           phosphorylation of Cbl. Sorbs1, like vinexin, localizes
           at cell-ECM and cell-cell adhesion sites where it binds
           vinculin, paxillin, and afadin. It may function in the
           control of cell motility. Other interaction partners of
           Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7,
           filamin C, among others. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 39.2 bits (91), Expect = 1e-04
 Identities = 15/50 (30%), Positives = 29/50 (58%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           AK+DF      +LP +K DI+ +  + +++W+  ++  G VG  P  Y++
Sbjct: 5   AKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEGEH-HGRVGIFPRSYIE 53



 Score = 32.2 bits (73), Expect = 0.031
 Identities = 14/39 (35%), Positives = 24/39 (61%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEFI 262
           L L+ GDI+ + K      +EGE +G+ G FP +++E +
Sbjct: 17  LPLQKGDIVYIYKQIDQNWYEGEHHGRVGIFPRSYIELL 55


>gnl|CDD|212968 cd12035, SH3_MPP1-like, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 1 (or MAGUK p55 subfamily member 1)-like
           proteins.  This subfamily includes MPP1, CASK
           (Calcium/calmodulin-dependent Serine protein Kinase),
           Caenorhabditis elegans lin-2, and similar proteins. MPP1
           and CASK are scaffolding proteins from the MAGUK
           (membrane-associated guanylate kinase) protein family,
           which is characterized by the presence of a core of
           three domains: PDZ, SH3, and guanylate kinase (GuK). In
           addition, they also have the Hook (Protein 4.1 Binding)
           motif in between the SH3 and GuK domains. The GuK domain
           in MAGUK proteins is enzymatically inactive; instead,
           the domain mediates protein-protein interactions and
           associates intramolecularly with the SH3 domain. CASK
           and lin-2 also contain an N-terminal
           calmodulin-dependent kinase (CaMK)-like domain and two
           L27 domains. MPP1 is ubiquitously-expressed and plays
           roles in regulating neutrophil polarity, cell shape,
           hair cell development, and neural development and
           patterning of the retina. CASK is highly expressed in
           the mammalian nervous system and plays roles in synaptic
           protein targeting, neural development, and gene
           expression regulation. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 62

 Score = 39.3 bits (92), Expect = 1e-04
 Identities = 22/60 (36%), Positives = 31/60 (51%), Gaps = 12/60 (20%)

Query: 113 VIAKYDFDGNDPDDL--------PFKKNDILIVVSKDEEHWWTAQNISGE---VGSIPVP 161
           V A++D+D +  DDL         FK  DIL ++SKD+ +WW A+         G IP P
Sbjct: 2   VRAQFDYDPSK-DDLIPCQQAGIAFKTGDILQIISKDDHNWWQARKPGASKEPAGLIPSP 60


>gnl|CDD|212798 cd11864, SH3_PEX13_eumet, Src Homology 3 domain of eumetazoan
           Peroxisomal biogenesis factor 13.  PEX13 is a peroxin
           and is required for protein import into the peroxisomal
           matrix and membrane. It is an integral membrane protein
           that is essential for the localization of PEX14 and the
           import of proteins containing the peroxisome matrix
           targeting signals, PTS1 and PTS2. Mutations of the PEX13
           gene in humans lead to a wide range of peroxisome
           biogenesis disorders (PBDs), the most severe of which is
           known as Zellweger syndrome (ZS), a severe multisystem
           disorder characterized by hypotonia, psychomotor
           retardation, and neuronal migration defects. PEX13
           contains two transmembrane regions and a C-terminal SH3
           domain. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 39.2 bits (92), Expect = 1e-04
 Identities = 16/55 (29%), Positives = 26/55 (47%), Gaps = 4/55 (7%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEH----WWTAQNISGEVGSIPVPYVQ 164
            A+YDF     D+L F+  D L +  K+ +     W  A     ++G +P  YV+
Sbjct: 3   RAEYDFVAESEDELSFRAGDKLRLAPKELQPRVRGWLLATVDGQKIGLVPANYVK 57


>gnl|CDD|198225 cd10362, SH2_Src_Lck, Src homology 2 (SH2) domain in lymphocyte
          cell kinase (Lck).  Lck is a member of the Src
          non-receptor type tyrosine kinase family of proteins.
          It is expressed in the brain, T-cells, and NK cells.
          The unique domain of Lck mediates its interaction with
          two T-cell surface molecules, CD4 and CD8. It
          associates with their cytoplasmic tails on CD4 T helper
          cells  and CD8 cytotoxic T cells to assist signaling
          from the T cell receptor (TCR) complex. When the T cell
          receptor is engaged by the specific antigen presented
          by MHC, Lck phosphorylase the intracellular chains of
          the CD3 and zeta-chains of the TCR complex, allowing
          ZAP-70 to bind them. Lck then phosphorylates and
          activates ZAP-70, which in turn phosphorylates Linker
          of Activated T cells (LAT), a transmembrane protein
          that serves as a docking site for proteins including:
          Shc-Grb2-SOS, PI3K, and phospholipase C (PLC). The
          tyrosine phosphorylation cascade culminates in the
          intracellular mobilization of a calcium ions and
          activation of important signaling cascades within the
          lymphocyte, including the Ras-MEK-ERK pathway, which
          goes on to activate certain transcription factors such
          as NFAT, NF-kappaB, and AP-1. These transcription
          factors regulate the production cytokines such as
          Interleukin-2 that promote long-term proliferation and
          differentiation of the activated lymphocytes.  The
          N-terminal tail of Lck is myristoylated and
          palmitoylated and it tethers the protein to the plasma
          membrane of the cell. Lck also contains a SH3 domain, a
          SH2 domain, and a C-terminal tyrosine kinase domain.
          Lck has 2 phosphorylation sites, the first an
          autophosphorylation site that is linked to activation
          of the protein and the second which is phosphorylated
          by Csk, which inhibits it. Lck is also inhibited by
          SHP-1 dephosphorylation and by Cbl ubiquitin ligase,
          which is part of the ubiquitin-mediated pathway. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 40.2 bits (94), Expect = 1e-04
 Identities = 27/86 (31%), Positives = 46/86 (53%), Gaps = 9/86 (10%)

Query: 13 WYFGMMTRQEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNK-----VSHYIINKI 66
          W+F  ++R +A+  LL+  + +G+FL+R+S T  G++ L V++ ++     V HY   KI
Sbjct: 5  WFFKNLSRNDAERQLLAPGNTHGSFLIRESETTAGSFSLSVRDFDQNQGEVVKHY---KI 61

Query: 67 TNTEQQTCYKIGDKTFSDLPSLLAFY 92
           N +    Y     TF  L  L+  Y
Sbjct: 62 RNLDNGGFYISPRITFPGLHELVRHY 87


>gnl|CDD|212695 cd11761, SH3_FCHSD_1, First Src Homology 3 domain of FCH and double
           SH3 domains proteins.  This group is composed of FCH and
           double SH3 domains protein 1 (FCHSD1) and FCHSD2. These
           proteins have a common domain structure consisting of an
           N-terminal F-BAR (FES-CIP4 Homology and
           Bin/Amphiphysin/Rvs), two SH3, and C-terminal
           proline-rich domains. They have only been characterized
           in silico and their functions remain unknown. This group
           also includes the insect protein, nervous wreck, which
           acts as a regulator of synaptic growth signaling. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 38.9 bits (91), Expect = 1e-04
 Identities = 18/50 (36%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSK-DEEHWWTAQNISGEVGSIPVPYVQK 165
           Y ++   PD+L   + + L V+   D + W  A+N SGEVG +P  Y+Q 
Sbjct: 8   YSYEAQRPDELTITEGEELEVIEDGDGDGWVKARNKSGEVGYVPENYLQF 57


>gnl|CDD|212892 cd11959, SH3_Cortactin, Src homology 3 domain of Cortactin.
           Cortactin was originally identified as a substrate of
           Src kinase. It is an actin regulatory protein that binds
           to the Arp2/3 complex and stabilizes branched actin
           filaments. It is involved in cellular processes that
           affect cell motility, adhesion, migration, endocytosis,
           and invasion. It is expressed ubiquitously except in
           hematopoietic cells, where the homolog hematopoietic
           lineage cell-specific 1 (HS1) is expressed instead.
           Cortactin contains an N-terminal acidic domain, several
           copies of a repeat domain found in cortactin and HS1, a
           proline-rich region, and a C-terminal SH3 domain. The
           N-terminal region interacts with the Arp2/3 complex and
           F-actin, and is crucial in regulating branched actin
           assembly. Cortactin also serves as a scaffold and
           provides a bridge to the actin cytoskeleton for membrane
           trafficking and signaling proteins that bind to its SH3
           domain. Binding partners for the SH3 domain of cortactin
           include dynamin2, N-WASp, MIM, FGD1, among others. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 38.6 bits (90), Expect = 1e-04
 Identities = 16/51 (31%), Positives = 26/51 (50%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +A YD+   D D++ F  +DI+  +   +E WW      G+ G  P  YV+
Sbjct: 3   VALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGV-CRGKYGLFPANYVE 52



 Score = 29.7 bits (67), Expect = 0.22
 Identities = 18/47 (38%), Positives = 21/47 (44%), Gaps = 8/47 (17%)

Query: 218 AYDKTALKLEIGDIIKVTKTNI----NGQWEGELNGKTGHFPFTHVE 260
           A D   +  +  DII    TNI     G W G   GK G FP  +VE
Sbjct: 10  AADDDEISFDPDDII----TNIEMIDEGWWRGVCRGKYGLFPANYVE 52


>gnl|CDD|212832 cd11899, SH3_Nck2_1, First Src Homology 3 domain of Nck2 adaptor
           protein.  Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4) plays a crucial role in
           connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds neuronal signaling
           proteins such as ephrinB and Disabled-1 (Dab-1)
           exclusively. Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2, which show partly overlapping functions but also
           bind distinct targets. The first SH3 domain of Nck2
           binds the PxxDY sequence in the CD3e cytoplasmic tail;
           this binding inhibits phosphorylation by Src kinases,
           resulting in the downregulation of TCR surface
           expression. SH3 domains are protein interaction domains
           that usually bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially a PxxP motif.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 58

 Score = 38.6 bits (89), Expect = 2e-04
 Identities = 18/53 (33%), Positives = 30/53 (56%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           VIAK+D+      +L  KKN+ L ++  D + WW  +N +   G +P  YV++
Sbjct: 6   VIAKWDYTAQQDQELDIKKNERLWLLD-DSKTWWRVRNAANRTGYVPSNYVER 57


>gnl|CDD|212905 cd11972, SH3_Abi2, Src homology 3 domain of Abl Interactor 2.  Abi2
           is highly expressed in the brain and eye. It regulates
           actin cytoskeletal reorganization at adherens junctions
           and dendritic spines, which is important in cell
           morphogenesis, migration, and cognitive function. Mice
           deficient with Abi2 show defects in orientation and
           migration of lens fibers, neuronal migration, dendritic
           spine morphology, as well as deficits in learning and
           memory. Abi proteins are adaptor proteins serving as
           binding partners and substrates of Abl tyrosine kinases.
           They are involved in regulating actin cytoskeletal
           reorganization and play important roles in
           membrane-ruffling, endocytosis, cell motility, and cell
           migration. Abi proteins contain a homeobox homology
           domain, a proline-rich region, and a SH3 domain. The SH3
           domain of Abi binds to a PxxP motif in Abl. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 61

 Score = 38.5 bits (89), Expect = 2e-04
 Identities = 18/58 (31%), Positives = 34/58 (58%), Gaps = 1/58 (1%)

Query: 110 IEKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQKYS 167
           +EKV+A YD+  +  D+L F++  I+ V+ K+++ W+    ++G  G  P  YV+   
Sbjct: 2   LEKVVAIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGV-MNGVTGLFPGNYVESIM 58



 Score = 35.8 bits (82), Expect = 0.002
 Identities = 19/39 (48%), Positives = 24/39 (61%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEFI 262
           L  + G II V K N +G +EG +NG TG FP  +VE I
Sbjct: 19  LSFQEGAIIYVIKKNDDGWYEGVMNGVTGLFPGNYVESI 57


>gnl|CDD|212987 cd12054, SH3_CD2AP_2, Second Src Homology 3 domain (SH3B) of
           CD2-associated protein.  CD2AP, also called CMS (Cas
           ligand with Multiple SH3 domains) or METS1
           (Mesenchyme-to-Epithelium Transition protein with SH3
           domains), is a cytosolic adaptor protein that plays a
           role in regulating the cytoskeleton. It is critical in
           cell-to-cell union necessary for kidney function. It
           also stabilizes the contact between a T cell and
           antigen-presenting cells. It is primarily expressed in
           podocytes at the cytoplasmic face of the slit diaphragm
           and serves as a linker anchoring podocin and nephrin to
           the actin cytoskeleton. CD2AP contains three SH3
           domains, a proline-rich region, and a C-terminal
           coiled-coil domain. All of these domains enable CD2AP to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           This alignment model represents the second SH3 domain
           (SH3B) of CD2AP. SH3B binds to c-Cbl in a site (TPSSRPLR
           is the core binding motif) distinct from the c-Cbl/SH3A
           binding site. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 38.4 bits (89), Expect = 2e-04
 Identities = 20/46 (43%), Positives = 28/46 (60%), Gaps = 2/46 (4%)

Query: 215 VPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           VP   D+  L+L++GDII + +    G W G LNGK+G FP   V+
Sbjct: 10  VPQNEDE--LELKVGDIIDINEEVEEGWWSGTLNGKSGLFPSNFVK 53



 Score = 30.3 bits (68), Expect = 0.12
 Identities = 13/49 (26%), Positives = 27/49 (55%), Gaps = 1/49 (2%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +++   + D+L  K  DI+ +  + EE WW+    +G+ G  P  +V++
Sbjct: 7   FEYVPQNEDELELKVGDIIDINEEVEEGWWSGTL-NGKSGLFPSNFVKE 54


>gnl|CDD|212751 cd11817, SH3_Eve1_4, Fourth Src homology 3 domain of ADAM-binding
           protein Eve-1.  Eve-1, also called SH3 domain-containing
           protein 19 (SH3D19) or EEN-binding protein (EBP), exists
           in multiple alternatively spliced isoforms. The longest
           isoform contains five SH3 domain in the C-terminal
           region and seven proline-rich motifs in the N-terminal
           region. It is abundantly expressed in skeletal muscle
           and heart, and may be involved in regulating the
           activity of ADAMs (A disintegrin and metalloproteases).
           Eve-1 interacts with EEN, an endophilin involved in
           endocytosis and may be the target of the MLL-EEN fusion
           protein that is implicated in leukemogenesis. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 50

 Score = 38.2 bits (89), Expect = 2e-04
 Identities = 14/50 (28%), Positives = 25/50 (50%), Gaps = 1/50 (2%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPY 162
            +A YDF G   +DL F++ D ++V    +  W   + ++G  G  P  +
Sbjct: 2   AVALYDFTGETEEDLSFQRGDRILVTEHLDAEWSRGR-LNGREGIFPRAF 50



 Score = 27.8 bits (62), Expect = 0.98
 Identities = 17/43 (39%), Positives = 24/43 (55%), Gaps = 7/43 (16%)

Query: 219 YDKTA-----LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFP 255
           YD T      L  + GD I VT+ +++ +W  G LNG+ G FP
Sbjct: 6   YDFTGETEEDLSFQRGDRILVTE-HLDAEWSRGRLNGREGIFP 47


>gnl|CDD|212837 cd11904, SH3_Nck1_3, Third Src Homology 3 domain of Nck1 adaptor
           protein.  Nck1 (also called Nckalpha) plays a crucial
           role in connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds and activates RasGAP,
           resulting in the downregulation of Ras. It is also
           involved in the signaling of endothilin-mediated
           inhibition of cell migration. Nck adaptor proteins
           regulate actin cytoskeleton dynamics by linking
           proline-rich effector molecules to protein tyrosine
           kinases and phosphorylated signaling intermediates. They
           contain three SH3 domains and a C-terminal SH2 domain.
           They function downstream of the PDGFbeta receptor and
           are involved in Rho GTPase signaling and actin dynamics.
           Vertebrates contain two Nck adaptor proteins: Nck1 (also
           called Nckalpha) and Nck2, which show partly overlapping
           functions but also bind distinct targets. The third SH3
           domain of Nck appears to prefer ligands with a PxAPxR
           motif. SH3 domains are protein interaction domains that
           usually bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially a PxxP motif.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 38.5 bits (89), Expect = 2e-04
 Identities = 18/53 (33%), Positives = 31/53 (58%), Gaps = 2/53 (3%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEE--HWWTAQNISGEVGSIPVPYV 163
           V A Y F  ++ ++L F+K +++ V+ K E    WW  +  +G+VG +P  YV
Sbjct: 3   VQALYPFSSSNDEELNFEKGEVMDVIEKPENDPEWWKCRKANGQVGLVPKNYV 55


>gnl|CDD|212886 cd11953, SH3_ASPP2, Src Homology 3 (SH3) domain of Apoptosis
           Stimulating of p53 protein 2.  ASPP2 is the full length
           form of the previously-identified tumor supressor,
           p53-binding protein 2 (p53BP2). ASPP2 activates the
           apoptotic function of the p53 family of tumor
           suppressors (p53, p63, and p73). It plays a central role
           in regulating apoptosis and cell growth; ASPP2-deficient
           mice show postnatal death. Downregulated expression of
           ASPP2 is frequently found in breast tumors, lung cancer,
           and diffuse large B-cell lymphoma where it is correlated
           with a poor clinical outcome. ASPP2 contains a
           proline-rich region, four ankyrin (ANK) repeats, and an
           SH3 domain at its C-terminal half. The SH3 domain and
           the ANK repeats of ASPP2 contribute to the p53 binding
           site; they bind to the DNA binding domain of p53. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 38.4 bits (89), Expect = 2e-04
 Identities = 17/50 (34%), Positives = 28/50 (56%), Gaps = 4/50 (8%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSK---DEEHWWTAQNISGEVGSIP 159
           V A +D++G   D+L FK+ D + ++ +   DE  WW A+    E G +P
Sbjct: 3   VYALWDYEGESDDELSFKEGDCMTILRREDEDETEWWWARLNDKE-GYVP 51


>gnl|CDD|212830 cd11897, SH3_SNX18, Src Homology 3 domain of Sorting nexin 18.
           SNX18 is localized to peripheral endosomal structures,
           and acts in a trafficking pathway that is
           clathrin-independent but relies on AP-1 and PACS1. It
           binds FIP5 and is required for apical lumen formation.
           It may also play a role in axonal elongation. SNXs are
           Phox homology (PX) domain containing proteins that are
           involved in regulating membrane traffic and protein
           sorting in the endosomal system. SNX18 also contains BAR
           and SH3 domains. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 38.0 bits (88), Expect = 2e-04
 Identities = 16/51 (31%), Positives = 28/51 (54%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVS-KDEEHWWTAQNISGEVGSIPVPYVQ 164
           A YDF   +P ++  +++++L + S +D E W    N  G+ G  P  YV+
Sbjct: 4   ALYDFRSENPGEISLREHEVLSLCSEQDIEGWLEGVNSRGDRGLFPASYVE 54


>gnl|CDD|212731 cd11797, SH3_DNMBP_N4, Fourth N-terminal Src homology 3 domain of
           Dynamin Binding Protein, also called Tuba.  DNMBP or
           Tuba is a cdc42-specific guanine nucleotide exchange
           factor (GEF) that contains four N-terminal SH3 domains,
           a central RhoGEF [or Dbl homology (DH)] domain followed
           by a Bin/Amphiphysin/Rvs (BAR) domain, and two
           C-terminal SH3 domains. It provides a functional link
           between dynamin and key regulatory proteins of the actin
           cytoskeleton. It plays an important role in regulating
           cell junction configuration. The four N-terminal SH3
           domains of DNMBP bind the GTPase dynamin, which plays an
           important role in the fission of endocytic vesicles. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 50

 Score = 37.8 bits (88), Expect = 2e-04
 Identities = 16/39 (41%), Positives = 22/39 (56%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPF 256
           A +   L  E+GD I++  T  +G  EGEL G+ G FP 
Sbjct: 10  ALEPNELDFEVGDRIRIIATLEDGWLEGELKGRRGIFPH 48


>gnl|CDD|212750 cd11816, SH3_Eve1_3, Third Src homology 3 domain of ADAM-binding
           protein Eve-1.  Eve-1, also called SH3 domain-containing
           protein 19 (SH3D19) or EEN-binding protein (EBP), exists
           in multiple alternatively spliced isoforms. The longest
           isoform contains five SH3 domain in the C-terminal
           region and seven proline-rich motifs in the N-terminal
           region. It is abundantly expressed in skeletal muscle
           and heart, and may be involved in regulating the
           activity of ADAMs (A disintegrin and metalloproteases).
           Eve-1 interacts with EEN, an endophilin involved in
           endocytosis and may be the target of the MLL-EEN fusion
           protein that is implicated in leukemogenesis. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 51

 Score = 38.2 bits (89), Expect = 2e-04
 Identities = 14/50 (28%), Positives = 30/50 (60%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +A++DF+G   D+L F + D++ +     E W   + ++G++G  P+ +V
Sbjct: 3   VARFDFEGEQEDELSFSEGDVITLKEYVGEEWAKGE-LNGKIGIFPLNFV 51



 Score = 32.4 bits (74), Expect = 0.021
 Identities = 16/37 (43%), Positives = 21/37 (56%), Gaps = 2/37 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHV 259
           L    GD+I + K  +  +W +GELNGK G FP   V
Sbjct: 16  LSFSEGDVITL-KEYVGEEWAKGELNGKIGIFPLNFV 51


>gnl|CDD|212771 cd11837, SH3_Intersectin_2, Second Src homology 3 domain (or SH3B)
           of Intersectin.  Intersectins (ITSNs) are adaptor
           proteins that function in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction.
           They are essential for initiating clathrin-coated pit
           formation. They bind to many proteins through their
           multidomain structure and facilitate the assembly of
           multimeric complexes. Vertebrates contain two ITSN
           proteins, ITSN1 and ITSN2, which exist in alternatively
           spliced short and long isoforms. The short isoforms
           contain two Eps15 homology domains (EH1 and EH2), a
           coiled-coil region and five SH3 domains (SH3A-E), while
           the long isoforms, in addition, contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin homology (PH)
           and C2 domains. ITSN1 and ITSN2 are both widely
           expressed, with variations depending on tissue type and
           stage of development. The second SH3 domain (or SH3B) of
           ITSN1 has been shown to bind WNK and CdGAP. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 38.1 bits (89), Expect = 2e-04
 Identities = 17/53 (32%), Positives = 24/53 (45%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
              A Y +     + L F K DI+ V+ + E  WW  +   GE G  P  YV+
Sbjct: 1   TATALYPWRAKKENHLSFAKGDIITVLEQQEM-WWFGELEGGEEGWFPKSYVK 52


>gnl|CDD|212910 cd11977, SH3_VAV2_2, C-terminal (or second) Src homology 3 domain
           of VAV2 protein.  VAV2 is widely expressed and functions
           as a guanine nucleotide exchange factor (GEF) for RhoA,
           RhoB and RhoG and also activates Rac1 and Cdc42. It is
           implicated in many cellular and physiological functions
           including blood pressure control, eye development,
           neurite outgrowth and branching, EGFR endocytosis and
           degradation, and cell cluster morphology, among others.
           It has been reported to associate with Nek3. VAV
           proteins contain several domains that enable their
           function: N-terminal calponin homology (CH), acidic,
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           Homology (PH), C1 (zinc finger), SH2, and two SH3
           domains. The SH3 domain of VAV is involved in the
           localization of proteins to specific sites within the
           cell, by interacting with proline-rich sequences within
           target proteins. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 58

 Score = 38.1 bits (88), Expect = 2e-04
 Identities = 18/45 (40%), Positives = 25/45 (55%), Gaps = 2/45 (4%)

Query: 218 AYDKTALKLEIGDIIKVTKT--NINGQWEGELNGKTGHFPFTHVE 260
           A D   L L  GD++++        G W+GE NG+ G FP T+VE
Sbjct: 11  ARDMRELSLREGDVVRIYSRIGGDQGWWKGETNGRIGWFPSTYVE 55



 Score = 35.0 bits (80), Expect = 0.003
 Identities = 14/54 (25%), Positives = 31/54 (57%), Gaps = 3/54 (5%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSK--DEEHWWTAQNISGEVGSIPVPYVQK 165
           +A+Y+F   D  +L  ++ D++ + S+   ++ WW  +  +G +G  P  YV++
Sbjct: 4   VARYNFAARDMRELSLREGDVVRIYSRIGGDQGWWKGET-NGRIGWFPSTYVEE 56


>gnl|CDD|212857 cd11924, SH3_Vinexin_2, Second Src Homology 3 domain of Vinexin,
           also called Sorbin and SH3 domain containing 3 (Sorbs3).
            Vinexin is also called Sorbs3, SH3P3, and
           SH3-containing adapter molecule 1 (SCAM-1). It is an
           adaptor protein containing one sorbin homology (SoHo)
           and three SH3 domains. Vinexin was first identified as a
           vinculin binding protein; it is co-localized with
           vinculin at cell-ECM and cell-cell adhesion sites. There
           are several splice variants of vinexin: alpha, which
           contains the SoHo and three SH3 domains and displays
           tissue-specific expression; and beta, which contains
           only the three SH3 domains and is widely expressed.
           Vinexin alpha stimulates the accumulation of F-actin at
           focal contact sites. Vinexin also promotes keratinocyte
           migration and wound healing. The SH3 domains of vinexin
           have been reported to bind a number of ligands including
           vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 56

 Score = 38.0 bits (88), Expect = 2e-04
 Identities = 17/53 (32%), Positives = 30/53 (56%), Gaps = 3/53 (5%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISG--EVGSIPVPYVQ 164
           +A+Y F G+   +L F+K + + ++ K  E+W+  + I+G    G  P  YVQ
Sbjct: 4   VAQYTFKGDLEVELSFRKGEHICLIRKVNENWYEGR-ITGTGRQGIFPASYVQ 55


>gnl|CDD|212762 cd11828, SH3_ARHGEF9_like, Src homology 3 domain of ARHGEF9-like
           Rho guanine nucleotide exchange factors.  Members of
           this family contain a SH3 domain followed by RhoGEF
           (also called Dbl-homologous or DH) and Pleckstrin
           Homology (PH) domains. They include the Rho guanine
           nucleotide exchange factors ARHGEF9, ASEF (also called
           ARHGEF4), ASEF2, and similar proteins. GEFs activate
           small GTPases by exchanging bound GDP for free GTP.
           ARHGEF9 specifically activates Cdc42, while both ASEF
           and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly
           expressed in the brain and it interacts with gephyrin, a
           postsynaptic protein associated with GABA and glycine
           receptors. ASEF plays a role in angiogenesis and cell
           migration. ASEF2 is important in cell migration and
           adhesion dynamics. ASEF exists in an autoinhibited form
           and is activated upon binding of the tumor suppressor
           APC (adenomatous polyposis coli), leading to the
           activation of Rac1 or Cdc42. In its autoinhibited form,
           the SH3 domain of ASEF forms an extensive interface with
           the DH and PH domains, blocking the Rac binding site.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 37.7 bits (88), Expect = 3e-04
 Identities = 16/53 (30%), Positives = 26/53 (49%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
              A +D    DP++L FK  D++ V+   ++ WW    I  E G  P  +V+
Sbjct: 1   LAEALWDHVTMDPEELGFKAGDVIEVLDMSDKDWWWGS-IRDEEGWFPASFVR 52



 Score = 31.2 bits (71), Expect = 0.068
 Identities = 12/43 (27%), Positives = 19/43 (44%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
              D   L  + GD+I+V   +    W G +  + G FP + V
Sbjct: 9   VTMDPEELGFKAGDVIEVLDMSDKDWWWGSIRDEEGWFPASFV 51


>gnl|CDD|212978 cd12045, SH3_SKAP2, Src Homology 3 domain of Src Kinase-Associated
           Phosphoprotein 2.  SKAP2, also called SKAP55-Related
           (SKAP55R) or SKAP55 homolog (SKAP-HOM or SKAP55-HOM), is
           an immune cell-specific adaptor protein that plays an
           important role in adhesion and migration of B-cells and
           macrophages. Binding partners include ADAP (adhesion and
           degranulation-promoting adaptor protein), YopH, SHPS1,
           and HPK1. SKAP2 has also been identified as a substrate
           for lymphoid-specific tyrosine phosphatase (Lyp), which
           has been implicated in a wide variety of autoimmune
           diseases. It contains a pleckstrin homology (PH) domain,
           a C-terminal SH3 domain, and several tyrosine
           phosphorylation sites. Like SKAP1, SKAP2 is expected to
           bind primarily to a proline-rich region of ADAP through
           its SH3 domain; its degradation may be regulated by
           ADAP. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 38.0 bits (88), Expect = 3e-04
 Identities = 16/49 (32%), Positives = 29/49 (59%), Gaps = 3/49 (6%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISGEVGSIPVPYV 163
           +D  G+ PD+L FK+ D + ++SK+     WW  + + G +G +P  Y+
Sbjct: 6   WDCTGDQPDELSFKRGDTIYILSKEYNRFGWWVGE-MKGTIGLVPKAYI 53


>gnl|CDD|198285 cd10718, SH2_CIS, Src homology 2 (SH2) domain found in
          cytokine-inducible SH2-containing protein (CIS).  CIS
          family members are known to be cytokine-inducible
          negative regulators of cytokine signaling. The
          expression of the CIS gene can be induced by IL2, IL3,
          GM-CSF and EPO in hematopoietic cells.
          Proteasome-mediated degradation of this protein has
          been shown to be involved in the inactivation of the
          erythropoietin receptor. Suppressor of cytokine
          signalling (SOCS) was first recognized as a group of
          cytokine-inducible SH2 (CIS) domain proteins comprising
          eight family members in human (CIS and SOCS1-SOCS7).
          In addition to the SH2 domain, SOCS proteins have a
          variable N-terminal domain and a conserved SOCS box in
          the C-terminal domain. SOCS proteins bind to a
          substrate via their SH2 domain. The prototypical
          members, CIS and SOCS1-SOCS3, have been shown to
          regulate growth hormone signaling in vitro and in a
          classic negative feedback response compete for binding
          at phosphotyrosine sites in JAK kinase and receptor
          pathways to displace effector proteins and target bound
          receptors for proteasomal degradation. Loss of SOCS
          activity results in excessive cytokine signaling
          associated with a variety of hematopoietic, autoimmune,
          and inflammatory diseases and certain cancers. In
          general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 88

 Score = 38.6 bits (90), Expect = 3e-04
 Identities = 23/91 (25%), Positives = 37/91 (40%), Gaps = 12/91 (13%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKI-- 66
            + WY+G +T  EA   L  +   G FLVRDS+       L VK     ++  I     
Sbjct: 2  RESGWYWGSITASEAHQALQ-KAPEGTFLVRDSSHPSYMLTLSVKTTRGPTNVRIEYSDG 60

Query: 67 -----TNTEQQTCYKIGDKTFSDLPSLLAFY 92
               +++  +        +F D+ SL+  Y
Sbjct: 61 SFRLDSSSLARPRL----LSFPDVVSLVQHY 87


>gnl|CDD|212863 cd11930, SH3_SH3RF1_2, Second Src Homology 3 domain of SH3 domain
           containing ring finger protein 1, an E3
           ubiquitin-protein ligase.  SH3RF1 is also called POSH
           (Plenty of SH3s) or SH3MD2 (SH3 multiple domains protein
           2). It is a scaffold protein that acts as an E3
           ubiquitin-protein ligase. It plays a role in calcium
           homeostasis through the control of the ubiquitin domain
           protein Herp. It may also have a role in regulating
           death receptor mediated and JNK mediated apoptosis.
           SH3RF1 also enhances the ubiquitination of ROMK1
           potassium channel resulting in its increased
           endocytosis. It contains an N-terminal RING finger
           domain and four SH3 domains. This model represents the
           second SH3 domain, located C-terminal of the first SH3
           domain at the N-terminal half, of SH3RF1. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 37.7 bits (87), Expect = 3e-04
 Identities = 22/54 (40%), Positives = 33/54 (61%), Gaps = 7/54 (12%)

Query: 115 AKYDFDGNDP----DDLPFKKNDILIVVSKDEEHWWTAQNISGE-VGSIPVPYV 163
           A YDF+  D     D LPF K+DIL V+ + +E+W  A+ + G+ +G  P+ YV
Sbjct: 4   ALYDFEVKDKEADKDCLPFAKDDILTVIRRVDENW--AEGMLGDKIGIFPISYV 55


>gnl|CDD|212899 cd11966, SH3_ASAP2, Src homology 3 domain of ArfGAP with SH3
           domain, ankyrin repeat and PH domain containing protein
           2.  ASAP2 is also called DDEF2 (Development and
           Differentiation Enhancing Factor 2), AMAP2, centaurin
           beta-3, or PAG3. It mediates the functions of Arf
           GTPases vial dual mechanisms: it exhibits GTPase
           activating protein (GAP) activity towards class I (Arf1)
           and II (Arf5) Arfs; and it binds class III Arfs
           (GTP-Arf6) stably without GAP activity. It binds
           paxillin and is implicated in Fcgamma receptor-mediated
           phagocytosis in macrophages and in cell migration. ASAP2
           contains an N-terminal BAR domain, followed by a
           Pleckstrin homology (PH) domain, an Arf GAP domain,
           ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 38.0 bits (88), Expect = 3e-04
 Identities = 19/56 (33%), Positives = 34/56 (60%), Gaps = 4/56 (7%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEV---GSIPVPYVQ 164
           +V A Y+   ++PD+L F + +I+IV  ++++ WW   +I GE    G+ PV +V 
Sbjct: 1   RVKALYNCVADNPDELTFSEGEIIIVDGEEDKEWWIG-HIDGEPTRRGAFPVSFVH 55


>gnl|CDD|212813 cd11880, SH3_Caskin, Src Homology 3 domain of CASK interacting
           protein.  Caskin proteins are multidomain adaptor
           proteins that contain six ankyrin repeats, a single SH3
           domain, tandem sterile alpha motif (SAM) domains, and a
           long disordered proline-rich region. There are two
           Caskin proteins called Caskin1 and Caskin2. Caskin1
           binds to the multidomain scaffolding protein CASK
           through the CaM domain in competition with
           Munc-interacting protein 1 (Mint1). CASK participates in
           one of two evolutionarily conserved tripartite complexes
           containing either Mint1 and Velis or Caskin1 and Velis.
           Caskin1 may play a role in infantile myoclonic epilepsy.
           There is not much known about Caskin2; despite sharing a
           domain architecture with Caskin1, Caskin2 does not bind
           CASK. SH3 domains bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially to
           PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 61

 Score = 37.9 bits (88), Expect = 3e-04
 Identities = 19/50 (38%), Positives = 30/50 (60%), Gaps = 6/50 (12%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGEL------NGKTGHFPFTHVE 260
           N +D TAL +  GDII V + + +G+W+G +      N + G+FP + VE
Sbjct: 11  NNHDLTALNVRAGDIITVLEQHPDGRWKGHIHDNQTGNDRVGYFPPSLVE 60


>gnl|CDD|212833 cd11900, SH3_Nck1_1, First Src Homology 3 domain of Nck1 adaptor
           protein.  Nck1 (also called Nckalpha) plays a crucial
           role in connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds and activates RasGAP,
           resulting in the downregulation of Ras. It is also
           involved in the signaling of endothilin-mediated
           inhibition of cell migration. Nck adaptor proteins
           regulate actin cytoskeleton dynamics by linking
           proline-rich effector molecules to protein tyrosine
           kinases and phosphorylated signaling intermediates. They
           contain three SH3 domains and a C-terminal SH2 domain.
           They function downstream of the PDGFbeta receptor and
           are involved in Rho GTPase signaling and actin dynamics.
           Vertebrates contain two Nck adaptor proteins: Nck1 (also
           called Nckalpha) and Nck2, which show partly overlapping
           functions but also bind distinct targets. The first SH3
           domain of Nck1 binds the PxxDY sequence in the CD3e
           cytoplasmic tail; this binding inhibits phosphorylation
           by Src kinases, resulting in the downregulation of TCR
           surface expression. SH3 domains are protein interaction
           domains that usually bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially a PxxP
           motif. They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 59

 Score = 37.8 bits (87), Expect = 3e-04
 Identities = 17/53 (32%), Positives = 30/53 (56%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           V+AK+D+      +L  KKN+ L ++  D + WW  +N   + G +P  YV++
Sbjct: 5   VVAKFDYVAQQDQELDIKKNERLWLLD-DSKSWWRVRNAMNKTGFVPSNYVER 56


>gnl|CDD|212727 cd11793, SH3_ephexin1_like, Src homology 3 domain of ephexin-1-like
           SH3 domain containing Rho guanine nucleotide exchange
           factors.  Members of this family contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin Homology (PH),
           and C-terminal SH3 domains. They include the Rho guanine
           nucleotide exchange factors ARHGEF5, ARHGEF16, ARHGEF19,
           ARHGEF26, ARHGEF27 (also called ephexin-1), and similar
           proteins, and are also called ephexins because they
           interact directly with ephrin A receptors. GEFs interact
           with Rho GTPases via their DH domains to catalyze
           nucleotide exchange by stabilizing the nucleotide-free
           GTPase intermediate. They play important roles in
           neuronal development. The SH3 domains of ARHGEFs play an
           autoinhibitory role through intramolecular interactions
           with a proline-rich region N-terminal to the DH domain.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 37.3 bits (87), Expect = 5e-04
 Identities = 19/55 (34%), Positives = 30/55 (54%), Gaps = 5/55 (9%)

Query: 212 QVRVPNAYDKT---ALKLEIGDIIKVTKTNINGQWEGE--LNGKTGHFPFTHVEF 261
           QV+  +AY       L LE GD++ V +   +G +EGE   +G+ G FP ++ E 
Sbjct: 1   QVQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGERLRDGERGWFPSSYTEE 55



 Score = 30.0 bits (68), Expect = 0.18
 Identities = 13/53 (24%), Positives = 26/53 (49%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNIS-GEVGSIPVPYVQ 164
           V   + +    PD+L  ++ D++ V+ K  + W+  + +  GE G  P  Y +
Sbjct: 2   VQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGERLRDGERGWFPSSYTE 54


>gnl|CDD|212897 cd11964, SH3_STAM1, Src homology 3 domain of Signal Transducing
           Adaptor Molecule 1.  STAM1 is part of the endosomal
           sorting complex required for transport (ESCRT-0) and is
           involved in sorting ubiquitinated cargo proteins from
           the endosome. It may also be involved in the regulation
           of IL2 and GM-CSF mediated signaling, and has been
           implicated in neural cell survival. STAMs were
           discovered as proteins that are highly phosphorylated
           following cytokine and growth factor stimulation. They
           function in cytokine signaling and surface receptor
           degradation, as well as regulate Golgi morphology. They
           associate with many proteins including Jak2 and Jak3
           tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor
           proteins contain VHS (Vps27, Hrs, STAM homology),
           ubiquitin interacting (UIM), and SH3 domains. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 36.9 bits (85), Expect = 6e-04
 Identities = 17/52 (32%), Positives = 28/52 (53%), Gaps = 1/52 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           KV A YDF+  + ++L FK  DI+ ++   + +WW  +   G  G  P  +V
Sbjct: 2   KVRAIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGETPQG-TGLFPSNFV 52



 Score = 25.7 bits (56), Expect = 6.1
 Identities = 14/42 (33%), Positives = 19/42 (45%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           A +   L  + GDII +   +    W+GE    TG FP   V
Sbjct: 11  AAEDNELTFKAGDIITILDDSDPNWWKGETPQGTGLFPSNFV 52


>gnl|CDD|212985 cd12052, SH3_CIN85_1, First Src Homology 3 domain (SH3A) of
           Cbl-interacting protein of 85 kDa.  CIN85, also called
           SH3 domain-containing kinase-binding protein 1 (SH3KBP1)
           or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor
           protein that is involved in the downregulation of
           receptor tyrosine kinases by facilitating endocytosis
           through interaction with endophilin-associated ubiquitin
           ligase Cbl proteins. It is also important in many other
           cellular processes including vesicle-mediated transport,
           cytoskeletal remodelling, apoptosis, cell adhesion and
           migration, and viral infection, among others. CIN85
           exists as multiple variants from alternative splicing;
           the main variant contains three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CIN85 to bind
           various protein partners and assemble complexes that
           have been implicated in many different functions. This
           alignment model represents the first SH3 domain (SH3A)
           of CIN85; SH3A binds to internal proline-rich motifs
           within the proline-rich region. This intramolecular
           interaction serves as a regulatory mechanism to keep
           CIN85 in a closed conformation, preventing the
           recruitment of other proteins. SH3A has also been shown
           to bind ubiquitin and to an atypical PXXXPR motif at the
           C-terminus of Cbl and the cytoplasmic end of the cell
           adhesion protein CD2. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 36.8 bits (85), Expect = 6e-04
 Identities = 15/32 (46%), Positives = 20/32 (62%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           L + +GDII   K +  G WEGE+ G+ G FP
Sbjct: 16  LTITVGDIITKIKKDDGGWWEGEIKGRRGLFP 47



 Score = 33.3 bits (76), Expect = 0.011
 Identities = 15/52 (28%), Positives = 26/52 (50%), Gaps = 1/52 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           I ++D+     D+L     DI+  + KD+  WW  + I G  G  P  +V++
Sbjct: 3   IVEFDYKAQHEDELTITVGDIITKIKKDDGGWWEGE-IKGRRGLFPDNFVRE 53


>gnl|CDD|212723 cd11789, SH3_Nebulin_family_C, C-terminal Src Homology 3 domain of
           the Nebulin family of proteins.  Nebulin family proteins
           contain multiple nebulin repeats, and may contain an
           N-terminal LIM domain and/or a C-terminal SH3 domain.
           They have molecular weights ranging from 34 to 900 kD,
           depending on the number of nebulin repeats, and they all
           bind actin. They are involved in the regulation of actin
           filament architecture and function as stabilizers and
           scaffolds for cytoskeletal structures with which they
           associate, such as long actin filaments or focal
           adhesions. Nebulin family proteins that contain a
           C-terminal SH3 domain include the giant filamentous
           protein nebulin, nebulette, Lasp1, and Lasp2. Lasp2,
           also called LIM-nebulette, is an alternatively spliced
           variant of nebulette. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 36.5 bits (85), Expect = 7e-04
 Identities = 15/55 (27%), Positives = 29/55 (52%), Gaps = 1/55 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYVQK 165
           +  A YD+   D D++ F++ D++I V   ++ W       +G+ G +P  YV+ 
Sbjct: 1   RYRAMYDYAAADDDEVSFQEGDVIINVEIIDDGWMEGTVQRTGQSGMLPANYVEL 55


>gnl|CDD|213006 cd12073, SH3_HS1, Src homology 3 domain of Hematopoietic lineage
           cell-specific protein 1.  HS1, also called HCLS1
           (hematopoietic cell-specific Lyn substrate 1), is a
           cortactin homolog expressed specifically in
           hematopoietic cells. It is an actin regulatory protein
           that binds the Arp2/3 complex and stabilizes branched
           actin filaments. It is required for cell spreading and
           signaling in lymphocytes. It regulates cytoskeletal
           remodeling that controls lymphocyte trafficking, and it
           also affects tissue invasion and infiltration of
           leukemic B cells. Like cortactin, HS1 contains an
           N-terminal acidic domain, several copies of a repeat
           domain found in cortactin and HS1, a proline-rich
           region, and a C-terminal SH3 domain. The N-terminal
           region binds the Arp2/3 complex and F-actin, while the
           C-terminal region acts as an adaptor or scaffold that
           can connect varied proteins that bind the SH3 domain
           within the actin network. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 36.7 bits (85), Expect = 7e-04
 Identities = 14/51 (27%), Positives = 23/51 (45%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +A YD+ G   D++ F   + +  +   +E WW      G  G  P  YV+
Sbjct: 4   VALYDYQGEGDDEISFDPQETITDIEMVDEGWWKGT-CHGHRGLFPANYVE 53


>gnl|CDD|212996 cd12063, SH3_Caskin2, Src Homology 3 domain of CASK interacting
           protein 2.  Caskin2 is a multidomain adaptor protein
           that contains six ankyrin repeats, a single SH3 domain,
           tandem sterile alpha motif (SAM) domains, and a long
           disordered proline-rich region. It shares a domain
           architecture with Caskin1, but does not bind CASK. The
           function of Caskin2 is still unknown. SH3 domains bind
           to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs; they play a
           role in the regulation of enzymes by intramolecular
           interactions, changing the subcellular localization of
           signal pathway components and mediate multiprotein
           complex assemblies.
          Length = 62

 Score = 36.9 bits (85), Expect = 7e-04
 Identities = 18/52 (34%), Positives = 31/52 (59%), Gaps = 6/52 (11%)

Query: 217 NAYDKTALKLEIGDIIKVTKTNINGQWEGELN------GKTGHFPFTHVEFI 262
           N +D TAL +  GD+I V + + +G+W+G ++       + G+FP + VE I
Sbjct: 11  NLHDPTALNVRAGDVITVLEQHPDGRWKGHIHDSQRGTDRVGYFPPSIVEVI 62


>gnl|CDD|212696 cd11762, SH3_FCHSD_2, Second Src Homology 3 domain of FCH and
           double SH3 domains proteins.  This group is composed of
           FCH and double SH3 domains protein 1 (FCHSD1) and
           FCHSD2. These proteins have a common domain structure
           consisting of an N-terminal F-BAR (FES-CIP4 Homology and
           Bin/Amphiphysin/Rvs), two SH3, and C-terminal
           proline-rich domains. They have only been characterized
           in silico and their functions remain unknown. This group
           also includes the insect protein, nervous wreck, which
           acts as a regulator of synaptic growth signaling. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 36.6 bits (85), Expect = 8e-04
 Identities = 16/36 (44%), Positives = 21/36 (58%), Gaps = 4/36 (11%)

Query: 229 GDIIKVTKTNIN----GQWEGELNGKTGHFPFTHVE 260
           G II++ + + N    G WEGE NG+ G FP   VE
Sbjct: 21  GAIIRILRKDDNGVDDGWWEGEFNGRVGVFPSLVVE 56



 Score = 33.1 bits (76), Expect = 0.014
 Identities = 14/49 (28%), Positives = 26/49 (53%), Gaps = 5/49 (10%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDE----EHWWTAQNISGEVGSIP 159
           A YD++    ++L F +  I+ ++ KD+    + WW  +  +G VG  P
Sbjct: 4   ALYDYEAQSDEELSFPEGAIIRILRKDDNGVDDGWWEGE-FNGRVGVFP 51


>gnl|CDD|212972 cd12039, SH3_MPP3, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 3 (or MAGUK p55 subfamily member 3).  MPP3
           is a scaffolding protein that colocalizes with MPP5 and
           CRB1 at the subdpical region adjacent to adherens
           junctions and may function in photoreceptor polarity. It
           interacts with some nectins and regulates their
           trafficking and processing. Nectins are cell-cell
           adhesion proteins involved in the establishment
           apical-basal polarity at cell adhesion sites. It is one
           of seven vertebrate homologs of the Drosophila Stardust
           protein, which is required in establishing cell
           polarity, and it contains two L27 domains followed by
           the core of three domains characteristic of MAGUK
           (membrane-associated guanylate kinase) proteins: PDZ,
           SH3, and guanylate kinase (GuK). The GuK domain in MAGUK
           proteins is enzymatically inactive; instead, the domain
           mediates protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 62

 Score = 36.9 bits (85), Expect = 8e-04
 Identities = 14/25 (56%), Positives = 19/25 (76%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNI 151
           LPFK+ DIL VVS+D+  WW A+ +
Sbjct: 23  LPFKRRDILEVVSQDDPTWWQAKRV 47


>gnl|CDD|212815 cd11882, SH3_GRAF-like, Src Homology 3 domain of GTPase Regulator
           Associated with Focal adhesion kinase and similar
           proteins.  This subfamily is composed of Rho GTPase
           activating proteins (GAPs) with similarity to GRAF.
           Members contain an N-terminal BAR domain, followed by a
           Pleckstrin homology (PH) domain, a Rho GAP domain, and a
           C-terminal SH3 domain. Although vertebrates harbor four
           Rho GAPs in the GRAF subfamily including GRAF, GRAF2,
           GRAF3, and Oligophrenin-1 (OPHN1), only three are
           included in this model. OPHN1 contains the BAR, PH and
           GAP domains, but not the C-terminal SH3 domain. GRAF and
           GRAF2 show GAP activity towards RhoA and Cdc42. GRAF
           influences Rho-mediated cytoskeletal rearrangements and
           binds focal adhesion kinase. GRAF2 regulates
           caspase-activated p21-activated protein kinase-2. The
           SH3 domain of GRAF and GRAF2 binds PKNbeta, a target of
           the small GTPase Rho. SH3 domains bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs; they play a role in the
           regulation of enzymes by intramolecular interactions,
           changing the subcellular localization of signal pathway
           components and mediate multiprotein complex assemblies.
          Length = 54

 Score = 36.1 bits (84), Expect = 0.001
 Identities = 15/53 (28%), Positives = 23/53 (43%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +  A Y     D  +L F+   I+  V   +E  W    ++G  G IP  YV+
Sbjct: 1   RARALYACKAEDESELSFEPGQIITNVQPSDEPGWLEGTLNGRTGLIPENYVE 53



 Score = 35.7 bits (83), Expect = 0.001
 Identities = 20/45 (44%), Positives = 26/45 (57%), Gaps = 1/45 (2%)

Query: 218 AYDKTALKLEIGDIIK-VTKTNINGQWEGELNGKTGHFPFTHVEF 261
           A D++ L  E G II  V  ++  G  EG LNG+TG  P  +VEF
Sbjct: 10  AEDESELSFEPGQIITNVQPSDEPGWLEGTLNGRTGLIPENYVEF 54


>gnl|CDD|198234 cd10371, SH2_Src_Blk, Src homology 2 (SH2) domain found in B
          lymphoid kinase (Blk).  Blk is a member of the Src
          non-receptor type tyrosine kinase family of proteins.
          Blk is expressed in the B-cells. Unlike most other Src
          members Blk lacks cysteine residues in the SH4 domain
          that undergo palmitylation. Blk is required for the
          development of IL-17-producing gamma-delta T cells.
          Furthermore, Blk is expressed in lymphoid precursors
          and, in this capacity, plays a role in regulating
          thymus cellularity during ontogeny. Blk has a unique
          N-terminal domain, an SH3 domain, an SH2 domain, a
          kinase domain and a regulatory tail, as do the other
          members of the family. In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 100

 Score = 37.3 bits (86), Expect = 0.001
 Identities = 26/85 (30%), Positives = 44/85 (51%), Gaps = 8/85 (9%)

Query: 13 WYFGMMTRQEAQAILLSEKDN-GAFLVRDSNTILGNYVLCVK----ENNKVSHYIINKIT 67
          W+F  ++R++A+  LL+  +  G+FL+R+S +  G + L VK    +   V HY   KI 
Sbjct: 5  WFFRTISRKDAERQLLAPMNKAGSFLIRESESNKGAFSLSVKDVTTQGEVVKHY---KIR 61

Query: 68 NTEQQTCYKIGDKTFSDLPSLLAFY 92
          + +    Y     TF  L +L+  Y
Sbjct: 62 SLDNGGYYISPRITFPTLQALVQHY 86


>gnl|CDD|212977 cd12044, SH3_SKAP1, Src Homology 3 domain of Src Kinase-Associated
           Phosphoprotein 1.  SKAP1, also called SKAP55 (Src
           kinase-associated protein of 55kDa), is an immune
           cell-specific adaptor protein that plays an important
           role in T-cell adhesion, migration, and integrin
           clustering. It is expressed exclusively in
           T-lymphocytes, mast cells, and macrophages. Binding
           partners include ADAP (adhesion and
           degranulation-promoting adaptor protein), Fyn, Riam,
           RapL, and RasGRP. It contains a pleckstrin homology (PH)
           domain, a C-terminal SH3 domain, and several tyrosine
           phosphorylation sites. The SH3 domain of SKAP1 is
           necessary for its ability to regulate T-cell conjugation
           with antigen-presenting cells and the formation of LFA-1
           clusters. SKAP1 binds primarily to a proline-rich region
           of ADAP through its SH3 domain; its degradation is
           regulated by ADAP. A secondary interaction occurs via
           the ADAP SH3 domain and the RKxxYxxY motif in SKAP1. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 36.0 bits (83), Expect = 0.001
 Identities = 16/49 (32%), Positives = 32/49 (65%), Gaps = 3/49 (6%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEH--WWTAQNISGEVGSIPVPYV 163
           +D  G++PD+L F++ D++ ++SK+     WW  + ++G VG +P  Y+
Sbjct: 6   WDCFGDNPDELSFQRGDLIYILSKEYNMYGWWVGE-LNGIVGIVPKDYL 53



 Score = 27.9 bits (62), Expect = 1.1
 Identities = 14/34 (41%), Positives = 18/34 (52%), Gaps = 2/34 (5%)

Query: 224 LKLEIGDIIKVTKT--NINGQWEGELNGKTGHFP 255
           L  + GD+I +     N+ G W GELNG  G  P
Sbjct: 16  LSFQRGDLIYILSKEYNMYGWWVGELNGIVGIVP 49


>gnl|CDD|212885 cd11952, SH3_iASPP, Src Homology 3 (SH3) domain of Inhibitor of
           ASPP protein (iASPP).  iASPP, also called
           RelA-associated inhibitor (RAI), is an oncoprotein that
           inhibits the apoptotic transactivation potential of p53.
           It is upregulated in human breast cancers expressing
           wild-type p53, in acute leukemias regardless of the p53
           mutation status, as well as in ovarian cancer where it
           is associated with poor patient outcome and
           chemoresistance. iASPP is also a binding partner and
           negative regulator of p65RelA, which promotes cell
           proliferation and inhibits apoptosis; p65RelA has the
           opposite effect on cell growth compared to the p53
           family. It contains a proline-rich region, four ankyrin
           (ANK) repeats, and an SH3 domain at its C-terminal half.
           The SH3 domain and the ANK repeats of iASPP contribute
           to the p53 binding site; they bind to the DNA binding
           domain of p53. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 56

 Score = 36.1 bits (83), Expect = 0.001
 Identities = 19/52 (36%), Positives = 29/52 (55%), Gaps = 3/52 (5%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKD--EEHWWTAQNISGEVGSIPVPY 162
           V A +D+    PD+L FK+ D++ V+ KD     WW A ++ G  G +P  Y
Sbjct: 3   VYALWDYSAEFPDELSFKEGDMVTVLRKDGEGTDWWWA-SLCGREGYVPRNY 53


>gnl|CDD|212925 cd11992, SH3_Intersectin2_3, Third Src homology 3 domain (or SH3C)
           of Intersectin-2.  Intersectin-2 (ITSN2) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN2 also functions as a specific GEF for Cdc42
           activation in epithelial morphogenesis, and is required
           in mitotic spindle orientation. It exists in
           alternatively spliced short and long isoforms. The short
           isoform contains two Eps15 homology domains (EH1 and
           EH2), a coiled-coil region and five SH3 domains
           (SH3A-E), while the long isoform, in addition, contains
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           homology (PH) and C2 domains. The third SH3 domain
           (SH3C) of ITSN2 has been shown to bind the K15 protein
           of Kaposi's sarcoma-associated herpesvirus. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 35.8 bits (82), Expect = 0.001
 Identities = 19/51 (37%), Positives = 27/51 (52%), Gaps = 2/51 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           IA Y +  ++P DL F + + ++V  KD E WWT   I    G  P  YV+
Sbjct: 3   IALYPYSSSEPGDLTFNEGEEILVTQKDGE-WWTGS-IEDRTGIFPSNYVR 51


>gnl|CDD|198262 cd10399, SH2_Tec_Bmx, Src homology 2 (SH2) domain found  in Tec
          protein, Bmx.  A member of the Tec protein tyrosine
          kinase Bmx is expressed in the endothelium of large
          arteries, fetal endocardium, adult endocardium of the
          left ventricle, bone marrow, lung, testis,
          granulocytes, myeloid cell lines, and prostate cell
          lines. Bmx is involved in the regulation of Rho and
          serum response factor (SRF). Bmx has been shown to
          interact with PAK1, PTK2, PTPN21, and RUFY1. Most of
          the Tec family members have a PH domain (Txk and the
          short (type 1) splice variant of Drosophila Btk29A are
          exceptions), a Tec homology (TH) domain, a SH3 domain,
          a SH2 domain, and a protein kinase catalytic domain.
          The TH domain consists of a Zn2+-binding Btk motif and
          a proline-rich region. The Btk motif is found in Tec
          kinases, Ras GAP, and IGBP.  It is crucial for the
          function of Tec PH domains. It is not present in Txk
          and the type 1 splice form of the Drosophila homolog.
          The proline-rich regions are highly conserved for the
          most part with the exception of Bmx whose residues
          surrounding the PXXP motif are not conserved (TH-like)
          and Btk29A  which is entirely unique with large numbers
          of glycine residues (TH-extended). Tec family members
          all lack a C-terminal tyrosine having an autoinhibitory
          function in its phosphorylated state. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 106

 Score = 37.2 bits (86), Expect = 0.001
 Identities = 25/91 (27%), Positives = 48/91 (52%), Gaps = 10/91 (10%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNY---VLCVKENNK---VSHYI 62
          D   W+ G ++R +++ +L  +   GAF+VR+S+ + G Y   +     N+K   V HY 
Sbjct: 4  DAYDWFAGNISRSQSEQLLRQKGKEGAFMVRNSSQV-GMYTVSLFSKAVNDKKGTVKHYH 62

Query: 63 INKITNTEQQTCYKIGDKTFSDLPSLLAFYK 93
          ++  TN E +  Y   +  F  +P L+ +++
Sbjct: 63 VH--TNAENKL-YLAENYCFDSIPKLIHYHQ 90


>gnl|CDD|212767 cd11833, SH3_Stac_1, First C-terminal Src homology 3 domain of SH3
           and cysteine-rich domain-containing (Stac) proteins.
           Stac proteins are putative adaptor proteins that contain
           a cysteine-rich C1 domain and one or two SH3 domains at
           the C-terminus. There are three mammalian members
           (Stac1, Stac2, and Stac3) of this family. Stac1 and
           Stac3 contain two SH3 domains while Stac2 contains a
           single SH3 domain at the C-terminus. This model
           represents the first C-terminal SH3 domain of Stac1 and
           Stac3, and the single C-terminal SH3 domain of Stac2.
           Stac1 and Stac2 have been found to be expressed
           differently in mature dorsal root ganglia (DRG) neurons.
           Stac1 is mainly expressed in peptidergic neurons while
           Stac2 is found in a subset of nonpeptidergic and all
           trkB+ neurons. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 35.9 bits (83), Expect = 0.001
 Identities = 15/52 (28%), Positives = 25/52 (48%), Gaps = 1/52 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +A Y F   + +DL  +  D + ++    E WW  + I   VG  P  +VQ+
Sbjct: 3   VALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKGK-IEDRVGFFPANFVQR 53


>gnl|CDD|212719 cd11785, SH3_SH3RF_C, C-terminal (Fourth) Src Homology 3 domain of
           SH3 domain containing ring finger 1 (SH3RF1), SH3RF3,
           and similar domains.  SH3RF1 (or POSH) and SH3RF3 (or
           POSH2) are scaffold proteins that function as E3
           ubiquitin-protein ligases. They contain an N-terminal
           RING finger domain and four SH3 domains. This model
           represents the fourth SH3 domain, located at the
           C-terminus of SH3RF1 and SH3RF3, and similar domains.
           SH3RF1 plays a role in calcium homeostasis through the
           control of the ubiquitin domain protein Herp. It may
           also have a role in regulating death receptor mediated
           and JNK mediated apoptosis. SH3RF3 interacts with
           p21-activated kinase 2 (PAK2) and GTP-loaded Rac1. It
           may play a role in regulating JNK mediated apoptosis in
           certain conditions. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 35.9 bits (83), Expect = 0.001
 Identities = 18/39 (46%), Positives = 25/39 (64%), Gaps = 2/39 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGEL--NGKTGHFPFTHVE 260
           L+L+ GDI+ V K   +G ++G L   GKTG FP + VE
Sbjct: 16  LELKEGDIVFVHKKREDGWFKGTLQRTGKTGLFPGSFVE 54


>gnl|CDD|212790 cd11856, SH3_p47phox_like, Src homology 3 domains of the p47phox
           subunit of NADPH oxidase and similar domains.  This
           family is composed of the tandem SH3 domains of p47phox
           subunit of NADPH oxidase and Nox Organizing protein 1
           (NoxO1), the four SH3 domains of Tks4 (Tyr kinase
           substrate with four SH3 domains), the five SH3 domains
           of Tks5, the SH3 domain of obscurin, Myosin-I,  and
           similar domains. Most members of this group also contain
           Phox homology (PX) domains, except for obscurin and
           Myosin-I. p47phox and NoxO1 are regulators of the
           phagocytic NADPH oxidase complex (also called Nox2 or
           gp91phox) and nonphagocytic NADPH oxidase Nox1,
           respectively. They play roles in the activation of their
           respective NADPH oxidase, which catalyzes the transfer
           of electrons from NADPH to molecular oxygen to form
           superoxide. Tks proteins are Src substrates and
           scaffolding proteins that play important roles in the
           formation of podosomes and invadopodia, the dynamic
           actin-rich structures that are related to cell migration
           and cancer cell invasion. Obscurin is a giant muscle
           protein that plays important roles in the organization
           and assembly of the myofibril and the sarcoplasmic
           reticulum. Type I myosins (Myosin-I) are actin-dependent
           motors in endocytic actin structures and actin patches.
           They play roles in membrane traffic in endocytic and
           secretory pathways, cell motility, and mechanosensing.
           Myosin-I contains an N-terminal actin-activated ATPase,
           a phospholipid-binding TH1 (tail homology 1) domain, and
           a C-terminal extension which includes an F-actin-binding
           TH2 domain, an SH3 domain, and an acidic peptide that
           participates in activating the Arp2/3complex. The SH3
           domain of myosin-I is required for myosin-I-induced
           actin polymerization. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 35.7 bits (83), Expect = 0.002
 Identities = 10/52 (19%), Positives = 28/52 (53%), Gaps = 1/52 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +A  D++    D++  ++ +++ V+ K++  WW  +    + G +P  Y++ 
Sbjct: 3   VAIADYEAQGDDEISLQEGEVVEVLEKNDSGWWYVR-KGDKEGWVPASYLEP 53



 Score = 28.0 bits (63), Expect = 0.78
 Identities = 10/41 (24%), Positives = 21/41 (51%)

Query: 220 DKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
               + L+ G++++V + N +G W      K G  P +++E
Sbjct: 12  GDDEISLQEGEVVEVLEKNDSGWWYVRKGDKEGWVPASYLE 52


>gnl|CDD|212986 cd12053, SH3_CD2AP_1, First Src Homology 3 domain (SH3A) of
           CD2-associated protein.  CD2AP, also called CMS (Cas
           ligand with Multiple SH3 domains) or METS1
           (Mesenchyme-to-Epithelium Transition protein with SH3
           domains), is a cytosolic adaptor protein that plays a
           role in regulating the cytoskeleton. It is critical in
           cell-to-cell union necessary for kidney function. It
           also stabilizes the contact between a T cell and
           antigen-presenting cells. It is primarily expressed in
           podocytes at the cytoplasmic face of the slit diaphragm
           and serves as a linker anchoring podocin and nephrin to
           the actin cytoskeleton. CD2AP contains three SH3
           domains, a proline-rich region, and a C-terminal
           coiled-coil domain. All of these domains enable CD2AP to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           This alignment model represents the first SH3 domain
           (SH3A) of CD2AP. SH3A binds to the PXXXPR motif present
           in c-Cbl and the cytoplasmic domain of cell adhesion
           protein CD2. Its interaction with CD2 anchors CD2 at
           sites of cell contact. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 56

 Score = 35.6 bits (82), Expect = 0.002
 Identities = 17/40 (42%), Positives = 24/40 (60%), Gaps = 1/40 (2%)

Query: 217 NAYDKTALKLEIGDIIK-VTKTNINGQWEGELNGKTGHFP 255
           +A  +  L + +G+II+ V K    G  EGELNG+ G FP
Sbjct: 9   DAVHEDELTIRVGEIIRNVKKLEEEGWLEGELNGRRGMFP 48



 Score = 33.7 bits (77), Expect = 0.010
 Identities = 16/54 (29%), Positives = 28/54 (51%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           + I +YD+D    D+L  +  +I+  V K EE  W    ++G  G  P  +V++
Sbjct: 1   EYIVEYDYDAVHEDELTIRVGEIIRNVKKLEEEGWLEGELNGRRGMFPDNFVKE 54


>gnl|CDD|212819 cd11886, SH3_BOI, Src Homology 3 domain of fungal BOI-like
           proteins.  This subfamily includes the Saccharomyces
           cerevisiae proteins BOI1 and BOI2, and similar proteins.
           They contain an N-terminal SH3 domain, a Sterile alpha
           motif (SAM), and a Pleckstrin homology (PH) domain at
           the C-terminus. BOI1 and BOI2 interact with the SH3
           domain of Bem1p, a protein involved in bud formation.
           They promote polarized cell growth and participates in
           the NoCut signaling pathway, which is involved in the
           control of cytokinesis. SH3 domains bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs; they play a role in the
           regulation of enzymes by intramolecular interactions,
           changing the subcellular localization of signal pathway
           components and mediate multiprotein complex assemblies.
          Length = 55

 Score = 35.4 bits (82), Expect = 0.002
 Identities = 17/54 (31%), Positives = 28/54 (51%), Gaps = 4/54 (7%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH---WWTAQN-ISGEVGSIPVPY 162
           +I  +DF+    D+L  K  D + ++  DEE    W+  +N  +GE G  PV +
Sbjct: 2   LIVIHDFNARSEDELTLKPGDKIELIEDDEEFGDGWYLGRNLRTGETGLFPVVF 55


>gnl|CDD|212862 cd11929, SH3_SH3RF2_1, First Src Homology 3 domain of SH3 domain
           containing ring finger 2.  SH3RF2 is also called POSHER
           (POSH-eliminating RING protein) or HEPP1 (heart protein
           phosphatase 1-binding protein). It acts as an
           anti-apoptotic regulator of the JNK pathway by binding
           to and promoting the degradation of SH3RF1 (or POSH), a
           scaffold protein that is required for pro-apoptotic JNK
           activation. It may also play a role in cardiac functions
           together with protein phosphatase 1. SH3RF2 contains an
           N-terminal RING finger domain and three SH3 domains.
           This model represents the first SH3 domain, located at
           the N-terminal half, of SH3RF2. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 35.7 bits (82), Expect = 0.002
 Identities = 15/50 (30%), Positives = 30/50 (60%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A  ++ G++P DL F K D++++  + +E+W+  + I+G  G  P   V+
Sbjct: 5   ALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGE-INGVSGIFPASSVE 53



 Score = 28.0 bits (62), Expect = 1.00
 Identities = 14/37 (37%), Positives = 21/37 (56%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           LK   GD+I + +      + GE+NG +G FP + VE
Sbjct: 17  LKFNKGDVILLRRQLDENWYLGEINGVSGIFPASSVE 53


>gnl|CDD|212967 cd12034, SH3_MPP4, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 4 (or MAGUK p55 subfamily member 4).
           MPP4, also called Disks Large homolog 6 (DLG6) or
           Amyotrophic lateral sclerosis 2 chromosomal region
           candidate gene 5 protein (ALS2CR5), is a retina-specific
           scaffolding protein that plays a role in organizing
           presynaptic protein complexes in the photoreceptor
           synapse, where it localizes to the plasma membrane. It
           is required in the proper localization of calcium
           ATPases and for maintenance of calcium homeostasis. MPP4
           is one of seven vertebrate homologs of the Drosophila
           Stardust protein, which is required in establishing cell
           polarity, and it contains two L27 domains followed by
           the core of three domains characteristic of MAGUK
           (membrane-associated guanylate kinase) proteins: PDZ,
           SH3, and guanylate kinase (GuK). The GuK domain in MAGUK
           proteins is enzymatically inactive; instead, the domain
           mediates protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 61

 Score = 35.6 bits (82), Expect = 0.002
 Identities = 12/26 (46%), Positives = 19/26 (73%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNIS 152
           LPF+K DIL +V +++  WW A+ +S
Sbjct: 23  LPFRKGDILQIVDQNDSLWWQARKLS 48


>gnl|CDD|212770 cd11836, SH3_Intersectin_1, First Src homology 3 domain (or SH3A)
           of Intersectin.  Intersectins (ITSNs) are adaptor
           proteins that function in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction.
           They are essential for initiating clathrin-coated pit
           formation. They bind to many proteins through their
           multidomain structure and facilitate the assembly of
           multimeric complexes. Vertebrates contain two ITSN
           proteins, ITSN1 and ITSN2, which exist in alternatively
           spliced short and long isoforms. The short isoforms
           contain two Eps15 homology domains (EH1 and EH2), a
           coiled-coil region and five SH3 domains (SH3A-E), while
           the long isoforms, in addition, contain RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin homology (PH)
           and C2 domains. ITSN1 and ITSN2 are both widely
           expressed, with variations depending on tissue type and
           stage of development. The first SH3 domain (or SH3A) of
           ITSN1 has been shown to bind many proteins including
           Sos1, dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP,
           and CdGAP, among others. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 35.4 bits (82), Expect = 0.002
 Identities = 18/52 (34%), Positives = 27/52 (51%), Gaps = 1/52 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDE-EHWWTAQNISGEVGSIPVPYVQK 165
           A Y F+  +PD++ F+  DI+ V      E  W A  + G+ G  P  YV+K
Sbjct: 4   ALYAFEARNPDEISFQPGDIIQVDESQVAEPGWLAGELKGKTGWFPANYVEK 55



 Score = 32.7 bits (75), Expect = 0.021
 Identities = 17/39 (43%), Positives = 24/39 (61%), Gaps = 2/39 (5%)

Query: 224 LKLEIGDIIKVTKTNIN--GQWEGELNGKTGHFPFTHVE 260
           +  + GDII+V ++ +   G   GEL GKTG FP  +VE
Sbjct: 16  ISFQPGDIIQVDESQVAEPGWLAGELKGKTGWFPANYVE 54


>gnl|CDD|212820 cd11887, SH3_Bbc1, Src Homology 3 domain of Bbc1 and similar
           domains.  This subfamily is composed of Saccharomyces
           cerevisiae Bbc1p, also called Mti1p (Myosin tail
           region-interacting protein), and similar proteins. Bbc1p
           interacts with and regulates type I myosins in yeast,
           Myo3p and Myo5p, which are involved in actin
           cytoskeletal reorganization. It also binds and inhibits
           Las17, a WASp family protein that functions as an
           activator of the Arp2/3 complex. Bbc1p contains an
           N-terminal SH3 domain. SH3 domains bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs; they play a role in the
           regulation of enzymes by intramolecular interactions,
           changing the subcellular localization of signal pathway
           components and mediate multiprotein complex assemblies.
          Length = 60

 Score = 35.4 bits (82), Expect = 0.002
 Identities = 14/58 (24%), Positives = 28/58 (48%), Gaps = 4/58 (6%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI--SGEV--GSIPVPYVQK 165
           KV A Y ++ +  DDL F    ++ V  +++  W+  + +  +G    G  P  +V+ 
Sbjct: 3   KVKALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYVDSNGNTKEGIFPKNFVEV 60


>gnl|CDD|212991 cd12058, SH3_MLK4, Src Homology 3 domain of Mixed Lineage Kinase 4.
            MLK4 is a Serine/Threonine Kinase (STK), catalyzing the
           transfer of the gamma-phosphoryl group from ATP to S/T
           residues on protein substrates. MLKs act as
           mitogen-activated protein kinase kinase kinases (MAP3Ks,
           MKKKs, MAPKKKs), which phosphorylate and activate MAPK
           kinases (MAPKKs or MKKs or MAP2Ks), which in turn
           phosphorylate and activate MAPKs during signaling
           cascades that are important in mediating cellular
           responses to extracellular signals. MLKs play roles in
           immunity and inflammation, as well as in cell death,
           proliferation, and cell cycle regulation. The specific
           function of MLK4 is yet to be determined. Mutations in
           the kinase domain of MLK4 have been detected in
           colorectal cancers. MLK4 contains an SH3 domain, a
           catalytic kinase domain, a leucine zipper, a
           proline-rich region, and a CRIB domain that mediates
           binding to GTP-bound Cdc42 and Rac. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 58

 Score = 35.3 bits (81), Expect = 0.002
 Identities = 16/54 (29%), Positives = 30/54 (55%), Gaps = 6/54 (11%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKD-----EEHWWTAQNISGEVGSIPVPYV 163
           A YD++ +  D+L  ++ D++ V+S+D     ++ WW  + I   +G  P  YV
Sbjct: 4   ALYDYEASGEDELSLRRGDVVEVLSQDAAVSGDDGWWAGK-IRHRLGIFPANYV 56


>gnl|CDD|198252 cd10389, SH2_SHB, Src homology 2 domain found in SH2
          domain-containing adapter protein B (SHB).  SHB
          functions in generating signaling compounds in response
          to tyrosine kinase activation. SHB contains
          proline-rich motifs, a phosphotyrosine binding (PTB)
          domain, tyrosine phosphorylation sites, and a SH2
          domain. SHB mediates certain aspects of
          platelet-derived growth factor (PDGF) receptor-,
          fibroblast growth factor (FGF) receptor-, neural growth
          factor (NGF) receptor TRKA-, T cell receptor-,
          interleukin-2 (IL-2) receptor- and focal adhesion
          kinase- (FAK) signaling. SRC-like FYN-Related Kinase
          FRK/RAK (also named BSK/IYK or GTK) and SHB regulate
          apoptosis, proliferation and differentiation. SHB
          promotes apoptosis and is also required for proper
          mitogenicity, spreading and tubular morphogenesis in
          endothelial cells. SHB also plays a role in preventing
          early cavitation of embryoid bodies and reduces
          differentiation to cells expressing albumin, amylase,
          insulin and glucagon. SHB is a multifunctional protein
          that has difference responses in different cells under
          various conditions. In general SH2 domains are involved
          in signal transduction.  They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 97

 Score = 36.2 bits (83), Expect = 0.002
 Identities = 23/85 (27%), Positives = 42/85 (49%), Gaps = 4/85 (4%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
          WY G ++R +A+ +L   K+  ++LVR+S T   +Y L +K N    H    K+  T+++
Sbjct: 3  WYHGAISRGDAENLLRLCKE-CSYLVRNSQTSKHDYSLSLKSNQGFMHM---KLAKTKEK 58

Query: 73 TCYKIGDKTFSDLPSLLAFYKVHYL 97
                   F  +P ++ +Y    L
Sbjct: 59 YVLGQNSPPFDSVPEVIHYYTTRKL 83


>gnl|CDD|198209 cd10346, SH2_SH2B_family, Src homology 2 (SH2) domain found in
          SH2B adapter protein family.  The SH2B adapter protein
          family  has 3 members:  SH2B1 (SH2-B, PSM), SH2B2
          (APS), and SH2B3 (Lnk). SH2B family members contain a
          pleckstrin homology domain, at least one dimerization
          domain, and a C-terminal SH2 domain which binds to
          phosphorylated tyrosines in a variety of tyrosine
          kinases.  SH2B1 and SH2B2  function in signaling
          pathways found downstream of growth hormone receptor
          and receptor tyrosine kinases, including the insulin,
          insulin-like growth factor-I (IGF-I), platelet-derived
          growth factor (PDGF), nerve growth factor, hepatocyte
          growth factor, and fibroblast growth factor receptors.
          SH2B2beta, a new isoform of SH2B2, is an endogenous
          inhibitor of SH2B1 and/or SH2B2 (SH2B2alpha),
          negatively regulating insulin signaling and/or
          JAK2-mediated cellular responses. SH2B3 negatively
          regulates lymphopoiesis and early hematopoiesis. The
          lnk-deficiency results in enhanced production of B
          cells, and expansion as well as enhanced function of
          hematopoietic stem cells (HSCs), demonstrating negative
          regulatory functions of Sh2b3/Lnk in cytokine
          signaling. Sh2b3/Lnk also functions in responses
          controlled by cell adhesion and in crosstalk between
          integrin- and cytokine-mediated signaling. In general
          SH2 domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 97

 Score = 36.2 bits (84), Expect = 0.003
 Identities = 22/64 (34%), Positives = 33/64 (51%), Gaps = 5/64 (7%)

Query: 13 WYFGMMTRQEA-QAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTE 70
          W+ G ++R +A Q +L S  D +G FLVR S T  G +VL      +  H    ++T  E
Sbjct: 10 WFHGTLSRSDAAQLVLHSGADGHGVFLVRQSETRRGEFVLTFNFQGRAKHL---RLTLNE 66

Query: 71 QQTC 74
          +  C
Sbjct: 67 KGQC 70


>gnl|CDD|212759 cd11825, SH3_PLCgamma, Src homology 3 domain of Phospholipase C
           (PLC) gamma.  PLC catalyzes the hydrolysis of
           phosphatidylinositol (4,5)-bisphosphate [PtdIns(4,5)P2]
           to produce Ins(1,4,5)P3 and diacylglycerol (DAG) in
           response to various receptors. Ins(1,4,5)P3 initiates
           the calcium signaling cascade while DAG functions as an
           activator of PKC. PLCgamma catalyzes this reaction in
           tyrosine kinase-dependent signaling pathways. It is
           activated and recruited to its substrate at the
           membrane. Vertebrates contain two forms of PLCgamma,
           PLCgamma1, which is widely expressed, and PLCgamma2,
           which is primarily found in haematopoietic cells.
           PLCgamma contains a Pleckstrin homology (PH) domain
           followed by an elongation factor (EF) domain, two
           catalytic regions of PLC domains that flank two tandem
           SH2 domains, followed by a SH3 domain and C2 domain. The
           SH3 domain of PLCgamma1 directly interacts with
           dynamin-1 and can serve as a guanine nucleotide exchange
           factor (GEF). It also interacts with Cbl, inhibiting its
           phosphorylation and activity. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 35.0 bits (81), Expect = 0.003
 Identities = 17/53 (32%), Positives = 26/53 (49%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           V A YD+    PD+L F K+ I+  V K++  WW       +    P  YV++
Sbjct: 2   VKALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGKKQKWFPANYVEE 54


>gnl|CDD|212980 cd12047, SH3_Noxa1_C, C-terminal Src Homology 3 domain of NADPH
           oxidase activator 1.  Noxa1 is a homolog of p67phox and
           is a cytosolic subunit of the nonphagocytic NADPH
           oxidase complex Nox1, which catalyzes the transfer of
           electrons from NADPH to molecular oxygen to form
           superoxide. Noxa1 is co-expressed with Nox1 in colon,
           stomach, uterus, prostate, and vascular smooth muscle
           cells, consistent with its regulatory role. It does not
           interact with p40phox, unlike p67phox, making Nox1
           activity independent of p40phox, unlike Nox2. Noxa1
           contains TPR, PB1, and C-terminal SH3 domains, but lacks
           the central SH3 domain that is present in p67phox. The
           TPR domain binds activated GTP-bound Rac. The C-terminal
           SH3 domain binds the polyproline motif found at the
           C-terminus of Noxo1, a homolog of p47phox. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 34.8 bits (80), Expect = 0.003
 Identities = 12/54 (22%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +++A++D+    P+DL F + D + ++S+  + W    +  G +G  P  +  +
Sbjct: 1   RMVAQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEG-HCDGRIGIFPKCFAVR 53



 Score = 28.2 bits (63), Expect = 0.61
 Identities = 12/33 (36%), Positives = 19/33 (57%), Gaps = 2/33 (6%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFP 255
           L+   GD I +  + +N +W EG  +G+ G FP
Sbjct: 16  LEFSQGDTIDIL-SEVNQEWLEGHCDGRIGIFP 47


>gnl|CDD|212691 cd11757, SH3_SH3BP4, Src Homology 3 domain of SH3 domain-binding
           protein 4.  SH3 domain-binding protein 4 (SH3BP4) is
           also called transferrin receptor trafficking protein
           (TTP). SH3BP4 is an endocytic accessory protein that
           interacts with endocytic proteins including clathrin and
           dynamin, and regulates the internalization of the
           transferrin receptor (TfR). SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 52

 Score = 34.6 bits (79), Expect = 0.003
 Identities = 20/53 (37%), Positives = 27/53 (50%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +V+A  D+   +   L F K D L V+      WW A N + E+G IP  YVQ
Sbjct: 1   EVVAIKDYCPTNFTTLKFSKGDHLYVLDTSGGEWWYAHNTT-EMGYIPSSYVQ 52


>gnl|CDD|212818 cd11885, SH3_SH3TC, Src Homology 3 domain of SH3 domain and
           tetratricopeptide repeat-containing (SH3TC) proteins and
           similar domains.  This subfamily is composed of
           vertebrate SH3TC proteins and hypothetical fungal
           proteins containing BAR and SH3 domains. Mammals contain
           two SH3TC proteins, SH3TC1 and SH3TC2. The function of
           SH3TC1 is unknown. SH3TC2 is localized in Schwann cells
           in the peripheral nervous system, where it interacts
           with Rab11 and plays a role in peripheral nerve
           myelination. Mutations in SH3TC2 are associated with
           Charcot-Marie-Tooth disease type 4C, a severe hereditary
           peripheral neuropathy with symptoms that include
           progressive scoliosis, delayed age of walking, muscular
           atrophy, distal weakness, and reduced nerve conduction
           velocity. SH3 domains bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially to
           PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 55

 Score = 34.6 bits (80), Expect = 0.003
 Identities = 15/55 (27%), Positives = 28/55 (50%), Gaps = 3/55 (5%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEE--HWWTAQNI-SGEVGSIPVPYV 163
              AK DF+G +P +L F++ D + ++        W+  ++  SG VG +P  + 
Sbjct: 1   SCTAKMDFEGVEPGELSFRQGDSIEIIGDLIPGLQWFVGRSKSSGRVGFVPTNHF 55


>gnl|CDD|212969 cd12036, SH3_MPP5, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 5 (or MAGUK p55 subfamily member 5).
           MPP5, also called PALS1 (Protein associated with Lin7)
           or Nagie oko protein in zebrafish or Stardust in
           Drosophila, is a scaffolding protein which associates
           with Crumbs homolog 1 (CRB1), CRB2, or CRB3 through its
           PDZ domain and with PALS1-associated tight junction
           protein (PATJ) or multi-PDZ domain protein 1 (MUPP1)
           through its L27 domain. The resulting tri-protein
           complexes are core proteins of the Crumb complex, which
           localizes at tight junctions or subapical regions, and
           is involved in the maintenance of apical-basal polarity
           in epithelial cells and the morphogenesis and function
           of photoreceptor cells. MPP5 is critical for the proper
           stratification of the retina and is also expressed in T
           lymphocytes where it is important for TCR-mediated
           activation of NFkB. Drosophila Stardust exists in
           several isoforms, some of which show opposing functions
           in photoreceptor cells, which suggests that the relative
           ratio of different Crumbs complexes regulates
           photoreceptor homeostasis. MPP5 contains two L27 domains
           followed by the core of three domains characteristic of
           MAGUK (membrane-associated guanylate kinase) proteins:
           PDZ, SH3, and guanylate kinase (GuK). In addition, it
           also contains the Hook (Protein 4.1 Binding) motif in
           between the SH3 and GuK domains. The GuK domain in MAGUK
           proteins is enzymatically inactive; instead, the domain
           mediates protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 63

 Score = 35.1 bits (81), Expect = 0.004
 Identities = 17/46 (36%), Positives = 26/46 (56%), Gaps = 13/46 (28%)

Query: 113 VIAKYDFDGNDPDD----------LPFKKNDILIVVSKDEEHWWTA 148
           V A +D+D   P+D          L F+K DIL V+S+++ +WW A
Sbjct: 2   VRAHFDYD---PEDDPYIPCRELGLSFQKGDILHVISQEDPNWWQA 44


>gnl|CDD|212990 cd12057, SH3_CIN85_3, Third Src Homology 3 domain (SH3C) of
           Cbl-interacting protein of 85 kDa.  CIN85, also called
           SH3 domain-containing kinase-binding protein 1 (SH3KBP1)
           or CD2-binding protein 3 (CD2BP3) or Ruk, is an adaptor
           protein that is involved in the downregulation of
           receptor tyrosine kinases by facilitating endocytosis
           through interaction with endophilin-associated ubiquitin
           ligase Cbl proteins. It is also important in many other
           cellular processes including vesicle-mediated transport,
           cytoskeletal remodelling, apoptosis, cell adhesion and
           migration, and viral infection, among others. CIN85
           exists as multiple variants from alternative splicing;
           the main variant contains three SH3 domains, a
           proline-rich region, and a C-terminal coiled-coil
           domain. All of these domains enable CIN85 to bind
           various protein partners and assemble complexes that
           have been implicated in many different functions. This
           alignment model represents the third SH3 domain (SH3C)
           of CIN85. SH3C has been shown to bind ubiquitin. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 34.5 bits (79), Expect = 0.004
 Identities = 19/47 (40%), Positives = 30/47 (63%), Gaps = 2/47 (4%)

Query: 218 AYDKTALKLEIGDIIKV-TKTNIN-GQWEGELNGKTGHFPFTHVEFI 262
           A ++  L ++ GDI+ + +K  I+ G WEGELNG+ G FP   V+ +
Sbjct: 10  AQNEDELTIKEGDIVTLISKDCIDAGWWEGELNGRRGVFPDNFVKLL 56



 Score = 29.5 bits (66), Expect = 0.27
 Identities = 16/55 (29%), Positives = 32/55 (58%), Gaps = 5/55 (9%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKD--EEHWWTAQNISGEVGSIPVPYVQ 164
           KV+  + ++  + D+L  K+ DI+ ++SKD  +  WW  + ++G  G  P  +V+
Sbjct: 3   KVL--FPYEAQNEDELTIKEGDIVTLISKDCIDAGWWEGE-LNGRRGVFPDNFVK 54


>gnl|CDD|212866 cd11933, SH3_Nebulin_C, C-terminal Src Homology 3 domain of
           Nebulin.  Nebulin is a giant filamentous protein
           (600-900 kD) that is expressed abundantly in skeletal
           muscle. It binds to actin thin filaments and regulates
           its assembly and function. Nebulin was thought to be
           part of a molecular ruler complex that is critical in
           determining the lengths of actin thin filaments in
           skeletal muscle since its length, which varies due to
           alternative splicing, correlates with the length of thin
           filaments in various muscle types. Recent studies
           indicate that nebulin regulates thin filament length by
           stabilizing the filaments and preventing
           depolymerization. Mutations in nebulin can cause
           nemaline myopathy, characterized by muscle weakness
           which can be severe and can lead to neonatal lethality.
           Nebulin contains an N-terminal LIM domain, many nebulin
           repeats/super repeats, and a C-terminal SH3 domain. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 34.6 bits (79), Expect = 0.004
 Identities = 18/52 (34%), Positives = 28/52 (53%), Gaps = 3/52 (5%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWW--TAQNISGEVGSIPVPYVQ 164
           A YD+   D D++ FK  D ++ V   +E W   T Q  +G+ G +P  YV+
Sbjct: 6   AMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQR-TGKTGMLPANYVE 56


>gnl|CDD|212918 cd11985, SH3_Stac2_C, C-terminal Src homology 3 domain of SH3 and
           cysteine-rich domain-containing protein 2 (Stac2).  Stac
           proteins are putative adaptor proteins that contain a
           cysteine-rich C1 domain and one or two SH3 domains at
           the C-terminus. There are three mammalian members
           (Stac1, Stac2, and Stac3) of this family. Stac2 contains
           a single SH3 domain at the C-terminus unlike Stac1 and
           Stac3, which contain two C-terminal SH3 domains. Stac1
           and Stac2 have been found to be expressed differently in
           mature dorsal root ganglia (DRG) neurons. Stac1 is
           mainly expressed in peptidergic neurons while Stac2 is
           found in a subset of nonpeptidergic and all trkB+
           neurons. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 34.5 bits (79), Expect = 0.004
 Identities = 17/52 (32%), Positives = 26/52 (50%), Gaps = 1/52 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +A Y F   + +DLP +  D ++VV    E WW  +     VG  P  +VQ+
Sbjct: 3   VALYKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGK-SGDRVGFFPANFVQR 53



 Score = 27.2 bits (60), Expect = 1.6
 Identities = 11/41 (26%), Positives = 19/41 (46%)

Query: 220 DKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           +   L L+ GD + V   +    W+G+   + G FP   V+
Sbjct: 12  ENNDLPLQPGDRVMVVDDSNEDWWKGKSGDRVGFFPANFVQ 52


>gnl|CDD|198213 cd10350, SH2_SH2D4A, Src homology 2 domain found in the SH2
          domain containing protein 4A (SH2D4A).  SH2D4A contains
          a single SH2 domain. In general SH2 domains are
          involved in signal transduction.  They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 103

 Score = 35.7 bits (82), Expect = 0.005
 Identities = 18/52 (34%), Positives = 29/52 (55%), Gaps = 2/52 (3%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIIN 64
          W+ G++T ++A  +LLS    G+FL+R S  I G Y L         H++I+
Sbjct: 9  WFHGILTLKKANELLLSTM-PGSFLIRVSEKIKG-YALSYLSEEGCKHFLID 58


>gnl|CDD|213009 cd12076, SH3_Tks4_2, Second Src homology 3 domain of Tyrosine
           kinase substrate with four SH3 domains.  Tks4, also
           called SH3 and PX domain-containing protein 2B
           (SH3PXD2B) or HOFI, is a Src substrate and scaffolding
           protein that plays an important role in the formation of
           podosomes and invadopodia, the dynamic actin-rich
           structures that are related to cell migration and cancer
           cell invasion. It is required in the formation of
           functional podosomes, EGF-induced membrane ruffling, and
           lamellipodia generation. It plays an important role in
           cellular attachment and cell spreading. Tks4 is
           essential for the localization of MT1-MMP (membrane-type
           1 matrix metalloproteinase) to invadopodia. It contains
           an N-terminal Phox homology (PX) domain and four SH3
           domains. This model characterizes the second SH3 domain
           of Tks4. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 54

 Score = 34.2 bits (78), Expect = 0.005
 Identities = 16/55 (29%), Positives = 28/55 (50%), Gaps = 1/55 (1%)

Query: 111 EKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           EK    Y +   D D++  +K  ++ V+ K+ E WW  +   G+ G  P  Y++K
Sbjct: 1   EKYTVIYPYTARDQDEINLEKGAVVEVIQKNLEGWWKIR-YQGKEGWAPASYLKK 54


>gnl|CDD|212964 cd12031, SH3_DLG1, Src Homology 3 domain of Disks Large homolog 1. 
           DLG1, also called synapse-associated protein 97 (SAP97),
           is a scaffolding protein that clusters at synapses and
           plays an important role in synaptic development and
           plasticity. DLG1 plays roles in regulating cell
           polarity, proliferation, migration, and cycle
           progression. It interacts with AMPA-type glutamate
           receptors and is critical in their maturation and
           delivery to synapses. It also interacts with PKCalpha
           and promotes wound healing. DLG1 is a member of the
           MAGUK (membrane-associated guanylate kinase) protein
           family, which is characterized by the presence of a core
           of three domains: PDZ, SH3, and guanylate kinase (GuK).
           The GuK domain in MAGUK proteins is enzymatically
           inactive; instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. DLG1 contains three PDZ domains. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 67

 Score = 34.7 bits (79), Expect = 0.005
 Identities = 21/57 (36%), Positives = 29/57 (50%), Gaps = 10/57 (17%)

Query: 113 VIAKYDFDGNDPDDLP-----FKKNDILIVVSKDEEHWWTAQNI-----SGEVGSIP 159
           V A +D+D      LP     FK  DIL VV+  ++ WW A+ +     S E+G IP
Sbjct: 5   VRALFDYDKTKDSGLPSQGLNFKFGDILHVVNASDDEWWQARQVTADGESEEIGVIP 61


>gnl|CDD|212966 cd12033, SH3_MPP7, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 7 (or MAGUK p55 subfamily member 7).  MPP7
           is a scaffolding protein that binds to DLG1 and promotes
           tight junction formation and epithelial cell polarity.
           Mutations in the MPP7 gene may be associated with the
           pathogenesis of diabetes and extreme bone mineral
           density. It is one of seven vertebrate homologs of the
           Drosophila Stardust protein, which is required in
           establishing cell polarity, and it contains two L27
           domains followed by the core of three domains
           characteristic of MAGUK (membrane-associated guanylate
           kinase) proteins: PDZ, SH3, and guanylate kinase (GuK).
           The GuK domain in MAGUK proteins is enzymatically
           inactive; instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 61

 Score = 34.2 bits (78), Expect = 0.006
 Identities = 15/44 (34%), Positives = 26/44 (59%), Gaps = 7/44 (15%)

Query: 113 VIAKYDFDGNDPDDLP-------FKKNDILIVVSKDEEHWWTAQ 149
           + A +D++ N+   +P       FKK DIL ++S+D+  WW A+
Sbjct: 2   IKALFDYNPNEDKAIPCKEAGLSFKKGDILQIMSQDDATWWQAK 45


>gnl|CDD|212989 cd12056, SH3_CD2AP_3, Third Src Homology 3 domain (SH3C) of
           CD2-associated protein.  CD2AP, also called CMS (Cas
           ligand with Multiple SH3 domains) or METS1
           (Mesenchyme-to-Epithelium Transition protein with SH3
           domains), is a cytosolic adaptor protein that plays a
           role in regulating the cytoskeleton. It is critical in
           cell-to-cell union necessary for kidney function. It
           also stabilizes the contact between a T cell and
           antigen-presenting cells. It is primarily expressed in
           podocytes at the cytoplasmic face of the slit diaphragm
           and serves as a linker anchoring podocin and nephrin to
           the actin cytoskeleton. CD2AP contains three SH3
           domains, a proline-rich region, and a C-terminal
           coiled-coil domain. All of these domains enable CD2AP to
           bind various protein partners and assemble complexes
           that have been implicated in many different functions.
           This alignment model represents the third SH3 domain
           (SH3C) of CD2AP. SH3C has been shown to bind ubiquitin.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 34.0 bits (78), Expect = 0.006
 Identities = 15/34 (44%), Positives = 20/34 (58%), Gaps = 2/34 (5%)

Query: 224 LKLEIGDIIKVTKTNIN--GQWEGELNGKTGHFP 255
           L  + G+II +   +    G W+GELNGK G FP
Sbjct: 18  LDFKEGEIILIISKDTGEPGWWKGELNGKEGVFP 51



 Score = 32.5 bits (74), Expect = 0.027
 Identities = 16/47 (34%), Positives = 31/47 (65%), Gaps = 3/47 (6%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKD--EEHWWTAQNISGEVGSIP 159
           A + ++G + D+L FK+ +I++++SKD  E  WW  + ++G+ G  P
Sbjct: 6   ALFHYEGTNEDELDFKEGEIILIISKDTGEPGWWKGE-LNGKEGVFP 51


>gnl|CDD|212934 cd12001, SH3_BCAR1, Src homology 3 domain of the CAS
           (Crk-Associated Substrate) scaffolding protein family
           member, Breast Cancer Anti-estrogen Resistance 1.
           BCAR1, also called p130cas or CASS1, is the founding
           member of the CAS family of scaffolding proteins and was
           originally identified through its ability to associate
           with Crk. The name BCAR1 was designated because the
           human gene was identified in a screen for genes that
           promote resistance to tamoxifen. It is widely expressed
           and its deletion is lethal in mice. It plays a role in
           regulating cell motility, survival, proliferation,
           transformation, cancer progression, and bacterial
           pathogenesis. CAS proteins function as molecular
           scaffolds to regulate protein complexes that are
           involved in many cellular processes. They share a common
           domain structure that includes an N-terminal SH3 domain,
           an unstructured substrate domain that contains many YxxP
           motifs, a serine-rich four-helix bundle, and a FAT-like
           C-terminal domain. The SH3 domain of CAS proteins binds
           to diverse partners including FAK, FRNK, Pyk2, PTP-PEST,
           DOCK180, among others. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 68

 Score = 34.2 bits (78), Expect = 0.007
 Identities = 19/52 (36%), Positives = 29/52 (55%), Gaps = 6/52 (11%)

Query: 113 VIAK--YDFDGNDPDDLPFKKNDILIVVSKDEE---HWWTAQNISGEVGSIP 159
           V+AK  YD     PD+L F+K DI+ V+ +D +    WW   ++ G  G +P
Sbjct: 3   VLAKALYDNVAESPDELSFRKGDIMTVLERDTQGLDGWWLC-SLHGRQGIVP 53


>gnl|CDD|212836 cd11903, SH3_Nck2_3, Third Src Homology 3 domain of Nck2 adaptor
           protein.  Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4) plays a crucial role in
           connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds neuronal signaling
           proteins such as ephrinB and Disabled-1 (Dab-1)
           exclusively. Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2, which show partly overlapping functions but also
           bind distinct targets. The third SH3 domain of Nck
           appears to prefer ligands with a PxAPxR motif. SH3
           domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially a PxxP motif. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 59

 Score = 33.9 bits (77), Expect = 0.007
 Identities = 17/49 (34%), Positives = 26/49 (53%), Gaps = 2/49 (4%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEE--HWWTAQNISGEVGSIPVPYV 163
           Y F     ++L F+K + + V+ K E    WW  +N  G+VG +P  YV
Sbjct: 7   YPFSSVTEEELNFEKGETMEVIEKPENDPEWWKCKNSRGQVGLVPKNYV 55


>gnl|CDD|212865 cd11932, SH3_SH3RF2_2, Second Src Homology 3 domain of SH3 domain
           containing ring finger 2.  SH3RF2 is also called POSHER
           (POSH-eliminating RING protein) or HEPP1 (heart protein
           phosphatase 1-binding protein). It acts as an
           anti-apoptotic regulator of the JNK pathway by binding
           to and promoting the degradation of SH3RF1 (or POSH), a
           scaffold protein that is required for pro-apoptotic JNK
           activation. It may also play a role in cardiac functions
           together with protein phosphatase 1. SH3RF2 contains an
           N-terminal RING finger domain and three SH3 domains.
           This model represents the second SH3 domain, located
           C-terminal of the first SH3 domain at the N-terminal
           half, of SH3RF2. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 34.0 bits (78), Expect = 0.007
 Identities = 15/56 (26%), Positives = 31/56 (55%), Gaps = 5/56 (8%)

Query: 112 KVIAKYDFDGND----PDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           + +  +D    +     D L F+K+DI+ V+S+ +E+W   + +  +VG  P+ +V
Sbjct: 3   RALYNFDLKEKNREESKDCLKFQKDDIITVISRVDENWAEGK-LGDQVGIFPILFV 57


>gnl|CDD|212894 cd11961, SH3_Abp1_fungi_C2, Second C-terminal Src homology 3 domain
           of Fungal Actin-binding protein 1.  Abp1 is an adaptor
           protein that functions in receptor-mediated endocytosis
           and vesicle trafficking. It contains an N-terminal
           actin-binding module, the actin-depolymerizing factor
           (ADF) homology domain, a central proline-rich region,
           and a C-terminal SH3 domain (many yeast Abp1 proteins
           contain two C-terminal SH3 domains). Yeast Abp1 also
           contains two acidic domains that bind directly to the
           Arp2/3 complex, which is required to initiate actin
           polymerization. The SH3 domain of yeast Abp1 binds and
           localizes the kinases, Ark1p and Prk1p, which facilitate
           actin patch disassembly following vesicle
           internalization. It also mediates the localization to
           the actin patch of the synaptojanin-like protein, Sjl2p,
           which plays a key role in endocytosis. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 53

 Score = 33.7 bits (77), Expect = 0.007
 Identities = 16/52 (30%), Positives = 27/52 (51%), Gaps = 1/52 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
             A YD+D  + ++L F +ND +I +   ++ WW  +   G  G  P  YV+
Sbjct: 2   AKALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGE-CHGSRGLFPSNYVE 52



 Score = 28.6 bits (64), Expect = 0.46
 Identities = 9/18 (50%), Positives = 11/18 (61%)

Query: 243 WEGELNGKTGHFPFTHVE 260
           W GE +G  G FP  +VE
Sbjct: 35  WLGECHGSRGLFPSNYVE 52


>gnl|CDD|212778 cd11844, SH3_CAS, Src homology 3 domain of CAS (Crk-Associated
           Substrate) scaffolding proteins.  CAS proteins function
           as molecular scaffolds to regulate protein complexes
           that are involved in many cellular processes including
           migration, chemotaxis, apoptosis, differentiation, and
           progenitor cell function. They mediate the signaling of
           integrins at focal adhesions where they localize, and
           thus, regulate cell invasion and survival.
           Over-expression of these proteins is implicated in poor
           prognosis, increased metastasis, and resistance to
           chemotherapeutics in many cancers such as breast, lung,
           melanoma, and glioblastoma. CAS proteins have also been
           linked to the pathogenesis of inflammatory disorders,
           Alzheimer's, Parkinson's, and developmental defects.
           They share a common domain structure that includes an
           N-terminal SH3 domain, an unstructured substrate domain
           that contains many YxxP motifs, a serine-rich four-helix
           bundle, and a FAT-like C-terminal domain. Vertebrates
           contain four CAS proteins: BCAR1 (or p130Cas), NEDD9 (or
           HEF1), EFS (or SIN), and CASS4 (or HEPL). The SH3 domain
           of CAS proteins binds to diverse partners including FAK,
           FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 33.9 bits (78), Expect = 0.008
 Identities = 14/35 (40%), Positives = 20/35 (57%), Gaps = 3/35 (8%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDE---EHWW 146
           A YD     PD+L F++ DIL V+ ++    E WW
Sbjct: 4   ALYDNVAESPDELAFRRGDILTVLEQNTAGLEGWW 38


>gnl|CDD|212766 cd11832, SH3_Shank, Src homology 3 domain of SH3 and multiple
           ankyrin repeat domains (Shank) proteins.  Shank proteins
           carry scaffolding functions through multiple sites of
           protein-protein interaction in its domain architecture,
           including ankyrin (ANK) repeats, a long proline rich
           region, as well as SH3, PDZ, and SAM domains. They bind
           a variety of membrane and cytosolic proteins, and exist
           in alternatively spliced isoforms. They are highly
           enriched in postsynaptic density (PSD) where they
           interact with the cytoskeleton and with postsynaptic
           membrane receptors including NMDA and glutamate
           receptors. They are crucial in the construction and
           organization of the PSD and dendritic spines of
           excitatory synapses. There are three members of this
           family (Shank1, Shank2, Shank3) which show distinct and
           cell-type specific patterns of expression. Shank1 is
           brain-specific; Shank2 is found in neurons, glia,
           endocrine cells, liver, and kidney; Shank3 is widely
           expressed. The SH3 domain of Shank binds GRIP, a
           scaffold protein that binds AMPA receptors and Eph
           receptors/ligands. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 50

 Score = 33.6 bits (77), Expect = 0.008
 Identities = 14/32 (43%), Positives = 18/32 (56%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           + L  GD +KV      G WEG + G+TG FP
Sbjct: 16  ISLHKGDRVKVLSIGEGGFWEGSVRGRTGWFP 47


>gnl|CDD|212782 cd11848, SH3_SLAP-like, Src homology 3 domain of Src-Like Adaptor
           Proteins.  SLAPs are adaptor proteins with limited
           similarity to Src family tyrosine kinases. They contain
           an N-terminal SH3 domain followed by an SH2 domain, and
           a unique C-terminal sequence. They function in
           regulating the signaling, ubiquitination, and
           trafficking of T-cell receptor (TCR) and B-cell receptor
           (BCR) components. Vertebrates contain two SLAPs, named
           SLAP (or SLA1) and SLAP2 (or SLA2). SLAP has been shown
           to interact with the EphA receptor, EpoR, Lck, PDGFR,
           Syk, CD79a, among others, while SLAP2 interacts with
           CSF1R. Both SLAPs interact with c-Cbl, LAT, CD247, and
           Zap70. SLAP modulates TCR surface expression levels as
           well as surface and total BCR levels. As an adaptor to
           c-Cbl, SLAP increases the ubiquitination, intracellular
           retention, and targeted degradation of the BCR complex
           components. SLAP2 plays a role in c-Cbl-dependent
           regulation of CSF1R, a tyrosine kinase important for
           myeloid cell growth and differentiation. The SH3 domain
           of SLAP forms a complex with v-Abl. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 33.7 bits (77), Expect = 0.009
 Identities = 16/53 (30%), Positives = 25/53 (47%), Gaps = 2/53 (3%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTA-QNISGEVGSIPVPYVQK 165
           +A  D+    P +L  +  + L +VS DE  WW     ++G    IP  +V K
Sbjct: 3   VALGDYPSGGPAELSLRLGEPLTIVS-DEGDWWKVLSEVTGRESYIPSVHVAK 54


>gnl|CDD|212965 cd12032, SH3_DLG2, Src Homology 3 domain of Disks Large homolog 2. 
           DLG2, also called postsynaptic density-93 (PSD93) or
           Channel-associated protein of synapse-110 (chapsyn 110),
           is a scaffolding protein that clusters at synapses and
           plays an important role in synaptic development and
           plasticity. The DLG2 delta isoform binds inwardly
           rectifying potassium Kir2 channels, which determine
           resting membrane potential in neurons. It regulates the
           spatial and temporal distribution of Kir2 channels
           within neuronal membranes. DLG2 is a member of the MAGUK
           (membrane-associated guanylate kinase) protein family,
           which is characterized by the presence of a core of
           three domains: PDZ, SH3, and guanylate kinase (GuK). The
           GuK domain in MAGUK proteins is enzymatically inactive;
           instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. DLG2 contains three PDZ domains. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 74

 Score = 33.9 bits (77), Expect = 0.011
 Identities = 18/57 (31%), Positives = 30/57 (52%), Gaps = 10/57 (17%)

Query: 113 VIAKYDFDGNDPDDLP-----FKKNDILIVVSKDEEHWWTAQNI-----SGEVGSIP 159
           V A +D++ +    LP     F+  DIL V++  ++ WW A+ +     S E+G IP
Sbjct: 8   VRAMFDYEKSKDSGLPSQGLSFRYGDILHVINASDDEWWQARRVTPDGDSEEMGVIP 64


>gnl|CDD|198269 cd10406, SH2_Vav2, Src homology 2 (SH2) domain found in the Vav2
           proteins.  Proto-oncogene vav is a member of the Dbl
           family of guanine nucleotide exchange factors (GEF) for
           the Rho family of GTP binding proteins. All vavs are
           activated by tyrosine phosphorylation leading to their
           activation. There are three Vav mammalian family
           members: Vav1 which is expressed in the hematopoietic
           system, and Vav2 and Vav3 are more ubiquitously
           expressed. Vav2 is a GEF for RhoA, RhoB and RhoG and may
           activate Rac1 and Cdc42. Vav2 has been shown to interact
           with CD19 and Grb2. Alternatively spliced transcript
           variants encoding different isoforms have been found for
           Vav2. Vav proteins are involved in several processes
           that require cytoskeletal reorganization, such as the
           formation of the immunological synapse (IS),
           phagocytosis, platelet aggregation, spreading, and
           transformation. Vavs function as guanine nucleotide
           exchange factors (GEFs) for the Rho/Rac family of
           GTPases. Vav family members have several conserved
           motifs/domains including: a leucine-rich region, a
           leucine-zipper, a calponin homology (CH) domain, an
           acidic domain, a Dbl-homology (DH) domain, a pleckstrin
           homology (PH) domain, a cysteine-rich domain, 2 SH3
           domains, a proline-rich region, and a SH2 domain.  Vavs
           are the only known Rho GEFs that have both the DH/PH
           motifs and SH2/SH3 domains in the same protein. The
           leucine-rich helix-loop-helix (HLH) domain is thought to
           be involved in protein heterodimerization with other HLH
           proteins and it may function as a negative regulator by
           forming inactive heterodimers. The CH domain  is usually
           involved in the association with filamentous actin, but
           in Vav it controls NFAT stimulation, Ca2+ mobilization,
           and its transforming activity. Acidic domains are
           involved in protein-protein interactions and contain
           regulatory tyrosines. The DH domain is a GDP-GTP
           exchange factor on Rho/Rac GTPases. The PH domain in
           involved in interactions with GTP-binding proteins,
           lipids and/or phosphorylated serine/threonine residues.
           The SH3 domain is involved in localization of proteins
           to specific sites within the cell interacting with
           protein with proline-rich sequences. The SH2 domain
           mediates a high affinity interaction with tyrosine
           phosphorylated proteins. In general SH2 domains are
           involved in signal transduction. They typically bind
           pTyr-containing ligands via two surface pockets, a pTyr
           and hydrophobic binding pocket, allowing proteins with
           SH2 domains to localize to tyrosine phosphorylated
           sites.
          Length = 103

 Score = 34.7 bits (79), Expect = 0.012
 Identities = 25/89 (28%), Positives = 42/89 (47%), Gaps = 7/89 (7%)

Query: 13  WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
           W+ G M RQ+   +L S   +G +L+R+       + + +K N++V H     I   E+ 
Sbjct: 7   WFAGNMERQQTDNLLKSHA-SGTYLIRERPAEAERFAISIKFNDEVKH-----IKVVEKD 60

Query: 73  TCYKIGD-KTFSDLPSLLAFYKVHYLDTS 100
               I + K F  L  L+ +Y+ H L  S
Sbjct: 61  NWIHITEAKKFESLLELVEYYQCHSLKES 89


>gnl|CDD|212781 cd11847, SH3_Brk, Src homology 3 domain of Brk (Breast tumor
           kinase) Protein Tyrosine Kinase (PTK), also called PTK6.
            Brk is a cytoplasmic (or non-receptor) PTK with limited
           homology to Src kinases. It has been found to be
           overexpressed in a majority of breast tumors. It plays
           roles in normal cell differentiation, proliferation,
           survival, migration, and cell cycle progression. Brk
           substrates include RNA-binding proteins (SLM-1/2,
           Sam68), transcription factors (STAT3/5), and signaling
           molecules (Akt, paxillin, IRS-4). Src kinases in general
           contain an N-terminal SH4 domain with a myristoylation
           site, followed by SH3 and SH2 domains, a tyr kinase
           domain, and a regulatory C-terminal region containing a
           conserved tyr; they are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). However, Brk lacks the
           N-terminal myristoylation site. The SH3 domain of Src
           kinases contributes to substrate recruitment by binding
           adaptor proteins/substrates, and regulation of kinase
           activity through an intramolecular interaction. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 33.3 bits (76), Expect = 0.012
 Identities = 14/54 (25%), Positives = 22/54 (40%), Gaps = 4/54 (7%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNIS---GEVGSIPVPY 162
              A +DF     ++L F+  D   +  +  + WWTA  +    G V    VP 
Sbjct: 1   IYKALWDFKARGDEELSFQAGDQFRIAERSGD-WWTALKLDRAGGVVAQGFVPN 53


>gnl|CDD|212904 cd11971, SH3_Abi1, Src homology 3 domain of Abl Interactor 1.
           Abi1, also called e3B1, is a central regulator of actin
           cytoskeletal reorganization through interactions with
           many protein complexes. It is part of WAVE, a
           nucleation-promoting factor complex, that links Rac 1
           activation to actin polymerization causing lamellipodia
           protrusion at the plasma membrane. Abi1 interact with
           formins to promote protrusions at the leading edge of
           motile cells. It also is a target of alpha4 integrin,
           regulating membrane protrusions at sites of integrin
           engagement. Abi proteins are adaptor proteins serving as
           binding partners and substrates of Abl tyrosine kinases.
           They are involved in regulating actin cytoskeletal
           reorganization and play important roles in
           membrane-ruffling, endocytosis, cell motility, and cell
           migration. Abi proteins contain a homeobox homology
           domain, a proline-rich region, and a SH3 domain. The SH3
           domain of Abi binds to a PxxP motif in Abl. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 59

 Score = 33.5 bits (76), Expect = 0.012
 Identities = 18/34 (52%), Positives = 21/34 (61%)

Query: 229 GDIIKVTKTNINGQWEGELNGKTGHFPFTHVEFI 262
           G II V K N +G +EG  NG TG FP  +VE I
Sbjct: 21  GAIIYVIKKNDDGWYEGVCNGVTGLFPGNYVESI 54



 Score = 33.5 bits (76), Expect = 0.012
 Identities = 17/53 (32%), Positives = 30/53 (56%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           KV+A YD+  +  D+L F +  I+ V+ K+++ W+     +G  G  P  YV+
Sbjct: 1   KVVAIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVC-NGVTGLFPGNYVE 52


>gnl|CDD|198246 cd10383, SH2_SOCS2, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7).  In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 103

 Score = 34.5 bits (79), Expect = 0.012
 Identities = 15/33 (45%), Positives = 20/33 (60%), Gaps = 1/33 (3%)

Query: 10 RNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSN 42
          +  WY+G MT  EA+   L +   G FLVRDS+
Sbjct: 6  QTGWYWGSMTVNEAKEK-LQDAPEGTFLVRDSS 37


>gnl|CDD|212734 cd11800, SH3_DNMBP_C2_like, Second C-terminal Src homology 3 domain
           of Dynamin Binding Protein, also called Tuba, and
           similar domains.  DNMBP or Tuba is a cdc42-specific
           guanine nucleotide exchange factor (GEF) that contains
           four N-terminal SH3 domains, a central RhoGEF [or Dbl
           homology (DH)] domain followed by a Bin/Amphiphysin/Rvs
           (BAR) domain, and two C-terminal SH3 domains. It
           provides a functional link between dynamin, Rho GTPase
           signaling, and actin dynamics. It plays an important
           role in regulating cell junction configuration. The
           C-terminal SH3 domains of DNMBP bind to N-WASP and
           Ena/VASP proteins, which are key regulatory proteins of
           the actin cytoskeleton. Also included in this subfamily
           is the second C-terminal SH3 domain of Rho guanine
           nucleotide exchange factor 37 (ARHGEF37), whose function
           is still unknown. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 33.1 bits (76), Expect = 0.013
 Identities = 14/57 (24%), Positives = 26/57 (45%), Gaps = 5/57 (8%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEH----WWTAQNISGEVGSIPVPYVQK 165
             A Y F+   P +L   +  ++ V+ K +      WW  ++  G+ G +P  Y+ K
Sbjct: 2   YYALYTFEARSPGELSVTEGQVVTVLEKHDLKGNPEWWLVED-RGKQGYVPSNYLAK 57


>gnl|CDD|212947 cd12014, SH3_RIM-BP_1, First Src homology 3 domain of
           Rab3-interacting molecules (RIMs) binding proteins.
           RIMs binding proteins (RBPs, RIM-BPs) associate with
           calcium channels present in photoreceptors, neurons, and
           hair cells; they interact simultaneously with specific
           calcium channel subunits, and active zone proteins, RIM1
           and RIM2. RIMs are part of the matrix at the presynaptic
           active zone and are associated with synaptic vesicles
           through their interaction with the small GTPase Rab3.
           RIM-BPs play a role in regulating synaptic transmission
           by serving as adaptors and linking calcium channels with
           the synaptic vesicle release machinery. RIM-BPs contain
           three SH3 domains and two to three fibronectin III
           repeats. Invertebrates contain one, while vertebrates
           contain at least two RIM-BPs, RIM-BP1 and RIM-BP2.
           RIM-BP1 is also called peripheral-type benzodiazapine
           receptor associated protein 1 (PRAX-1). Mammals contain
           a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are
           predominantly expressed in the brain where they display
           overlapping but distinct expression patterns, while
           RIM-BP3 is almost exclusively expressed in the testis
           and is essential in spermiogenesis. The SH3 domains of
           RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and
           L-type (alpha1D) and N-type (alpha1B) calcium channel
           subunits. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity. They play versatile and diverse roles
           in the cell including the regulation of enzymes,
           changing the subcellular localization of signaling
           pathway components, and mediating the formation of
           multiprotein complex assemblies.
          Length = 62

 Score = 33.5 bits (77), Expect = 0.013
 Identities = 13/61 (21%), Positives = 30/61 (49%), Gaps = 8/61 (13%)

Query: 113 VIAKYDFD------GNDPD-DLPFKKNDILIVVSK-DEEHWWTAQNISGEVGSIPVPYVQ 164
            +A+Y ++        +P+ +LP    D + V    DE+ ++  + + G  G +P  +V+
Sbjct: 2   FVARYSYNPLRDSPNENPEAELPLNAGDYVYVYGDMDEDGFYEGELLDGRRGLVPSNFVE 61

Query: 165 K 165
           +
Sbjct: 62  R 62


>gnl|CDD|212919 cd11986, SH3_Stac3_1, First C-terminal Src homology 3 domain of SH3
           and cysteine-rich domain-containing protein 3 (Stac3).
           Stac proteins are putative adaptor proteins that contain
           a cysteine-rich C1 domain and one or two SH3 domains at
           the C-terminus. There are three mammalian members
           (Stac1, Stac2, and Stac3) of this family. Stac1 and
           Stac3 contain two SH3 domains while Stac2 contains a
           single SH3 domain at the C-terminus. Stac1 and Stac2
           have been found to be expressed differently in mature
           dorsal root ganglia (DRG) neurons. Stac1 is mainly
           expressed in peptidergic neurons while Stac2 is found in
           a subset of nonpeptidergic and all trkB+ neurons. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 33.0 bits (75), Expect = 0.013
 Identities = 14/50 (28%), Positives = 24/50 (48%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +A Y F   + DDL F   + + V+    E WW  + I  + G  P+ ++
Sbjct: 3   VALYRFKALEKDDLDFHPGERITVIDDSNEEWWRGK-IGEKTGYFPMNFI 51



 Score = 27.2 bits (60), Expect = 1.5
 Identities = 13/42 (30%), Positives = 20/42 (47%)

Query: 218 AYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           A +K  L    G+ I V   +    W G++  KTG+FP   +
Sbjct: 10  ALEKDDLDFHPGERITVIDDSNEEWWRGKIGEKTGYFPMNFI 51


>gnl|CDD|212845 cd11912, SH3_Bzz1_1, First Src Homology 3 domain of Bzz1 and
           similar domains.  Bzz1 (or Bzz1p) is a
           WASP/Las17-interacting protein involved in endocytosis
           and trafficking to the vacuole. It physically interacts
           with type I myosins and functions in the early steps of
           endocytosis. Together with other proteins, it induces
           membrane scission in yeast. Bzz1 contains an N-terminal
           F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a
           central coiled-coil, and two C-terminal SH3 domains.
           This model represents the first C-terminal SH3 domain.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 33.0 bits (76), Expect = 0.014
 Identities = 14/49 (28%), Positives = 27/49 (55%), Gaps = 1/49 (2%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEHWWT-AQNISGEVGSIPVPYVQ 164
           YD+  +  D++   + + + V+  D+   WT  +N SGE G +P  Y++
Sbjct: 6   YDYTASGDDEVSISEGEEVTVLEPDDGSGWTKVRNGSGEEGLVPTSYIE 54


>gnl|CDD|198279 cd10416, SH2_SH2D2A, Src homology 2 domain found in the SH2 domain
           containing protein 2A (SH2D2A).  SH2D2A contains a
           single SH2 domain. In general SH2 domains are involved
           in signal transduction.  They typically bind
           pTyr-containing ligands via two surface pockets, a pTyr
           and hydrophobic binding pocket, allowing proteins with
           SH2 domains to localize to tyrosine phosphorylated
           sites.
          Length = 102

 Score = 34.2 bits (78), Expect = 0.014
 Identities = 27/98 (27%), Positives = 45/98 (45%), Gaps = 10/98 (10%)

Query: 13  WYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQ 72
           W+ G +TR+EA+  LL  K  G +LVR S + +  +VL  +      H+++ ++ +    
Sbjct: 9   WFHGFITRREAER-LLEPKPQGCYLVRFSESAV-TFVLTYRSRTCCRHFLLAQLRDGRHV 66

Query: 73  TCYKIGDKTFSDLPSLLAFYKVHYLD------TSPLIK 104
              +  D   + L  LL  Y  H L       T PL +
Sbjct: 67  VLGE--DSAHARLQDLLLHYTAHPLSPYGETLTEPLAR 102


>gnl|CDD|212724 cd11790, SH3_Amphiphysin, Src Homology 3 domain of Amphiphysin and
           related domains.  Amphiphysins function primarily in
           endocytosis and other membrane remodeling events. They
           exist in several isoforms and mammals possess two
           amphiphysin proteins from distinct genes. Amphiphysin I
           proteins, enriched in the brain and nervous system,
           contain domains that bind clathrin, Adaptor Protein
           complex 2 (AP2), dynamin, and synaptojanin. They
           function in synaptic vesicle endocytosis. Human
           autoantibodies to amphiphysin I hinder GABAergic
           signaling and contribute to the pathogenesis of
           paraneoplastic stiff-person syndrome. Some amphiphysin
           II isoforms, also called Bridging integrator 1 (Bin1),
           are localized in many different tissues and may function
           in intracellular vesicle trafficking. In skeletal
           muscle, Bin1 plays a role in the organization and
           maintenance of the T-tubule network. Mutations in Bin1
           are associated with autosomal recessive centronuclear
           myopathy. Amphiphysins contain an N-terminal BAR domain
           with an additional N-terminal amphipathic helix (an
           N-BAR), a variable central domain, and a C-terminal SH3
           domain. The SH3 domain of amphiphysins bind proline-rich
           motifs present in binding partners such as dynamin,
           synaptojanin, and nsP3. It also belongs to a subset of
           SH3 domains that bind ubiquitin in a site that overlaps
           with the peptide binding site. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 64

 Score = 33.1 bits (76), Expect = 0.014
 Identities = 12/32 (37%), Positives = 21/32 (65%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEE 143
           KV A +D+   D D+L F+K D+++V+  D+ 
Sbjct: 4   KVRATHDYTAEDTDELTFEKGDVILVIPFDDP 35


>gnl|CDD|212855 cd11922, SH3_Sorbs1_2, Second Src Homology 3 domain of Sorbin and
           SH3 domain containing 1 (Sorbs1), also called ponsin.
           Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl
           associated protein). It is an adaptor protein containing
           one sorbin homology (SoHo) and three SH3 domains. It
           binds Cbl and plays a major role in regulating the
           insulin signaling pathway by enhancing insulin-induced
           phosphorylation of Cbl. Sorbs1, like vinexin, localizes
           at cell-ECM and cell-cell adhesion sites where it binds
           vinculin, paxillin, and afadin. It may function in the
           control of cell motility. Other interaction partners of
           Sorbs1 include c-Abl, Sos, flotillin, Grb4, ataxin-7,
           filamin C, among others. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 58

 Score = 33.0 bits (75), Expect = 0.014
 Identities = 15/53 (28%), Positives = 32/53 (60%), Gaps = 3/53 (5%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISG--EVGSIPVPYVQ 164
           IAK++F+G+   ++ F+K + + ++ + +E+W+  + I G    G  P+ YV 
Sbjct: 4   IAKFNFNGDTQVEMSFRKGERITLLRQVDENWYEGR-IPGTSRQGIFPITYVD 55


>gnl|CDD|212712 cd11778, SH3_Bzz1_2, Second Src Homology 3 domain of Bzz1 and
           similar domains.  Bzz1 (or Bzz1p) is a
           WASP/Las17-interacting protein involved in endocytosis
           and trafficking to the vacuole. It physically interacts
           with type I myosins and functions in the early steps of
           endocytosis. Together with other proteins, it induces
           membrane scission in yeast. Bzz1 contains an N-terminal
           F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a
           central coiled-coil, and two C-terminal SH3 domains.
           This model represents the second C-terminal SH3 domain.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 51

 Score = 32.9 bits (75), Expect = 0.014
 Identities = 15/51 (29%), Positives = 24/51 (47%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPY 162
            V A YD++    D++  +  D + V+  D+   WT   I+G  G  P  Y
Sbjct: 1   YVEALYDYEAQGDDEISIRVGDRIAVIRGDDGSGWTYGEINGVKGLFPTSY 51



 Score = 30.5 bits (69), Expect = 0.095
 Identities = 12/33 (36%), Positives = 18/33 (54%), Gaps = 1/33 (3%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFP 255
           + + +GD I V + +    W  GE+NG  G FP
Sbjct: 16  ISIRVGDRIAVIRGDDGSGWTYGEINGVKGLFP 48


>gnl|CDD|212799 cd11865, SH3_Nbp2-like, Src Homology 3 domain of Saccharomyces
           cerevisiae Nap1-binding protein 2 and similar fungal
           proteins.  This subfamily includes Saccharomyces
           cerevisiae Nbp2 (Nucleosome assembly protein 1
           (Nap1)-binding protein 2), Schizosaccharomyces pombe
           Skb5, and similar proteins. Nbp2 interacts with Nap1,
           which is essential for maintaining proper nucleosome
           structures in transcription and replication. It is also
           the binding partner of the yeast type II protein
           phosphatase Ptc1p and serves as a scaffolding protein
           that brings seven kinases in close contact to Ptc1p.
           Nbp2 plays a role many cell processes including
           organelle inheritance, mating hormone response, cell
           wall stress, mitotic cell growth at elevated
           temperatures, and high osmolarity. Skb5 interacts with
           the p21-activated kinase (PAK) homolog Shk1, which is
           critical for fission yeast cell viability. Skb5
           activates Shk1 and plays a role in regulating cell
           morphology and growth under hypertonic conditions. Nbp2
           and Skb5 contain an SH3 domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 32.9 bits (75), Expect = 0.015
 Identities = 15/54 (27%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQN-ISGEVGSIPVPYVQ 164
           + +A YDF+    ++L F +  IL ++ K  + W  A++   G+ G +P  +V 
Sbjct: 1   RAVALYDFEPEHDNELGFAEGQILFILYKHGQGWLIAEDESGGKTGLVPEEFVS 54


>gnl|CDD|212868 cd11935, SH3_Nebulette_C, C-terminal Src Homology 3 domain of
           Nebulette and LIM-nebulette (or Lasp2).  Nebulette is a
           cardiac-specific protein that localizes to the Z-disc.
           It interacts with tropomyosin and is important in
           stabilizing actin thin filaments in cardiac muscles.
           Polymorphisms in the nebulette gene are associated with
           dilated cardiomyopathy, with some mutations resulting in
           severe heart failure. Nebulette is a 107kD protein that
           contains an N-terminal acidic region, multiple nebulin
           repeats, and a C-terminal SH3 domain. LIM-nebulette,
           also called Lasp2 (LIM and SH3 domain protein 2), is an
           alternatively spliced variant of nebulette. Although it
           shares a gene with nebulette, Lasp2 is not transcribed
           from a muscle-specific promoter, giving rise to its
           multiple tissue expression pattern with highest amounts
           in the brain. It can crosslink actin filaments and it
           affects cell spreading. Lasp2 is a 34kD protein
           containing an N-terminal LIM domain, three nebulin
           repeats, and a C-terminal SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 58

 Score = 33.1 bits (75), Expect = 0.015
 Identities = 16/52 (30%), Positives = 27/52 (51%), Gaps = 3/52 (5%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWW--TAQNISGEVGSIPVPYVQ 164
           A YD+   D D++ F+  D ++ V   +E W   T Q  +G  G +P  Y++
Sbjct: 5   AMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVQR-TGRTGMLPANYIE 55


>gnl|CDD|212730 cd11796, SH3_DNMBP_N3, Third N-terminal Src homology 3 domain of
           Dynamin Binding Protein, also called Tuba.  DNMBP or
           Tuba is a cdc42-specific guanine nucleotide exchange
           factor (GEF) that contains four N-terminal SH3 domains,
           a central RhoGEF [or Dbl homology (DH)] domain followed
           by a Bin/Amphiphysin/Rvs (BAR) domain, and two
           C-terminal SH3 domains. It provides a functional link
           between dynamin and key regulatory proteins of the actin
           cytoskeleton. It plays an important role in regulating
           cell junction configuration. The four N-terminal SH3
           domains of DNMBP binds the GTPase dynamin, which plays
           an important role in the fission of endocytic vesicles.
           SH3 domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 51

 Score = 32.7 bits (75), Expect = 0.018
 Identities = 14/32 (43%), Positives = 19/32 (59%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           L L  GD++ +T     G + GELNG+ G FP
Sbjct: 16  LDLREGDVVTITGILDKGWFRGELNGRRGIFP 47


>gnl|CDD|212864 cd11931, SH3_SH3RF3_2, Second Src Homology 3 domain of SH3 domain
           containing ring finger 3, an E3 ubiquitin-protein
           ligase.  SH3RF3 is also called POSH2 (Plenty of SH3s 2)
           or SH3MD4 (SH3 multiple domains protein 4). It is a
           scaffold protein with E3 ubiquitin-protein ligase
           activity. It was identified in the screen for
           interacting partners of p21-activated kinase 2 (PAK2).
           It may play a role in regulating JNK mediated apoptosis
           in certain conditions. It also interacts with GTP-loaded
           Rac1. SH3RF3 is highly homologous to SH3RF1; it also
           contains an N-terminal RING finger domain and four SH3
           domains. This model represents the second SH3 domain,
           located C-terminal of the first SH3 domain at the
           N-terminal half, of SH3RF3. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 32.6 bits (74), Expect = 0.018
 Identities = 20/54 (37%), Positives = 32/54 (59%), Gaps = 7/54 (12%)

Query: 115 AKYDFDGNDPDD----LPFKKNDILIVVSKDEEHWWTAQNISGE-VGSIPVPYV 163
           A YDF+  D D     L F K++IL V+ + +E+W  A+ + G+ +G  P+ YV
Sbjct: 4   ALYDFEIKDKDQDKDCLTFTKDEILTVIRRVDENW--AEGMLGDKIGIFPILYV 55


>gnl|CDD|212829 cd11896, SH3_SNX33, Src Homology 3 domain of Sorting Nexin 33.
           SNX33 interacts with Wiskott-Aldrich syndrome protein
           (WASP) and plays a role in the maintenance of cell shape
           and cell cycle progression. It modulates the shedding
           and endocytosis of cellular prion protein (PrP(c)) and
           amyloid precursor protein (APP). SNXs are Phox homology
           (PX) domain containing proteins that are involved in
           regulating membrane traffic and protein sorting in the
           endosomal system. SNX33 also contains BAR and SH3
           domains. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 32.6 bits (74), Expect = 0.019
 Identities = 16/54 (29%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDE-EHWWTAQNISGEVGSIPVPYVQ 164
           K  A Y F   + +++  ++N+ L++ S++  + W   QN  GE G  P  YV+
Sbjct: 1   KARALYSFQSENKEEINIQENEELVIFSENSLDGWLQGQNSRGETGLFPASYVE 54


>gnl|CDD|198208 cd10345, SH2_C-SH2_Zap70_Syk_like, C-terminal Src homology 2
          (SH2) domain found in Zeta-chain-associated protein
          kinase 70 (ZAP-70) and Spleen tyrosine kinase (Syk)
          proteins.  ZAP-70 and Syk comprise a family of
          hematopoietic cell specific protein tyrosine kinases
          (PTKs) that are required for antigen and antibody
          receptor function. ZAP-70 is expressed in T and natural
          killer (NK) cells and Syk is expressed in B cells, mast
          cells, polymorphonuclear leukocytes, platelets,
          macrophages, and immature T cells. They are required
          for the proper development of T and B cells, immune
          receptors, and activating NK cells. They consist of two
          N-terminal Src homology 2 (SH2) domains and a
          C-terminal kinase domain separated from the SH2 domains
          by a linker or hinge region. Phosphorylation of both
          tyrosine residues within the Immunoreceptor
          Tyrosine-based Activation Motifs (ITAM; consensus
          sequence Yxx[LI]x(7,8)Yxx[LI]) by the Src-family PTKs
          is required for efficient interaction of ZAP-70 and Syk
          with the receptor subunits and for receptor function.
          ZAP-70 forms two phosphotyrosine binding pockets, one
          of which is shared by both SH2 domains. In Syk the two
          SH2 domains do not form such a phosphotyrosine-binding
          site. The SH2 domains here are believed to function
          independently. In addition, the two SH2 domains of Syk
          display flexibility in their relative orientation,
          allowing Syk to accommodate a greater variety of
          spacing sequences between the ITAM phosphotyrosines and
          singly phosphorylated non-classical ITAM ligands. This
          model contains the C-terminus SH2 domains of both Syk
          and Zap70. In general SH2 domains are involved in
          signal transduction.  They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 95

 Score = 33.9 bits (77), Expect = 0.019
 Identities = 28/83 (33%), Positives = 43/83 (51%), Gaps = 5/83 (6%)

Query: 13 WYFGMMTRQEAQAILLS-EKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQ 71
          W+ G ++R+E++ I+L   K NG FL+R  +   G+Y LC+    KV HY I+K  +   
Sbjct: 2  WFHGKISREESEQIVLIGSKTNGKFLIRARDN-NGSYALCLLHEGKVLHYRIDK--DKTG 58

Query: 72 QTCYKIGDKTFSDLPSLLAFYKV 94
          +     G K F  L  L+  Y  
Sbjct: 59 KLSIPEGKK-FDTLWQLVEHYSY 80


>gnl|CDD|212951 cd12018, SH3_Tks4_4, Fourth (C-terminal) Src homology 3 domain of
           Tyrosine kinase substrate with four SH3 domains.  Tks4,
           also called SH3 and PX domain-containing protein 2B
           (SH3PXD2B) or HOFI, is a Src substrate and scaffolding
           protein that plays an important role in the formation of
           podosomes and invadopodia, the dynamic actin-rich
           structures that are related to cell migration and cancer
           cell invasion. It is required in the formation of
           functional podosomes, EGF-induced membrane ruffling, and
           lamellipodia generation. It plays an important role in
           cellular attachment and cell spreading. Tks4 is
           essential for the localization of MT1-MMP (membrane-type
           1 matrix metalloproteinase) to invadopodia. It contains
           an N-terminal Phox homology (PX) domain and four SH3
           domains. This model characterizes the fourth
           (C-terminal) SH3 domain of Tks4. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 56

 Score = 32.6 bits (74), Expect = 0.019
 Identities = 19/55 (34%), Positives = 28/55 (50%), Gaps = 4/55 (7%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEV---GSIPVPYVQK 165
           +A  DF+G D D   FK+  +  V  K+   WW  + +SG     G IP  Y++K
Sbjct: 3   VAVADFEG-DEDTSSFKEGTVFEVREKNSSGWWFCKVLSGGPVWEGWIPSNYLRK 56


>gnl|CDD|212867 cd11934, SH3_Lasp1_C, C-terminal Src Homology 3 domain of LIM and
           SH3 domain protein 1.  Lasp1 is a cytoplasmic protein
           that binds focal adhesion proteins and is involved in
           cell signaling, migration, and proliferation. It is
           overexpressed in several cancer cells including breast,
           ovarian, bladder, and liver. In cancer cells, it can be
           found in the nucleus; its degree of nuclear localization
           correlates with tumor size and poor prognosis. Lasp1 is
           a 36kD protein containing an N-terminal LIM domain, two
           nebulin repeats, and a C-terminal SH3 domain. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 59

 Score = 32.7 bits (74), Expect = 0.020
 Identities = 14/51 (27%), Positives = 29/51 (56%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHW-WTAQNISGEVGSIPVPYVQ 164
           A YD++  D D++ F+  D ++ V + ++ W +     +G+ G +P  YV+
Sbjct: 7   AVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGTVERTGDTGMLPANYVE 57


>gnl|CDD|212898 cd11965, SH3_ASAP1, Src homology 3 domain of ArfGAP with SH3
           domain, ankyrin repeat and PH domain containing protein
           1.  ASAP1 is also called DDEF1 (Development and
           Differentiation Enhancing Factor 1), AMAP1, centaurin
           beta-4, or PAG2. an Arf GTPase activating protein (GAP)
           with activity towards Arf1 and Arf5 but not Arf6.
           However, it has been shown to bind GTP-Arf6 stably
           without GAP activity. It has been implicated in cell
           growth, migration, and survival, as well as in tumor
           invasion and malignancy. It binds paxillin and
           cortactin, two components of invadopodia which are
           essential for tumor invasiveness. It also binds focal
           adhesion kinase (FAK) and the SH2/SH3 adaptor CrkL.
           ASAP1 contains an N-terminal BAR domain, followed by a
           Pleckstrin homology (PH) domain, an Arf GAP domain,
           ankyrin (ANK) repeats, and a C-terminal SH3 domain. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 57

 Score = 32.7 bits (74), Expect = 0.020
 Identities = 16/56 (28%), Positives = 31/56 (55%), Gaps = 4/56 (7%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGE---VGSIPVPYVQ 164
           +V   YD   ++ D+L F + +++IV  ++++ WW   +I G+    G  PV +V 
Sbjct: 1   RVKTIYDCQADNDDELTFVEGEVIIVTGEEDQEWWIG-HIEGQPERKGVFPVSFVH 55


>gnl|CDD|212933 cd12000, SH3_CASS4, Src homology 3 domain of CAS (Crk-Associated
           Substrate) scaffolding protein family member 4.  CASS4,
           also called HEPL (HEF1-EFS-p130Cas-like), localizes to
           focal adhesions and plays a role in regulating FAK
           activity, focal adhesion integrity, and cell spreading.
           It is most abundant in blood cells and lung tissue, and
           is also found in high levels in leukemia and ovarian
           cell lines. CAS proteins function as molecular scaffolds
           to regulate protein complexes that are involved in many
           cellular processes. They share a common domain structure
           that includes an N-terminal SH3 domain, an unstructured
           substrate domain that contains many YxxP motifs, a
           serine-rich four-helix bundle, and a FAT-like C-terminal
           domain. The SH3 domain of CAS proteins binds to diverse
           partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180,
           among others. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 32.5 bits (74), Expect = 0.020
 Identities = 13/35 (37%), Positives = 20/35 (57%), Gaps = 3/35 (8%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKD---EEHWW 146
           A YD   +  D+L F++ DIL V+ ++    E WW
Sbjct: 5   ALYDNKADCSDELAFRRGDILTVLEQNVPGSEGWW 39


>gnl|CDD|212817 cd11884, SH3_MYO15, Src Homology 3 domain of Myosin XV.  This
           subfamily is composed of proteins with similarity to
           Myosin XVa. Myosin XVa is an unconventional myosin that
           is critical for the normal growth of mechanosensory
           stereocilia of inner ear hair cells. Mutations in the
           myosin XVa gene are associated with nonsyndromic hearing
           loss. Myosin XVa contains a unique N-terminal extension
           followed by a motor domain, light chain-binding IQ
           motifs, and a tail consisting of a pair of MyTH4-FERM
           tandems separated by a SH3 domain, and a PDZ domain. SH3
           domains bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs;
           they play a role in the regulation of enzymes by
           intramolecular interactions, changing the subcellular
           localization of signal pathway components and mediate
           multiprotein complex assemblies.
          Length = 56

 Score = 32.7 bits (75), Expect = 0.022
 Identities = 15/44 (34%), Positives = 25/44 (56%), Gaps = 3/44 (6%)

Query: 220 DKTALKLEIGDIIKVTK--TNINGQWE-GELNGKTGHFPFTHVE 260
           D+T L    GD+IK+      ++  W  G L+G++G FP  +V+
Sbjct: 12  DQTLLSFHKGDVIKLLPKEGPLDPGWLFGTLDGRSGAFPKEYVQ 55


>gnl|CDD|198275 cd10412, SH2_SH2B3, Src homology 2 (SH2) domain found in SH2B
          adapter proteins (SH2B1, SH2B2, SH2B3).  SH2B3 (Lnk),
          like other members of the SH2B adapter protein family,
          contains a pleckstrin homology domain, at least one
          dimerization domain, and a C-terminal SH2 domain which
          binds to phosphorylated tyrosines in a variety of
          tyrosine kinases.  SH2B3 negatively regulates
          lymphopoiesis and early hematopoiesis. The
          lnk-deficiency results in enhanced production of B
          cells, and expansion as well as enhanced function of
          hematopoietic stem cells (HSCs), demonstrating negative
          regulatory functions of Sh2b3/Lnk in cytokine
          signaling. Sh2b3/Lnk also functions in responses
          controlled by cell adhesion and in crosstalk between
          integrin- and cytokine-mediated signaling. In general
          SH2 domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 97

 Score = 33.3 bits (76), Expect = 0.025
 Identities = 22/65 (33%), Positives = 33/65 (50%), Gaps = 5/65 (7%)

Query: 12 SWYFGMMTR-QEAQAILLSEKD-NGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNT 69
           W+ G ++R + AQ + L   D +G FLVR S T  G YVL      +  H    +++ T
Sbjct: 9  PWFHGPISRVKAAQLVQLQGPDAHGVFLVRQSETRRGEYVLTFNFQGRAKHL---RLSLT 65

Query: 70 EQQTC 74
          E+  C
Sbjct: 66 ERGQC 70


>gnl|CDD|212873 cd11940, SH3_ARHGEF5_19, Src homology 3 domain of the Rho guanine
           nucleotide exchange factors ARHGEF5 and ARHGEF19.
           ARHGEF5, also called ephexin-3 or TIM (Transforming
           immortalized mammary oncogene), is a potent activator of
           RhoA and it plays roles in regulating cell shape,
           adhesion, and migration. It binds to the SH3 domain of
           Src and is involved in regulating Src-induced podosome
           formation. ARHGEF19, also called ephexin-2 or WGEF
           (weak-similarity GEF), is highly expressed in the
           intestine, liver, heart and kidney. It activates RhoA,
           Cdc42, and Rac 1, and has been shown to activate RhoA in
           the Wnt-PCP (planar cell polarity) pathway. It is
           involved in the regulation of cell polarity and
           cytoskeletal reorganization. ARHGEF5 and ARHGEF19
           contain RhoGEF (also called Dbl-homologous or DH),
           Pleckstrin Homology (PH), and SH3 domains. The SH3
           domains of ARHGEFs play an autoinhibitory role through
           intramolecular interactions with a proline-rich region
           N-terminal to the DH domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 32.5 bits (74), Expect = 0.026
 Identities = 13/47 (27%), Positives = 24/47 (51%), Gaps = 1/47 (2%)

Query: 119 FDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNIS-GEVGSIPVPYVQ 164
           +   + D+L  +K DI++V  +  + W     +S GE G  P  +V+
Sbjct: 8   YKAQENDELTLEKADIIMVRQQSSDGWLEGVRLSDGERGWFPQSHVE 54



 Score = 30.1 bits (68), Expect = 0.17
 Identities = 20/55 (36%), Positives = 30/55 (54%), Gaps = 2/55 (3%)

Query: 209 RVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGEL--NGKTGHFPFTHVEF 261
           +V+ +R   A +   L LE  DII V + + +G  EG    +G+ G FP +HVE 
Sbjct: 1   QVQCIRSYKAQENDELTLEKADIIMVRQQSSDGWLEGVRLSDGERGWFPQSHVEE 55


>gnl|CDD|212915 cd11982, SH3_Shank1, Src homology 3 domain of SH3 and multiple
           ankyrin repeat domains protein 1.  Shank1, also called
           SSTRIP (Somatostatin receptor-interacting protein), is a
           brain-specific protein that plays a role in the
           construction of postsynaptic density (PSD) and the
           maturation of dendritic spines. Mice deficient in Shank1
           show altered PSD composition, thinner PSDs, smaller
           dendritic spines, and weaker basal synaptic
           transmission, although synaptic plasticity is normal.
           They show increased anxiety and impaired fear memory,
           but also show better spatial learning. Shank proteins
           carry scaffolding functions through multiple sites of
           protein-protein interaction in its domain architecture,
           including ankyrin (ANK) repeats, a long proline rich
           region, as well as SH3, PDZ, and SAM domains. The SH3
           domain of Shank binds GRIP, a scaffold protein that
           binds AMPA receptors and Eph receptors/ligands. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 32.3 bits (73), Expect = 0.026
 Identities = 13/32 (40%), Positives = 18/32 (56%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           + L  G+ IKV      G WEG++ G+ G FP
Sbjct: 17  ISLSKGEKIKVLSVGEGGFWEGQVKGRVGWFP 48


>gnl|CDD|212794 cd11860, SH3_DLG5, Src homology 3 domain of Disks Large homolog 5. 
           DLG5 is a multifunctional scaffold protein that is
           located at sites of cell-cell contact and is involved in
           the maintenance of cell shape and polarity. Mutations in
           the DLG5 gene are associated with Crohn's disease (CD)
           and inflammatory bowel disease (IBD). DLG5 is a member
           of the MAGUK (membrane-associated guanylate kinase)
           protein family, which is characterized by the presence
           of a core of three domains: PDZ, SH3, and guanylate
           kinase (GuK). The GuK domain in MAGUK proteins is
           enzymatically inactive; instead, the domain mediates
           protein-protein interactions and associates
           intramolecularly with the SH3 domain. DLG5 contains 4
           PDZ domains as well as an N-terminal domain of unknown
           function. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 63

 Score = 32.3 bits (74), Expect = 0.026
 Identities = 12/25 (48%), Positives = 16/25 (64%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIV 137
           V A +D    + D+L FKK+DIL V
Sbjct: 2   VRALFDRSAENEDELSFKKDDILYV 26


>gnl|CDD|212936 cd12003, SH3_EFS, Src homology 3 domain of CAS (Crk-Associated
           Substrate) scaffolding protein family member, Embryonal
           Fyn-associated Substrate.  EFS is also called HEFS,
           CASS3 (Cas scaffolding protein family member 3) or SIN
           (Src-interacting protein). It was identified based on
           interactions with the Src kinases, Fyn and Yes. It plays
           a role in thymocyte development and acts as a negative
           regulator of T cell proliferation. CAS proteins function
           as molecular scaffolds to regulate protein complexes
           that are involved in many cellular processes. They share
           a common domain structure that includes an N-terminal
           SH3 domain, an unstructured substrate domain that
           contains many YxxP motifs, a serine-rich four-helix
           bundle, and a FAT-like C-terminal domain. The SH3 domain
           of CAS proteins binds to diverse partners including FAK,
           FRNK, Pyk2, PTP-PEST, DOCK180, among others. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 62

 Score = 32.2 bits (73), Expect = 0.030
 Identities = 14/58 (24%), Positives = 28/58 (48%), Gaps = 4/58 (6%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEH---WWTAQNISGEVGSIPVPYVQKYSEG 169
           A YD     P++L F++ D+L+V+ ++      WW   ++ G+ G  P   ++     
Sbjct: 5   ALYDNAAESPEELSFRRGDVLMVLKREHGSLPGWWLC-SLHGQQGIAPANRLRLLPTA 61


>gnl|CDD|212956 cd12023, SH3_NoxO1_1, First or N-terminal Src homology 3 domain of
           Nox Organizing protein 1.  Nox Organizing protein 1
           (NoxO1) is a critical regulator of enzyme kinetics of
           the nonphagocytic NADPH oxidase Nox1, which catalyzes
           the transfer of electrons from NADPH to molecular oxygen
           to form superoxide. Nox1 is expressed in colon, stomach,
           uterus, prostate, and vascular smooth muscle cells.
           NoxO1 is involved in targeting activator subunits (such
           as NoxA1) to Nox1. It is co-localized with Nox1 in the
           membranes of resting cells and directs the subcellular
           localization of Nox1. NoxO1 contains an N-terminal Phox
           homology (PX) domain, tandem SH3 domains (N-SH3 and
           C-SH3), and a C-terminal proline-rich region (PRR). This
           model characterizes the first SH3 domain (or N-SH3) of
           NoxO1. The tandem SH3 domains of NoxO1 interact with the
           PRR of p22phox, which also complexes with Nox1. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 32.1 bits (73), Expect = 0.034
 Identities = 15/49 (30%), Positives = 24/49 (48%), Gaps = 2/49 (4%)

Query: 118 DFDGNDPDDLPFK--KNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
            F+  D  + PFK    + L V+ KD   WW  +N   ++   P PY++
Sbjct: 7   PFETKDTKNKPFKAAAQESLDVLLKDPTGWWLVENEDRQIAWFPAPYLE 55


>gnl|CDD|212717 cd11783, SH3_SH3RF_3, Third Src Homology 3 domain of SH3 domain
           containing ring finger 1 (SH3RF1), SH3RF3, and similar
           domains.  SH3RF1 (or POSH) and SH3RF3 (or POSH2) are
           scaffold proteins that function as E3 ubiquitin-protein
           ligases. They contain an N-terminal RING finger domain
           and four SH3 domains. This model represents the third
           SH3 domain, located in the middle of SH3RF1 and SH3RF3,
           and similar domains. SH3RF1 plays a role in calcium
           homeostasis through the control of the ubiquitin domain
           protein Herp. It may also have a role in regulating
           death receptor mediated and JNK mediated apoptosis.
           SH3RF3 interacts with p21-activated kinase 2 (PAK2) and
           GTP-loaded Rac1. It may play a role in regulating JNK
           mediated apoptosis in certain conditions. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 31.6 bits (72), Expect = 0.040
 Identities = 15/53 (28%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYVQ 164
            +A Y +    PD+L  +K ++  V  K ++ W+   ++ +G+ G  P  YVQ
Sbjct: 2   YVALYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTSLRTGQSGVFPGNYVQ 54


>gnl|CDD|198274 cd10411, SH2_SH2B2, Src homology 2 (SH2) domain found in SH2B
          adapter proteins (SH2B1, SH2B2, SH2B3).  SH2B2 (APS),
          like other members of the SH2B adapter protein family,
          contains a pleckstrin homology domain, at least one
          dimerization domain, and a C-terminal SH2 domain which
          binds to phosphorylated tyrosines in a variety of
          tyrosine kinases. SH2B1 and SH2B2  function in
          signaling pathways found downstream of growth hormone
          receptor and receptor tyrosine kinases, including the
          insulin, insulin-like growth factor-I (IGF-I),
          platelet-derived growth factor (PDGF), nerve growth
          factor, hepatocyte growth factor, and fibroblast growth
          factor receptors. SH2B2beta, a new isoform of SH2B2, is
          an endogenous inhibitor of SH2B1 and/or SH2B2
          (SH2B2alpha), negatively regulating insulin signaling
          and/or JAK2-mediated cellular responses. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 97

 Score = 33.1 bits (75), Expect = 0.040
 Identities = 16/50 (32%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 13 WYFGMMTRQEAQAILLS--EKDNGAFLVRDSNTILGNYVLCVKENNKVSH 60
          W+ G ++R +A  ++L+   + +G F++R S T  G YVL      K  H
Sbjct: 10 WFHGTLSRVKAAQLVLAGGPRSHGLFVIRQSETRPGEYVLTFNFQGKAKH 59


>gnl|CDD|212827 cd11894, SH3_FCHSD2_2, Second Src Homology 3 domain of FCH and
           double SH3 domains protein 2.  FCHSD2 has a domain
           structure consisting of an N-terminal F-BAR (FES-CIP4
           Homology and Bin/Amphiphysin/Rvs), two SH3, and
           C-terminal proline-rich domains. It has only been
           characterized in silico and its function is unknown. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 56

 Score = 31.8 bits (72), Expect = 0.041
 Identities = 12/21 (57%), Positives = 14/21 (66%)

Query: 240 NGQWEGELNGKTGHFPFTHVE 260
           +G WEGE NG+ G FP   VE
Sbjct: 35  DGFWEGEFNGRIGVFPSVLVE 55



 Score = 29.9 bits (67), Expect = 0.17
 Identities = 15/55 (27%), Positives = 31/55 (56%), Gaps = 4/55 (7%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKD---EEHWWTAQNISGEVGSIPVPYVQ 164
           V A YD++G   D+L F +  I+ +++K+   ++ +W  +  +G +G  P   V+
Sbjct: 2   VKALYDYEGQTDDELSFPEGAIIRILNKENQDDDGFWEGE-FNGRIGVFPSVLVE 55


>gnl|CDD|212927 cd11994, SH3_Intersectin2_4, Fourth Src homology 3 domain (or SH3D)
           of Intersectin-2.  Intersectin-2 (ITSN2) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN2 also functions as a specific GEF for Cdc42
           activation in epithelial morphogenesis, and is required
           in mitotic spindle orientation. It exists in
           alternatively spliced short and long isoforms. The short
           isoform contains two Eps15 homology domains (EH1 and
           EH2), a coiled-coil region and five SH3 domains
           (SH3A-E), while the long isoform, in addition, contains
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           homology (PH) and C2 domains. The fourth SH3 domain (or
           SH3D) of ITSN2 is expected to bind protein partners,
           similar to ITSN1 which has been shown to bind SHIP2,
           Numb, CdGAP, and N-WASP. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 59

 Score = 31.8 bits (72), Expect = 0.044
 Identities = 16/44 (36%), Positives = 23/44 (52%), Gaps = 5/44 (11%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNG-----KTGHFPFTHVEFI 262
           L L  G +I + K N +G W GEL       + G FP +HV+ +
Sbjct: 16  LSLSPGQLILILKKNSSGWWLGELQARGKKRQKGWFPASHVKLL 59


>gnl|CDD|213013 cd12080, SH3_MPP1, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 1 (or MAGUK p55 subfamily member 1).
           MPP1, also called 55 kDa erythrocyte membrane protein
           (p55), is a ubiquitously-expressed scaffolding protein
           that plays roles in regulating neutrophil polarity, cell
           shape, hair cell development, and neural development and
           patterning of the retina. It was originally identified
           as an erythrocyte protein that stabilizes the actin
           cytoskeleton to the plasma membrane by forming a complex
           with 4.1R protein and glycophorin C. MPP1 is one of
           seven vertebrate homologs of the Drosophila Stardust
           protein, which is required in establishing cell
           polarity, and it contains the three domains
           characteristic of MAGUK (membrane-associated guanylate
           kinase) proteins: PDZ, SH3, and guanylate kinase (GuK).
           In addition, it also contains the Hook (Protein 4.1
           Binding) motif in between the SH3 and GuK domains. The
           GuK domain in MAGUK proteins is enzymatically inactive;
           instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 62

 Score = 31.8 bits (72), Expect = 0.049
 Identities = 15/57 (26%), Positives = 29/57 (50%), Gaps = 10/57 (17%)

Query: 115 AKYDFDGNDPDDLP-------FKKNDILIVVSKDEEHWWTAQ---NISGEVGSIPVP 161
           A++D+D    + +P       F+  DI+ +++KD+ +WW  +   +     G IP P
Sbjct: 4   AQFDYDPKKDNLIPCKEAGLKFQTGDIIQIINKDDSNWWQGRVEGSGEESAGLIPSP 60


>gnl|CDD|212917 cd11984, SH3_Shank3, Src homology 3 domain of SH3 and multiple
           ankyrin repeat domains protein 3.  Shank3, also called
           ProSAP2 (Proline-rich synapse-associated protein 2), is
           widely expressed. It plays a role in the formation of
           dendritic spines and synapses. Haploinsufficiency of the
           Shank3 gene causes the 22q13 deletion/Phelan-McDermid
           syndrome, and variants of Shank3 have been implicated in
           autism spectrum disorder, schizophrenia, and
           intellectual disability. Shank proteins carry
           scaffolding functions through multiple sites of
           protein-protein interaction in its domain architecture,
           including ankyrin (ANK) repeats, a long proline rich
           region, as well as SH3, PDZ, and SAM domains. The SH3
           domain of Shank binds GRIP, a scaffold protein that
           binds AMPA receptors and Eph receptors/ligands. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 31.5 bits (71), Expect = 0.054
 Identities = 13/32 (40%), Positives = 19/32 (59%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           ++L  G+ +KV      G WEG + G+TG FP
Sbjct: 17  IQLNRGERVKVLSIGEGGFWEGTVKGRTGWFP 48


>gnl|CDD|212902 cd11969, SH3_PLCgamma2, Src homology 3 domain of Phospholipase C
           (PLC) gamma 2.  PLCgamma2 is primarily expressed in
           haematopoietic cells, specifically in B cells. It is
           activated by tyrosine phosphorylation by B cell receptor
           (BCR) kinases and is recruited to the plasma membrane
           where its substrate is located. It is required in
           pre-BCR signaling and in the maturation of B cells. PLCs
           catalyze the hydrolysis of phosphatidylinositol
           (4,5)-bisphosphate [PtdIns(4,5)P2] to produce
           Ins(1,4,5)P3 and diacylglycerol (DAG). Ins(1,4,5)P3
           initiates the calcium signaling cascade while DAG
           functions as an activator of PKC. PLCgamma contains a
           Pleckstrin homology (PH) domain followed by an
           elongation factor (EF) domain, two catalytic regions of
           PLC domains that flank two tandem SH2 domains, followed
           by a SH3 domain and C2 domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 31.3 bits (71), Expect = 0.061
 Identities = 13/34 (38%), Positives = 18/34 (52%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWW 146
           V A YD+     D+L F K  ++  VSK+   WW
Sbjct: 2   VKALYDYRAKRSDELSFCKGALIHNVSKETGGWW 35


>gnl|CDD|212935 cd12002, SH3_NEDD9, Src homology 3 domain of CAS (Crk-Associated
           Substrate) scaffolding protein family member, Neural
           precursor cell Expressed, Developmentally Down-regulated
           9.  NEDD9 is also called human enhancer of filamentation
           1 (HEF1) or CAS-L (Crk-associated substrate in
           lymphocyte). It was first described as a gene
           predominantly expressed in early embryonic brain, and
           was also isolated from a screen of human proteins that
           regulate filamentous budding in yeast, and as a tyrosine
           phosphorylated protein in lymphocytes. It promotes
           metastasis in different solid tumors. NEDD9 localizes in
           focal adhesions and associates with FAK and Abl kinase.
           It also interacts with SMAD3 and the proteasomal
           machinery which allows its rapid turnover; these
           interactions are not shared by other CAS proteins. CAS
           proteins function as molecular scaffolds to regulate
           protein complexes that are involved in many cellular
           processes. They share a common domain structure that
           includes an N-terminal SH3 domain, an unstructured
           substrate domain that contains many YxxP motifs, a
           serine-rich four-helix bundle, and a FAT-like C-terminal
           domain. The SH3 domain of CAS proteins binds to diverse
           partners including FAK, FRNK, Pyk2, PTP-PEST, DOCK180,
           among others. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 31.1 bits (70), Expect = 0.064
 Identities = 16/48 (33%), Positives = 24/48 (50%), Gaps = 4/48 (8%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDE---EHWWTAQNISGEVGSIP 159
           A YD      ++L F+K DIL V+ ++    E WW   ++ G  G  P
Sbjct: 4   ALYDNVPECAEELAFRKGDILTVIEQNTGGLEGWWLC-SLHGRQGIAP 50


>gnl|CDD|212895 cd11962, SH3_Abp1_fungi_C1, First C-terminal Src homology 3 domain
           of Fungal Actin-binding protein 1.  Abp1 is an adaptor
           protein that functions in receptor-mediated endocytosis
           and vesicle trafficking. It contains an N-terminal
           actin-binding module, the actin-depolymerizing factor
           (ADF) homology domain, a central proline-rich region,
           and a C-terminal SH3 domain (many yeast Abp1 proteins
           contain two C-terminal SH3 domains). Yeast Abp1 also
           contains two acidic domains that bind directly to the
           Arp2/3 complex, which is required to initiate actin
           polymerization. The SH3 domain of yeast Abp1 binds and
           localizes the kinases, Ark1p and Prk1p, which facilitate
           actin patch disassembly following vesicle
           internalization. It also mediates the localization to
           the actin patch of the synaptojanin-like protein, Sjl2p,
           which plays a key role in endocytosis. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 54

 Score = 31.3 bits (71), Expect = 0.065
 Identities = 13/48 (27%), Positives = 26/48 (54%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           YD++ ++ +++   + +I+  +   +E WW   N  GE G  P  YV+
Sbjct: 6   YDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGTNSKGESGLFPSNYVE 53


>gnl|CDD|198222 cd10359, SH2_SH3BP2, Src homology 2 domain found in c-Abl SH3
          domain-binding protein-2 (SH3BP2).  The adaptor protein
          3BP2/SH3BP2 plays a regulatory role in signaling from
          immunoreceptors. The protein-tyrosine kinase Syk
          phosphorylates 3BP2 which results in the activation of
          Rac1 through the interaction with the SH2 domain of
          Vav1 and induces the binding to the SH2 domain of the
          upstream protein-tyrosine kinase Lyn and enhances its
          kinase activity. 3BP2 has a positive regulatory role in
          IgE-mediated mast cell activation. In lymphocytes,
          engagement of T cell or B cell receptors triggers
          tyrosine phosphorylation of 3BP2. Suppression of the
          3BP2 expression by siRNA results in the inhibition of T
          cell or B cell receptor-mediated activation of NFAT.
          3BP2 is required for the proliferation of B cells and B
          cell receptor signaling. Mutations in the 3BP2 gene are
          responsible for cherubism resulting in excessive bone
          resorption in the jaw.  In general SH2 domains are
          involved in signal transduction. They typically bind
          pTyr-containing ligands via two surface pockets, a pTyr
          and hydrophobic binding pocket, allowing proteins with
          SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 101

 Score = 32.3 bits (73), Expect = 0.069
 Identities = 23/87 (26%), Positives = 36/87 (41%), Gaps = 12/87 (13%)

Query: 18 MTRQEAQAIL-----LSEKDNGAFLVRDSNTILGNYVLCV--KENNKVSHYIINKITNTE 70
          M  +E + +           +G + +R+S+T  G  VL V      KV +Y I +    +
Sbjct: 7  MESREVERLFKATSPKGGPQDGLYCIRNSST-KGGKVLVVWDGGAEKVRNYRIFE----K 61

Query: 71 QQTCYKIGDKTFSDLPSLLAFYKVHYL 97
              Y    + FS L SL+  Y  H L
Sbjct: 62 DCKFYLHEREVFSSLGSLVEHYATHVL 88


>gnl|CDD|198174 cd09918, SH2_Nterm_SPT6_like, N-terminal Src homology 2 (SH2)
          domain found in Spt6.  N-terminal SH2 domain in Spt6.
          Spt6 is an essential transcription elongation factor
          and histone chaperone that binds the C-terminal repeat
          domain (CTD) of RNA polymerase II. Spt6 contains a
          tandem SH2 domain with a novel structure and
          CTD-binding mode. The tandem SH2 domain binds to a
          serine 2-phosphorylated CTD peptide in vitro, whereas
          its N-terminal SH2 subdomain does not. CTD binding
          requires a positively charged crevice in the C-terminal
          SH2 subdomain, which lacks the canonical
          phospho-binding pocket of SH2 domains. The tandem SH2
          domain is apparently required for transcription
          elongation in vivo as its deletion in cells is lethal
          in the presence of 6-azauracil.  In general SH2 domains
          are involved in signal transduction.  They typically
          bind pTyr-containing ligands via two surface pockets, a
          pTyr and hydrophobic binding pocket, allowing proteins
          with SH2 domains to localize to tyrosine phosphorylated
          sites.
          Length = 85

 Score = 31.8 bits (73), Expect = 0.079
 Identities = 19/83 (22%), Positives = 35/83 (42%), Gaps = 5/83 (6%)

Query: 14 YFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK-ENNKVSHYII---NKITNT 69
           F  +  ++A+A  L  KD G  ++R S+  + +  +  K  +    H  I   NK    
Sbjct: 4  LFKNVNYKQAEA-YLKSKDVGEVVIRPSSKGVDHLTVTWKVADGVYQHIDIEELNKENPF 62

Query: 70 EQQTCYKIGDKTFSDLPSLLAFY 92
                 IG + + DL  ++A +
Sbjct: 63 SLGKELIIGGEEYEDLDEIIARF 85


>gnl|CDD|212971 cd12038, SH3_MPP6, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 6 (or MAGUK p55 subfamily member 6).
           MPP6, also called Veli-associated MAGUK 1 (VAM-1) or
           PALS2, is a scaffolding protein that binds to Veli-1, a
           homolog of Caenorhabditis Lin-7. It is one of seven
           vertebrate homologs of the Drosophila Stardust protein,
           which is required in establishing cell polarity, and it
           contains two L27 domains followed by the core of three
           domains characteristic of MAGUK (membrane-associated
           guanylate kinase) proteins: PDZ, SH3, and guanylate
           kinase (GuK). In addition, it also contains the Hook
           (Protein 4.1 Binding) motif in between the SH3 and GuK
           domains. The GuK domain in MAGUK proteins is
           enzymatically inactive; instead, the domain mediates
           protein-protein interactions and associates
           intramolecularly with the SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 61

 Score = 31.2 bits (70), Expect = 0.080
 Identities = 13/39 (33%), Positives = 24/39 (61%), Gaps = 2/39 (5%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNIS--GEVGSIPVPYV 163
           L F K +IL +V++++ +WW A ++   G  G IP  ++
Sbjct: 23  LKFSKGEILQIVNREDPNWWQASHVKEGGSAGLIPSQFL 61


>gnl|CDD|212802 cd11869, SH3_p40phox, Src Homology 3 domain of the p40phox subunit
           of NADPH oxidase.  p40phox, also called Neutrophil
           cytosol factor 4 (NCF-4), is a cytosolic subunit of the
           phagocytic NADPH oxidase complex (also called Nox2 or
           gp91phox) which plays a crucial role in the cellular
           response to bacterial infection. NADPH oxidase catalyzes
           the transfer of electrons from NADPH to oxygen during
           phagocytosis forming superoxide and reactive oxygen
           species. p40phox positively regulates NADPH oxidase in
           both phosphatidylinositol-3-phosphate (PI3P)-dependent
           and PI3P-independent manner. It contains an N-terminal
           PX domain, a central SH3 domain, and a C-terminal PB1
           domain that interacts with p67phox. The SH3 domain of
           p40phox binds to canonical polyproline and noncanonical
           motifs at the C-terminus of p47phox. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 54

 Score = 30.9 bits (70), Expect = 0.084
 Identities = 16/43 (37%), Positives = 24/43 (55%), Gaps = 2/43 (4%)

Query: 221 KTALKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVEFI 262
           K  L  + GD+I +  + +N  W EG + G TG FP + V+ I
Sbjct: 13  KLELNFKAGDVIFLL-SRVNKDWLEGTVRGATGIFPLSFVKII 54



 Score = 29.0 bits (65), Expect = 0.38
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A +DF GN   +L FK  D++ ++S+  + W     + G  G  P+ +V+
Sbjct: 4   ALFDFTGNSKLELNFKAGDVIFLLSRVNKDWLEG-TVRGATGIFPLSFVK 52


>gnl|CDD|212954 cd12021, SH3_p47phox_1, First or N-terminal Src homology 3 domain
           of the p47phox subunit of NADPH oxidase, also called
           Neutrophil Cytosolic Factor 1.  p47phox, or NCF1, is a
           cytosolic subunit of the phagocytic NADPH oxidase
           complex (also called Nox2 or gp91phox), which plays a
           key role in the ability of phagocytes to defend against
           bacterial infections. NADPH oxidase catalyzes the
           transfer of electrons from NADPH to oxygen during
           phagocytosis forming superoxide and reactive oxygen
           species. p47phox is required for activation of NADH
           oxidase and plays a role in translocation. It contains
           an N-terminal Phox homology (PX) domain, tandem SH3
           domains (N-SH3 and C-SH3), a polybasic/autoinhibitory
           region, and a C-terminal proline-rich region (PRR). This
           model characterizes the first SH3 domain (or N-SH3) of
           p47phox. In its inactive state, the tandem SH3 domains
           interact intramolecularly with the autoinhibitory
           region; upon activation, the tandem SH3 domains are
           exposed through a conformational change, resulting in
           their binding to the PRR of p22phox and the activation
           of NADPH oxidase. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 53

 Score = 30.7 bits (69), Expect = 0.086
 Identities = 15/53 (28%), Positives = 28/53 (52%), Gaps = 3/53 (5%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           + IA  D++ +   ++  K  D++ VV K E  WW  Q +  + G +P  Y++
Sbjct: 3   RAIA--DYEKSSKSEMALKTGDVVEVVEKSENGWWFCQ-LKAKRGWVPASYLE 52



 Score = 28.8 bits (64), Expect = 0.51
 Identities = 15/50 (30%), Positives = 29/50 (58%), Gaps = 3/50 (6%)

Query: 214 RVPNAYDKTA---LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           R    Y+K++   + L+ GD+++V + + NG W  +L  K G  P +++E
Sbjct: 3   RAIADYEKSSKSEMALKTGDVVEVVEKSENGWWFCQLKAKRGWVPASYLE 52


>gnl|CDD|212744 cd11810, SH3_RUSC1_like, Src homology 3 domain of RUN and SH3
           domain-containing proteins 1 and 2.  RUSC1 and RUSC2,
           that were originally characterized in silico. They are
           adaptor proteins consisting of RUN, leucine zipper, and
           SH3 domains. RUSC1, also called NESCA (New molecule
           containing SH3 at the carboxy-terminus), is highly
           expressed in the brain and is translocated to the
           nuclear membrane from the cytoplasm upon stimulation
           with neurotrophin. It plays a role in facilitating
           neurotrophin-dependent neurite outgrowth. It also
           interacts with NEMO (or IKKgamma) and may function in
           NEMO-mediated activation of NF-kB. RUSC2, also called
           Iporin, is expressed ubiquitously with highest amounts
           in the brain and testis. It interacts with the small
           GTPase Rab1 and the Golgi matrix protein GM130, and may
           function in linking GTPases to certain intracellular
           signaling pathways. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 50

 Score = 30.5 bits (69), Expect = 0.091
 Identities = 11/34 (32%), Positives = 17/34 (50%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHW 145
            V A       D   L F+K DIL V+++ ++ W
Sbjct: 1   VVRALCHHVATDSGQLSFRKGDILRVIARVDDDW 34


>gnl|CDD|212821 cd11888, SH3_ARHGAP9_like, Src Homology 3 domain of Rho
           GTPase-activating protein 9 and similar proteins.  This
           subfamily is composed of Rho GTPase-activating proteins
           including mammalian ARHGAP9, and vertebrate ARHGAPs 12
           and 27. RhoGAPs (or ARHGAPs) bind to Rho proteins and
           enhance the hydrolysis rates of bound GTP. ARHGAP9
           functions as a GAP for Rac and Cdc42, but not for RhoA.
           It negatively regulates cell migration and adhesion. It
           also acts as a docking protein for the MAP kinases Erk2
           and p38alpha, and may facilitate cross-talk between the
           Rho GTPase and MAPK pathways to control actin
           remodeling. ARHGAP27, also called CAMGAP1, shows GAP
           activity towards Rac1 and Cdc42. It binds the adaptor
           protein CIN85 and may play a role in clathrin-mediated
           endocytosis. ARHGAP12 has been shown to display GAP
           activity towards Rac1. It plays a role in regulating
           HFG-driven cell growth and invasiveness. ARHGAPs in this
           subfamily contain SH3, WW, Pleckstin homology (PH), and
           RhoGAP domains. SH3 domains bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 54

 Score = 30.4 bits (69), Expect = 0.100
 Identities = 9/37 (24%), Positives = 18/37 (48%), Gaps = 2/37 (5%)

Query: 112 KVIAKYDFD--GNDPDDLPFKKNDILIVVSKDEEHWW 146
            V+  Y F+  G D   +  K+ +  +++ K  + WW
Sbjct: 1   YVVVLYPFEYTGKDGRKVSIKEGERFLLLKKSNDDWW 37


>gnl|CDD|212903 cd11970, SH3_PLCgamma1, Src homology 3 domain of Phospholipase C
           (PLC) gamma 1.  PLCgamma1 is widely expressed and is
           essential in growth and development. It is activated by
           the TrkA receptor tyrosine kinase and functions as a key
           regulator of cell differentiation. It is also the
           predominant PLCgamma in T cells and is required for T
           cell and NK cell function. PLCs catalyze the hydrolysis
           of phosphatidylinositol (4,5)-bisphosphate
           [PtdIns(4,5)P2] to produce Ins(1,4,5)P3 and
           diacylglycerol (DAG). Ins(1,4,5)P3 initiates the calcium
           signaling cascade while DAG functions as an activator of
           PKC. PLCgamma contains a Pleckstrin homology (PH) domain
           followed by an elongation factor (EF) domain, two
           catalytic regions of PLC domains that flank two tandem
           SH2 domains, followed by a SH3 domain and C2 domain. The
           SH3 domain of PLCgamma1 directly interacts with
           dynamin-1 and can serve as a guanine nucleotide exchange
           factor (GEF). It also interacts with Cbl, inhibiting its
           phosphorylation and activity. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 60

 Score = 30.7 bits (69), Expect = 0.10
 Identities = 14/34 (41%), Positives = 18/34 (52%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWW 146
           V A +D+     D+L F KN I+  V K E  WW
Sbjct: 6   VKALFDYKAQREDELTFTKNAIIQNVEKQEGGWW 39


>gnl|CDD|213010 cd12077, SH3_Tks5_2, Second Src homology 3 domain of Tyrosine
           kinase substrate with five SH3 domains.  Tks5, also
           called SH3 and PX domain-containing protein 2A
           (SH3PXD2A) or Five SH (FISH), is a scaffolding protein
           and Src substrate that is localized in podosomes, which
           are electron-dense structures found in Src-transformed
           fibroblasts, osteoclasts, macrophages, and some invasive
           cancer cells. It binds and regulates some members of the
           ADAMs family of transmembrane metalloproteases, which
           function as sheddases and mediators of cell and matrix
           interactions. It is required for podosome formation,
           degradation of the extracellular matrix, and cancer cell
           invasion. Tks5 contains an N-terminal Phox homology (PX)
           domain and five SH3 domains. This model characterizes
           the second SH3 domain of Tks5. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 54

 Score = 30.8 bits (69), Expect = 0.10
 Identities = 15/55 (27%), Positives = 27/55 (49%), Gaps = 1/55 (1%)

Query: 111 EKVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           EK +    +     D++ F+K   + V+ K+ E WW  +   G+ G  P  Y++K
Sbjct: 1   EKYVTVQPYTSQGKDEIGFEKGVTVEVIQKNLEGWWYIRY-LGKEGWAPASYLKK 54


>gnl|CDD|212708 cd11774, SH3_Sla1p_2, Second Src Homology 3 domain of the fungal
           endocytic adaptor protein Sla1p.  Sla1p facilitates
           endocytosis by playing a role as an adaptor protein in
           coupling components of the actin cytoskeleton to the
           endocytic machinery. It interacts with Abp1p, Las17p and
           Pan1p, which are activator proteins of actin-related
           protein 2/3 (Arp2/3). Sla1p contains multiple domains
           including three SH3 domains, a SAM (sterile alpha motif)
           domain, and a Sla1 homology domain 1 (SHD1), which binds
           to the NPFXD motif that is found in many integral
           membrane proteins such as the Golgi-localized
           Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and
           Dnf1p. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 30.5 bits (69), Expect = 0.11
 Identities = 13/52 (25%), Positives = 22/52 (42%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +  A YD+D    ++L F + D L V    +  W        + G +P  Y+
Sbjct: 1   QAKALYDYDKQTEEELSFNEGDTLDVYDDSDSDWILVGFNGTQFGFVPANYI 52


>gnl|CDD|212876 cd11943, SH3_JIP1, Src homology 3 domain of JNK-interacting protein
           1.  JNK-interacting protein 1 (JIP1) is also called
           Islet-brain 1 (IB1) or Mitogen-activated protein kinase
           8-interacting protein 1 (MAPK8IP1). It is highly
           expressed in neurons, where it functions as an adaptor
           linking motor to cargo during axonal transport. It also
           affects microtubule dynamics in neurons. JIP1 is also
           found in pancreatic beta-cells, where it is involved in
           regulating insulin secretion. In addition to a JNK
           binding domain, JIP1 also contains SH3 and
           Phosphotyrosine-binding (PTB) domains. Its SH3 domain
           homodimerizes at the interface usually involved in
           proline-rich ligand recognition, despite the lack of
           this motif in the domain itself. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 30.7 bits (69), Expect = 0.11
 Identities = 16/49 (32%), Positives = 27/49 (55%), Gaps = 1/49 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPY 162
           A + F    PD+L  + +D L+V  + E++W+ A N+ +G  G  P  Y
Sbjct: 4   AVFRFVPRHPDELELEVDDPLLVEVQAEDYWYEAYNMRTGARGIFPAYY 52


>gnl|CDD|212711 cd11777, SH3_CIP4_Bzz1_like, Src Homology 3 domain of
           Cdc42-Interacting Protein 4, Bzz1 and similar domains.
           This subfamily is composed of Cdc42-Interacting Protein
           4 (CIP4) and similar proteins such as Formin Binding
           Protein 17 (FBP17) and FormiN Binding Protein 1-Like
           (FNBP1L), as well as yeast Bzz1 (or Bzz1p). CIP4 and
           FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich
           syndrome protein (WASP) and function in endocytosis.
           CIP4 and FBP17 bind to the Fas ligand and may be
           implicated in the inflammatory response. CIP4 may also
           play a role in phagocytosis. Bzz1 is also a
           WASP/Las17-interacting protein involved in endocytosis
           and trafficking to the vacuole. It physically interacts
           with type I myosins and functions in the early steps of
           endocytosis. Members of this subfamily contain an
           N-terminal F-BAR (FES-CIP4 Homology and
           Bin/Amphiphysin/Rvs) domain as well as at least one
           C-terminal SH3 domain. Bzz1 contains a second SH3 domain
           at the C-terminus. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 30.7 bits (69), Expect = 0.11
 Identities = 14/51 (27%), Positives = 26/51 (50%), Gaps = 1/51 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWT-AQNISGEVGSIPVPYVQ 164
           A Y F G+    +   + + L +V +D+   WT  +  +GE G +P  Y++
Sbjct: 4   ALYAFVGSSEGTISMTEGEKLSLVEEDKGDGWTRVRRDTGEEGYVPTSYIR 54


>gnl|CDD|212856 cd11923, SH3_Sorbs2_2, Second Src Homology 3 domain of Sorbin and
           SH3 domain containing 2 (Sorbs2), also called
           Arg-binding protein 2 (ArgBP2).  Sorbs2 or ArgBP2 is an
           adaptor protein containing one sorbin homology (SoHo)
           and three SH3 domains. It regulates actin-dependent
           processes including cell adhesion, morphology, and
           migration. It is expressed in many tissues and is
           abundant in the heart. Like vinexin, it is found in
           focal adhesion where it interacts with vinculin and
           afadin. It also localizes in epithelial cell stress
           fibers and in cardiac muscle cell Z-discs. Sorbs2 has
           been implicated to play roles in the signaling of c-Arg,
           Akt, and Pyk2. Other interaction partners of Sorbs2
           include c-Abl, flotillin, spectrin, dynamin 1/2,
           synaptojanin, PTP-PEST, among others. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 57

 Score = 30.7 bits (69), Expect = 0.12
 Identities = 15/55 (27%), Positives = 33/55 (60%), Gaps = 3/55 (5%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISG--EVGSIPVPYVQ 164
           + +AKY+F+ +   +L  +K D ++++ + +++W+  + I G    G  PV YV+
Sbjct: 2   EAVAKYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGK-IPGTNRQGIFPVSYVE 55


>gnl|CDD|212822 cd11889, SH3_Cyk3p-like, Src Homology 3 domain of Cytokinesis
           protein 3 and similar proteins.  Cytokinesis protein 3
           (Cyk3 or Cyk3p) is a component of the actomyosin ring
           independent cytokinesis pathway in yeast. It interacts
           with Inn1 and facilitates its recruitment to the bud
           neck, thereby promoting cytokinesis. Cyk3p contains an
           N-terminal SH3 domain and a C-terminal
           transglutaminase-like domain. The Cyk3p SH3 domain binds
           to the C-terminal proline-rich region of Inn1. SH3
           domains bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs;
           they play a role in the regulation of enzymes by
           intramolecular interactions, changing the subcellular
           localization of signal pathway components and mediate
           multiprotein complex assemblies.
          Length = 53

 Score = 30.2 bits (68), Expect = 0.13
 Identities = 17/53 (32%), Positives = 27/53 (50%), Gaps = 1/53 (1%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYV 163
           KV A Y + G    DL F + D++ V+S  +  WW+ +   +G  G  P  +V
Sbjct: 1   KVKAVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLRRNGAEGIFPSNFV 53


>gnl|CDD|212970 cd12037, SH3_MPP2, Src Homology 3 domain of Membrane Protein,
           Palmitoylated 2 (or MAGUK p55 subfamily member 2).  MPP2
           is a scaffolding protein that interacts with the
           non-receptor tyrosine kinase c-Src in epithelial cells
           to negatively regulate its activity and morphological
           function. It is one of seven vertebrate homologs of the
           Drosophila Stardust protein, which is required in
           establishing cell polarity, and it contains two L27
           domains followed by the core of three domains
           characteristic of MAGUK (membrane-associated guanylate
           kinase) proteins: PDZ, SH3, and guanylate kinase (GuK).
           In addition, it also contains the Hook (Protein 4.1
           Binding) motif in between the SH3 and GuK domains. The
           GuK domain in MAGUK proteins is enzymatically inactive;
           instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 59

 Score = 30.3 bits (68), Expect = 0.13
 Identities = 12/34 (35%), Positives = 22/34 (64%), Gaps = 1/34 (2%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNIS-GEVGSIP 159
           L F+  D+L +V++++ +WW A ++  G  G IP
Sbjct: 23  LKFRAGDLLQIVNQEDPNWWQACHVEGGSAGLIP 56


>gnl|CDD|212854 cd11921, SH3_Vinexin_1, First Src Homology 3 domain of Vinexin,
           also called Sorbin and SH3 domain containing 3 (Sorbs3).
            Vinexin is also called Sorbs3, SH3P3, and
           SH3-containing adapter molecule 1 (SCAM-1). It is an
           adaptor protein containing one sorbin homology (SoHo)
           and three SH3 domains. Vinexin was first identified as a
           vinculin binding protein; it is co-localized with
           vinculin at cell-ECM and cell-cell adhesion sites. There
           are several splice variants of vinexin: alpha, which
           contains the SoHo and three SH3 domains and displays
           tissue-specific expression; and beta, which contains
           only the three SH3 domains and is widely expressed.
           Vinexin alpha stimulates the accumulation of F-actin at
           focal contact sites. Vinexin also promotes keratinocyte
           migration and wound healing. The SH3 domains of vinexin
           have been reported to bind a number of ligands including
           vinculin, WAVE2, DLG5, Abl, and Cbl. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 55

 Score = 30.3 bits (68), Expect = 0.14
 Identities = 16/40 (40%), Positives = 25/40 (62%), Gaps = 2/40 (5%)

Query: 224 LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFPFTHVEFI 262
           L L+ GDI+ + K  ++  W EGE +G+ G FP  +VE +
Sbjct: 17  LTLQKGDIVYIHK-EVDKNWLEGEHHGRVGIFPANYVEVL 55



 Score = 28.7 bits (64), Expect = 0.53
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
            K+DF    P +L  +K DI+ +  + +++W   ++  G VG  P  YV+
Sbjct: 5   LKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEH-HGRVGIFPANYVE 53


>gnl|CDD|212752 cd11818, SH3_Eve1_5, Fifth Src homology 3 domain of ADAM-binding
           protein Eve-1.  Eve-1, also called SH3 domain-containing
           protein 19 (SH3D19) or EEN-binding protein (EBP), exists
           in multiple alternatively spliced isoforms. The longest
           isoform contains five SH3 domain in the C-terminal
           region and seven proline-rich motifs in the N-terminal
           region. It is abundantly expressed in skeletal muscle
           and heart, and may be involved in regulating the
           activity of ADAMs (A disintegrin and metalloproteases).
           Eve-1 interacts with EEN, an endophilin involved in
           endocytosis and may be the target of the MLL-EEN fusion
           protein that is implicated in leukemogenesis. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 50

 Score = 30.1 bits (68), Expect = 0.14
 Identities = 19/49 (38%), Positives = 27/49 (55%), Gaps = 3/49 (6%)

Query: 115 AKYDFDGNDPDDLPFKKNDILI-VVSKDEEHWWTAQNISGEVGSIPVPY 162
           A YDF G + D+L FK  DI+  + S DEE  W +  + G+ G  P  +
Sbjct: 4   ALYDFTGENEDELSFKAGDIITELESIDEE--WMSGELRGKSGIFPKNF 50



 Score = 26.7 bits (59), Expect = 2.3
 Identities = 18/43 (41%), Positives = 24/43 (55%), Gaps = 7/43 (16%)

Query: 219 YDKTA-----LKLEIGDIIKVTKTNINGQW-EGELNGKTGHFP 255
           YD T      L  + GDII   ++ I+ +W  GEL GK+G FP
Sbjct: 6   YDFTGENEDELSFKAGDIITELES-IDEEWMSGELRGKSGIFP 47


>gnl|CDD|212780 cd11846, SH3_Srms, Src homology 3 domain of Srms Protein Tyrosine
           Kinase.  Src-related kinase lacking C-terminal
           regulatory tyrosine and N-terminal myristoylation sites
           (Srms) is a cytoplasmic (or non-receptor) PTK with
           limited homology to Src kinases. Src kinases in general
           contain an N-terminal SH4 domain with a myristoylation
           site, followed by SH3 and SH2 domains, a tyr kinase
           domain, and a regulatory C-terminal region containing a
           conserved tyr; they are activated by autophosphorylation
           at the tyr kinase domain, but are negatively regulated
           by phosphorylation at the C-terminal tyr by Csk
           (C-terminal Src Kinase). However, Srms lacks the
           N-terminal myristoylation sites. Src proteins are
           involved in signaling pathways that regulate cytokine
           and growth factor responses, cytoskeleton dynamics, cell
           proliferation, survival, and differentiation. The SH3
           domain of Src kinases contributes to substrate
           recruitment by binding adaptor proteins/substrates, and
           regulation of kinase activity through an intramolecular
           interaction. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 30.1 bits (68), Expect = 0.15
 Identities = 15/55 (27%), Positives = 29/55 (52%), Gaps = 3/55 (5%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISG--EVGSIPVPYVQK 165
             A YDF      +L  ++ D L V+ ++ ++ + A+ ++G  E G +P  YV +
Sbjct: 2   FTALYDFTARSTHELSVEQGDKLCVIEEEGDYIF-ARKLTGNPESGLVPASYVAQ 55


>gnl|CDD|212923 cd11990, SH3_Intersectin2_2, Second Src homology 3 domain (or SH3B)
           of Intersectin-2.  Intersectin-2 (ITSN2) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN2 also functions as a specific GEF for Cdc42
           activation in epithelial morphogenesis, and is required
           in mitotic spindle orientation. It exists in
           alternatively spliced short and long isoforms. The short
           isoform contains two Eps15 homology domains (EH1 and
           EH2), a coiled-coil region and five SH3 domains
           (SH3A-E), while the long isoform, in addition, contains
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           homology (PH) and C2 domains. The second SH3 domain (or
           SH3B) of ITSN2 is expected to bind protein partners,
           similar to ITSN1 which has been shown to bind WNK and
           CdGAP. SH3 domains are protein interaction domains that
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 29.6 bits (66), Expect = 0.19
 Identities = 16/38 (42%), Positives = 22/38 (57%), Gaps = 2/38 (5%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           L F KNDI I V + +E+WW  + + G  G  P  YV+
Sbjct: 16  LNFSKNDI-ITVLEQQENWWFGE-VHGGRGWFPKSYVK 51



 Score = 25.8 bits (56), Expect = 4.8
 Identities = 13/31 (41%), Positives = 19/31 (61%), Gaps = 1/31 (3%)

Query: 230 DIIKVTKTNINGQWEGELNGKTGHFPFTHVE 260
           DII V +   N  W GE++G  G FP ++V+
Sbjct: 22  DIITVLEQQEN-WWFGEVHGGRGWFPKSYVK 51


>gnl|CDD|212926 cd11993, SH3_Intersectin1_4, Fourth Src homology 3 domain (or SH3D)
           of Intersectin-1.  Intersectin-1 (ITSN1) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN1 localizes in membranous organelles, CCPs, the
           Golgi complex, and may be involved in the cell membrane
           trafficking system. It exists in alternatively spliced
           short and long isoforms. The short isoform contains two
           Eps15 homology domains (EH1 and EH2), a coiled-coil
           region and five SH3 domains (SH3A-E), while the long
           isoform, in addition, contains RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin homology (PH) and C2
           domains. The fourth SH3 domain (or SH3D) of ITSN1 has
           been shown to bind SHIP2, Numb, CdGAP, and N-WASP. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 65

 Score = 30.1 bits (67), Expect = 0.24
 Identities = 16/44 (36%), Positives = 22/44 (50%), Gaps = 5/44 (11%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGK-----TGHFPFTHVEFI 262
           L L  G +I + K N  G WEGEL  +      G FP  +V+ +
Sbjct: 20  LTLAPGQLILIRKKNPGGWWEGELQARGKKRQIGWFPANYVKLL 63


>gnl|CDD|212745 cd11811, SH3_CHK, Src Homology 3 domain of CSK homologous kinase.
           CHK is also referred to as megakaryocyte-associated
           tyrosine kinase (Matk). It inhibits Src kinases using a
           noncatalytic mechanism by simply binding to them. As a
           negative regulator of Src kinases, Chk may play
           important roles in cell proliferation, survival, and
           differentiation, and consequently, in cancer development
           and progression. To inhibit Src kinases that are
           anchored to the plasma membrane, CHK is translocated to
           the membrane via binding to specific transmembrane
           proteins, G-proteins, or adaptor proteins near the
           membrane. CHK also plays a role in neural
           differentiation in a manner independent of Src by
           enhancing MAPK activation via Ras-mediated signaling. It
           is a cytoplasmic (or nonreceptor) tyr kinase containing
           the Src homology domains, SH3 and SH2, N-terminal to the
           catalytic tyr kinase domain. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 59

 Score = 29.8 bits (67), Expect = 0.24
 Identities = 17/47 (36%), Positives = 24/47 (51%), Gaps = 2/47 (4%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEH-WWTAQ-NISGEVGSI 158
           + K D     P +L F K DI+ +V   E   W+ A+ N SGE G +
Sbjct: 5   VTKKDHTKPKPGELAFHKGDIVTIVETCERKGWYRARHNTSGEEGLV 51


>gnl|CDD|198220 cd10357, SH2_ShkD_ShkE, Src homology 2 (SH2) domain found in SH2
          domain-bearing protein kinases D and E (ShkD and ShkE).
           SH2-bearing genes cloned from Dictyostelium include
          two transcription factors, STATa and STATc, and a
          signaling factor, SHK1 (shkA). A database search of the
          Dictyostelium discoideum genome revealed two additional
          putative STAT sequences, dd-STATb and dd-STATd, and
          four additional putative SHK genes, dd-SHK2 (shkB),
          dd-SHK3 (shkC), dd-SHK4 (shkD), and dd-SHK5 (shkE).
          This model contains members of shkD and shkE. All of
          the SHK members are most closely related to the protein
          kinases found in plants.  However these kinases in
          plants are not conjugated to any SH2 or SH2-like
          sequences. Alignment data indicates that the SHK SH2
          domains carry some features of the STAT SH2 domains in
          Dictyostelium. When STATc's linker domain was used for
          a BLAST search, the sequence between the protein kinase
          domain and the SH2 domain (the linker) of SHK was
          recovered, suggesting a close relationship among these
          molecules within this region. SHK's linker domain is
          predicted to contain an alpha-helix which is indeed
          homologous to that of STAT. Based on the phylogenetic
          alignment, SH2 domains can be grouped into two
          categories, STAT-type and Src-type. SHK family members
          are in between, but are closer to the STAT-type which
          indicates a close relationship between SHK and STAT
          families in their SH2 domains and further supports the
          notion that SHKs linker-SH2 domain evolved from STAT or
          STATL (STAT-like Linker-SH2) domain found in plants. In
          SHK, STAT, and SPT6, the linker-SH2 domains all reside
          exclusively in the C-terminal regions.  In general SH2
          domains are involved in signal transduction.  They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 87

 Score = 30.2 bits (68), Expect = 0.26
 Identities = 13/34 (38%), Positives = 20/34 (58%), Gaps = 1/34 (2%)

Query: 10 RNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNT 43
            SW+ G ++R EA+  L    + G FL+R S+T
Sbjct: 9  AKSWFHGDISRDEAEKRLRGRPE-GTFLIRLSST 41


>gnl|CDD|212920 cd11987, SH3_Intersectin1_1, First Src homology 3 domain (or SH3A)
           of Intersectin-1.  Intersectin-1 (ITSN1) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN1 localizes in membranous organelles, CCPs, the
           Golgi complex, and may be involved in the cell membrane
           trafficking system. It exists in alternatively spliced
           short and long isoforms. The short isoform contains two
           Eps15 homology domains (EH1 and EH2), a coiled-coil
           region and five SH3 domains (SH3A-E), while the long
           isoform, in addition, contains RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin homology (PH) and C2
           domains. The first SH3 domain (or SH3A) of ITSN1 has
           been shown to bind many proteins including Sos1,
           dynamin1/2, CIN85, c-Cbl, PI3K-C2, SHIP2, N-WASP, and
           CdGAP, among others. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 29.6 bits (66), Expect = 0.28
 Identities = 16/39 (41%), Positives = 23/39 (58%), Gaps = 2/39 (5%)

Query: 224 LKLEIGDIIKV--TKTNINGQWEGELNGKTGHFPFTHVE 260
           + ++ GDI+ V  ++T   G   GEL GKTG FP  + E
Sbjct: 16  ITIQPGDIVMVDESQTGEPGWLGGELKGKTGWFPANYAE 54


>gnl|CDD|212913 cd11980, SH3_VAV2_1, First Src homology 3 domain of VAV2 protein.
           VAV2 is widely expressed and functions as a guanine
           nucleotide exchange factor (GEF) for RhoA, RhoB and RhoG
           and also activates Rac1 and Cdc42. It is implicated in
           many cellular and physiological functions including
           blood pressure control, eye development, neurite
           outgrowth and branching, EGFR endocytosis and
           degradation, and cell cluster morphology, among others.
           It has been reported to associate with Nek3. VAV
           proteins contain several domains that enable their
           function: N-terminal calponin homology (CH), acidic,
           RhoGEF (also called Dbl-homologous or DH), Pleckstrin
           Homology (PH), C1 (zinc finger), SH2, and two SH3
           domains. The SH3 domain of VAV is involved in the
           localization of proteins to specific sites within the
           cell, by interacting with proline-rich sequences within
           target proteins. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 60

 Score = 29.5 bits (66), Expect = 0.29
 Identities = 14/43 (32%), Positives = 25/43 (58%), Gaps = 3/43 (6%)

Query: 221 KTALKLEIGDIIKVTKTNINGQ-WEGEL--NGKTGHFPFTHVE 260
           K  L  + GD+I++ + + +   WEG L    K+G+FP + V+
Sbjct: 17  KPVLTFQTGDVIELLRGDPDSPWWEGRLLQTKKSGYFPSSSVK 59


>gnl|CDD|212962 cd12029, SH3_DLG3, Src Homology 3 domain of Disks Large homolog 3. 
           DLG3, also called synapse-associated protein 102
           (SAP102), is a scaffolding protein that clusters at
           synapses and plays an important role in synaptic
           development and plasticity. Mutations in DLG3 cause
           midgestational embryonic lethality in mice and may be
           associated with nonsyndromic X-linked mental retardation
           in humans. It interacts with the NEDD4 (neural precursor
           cell-expressed developmentally downregulated 4) family
           of ubiquitin ligases and promotes apical tight junction
           formation. DLG3 is a member of the MAGUK
           (membrane-associated guanylate kinase) protein family,
           which is characterized by the presence of a core of
           three domains: PDZ, SH3, and guanylate kinase (GuK). The
           GuK domain in MAGUK proteins is enzymatically inactive;
           instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. DLG3 contains three PDZ domains. SH3 domains
           are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 67

 Score = 29.7 bits (66), Expect = 0.30
 Identities = 18/57 (31%), Positives = 28/57 (49%), Gaps = 10/57 (17%)

Query: 113 VIAKYDFDGNDPDDLP-----FKKNDILIVVSKDEEHWWTAQNI-----SGEVGSIP 159
           V A +D+D      LP     F   DIL V++  ++ WW A+ +     S ++G IP
Sbjct: 5   VRALFDYDRTRDSCLPSQGLSFSYGDILHVINASDDEWWQARLVTPHGESEQIGVIP 61


>gnl|CDD|212945 cd12012, SH3_RIM-BP_2, Second Src homology 3 domain of
           Rab3-interacting molecules (RIMs) binding proteins.
           RIMs binding proteins (RBPs, RIM-BPs) associate with
           calcium channels present in photoreceptors, neurons, and
           hair cells; they interact simultaneously with specific
           calcium channel subunits, and active zone proteins, RIM1
           and RIM2. RIMs are part of the matrix at the presynaptic
           active zone and are associated with synaptic vesicles
           through their interaction with the small GTPase Rab3.
           RIM-BPs play a role in regulating synaptic transmission
           by serving as adaptors and linking calcium channels with
           the synaptic vesicle release machinery. RIM-BPs contain
           three SH3 domains and two to three fibronectin III
           repeats. Invertebrates contain one, while vertebrates
           contain at least two RIM-BPs, RIM-BP1 and RIM-BP2.
           RIM-BP1 is also called peripheral-type benzodiazapine
           receptor associated protein 1 (PRAX-1). Mammals contain
           a third protein, RIM-BP3. RIM-BP1 and RIM-BP2 are
           predominantly expressed in the brain where they display
           overlapping but distinct expression patterns, while
           RIM-BP3 is almost exclusively expressed in the testis
           and is essential in spermiogenesis. The SH3 domains of
           RIM-BPs bind to the PxxP motifs of RIM1, RIM2, and
           L-type (alpha1D) and N-type (alpha1B) calcium channel
           subunits. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity. They play versatile and diverse roles
           in the cell including the regulation of enzymes,
           changing the subcellular localization of signaling
           pathway components, and mediating the formation of
           multiprotein complex assemblies.
          Length = 62

 Score = 29.6 bits (67), Expect = 0.31
 Identities = 15/46 (32%), Positives = 25/46 (54%), Gaps = 2/46 (4%)

Query: 216 PNAYDKTALKLEIGDIIKV-TKTNINGQWEGELNGKTGHFPFTHVE 260
           P+A ++  L  + G +IKV    + +G + GE+NG+ G  P   V 
Sbjct: 17  PDAAEEE-LPFKEGQLIKVYGDKDADGFYLGEINGRRGLVPCNMVS 61


>gnl|CDD|198175 cd09919, SH2_STAT_family, Src homology 2 (SH2) domain found in
          signal transducer and activator of transcription (STAT)
          family.  STAT proteins mediate the signaling of
          cytokines and a number of growth factors from the
          receptors of these extracellular signaling molecules to
          the cell nucleus.  STATs are specifically
          phosphorylated by receptor-associated Janus kinases,
          receptor tyrosine kinases, or cytoplasmic tyrosine
          kinases. The phosphorylated STAT molecules dimerize by
          reciprocal binding of their SH2 domains to the
          phosphotyrosine residues. These dimeric STATs
          translocate into the nucleus, bind to specific DNA
          sequences, and regulate the transcription of their
          target genes.  However there are a number of
          unphosphorylated STATs that travel between the
          cytoplasm and nucleus and some STATs that exist as
          dimers in unstimulated cells that can exert biological
          functions independent of being activated by a receptor.
          There are seven mammalian STAT family members which
          have been identified: STAT1, STAT2, STAT3, STAT4, STAT5
          (STAT5A and STAT5B), and STAT6. There are 6 conserved
          domains in STAT: N-terminal domain (NTD), coiled-coil
          domain (CCD), DNA-binding domain (DBD), alpha-helical
          linker domain (LD), SH2 domain, and transactivation
          domain (TAD).  NTD is involved in dimerization of
          unphosphorylated STATs monomers and for the
          tetramerization between STAT1, STAT3, STAT4 and STAT5
          on promoters with two or more tandem STAT binding
          sites.  It also plays a role in promoting interactions
          with transcriptional co-activators such as CREB binding
          protein (CBP)/p300, as well as being important for
          nuclear import and deactivation of STATs involving
          tyrosine de-phosphorylation. The CCD interacts with
          other proteins, such as IFN regulatory protein 9
          (IRF-9/p48) with STAT1 and c-JUN with STAT3 and is also
          thought to participate in the negative regulation of
          these proteins. Distinct genes are bound to STATs via
          their DBD domain. This domain is also involved in
          nuclear translocation of activated STAT1 and STAT3
          phosphorylated dimers upon cytokine stimulation.  LD
          links the DNA-binding and SH2 domains and is important
          for the transcriptional activation of STAT1 in response
          to IFN-gamma. It also plays a role in protein-protein
          interactions and has also been implicated in the
          constitutive nucleocytoplasmic shuttling of
          unphosphorylated STATs in resting cells.  The SH2
          domain is necessary for receptor association and
          tyrosine phosphodimer formation. Residues within this
          domain may be particularly important for some cellular
          functions mediated by the STATs as well as residues
          adjacent to this domain.  The TAD interacts with
          several proteins, namely minichromosome maintenance
          complex component 5 (MCM5), breast cancer 1 (BRCA1) and
          CBP/p300. TAD also contains a modulatory
          phosphorylation site that regulates STAT activity and
          is necessary for maximal transcription of a number of
          target genes. The conserved tyrosine residue present in
          the C-terminus is crucial for dimerization via
          interaction with the SH2 domain upon the interaction of
          the ligand with the receptor. STAT activation by
          tyrosine phosphorylation also determines nuclear import
          and retention, DNA binding to specific DNA elements in
          the promoters of responsive genes, and transcriptional
          activation of STAT dimers. In addition to the SH2
          domain there is a coiled-coil domain, a DNA binding
          domain, and a transactivation domain in the STAT
          proteins. In general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 115

 Score = 30.6 bits (70), Expect = 0.31
 Identities = 14/43 (32%), Positives = 23/43 (53%), Gaps = 5/43 (11%)

Query: 8  HDRNSWYF----GMMTRQEAQAILLSEKDNGAFLVRDSNTILG 46
          H    W      G ++++EA+ +L   K  G FL+R S++ LG
Sbjct: 12 HLLKLWQDGLIMGFISKEEAEDLLKK-KPPGTFLLRFSDSELG 53


>gnl|CDD|212922 cd11989, SH3_Intersectin1_2, Second Src homology 3 domain (or SH3B)
           of Intersectin-1.  Intersectin-1 (ITSN1) is an adaptor
           protein that functions in exo- and endocytosis, actin
           cytoskeletal reorganization, and signal transduction. It
           plays a role in clathrin-coated pit (CCP) formation. It
           binds to many proteins through its multidomain structure
           and facilitate the assembly of multimeric complexes.
           ITSN1 localizes in membranous organelles, CCPs, the
           Golgi complex, and may be involved in the cell membrane
           trafficking system. It exists in alternatively spliced
           short and long isoforms. The short isoform contains two
           Eps15 homology domains (EH1 and EH2), a coiled-coil
           region and five SH3 domains (SH3A-E), while the long
           isoform, in addition, contains RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin homology (PH) and C2
           domains. The second SH3 domain (or SH3B) of ITSN1 has
           been shown to bind WNK and CdGAP. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 29.3 bits (65), Expect = 0.32
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A Y +     + L F KND++ V+ + ++ WW  + + G+ G  P  YV+
Sbjct: 4   ALYPWRAKKDNHLNFNKNDVITVLEQ-QDMWWFGE-VQGQKGWFPKSYVK 51


>gnl|CDD|212997 cd12064, SH3_GRAF, Src Homology 3 domain of GTPase Regulator
           Associated with Focal adhesion kinase.  GRAF, also
           called Rho GTPase activating protein 26 (ARHGAP26),
           Oligophrenin-1-like (OPHN1L) or GRAF1, is a GAP with
           activity towards RhoA and Cdc42 and is only weakly
           active towards Rac1. It influences Rho-mediated
           cytoskeletal rearrangements and binds focal adhesion
           kinase (FAK), which is a critical component of integrin
           signaling. It is essential for the major
           clathrin-independent endocytic pathway mediated by
           pleiomorphic membranes. GRAF contains an N-terminal BAR
           domain, followed by a Pleckstrin homology (PH) domain, a
           Rho GAP domain, and a C-terminal SH3 domain. The SH3
           domain of GRAF binds PKNbeta, a target of the small
           GTPase Rho. SH3 domains bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 56

 Score = 29.3 bits (65), Expect = 0.33
 Identities = 13/22 (59%), Positives = 15/22 (68%)

Query: 241 GQWEGELNGKTGHFPFTHVEFI 262
           G  EG LNGKTG  P  +VEF+
Sbjct: 35  GWLEGTLNGKTGLIPENYVEFL 56


>gnl|CDD|213016 cd12140, SH3_Amphiphysin_I, Src Homology 3 domain of Amphiphysin I.
            Amphiphysins function primarily in endocytosis and
           other membrane remodeling events. They exist in several
           isoforms and mammals possess two amphiphysin proteins
           from distinct genes. Amphiphysin I proteins, enriched in
           the brain and nervous system, contain domains that bind
           clathrin, Adaptor Protein complex 2 (AP2), dynamin, and
           synaptojanin. They function in synaptic vesicle
           endocytosis. Human autoantibodies to amphiphysin I
           hinder GABAergic signaling and contribute to the
           pathogenesis of paraneoplastic stiff-person syndrome.
           Amphiphysins contain an N-terminal BAR domain with an
           additional N-terminal amphipathic helix (an N-BAR), a
           variable central domain, and a C-terminal SH3 domain.
           The SH3 domain of amphiphysins bind proline-rich motifs
           present in binding partners such as dynamin,
           synaptojanin, and nsP3. It also belongs to a subset of
           SH3 domains that bind ubiquitin in a site that overlaps
           with the peptide binding site. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 72

 Score = 29.9 bits (67), Expect = 0.33
 Identities = 13/39 (33%), Positives = 23/39 (58%), Gaps = 4/39 (10%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVV----SKDEEHWW 146
           KV   +DF+  + D+L  K+ DI++VV    + D++  W
Sbjct: 4   KVETLHDFEAANSDELELKRGDIVLVVPSETAADQDAGW 42


>gnl|CDD|213002 cd12069, SH3_ARHGAP27, Src Homology 3 domain of Rho
           GTPase-activating protein 27.  Rho GTPase-activating
           proteins (RhoGAPs or ARHGAPs) bind to Rho proteins and
           enhance the hydrolysis rates of bound GTP. ARHGAP27,
           also called CAMGAP1, shows GAP activity towards Rac1 and
           Cdc42. It binds the adaptor protein CIN85 and may play a
           role in clathrin-mediated endocytosis. It contains SH3,
           WW, Pleckstin homology (PH), and RhoGAP domains. SH3
           domains bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs;
           they play a role in the regulation of enzymes by
           intramolecular interactions, changing the subcellular
           localization of signal pathway components and mediate
           multiprotein complex assemblies.
          Length = 57

 Score = 29.4 bits (66), Expect = 0.33
 Identities = 15/55 (27%), Positives = 27/55 (49%), Gaps = 3/55 (5%)

Query: 113 VIAKYDFD--GNDPDDLPFKKNDILIVVSKDEEHWW-TAQNISGEVGSIPVPYVQ 164
           V+ ++ F+  G D   +  K N+  I++ +  EHWW   ++       IP  YV+
Sbjct: 2   VLVEHAFEYTGKDGRLVSIKPNERYILLRRTNEHWWHVRRDKGTRPFYIPAKYVK 56


>gnl|CDD|198247 cd10384, SH2_SOCS3, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7). In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 30.5 bits (69), Expect = 0.34
 Identities = 12/29 (41%), Positives = 19/29 (65%), Gaps = 1/29 (3%)

Query: 13 WYFGMMTRQEAQAILLSEKDNGAFLVRDS 41
          +Y+  ++ +EA   LLS +  G FL+RDS
Sbjct: 12 FYWSTVSGKEANL-LLSAEPAGTFLIRDS 39


>gnl|CDD|198202 cd10339, SH2_RIN_family, Src homology 2 (SH2) domain found in Ras
          and Rab interactor (RIN)-family.  The RIN (AKA Ras
          interaction/interference) family is composed of RIN1,
          RIN2 and RIN3. These proteins have multifunctional
          domains including SH2 and proline-rich (PR) domains in
          the N-terminal region, and RIN-family homology (RH),
          VPS9 and Ras-association (RA) domains in the C-terminal
          region. RIN proteins function as Rab5-GEFs, and RIN3
          specifically functions as a Rab31-GEF. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 101

 Score = 30.2 bits (68), Expect = 0.35
 Identities = 24/79 (30%), Positives = 30/79 (37%), Gaps = 13/79 (16%)

Query: 21 QEAQAILLSEKDNGAFLVRDSNTILGNYVLCVKENNK------VSHYIINKITNTEQQTC 74
              A +L  +  G FLVR SNT     VLC++            HYI            
Sbjct: 19 AAEAAHMLQTEPPGTFLVRKSNT-RQCQVLCMRLPEASGPAFVSEHYIKE-----SPGGV 72

Query: 75 YKIGDK-TFSDLPSLLAFY 92
             G +  F DL  L+AFY
Sbjct: 73 SLEGSELMFPDLFRLIAFY 91


>gnl|CDD|212718 cd11784, SH3_SH3RF2_3, Third Src Homology 3 domain of SH3 domain
           containing ring finger 2.  SH3RF2 is also called POSHER
           (POSH-eliminating RING protein) or HEPP1 (heart protein
           phosphatase 1-binding protein). It acts as an
           anti-apoptotic regulator of the JNK pathway by binding
           to and promoting the degradation of SH3RF1 (or POSH), a
           scaffold protein that is required for pro-apoptotic JNK
           activation. It may also play a role in cardiac functions
           together with protein phosphatase 1. SH3RF2 contains an
           N-terminal RING finger domain and three SH3 domains.
           This model represents the third SH3 domain, located in
           the middle, of SH3RF2. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 29.0 bits (65), Expect = 0.39
 Identities = 14/51 (27%), Positives = 28/51 (54%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQN-ISGEVGSIPVPYV 163
           +A + +  + P++L  +K + + V+ K +E W    + ++G VG  P  YV
Sbjct: 3   VALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLSLVTGRVGIFPSNYV 53


>gnl|CDD|212906 cd11973, SH3_ASEF, Src homology 3 domain of APC-Stimulated guanine
           nucleotide Exchange Factor.  ASEF, also called ARHGEF4,
           exists in an autoinhibited form and is activated upon
           binding of the tumor suppressor APC (adenomatous
           polyposis coli). GEFs activate small GTPases by
           exchanging bound GDP for free GTP. ASEF can activate
           Rac1 or Cdc42. Truncated ASEF, which is found in
           colorectal cancers, is constitutively active and has
           been shown to promote angiogenesis and cancer cell
           migration. ASEF contains a SH3 domain followed by RhoGEF
           (also called Dbl-homologous or DH) and Pleckstrin
           Homology (PH) domains. In its autoinhibited form, the
           SH3 domain of ASEF forms an extensive interface with the
           DH and PH domains, blocking the Rac binding site. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 73

 Score = 29.6 bits (66), Expect = 0.39
 Identities = 14/50 (28%), Positives = 24/50 (48%), Gaps = 1/50 (2%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           A +D    D  +L FK  D++ V+    + WW  + +  E G  P  +V+
Sbjct: 22  ALWDHVTMDDQELGFKAGDVIEVMDATNKEWWWGRVLDSE-GWFPASFVR 70


>gnl|CDD|212835 cd11902, SH3_Nck2_2, Second Src Homology 3 domain of Nck2 adaptor
           protein.  Nck2 (also called Nckbeta or Growth factor
           receptor-bound protein 4, Grb4) plays a crucial role in
           connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds neuronal signaling
           proteins such as ephrinB and Disabled-1 (Dab-1)
           exclusively. Nck adaptor proteins regulate actin
           cytoskeleton dynamics by linking proline-rich effector
           molecules to protein tyrosine kinases and phosphorylated
           signaling intermediates. They contain three SH3 domains
           and a C-terminal SH2 domain. They function downstream of
           the PDGFbeta receptor and are involved in Rho GTPase
           signaling and actin dynamics. Vertebrates contain two
           Nck adaptor proteins: Nck1 (also called Nckalpha) and
           Nck2, which show partly overlapping functions but also
           bind distinct targets. The second SH3 domain of Nck
           appears to prefer ligands containing the APxxPxR motif.
           SH3 domains are protein interaction domains that usually
           bind to proline-rich ligands with moderate affinity and
           selectivity, preferentially a PxxP motif. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 29.2 bits (65), Expect = 0.39
 Identities = 18/56 (32%), Positives = 26/56 (46%), Gaps = 4/56 (7%)

Query: 204 LPAFARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           +PAF +   V    A  +  L L  G  + V +   +G W G  NG+ G FP  +V
Sbjct: 1   IPAFVKFAYV----AEREDELSLVKGSRVTVMEKCSDGWWRGSYNGQIGWFPSNYV 52



 Score = 26.9 bits (59), Expect = 2.1
 Identities = 13/50 (26%), Positives = 23/50 (46%), Gaps = 1/50 (2%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
             K+ +     D+L   K   + V+ K  + WW   + +G++G  P  YV
Sbjct: 4   FVKFAYVAEREDELSLVKGSRVTVMEKCSDGWWRG-SYNGQIGWFPSNYV 52


>gnl|CDD|212722 cd11788, SH3_RasGAP, Src Homology 3 domain of Ras GTPase-Activating
           Protein 1.  RasGAP, also called Ras p21 protein
           activator, RASA1, or p120RasGAP, is part of the GAP1
           family of GTPase-activating proteins. It is a 120kD
           cytosolic protein containing an SH3 domain flanked by
           two SH2 domains at the N-terminal end, a pleckstrin
           homology (PH) domain, a calcium dependent phospholipid
           binding domain (CaLB/C2), and a C-terminal catalytic GAP
           domain. It stimulates the GTPase activity of normal RAS
           p21. It acts as a positive effector of Ras in tumor
           cells. It also functions as a regulator downstream of
           tyrosine receptors such as those of PDGF, EGF, ephrin,
           and insulin, among others. The SH3 domain of RasGAP is
           unable to bind proline-rich sequences but have been
           shown to interact with protein partners such as the G3BP
           protein, Aurora kinases, and the Calpain small subunit
           1. The RasGAP SH3 domain is necessary for the downstream
           signaling of Ras and it also influences Rho-mediated
           cytoskeletal reorganization. SH3 domains are protein
           interaction domains that typically bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 59

 Score = 28.9 bits (65), Expect = 0.44
 Identities = 14/39 (35%), Positives = 22/39 (56%), Gaps = 1/39 (2%)

Query: 123 DPDDLPFKKNDILIVVSKDEEHW-WTAQNISGEVGSIPV 160
           D D+L F+K DI +V ++ E+ W W     +GE G +  
Sbjct: 15  DTDELSFQKGDIFVVHNELEDGWLWVTSLRTGESGLVFR 53


>gnl|CDD|212944 cd12011, SH3_SLAP2, Src homology 3 domain of Src-Like Adaptor
           Protein 2.  SLAP2 plays a role in c-Cbl-dependent
           regulation of CSF1R, a tyrosine kinase important for
           myeloid cell growth and differentiation. It has been
           shown to interact with CSF1R, c-Cbl, LAT, CD247, and
           Zap70. SLAPs are adaptor proteins with limited
           similarity to Src family tyrosine kinases. They contain
           an N-terminal SH3 domain followed by an SH2 domain, and
           a unique C-terminal sequence. They function in
           regulating the signaling, ubiquitination, and
           trafficking of T-cell receptor (TCR) and B-cell receptor
           (BCR) components. The SH3 domain of SLAP forms a complex
           with v-Abl. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 28.9 bits (65), Expect = 0.45
 Identities = 14/52 (26%), Positives = 26/52 (50%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +A  +F    P +L  +  + L ++S+D + W  +  ++G    IP  YV K
Sbjct: 3   VALCNFPSGGPTELSIRMGEQLTILSEDGDWWKVSSAVTGRECYIPSNYVAK 54


>gnl|CDD|212950 cd12017, SH3_Tks_3, Third Src homology 3 domain of Tyrosine kinase
           substrate (Tks) proteins.  Tks proteins are Src
           substrates and scaffolding proteins that play important
           roles in the formation of podosomes and invadopodia, the
           dynamic actin-rich structures that are related to cell
           migration and cancer cell invasion. Vertebrates contain
           two Tks proteins, Tks4 (Tyr kinase substrate with four
           SH3 domains) and Tks5 (Tyr kinase substrate with five
           SH3 domains), which display partially overlapping but
           non-redundant functions. Both associate with the ADAMs
           family of transmembrane metalloproteases, which function
           as sheddases and mediators of cell and matrix
           interactions. Tks5 interacts with N-WASP and Nck, while
           Tks4 is essential for the localization of MT1-MMP
           (membrane-type 1 matrix metalloproteinase) to
           invadopodia. Tks proteins contain an N-terminal Phox
           homology (PX) domain and four or five SH3 domains. This
           model characterizes the third SH3 domain of Tks
           proteins. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 28.6 bits (64), Expect = 0.47
 Identities = 14/48 (29%), Positives = 24/48 (50%), Gaps = 1/48 (2%)

Query: 118 DFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           +F     D + F+K   + V+ K+   WW  + I G+ G  P  Y++K
Sbjct: 7   EFQATIQDGISFQKGQKVEVIDKNPSGWWYVK-IDGKEGWAPSSYIEK 53


>gnl|CDD|212811 cd11878, SH3_Bem1p_1, First Src Homology 3 domain of Bud emergence
           protein 1 and similar domains.  Members of this
           subfamily bear similarity to Saccharomyces cerevisiae
           Bem1p, containing two Src Homology 3 (SH3) domains at
           the N-terminus, a central PX domain, and a C-terminal
           PB1 domain. Bem1p is a scaffolding protein that is
           critical for proper Cdc42p activation during bud
           formation in yeast. During budding and mating, Bem1p
           migrates to the plasma membrane where it can serve as an
           adaptor for Cdc42p and some other proteins. Bem1p also
           functions as an effector of the G1 cyclin Cln3p and the
           cyclin-dependent kinase Cdc28p in promoting vacuolar
           fusion. SH3 domains bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially to
           PxxP motifs; they play a role in the regulation of
           enzymes by intramolecular interactions, changing the
           subcellular localization of signal pathway components
           and mediate multiprotein complex assemblies.
          Length = 54

 Score = 28.4 bits (64), Expect = 0.51
 Identities = 19/53 (35%), Positives = 29/53 (54%), Gaps = 3/53 (5%)

Query: 113 VI-AKYDFDGNDPDDLPFKKNDILIVVSK-DEEHWWTAQN-ISGEVGSIPVPY 162
           VI A YD+    P +L F K D   V+ + D+  W+ A N ++G+ G +P  Y
Sbjct: 1   VIRALYDYRAQTPGELSFSKGDFFHVIGEEDQGEWYEATNPVTGKRGLVPKSY 53


>gnl|CDD|212963 cd12030, SH3_DLG4, Src Homology 3 domain of Disks Large homolog 4. 
           DLG4, also called postsynaptic density-95 (PSD95) or
           synapse-associated protein 90 (SAP90), is a scaffolding
           protein that clusters at synapses and plays an important
           role in synaptic development and plasticity. It is
           responsible for the membrane clustering and retention of
           many transporters and receptors such as potassium
           channels and PMCA4b, a P-type ion transport ATPase,
           among others. DLG4 is a member of the MAGUK
           (membrane-associated guanylate kinase) protein family,
           which is characterized by the presence of a core of
           three domains: PDZ, SH3, and guanylate kinase (GuK). The
           GuK domain in MAGUK proteins is enzymatically inactive;
           instead, the domain mediates protein-protein
           interactions and associates intramolecularly with the
           SH3 domain. DLG4 contains three PDZ domains. The SH3
           domain of DLG4 binds and clusters the kainate subgroup
           of glutamate receptors via two proline-rich sequences in
           their C-terminal tail. It also binds AKAP79/150
           (A-kinase anchoring protein). SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 66

 Score = 28.7 bits (64), Expect = 0.54
 Identities = 13/38 (34%), Positives = 20/38 (52%), Gaps = 5/38 (13%)

Query: 127 LPFKKNDILIVVSKDEEHWWTAQNISG-----EVGSIP 159
           L F+  D+L V+   +E WW A+ +       E+G IP
Sbjct: 23  LSFRFGDVLHVIDAGDEEWWQARRVHSDSETEEIGFIP 60


>gnl|CDD|212890 cd11957, SH3_RUSC2, Src homology 3 domain of RUN and SH3
           domain-containing protein 2.  RUSC2, also called Iporin
           or Interacting protein of Rab1, is expressed
           ubiquitously with highest amounts in the brain and
           testis. It interacts with the small GTPase Rab1 and the
           Golgi matrix protein GM130, and may function in linking
           GTPases to certain intracellular signaling pathways.
           RUSC proteins are adaptor proteins consisting of RUN,
           leucine zipper, and SH3 domains. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 52

 Score = 28.3 bits (63), Expect = 0.56
 Identities = 14/41 (34%), Positives = 23/41 (56%), Gaps = 1/41 (2%)

Query: 123 DPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           +P  L F K DIL V+S+ +  W    ++  + G +P+ YV
Sbjct: 12  EPGQLSFNKGDILQVLSRADGDWLRC-SLGPDSGLVPIAYV 51


>gnl|CDD|212828 cd11895, SH3_FCHSD1_2, Second Src Homology 3 domain of FCH and
           double SH3 domains protein 1.  FCHSD1 has a domain
           structure consisting of an N-terminal F-BAR (FES-CIP4
           Homology and Bin/Amphiphysin/Rvs), two SH3, and
           C-terminal proline-rich domains. It has only been
           characterized in silico and its function is unknown. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 58

 Score = 28.4 bits (63), Expect = 0.61
 Identities = 12/55 (21%), Positives = 27/55 (49%), Gaps = 5/55 (9%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEH----WWTAQNISGEVGSIPVPYVQK 165
           A Y + G  P++L F +  ++ ++ + ++     +W  +   G VG  P   V++
Sbjct: 4   ALYSYTGQSPEELSFPEGALIRLLPRAQDGVDDGFWRGE-FGGRVGVFPSLLVEE 57


>gnl|CDD|212831 cd11898, SH3_SNX9, Src Homology 3 domain of Sorting nexin 9.
           Sorting nexin 9 (SNX9), also known as SH3PX1, is a
           cytosolic protein that interacts with proteins
           associated with clathrin-coated pits such as
           Cdc-42-associated tyrosine kinase 2 (ACK2). It binds
           class I polyproline sequences found in dynamin 1/2 and
           the WASP/N-WASP actin regulators. SNX9 is localized to
           plasma membrane endocytic sites and acts primarily in
           clathrin-mediated endocytosis. Its array of interacting
           partners suggests that SNX9 functions at the interface
           between endocytosis and actin cytoskeletal organization.
           SNXs are Phox homology (PX) domain containing proteins
           that are involved in regulating membrane traffic and
           protein sorting in the endosomal system. SNX9 also
           contains BAR and SH3 domains. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 28.3 bits (63), Expect = 0.64
 Identities = 18/52 (34%), Positives = 28/52 (53%), Gaps = 6/52 (11%)

Query: 117 YDFD---GNDPDDLPFKKNDILIVVSKD-EEHWWTAQNISGEVGSIPVPYVQ 164
           YDF    GN+  +L  K+ +I+ V + +    W  A+N  GE G +P  YV+
Sbjct: 6   YDFAAEPGNN--ELTVKEGEIITVTNPNVGGGWIEAKNSQGERGLVPTDYVE 55



 Score = 28.3 bits (63), Expect = 0.79
 Identities = 18/52 (34%), Positives = 27/52 (51%), Gaps = 8/52 (15%)

Query: 219 YDKTA------LKLEIGDIIKVTKTNINGQW-EGELN-GKTGHFPFTHVEFI 262
           YD  A      L ++ G+II VT  N+ G W E + + G+ G  P  +VE +
Sbjct: 6   YDFAAEPGNNELTVKEGEIITVTNPNVGGGWIEAKNSQGERGLVPTDYVEIV 57


>gnl|CDD|212998 cd12065, SH3_GRAF2, Src Homology 3 domain of GTPase Regulator
           Associated with Focal adhesion kinase 2.  GRAF2, also
           called Rho GTPase activating protein 10 (ARHGAP10) or
           PS-GAP, is a GAP with activity towards Cdc42 and RhoA.
           It regulates caspase-activated p21-activated protein
           kinase-2 (PAK-2p34). GRAF2 interacts with PAK-2p34,
           leading to its stabilization and decrease of cell death.
           It is highly expressed in skeletal muscle, and is
           involved in alpha-catenin recruitment at cell-cell
           junctions. GRAF2 contains an N-terminal BAR domain,
           followed by a Pleckstrin homology (PH) domain, a Rho GAP
           domain, and a C-terminal SH3 domain. The SH3 domain of
           GRAF binds PKNbeta, a target of the small GTPase Rho.
           SH3 domains bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs;
           they play a role in the regulation of enzymes by
           intramolecular interactions, changing the subcellular
           localization of signal pathway components and mediate
           multiprotein complex assemblies.
          Length = 54

 Score = 28.4 bits (63), Expect = 0.66
 Identities = 20/54 (37%), Positives = 26/54 (48%), Gaps = 1/54 (1%)

Query: 209 RVKQVRVPNAYDKTALKLEIGDIIK-VTKTNINGQWEGELNGKTGHFPFTHVEF 261
           + K V    A   + L  E+G I + VT +   G  EG LNGK G  P  +VE 
Sbjct: 1   KAKAVYPCEAEHSSELSFEVGAIFEDVTLSREPGWLEGTLNGKRGLIPENYVEI 54


>gnl|CDD|212887 cd11954, SH3_ASPP1, Src Homology 3 domain of Apoptosis Stimulating
           of p53 protein 1.  ASPP1, like ASPP2, activates the
           apoptotic function of the p53 family of tumor
           suppressors (p53, p63, and p73). In addition, it
           functions in the cytoplasm to regulate the nuclear
           localization of the transcriptional cofactors YAP and
           TAZ by inihibiting their phosphorylation; YAP and TAZ
           are important regulators of cell expansion,
           differentiation, migration, and invasion. ASPP1 is
           downregulated in breast tumors expressing wild-type p53.
           It contains a proline-rich region, four ankyrin (ANK)
           repeats, and an SH3 domain at its C-terminal half. The
           SH3 domain and the ANK repeats of ASPP1 contribute to
           the p53 binding site; they bind to the DNA binding
           domain of p53. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 28.4 bits (63), Expect = 0.69
 Identities = 15/42 (35%), Positives = 24/42 (57%), Gaps = 4/42 (9%)

Query: 113 VIAKYDFDGNDPDDLPFKKND-ILIVVSKDE---EHWWTAQN 150
           V A +D++  + D+L F++ D I I+  KD+   E WW   N
Sbjct: 3   VYALWDYEAQNADELSFQEGDAITILRRKDDSETEWWWARLN 44


>gnl|CDD|198249 cd10386, SH2_SOCS5, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) family.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7).  In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 81

 Score = 28.9 bits (64), Expect = 0.70
 Identities = 16/28 (57%), Positives = 20/28 (71%), Gaps = 1/28 (3%)

Query: 14 YFGMMTRQEAQAILLSEKDNGAFLVRDS 41
          Y+G+M R EA+A LL  K  G FL+RDS
Sbjct: 3  YWGVMDRYEAEA-LLEGKPEGTFLLRDS 29


>gnl|CDD|212834 cd11901, SH3_Nck1_2, Second Src Homology 3 domain of Nck1 adaptor
           protein.  Nck1 (also called Nckalpha) plays a crucial
           role in connecting signaling pathways of tyrosine kinase
           receptors and important effectors in actin dynamics and
           cytoskeletal remodeling. It binds and activates RasGAP,
           resulting in the downregulation of Ras. It is also
           involved in the signaling of endothilin-mediated
           inhibition of cell migration. Nck adaptor proteins
           regulate actin cytoskeleton dynamics by linking
           proline-rich effector molecules to protein tyrosine
           kinases and phosphorylated signaling intermediates. They
           contain three SH3 domains and a C-terminal SH2 domain.
           They function downstream of the PDGFbeta receptor and
           are involved in Rho GTPase signaling and actin dynamics.
           Vertebrates contain two Nck adaptor proteins: Nck1 (also
           called Nckalpha) and Nck2, which show partly overlapping
           functions but also bind distinct targets. The second SH3
           domain of Nck appears to prefer ligands containing the
           APxxPxR motif. SH3 domains are protein interaction
           domains that usually bind to proline-rich ligands with
           moderate affinity and selectivity, preferentially a PxxP
           motif. They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 55

 Score = 28.1 bits (62), Expect = 0.80
 Identities = 15/48 (31%), Positives = 25/48 (52%), Gaps = 1/48 (2%)

Query: 116 KYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYV 163
           K+++     D+L   K   +IV+ K  + WW   + +G+VG  P  YV
Sbjct: 7   KFNYTAEREDELSLVKGTKVIVMEKCSDGWWRG-SYNGQVGWFPSNYV 53



 Score = 26.5 bits (58), Expect = 3.0
 Identities = 17/56 (30%), Positives = 25/56 (44%), Gaps = 4/56 (7%)

Query: 204 LPAFARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHV 259
           LPA+ +        A  +  L L  G  + V +   +G W G  NG+ G FP  +V
Sbjct: 2   LPAYVKFNYT----AEREDELSLVKGTKVIVMEKCSDGWWRGSYNGQVGWFPSNYV 53


>gnl|CDD|212908 cd11975, SH3_ARHGEF9, Src homology 3 domain of the Rho guanine
           nucleotide exchange factor ARHGEF9.  ARHGEF9, also
           called PEM2 or collybistin, selectively activates Cdc42
           by exchanging bound GDP for free GTP. It is highly
           expressed in the brain and it interacts with gephyrin, a
           postsynaptic protein associated with GABA and glycine
           receptors. Mutations in the ARHGEF9 gene cause X-linked
           mental retardation with associated features like
           seizures, hyper-anxiety, aggressive behavior, and
           sensory hyperarousal. ARHGEF9 contains a SH3 domain
           followed by RhoGEF (also called Dbl-homologous or DH)
           and Pleckstrin Homology (PH) domains. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 62

 Score = 28.1 bits (62), Expect = 0.82
 Identities = 13/39 (33%), Positives = 20/39 (51%), Gaps = 1/39 (2%)

Query: 126 DLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +L FK  D++ V+    + WW  Q I  E G  P  +V+
Sbjct: 20  ELAFKAGDVIKVLDASNKDWWWGQ-IDDEEGWFPASFVR 57



 Score = 27.4 bits (60), Expect = 1.6
 Identities = 12/38 (31%), Positives = 20/38 (52%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKTGHFPFTHVEF 261
           L  + GD+IKV   +    W G+++ + G FP + V  
Sbjct: 21  LAFKAGDVIKVLDASNKDWWWGQIDDEEGWFPASFVRL 58


>gnl|CDD|198245 cd10382, SH2_SOCS1, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7).  In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 98

 Score = 29.3 bits (66), Expect = 0.82
 Identities = 14/33 (42%), Positives = 21/33 (63%), Gaps = 1/33 (3%)

Query: 9  DRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDS 41
          D + +Y+G ++ +EA A L  E   G FL+RDS
Sbjct: 8  DASGFYWGPLSVEEAHAKLKREPV-GTFLIRDS 39


>gnl|CDD|198219 cd10356, SH2_ShkA_ShkC, Src homology 2 (SH2) domain found in SH2
          domain-bearing protein kinases A and C (ShkA and ShkC).
           SH2-bearing genes cloned from Dictyostelium include
          two transcription factors, STATa and STATc, and a
          signaling factor, SHK1 (shkA). A database search of the
          Dictyostelium discoideum genome revealed two additional
          putative STAT sequences, dd-STATb and dd-STATd, and
          four additional putative SHK genes, dd-SHK2 (shkB),
          dd-SHK3 (shkC), dd-SHK4 (shkD), and dd-SHK5 (shkE).
          This model contains members of shkA and shkC.  All of
          the SHK members are most closely related to the protein
          kinases found in plants.  However these kinases in
          plants are not conjugated to any SH2 or SH2-like
          sequences. Alignment data indicates that the SHK SH2
          domains carry some features of the STAT SH2 domains in
          Dictyostelium. When STATc's linker domain was used for
          a BLAST search, the sequence between the protein kinase
          domain and the SH2 domain (the linker) of SHK was
          recovered, suggesting a close relationship among these
          molecules within this region. SHK's linker domain is
          predicted to contain an alpha-helix which is indeed
          homologous to that of STAT. Based on the phylogenetic
          alignment, SH2 domains can be grouped into two
          categories, STAT-type and Src-type. SHK family members
          are in between, but are closer to the STAT-type which
          indicates a close relationship between SHK and STAT
          families in their SH2 domains and further supports the
          notion that SHKs linker-SH2 domain evolved from STAT or
          STATL (STAT-like Linker-SH2) domain found in plants. In
          SHK, STAT, and SPT6, the linker-SH2 domains all reside
          exclusively in the C-terminal regions. In general SH2
          domains are involved in signal transduction. They
          typically bind pTyr-containing ligands via two surface
          pockets, a pTyr and hydrophobic binding pocket,
          allowing proteins with SH2 domains to localize to
          tyrosine phosphorylated sites.
          Length = 113

 Score = 29.5 bits (66), Expect = 0.85
 Identities = 18/55 (32%), Positives = 31/55 (56%), Gaps = 2/55 (3%)

Query: 12 SWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLC-VKENNKVSHYIINK 65
          +W+ G ++  E++   L+ K  G FLVR S +  G Y +  V +N  +SH  I++
Sbjct: 11 AWFHGDISTSESEN-RLNGKPEGTFLVRFSTSEPGAYTISKVSKNGGISHQRIHR 64


>gnl|CDD|212916 cd11983, SH3_Shank2, Src homology 3 domain of SH3 and multiple
           ankyrin repeat domains protein 2.  Shank2, also called
           ProSAP1 (Proline-rich synapse-associated protein 1) or
           CortBP1 (Cortactin-binding protein 1), is found in
           neurons, glia, endocrine cells, liver, and kidney. It
           plays a role in regulating dendritic spine volume and
           branching and postsynaptic clustering. Mutations in the
           Shank2 gene are associated with autism spectrum disorder
           and mental retardation. Shank proteins carry scaffolding
           functions through multiple sites of protein-protein
           interaction in its domain architecture, including
           ankyrin (ANK) repeats, a long proline rich region, as
           well as SH3, PDZ, and SAM domains. The SH3 domain of
           Shank binds GRIP, a scaffold protein that binds AMPA
           receptors and Eph receptors/ligands. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 28.0 bits (62), Expect = 0.91
 Identities = 13/30 (43%), Positives = 14/30 (46%)

Query: 226 LEIGDIIKVTKTNINGQWEGELNGKTGHFP 255
           L  GD +KV      G WEG   G  G FP
Sbjct: 19  LHKGDRVKVLSIGEGGFWEGSARGHVGWFP 48


>gnl|CDD|213004 cd12071, SH3_FBP17, Src Homology 3 domain of Formin Binding Protein
           17.  Formin Binding Protein 17 (FBP17), also called
           FormiN Binding Protein 1 (FNBP1), is involved in
           dynamin-mediated endocytosis. It is recruited to
           clathrin-coated pits late in the endocytosis process and
           may play a role in the invagination and scission steps.
           FBP17 binds in vivo to tankyrase, a protein involved in
           telomere maintenance and mitogen activated protein
           kinase (MAPK) signaling. It contains an N-terminal F-BAR
           (FES-CIP4 Homology and Bin/Amphiphysin/Rvs) domain, a
           Cdc42-binding HR1 domain, and a C-terminal SH3 domain.
           The SH3 domain of the related protein, CIP4, associates
           with Gapex-5, a Rab31 GEF. SH3 domains are protein
           interaction domains that bind to proline-rich ligands
           with moderate affinity and selectivity, preferentially
           to PxxP motifs. They play versatile and diverse roles in
           the cell including the regulation of enzymes, changing
           the subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 57

 Score = 28.0 bits (62), Expect = 0.97
 Identities = 14/53 (26%), Positives = 27/53 (50%), Gaps = 1/53 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWT-AQNISGEVGSIPVPYVQKY 166
           A Y F+G +   +   + ++L V+ +D+   WT  +    E G +P  Y++ Y
Sbjct: 5   ALYPFEGQNEGTISVAEGEMLYVIEEDKGDGWTRIRRNEDEEGYVPTSYIEVY 57


>gnl|CDD|220394 pfam09773, Meckelin, Meckelin (Transmembrane protein 67).  Members
           of this family are thought to be related to the ciliary
           basal body. Defects result in Meckel syndrome type 3, an
           autosomal recessive disorder characterized by a
           combination of renal cysts and variably associated
           features including developmental anomalies of the
           central nervous system (typically encephalocele),
           hepatic ductal dysplasia and cysts, and polydactyly.
           Joubert syndrome type 6 is also a manifestation of
           certain mutations; it is an autosomal recessive
           congenital malformation of the cerebellar vermis and
           brainstem with abnormalities of axonal decussation
           (crossing in the brain) affecting the corticospinal
           tract and superior cerebellar peduncles. Individuals
           with Joubert syndrome have motor and behavioral
           abnormalities, including an inability to walk due to
           severe clumsiness and 'mirror' movements, and cognitive
           and behavioural disturbances.
          Length = 847

 Score = 30.5 bits (69), Expect = 1.1
 Identities = 22/89 (24%), Positives = 35/89 (39%), Gaps = 16/89 (17%)

Query: 45  LGNYVLCVKENNKVSHYIINKITNT--EQQTCYKIGDKTFSDLPSLLAFYKVH------Y 96
           L N  LCV     ++     ++  T    +  Y    +    LP L  FY  +       
Sbjct: 86  LAN--LCVLMMFSLTSTPC-RLFLTVFSSKAKYAHSGQWRRSLPWL--FYGRNTATASIV 140

Query: 97  LDTSPL-IKPATK--TIEKVIAKYDFDGN 122
           L T PL  + + +   ++ V+A YD  GN
Sbjct: 141 LSTLPLPTRLSFRGKNLKLVVAVYDLRGN 169


>gnl|CDD|198248 cd10385, SH2_SOCS4, Src homology 2 (SH2) domain found in
          suppressor of cytokine signaling (SOCS) proteins.  SH2
          domain found in SOCS proteins. SOCS was first
          recognized as a group of cytokine-inducible SH2 (CIS)
          domain proteins comprising eight family members in
          human (CIS and SOCS1-SOCS7). In addition to the SH2
          domain, SOCS proteins have a variable N-terminal domain
          and a conserved SOCS box in the C-terminal domain. SOCS
          proteins bind to a substrate via their SH2 domain. The
          prototypical members, CIS and SOCS1-SOCS3, have been
          shown to regulate growth hormone signaling in vitro and
          in a classic negative feedback response compete for
          binding at phosphotyrosine sites in JAK kinase and
          receptor pathways to displace effector proteins and
          target bound receptors for proteasomal degradation.
          Loss of SOCS activity results in excessive cytokine
          signaling associated with a variety of hematopoietic,
          autoimmune, and inflammatory diseases and certain
          cancers. Members (SOCS4-SOCS7) were identified by their
          conserved SOCS box, an adapter motif of 3 helices that
          associates substrate binding domains, such as the SOCS
          SH2 domain, ankryin, and WD40 with ubiquitin ligase
          components. These show limited cytokine induction. In
          general SH2 domains are involved in signal
          transduction. They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 101

 Score = 28.1 bits (62), Expect = 1.7
 Identities = 15/31 (48%), Positives = 20/31 (64%), Gaps = 1/31 (3%)

Query: 11 NSWYFGMMTRQEAQAILLSEKDNGAFLVRDS 41
          N  Y+G+M +  A+A LL  K  G FL+RDS
Sbjct: 10 NPCYWGVMDKYAAEA-LLEGKPEGTFLLRDS 39


>gnl|CDD|212710 cd11776, SH3_PI3K_p85, Src Homology 3 domain of the p85 regulatory
           subunit of Class IA Phosphatidylinositol 3-kinases.
           Class I PI3Ks convert PtdIns(4,5)P2 to the critical
           second messenger PtdIns(3,4,5)P3. They are heterodimers
           and exist in multiple isoforms consisting of one
           catalytic subunit (out of four isoforms) and one of
           several regulatory subunits. Class IA PI3Ks associate
           with the p85 regulatory subunit family, which contains
           SH3, RhoGAP, and SH2 domains. The p85 subunits recruit
           the PI3K p110 catalytic subunit to the membrane, where
           p110 phosphorylates inositol lipids. Vertebrates harbor
           two p85 isoforms, called alpha and beta. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 72

 Score = 27.5 bits (61), Expect = 1.9
 Identities = 18/68 (26%), Positives = 27/68 (39%), Gaps = 16/68 (23%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIV---------------VSKDEEHWWTAQN-ISGEVGSI 158
           A YD++    +D+  K  D+L+V                    E W   +N  +GE G  
Sbjct: 5   ALYDYEKERDEDIILKTGDVLVVENPELLALGVPDGKETVPKPEGWLEGKNERTGERGDF 64

Query: 159 PVPYVQKY 166
           P  YV+ Y
Sbjct: 65  PGTYVEFY 72


>gnl|CDD|212859 cd11926, SH3_SH3RF1_3, Third Src Homology 3 domain of SH3 domain
           containing ring finger 1, an E3 ubiquitin-protein
           ligase.  SH3RF1 is also called POSH (Plenty of SH3s) or
           SH3MD2 (SH3 multiple domains protein 2). It is a
           scaffold protein that acts as an E3 ubiquitin-protein
           ligase. It plays a role in calcium homeostasis through
           the control of the ubiquitin domain protein Herp. It may
           also have a role in regulating death receptor mediated
           and JNK mediated apoptosis. SH3RF1 also enhances the
           ubiquitination of ROMK1 potassium channel resulting in
           its increased endocytosis. It contains an N-terminal
           RING finger domain and four SH3 domains. This model
           represents the third SH3 domain, located in the middle,
           of SH3RF1. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 26.9 bits (59), Expect = 2.1
 Identities = 11/51 (21%), Positives = 27/51 (52%), Gaps = 1/51 (1%)

Query: 114 IAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYV 163
           +A Y +     D+L  +K ++ +V  + ++ W+   ++ + ++G  P  YV
Sbjct: 3   VAIYPYTPRKEDELELRKGEMFLVFERCQDGWFKGTSMHTSKIGVFPGNYV 53


>gnl|CDD|212914 cd11981, SH3_VAV3_1, First Src homology 3 domain of VAV3 protein.
           VAV3 is ubiquitously expressed and functions as a
           phosphorylation-dependent guanine nucleotide exchange
           factor (GEF) for RhoA, RhoG, and Rac1. It has been
           implicated to function in the hematopoietic, bone,
           cerebellar, and cardiovascular systems. VAV3 is
           essential in axon guidance in neurons that control blood
           pressure and respiration. It is overexpressed in
           prostate cancer cells and it plays a role in regulating
           androgen receptor transcriptional activity. VAV proteins
           contain several domains that enable their function:
           N-terminal calponin homology (CH), acidic, RhoGEF (also
           called Dbl-homologous or DH), Pleckstrin Homology (PH),
           C1 (zinc finger), SH2, and two SH3 domains. The SH3
           domain of VAV is involved in the localization of
           proteins to specific sites within the cell, by
           interacting with proline-rich sequences within target
           proteins. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 62

 Score = 27.1 bits (60), Expect = 2.2
 Identities = 13/43 (30%), Positives = 20/43 (46%), Gaps = 3/43 (6%)

Query: 216 PNAYDKTALKLEIGDIIKVTKTNINGQ-WEGEL--NGKTGHFP 255
           P  +    L  +IGD I+V   + +   W+G     G+ G FP
Sbjct: 14  PQLHGGPPLNAQIGDTIEVLYADPHSLFWQGRNLTTGELGFFP 56


>gnl|CDD|212912 cd11979, SH3_VAV1_1, First Src homology 3 domain of VAV1 protein.
           VAV1 is expressed predominantly in the hematopoietic
           system and it plays an important role in the development
           and activation of B and T cells. It is activated by
           tyrosine phosphorylation to function as a guanine
           nucleotide exchange factor (GEF) for Rho GTPases
           following cell surface receptor activation, triggering
           various effects such as cytoskeletal reorganization,
           transcription regulation, cell cycle progression, and
           calcium mobilization. It also serves as a scaffold
           protein and has been shown to interact with Ku70, Socs1,
           Janus kinase 2, SIAH2, S100B, Abl gene, ZAP-70, SLP76,
           and Syk, among others. VAV proteins contain several
           domains that enable their function: N-terminal calponin
           homology (CH), acidic, RhoGEF (also called
           Dbl-homologous or DH), Pleckstrin Homology (PH), C1
           (zinc finger), SH2, and two SH3 domains. The first SH3
           domain of Vav1 has been shown to bind the adaptor
           protein Grb2. SH3 domains are protein interaction
           domains that bind to proline-rich ligands with moderate
           affinity and selectivity, preferentially to PxxP motifs.
           They play versatile and diverse roles in the cell
           including the regulation of enzymes, changing the
           subcellular localization of signaling pathway
           components, and mediating the formation of multiprotein
           complex assemblies.
          Length = 63

 Score = 27.3 bits (60), Expect = 2.2
 Identities = 13/42 (30%), Positives = 22/42 (52%), Gaps = 2/42 (4%)

Query: 127 LPFKKNDIL-IVVSKDEEHWWTAQNIS-GEVGSIPVPYVQKY 166
           L     DI+ +  ++ E++WW  +N S  E+G  P   V+ Y
Sbjct: 22  LRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVKPY 63



 Score = 26.9 bits (59), Expect = 2.4
 Identities = 14/40 (35%), Positives = 19/40 (47%), Gaps = 3/40 (7%)

Query: 224 LKLEIGDIIKVTKTNINGQWEGELNGKT---GHFPFTHVE 260
           L+L  GDI+++TK      W    N  T   G FP   V+
Sbjct: 22  LRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRVK 61


>gnl|CDD|130916 TIGR01857, FGAM-synthase, phosphoribosylformylglycinamidine
           synthase, clade II.  This model represents a
           single-molecule form of
           phosphoribosylformylglycinamidine synthase, also called
           FGAM synthase, an enzyme of purine de novo biosynthesis.
           This model represents a second clade of these enzymes
           found in Clostridia, Bifidobacteria and Streptococcus
           species. This enzyme performs the fourth step in IMP
           biosynthesis (the precursor of all purines) from PRPP
           [Purines, pyrimidines, nucleosides, and nucleotides,
           Purine ribonucleotide biosynthesis].
          Length = 1239

 Score = 29.4 bits (66), Expect = 2.5
 Identities = 18/66 (27%), Positives = 31/66 (46%), Gaps = 3/66 (4%)

Query: 23  AQAI-LLSEKDNGAFLVRDSNTILGNYVLCVKENNKVSHYIINKITNTEQQTCYKIGDKT 81
            + I LLSE ++    V  +   + N  L  +E NK+ +Y IN + + E+        + 
Sbjct: 97  QECILLLSESEDVT--VNTAKLYILNGDLDDEELNKIKNYYINPVDSREKDLTTGKALEE 154

Query: 82  FSDLPS 87
           FS+ P 
Sbjct: 155 FSESPK 160


>gnl|CDD|212875 cd11942, SH3_JIP2, Src homology 3 domain of JNK-interacting protein
           2.  JNK-interacting protein 2 (JIP2) is also called
           Mitogen-activated protein kinase 8-interacting protein 2
           (MAPK8IP2) or Islet-brain-2 (IB2). It is widely
           expressed in the brain, where it forms complexes with
           fibroblast growth factor homologous factors (FHFs),
           which facilitates activation of the p38delta MAPK. JIP2
           is enriched in postsynaptic densities and may play a
           role in motor and cognitive function. In addition to a
           JNK binding domain, JIP2 also contains SH3 and
           Phosphotyrosine-binding (PTB) domains. The SH3 domain of
           the related protein JIP1 homodimerizes at the interface
           usually involved in proline-rich ligand recognition,
           despite the lack of this motif in the domain itself. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 55

 Score = 26.8 bits (59), Expect = 2.7
 Identities = 14/52 (26%), Positives = 28/52 (53%), Gaps = 1/52 (1%)

Query: 115 AKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNI-SGEVGSIPVPYVQK 165
           A + F     D+L    +D L+V ++++++W+   N+ +GE G  P  Y  +
Sbjct: 4   AVFRFIPRHEDELELDVDDPLLVEAEEDDYWYRGYNMRTGERGIFPAFYAHE 55


>gnl|CDD|212736 cd11802, SH3_Endophilin_B, Src homology 3 domain of Endophilin-B.
           Endophilins play roles in synaptic vesicle formation,
           virus budding, mitochondrial morphology maintenance,
           receptor-mediated endocytosis inhibition, and endosomal
           sorting. They are classified into two types, A and B.
           Vertebrates contain two endophilin-B isoforms.
           Endophilin-B proteins are cytoplasmic proteins expressed
           mainly in the heart, placenta, and skeletal muscle.
           Endophilins contain an N-terminal N-BAR domain (BAR
           domain with an additional N-terminal amphipathic helix),
           followed by a variable region containing proline
           clusters, and a C-terminal SH3 domain. SH3 domains are
           protein interaction domains that bind to proline-rich
           ligands with moderate affinity and selectivity,
           preferentially to PxxP motifs. They play versatile and
           diverse roles in the cell including the regulation of
           enzymes, changing the subcellular localization of
           signaling pathway components, and mediating the
           formation of multiprotein complex assemblies.
          Length = 52

 Score = 26.5 bits (59), Expect = 2.7
 Identities = 12/53 (22%), Positives = 25/53 (47%), Gaps = 5/53 (9%)

Query: 112 KVIAKYDFDGNDPDDLPFKKNDILIVVSKD--EEHWWTAQNISGEVGSIPVPY 162
           +V+  YD+D  D  +L    ++++ V      +E +   +    + G +PV Y
Sbjct: 3   RVL--YDYDAEDSTELSLLADEVITVYELPGMDEDYMMGER-GSQRGKVPVAY 52


>gnl|CDD|212749 cd11815, SH3_Eve1_2, Second Src homology 3 domain of ADAM-binding
           protein Eve-1.  Eve-1, also called SH3 domain-containing
           protein 19 (SH3D19) or EEN-binding protein (EBP), exists
           in multiple alternatively spliced isoforms. The longest
           isoform contains five SH3 domain in the C-terminal
           region and seven proline-rich motifs in the N-terminal
           region. It is abundantly expressed in skeletal muscle
           and heart, and may be involved in regulating the
           activity of ADAMs (A disintegrin and metalloproteases).
           Eve-1 interacts with EEN, an endophilin involved in
           endocytosis and may be the target of the MLL-EEN fusion
           protein that is implicated in leukemogenesis. SH3
           domains are protein interaction domains that bind to
           proline-rich ligands with moderate affinity and
           selectivity, preferentially to PxxP motifs. They play
           versatile and diverse roles in the cell including the
           regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 52

 Score = 26.4 bits (58), Expect = 3.2
 Identities = 11/48 (22%), Positives = 20/48 (41%), Gaps = 1/48 (2%)

Query: 117 YDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQ 164
           +DF     DDL     +I+ ++ K +  W+         G  P  +V+
Sbjct: 6   HDFPAEHSDDLSLNSGEIVYLLEKIDTEWYRG-KCKNTTGIFPANHVK 52


>gnl|CDD|212948 cd12015, SH3_Tks_1, First Src homology 3 domain of Tyrosine kinase
           substrate (Tks) proteins.  Tks proteins are Src
           substrates and scaffolding proteins that play important
           roles in the formation of podosomes and invadopodia, the
           dynamic actin-rich structures that are related to cell
           migration and cancer cell invasion. Vertebrates contain
           two Tks proteins, Tks4 (Tyr kinase substrate with four
           SH3 domains) and Tks5 (Tyr kinase substrate with five
           SH3 domains), which display partially overlapping but
           non-redundant functions. Both associate with the ADAMs
           family of transmembrane metalloproteases, which function
           as sheddases and mediators of cell and matrix
           interactions. Tks5 interacts with N-WASP and Nck, while
           Tks4 is essential for the localization of MT1-MMP
           (membrane-type 1 matrix metalloproteinase) to
           invadopodia. Tks proteins contain an N-terminal Phox
           homology (PX) domain and four or five SH3 domains. This
           model characterizes the first SH3 domain of Tks
           proteins. SH3 domains are protein interaction domains
           that bind to proline-rich ligands with moderate affinity
           and selectivity, preferentially to PxxP motifs. They
           play versatile and diverse roles in the cell including
           the regulation of enzymes, changing the subcellular
           localization of signaling pathway components, and
           mediating the formation of multiprotein complex
           assemblies.
          Length = 53

 Score = 25.8 bits (57), Expect = 4.5
 Identities = 14/53 (26%), Positives = 29/53 (54%), Gaps = 3/53 (5%)

Query: 113 VIAKYDFDGNDPDDLPFKKNDILIVVSKDEEHWWTAQNISGEVGSIPVPYVQK 165
           V+A  D+    P+++  +  D++ V+ K+E  WW   ++  E G +P  Y++ 
Sbjct: 4   VVA--DYKKQQPNEISLRAGDVVDVIEKNENGWWFV-SLEDEQGWVPATYLEP 53


>gnl|CDD|198239 cd10376, SH2_STAT5, Src homology 2 (SH2) domain found in signal
          transducer and activator of transcription (STAT) 5
          proteins.  STAT5 is a member of the STAT family of
          transcription factors.  Two highly related proteins,
          STAT5a and STAT5b are encoded by separate genes, but
          are 90% identical at the amino acid level.  Both STAT5a
          and STAT5b are ubiquitously expressed and  functionally
          interchangeable. Mice lacking either STAT5a or STAT5b
          have mild defects in prolactin dependent mammary
          differentiation or sexually dimorphic growth
          hormone-dependent effects, respectively. Mice lacking
          both STAT5a and STAT5b exhibit a perinatal lethal
          phenotype and have multiple defects, including anemia
          and a virtual absence of B and T lymphocytes. STAT
          proteins mediate the signaling of cytokines and a
          number of growth factors from the receptors of these
          extracellular signaling molecules to the cell nucleus. 
          STATs are specifically phosphorylated by
          receptor-associated Janus kinases, receptor tyrosine
          kinases, or cytoplasmic tyrosine kinases. The
          phosphorylated STAT molecules dimerize by reciprocal
          binding of their SH2 domains to the phosphotyrosine
          residues. These dimeric STATs translocate into the
          nucleus, bind to specific DNA sequences, and regulate
          the transcription of their target genes.  However there
          are a number of unphosphorylated STATs that travel
          between the cytoplasm and nucleus and some STATs that
          exist as dimers in unstimulated cells that can exert
          biological functions independent of being activated.
          There are seven mammalian STAT family members which
          have been identified: STAT1, STAT2, STAT3, STAT4, STAT5
          (STAT5A and STAT5B), and STAT6. There are 6 conserved
          domains in STAT: N-terminal domain (NTD), coiled-coil
          domain (CCD), DNA-binding domain (DBD), alpha-helical
          linker domain (LD), SH2 domain, and transactivation
          domain (TAD).  NTD is involved in dimerization of
          unphosphorylated STATs monomers and for the
          tetramerization between STAT1, STAT3, STAT4 and STAT5
          on promoters with two or more tandem STAT binding
          sites.  It also plays a role in promoting interactions
          with transcriptional co-activators such as CREB binding
          protein (CBP)/p300, as well as being important for
          nuclear import and deactivation of STATs involving
          tyrosine de-phosphorylation. CCD interacts with other
          proteins, such as IFN regulatory protein 9 (IRF-9/p48)
          with STAT1 and c-JUN with STAT3 and is also thought to
          participate in the negative regulation of these
          proteins. Distinct genes are bound to STATs via their
          DBD domain. This domain is also involved in nuclear
          translocation of activated STAT1 and STAT3
          phosphorylated dimers upon cytokine stimulation.  LD
          links the DNA-binding and SH2  domains and is important
          for the transcriptional activation of STAT1 in response
          to IFN-gamma. It also plays a role in protein-protein
          interactions and has also been implicated in the
          constitutive nucleocytoplasmic shuttling of
          unphosphorylated STATs in resting cells.  The SH2
          domain is necessary for receptor association and
          tyrosine phosphodimer formation. Residues within this
          domain may be particularly important for some cellular
          functions mediated by the STATs as well as residues
          adjacent to this domain.  The TAD interacts with
          several proteins, namely minichromosome maintenance
          complex component 5 (MCM5), breast cancer 1 (BRCA1) and
          CBP/p300. TAD also contains a modulatory
          phosphorylation site that regulates STAT activity and
          is necessary for maximal transcription of a number of
          target genes. The conserved tyrosine residue present in
          the C-terminus is crucial for dimerization via
          interaction with the SH2 domain upon the interaction of
          the ligand with the receptor. STAT activation by
          tyrosine phosphorylation also determines nuclear import
          and retention, DNA binding to specific DNA elements in
          the promoters of responsive genes, and transcriptional
          activation of STAT dimers. In addition to the SH2
          domain there is a coiled-coil domain, a DNA binding
          domain, and a transactivation domain in the STAT
          proteins.
          Length = 137

 Score = 27.2 bits (60), Expect = 5.4
 Identities = 14/47 (29%), Positives = 27/47 (57%), Gaps = 1/47 (2%)

Query: 7  PHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK 53
          PH  +    G + +Q+A  +L+++ D G FL+R S++ +G   +  K
Sbjct: 15 PHWNDGAILGFVNKQQAHDLLINKPD-GTFLLRFSDSEIGGITIAWK 60


>gnl|CDD|128856 smart00588, NEUZ, domain in neuralized proteins. 
          Length = 123

 Score = 27.3 bits (61), Expect = 5.6
 Identities = 18/60 (30%), Positives = 25/60 (41%), Gaps = 2/60 (3%)

Query: 208 ARVKQVRVPNAYDKTALKLEIGDIIKVTKTNINGQWEGELN-GKTGHFPFT-HVEFIPTN 265
           AR       NA   +A  L I ++ +V    +  +W G L  G T   P T     +PTN
Sbjct: 22  ARRSASDFCNALVFSARPLRINELFEVKIEKVVRKWSGALRFGVTTCDPATLRPASLPTN 81


>gnl|CDD|198284 cd10421, SH2_STAT5a, Src homology 2 (SH2) domain found in signal
          transducer and activator of transcription (STAT) 5a
          proteins.  STAT5 is a member of the STAT family of
          transcription factors.  Two highly related proteins,
          STAT5a and STAT5b are encoded by separate genes, but
          are 90% identical at the amino acid level.  Both STAT5a
          and STAT5b are ubiquitously expressed and functionally
          interchangeable. Mice lacking either STAT5a or STAT5b
          have mild defects in prolactin dependent mammary
          differentiation or sexually dimorphic growth
          hormone-dependent effects, respectively. Mice lacking
          both STAT5a and STAT5b exhibit a perinatal lethal
          phenotype and have multiple defects, including anemia
          and a virtual absence of B and T lymphocytes. STAT
          proteins mediate the signaling of cytokines and a
          number of growth factors from the receptors of these
          extracellular signaling molecules to the cell nucleus.
          STATs are specifically phosphorylated by
          receptor-associated Janus kinases, receptor tyrosine
          kinases, or cytoplasmic tyrosine kinases. The
          phosphorylated STAT molecules dimerize by reciprocal
          binding of their SH2 domains to the phosphotyrosine
          residues. These dimeric STATs translocate into the
          nucleus, bind to specific DNA sequences, and regulate
          the transcription of their target genes.  However there
          are a number of unphosphorylated STATs that travel
          between the cytoplasm and nucleus and some STATs that
          exist as dimers in unstimulated cells that can exert
          biological functions independent of being activated.
          There are seven mammalian STAT family members which
          have been identified: STAT1, STAT2, STAT3, STAT4, STAT5
          (STAT5A and STAT5B), and STAT6. There are 6 conserved
          domains in STAT: N-terminal domain (NTD), coiled-coil
          domain (CCD), DNA-binding domain (DBD), alpha-helical
          linker domain (LD), SH2 domain, and transactivation
          domain (TAD). NTD is involved in dimerization of
          unphosphorylated STATs monomers and for the
          tetramerization between STAT1, STAT3, STAT4 and STAT5
          on promoters with two or more tandem STAT binding
          sites.  It also plays a role in promoting interactions
          with transcriptional co-activators such as CREB binding
          protein (CBP)/p300, as well as being important for
          nuclear import and deactivation of STATs involving
          tyrosine de-phosphorylation. CCD interacts with other
          proteins, such as IFN regulatory protein 9 (IRF-9/p48)
          with STAT1 and c-JUN with STAT3 and is also thought to
          participate in the negative regulation of these
          proteins. Distinct genes are bound to STATs via their
          DBD domain. This domain is also involved in nuclear
          translocation of activated STAT1 and STAT3
          phosphorylated dimers upon cytokine stimulation. LD
          links the DNA-binding and SH2 domains and is important
          for the transcriptional activation of STAT1 in response
          to IFN-gamma. It also plays a role in protein-protein
          interactions and has also been implicated in the
          constitutive nucleocytoplasmic shuttling of
          unphosphorylated STATs in resting cells.  The SH2
          domain is necessary for receptor association and
          tyrosine phosphodimer formation. Residues within this
          domain may be particularly important for some cellular
          functions mediated by the STATs as well as residues
          adjacent to this domain.  The TAD interacts with
          several proteins, namely minichromosome maintenance
          complex component 5 (MCM5), breast cancer 1 (BRCA1) and
          CBP/p300. TAD also contains a modulatory
          phosphorylation site that regulates STAT activity and
          is necessary for maximal transcription of a number of
          target genes. The conserved tyrosine residue present in
          the C-terminus is crucial for dimerization via
          interaction with the SH2 domain upon the interaction of
          the ligand with the receptor. STAT activation by
          tyrosine phosphorylation also determines nuclear import
          and retention, DNA binding to specific DNA elements in
          the promoters of responsive genes, and transcriptional
          activation of STAT dimers. In addition to the SH2
          domain there is a coiled-coil domain, a DNA binding
          domain, and a transactivation domain in the STAT
          proteins. In general SH2 domains are involved in signal
          transduction.  They typically bind pTyr-containing
          ligands via two surface pockets, a pTyr and hydrophobic
          binding pocket, allowing proteins with SH2 domains to
          localize to tyrosine phosphorylated sites.
          Length = 140

 Score = 26.5 bits (58), Expect = 9.7
 Identities = 14/47 (29%), Positives = 27/47 (57%), Gaps = 1/47 (2%)

Query: 7  PHDRNSWYFGMMTRQEAQAILLSEKDNGAFLVRDSNTILGNYVLCVK 53
          PH  +    G + +Q+A  +L+++ D G FL+R S++ +G   +  K
Sbjct: 15 PHWNDGAILGFVNKQQAHDLLINKPD-GTFLLRFSDSEIGGITIAWK 60


  Database: CDD.v3.10
    Posted date:  Mar 20, 2013  7:55 AM
  Number of letters in database: 10,937,602
  Number of sequences in database:  44,354
  
Lambda     K      H
   0.315    0.133    0.394 

Gapped
Lambda     K      H
   0.267   0.0729    0.140 


Matrix: BLOSUM62
Gap Penalties: Existence: 11, Extension: 1
Number of Sequences: 44354
Number of Hits to DB: 14,437,059
Number of extensions: 1348248
Number of successful extensions: 1446
Number of sequences better than 10.0: 1
Number of HSP's gapped: 1350
Number of HSP's successfully gapped: 443
Length of query: 288
Length of database: 10,937,602
Length adjustment: 96
Effective length of query: 192
Effective length of database: 6,679,618
Effective search space: 1282486656
Effective search space used: 1282486656
Neighboring words threshold: 11
Window for multiple hits: 40
X1: 16 ( 7.3 bits)
X2: 38 (14.6 bits)
X3: 64 (24.7 bits)
S1: 42 (22.0 bits)
S2: 58 (26.1 bits)