RPS-BLAST 2.2.26 [Sep-21-2011]

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

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

Query= psy1488
         (630 letters)



>gnl|CDD|241258 cd01224, PH_Collybistin_ASEF, Collybistin/APC-stimulated guanine
           nucleotide exchange factor pleckstrin homology (PH)
           domain.  Collybistin (also called PEM2) is homologous to
           the Dbl proteins ASEF (also called ARHGEF4/RhoGEF4) and
           SPATA13 (Spermatogenesis-associated protein 13; also
           called ASEF2). It activates CDC42 specifically and not
           any other Rho-family GTPases. Collybistin consists of an
           SH3 domain, followed by a RhoGEF/DH and PH domain. In
           Dbl proteins, the DH and PH domains catalyze the
           exchange of GDP for GTP in Rho GTPases, allowing them to
           signal to downstream effectors. It induces submembrane
           clustering of the receptor-associated peripheral
           membrane protein gephyrin, which is thought to form a
           scaffold underneath the postsynaptic membrane linking
           receptors to the cytoskeleton. It also acts as a tumor
           suppressor that links adenomatous polyposis coli (APC)
           protein, a negative regulator of the Wnt signaling
           pathway and promotes the phosphorylation and degradation
           of beta-catenin, to Cdc42. Autoinhibition of collybistin
           is accomplished by the binding of its SH3 domain with
           both the RhoGEF and PH domains to block access of Cdc42
           to the GTPase-binding site. Inactivation promotes cancer
           progression. PH domains have diverse functions, but in
           general are involved in targeting proteins to the
           appropriate cellular location or in the interaction with
           a binding partner. They share little sequence
           conservation, but all have a common fold, which is
           electrostatically polarized. Less than 10% of PH domains
           bind phosphoinositide phosphates (PIPs) with high
           affinity and specificity. PH domains are distinguished
           from other PIP-binding domains by their specific
           high-affinity binding to PIPs with two vicinal phosphate
           groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3
           which results in targeting some PH domain proteins to
           the plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.
          Length = 139

 Score =  220 bits (562), Expect = 4e-69
 Identities = 76/139 (54%), Positives = 104/139 (74%)

Query: 457 MESLEKLAAWQQRVEGWEGEDLIETSSQLIHQGEVIRVTSGMWTNTITLFLFDHQLVYCK 516
           +E+LEKLAAWQ  +EGWEGEDL++ SS+LIH GE+ +++S       T FLFDHQLVYCK
Sbjct: 1   LENLEKLAAWQSSIEGWEGEDLLDRSSELIHSGELSKISSKGKAQERTFFLFDHQLVYCK 60

Query: 517 RDILKRNTHVYKARLNIDTSQIINLPDGKDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLE 576
           +D+LKR+  +YK R+++D  +I +L DGKD   GVTV++A KI+ + K+KW L C +S E
Sbjct: 61  KDLLKRDNLIYKGRIDLDNMEIEDLEDGKDKDSGVTVKNAWKIYNTSKNKWYLLCAKSAE 120

Query: 577 DKARWLAAFQQERALVEQD 595
           +K RWL AF +ER  VE+D
Sbjct: 121 EKQRWLEAFAEEREKVEED 139


>gnl|CDD|216028 pfam00621, RhoGEF, RhoGEF domain.  Guanine nucleotide exchange
           factor for Rho/Rac/Cdc42-like GTPases Also called
           Dbl-homologous (DH) domain. It appears that pfam00169
           domains invariably occur C-terminal to RhoGEF/DH
           domains.
          Length = 179

 Score =  202 bits (517), Expect = 8e-62
 Identities = 76/181 (41%), Positives = 116/181 (64%), Gaps = 3/181 (1%)

Query: 273 VVRELINTERDFVKVLHDVSEGYLAECRRRNDMFSPEQIQTIFGNLEDILAFQSSFLEDL 332
           V++EL+ TER +V+ L  + E +L   R    + S E+I+TIF N+E+IL     FLE+L
Sbjct: 1   VIQELLQTERSYVRDLKILVEVFLKPLRES-PILSEEEIKTIFSNIEEILELHQEFLEEL 59

Query: 333 ETKLDWDAPYKSCIGETFLKHKSGFRMYSEYCNSHPMAIATLQELYQHNN-YSKFFEACR 391
           E +L+ + P    IG+ FLK    F++YS YC+++P A+  L++L + N  ++KF + C 
Sbjct: 60  EERLE-EWPDIQRIGDIFLKFAPFFKVYSTYCSNYPRALELLKKLRKKNPRFAKFLKECE 118

Query: 392 LMRGLIEIPLDGYLLTPVQRICKYPLQLAELLKYTKTDHPDYVKITEALEAMRDVAMLIN 451
                  + L+ +L+ PVQRI +YPL L ELLK+T  DHPDY  + +ALEA+++VA  IN
Sbjct: 119 ASPLCRGLDLNSFLIKPVQRIPRYPLLLKELLKHTPPDHPDYEDLKKALEAIKEVASQIN 178

Query: 452 E 452
           E
Sbjct: 179 E 179


>gnl|CDD|214619 smart00325, RhoGEF, Guanine nucleotide exchange factor for
           Rho/Rac/Cdc42-like GTPases.  Guanine nucleotide exchange
           factor for Rho/Rac/Cdc42-like GTPases Also called
           Dbl-homologous (DH) domain. It appears that PH domains
           invariably occur C-terminal to RhoGEF/DH domains.
           Improved coverage.
          Length = 180

 Score =  185 bits (473), Expect = 1e-55
 Identities = 69/181 (38%), Positives = 117/181 (64%), Gaps = 2/181 (1%)

Query: 273 VVRELINTERDFVKVLHDVSEGYLAECRRRNDMFSPEQIQTIFGNLEDILAFQSSFLEDL 332
           V++EL+ TER++V+ L  + E +L   ++   + SP +++T+FGN+E+I  F   FL++L
Sbjct: 1   VLKELLQTERNYVRDLKLLVEVFLKPLKKELKLLSPNELETLFGNIEEIYEFHRDFLDEL 60

Query: 333 ETKLD-WDAPYKSCIGETFLKHKSGFRMYSEYCNSHPMAIATLQELYQHNNYSKFFEACR 391
           E +++ WD   +  IG+ FLK +  F++YSEYC++HP A+  L++L ++  + KF +   
Sbjct: 61  EERIEEWDDSVER-IGDVFLKLEEFFKIYSEYCSNHPDALELLKKLKKNPRFQKFLKEIE 119

Query: 392 LMRGLIEIPLDGYLLTPVQRICKYPLQLAELLKYTKTDHPDYVKITEALEAMRDVAMLIN 451
                  + L+  LL PVQR+ KYPL L ELLK+T  DH D   + +AL+A++++A  +N
Sbjct: 120 SSPQCRRLTLESLLLKPVQRLTKYPLLLKELLKHTPEDHEDREDLKKALKAIKELANQVN 179

Query: 452 E 452
           E
Sbjct: 180 E 180


>gnl|CDD|238091 cd00160, RhoGEF, Guanine nucleotide exchange factor for
           Rho/Rac/Cdc42-like GTPases; Also called Dbl-homologous
           (DH) domain. It appears that PH domains invariably occur
           C-terminal to RhoGEF/DH domains.
          Length = 181

 Score =  183 bits (467), Expect = 1e-54
 Identities = 70/184 (38%), Positives = 110/184 (59%), Gaps = 5/184 (2%)

Query: 270 RSRVVRELINTERDFVKVLHDVSEGYLAECRRRNDMFSPEQIQTIFGNLEDILAFQSSFL 329
           R  V++EL+ TER++V+ L  + E +L    +     SPE+++ +FGN+E+I  F   FL
Sbjct: 1   RQEVIKELLQTERNYVRDLKLLVEVFLKPLDKELLPLSPEEVELLFGNIEEIYEFHRIFL 60

Query: 330 EDLETKLDWDAPYKSCIGETFLKHKSGFRMYSEYCNSHPMAIATLQELYQHNNYSKFFEA 389
           + LE +++        IG+ FLK    F++YSEYC++HP A+  L++L + N   KFF+ 
Sbjct: 61  KSLEERVEEWDKSGPRIGDVFLKLAPFFKIYSEYCSNHPDALELLKKLKKFN---KFFQE 117

Query: 390 C--RLMRGLIEIPLDGYLLTPVQRICKYPLQLAELLKYTKTDHPDYVKITEALEAMRDVA 447
              +       + L+  LL PVQR+ KYPL L ELLK+T   H D   + +ALEA+++VA
Sbjct: 118 FLEKAESECGRLKLESLLLKPVQRLTKYPLLLKELLKHTPDGHEDREDLKKALEAIKEVA 177

Query: 448 MLIN 451
             +N
Sbjct: 178 SQVN 181


>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 =  102 bits (257), Expect = 8e-27
 Identities = 37/53 (69%), Positives = 45/53 (84%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           LAEA+WDHV M+ EELGF+AGDVIEVLD  D+DWWWG+  +  GWFP++FVRL
Sbjct: 1   LAEALWDHVTMDPEELGFKAGDVIEVLDMSDKDWWWGSIRDEEGWFPASFVRL 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 = 93.5 bits (232), Expect = 2e-23
 Identities = 41/80 (51%), Positives = 56/80 (70%), Gaps = 10/80 (12%)

Query: 155 QPLGINELSPLLRRKPIGMDEDFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWW 214
           + L INEL          + +  VV AEA+WDHV M+ +ELGF+AGDVIEV+D  +++WW
Sbjct: 4   EQLAINEL----------ISDGSVVCAEALWDHVTMDDQELGFKAGDVIEVMDATNKEWW 53

Query: 215 WGTRGEASGWFPSAFVRLRV 234
           WG   ++ GWFP++FVRLRV
Sbjct: 54  WGRVLDSEGWFPASFVRLRV 73


>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 = 86.7 bits (214), Expect = 5e-21
 Identities = 36/61 (59%), Positives = 45/61 (73%)

Query: 176 DFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRLRVS 235
             +V AEAVWDHV M   EL F+AGDVI+VLD  ++DWWWG   +  GWFP++FVRL V+
Sbjct: 2   GSIVSAEAVWDHVTMANRELAFKAGDVIKVLDASNKDWWWGQIDDEEGWFPASFVRLWVN 61

Query: 236 Q 236
           Q
Sbjct: 62  Q 62


>gnl|CDD|212907 cd11974, SH3_ASEF2, Src homology 3 domain of APC-Stimulated guanine
           nucleotide Exchange Factor 2.  ASEF2, also called
           Spermatogenesis-associated protein 13 (SPATA13), is a
           GEF that localizes with actin at the leading edge of
           cells and is important in cell migration and adhesion
           dynamics. GEFs activate small GTPases by exchanging
           bound GDP for free GTP. ASEF2 can activate both Rac 1
           and Cdc42, but only Rac1 activation is necessary for
           increased cell migration and adhesion turnover. Together
           with APC (adenomatous polyposis coli) and Neurabin2, a
           scaffold protein that binds F-actin, it is involved in
           regulating HGF-induced cell migration. ASEF2 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 = 54

 Score = 82.0 bits (202), Expect = 2e-19
 Identities = 31/54 (57%), Positives = 41/54 (75%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           V AEA+WDHV M+ +EL F+AGDVI VL+  ++DWWWG   +   WFP++FVRL
Sbjct: 1   VYAEALWDHVTMDDQELAFKAGDVIRVLEASNKDWWWGRNEDREAWFPASFVRL 54


>gnl|CDD|227709 COG5422, ROM1, RhoGEF, Guanine nucleotide exchange factor for
           Rho/Rac/Cdc42-like GTPases [Signal transduction
           mechanisms].
          Length = 1175

 Score = 80.3 bits (198), Expect = 1e-15
 Identities = 77/275 (28%), Positives = 127/275 (46%), Gaps = 27/275 (9%)

Query: 270 RSRVVRELINTERDFVKVLHDVSEGY---------LAECRRRNDMFSPEQIQTIFGNLED 320
           R   + E+I TERDFVK L  + + +         + E  RRN  F    I+ +F N+ +
Sbjct: 485 RQEAIYEVIYTERDFVKDLEYLRDTWIKPLEESNIIPENARRN--F----IKHVFANINE 538

Query: 321 ILAFQSSFLEDLETKLDWDAPYKSCIGETFLKHKSGFRMYSEYCNSHPMAIATLQELYQH 380
           I A  S  L+ L T     +P  + I + FL +   F  + +Y  S P A    +     
Sbjct: 539 IYAVNSKLLKAL-TNRQCLSPIVNGIADIFLDYVPKFEPFIKYGASQPYAKYEFEREKSV 597

Query: 381 N-NYSKFFEACRLMRGLIEIPLDGYLLTPVQRICKYPLQLAELLKYTKTDHPDYVKITEA 439
           N N+++F      +    ++ LDGYL  P  R+ +YPL L E+LK+T  D+PD   I + 
Sbjct: 598 NPNFARFDHEVERLDESRKLELDGYLTKPTTRLARYPLLLEEVLKFTDPDNPDTEDIPKV 657

Query: 440 LEAMRDVAMLINERKRRMES-LEKLAAWQQRVEGWEGEDLIE--TSSQLIHQGEVIRV-- 494
           ++ +R+    +N    + E+  +     QQ +   E  +L       ++I +G V++   
Sbjct: 658 IDMLREFLSRLNFESGKAENRGDLFHLNQQLLFKPEYVNLGLNDEYRKIIFKG-VLKRKA 716

Query: 495 ---TSGMWTNTITLFLFDHQLVYCK-RDILKRNTH 525
              T G     I  FL D+ L++CK + + K   H
Sbjct: 717 KSKTDGSLRGDIQFFLLDNMLLFCKAKAVNKWRQH 751


>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 = 66.4 bits (163), Expect = 4e-14
 Identities = 21/52 (40%), Positives = 30/52 (57%), Gaps = 1/52 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRG-EASGWFPSAFVR 231
             A++D+ A + +EL F+ GD+I VL+  D  WW G  G    G FPS +V 
Sbjct: 5   VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLGRGKEGLFPSNYVE 56


>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 = 65.9 bits (162), Expect = 6e-14
 Identities = 20/50 (40%), Positives = 30/50 (60%), Gaps = 1/50 (2%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT-RGEASGWFPSAF 229
           A A++D+ A + +EL F+ GD+I VL+  D  WW G   G   G FP+ +
Sbjct: 2   ARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELNGGREGLFPANY 51


>gnl|CDD|241292 cd01261, PH_SOS, Son of Sevenless (SOS) Pleckstrin homology (PH)
           domain.  SOS is a Ras guanine nucleotide exchange
           factor. SOS is thought to transmit signals from
           activated receptor tyrosine kinases to the Ras signaling
           pathway. SOS contains a histone domain, Dbl-homology
           (DH), a PH domain, Rem domain, Cdc25 domain, and a Grb2
           binding domain. The SOS PH domain binds to
           phosphatidylinositol-4,5-bisphosphate (PIP2) and
           phosphatidic acid (PA). SOS is dependent on Ras binding
           to the allosteric site via its histone domain for both a
           lower level of activity (Ras GDP) and maximal activity
           (Ras GTP). The DH domain blocks the allosteric Ras
           binding site in SOS. The PH domain is closely associated
           with the DH domain and the action of the DH-PH unit
           gates a reciprocal interaction between Ras and SOS. The
           C-terminal proline-rich domain of SOS binds to the
           adapter protein Grb2 which localizes the Sos protein to
           the plasma membrane and diminishes the negative effect
           of the C-terminal domain on the guanine nucleotide
           exchange activity of the CDC25-homology domain of SOS.
           PH domains have diverse functions, but in general are
           involved in targeting proteins to the appropriate
           cellular location or in the interaction with a binding
           partner. They share little sequence conservation, but
           all have a common fold, which is electrostatically
           polarized. Less than 10% of PH domains bind
           phosphoinositide phosphates (PIPs) with high affinity
           and specificity. PH domains are distinguished from other
           PIP-binding domains by their specific high-affinity
           binding to PIPs with two vicinal phosphate groups:
           PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which
           results in targeting some PH domain proteins to the
           plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.
          Length = 109

 Score = 67.0 bits (164), Expect = 1e-13
 Identities = 27/112 (24%), Positives = 53/112 (47%), Gaps = 13/112 (11%)

Query: 480 ETSSQLIHQGEVIRVTSGMWTNTITLFLFDHQLVYCKRDILKR----NTHVY--KARLNI 533
           +  ++ I +G + +V +G  +    LFLFD  L+ CK +        +   Y  K ++ I
Sbjct: 1   QCCNEFIMEGTLTKVGAGKRSTERHLFLFDGLLLLCKSNQSSTASGQSKPEYRLKEKIFI 60

Query: 534 DTSQIINLPDGKDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLEDKARWLAAF 585
              +I +L D  +      +++A +I   D+  + +   +S E+K  W+AA 
Sbjct: 61  RKVEINDLEDTDE------LKNAFEIVPRDEPSY-ILFAKSAEEKNNWMAAL 105


>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 = 63.7 bits (155), Expect = 4e-13
 Identities = 23/51 (45%), Positives = 32/51 (62%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
             A++D  A+E +ELGF +GDVIEVLD+ +  WW G      G FP+ +V 
Sbjct: 2   VRALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHGKLGLFPANYVA 52


>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 = 56.9 bits (138), Expect = 1e-10
 Identities = 22/51 (43%), Positives = 29/51 (56%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
             +A++D    E  EL FR GD+I VLD+ D DWW G      G FP+ +V
Sbjct: 1   RVQALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGELRGRVGIFPANYV 51


>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 = 56.3 bits (137), Expect = 2e-10
 Identities = 21/46 (45%), Positives = 28/46 (60%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           D+VA +  EL  + GDV++VLD  D  WW G RG   G  PS++V 
Sbjct: 7   DYVATDPNELSLKKGDVVKVLDKDDNGWWEGERGGRRGLVPSSYVE 52


>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 = 55.0 bits (132), Expect = 6e-10
 Identities = 23/48 (47%), Positives = 31/48 (64%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D  A E  EL F+AGD+I +LD  D +WW G   + +G FPS FV
Sbjct: 5   AIYDFEAAEDNELTFKAGDIITILDDSDPNWWKGETPQGTGLFPSNFV 52


>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 = 54.4 bits (131), Expect = 9e-10
 Identities = 22/48 (45%), Positives = 30/48 (62%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D  A E  EL F+AG++I VLD  D +WW G+     G FP+ FV
Sbjct: 5   ALYDFEAAEDNELTFKAGEIITVLDDSDPNWWKGSNHRGEGLFPANFV 52


>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 = 54.4 bits (131), Expect = 9e-10
 Identities = 23/52 (44%), Positives = 34/52 (65%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           AEA++D       EL F+AGDVI +L  +++DW  GT   A+G FP +FV++
Sbjct: 2   AEALFDFTGNSKLELNFKAGDVIFLLSRVNKDWLEGTVRGATGIFPLSFVKI 53


>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 = 53.7 bits (129), Expect = 1e-09
 Identities = 19/48 (39%), Positives = 27/48 (56%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++     E E+L  R GD I +LD  + DWW G   +  G+FP+ FV
Sbjct: 4   ALYKFKPQENEDLEMRPGDKITLLDDSNEDWWKGKIEDRVGFFPANFV 51


>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 = 53.5 bits (129), Expect = 2e-09
 Identities = 19/53 (35%), Positives = 28/53 (52%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           L  A ++      +EL F  GD+I V   ++  WW GT    +GWFPS +V+ 
Sbjct: 1   LVRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYVKE 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 = 53.3 bits (128), Expect = 2e-09
 Identities = 22/51 (43%), Positives = 29/51 (56%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
            +A++D    E  ELGFR GD IEV+D  D +WW G     +G FP  +V 
Sbjct: 2   VQALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGACHGQTGMFPRNYVT 52


>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 = 51.5 bits (124), Expect = 8e-09
 Identities = 16/50 (32%), Positives = 31/50 (62%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
            A+ D+ A   +E+  + G+V+EVL+  D  WW+  +G+  GW P++++ 
Sbjct: 3   VAIADYEAQGDDEISLQEGEVVEVLEKNDSGWWYVRKGDKEGWVPASYLE 52


>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 = 49.9 bits (120), Expect = 2e-08
 Identities = 20/46 (43%), Positives = 27/46 (58%), Gaps = 1/46 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR-GEASGWFPS 227
           A++D+ A E +EL F+ GD+I VL+  D  WW G   G   G  PS
Sbjct: 2   ALYDYTAREPDELSFKKGDIIIVLEKSDDGWWKGRLKGGKEGLIPS 47


>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 = 50.4 bits (120), Expect = 3e-08
 Identities = 20/50 (40%), Positives = 30/50 (60%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A++D+ A   +EL F  G +I VL+  D DWW G     +G FPS +V++
Sbjct: 5   AMYDYTANNEDELSFSKGQLINVLNKDDPDWWQGEINGVTGLFPSNYVKM 54


>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 = 50.0 bits (119), Expect = 3e-08
 Identities = 22/48 (45%), Positives = 29/48 (60%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D  A+E  EL F+ G++I VLD  D +WW G      G FPS FV
Sbjct: 6   ALYDFEAVEDNELTFKHGEIIIVLDDSDANWWKGENHRGVGLFPSNFV 53


>gnl|CDD|212728 cd11794, SH3_DNMBP_N1, First 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 = 49.8 bits (119), Expect = 3e-08
 Identities = 23/50 (46%), Positives = 30/50 (60%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
             A++D     +EEL   AGDVIEVL  +D  W  GT+   +G FPS+FV
Sbjct: 2   VRAIFDFCPSVSEELPLFAGDVIEVLKVVDEFWLLGTKEGVTGQFPSSFV 51


>gnl|CDD|214574 smart00233, PH, Pleckstrin homology domain.  Domain commonly found
           in eukaryotic signalling proteins. The domain family
           possesses multiple functions including the abilities to
           bind inositol phosphates, and various proteins. PH
           domains have been found to possess inserted domains
           (such as in PLC gamma, syntrophins) and to be inserted
           within other domains. Mutations in Brutons tyrosine
           kinase (Btk) within its PH domain cause X-linked
           agammaglobulinaemia (XLA) in patients. Point mutations
           cluster into the positively charged end of the molecule
           around the predicted binding site for
           phosphatidylinositol lipids.
          Length = 102

 Score = 51.0 bits (122), Expect = 4e-08
 Identities = 22/105 (20%), Positives = 45/105 (42%), Gaps = 8/105 (7%)

Query: 485 LIHQGEVIRVTSGMWTNTIT--LFLFDHQLVYCKRDILKRNTHVYKARLNIDTSQIINLP 542
           +I +G + + + G   +       LF+  L+Y K     + ++  K  +++    +   P
Sbjct: 1   VIKEGWLYKKSGGGKKSWKKRYFVLFNSTLLYYKSK-KDKKSYKPKGSIDLSGCTVREAP 59

Query: 543 DGKDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLEDKARWLAAFQQ 587
           D           H  +I  SD+ K LL    S E++ +W+ A ++
Sbjct: 60  DPDSSK----KPHCFEIKTSDR-KTLLLQAESEEEREKWVEALRK 99


>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 = 48.8 bits (117), Expect = 8e-08
 Identities = 19/53 (35%), Positives = 30/53 (56%), Gaps = 1/53 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT-RGEASGWFPSAFVRL 232
           A+A++D+ A E  E+ F  GD+I  ++ +D  WW G       G FP+ +V L
Sbjct: 2   AKALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVNAKGQKGLFPANYVEL 54


>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 = 48.5 bits (116), Expect = 9e-08
 Identities = 17/52 (32%), Positives = 26/52 (50%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
            + ++ +     +EL  + GD IEVL  ++  WW G      G FPS FV+ 
Sbjct: 2   CKVLFSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKLNGKVGVFPSNFVKE 53


>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 = 48.3 bits (115), Expect = 1e-07
 Identities = 21/50 (42%), Positives = 29/50 (58%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
            +A +D  A +  +L FR GD+IEVLD  D +WW G      G+FP  +V
Sbjct: 2   VQAQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWWRGRISGRVGFFPRNYV 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 = 47.9 bits (114), Expect = 1e-07
 Identities = 21/52 (40%), Positives = 29/52 (55%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
              A++ + A + E+L F+ GDVI VL  ++ DW  G      G FPSAFV 
Sbjct: 1   QVVALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCKGKIGIFPSAFVE 52


>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 = 47.9 bits (114), Expect = 1e-07
 Identities = 21/52 (40%), Positives = 30/52 (57%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+A++D+ A E  EL F   D I  ++ +D DWW G    + G FPS +V L
Sbjct: 2   AKALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGECHGSRGLFPSNYVEL 53


>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 = 47.6 bits (113), Expect = 2e-07
 Identities = 20/50 (40%), Positives = 28/50 (56%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
            ++D+ A   +EL F  G +I VL+  D DWW G      G FPS +V+L
Sbjct: 5   GMYDYTAQNDDELAFSKGQIINVLNKEDPDWWKGELNGQVGLFPSNYVKL 54


>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 = 47.4 bits (113), Expect = 3e-07
 Identities = 22/50 (44%), Positives = 31/50 (62%), Gaps = 1/50 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A++ + + E  +L F AGDVI V    D +WW GT G+ +G FPS +VR 
Sbjct: 4   ALYPYESNEPGDLTFNAGDVILVTKK-DGEWWTGTIGDRTGIFPSNYVRP 52


>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 = 47.3 bits (112), Expect = 3e-07
 Identities = 19/56 (33%), Positives = 30/56 (53%), Gaps = 3/56 (5%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVL---DTLDRDWWWGTRGEASGWFPSAFVRL 232
           +  A+WD+ A  A+EL F+ GD I +L   D  + +WWW    +  G+ P   + L
Sbjct: 2   MVYALWDYEAQNADELSFQEGDAITILRRKDDSETEWWWARLNDKEGYVPKNLLGL 57


>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 = 46.8 bits (111), Expect = 4e-07
 Identities = 18/48 (37%), Positives = 30/48 (62%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++   A+E ++L F  G+ I V+D  + +WW G  GE +G+FP  F+
Sbjct: 4   ALYRFKALEKDDLDFHPGERITVIDDSNEEWWRGKIGEKTGYFPMNFI 51


>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 = 46.7 bits (111), Expect = 4e-07
 Identities = 16/54 (29%), Positives = 28/54 (51%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           + A A++D+     +E+ F   + I  ++ +D  WW GT     G FP+ +V L
Sbjct: 1   ICAVALYDYQGEGDDEISFDPQETITDIEMVDEGWWKGTCHGHRGLFPANYVEL 54


>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 = 46.8 bits (112), Expect = 4e-07
 Identities = 16/49 (32%), Positives = 27/49 (55%), Gaps = 2/49 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAF 229
           A++D+ A   ++L F+ GD +++LD  D DWW          G+ PS +
Sbjct: 4   ALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHLSTGKEGYIPSNY 52


>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 = 46.6 bits (111), Expect = 5e-07
 Identities = 20/54 (37%), Positives = 29/54 (53%), Gaps = 2/54 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDR--DWWWGTRGEASGWFPSAFVRL 232
           A A++D    +  +L F+ GD+I +L   D   DWW G  G   G FP+ +V L
Sbjct: 2   AVALYDFAGEQPGDLAFQKGDIITILKKSDSQNDWWTGRIGGREGIFPANYVEL 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 = 46.5 bits (110), Expect = 5e-07
 Identities = 22/50 (44%), Positives = 31/50 (62%), Gaps = 1/50 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A++ + + E  +L F+ GDVI V    D DWW GT G+ +G FPS +VR 
Sbjct: 4   AMYTYESNEQGDLTFQQGDVILVTKK-DGDWWTGTVGDKTGVFPSNYVRP 52


>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 = 46.3 bits (110), Expect = 5e-07
 Identities = 20/48 (41%), Positives = 28/48 (58%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++ + A   +EL F+ GD+I VL   D DWW G     +G FPS +V
Sbjct: 4   ALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGELNGQTGLFPSNYV 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 = 46.2 bits (110), Expect = 6e-07
 Identities = 19/53 (35%), Positives = 29/53 (54%), Gaps = 2/53 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG-TRGEASGWFPSAFVRL 232
           A A++   A +   L F  GD+I VL+  +  WW+G   G   GWFP ++V+ 
Sbjct: 2   ATALYPWRAKKENHLSFAKGDIITVLEQQE-MWWFGELEGGEEGWFPKSYVKE 53


>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 = 46.2 bits (110), Expect = 6e-07
 Identities = 19/50 (38%), Positives = 24/50 (48%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A  + D  A   EEL  R GDV+ +   LD+ W+ G      G FP  FV
Sbjct: 2   ARVLQDLSAQLDEELDLREGDVVTITGILDKGWFRGELNGRRGIFPEGFV 51


>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 = 46.2 bits (110), Expect = 6e-07
 Identities = 16/48 (33%), Positives = 25/48 (52%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A+ D VA +  +L F +GD + VL     DWWW       G+ P++ +
Sbjct: 4   AIADFVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGCCGYIPASHL 51


>gnl|CDD|215766 pfam00169, PH, PH domain.  PH stands for pleckstrin homology.
          Length = 101

 Score = 47.8 bits (114), Expect = 6e-07
 Identities = 23/105 (21%), Positives = 48/105 (45%), Gaps = 9/105 (8%)

Query: 485 LIHQGEVIRVTSGMWTNTIT--LFLFDHQLVYCKRDILKRNTHVYKARLNIDTSQIINLP 542
           +I +G +++  SG   +       LFD  L+Y K    K+++   K  + +   Q+  +P
Sbjct: 1   VIKEGWLLKKGSGGRKSWKKRYFVLFDGVLLYYKDS--KKSSSRPKGSIPLSGCQVTKVP 58

Query: 543 DGKDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLEDKARWLAAFQQ 587
           D +D       ++  +I   D++ +L     S E++  W+ A + 
Sbjct: 59  DSEDG----KRKNCFEIRTGDRETFL-LQAESEEERKEWVKAIRS 98


>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 = 46.1 bits (110), Expect = 7e-07
 Identities = 18/48 (37%), Positives = 28/48 (58%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D+ A   +EL F  GD++ + D  D +WW  T G  +G  PS +V
Sbjct: 4   ALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYV 51


>gnl|CDD|241397 cd13243, PH_PLEKHG1_G2_G3, Pleckstrin homology domain-containing
           family G members 1, 2, and 3 pleckstrin homology (PH)
           domain.  PLEKHG1 (also called ARHGEF41), PLEKHG2 (also
           called ARHGEF42 or CLG/common-site lymphoma/leukemia
           guanine nucleotide exchange factor2), and PLEKHG3 (also
           called ARHGEF43) have RhoGEF DH/double-homology domains
           in tandem with a PH domain which is involved in
           phospholipid binding. They function as a guanine
           nucleotide exchange factor (GEF) and are involved in the
           regulation of Rho protein signal transduction. Mutations
           in PLEKHG1 have been associated panic disorder (PD), an
           anxiety disorder characterized by panic attacks and
           anticipatory anxiety. PH domains have diverse functions,
           but in general are involved in targeting proteins to the
           appropriate cellular location or in the interaction with
           a binding partner. They share little sequence
           conservation, but all have a common fold, which is
           electrostatically polarized. Less than 10% of PH domains
           bind phosphoinositide phosphates (PIPs) with high
           affinity and specificity. PH domains are distinguished
           from other PIP-binding domains by their specific
           high-affinity binding to PIPs with two vicinal phosphate
           groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3
           which results in targeting some PH domain proteins to
           the plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.
          Length = 147

 Score = 48.5 bits (116), Expect = 9e-07
 Identities = 45/152 (29%), Positives = 67/152 (44%), Gaps = 19/152 (12%)

Query: 433 YVKITEALEAMRDVAMLINERKRRMESLEKLAAWQQRVEGWEGEDLIETSSQLIHQGEVI 492
           Y  + +A++ M  VA  IN+ KR+ E   +L   Q  ++GW G DL  T  +L+ +G   
Sbjct: 1   YEVVEDAIDTMTQVAWHINDMKRKHEHAVRLQEIQSLLDGWLGPDL-TTYGELVLEG-SF 58

Query: 493 RVTSGMWTNTITLFLFDHQLVYCKRDILKRNTHVYKARLNIDTSQII---NLPDGKDPHL 549
           RV  G   N   LFLFD  L+  K    KR       + +I  S ++   ++P  KDP L
Sbjct: 59  RV-QGA-KNERLLFLFDKMLLITK----KREDDHLVYKTHIMCSNLMLVESIP--KDP-L 109

Query: 550 GVTVRHAIKIHCSDKDKWLLFCCRSLEDKARW 581
              V        +          ++LE K  W
Sbjct: 110 SFQVLP-FDNPKAQ----YTLQAKNLEQKRLW 136


>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 = 45.6 bits (108), Expect = 1e-06
 Identities = 16/36 (44%), Positives = 22/36 (61%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           L F AG++I VL   D  WW G +    GWFP+++V
Sbjct: 17  LSFEAGELIRVLQAPDGGWWEGEKDGLRGWFPASYV 52


>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 = 45.4 bits (107), Expect = 1e-06
 Identities = 19/39 (48%), Positives = 23/39 (58%)

Query: 193 EELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           +EL F  GDVI V    +  WW GT    +GWFPS +VR
Sbjct: 14  DELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVR 52


>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 = 45.1 bits (107), Expect = 1e-06
 Identities = 19/53 (35%), Positives = 32/53 (60%), Gaps = 1/53 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS-GWFPSAFVRL 232
           A A++D+ A +  E+ F  GD+I  ++ +D  WW GT  + + G FP+ +V L
Sbjct: 2   ARALYDYQAADDTEISFDPGDIITDIEQIDEGWWRGTGPDGTYGLFPANYVEL 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 = 44.8 bits (106), Expect = 2e-06
 Identities = 20/52 (38%), Positives = 28/52 (53%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+A+ D    + +ELGFR  D+I ++   D   W G      GWFP+ FV L
Sbjct: 2   AKALLDFERHDDDELGFRKNDIITIISQKDEHCWVGELNGLRGWFPAKFVEL 53


>gnl|CDD|212769 cd11835, SH3_ARHGAP32_33, Src homology 3 domain of Rho
           GTPase-activating proteins 32 and 33, and similar
           proteins.  Members of this family contain N-terminal PX
           and Src Homology 3 (SH3) domains, a central Rho GAP
           domain, and C-terminal extensions. RhoGAPs (or ARHGAPs)
           bind to Rho proteins and enhance the hydrolysis rates of
           bound GTP. ARHGAP32 is also called RICS, PX-RICS,
           p250GAP, or p200RhoGAP. It is a Rho GTPase-activating
           protein for Cdc42 and Rac1, and is implicated in the
           regulation of postsynaptic signaling and neurite
           outgrowth. PX-RICS, a variant of RICS that contain PX
           and SH3 domains, is the main isoform expressed during
           neural development. It is involved in neural functions
           including axon and dendrite extension, postnatal
           remodeling, and fine-tuning of neural circuits during
           early brain development. ARHGAP33, also called sorting
           nexin 26 or TCGAP (Tc10/CDC42 GTPase-activating
           protein), is widely expressed in the brain where it is
           involved in regulating the outgrowth of axons and
           dendrites and is regulated by the protein tyrosine
           kinase Fyn. It is translocated to the plasma membrane in
           adipocytes in response to insulin and may be involved in
           the regulation of insulin-stimulated glucose transport.
           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 = 45.1 bits (107), Expect = 2e-06
 Identities = 17/54 (31%), Positives = 26/54 (48%), Gaps = 3/54 (5%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLD---TLDRDWWWGTRGEASGWFPSAFV 230
            A  +  + A   +EL    GD++ V+D     +  WW G +G   G+FPS  V
Sbjct: 1   AAHVIKRYTAQAPDELSLEVGDIVSVIDMPPPEESTWWRGKKGFQVGFFPSECV 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 = 45.0 bits (106), Expect = 2e-06
 Identities = 15/50 (30%), Positives = 28/50 (56%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           +  + ++    +EL  + GD+IEV+  ++  WW G     +G FPS F++
Sbjct: 3   QVAFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGVLNGKTGMFPSNFIK 52


>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 = 44.8 bits (106), Expect = 2e-06
 Identities = 20/54 (37%), Positives = 32/54 (59%), Gaps = 3/54 (5%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVRL 232
           A  ++D+   E  E+    G+++  ++ +D DWW GT  +GE SG FPS +V L
Sbjct: 2   AVVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMGTNSKGE-SGLFPSNYVEL 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 = 44.4 bits (105), Expect = 2e-06
 Identities = 19/49 (38%), Positives = 25/49 (51%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
           A A++D      E+L F+ GD I V + LD +W  G      G FP AF
Sbjct: 2   AVALYDFTGETEEDLSFQRGDRILVTEHLDAEWSRGRLNGREGIFPRAF 50


>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 = 44.4 bits (105), Expect = 3e-06
 Identities = 19/49 (38%), Positives = 25/49 (51%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
            A+  + A   E+LGFR GD I+VL  ++  W  G      G FP  FV
Sbjct: 3   VALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHSDGRVGIFPKCFV 51


>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 = 44.2 bits (104), Expect = 4e-06
 Identities = 17/50 (34%), Positives = 31/50 (62%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           + ++++V    +EL  + GD+I++ + ++  WW GT    SG FPS FV+
Sbjct: 4   KVLFEYVPQNEDELELKVGDIIDINEEVEEGWWSGTLNGKSGLFPSNFVK 53


>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 = 43.9 bits (104), Expect = 4e-06
 Identities = 17/49 (34%), Positives = 27/49 (55%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           +A++ + A   +EL  + GD+IEV +  D  WW G      G FP+ +V
Sbjct: 3   KALYSYTANREDELSLQPGDIIEVHEKQDDGWWLGELNGKKGIFPATYV 51


>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 = 43.6 bits (103), Expect = 5e-06
 Identities = 17/48 (35%), Positives = 25/48 (52%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++ + A + +EL F  GD+IE+L      WW G      G FP  +V
Sbjct: 4   ALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTGRLRGKEGLFPGNYV 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 = 43.5 bits (103), Expect = 6e-06
 Identities = 17/47 (36%), Positives = 26/47 (55%), Gaps = 3/47 (6%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVL---DTLDRDWWWGTRGEASGWFP 226
           A++D+ A   +EL FR GD + VL   D  + +WWW    +  G+ P
Sbjct: 5   ALFDYEAENGDELSFREGDELTVLRKGDDDETEWWWARLNDKEGYVP 51


>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 = 43.3 bits (102), Expect = 6e-06
 Identities = 23/52 (44%), Positives = 27/52 (51%), Gaps = 2/52 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
            +AV+        +LGF  GD+IEVL   D  WW G   R  A G FPS FV
Sbjct: 2   VKAVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLRRNGAEGIFPSNFV 53


>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 = 43.4 bits (103), Expect = 7e-06
 Identities = 19/52 (36%), Positives = 27/52 (51%), Gaps = 5/52 (9%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS-----GWFPSAF 229
           A++D       +L F+AGD+I VL+     WW G    +S     GWFPS +
Sbjct: 4   ALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKVKRGWFPSNY 55


>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 = 43.1 bits (102), Expect = 9e-06
 Identities = 15/50 (30%), Positives = 31/50 (62%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A+A++++   E  +L F+ GD+I +   +D +W+ G      G+FP+++V
Sbjct: 2   AKALYNYEGKEPGDLSFKKGDIILLRKRIDENWYHGECNGKQGFFPASYV 51


>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 = 42.3 bits (99), Expect = 2e-05
 Identities = 17/39 (43%), Positives = 22/39 (56%)

Query: 193 EELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           +EL    GD+I V    +  WW GT    +GWFPS +VR
Sbjct: 16  DELSVCKGDIIYVTRVEEGGWWEGTLNGKTGWFPSNYVR 54


>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 = 42.2 bits (99), Expect = 2e-05
 Identities = 17/49 (34%), Positives = 29/49 (59%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           A++  +  E  +L  + GD + V+D  + DWW G  G+  G+FP+ FV+
Sbjct: 4   ALYKFLPQENNDLPLQPGDRVMVVDDSNEDWWKGKSGDRVGFFPANFVQ 52


>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 = 42.4 bits (100), Expect = 2e-05
 Identities = 17/39 (43%), Positives = 21/39 (53%), Gaps = 2/39 (5%)

Query: 194 ELGFRAGDVIEVLDTLDR--DWWWGTRGEASGWFPSAFV 230
           +L F+AGD I VL   D   DWW G      G FP+ +V
Sbjct: 15  DLSFQAGDRITVLTRTDSQFDWWEGRLRGRVGIFPANYV 53


>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 = 41.7 bits (98), Expect = 2e-05
 Identities = 18/47 (38%), Positives = 28/47 (59%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
           A+  HVA ++ +L FR GD++ V+  +D DW   TRG   G  P ++
Sbjct: 4   ALCHHVATDSGQLSFRKGDILRVIARVDDDWLLCTRGSTKGLVPLSY 50


>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 = 42.1 bits (99), Expect = 2e-05
 Identities = 19/51 (37%), Positives = 28/51 (54%), Gaps = 2/51 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFV 230
             ++D+  +  +EL  + GDVIEV+  +T D  WW G      G+FP  FV
Sbjct: 3   RVLFDYNPVAPDELALKKGDVIEVISKETEDEGWWEGELNGRRGFFPDNFV 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 = 41.9 bits (99), Expect = 2e-05
 Identities = 17/48 (35%), Positives = 27/48 (56%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D+ A + +EL F+ GD+I V    D  W+ G     +G FP  +V
Sbjct: 4   ALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYV 51


>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 = 41.7 bits (98), Expect = 2e-05
 Identities = 19/49 (38%), Positives = 28/49 (57%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
           A A++D      +EL F+AGD+I  L+++D +W  G     SG FP  F
Sbjct: 2   ARALYDFTGENEDELSFKAGDIITELESIDEEWMSGELRGKSGIFPKNF 50


>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 = 41.9 bits (99), Expect = 2e-05
 Identities = 19/54 (35%), Positives = 28/54 (51%), Gaps = 4/54 (7%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR---GEASGWFPSAFVR 231
            + V  + A + +EL    GDV+ VL  +   W+ G R   GE  GWFPS++  
Sbjct: 2   VQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGERLRDGE-RGWFPSSYTE 54


>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 = 41.8 bits (98), Expect = 2e-05
 Identities = 20/53 (37%), Positives = 31/53 (58%), Gaps = 5/53 (9%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAFV 230
           A+A +D  A +  EL  + GDV+++ +   +  WW  RGE +   GWFPS +V
Sbjct: 2   AKARYDFCARDMRELSLKEGDVVKIYNKKGQQGWW--RGEINGRIGWFPSTYV 52


>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 = 41.8 bits (98), Expect = 2e-05
 Identities = 19/49 (38%), Positives = 28/49 (57%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           +A+  H+A E  +L F  GD+++VL   D DW   + G  SG  P A+V
Sbjct: 3   KALCHHIATEPGQLSFNKGDILQVLSRADGDWLRCSLGPDSGLVPIAYV 51


>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 = 41.3 bits (97), Expect = 3e-05
 Identities = 16/48 (33%), Positives = 24/48 (50%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A  D+ A   E+L F  GD I++L  ++++W  G      G FP  F 
Sbjct: 4   AQHDYSAQGPEDLEFSQGDTIDILSEVNQEWLEGHCDGRIGIFPKCFA 51


>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 = 41.6 bits (98), Expect = 3e-05
 Identities = 20/55 (36%), Positives = 27/55 (49%), Gaps = 4/55 (7%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVL----DTLDRDWWWGTRGEASGWFPSAFV 230
           L  A++D+ A   EEL F  G +I +L    + +D  WW G      G FPS  V
Sbjct: 1   LVRALYDYEAQSDEELSFPEGAIIRILRKDDNGVDDGWWEGEFNGRVGVFPSLVV 55


>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 = 41.3 bits (97), Expect = 3e-05
 Identities = 14/47 (29%), Positives = 27/47 (57%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
            V D+   +  E+  RAGDV++V++  +  WW+ +  +  GW P+ +
Sbjct: 4   VVADYKKQQPNEISLRAGDVVDVIEKNENGWWFVSLEDEQGWVPATY 50


>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 = 41.5 bits (98), Expect = 3e-05
 Identities = 17/50 (34%), Positives = 28/50 (56%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
             A++D       ELGF+ GD+I + + +D +W+ G     SG+FP  +V
Sbjct: 3   CRALYDFEPENEGELGFKEGDIITLTNQIDENWYEGMVNGQSGFFPVNYV 52


>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 = 41.1 bits (97), Expect = 3e-05
 Identities = 17/50 (34%), Positives = 24/50 (48%), Gaps = 3/50 (6%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAF 229
           A++D  A   +EL F  G++I V    D +WW G         G FP +F
Sbjct: 4   ALYDCQADNDDELTFSEGEIIVVTGEEDDEWWEGHIEGDPSRRGVFPVSF 53


>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 = 41.5 bits (97), Expect = 3e-05
 Identities = 18/50 (36%), Positives = 30/50 (60%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A AV+D  A  ++EL F+ GD + +L  +D++W+ G      G FP ++V
Sbjct: 3   ARAVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGEHHGRVGIFPISYV 52


>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 = 41.3 bits (97), Expect = 4e-05
 Identities = 22/54 (40%), Positives = 29/54 (53%), Gaps = 5/54 (9%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVL--DTL---DRDWWWGTRGEASGWFPSAFVR 231
           AV+D+ A   +EL  R GD +EVL  D+    D  WW G   +  G FPS +V 
Sbjct: 4   AVFDYEASAEDELTLRRGDRVEVLSKDSAVSGDEGWWTGKINDRVGIFPSNYVT 57


>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 = 41.5 bits (97), Expect = 4e-05
 Identities = 19/52 (36%), Positives = 28/52 (53%), Gaps = 2/52 (3%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+WD+ A   +EL F+ GD++ VL  D    DWWW +     G+ P  +  L
Sbjct: 5   ALWDYSAEFPDELSFKEGDMVTVLRKDGEGTDWWWASLCGREGYVPRNYFGL 56


>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 = 41.3 bits (97), Expect = 4e-05
 Identities = 17/49 (34%), Positives = 30/49 (61%), Gaps = 1/49 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEA-SGWFPSAFV 230
           A++D+ A  ++EL    GD+I VL   + +WW+G+      G+FP+ +V
Sbjct: 4   ALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFGSLVNGQQGYFPANYV 52


>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 = 41.2 bits (97), Expect = 4e-05
 Identities = 19/51 (37%), Positives = 26/51 (50%), Gaps = 3/51 (5%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLD---TLDRDWWWGTRGEASGWFPSAFV 230
           AV  ++  +   L F  GDVI++L     LD  W +GT    SG FP  +V
Sbjct: 4   AVRAYITRDQTLLSFHKGDVIKLLPKEGPLDPGWLFGTLDGRSGAFPKEYV 54


>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 = 40.9 bits (96), Expect = 4e-05
 Identities = 17/52 (32%), Positives = 29/52 (55%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A A++D+ A + +E+ F   D+I  ++ +D  WW G      G FP+ +V L
Sbjct: 2   AVALYDYQAADDDEISFDPDDIITNIEMIDEGWWRGVCRGKYGLFPANYVEL 53


>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 = 41.2 bits (96), Expect = 5e-05
 Identities = 20/39 (51%), Positives = 27/39 (69%), Gaps = 2/39 (5%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWW 215
           VLA+A++D+VA   +EL FR GD++ VL  DT   D WW
Sbjct: 3   VLAKALYDNVAESPDELSFRKGDIMTVLERDTQGLDGWW 41


>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 = 40.7 bits (96), Expect = 5e-05
 Identities = 18/50 (36%), Positives = 25/50 (50%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A   +++ A   +EL  R GD + VL+     WW G      GWFPS +V
Sbjct: 2   AVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYV 51


>gnl|CDD|212955 cd12022, SH3_p47phox_2, Second or C-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 second SH3 domain (or C-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 = 40.6 bits (95), Expect = 6e-05
 Identities = 17/45 (37%), Positives = 27/45 (60%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
            + A+E +EL    G+ IEV+  L   WW   +GE +G+FPS ++
Sbjct: 7   AYTAVEEDELTLLEGEAIEVIHKLLDGWWVVRKGEVTGYFPSMYL 51


>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 = 40.6 bits (95), Expect = 6e-05
 Identities = 20/53 (37%), Positives = 27/53 (50%), Gaps = 5/53 (9%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTL-----DRDWWWGTRGEASGWFPSAFV 230
           A++D+ A   +EL  R G  +EVL        D  WW G  G+  G FPS +V
Sbjct: 4   ALFDYDARGEDELTLRRGQPVEVLSKDAAVSGDEGWWTGKIGDKVGIFPSNYV 56


>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 = 40.4 bits (95), Expect = 7e-05
 Identities = 16/58 (27%), Positives = 26/58 (44%), Gaps = 5/58 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEA--SGWFPSAFVRL 232
           +A+ +    A    +L    G ++ V       WW G    RG+    GWFP+ +V+L
Sbjct: 1   IAQVIAPFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQARGKKRQIGWFPANYVKL 58


>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 = 40.3 bits (94), Expect = 8e-05
 Identities = 16/52 (30%), Positives = 31/52 (59%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+A++++   E  +L F  GD+I +   +D +W+ G      G+FP+ FV++
Sbjct: 3   AKALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGEVNGIHGFFPTNFVQI 54


>gnl|CDD|212957 cd12024, SH3_NoxO1_2, Second or C-terminal Src homology 3 domain of
           NADPH oxidase (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 second SH3 domain
           (or C-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 = 53

 Score = 40.0 bits (94), Expect = 9e-05
 Identities = 15/46 (32%), Positives = 24/46 (52%)

Query: 187 HVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           + A + +EL   AG V+EVL   D  WW       +G+ PS +++ 
Sbjct: 8   YEAQKEDELSVPAGVVVEVLQKSDNGWWLIRYNGRAGYVPSMYLQP 53


>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 = 9e-05
 Identities = 20/54 (37%), Positives = 33/54 (61%), Gaps = 2/54 (3%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGD-VIEVLDTLDRDWWWG-TRGEASGWFPSAFV 230
           V   AV+D+   E +EL F+AG+ +++V D  ++ W  G T G A G +P+ +V
Sbjct: 2   VRVRAVYDYTGQEPDELSFKAGEELLKVEDEDEQGWCKGVTDGGAVGLYPANYV 55


>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 = 40.1 bits (94), Expect = 9e-05
 Identities = 18/51 (35%), Positives = 28/51 (54%), Gaps = 1/51 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWW-GTRGEASGWFPSAFV 230
           A+A++D+     EEL F  GD ++V D  D DW   G  G   G+ P+ ++
Sbjct: 2   AKALYDYDKQTEEELSFNEGDTLDVYDDSDSDWILVGFNGTQFGFVPANYI 52


>gnl|CDD|212891 cd11958, SH3_RUSC1, Src homology 3 domain of RUN and SH3
           domain-containing protein 1.  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. 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 = 51

 Score = 39.8 bits (93), Expect = 1e-04
 Identities = 18/44 (40%), Positives = 25/44 (56%), Gaps = 1/44 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFP 226
           A+ DH   E  +L FR G+ ++VL T+D DW    RG+  G  P
Sbjct: 4   ALCDHAGSE-SQLSFRKGEELQVLGTVDEDWIRCRRGDREGLVP 46


>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 = 39.9 bits (93), Expect = 1e-04
 Identities = 16/46 (34%), Positives = 24/46 (52%), Gaps = 2/46 (4%)

Query: 189 AMEAEELGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFVRL 232
           A   +EL  + GD++ ++  D +D  WW G      G FP  FV+L
Sbjct: 10  AQNEDELTIKEGDIVTLISKDCIDAGWWEGELNGRRGVFPDNFVKL 55


>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 = 40.2 bits (94), Expect = 1e-04
 Identities = 18/49 (36%), Positives = 23/49 (46%), Gaps = 2/49 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR-GEASGWFPSAFV 230
           A+WD  A   EEL F+AGD   + +    DWW   +   A G     FV
Sbjct: 4   ALWDFKARGDEELSFQAGDQFRIAER-SGDWWTALKLDRAGGVVAQGFV 51


>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 = 40.1 bits (93), Expect = 1e-04
 Identities = 20/52 (38%), Positives = 29/52 (55%), Gaps = 1/52 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+A++   A +   L F   DVI VL+  D  WW+G      GWFP ++V+L
Sbjct: 2   AQALYPWRAKKDNHLNFNKNDVITVLEQQDM-WWFGEVQGQKGWFPKSYVKL 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 = 40.0 bits (93), Expect = 1e-04
 Identities = 19/52 (36%), Positives = 27/52 (51%), Gaps = 2/52 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTL--DRDWWWGTRGEASGWFPSAFV 230
           A A ++  A +  EL  R GDV+ +   +  D+ WW G      GWFPS +V
Sbjct: 3   AVARYNFAARDMRELSLREGDVVRIYSRIGGDQGWWKGETNGRIGWFPSTYV 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 = 40.0 bits (93), Expect = 1e-04
 Identities = 17/51 (33%), Positives = 30/51 (58%), Gaps = 2/51 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
            A++D+ A + +E+ F+ GD I  + T+D  W +GT  R   +G  P+ +V
Sbjct: 5   RAMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQRTGKTGMLPANYV 55


>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 = 39.6 bits (93), Expect = 1e-04
 Identities = 16/50 (32%), Positives = 29/50 (58%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A A++   A  A+EL  + GD+I +   +D++W+ G      G FP+++V
Sbjct: 2   ARALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGEHNGRVGIFPASYV 51


>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 = 39.3 bits (92), Expect = 2e-04
 Identities = 15/45 (33%), Positives = 23/45 (51%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPS 227
           AV  +   E  E+    GD ++VL   +  +W G+    +GWFPS
Sbjct: 4   AVKSYSPQEEGEISLHKGDRVKVLSIGEGGFWEGSVRGRTGWFPS 48


>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 = 39.3 bits (91), Expect = 2e-04
 Identities = 18/53 (33%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
            A+A+    A +   L F   D+I VL+    +WW+G      GWFP ++V+L
Sbjct: 1   KAQALCSWTAKKDNHLNFSKNDIITVLEQ-QENWWFGEVHGGRGWFPKSYVKL 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 = 39.3 bits (92), Expect = 2e-04
 Identities = 17/38 (44%), Positives = 25/38 (65%), Gaps = 2/38 (5%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWW 215
           LA A++D+VA   +EL FR GD++ VL  +T   + WW
Sbjct: 1   LARALYDNVAESPDELAFRRGDILTVLEQNTAGLEGWW 38


>gnl|CDD|212952 cd12019, SH3_Tks5_4, Fourth 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 fourth 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 = 53

 Score = 39.2 bits (91), Expect = 2e-04
 Identities = 16/39 (41%), Positives = 23/39 (58%)

Query: 194 ELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           E+ F AG  +EVL+  +  WW+   GE  GW PS ++ L
Sbjct: 15  EISFPAGVEVEVLEKQESGWWYVRFGELEGWAPSHYLEL 53


>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 = 39.2 bits (91), Expect = 2e-04
 Identities = 16/52 (30%), Positives = 29/52 (55%), Gaps = 2/52 (3%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVRL 232
           A++D+ A + +E+ FR GD I  +  +D  W +GT  R   +G  P+ ++  
Sbjct: 5   AMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVQRTGRTGMLPANYIEF 56


>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 = 38.8 bits (91), Expect = 3e-04
 Identities = 19/52 (36%), Positives = 31/52 (59%), Gaps = 2/52 (3%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVRL 232
           A++D+ A + +E+ F+ GDVI  ++ +D  W  GT  R   SG  P+ +V L
Sbjct: 4   AMYDYAAADDDEVSFQEGDVIINVEIIDDGWMEGTVQRTGQSGMLPANYVEL 55


>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 = 38.5 bits (90), Expect = 3e-04
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDR--DWWWGTRGEASGWFPSAFV 230
           A++   A   +E+ F+ GD+I+V ++      W  G     +GWFP+ +V
Sbjct: 4   ALYAFEARNPDEISFQPGDIIQVDESQVAEPGWLAGELKGKTGWFPANYV 53


>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 = 38.8 bits (90), Expect = 3e-04
 Identities = 20/53 (37%), Positives = 31/53 (58%), Gaps = 5/53 (9%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAFV 230
           A+A +D  A +  EL  + GD+I++L+   +  WW  RGE     GWFP+ +V
Sbjct: 2   AKARYDFCARDRSELSLKEGDIIKILNKKGQQGWW--RGEIYGRVGWFPANYV 52


>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 = 38.4 bits (90), Expect = 4e-04
 Identities = 23/57 (40%), Positives = 29/57 (50%), Gaps = 7/57 (12%)

Query: 181 AEAVWD-HVAMEAEELGFRAGDVIEVL---DTLDRD--WWWG-TRGEASGWFPSAFV 230
             A++D        EL  + GD++ VL   D L RD  WW G TR    GWFPS +V
Sbjct: 2   CRALYDFTPENPEMELSLKKGDIVAVLSKTDPLGRDSEWWKGRTRDGRIGWFPSNYV 58


>gnl|CDD|212713 cd11779, SH3_Irsp53_BAIAP2L, Src Homology 3 domain of Insulin
           Receptor tyrosine kinase Substrate p53, Brain-specific
           Angiogenesis Inhibitor 1-Associated Protein 2
           (BAIAP2)-Like proteins, and similar proteins.  Proteins
           in this family include IRSp53, BAIAP2L1, BAIAP2L2, and
           similar proteins. They all contain an
           Inverse-Bin/Amphiphysin/Rvs (I-BAR) or IMD domain in
           addition to the SH3 domain. IRSp53, also known as
           BAIAP2, is a scaffolding protein that takes part in many
           signaling pathways including Cdc42-induced filopodia
           formation, Rac-mediated lamellipodia extension, and
           spine morphogenesis. IRSp53 exists as multiple splicing
           variants that differ mainly at the C-termini. BAIAP2L1,
           also called IRTKS (Insulin Receptor Tyrosine Kinase
           Substrate), serves as a substrate for the insulin
           receptor and binds the small GTPase Rac. It plays a role
           in regulating the actin cytoskeleton and colocalizes
           with F-actin, cortactin, VASP, and vinculin. IRSp53 and
           IRTKS also mediate the recruitment of effector proteins
           Tir and EspFu, which regulate host cell actin
           reorganization, to bacterial attachment sites. BAIAP2L2
           co-localizes with clathrin plaques but its function has
           not been determined. The SH3 domains of IRSp53 and IRTKS
           have been shown to bind the proline-rich C-terminus of
           EspFu. 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 = 38.5 bits (90), Expect = 4e-04
 Identities = 20/53 (37%), Positives = 27/53 (50%), Gaps = 3/53 (5%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRD-WWWGT--RGEASGWFPSAFVR 231
           +A++ H A    +L F  GDVI +L    RD W +G   R    GWFP A+  
Sbjct: 4   KALYPHAAGGETQLSFEEGDVITLLGPEPRDGWHYGENERSGRRGWFPIAYTE 56


>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 = 38.1 bits (88), Expect = 5e-04
 Identities = 20/54 (37%), Positives = 30/54 (55%), Gaps = 5/54 (9%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASG---WFPSAFV 230
           +A A +D  A +  EL    GDV+++   +  + WW  RGE +G   WFPS +V
Sbjct: 2   IAIARYDFCARDMRELSLLKGDVVKIYTKMSTNGWW--RGEVNGRVGWFPSTYV 53


>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 = 38.2 bits (89), Expect = 5e-04
 Identities = 15/53 (28%), Positives = 23/53 (43%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
            A A +D+      EL F+ GD + +   +  DWW G      G  P  ++ L
Sbjct: 1   EATAQFDYTGRSERELSFKKGDSLTLYRQVSDDWWRGQLNGQDGLVPHKYITL 53


>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 = 37.7 bits (88), Expect = 6e-04
 Identities = 14/51 (27%), Positives = 24/51 (47%), Gaps = 1/51 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDT-LDRDWWWGTRGEASGWFPSAFV 230
           A A  D  A   +EL F+ G +++VL+   D +W+        G  P  ++
Sbjct: 2   AVAKHDFKATAEDELSFKKGSILKVLNMEDDPNWYKAELDGKEGLIPKNYI 52


>gnl|CDD|212849 cd11916, SH3_Sorbs1_3, Third (or C-terminal) 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 = 59

 Score = 38.0 bits (88), Expect = 6e-04
 Identities = 17/53 (32%), Positives = 31/53 (58%), Gaps = 2/53 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVRL 232
           +A++ +     +EL  R GD+++V++  D  W+ GT  R +  G FP  +V+L
Sbjct: 5   QALYSYAPQNDDELELRDGDIVDVMEKCDDGWFVGTSRRTKQFGTFPGNYVKL 57


>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 = 37.4 bits (87), Expect = 7e-04
 Identities = 11/36 (30%), Positives = 19/36 (52%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           + F+ G  +EV+D     WW+       GW PS+++
Sbjct: 16  ISFQKGQKVEVIDKNPSGWWYVKIDGKEGWAPSSYI 51


>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 = 37.7 bits (87), Expect = 8e-04
 Identities = 18/54 (33%), Positives = 32/54 (59%), Gaps = 4/54 (7%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFV 230
           L  A++D+ A   ++L F  G+  ++L++ + DWW     T GE +G+ PS +V
Sbjct: 2   LFVALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGE-TGYIPSNYV 54


>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 = 37.6 bits (87), Expect = 8e-04
 Identities = 20/55 (36%), Positives = 27/55 (49%), Gaps = 4/55 (7%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVL----DTLDRDWWWGTRGEASGWFPSAFV 230
           LA A++ +     EEL F  G +I +L    D +D  +W G  G   G FPS  V
Sbjct: 1   LARALYSYTGQSPEELSFPEGALIRLLPRAQDGVDDGFWRGEFGGRVGVFPSLLV 55


>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 = 37.6 bits (87), Expect = 9e-04
 Identities = 17/39 (43%), Positives = 22/39 (56%), Gaps = 2/39 (5%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDR--DWWW 215
            LA+A++D+ A   EEL FR GDV+ VL         WW
Sbjct: 1   QLAKALYDNAAESPEELSFRRGDVLMVLKREHGSLPGWW 39


>gnl|CDD|212729 cd11795, SH3_DNMBP_N2, Second 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 = 54

 Score = 37.0 bits (86), Expect = 0.001
 Identities = 15/47 (31%), Positives = 25/47 (53%), Gaps = 1/47 (2%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTLDRDWWWG-TRGEASGWFPSAFVR 231
              + E   L  + GD++E+  T D  W  G +   +SG+FPS+ V+
Sbjct: 7   AFTSQEPGHLNLQRGDLVELTGTTDSGWLQGRSCWGSSGFFPSSCVQ 53


>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 = 37.2 bits (86), Expect = 0.001
 Identities = 20/52 (38%), Positives = 31/52 (59%), Gaps = 3/52 (5%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG-TRGEAS--GWFPSAFV 230
           +A+++ VA   +EL F  G++I V    D++WW G   GE +  G FP +FV
Sbjct: 3   KALYNCVADNPDELTFSEGEIIIVDGEEDKEWWIGHIDGEPTRRGAFPVSFV 54


>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 = 37.1 bits (86), Expect = 0.001
 Identities = 18/46 (39%), Positives = 25/46 (54%), Gaps = 3/46 (6%)

Query: 178 VVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASG 223
            V A A +D+    A+EL F+ GDV+ +      DWW   RGE +G
Sbjct: 1   EVEAVACFDYTGRTAQELSFKRGDVLLLHSKASSDWW---RGEHNG 43


>gnl|CDD|241231 cd00821, PH, Pleckstrin homology (PH) domain.  PH domains have
           diverse functions, but in general are involved in
           targeting proteins to the appropriate cellular location
           or in the interaction with a binding partner. They share
           little sequence conservation, but all have a common
           fold, which is electrostatically polarized. Less than
           10% of PH domains bind phosphoinositide phosphates
           (PIPs) with high affinity and specificity. PH domains
           are distinguished from other PIP-binding domains by
           their specific high-affinity binding to PIPs with two
           vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2
           or PtdIns(3,4,5)P3 which results in targeting some PH
           domain proteins to the plasma membrane. A few display
           strong specificity in lipid binding. Any specificity is
           usually determined by loop regions or insertions in the
           N-terminus of the domain, which are not conserved across
           all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinase,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, as well as cytoskeletal associated
           molecules and in lipid associated enzymes.
          Length = 92

 Score = 38.1 bits (88), Expect = 0.001
 Identities = 16/100 (16%), Positives = 32/100 (32%), Gaps = 10/100 (10%)

Query: 487 HQGEVIRVTSGMWTNTIT--LFLFDHQLVYCKRDILKRNTHVYKARLNIDTSQIINLPDG 544
            +G + +       +       LFD  L+Y K     +     K +  I  S  + +   
Sbjct: 1   KEGWLKKRGGKGLKSWKKRWFVLFDDVLLYYK----SKKDSSKKPKGLIPLSDGLEVELV 56

Query: 545 KDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLEDKARWLAA 584
                     +  ++   D+ +       S E++  WL A
Sbjct: 57  SSS----GKPNCFELVTPDRGRTYYLQAESEEEREEWLEA 92


>gnl|CDD|213007 cd12074, SH3_Tks5_1, First 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 first 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 = 53

 Score = 37.0 bits (85), Expect = 0.001
 Identities = 12/40 (30%), Positives = 25/40 (62%)

Query: 191 EAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           E  E+  +AG+V++V++  +  WW+ +  E  GW P+ ++
Sbjct: 12  ENSEISLQAGEVVDVIEKNESGWWFVSTAEEQGWVPATYL 51


>gnl|CDD|212872 cd11939, SH3_ephexin1, Src homology 3 domain of the Rho guanine
           nucleotide exchange factor, ephexin-1 (also called NGEF
           or ARHGEF27).  Ephexin-1, also called NGEF (neuronal
           GEF) or ARHGEF27, activates RhoA, Tac1, and Cdc42 by
           exchanging bound GDP for free GTP. It is expressed
           mainly in the brain in a region associated with movement
           control. It regulates the stability of postsynaptic
           acetylcholine receptor (AChR) clusters and thus, plays a
           critical role in the maturation and neurotransmission of
           neuromuscular junctions. Ephexin-1 directly interacts
           with the ephrin receptor EphA4 and their coexpression
           enhances the ability of ephexin-1 to activate RhoA. It
           is required for normal axon growth and EphA-induced
           growth cone collapse. Ephexin-1 contains 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 = 36.8 bits (85), Expect = 0.001
 Identities = 19/51 (37%), Positives = 28/51 (54%), Gaps = 2/51 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR--GEASGWFPSAFV 230
           + V  +V+ E +EL     DV+ +LD  D  W +G R   +  GWFPS+ V
Sbjct: 3   QCVHPYVSQEPDELSLELADVLNILDKTDDGWIFGERLHDQERGWFPSSVV 53


>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 = 36.9 bits (85), Expect = 0.002
 Identities = 20/51 (39%), Positives = 30/51 (58%), Gaps = 7/51 (13%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLD--TLDRDWWW-----GTRGEASG 223
           +A A++D+V   AEEL FR GD++ V++  T   + WW     G +G A G
Sbjct: 1   MARALYDNVPECAEELAFRKGDILTVIEQNTGGLEGWWLCSLHGRQGIAPG 51


>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 = 36.9 bits (85), Expect = 0.002
 Identities = 15/48 (31%), Positives = 26/48 (54%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D+   + +EL F+ G +I V+   D  W+ G     +G FP  +V
Sbjct: 7   AIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGVTGLFPGNYV 54


>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 = 36.5 bits (84), Expect = 0.002
 Identities = 16/49 (32%), Positives = 25/49 (51%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           A+ D+       L F  GD + VLDT   +WW+       G+ PS++V+
Sbjct: 4   AIKDYCPTNFTTLKFSKGDHLYVLDTSGGEWWYAHNTTEMGYIPSSYVQ 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 = 36.6 bits (85), Expect = 0.002
 Identities = 14/50 (28%), Positives = 24/50 (48%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
              ++D+ A E +EL    GDV+ V++  +  WW   R    G  P  ++
Sbjct: 2   YSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTVERNGQKGLVPGTYL 51


>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 = 36.5 bits (85), Expect = 0.002
 Identities = 20/58 (34%), Positives = 30/58 (51%), Gaps = 5/58 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEV----LDTLDRDWWWGTR-GEASGWFPSAFVRL 232
           +A A +D VA   +EL FRAGD + +    L    R W   T  G+  G  P+ +V++
Sbjct: 1   VARAEYDFVAESEDELSFRAGDKLRLAPKELQPRVRGWLLATVDGQKIGLVPANYVKI 58


>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 = 36.2 bits (84), Expect = 0.002
 Identities = 17/47 (36%), Positives = 23/47 (48%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
           A++   A+E  EL F  GD I ++ TL+  W  G      G FP  F
Sbjct: 4   ALYRFQALEPNELDFEVGDRIRIIATLEDGWLEGELKGRRGIFPHRF 50


>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 = 36.5 bits (84), Expect = 0.002
 Identities = 17/49 (34%), Positives = 28/49 (57%), Gaps = 1/49 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           A++ + + E  +L F  G+ I V    D +WW G+  + +G FPS +VR
Sbjct: 4   ALYPYSSSEPGDLTFNEGEEILVTQK-DGEWWTGSIEDRTGIFPSNYVR 51


>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 = 36.4 bits (84), Expect = 0.002
 Identities = 17/47 (36%), Positives = 22/47 (46%)

Query: 185 WDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           +D+ A   +EL    GD+I  +   D  WW G      G FP  FVR
Sbjct: 6   FDYKAQHEDELTITVGDIITKIKKDDGGWWEGEIKGRRGLFPDNFVR 52


>gnl|CDD|212850 cd11917, SH3_Sorbs2_3, Third (or C-terminal) 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 = 61

 Score = 36.5 bits (84), Expect = 0.002
 Identities = 18/52 (34%), Positives = 32/52 (61%), Gaps = 2/52 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVR 231
           +A+++++    +EL  R GDVI+V++  D  W+ GT  R +  G FP  +V+
Sbjct: 8   QALYNYMPRNEDELELREGDVIDVMEKCDDGWFVGTSRRTKFFGTFPGNYVK 59


>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 = 36.5 bits (84), Expect = 0.002
 Identities = 16/47 (34%), Positives = 24/47 (51%), Gaps = 3/47 (6%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRD---WWWGTRGEASGWFP 226
           A+WD+     +EL F+ GD + +L   D D   WWW    +  G+ P
Sbjct: 5   ALWDYEGESDDELSFKEGDCMTILRREDEDETEWWWARLNDKEGYVP 51


>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 = 36.2 bits (84), Expect = 0.002
 Identities = 19/54 (35%), Positives = 27/54 (50%), Gaps = 2/54 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFVRL 232
           A  ++D+ A   +EL  R GD++ +L  D  D+ WW G      G FP  FV  
Sbjct: 2   ARVLFDYEAENEDELTLREGDIVTILSKDCEDKGWWKGELNGKRGVFPDNFVEP 55


>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 = 36.2 bits (84), Expect = 0.002
 Identities = 18/54 (33%), Positives = 28/54 (51%), Gaps = 4/54 (7%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWW---GTRGEASGWFPSAFV 230
              A++D  +  + EL  RAG+V+ +      D W     +RGE  G FPS++V
Sbjct: 1   KVRALYDFDSQPSGELSLRAGEVLTITRQDVGDGWLEGRNSRGE-VGLFPSSYV 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 = 36.2 bits (83), Expect = 0.002
 Identities = 15/48 (31%), Positives = 25/48 (52%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A++D+   + +EL F  G +I V+   D  W+ G     +G FP  +V
Sbjct: 4   AIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVCNGVTGLFPGNYV 51


>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 = 36.3 bits (84), Expect = 0.003
 Identities = 16/50 (32%), Positives = 26/50 (52%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFV 230
           A++ +     +EL F+ G++I ++  DT +  WW G      G FP  FV
Sbjct: 6   ALFHYEGTNEDELDFKEGEIILIISKDTGEPGWWKGELNGKEGVFPDNFV 55


>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 = 36.2 bits (84), Expect = 0.003
 Identities = 13/52 (25%), Positives = 25/52 (48%), Gaps = 2/52 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR--GEASGWFPSAFV 230
            +A++D     A EL  +  D++ ++   D  WW   +      GW P+A++
Sbjct: 2   YKALYDFAGSVANELSLKKDDIVYIVQKEDNGWWLAKKLDESKEGWVPAAYL 53


>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 = 35.8 bits (83), Expect = 0.003
 Identities = 19/50 (38%), Positives = 27/50 (54%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A A ++  A    EL FR GDVI +   +D +W+ G  G   G FP ++V
Sbjct: 2   ARAKYNFNADTGVELSFRKGDVITLTRRVDENWYEGRIGGRQGIFPVSYV 51


>gnl|CDD|212847 cd11914, SH3_BAIAP2L2, Src Homology 3 domain of Brain-specific
           Angiogenesis Inhibitor 1-Associated Protein 2-Like 2.
           BAIAP2L2 co-localizes with clathrin plaques but its
           function has not been determined. It contains an
           N-terminal IMD or Inverse-Bin/Amphiphysin/Rvs (I-BAR)
           domain, an SH3 domain, and a WASP homology 2 (WH2)
           actin-binding motif at the C-terminus. The related
           proteins, BAIAP2L1 and IRSp53, function as regulators of
           membrane dynamics and the actin cytoskeleton. 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 = 35.9 bits (83), Expect = 0.003
 Identities = 17/40 (42%), Positives = 22/40 (55%), Gaps = 3/40 (7%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAFVR 231
           L F  GD+I VL    R+ W   + E S   GWFP A+V+
Sbjct: 18  LRFNRGDIITVLVPEARNGWLYGKLEGSSRQGWFPEAYVK 57


>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 = 36.2 bits (83), Expect = 0.003
 Identities = 15/51 (29%), Positives = 30/51 (58%), Gaps = 4/51 (7%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFV 230
           A++D+ A   E+L F+ G+  ++++  + DWW       G+ +G+ PS +V
Sbjct: 5   ALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGK-NGYIPSNYV 54


>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 = 36.1 bits (83), Expect = 0.003
 Identities = 19/58 (32%), Positives = 29/58 (50%), Gaps = 5/58 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEA--SGWFPSAFVRL 232
           +A+    +VA   E+L    G +I +L      WW G    RG+    GWFP++ V+L
Sbjct: 1   IAQVTTAYVASGVEQLSLSPGQLILILKKNSSGWWLGELQARGKKRQKGWFPASHVKL 58


>gnl|CDD|213012 cd12079, SH3_Tks5_3, Third 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 third 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 = 35.8 bits (82), Expect = 0.003
 Identities = 13/39 (33%), Positives = 22/39 (56%)

Query: 192 AEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           ++ + FR G   EV++     WW+   GE  GW PS+++
Sbjct: 14  SDGISFRGGQKAEVIEKNSGGWWYVQIGEKEGWAPSSYI 52


>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 = 35.8 bits (83), Expect = 0.004
 Identities = 16/53 (30%), Positives = 26/53 (49%), Gaps = 5/53 (9%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT----RGEA-SGWFPSAFV 230
           A++ + +   ++L F  G +I V +  D DW++G      G    G FP  FV
Sbjct: 6   ALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYVDSNGNTKEGIFPKNFV 58


>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 = 35.2 bits (81), Expect = 0.004
 Identities = 18/51 (35%), Positives = 28/51 (54%), Gaps = 5/51 (9%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAF 229
           EA++D+ A   +E+  R GD I V+   D   W  T GE +   G FP+++
Sbjct: 3   EALYDYEAQGDDEISIRVGDRIAVIRGDDGSGW--TYGEINGVKGLFPTSY 51


>gnl|CDD|213008 cd12075, SH3_Tks4_1, First 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 first 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 = 55

 Score = 35.4 bits (81), Expect = 0.005
 Identities = 12/53 (22%), Positives = 29/53 (54%), Gaps = 4/53 (7%)

Query: 175 EDFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPS 227
           + +VV+A    ++   E+ E+    G V+++++  +  WW+ +  +  GW P+
Sbjct: 1   DQYVVVA----NYQKQESSEISLYVGQVVDIIEKNESGWWFVSTADEQGWVPA 49


>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 = 35.3 bits (82), Expect = 0.005
 Identities = 18/56 (32%), Positives = 29/56 (51%), Gaps = 4/56 (7%)

Query: 176 DFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           + +V     +D+ A E +EL  + GD+I  +  ++  WW GT     G FP  FV+
Sbjct: 1   EVIVE----FDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTLNGKRGMFPDNFVK 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 = 35.2 bits (81), Expect = 0.005
 Identities = 12/46 (26%), Positives = 27/46 (58%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           D  A  +++L   +G+++ +L+ +D +W+ G     +G FP+  V+
Sbjct: 7   DFPAEHSDDLSLNSGEIVYLLEKIDTEWYRGKCKNTTGIFPANHVK 52


>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 = 35.2 bits (81), Expect = 0.005
 Identities = 13/50 (26%), Positives = 30/50 (60%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
            A++D+      E+  + GD++ +L++ ++DWW     +  G+ P+A+V+
Sbjct: 3   VALYDYQEKSPREVSMKKGDILTLLNSSNKDWWKVEVNDRQGFVPAAYVK 52


>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 = 34.9 bits (81), Expect = 0.006
 Identities = 15/51 (29%), Positives = 23/51 (45%), Gaps = 3/51 (5%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWW--WGTRGEASGWFPSAFVR 231
           A++D   +E  +L    G+   VLD  +  WW      G   G+ PS +V 
Sbjct: 4   ALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRARDKNGN-EGYIPSNYVT 53


>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 = 34.9 bits (80), Expect = 0.006
 Identities = 21/56 (37%), Positives = 29/56 (51%), Gaps = 5/56 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLD-----TLDRDWWWGTRGEASGWFPSAFV 230
           L  A++D+ A   +EL  R GDV+EVL      + D  WW G      G FP+ +V
Sbjct: 1   LWTALYDYEASGEDELSLRRGDVVEVLSQDAAVSGDDGWWAGKIRHRLGIFPANYV 56


>gnl|CDD|241257 cd01223, PH_Vav, Vav pleckstrin homology (PH) domain.  Vav acts as
           a guanosine nucleotide exchange factor (GEF) for Rho/Rac
           proteins. They control processes including T cell
           activation, phagocytosis, and migration of cells. The
           Vav subgroup of Dbl GEFs consists of three family
           members (Vav1, Vav2, and Vav3) in mammals. Vav1 is
           preferentially expressed in the hematopoietic system,
           while Vav2 and Vav3 are described by broader expression
           patterns. Mammalian Vav proteins consist of a calponin
           homology (CH) domain, an acidic region, a catalytic Dbl
           homology (DH) domain, a PH domain, a zinc finger
           cysteine rich domain (C1/CRD), and an SH2 domain,
           flanked by two SH3 domains. In invertebrates such as
           Drosophila and C. elegans, Vav is missing the N-terminal
           SH3 domain. The DH domain is involved in RhoGTPase
           recognition and selectivity and stimulates the
           reorganization of the switch regions for GDP/GTP
           exchange. The PH domain is implicated in directing
           membrane localization, allosteric regulation of guanine
           nucleotide exchange activity, and as a phospholipid-
           dependent regulator of GEF activity. Vavs bind
           RhoGTPases including Rac1, RhoA, RhoG, and Cdc42, while
           other members of the GEF family are specific for a
           single RhoGTPase. This promiscuity is thought to be a
           result of its CRD. PH domains have diverse functions,
           but in general are involved in targeting proteins to the
           appropriate cellular location or in the interaction with
           a binding partner. They share little sequence
           conservation, but all have a common fold, which is
           electrostatically polarized. Less than 10% of PH domains
           bind phosphoinositide phosphates (PIPs) with high
           affinity and specificity. PH domains are distinguished
           from other PIP-binding domains by their specific
           high-affinity binding to PIPs with two vicinal phosphate
           groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3
           which results in targeting some PH domain proteins to
           the plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.polarized. PH domains also have
           diverse functions. They are often involved in targeting
           proteins to the plasma membrane, but only a few (less
           than 10%) display strong specificity in binding inositol
           phosphates. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinases, tyrosine kinases,
           regulators of G-proteins, endocytotic GTPases, adaptors,
           cytoskeletal associated molecules, and in lipid
           associated enzymes.
          Length = 127

 Score = 36.8 bits (86), Expect = 0.006
 Identities = 22/83 (26%), Positives = 38/83 (45%), Gaps = 6/83 (7%)

Query: 506 FLFDHQLVYCKRDILKRNTHVYKARLNIDTSQIINLPDGKDPHLGVTVRHAIKIHCSDKD 565
           FLFD  L+ CKR  L+ + + YK  +N+   +I + P  +   L    R + +     K 
Sbjct: 41  FLFDKVLLVCKR--LRGDQYEYKEIINLSEYKIEDDPSRRT--LKRDKRWSYQFLLVHKQ 96

Query: 566 KW--LLFCCRSLEDKARWLAAFQ 586
                    ++ E K +W+ AF+
Sbjct: 97  GKTAYTLYAKTEELKKKWMEAFE 119


>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 = 35.0 bits (80), Expect = 0.007
 Identities = 17/50 (34%), Positives = 29/50 (58%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
           AV+D+ A + +E+ F+ GD I  +  +D  W +GT  R   +G  P+ +V
Sbjct: 7   AVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGTVERTGDTGMLPANYV 56


>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 = 35.0 bits (80), Expect = 0.007
 Identities = 14/46 (30%), Positives = 23/46 (50%)

Query: 185 WDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           +++ A   +EL    G  + V++     WW G+     GWFPS +V
Sbjct: 8   FNYTAEREDELSLVKGTKVIVMEKCSDGWWRGSYNGQVGWFPSNYV 53


>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 = 34.5 bits (79), Expect = 0.008
 Identities = 13/48 (27%), Positives = 26/48 (54%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A+ D+      E+  + GDV+EV++  +  WW+       GW P++++
Sbjct: 4   AIADYEKSSKSEMALKTGDVVEVVEKSENGWWFCQLKAKRGWVPASYL 51


>gnl|CDD|212877 cd11944, SH3_Endophilin_B2, Src homology 3 domain of Endophilin-B2.
            Endophilin-B2, also called SH3GLB2 (SH3-domain
           GRB2-like endophilin B2), is a cytoplasmic protein that
           interacts with the apoptosis inducer Bax. It is
           overexpressed in prostate cancer metastasis and has been
           identified as a cancer antigen with potential utility in
           immunotherapy. Endophilins play roles in synaptic
           vesicle formation, virus budding, mitochondrial
           morphology maintenance, receptor-mediated endocytosis
           inhibition, and endosomal sorting. They 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. Endophilin-B2 forms homo- and heterodimers (with
           endophilin-B1) through its BAR domain. The related
           protein endophilin-B1 interacts with amphiphysin 1 and
           dynamin 1 through its 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 = 34.6 bits (79), Expect = 0.008
 Identities = 18/54 (33%), Positives = 28/54 (51%), Gaps = 2/54 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEV--LDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A  ++D+ A ++ EL   A ++I V  L  +D DW  G RG   G  P  ++ L
Sbjct: 2   ARVLYDYEAADSSELALLADELITVYSLPGMDPDWLIGERGNQKGKVPVTYLEL 55


>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 = 34.7 bits (80), Expect = 0.008
 Identities = 16/49 (32%), Positives = 29/49 (59%), Gaps = 1/49 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS-GWFPSAFV 230
           A++D+   E++EL F+AGD++  L+  D   W   R +   G +P+ +V
Sbjct: 4   ALYDYEGQESDELSFKAGDILTKLEEEDEQGWCKGRLDGRVGLYPANYV 52


>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 = 34.6 bits (79), Expect = 0.009
 Identities = 15/44 (34%), Positives = 22/44 (50%)

Query: 187 HVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           +VA   +EL    G  + V++     WW G+     GWFPS +V
Sbjct: 9   YVAEREDELSLVKGSRVTVMEKCSDGWWRGSYNGQIGWFPSNYV 52


>gnl|CDD|212851 cd11918, SH3_Vinexin_3, Third (or C-terminal) 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 = 58

 Score = 34.5 bits (79), Expect = 0.009
 Identities = 16/50 (32%), Positives = 25/50 (50%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
           AV+ +     +EL  R GD ++V+   D  W+ G   R +  G FP  +V
Sbjct: 6   AVYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYV 55


>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 = 34.4 bits (79), Expect = 0.010
 Identities = 16/50 (32%), Positives = 25/50 (50%), Gaps = 1/50 (2%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A   +D  A   +EL F+ GDV+++L + D  W+        G+ P  FV
Sbjct: 2   ARGKFDFTASGEDELSFKKGDVLKILSS-DDIWFKAELNGEEGYVPKNFV 50


>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 = 34.2 bits (79), Expect = 0.011
 Identities = 16/49 (32%), Positives = 26/49 (53%), Gaps = 1/49 (2%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRG-EASGWFPSAFV 230
           A++D+ A   +EL F    +I  ++  D  WW G  G +   WFP+ +V
Sbjct: 4   ALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGKKQKWFPANYV 52


>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 = 34.1 bits (78), Expect = 0.013
 Identities = 17/52 (32%), Positives = 28/52 (53%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A+A+ ++      +L F  GDVI +   LD +W+ G     SG FP++ V +
Sbjct: 3   AKALCNYRGHNPGDLKFNKGDVILLRRQLDENWYLGEINGVSGIFPASSVEV 54


>gnl|CDD|212921 cd11988, SH3_Intersectin2_1, First Src homology 3 domain (or SH3A)
           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 first SH3 domain (or
           SH3A) of ITSN2 is expected to bind many protein
           partners, similar to ITSN1 which has been shown to bind
           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 = 57

 Score = 34.1 bits (78), Expect = 0.014
 Identities = 16/50 (32%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRD--WWWGTRGEASGWFPSAFV 230
           A++   A   +E+ F AGD+I+V +    +  W +G+     GWFP  +V
Sbjct: 6   ALYPFEARNHDEMSFNAGDIIQVDEKTVGEPGWLYGSFQGNFGWFPCNYV 55


>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 = 33.9 bits (78), Expect = 0.015
 Identities = 14/50 (28%), Positives = 26/50 (52%), Gaps = 4/50 (8%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEA--SGWFPSAFV 230
           A +D+ A   +EL  +  + + +LD  D   WW  +  +  +G+ PS +V
Sbjct: 4   AKYDYTAQGDQELSIKKNEKLTLLD--DSKHWWKVQNSSNQTGYVPSNYV 51


>gnl|CDD|213001 cd12068, SH3_MYO15B, Src Homology 3 domain of Myosin XVb.  Myosin
           XVb, also called KIAA1783, was named based on its
           similarity with myosin XVa. It is a transcribed and
           unprocessed pseudogene whose predicted amino acid
           sequence contains mutated or deleted amino acid residues
           that are normally conserved and important for myosin
           function. The related myosin XVa is important for normal
           growth of mechanosensory stereocilia of inner ear hair
           cells. 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 = 55

 Score = 34.1 bits (78), Expect = 0.016
 Identities = 15/40 (37%), Positives = 23/40 (57%), Gaps = 2/40 (5%)

Query: 195 LGFRAGDVIEVL--DTLDRDWWWGTRGEASGWFPSAFVRL 232
           L F  GD+I++L    L+  W +G+ G  SG FP+  V+ 
Sbjct: 16  LSFHRGDLIKLLPMAGLEPGWQFGSTGGRSGLFPADIVQP 55


>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 = 34.2 bits (78), Expect = 0.016
 Identities = 17/55 (30%), Positives = 29/55 (52%), Gaps = 1/55 (1%)

Query: 177 FVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT-RGEASGWFPSAFV 230
           F    +A++D+ A   +EL F    +I+ ++  +  WW G   G+   WFPS +V
Sbjct: 2   FKCAVKALFDYKAQREDELTFTKNAIIQNVEKQEGGWWRGDYGGKKQLWFPSNYV 56


>gnl|CDD|212946 cd12013, SH3_RIM-BP_3, Third 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 = 61

 Score = 33.9 bits (78), Expect = 0.018
 Identities = 18/44 (40%), Positives = 26/44 (59%), Gaps = 2/44 (4%)

Query: 190 MEAE-ELGFRAGDVIEVLDTLDRD-WWWGTRGEASGWFPSAFVR 231
           ++AE EL FRAGD+I V   +D D +++G      G  PS F+ 
Sbjct: 17  VDAEVELSFRAGDIITVFGEMDEDGFYYGELNGQRGLVPSNFLE 60


>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 = 33.5 bits (76), Expect = 0.020
 Identities = 14/51 (27%), Positives = 31/51 (60%), Gaps = 4/51 (7%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFV 230
           A++D+ +    +L F+ G+ +++++  + DWW     T G+ +G+ PS +V
Sbjct: 4   ALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQ-TGYIPSNYV 53


>gnl|CDD|212878 cd11945, SH3_Endophilin_B1, Src homology 3 domain of Endophilin-B1.
            Endophilin-B1, also called Bax-interacting factor 1
           (Bif-1) or SH3GLB1 (SH3-domain GRB2-like endophilin B1),
           is localized mainly to the Golgi apparatus. It is
           involved in the regulation of many biological events
           including autophagy, tumorigenesis, nerve growth factor
           (NGF) trafficking, neurite outgrowth, mitochondrial
           outer membrane dynamics, and cell death. Endophilins
           play roles in synaptic vesicle formation, virus budding,
           mitochondrial morphology maintenance, receptor-mediated
           endocytosis inhibition, and endosomal sorting. They
           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. Endophilin-B1 forms homo- and
           heterodimers (with endophilin-B2) through its BAR
           domain. It interacts with amphiphysin 1 and dynamin 1
           through its 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 = 33.8 bits (77), Expect = 0.021
 Identities = 18/54 (33%), Positives = 26/54 (48%), Gaps = 2/54 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDT--LDRDWWWGTRGEASGWFPSAFVRL 232
           A  ++D+ A  + EL   A +VI V     +D DW  G RG   G  P  ++ L
Sbjct: 6   ARVLYDYDAANSTELSLLADEVITVYSVPGMDSDWLMGERGNQKGKVPITYLEL 59


>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 = 33.8 bits (77), Expect = 0.021
 Identities = 19/54 (35%), Positives = 29/54 (53%), Gaps = 3/54 (5%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFVRL 232
           + ++D  A   +EL F  G+VI V    D++WW G    + E  G FP +FV +
Sbjct: 3   KTIYDCQADNDDELTFVEGEVIIVTGEEDQEWWIGHIEGQPERKGVFPVSFVHI 56


>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 = 33.7 bits (77), Expect = 0.022
 Identities = 14/36 (38%), Positives = 20/36 (55%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           L F+  D+I V+  +D +W  G  G+  G FP  FV
Sbjct: 22  LKFQKDDIITVISRVDENWAEGKLGDQVGIFPILFV 57


>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 = 33.5 bits (77), Expect = 0.024
 Identities = 18/53 (33%), Positives = 29/53 (54%), Gaps = 3/53 (5%)

Query: 180 LAEAVWDHVAMEAEE---LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAF 229
             +A++D    + +E   L F+ GDVI V+  +D +W  G  G+  G FP +F
Sbjct: 1   QCKALYDFEMKDEDEKDCLTFKKGDVITVIRRVDENWAEGRLGDKIGIFPISF 53


>gnl|CDD|212694 cd11760, SH3_MIA_like, Src Homology 3 domain of Melanoma Inhibitory
           Activity protein and similar proteins.  MIA is a single
           domain protein that adopts a SH3 domain-like fold; it
           contains an additional antiparallel beta sheet and two
           disulfide bonds compared to classical SH3 domains. MIA
           is secreted from malignant melanoma cells and it plays
           an important role in melanoma development and invasion.
           MIA is expressed by chondrocytes in normal tissues and
           may be important in the cartilage cell phenotype. Unlike
           classical SH3 domains, MIA does not bind proline-rich
           ligands. MIA is a member of the recently identified
           family that also includes MIA-like (MIAL), MIA2, and
           MIA3 (also called TANGO); the biological functions of
           this family are not yet fully understood.
          Length = 76

 Score = 34.0 bits (78), Expect = 0.025
 Identities = 17/58 (29%), Positives = 26/58 (44%), Gaps = 6/58 (10%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDW---WWGTRGEAS---GWFPSAFVR 231
            A A+ D+   +   L F+ GD I V   L  +    W G+ G  +   G+FP   V+
Sbjct: 13  RARALEDYHGPDCRFLNFKKGDTIYVYSKLAGERQDLWAGSVGGDAGLFGYFPKNLVQ 70


>gnl|CDD|212871 cd11938, SH3_ARHGEF16_26, Src homology 3 domain of the Rho guanine
           nucleotide exchange factors ARHGEF16 and ARHGEF26.
           ARHGEF16, also called ephexin-4, acts as a GEF for RhoG,
           activating it by exchanging bound GDP for free GTP. RhoG
           is a small GTPase that is a crucial regulator of Rac in
           migrating cells. ARHGEF16 interacts directly with the
           ephrin receptor EphA2 and mediates cell migration and
           invasion in breast cancer cells by activating RhoG.
           ARHGEF26, also called SGEF (SH3 domain-containing
           guanine exchange factor), also activates RhoG. It is
           highly expressed in liver and may play a role in
           regulating membrane dynamics. ARHGEF16 and ARHGEF26
           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 = 33.3 bits (76), Expect = 0.026
 Identities = 19/53 (35%), Positives = 29/53 (54%), Gaps = 4/53 (7%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR---GEASGWFPSAFVR 231
           E +  + A + +EL  +  DV+ VL T    W++G R   GE  GWFPS+  +
Sbjct: 3   EIIKAYTAKQPDELSLQQADVVLVLQTESDGWYYGERLRDGE-RGWFPSSCAK 54


>gnl|CDD|212846 cd11913, SH3_BAIAP2L1, Src Homology 3 domain of Brain-specific
           Angiogenesis Inhibitor 1-Associated Protein 2-Like 1,
           also called Insulin Receptor Tyrosine Kinase Substrate
           (IRTKS).  BAIAP2L1 or IRTKS is widely expressed, serves
           as a substrate for the insulin receptor, and binds the
           small GTPase Rac. It plays a role in regulating the
           actin cytoskeleton and colocalizes with F-actin,
           cortactin, VASP, and vinculin. BAIAP2L1 expression leads
           to the formation of short actin bundles, distinct from
           filopodia-like protrusions induced by the expression of
           the related protein IRSp53. IRTKS mediates the
           recruitment of effector proteins Tir and EspFu, which
           regulate host cell actin reorganization, to bacterial
           attachment sites. It contains an N-terminal IMD or
           Inverse-Bin/Amphiphysin/Rvs (I-BAR) domain, an SH3
           domain, and a WASP homology 2 (WH2) actin-binding motif
           at the C-terminus. The SH3 domain of IRTKS has been
           shown to bind the proline-rich C-terminus of EspFu. 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 = 33.4 bits (76), Expect = 0.027
 Identities = 17/41 (41%), Positives = 24/41 (58%), Gaps = 3/41 (7%)

Query: 195 LGFRAGDVIEVLDTLDRD-WWWGTR--GEASGWFPSAFVRL 232
           L F  GDVI +L   ++D W +G     +A GWFPS++ R 
Sbjct: 18  LSFAQGDVITLLIPEEKDGWLYGEHDTTKARGWFPSSYTRP 58


>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 = 33.3 bits (76), Expect = 0.029
 Identities = 15/54 (27%), Positives = 32/54 (59%), Gaps = 3/54 (5%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFVRL 232
           A A++   A E++EL F+ GD++++L+  D   W+    +G   G+ P  ++++
Sbjct: 2   AVALYSFQATESDELPFQKGDILKILNMEDDQNWYKAELQGR-EGYIPKNYIKV 54


>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 = 33.4 bits (76), Expect = 0.030
 Identities = 16/42 (38%), Positives = 22/42 (52%), Gaps = 6/42 (14%)

Query: 192 AEELGFRAGDVIEVLDTLDRDWWWGTR------GEASGWFPS 227
           ++ L FR GDV+ V+D  D +WW   R       E  G+ PS
Sbjct: 20  SQALSFRFGDVLHVIDAGDEEWWQARRVHSDSETEEIGFIPS 61


>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 = 33.0 bits (76), Expect = 0.030
 Identities = 15/53 (28%), Positives = 23/53 (43%), Gaps = 1/53 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIE-VLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A A++   A +  EL F  G +I  V  + +  W  GT    +G  P  +V  
Sbjct: 2   ARALYACKAEDESELSFEPGQIITNVQPSDEPGWLEGTLNGRTGLIPENYVEF 54


>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 = 32.9 bits (75), Expect = 0.031
 Identities = 16/50 (32%), Positives = 26/50 (52%), Gaps = 1/50 (2%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGE-ASGWFPSAFV 230
           +A++D+ A  ++EL F  G +I  +      WW G  G     +FPS +V
Sbjct: 3   KALYDYRAKRSDELSFCKGALIHNVSKETGGWWKGDYGGKVQHYFPSNYV 52


>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 = 0.033
 Identities = 18/58 (31%), Positives = 24/58 (41%), Gaps = 7/58 (12%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRD-----WWWGTR--GEASGWFPSAFVR 231
             A  D+ A + +EL F  GDVI V+   D +     W  G +      G FP  F  
Sbjct: 5   VRATHDYTAEDTDELTFEKGDVILVIPFDDPEEQDEGWLMGVKESTGCRGVFPENFTE 62


>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 = 32.6 bits (75), Expect = 0.037
 Identities = 18/51 (35%), Positives = 27/51 (52%), Gaps = 2/51 (3%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEV--LDTLDRDWWWGTRGEASGWFPSAF 229
           A  ++D+ A ++ EL   A +VI V  L  +D D+  G RG   G  P A+
Sbjct: 2   ARVLYDYDAEDSTELSLLADEVITVYELPGMDEDYMMGERGSQRGKVPVAY 52


>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 = 33.0 bits (75), Expect = 0.038
 Identities = 16/51 (31%), Positives = 25/51 (49%), Gaps = 2/51 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDT-LDR-DWWWGTRGEASGWFPSAFV 230
           + +WD    + +EL F+ GD I +L    +R  WW G      G  P A++
Sbjct: 3   QGLWDCTGDQPDELSFKRGDTIYILSKEYNRFGWWVGEMKGTIGLVPKAYI 53


>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 = 32.8 bits (75), Expect = 0.039
 Identities = 15/52 (28%), Positives = 24/52 (46%), Gaps = 6/52 (11%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVL----DTLDRDWWWGTRGEASGWFPSAFV 230
            +WD    E +EL F+ GD+I ++    D+    WW G      G  P  ++
Sbjct: 4   GLWDCSGNEPDELSFKRGDLIYIISKEYDSF--GWWVGELNGKVGLVPKDYL 53


>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 = 32.8 bits (74), Expect = 0.040
 Identities = 19/58 (32%), Positives = 33/58 (56%), Gaps = 6/58 (10%)

Query: 175 EDFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEA--SGWFPSAFV 230
           E+ +V+A+  WD+ A + +EL  +  + + +LD  D   WW  R  A  +G+ PS +V
Sbjct: 2   EEVIVIAK--WDYTAQQDQELDIKKNERLWLLD--DSKTWWRVRNAANRTGYVPSNYV 55


>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 = 32.4 bits (74), Expect = 0.044
 Identities = 16/48 (33%), Positives = 23/48 (47%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A +D    + +EL F  GDVI + + +  +W  G      G FP  FV
Sbjct: 4   ARFDFEGEQEDELSFSEGDVITLKEYVGEEWAKGELNGKIGIFPLNFV 51


>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 = 32.6 bits (74), Expect = 0.047
 Identities = 12/51 (23%), Positives = 28/51 (54%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           +A++ +   E  +L F  GD+I +   +D +W+ G      G+ P+++++ 
Sbjct: 4   KALYSYEGKEPGDLKFNKGDIIILRRKVDENWYHGELNGCHGFLPASYIQC 54


>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 = 32.7 bits (75), Expect = 0.047
 Identities = 12/52 (23%), Positives = 26/52 (50%), Gaps = 1/52 (1%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS-GWFPSAFVRL 232
           EA+ D  A +  +L F+ G+V+ ++      WW     + + G  P  ++++
Sbjct: 3   EALSDFQAEQEGDLSFKKGEVLRIISKRADGWWLAENSKGNRGLVPKTYLKV 54


>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 = 32.6 bits (74), Expect = 0.048
 Identities = 15/52 (28%), Positives = 28/52 (53%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A A +D  A   +EL  + GD++ +   +D++W+ G      G FP +++ L
Sbjct: 3   ARAKFDFKAQTLKELPLQKGDIVYIYKQIDQNWYEGEHHGRVGIFPRSYIEL 54


>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 = 32.7 bits (74), Expect = 0.048
 Identities = 11/39 (28%), Positives = 21/39 (53%)

Query: 193 EELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
           +E+GF  G  +EV+      WW+       GW P+++++
Sbjct: 15  DEIGFEKGVTVEVIQKNLEGWWYIRYLGKEGWAPASYLK 53


>gnl|CDD|212825 cd11892, SH3_MIA2, Src Homology 3 domain of Melanoma Inhibitory
           Activity 2 protein.  MIA2 is expressed specifically in
           hepatocytes and its expression is controlled by
           hepatocyte nuclear factor 1 binding sites in the MIA2
           promoter. It inhibits the growth and invasion of
           hepatocellular carcinomas (HCC) and may act as a tumor
           suppressor. A mutation in MIA2 in mice resulted in
           reduced cholesterol and triglycerides. Since MIA2
           localizes to ER exit sites, it may function as an
           ER-to-Golgi trafficking protein that regulates lipid
           metabolism. MIA2 contains an N-terminal SH3-like domain,
           similar to MIA. It is a member of the recently
           identified family that also includes MIA, MIAL, and MIA3
           (also called TANGO). MIA is a single domain protein that
           adopts a SH3 domain-like fold; it contains an additional
           antiparallel beta sheet and two disulfide bonds compared
           to classical SH3 domains. Unlike classical SH3 domains,
           MIA does not bind proline-rich ligands.
          Length = 73

 Score = 32.9 bits (75), Expect = 0.049
 Identities = 16/49 (32%), Positives = 24/49 (48%), Gaps = 3/49 (6%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDR---DWWWGTRGEASGWFP 226
            +A+ D+   +   L F+ GD I V   L     D W G+ G+  G+FP
Sbjct: 14  VQAIRDYRGPDCRYLSFKKGDEIIVYYKLSGKREDLWAGSTGKEFGYFP 62


>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 = 32.4 bits (74), Expect = 0.065
 Identities = 11/39 (28%), Positives = 20/39 (51%), Gaps = 1/39 (2%)

Query: 180 LAEAVWDHVAM-EAEELGFRAGDVIEVLDTLDRDWWWGT 217
              A+  +  + + +EL F+ GD+  V + L+  W W T
Sbjct: 3   RVRAILPYNKVPDTDELSFQKGDIFVVHNELEDGWLWVT 41


>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 = 31.9 bits (73), Expect = 0.065
 Identities = 15/51 (29%), Positives = 27/51 (52%), Gaps = 3/51 (5%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR--GEASGWFPSAFVR 231
           A++D  + E   L F  G+   +L+  +  WW  T   GE +G+ P+ +V+
Sbjct: 4   ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLVTNHSGE-TGYVPANYVK 53


>gnl|CDD|212765 cd11831, SH3_VAV_1, First 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 = 62

 Score = 32.2 bits (73), Expect = 0.069
 Identities = 15/40 (37%), Positives = 22/40 (55%), Gaps = 3/40 (7%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAFVR 231
           L  + GDV+E+L       WW  R  A+   G+FPS+ V+
Sbjct: 22  LTLQTGDVVELLKGDAESPWWEGRNVATREVGYFPSSSVK 61


>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 = 32.0 bits (73), Expect = 0.070
 Identities = 19/56 (33%), Positives = 32/56 (57%), Gaps = 6/56 (10%)

Query: 181 AEAVWDHVAM--EAEELGFRAGDVIEVLDTLDRDWWWGTR--GEASGWFPSAFVRL 232
           A A++ + A   +  EL F  G+++EV DT  + WW   +  GE +G  PS +++L
Sbjct: 2   ARALYPYDASPDDPNELSFEKGEILEVSDTSGK-WWQARKSNGE-TGICPSNYLQL 55


>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 = 31.8 bits (73), Expect = 0.073
 Identities = 15/50 (30%), Positives = 22/50 (44%), Gaps = 4/50 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEA--SGWFPS 227
               ++D  A  ++EL    G+ +EVLD  D   WW  R      G+ P 
Sbjct: 1   YVRVLYDFTARNSKELSVLKGEYLEVLD--DSRQWWKVRNSRGQVGYVPH 48


>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 = 31.9 bits (73), Expect = 0.085
 Identities = 13/39 (33%), Positives = 18/39 (46%), Gaps = 1/39 (2%)

Query: 193 EELGFRAGDVIEVLDTLDRD-WWWGTRGEASGWFPSAFV 230
           EEL F+ G +I+V    D D ++ G      G  P   V
Sbjct: 22  EELPFKEGQLIKVYGDKDADGFYLGEINGRRGLVPCNMV 60


>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 = 31.8 bits (72), Expect = 0.094
 Identities = 17/40 (42%), Positives = 23/40 (57%), Gaps = 3/40 (7%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTR---GEASGWFPSAFVR 231
           L F+ GDVIE+L       WW  R    + SG+FPS+ V+
Sbjct: 20  LTFQTGDVIELLRGDPDSPWWEGRLLQTKKSGYFPSSSVK 59


>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 = 31.8 bits (73), Expect = 0.10
 Identities = 7/20 (35%), Positives = 15/20 (75%)

Query: 195 LGFRAGDVIEVLDTLDRDWW 214
           L F+ GD++++++  D +WW
Sbjct: 23  LSFKKGDILQIVNQDDPNWW 42


>gnl|CDD|212983 cd12050, SH3_DOCK2_A, Src Homology 3 domain of Class A Dedicator of
           Cytokinesis protein 2.  Dock2 is a hematopoietic
           cell-specific, class A DOCK and is an atypical guanine
           nucleotide exchange factor (GEF) that lacks the
           conventional Dbl homology (DH) domain. It plays an
           important role in lymphocyte migration and activation,
           T-cell differentiation, neutrophil chemotaxis, and type
           I interferon induction. All DOCKs contain two homology
           domains: the DHR-1 (Dock homology region-1), also called
           CZH1 (CED-5, Dock180, and MBC-zizimin homology 1), and
           DHR-2 (also called CZH2 or Docker). The DHR-1 domain
           binds phosphatidylinositol-3,4,5-triphosphate while
           DHR-2 contains the catalytic activity for Rac and/or
           Cdc42. Class A DOCKs also contain an SH3 domain at the
           N-terminal region and a PxxP motif at the C-terminus;
           they are specific GEFs for Rac. The SH3 domain of Dock2
           binds to DHR-2 in an autoinhibitory manner; binding of
           the scaffold protein Elmo to the SH3 domain of Dock2
           exposes the DHR-2 domain and promotes GEF 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 = 56

 Score = 31.4 bits (71), Expect = 0.12
 Identities = 13/54 (24%), Positives = 28/54 (51%), Gaps = 4/54 (7%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFVRLR 233
           A+++       +L  + GDV+ + +T + DW+ G      +  G FP +F+ ++
Sbjct: 4   AIYNFKGSGVPQLSLQIGDVVHIQETCE-DWYKGYLVRHKDLQGIFPKSFIHIK 56


>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 = 31.6 bits (72), Expect = 0.12
 Identities = 10/35 (28%), Positives = 21/35 (60%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWW 214
           + +A++D+     +EL  +  D++ +L+  D DWW
Sbjct: 1   VYKALYDYEPQTEDELTIQEDDILYLLEKSDDDWW 35


>gnl|CDD|212984 cd12051, SH3_DOCK1_5_A, Src Homology 3 domain of Class A Dedicator
           of Cytokinesis proteins 1 and 5.  Dock1, also called
           Dock180, and Dock5 are class A DOCKs and are atypical
           guanine nucleotide exchange factors (GEFs) that lack the
           conventional Dbl homology (DH) domain. Dock1 interacts
           with the scaffold protein Elmo and the resulting complex
           functions upstream of Rac in many biological events
           including phagocytosis of apoptotic cells, cell
           migration and invasion. Dock5 functions upstream of Rac1
           to regulate osteoclast function. All DOCKs contain two
           homology domains: the DHR-1 (Dock homology region-1),
           also called CZH1 (CED-5, Dock180, and MBC-zizimin
           homology 1), and DHR-2 (also called CZH2 or Docker). The
           DHR-1 domain binds
           phosphatidylinositol-3,4,5-triphosphate while DHR-2
           contains the catalytic activity for Rac and/or Cdc42.
           Class A DOCKs also contain an SH3 domain at the
           N-terminal region and a PxxP motif at the C-terminus;
           they are specific GEFs for Rac. The SH3 domain of Dock1
           binds to DHR-2 in an autoinhibitory manner; binding of
           Elmo to the SH3 domain of Dock1 exposes the DHR-2 domain
           and promotes GEF 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 = 56

 Score = 31.3 bits (71), Expect = 0.12
 Identities = 14/56 (25%), Positives = 31/56 (55%), Gaps = 4/56 (7%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFVRLR 233
             A++++ A   +EL  + GD + +L+T +  W+ G    +    G FP++++ L+
Sbjct: 2   GVAIYNYDARGPDELSLQIGDTVHILETYE-GWYRGYTLRKKSKKGIFPASYIHLK 56


>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 = 31.3 bits (71), Expect = 0.13
 Identities = 13/38 (34%), Positives = 21/38 (55%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASG 223
           DH   +  EL F  GD++ +++T +R  W+  R   SG
Sbjct: 9   DHTKPKPGELAFHKGDIVTIVETCERKGWYRARHNTSG 46


>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 = 31.6 bits (71), Expect = 0.13
 Identities = 17/58 (29%), Positives = 28/58 (48%), Gaps = 5/58 (8%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEAS--GWFPSAFVRL 232
           +A+ +  + A   E+L    G +I +       WW G    RG+    GWFP+ +V+L
Sbjct: 5   IAQVIASYTATGPEQLTLAPGQLILIRKKNPGGWWEGELQARGKKRQIGWFPANYVKL 62


>gnl|CDD|212848 cd11915, SH3_Irsp53, Src Homology 3 domain of Insulin Receptor
           tyrosine kinase Substrate p53.  IRSp53 is also known as
           BAIAP2 (Brain-specific Angiogenesis Inhibitor
           1-Associated Protein 2). It is a scaffolding protein
           that takes part in many signaling pathways including
           Cdc42-induced filopodia formation, Rac-mediated
           lamellipodia extension, and spine morphogenesis. IRSp53
           exists as multiple splicing variants that differ mainly
           at the C-termini. One variant (T-form) is expressed
           exclusively in human breast cancer cells. The gene
           encoding IRSp53 is a putative susceptibility gene for
           Gilles de la Tourette syndrome. IRSp53 can also mediate
           the recruitment of effector proteins Tir and EspFu,
           which regulate host cell actin reorganization, to
           bacterial attachment sites. It contains an N-terminal
           IMD, a CRIB (Cdc42 and Rac interactive binding motif),
           an SH3 domain, and a WASP homology 2 (WH2) actin-binding
           motif at the C-terminus. The SH3 domain of IRSp53 has
           been shown to bind the proline-rich C-terminus of EspFu.
           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 = 31.5 bits (71), Expect = 0.13
 Identities = 18/55 (32%), Positives = 28/55 (50%), Gaps = 4/55 (7%)

Query: 182 EAVWDHVAMEAEEL-GFRAGDVIEVLDTLDRDWWWGTRGEAS---GWFPSAFVRL 232
           +A++ H A +   L  F+ GD I +L    RD W     E +   GWFP ++ R+
Sbjct: 4   QAIFSHAAGDNSTLLSFKEGDYITLLVPEARDGWHYGECEKTKMRGWFPFSYTRV 58


>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 = 31.5 bits (71), Expect = 0.13
 Identities = 15/54 (27%), Positives = 30/54 (55%), Gaps = 1/54 (1%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLD-TLDRDWWWGTRGEASGWFPSAFVRLR 233
           A A +D  A   +EL F+ GD+++VL+   D++W+        G+ P  ++ ++
Sbjct: 3   AIAKYDFKATADDELSFKRGDILKVLNEECDQNWYKAELNGKDGFIPKNYIEMK 56


>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 = 30.8 bits (70), Expect = 0.17
 Identities = 9/32 (28%), Positives = 19/32 (59%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWW 214
           A++D    + E+L F+ G+++ V+   +  WW
Sbjct: 5   ALFDFPGNDDEDLPFKKGEILTVIRKPEEQWW 36


>gnl|CDD|213011 cd12078, SH3_Tks4_3, Third 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 third 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 = 53

 Score = 30.8 bits (69), Expect = 0.19
 Identities = 11/36 (30%), Positives = 20/36 (55%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           + F+AG  +EV++     WW+    +  GW P+ F+
Sbjct: 16  ISFQAGLKVEVIEKNLSGWWYIQIEDKEGWAPATFI 51


>gnl|CDD|241256 cd01221, PH_ephexin, Ephexin Pleckstrin homology (PH) domain.
           Ephexin-1 (also called NGEF/ neuronal guanine nucleotide
           exchange factor) plays a role in the homeostatic
           modulation of presynaptic neurotransmitter release.
           Specific functions are still unknown for Ephexin-2 (also
           called RhoGEF19) and Ephexin-3 (also called Rho guanine
           nucleotide exchange factor 5/RhoGEF5, Transforming
           immortalized mammary oncogene/p60 TIM, and
           NGEF/neuronalGEF). Ephexin-4 (also called RhoGEF16) acts
           downstream of EphA2 to promote ligand-independent breast
           cancer cell migration and invasion toward epidermal
           growth factor through activation of RhoG. This in turn
           results in the activation of RhoG which recruits ELMO2
           and Dock4 to form a complex with EphA2 at the tips of
           cortactin-rich protrusions in migrating breast cancer
           cells. Ephexin-5 is the specific GEF for RhoA activation
           and the regulation of vascular smooth muscle
           contractility. It interacts with EPHA4 PH domains have
           diverse functions, but in general are involved in
           targeting proteins to the appropriate cellular location
           or in the interaction with a binding partner. The
           members of the Ephexin family contains a RhoGEF (DH)
           followed by a PH domain and an SH3 domain. The ephexin
           PH domain is believed to act with the DH domain in
           mediating protein-protein interactions. PH domains have
           diverse functions, but in general are involved in
           targeting proteins to the appropriate cellular location
           or in the interaction with a binding partner. They share
           little sequence conservation, but all have a common
           fold, which is electrostatically polarized. Less than
           10% of PH domains bind phosphoinositide phosphates
           (PIPs) with high affinity and specificity. PH domains
           are distinguished from other PIP-binding domains by
           their specific high-affinity binding to PIPs with two
           vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2
           or PtdIns(3,4,5)P3 which results in targeting some PH
           domain proteins to the plasma membrane. A few display
           strong specificity in lipid binding. Any specificity is
           usually determined by loop regions or insertions in the
           N-terminus of the domain, which are not conserved across
           all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinase,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, as well as cytoskeletal associated
           molecules and in lipid associated enzymes.
          Length = 130

 Score = 32.6 bits (75), Expect = 0.20
 Identities = 26/135 (19%), Positives = 41/135 (30%), Gaps = 45/135 (33%)

Query: 478 LIETSSQLIHQGEV--IRVTSGMWT-------NTITLFLF-DHQLV-------------Y 514
           LI  S  L+ +GE+  +    G  T         + LFLF D  L+             Y
Sbjct: 7   LISQSRWLVKRGELTELVEDGGSLTFKKKKKKTPVYLFLFNDLLLITKKKSEERYTVLDY 66

Query: 515 CKRDILKRNTHVYKARLNIDTSQIINLPDGKDPHLGVTVRHAIKIH----CSDKDKWLLF 570
             R +L+                           L  + ++   +        K   LL 
Sbjct: 67  APRSLLQVEEV------------------EDPLPLQGSGKNLFLLTLLENHEGKTVELLL 108

Query: 571 CCRSLEDKARWLAAF 585
              S  D+ RW++A 
Sbjct: 109 SAESESDRERWISAL 123


>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 = 30.7 bits (69), Expect = 0.21
 Identities = 13/35 (37%), Positives = 22/35 (62%), Gaps = 2/35 (5%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWG--TRGEASGWFPS 227
           L FRAGD++++++  D +WW      G ++G  PS
Sbjct: 23  LKFRAGDLLQIVNQEDPNWWQACHVEGGSAGLIPS 57


>gnl|CDD|212785 cd11851, SH3_RIM-BP, Src homology 3 domains 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 = 30.7 bits (70), Expect = 0.22
 Identities = 18/43 (41%), Positives = 22/43 (51%), Gaps = 6/43 (13%)

Query: 192 AEELGFRAGDVIEVLDTLDRDWWWGTRGEAS----GWFPSAFV 230
            EEL F AGDV+ V   +D D ++   GE      G  PS FV
Sbjct: 20  EEELSFHAGDVVRVYGPMDEDGFY--YGELEGGRKGLVPSNFV 60


>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 = 30.6 bits (69), Expect = 0.24
 Identities = 16/51 (31%), Positives = 27/51 (52%), Gaps = 5/51 (9%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFV 230
           A +D V     +L  + G+ ++VL + D +WW     T G+  G+ PS +V
Sbjct: 4   AQYDFVPSNERDLQLKKGEKLQVLKS-DGEWWLAKSLTTGK-EGYIPSNYV 52


>gnl|CDD|241537 cd13386, PH1_FGD2, FYVE, RhoGEF and PH domain
           containing/faciogenital dysplasia protein 2 pleckstrin
           homology (PH), N-terminal domain.  In general, FGDs have
           a RhoGEF (DH) domain, followed by an N-terminal PH
           domain, a FYVE domain and a C-terminal PH domain. All
           FGDs are guanine nucleotide exchange factors that
           activates the Rho GTPase Cdc42, an important regulator
           of membrane trafficking. The RhoGEF domain is
           responsible for GEF catalytic activity, while the
           N-terminal PH domain is involved in intracellular
           targeting of the DH domain. Not much is known about
           FGD2.  FGD1 is the best characterized member of the
           group with mutations here leading to the X-linked
           disorder known as faciogenital dysplasia (FGDY). PH
           domains have diverse functions, but in general are
           involved in targeting proteins to the appropriate
           cellular location or in the interaction with a binding
           partner. They share little sequence conservation, but
           all have a common fold, which is electrostatically
           polarized. Less than 10% of PH domains bind
           phosphoinositide phosphates (PIPs) with high affinity
           and specificity. PH domains are distinguished from other
           PIP-binding domains by their specific high-affinity
           binding to PIPs with two vicinal phosphate groups:
           PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which
           results in targeting some PH domain proteins to the
           plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.
          Length = 107

 Score = 31.9 bits (72), Expect = 0.28
 Identities = 24/84 (28%), Positives = 40/84 (47%), Gaps = 12/84 (14%)

Query: 505 LFLFDHQLVYCKRDILKRNTHVYKARLNIDTS--QIINLPDGKDPHLGVTVRHAIKIHCS 562
           LFLF++ L+YC   +++     ++ R  ID +  ++  L D + PH  +          S
Sbjct: 21  LFLFNNMLLYCVPKVIQVGAE-FQVRTRIDVAGMKVRELMDAEFPHSFLV---------S 70

Query: 563 DKDKWLLFCCRSLEDKARWLAAFQ 586
            K + L    RS E+   W+ AFQ
Sbjct: 71  GKQRTLELQARSQEEMIAWIKAFQ 94


>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 = 30.7 bits (69), Expect = 0.28
 Identities = 13/37 (35%), Positives = 23/37 (62%), Gaps = 4/37 (10%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWG----TRGEASGWFPS 227
           L F+ GD+I++++  D +WW G    +  E++G  PS
Sbjct: 23  LKFQTGDIIQIINKDDSNWWQGRVEGSGEESAGLIPS 59


>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 = 30.3 bits (68), Expect = 0.28
 Identities = 15/50 (30%), Positives = 22/50 (44%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           A A +D+V   A EL F+ G  + +      DWW G      G  P  ++
Sbjct: 2   AIAKFDYVGRSARELSFKKGASLLLYHRASDDWWEGRHNGIDGLVPHQYI 51


>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 = 30.2 bits (68), Expect = 0.32
 Identities = 15/48 (31%), Positives = 25/48 (52%), Gaps = 1/48 (2%)

Query: 185 WDHVAMEAEELGFRAGDVIEVLDTLDRDWWW-GTRGEASGWFPSAFVR 231
           +D+ A+  +EL  R G++I  +  L+ + W  G      G FP  FV+
Sbjct: 6   YDYDAVHEDELTIRVGEIIRNVKKLEEEGWLEGELNGRRGMFPDNFVK 53


>gnl|CDD|212858 cd11925, SH3_SH3RF3_3, Third 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 third SH3 domain,
           located in the middle, 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 = 57

 Score = 30.4 bits (68), Expect = 0.32
 Identities = 15/50 (30%), Positives = 26/50 (52%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
           A++ +   + +EL  R G++  V++     W+ GT  R   SG FP  +V
Sbjct: 5   ALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSLRTGVSGVFPGNYV 54


>gnl|CDD|212793 cd11859, SH3_ZO, Src homology 3 domain of the Tight junction
           proteins, Zonula occludens (ZO) proteins.  ZO proteins
           are scaffolding proteins that associate with each other
           and with other proteins of the tight junction, zonula
           adherens, and gap junctions. They play roles in
           regulating cytoskeletal dynamics at these cell
           junctions. They are considered 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. Vertebrates contain three ZO proteins (ZO-1,
           ZO-2, and ZO-3) with redundant and non-redundant roles.
           They contain three PDZ domains, followed by SH3 and GuK
           domains; in addition, ZO-1 and ZO-2 contains a
           proline-rich (PR) actin binding domain at the C-terminus
           while ZO-3 contains this PR domain between the second
           and third PDZ domains. The C-terminal regions of the
           three ZO proteins are unique. The SH3 domain of ZO-1 has
           been shown to bind ZONAB, ZAK, afadin, and Galpha12. 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 = 30.3 bits (69), Expect = 0.33
 Identities = 10/24 (41%), Positives = 14/24 (58%)

Query: 186 DHVAMEAEELGFRAGDVIEVLDTL 209
           D+      EL F+ G+V  V+DTL
Sbjct: 7   DYEKPAKGELSFKKGEVFHVVDTL 30


>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 = 30.1 bits (68), Expect = 0.36
 Identities = 11/35 (31%), Positives = 19/35 (54%), Gaps = 4/35 (11%)

Query: 197 FRAGDVIEVLDTLDRDWW----WGTRGEASGWFPS 227
           F+ GD+++++   D +WW     G   E +G  PS
Sbjct: 25  FKTGDILQIISKDDHNWWQARKPGASKEPAGLIPS 59


>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 = 30.2 bits (68), Expect = 0.38
 Identities = 15/39 (38%), Positives = 25/39 (64%), Gaps = 2/39 (5%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLD--TLDRDWWW 215
           +LA A++D+ A  ++EL FR GD++ VL+      + WW
Sbjct: 1   LLARALYDNKADCSDELAFRRGDILTVLEQNVPGSEGWW 39


>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 = 30.0 bits (68), Expect = 0.38
 Identities = 11/27 (40%), Positives = 14/27 (51%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVL 206
              A  D   +E  EL FR GD IE++
Sbjct: 1   SCTAKMDFEGVEPGELSFRQGDSIEII 27


>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 = 29.8 bits (67), Expect = 0.38
 Identities = 15/54 (27%), Positives = 26/54 (48%), Gaps = 5/54 (9%)

Query: 180 LAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWG---TRGEASGWFPSAFV 230
           L  A++ +      +LGF  G+ + +L+    +WW     T G+  G+ P  FV
Sbjct: 1   LVVALYSYEPSHDGDLGFEKGEKLRILEQ-SGEWWKAQSLTTGQ-EGFIPFNFV 52


>gnl|CDD|212726 cd11792, SH3_Fut8, Src homology 3 domain of
           Alpha1,6-fucosyltransferase (Fut8).  Fut8 catalyzes the
           alpha1,6-linkage of a fucose residue from a donor
           substrate to N-linked oligosaccharides on glycoproteins
           in a process called core fucosylation, which is crucial
           for growth factor receptor-mediated biological
           functions. Fut8-deficient mice show severe growth
           retardation, early death, and a pulmonary emphysema-like
           phenotype. Fut8 is also implicated to play roles in
           aging and cancer metastasis. It contains an N-terminal
           coiled-coil domain, a catalytic domain, and a C-terminal
           SH3 domain. The SH3 domain of Fut8 is located in the
           lumen and its role in glycosyl transfer is unclear. 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 = 29.9 bits (68), Expect = 0.41
 Identities = 8/24 (33%), Positives = 13/24 (54%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEV 205
            A++ H     +E+  R GD+I V
Sbjct: 3   VAIYPHKPRNHDEIELRVGDIIGV 26


>gnl|CDD|212949 cd12016, SH3_Tks_2, Second 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 second 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 = 54

 Score = 29.7 bits (67), Expect = 0.48
 Identities = 15/46 (32%), Positives = 26/46 (56%), Gaps = 2/46 (4%)

Query: 187 HVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS-GWFPSAFVR 231
           + A   +E+GF  G V+EV+   + D WW  R +   GW P+ +++
Sbjct: 9   YKAENEDEIGFETGVVVEVIQK-NLDGWWKIRYQGKEGWAPATYLK 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 = 29.9 bits (67), Expect = 0.50
 Identities = 17/54 (31%), Positives = 29/54 (53%), Gaps = 2/54 (3%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS--GWFPSAFV 230
           V   A++D+   E +EL F+AGD +  L+  D   W   R ++   G +P+ +V
Sbjct: 1   VRVRALYDYDGQEQDELSFKAGDELTKLEDEDEQGWCKGRLDSGQVGLYPANYV 54


>gnl|CDD|212714 cd11780, SH3_Sorbs_3, Third (or C-terminal) 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 third 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 = 55

 Score = 29.6 bits (67), Expect = 0.52
 Identities = 16/50 (32%), Positives = 26/50 (52%), Gaps = 2/50 (4%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
           A++ +     +EL  R GD++ V++  D  W+ GT  R    G FP  +V
Sbjct: 4   ALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSERTGLFGTFPGNYV 53


>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 = 29.4 bits (66), Expect = 0.62
 Identities = 14/51 (27%), Positives = 22/51 (43%), Gaps = 2/51 (3%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDR--DWWWGTRGEASGWFPSAFV 230
           + +WD      +EL F+ GD+I +L        WW G      G  P  ++
Sbjct: 3   QGLWDCFGDNPDELSFQRGDLIYILSKEYNMYGWWVGELNGIVGIVPKDYL 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 = 29.6 bits (67), Expect = 0.66
 Identities = 8/20 (40%), Positives = 13/20 (65%)

Query: 195 LGFRAGDVIEVLDTLDRDWW 214
           L F+ GD++ V +  D +WW
Sbjct: 21  LSFKFGDILHVTNASDDEWW 40


>gnl|CDD|237560 PRK13922, PRK13922, rod shape-determining protein MreC;
           Provisional.
          Length = 276

 Score = 32.3 bits (74), Expect = 0.71
 Identities = 21/111 (18%), Positives = 42/111 (37%), Gaps = 24/111 (21%)

Query: 403 GYLLTPVQRICKYPLQLAELLKYTKTDHPDYVKITEALEAMRDVAMLINERKRRMESLEK 462
           G +++PVQR+   P +                 ++   E++  +  L  E +   + L +
Sbjct: 44  GDVVSPVQRVVNAPRE----------------FVSGVFESLASLFDLREENEELKKELLE 87

Query: 463 LAAWQQRVEGWEGE--------DLIETSSQLIHQGEVIRVTSGMWTNTITL 505
           L +  Q +E  E E        +L E+         VI  +   W+  +T+
Sbjct: 88  LESRLQELEQLEAENARLRELLNLKESLDYQFITARVISRSPDPWSQQVTI 138


>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 = 29.4 bits (66), Expect = 0.73
 Identities = 14/39 (35%), Positives = 21/39 (53%), Gaps = 2/39 (5%)

Query: 194 ELGFRAGDVIEVLDTLDRDWWWGT--RGEASGWFPSAFV 230
           EL  + GD++ V    +  W+ GT  R   +G FP +FV
Sbjct: 15  ELELKEGDIVFVHKKREDGWFKGTLQRTGKTGLFPGSFV 53


>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 = 29.2 bits (66), Expect = 0.74
 Identities = 10/24 (41%), Positives = 15/24 (62%), Gaps = 2/24 (8%)

Query: 193 EELGFRAGDVIEVLD--TLDRDWW 214
           EEL F  G+ +E+++    D DWW
Sbjct: 14  EELSFEKGERLEIIEKPEDDPDWW 37


>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 = 29.2 bits (65), Expect = 0.82
 Identities = 16/54 (29%), Positives = 28/54 (51%), Gaps = 2/54 (3%)

Query: 179 VLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS--GWFPSAFV 230
           V   A++D+   EA+EL F+AG+ +  +   D   W   R  +   G +P+ +V
Sbjct: 2   VRVRALYDYTGQEADELSFKAGEELLKIGEEDEQGWCKGRLLSGRIGLYPANYV 55


>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 = 28.9 bits (65), Expect = 1.0
 Identities = 14/53 (26%), Positives = 22/53 (41%), Gaps = 4/53 (7%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDR----DWWWGTRGEASGWFPSAFVR 231
           A++   A    EL    G V+ VL+  D     +WW        G+ PS ++ 
Sbjct: 4   ALYTFEARSPGELSVTEGQVVTVLEKHDLKGNPEWWLVEDRGKQGYVPSNYLA 56


>gnl|CDD|235533 PRK05617, PRK05617, 3-hydroxyisobutyryl-CoA hydrolase; Provisional.
          Length = 342

 Score = 31.7 bits (73), Expect = 1.2
 Identities = 22/71 (30%), Positives = 32/71 (45%), Gaps = 14/71 (19%)

Query: 238 DTVEDCLAALASGGS-------KTLRRRTSISL-LSNDQVR---SRVVRELINTERDFVK 286
           DTVED +AAL + G         TLR R+  SL ++ +Q+R      + E +  E     
Sbjct: 239 DTVEDIIAALEADGGEFAAKTADTLRSRSPTSLKVTLEQLRRARGLTLEECLRRELRLAL 298

Query: 287 VL---HDVSEG 294
            +    D  EG
Sbjct: 299 AMLRSPDFVEG 309


>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 = 28.7 bits (64), Expect = 1.2
 Identities = 12/38 (31%), Positives = 19/38 (50%), Gaps = 4/38 (10%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTR----GEASGWFPSA 228
           L FR GD+++++D  D  WW   +       +G  PS 
Sbjct: 23  LPFRKGDILQIVDQNDSLWWQARKLSDLAACAGLIPSN 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 = 28.5 bits (63), Expect = 1.4
 Identities = 20/63 (31%), Positives = 35/63 (55%), Gaps = 6/63 (9%)

Query: 175 EDFVVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEA--SGWFPSAFVRL 232
           E+ VV+A+  +D+VA + +EL  +  + + +LD  D   WW  R     +G+ PS +V  
Sbjct: 1   EEVVVVAK--FDYVAQQDQELDIKKNERLWLLD--DSKSWWRVRNAMNKTGFVPSNYVER 56

Query: 233 RVS 235
           + S
Sbjct: 57  KNS 59


>gnl|CDD|212953 cd12020, SH3_Tks5_5, Fifth (C-terminal) 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 fifth (C-terminal) 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 = 57

 Score = 28.4 bits (63), Expect = 1.4
 Identities = 14/45 (31%), Positives = 22/45 (48%), Gaps = 6/45 (13%)

Query: 191 EAEELGFRAGDVIEVLDTLDRDWWW-----GTRGEASGWFPSAFV 230
           + E  GF+ G  +EVL+     WW+     G +    GW PS ++
Sbjct: 11  DEETAGFQEGVSMEVLEKNPNGWWYCQILDGVKPF-KGWVPSNYL 54


>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 = 28.4 bits (64), Expect = 1.5
 Identities = 9/34 (26%), Positives = 19/34 (55%), Gaps = 1/34 (2%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVL-DTLDRDWW 214
            A ++      E+L F+ GD++ ++  T D +W+
Sbjct: 5   IAKYNFNGASEEDLPFKKGDILTIVAVTKDPNWY 38


>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 = 28.4 bits (63), Expect = 1.5
 Identities = 14/52 (26%), Positives = 26/52 (50%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVRL 232
           A   +D  A   +EL  + GD++ +   +D++W  G      G FP+ +V +
Sbjct: 3   ARLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRVGIFPANYVEV 54


>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 = 28.5 bits (64), Expect = 1.5
 Identities = 11/27 (40%), Positives = 16/27 (59%), Gaps = 2/27 (7%)

Query: 194 ELG--FRAGDVIEVLDTLDRDWWWGTR 218
           ELG  F+ GD++ V+   D +WW   R
Sbjct: 20  ELGLSFQKGDILHVISQEDPNWWQAYR 46


>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 = 28.1 bits (63), Expect = 1.6
 Identities = 16/54 (29%), Positives = 24/54 (44%), Gaps = 7/54 (12%)

Query: 182 EAVWDHVAMEAEELGFRAGDVIEVLDTLDRD----WWWGT--RGEASGWFPSAF 229
             + D  A   +EL  + GD IE++   D +    W+ G   R   +G FP  F
Sbjct: 3   IVIHDFNARSEDELTLKPGDKIELI-EDDEEFGDGWYLGRNLRTGETGLFPVVF 55


>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 = 28.5 bits (63), Expect = 1.6
 Identities = 11/39 (28%), Positives = 23/39 (58%), Gaps = 3/39 (7%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGT---RGEASGWFPSAFV 230
           L F  G+++++++  D +WW  +    G ++G  PS F+
Sbjct: 23  LKFSKGEILQIVNREDPNWWQASHVKEGGSAGLIPSQFL 61


>gnl|CDD|241482 cd13328, PH1_FDG_family, FYVE, RhoGEF and PH domain
           containing/faciogenital dysplasia family proteins
           pleckstrin homology (PH), N-terminal domain.  In
           general, FGDs have a RhoGEF (DH) domain, followed by an
           N-terminal PH domain, a FYVE domain and a C-terminal PH
           domain. All FGDs are guanine nucleotide exchange factors
           that activates the Rho GTPase Cdc42, an important
           regulator of membrane trafficking. The RhoGEF domain is
           responsible for GEF catalytic activity, while the
           N-terminal PH domain is involved in intracellular
           targeting of the DH domain. Mutations in the FGD1 gene
           are responsible for the X-linked disorder known as
           faciogenital dysplasia (FGDY). PH domains have diverse
           functions, but in general are involved in targeting
           proteins to the appropriate cellular location or in the
           interaction with a binding partner. They share little
           sequence conservation, but all have a common fold, which
           is electrostatically polarized. Less than 10% of PH
           domains bind phosphoinositide phosphates (PIPs) with
           high affinity and specificity. PH domains are
           distinguished from other PIP-binding domains by their
           specific high-affinity binding to PIPs with two vicinal
           phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or
           PtdIns(3,4,5)P3 which results in targeting some PH
           domain proteins to the plasma membrane. A few display
           strong specificity in lipid binding. Any specificity is
           usually determined by loop regions or insertions in the
           N-terminus of the domain, which are not conserved across
           all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinase,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, as well as cytoskeletal associated
           molecules and in lipid associated enzymes.
          Length = 91

 Score = 29.3 bits (66), Expect = 1.6
 Identities = 23/80 (28%), Positives = 32/80 (40%), Gaps = 8/80 (10%)

Query: 505 LFLFDHQLVYCKRDILKRNTHVYKARLNIDTSQIINLPDGKDPHLGVTVRHAIKIHCSDK 564
           LFLF+  L+YC    L+     Y  R  +D    +N+   K       V H   I    K
Sbjct: 20  LFLFNDMLLYC-VPKLRLIGQKYGVRARMDVDG-MNVQVVKGD----EVPHTFYI--EGK 71

Query: 565 DKWLLFCCRSLEDKARWLAA 584
            K L     + E+K  W+ A
Sbjct: 72  QKSLELQASTAEEKDAWIDA 91


>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 = 28.2 bits (63), Expect = 1.7
 Identities = 17/47 (36%), Positives = 21/47 (44%), Gaps = 4/47 (8%)

Query: 187 HVAMEAEELGFRAGDVIEVLDTLDRDWWWGTR---GEASGWFPSAFV 230
           + A E +EL     D+I V       W  G R   GE  GWFP + V
Sbjct: 8   YKAQENDELTLEKADIIMVRQQSSDGWLEGVRLSDGE-RGWFPQSHV 53


>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 = 28.1 bits (62), Expect = 2.2
 Identities = 7/20 (35%), Positives = 13/20 (65%)

Query: 195 LGFRAGDVIEVLDTLDRDWW 214
           L F+ GD+++++   D  WW
Sbjct: 23  LSFKKGDILQIMSQDDATWW 42


>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 = 28.1 bits (63), Expect = 2.2
 Identities = 13/55 (23%), Positives = 27/55 (49%), Gaps = 2/55 (3%)

Query: 178 VVLAEAVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEAS--GWFPSAFV 230
            V  + ++ + A   +EL    G+ +EV++  D D W   R ++   G+ P  ++
Sbjct: 1   PVTCKVLYSYEAQRPDELTITEGEELEVIEDGDGDGWVKARNKSGEVGYVPENYL 55


>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 = 27.7 bits (61), Expect = 2.4
 Identities = 11/49 (22%), Positives = 24/49 (48%)

Query: 183 AVWDHVAMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFVR 231
            ++ + A + +E+    G V+EV+      WW        GW P+++++
Sbjct: 5   VIYPYTARDQDEINLEKGAVVEVIQKNLEGWWKIRYQGKEGWAPASYLK 53


>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 = 28.1 bits (62), Expect = 2.6
 Identities = 10/30 (33%), Positives = 18/30 (60%)

Query: 189 AMEAEELGFRAGDVIEVLDTLDRDWWWGTR 218
            + ++ L FR GD++ V++  D +WW   R
Sbjct: 21  GLPSQGLSFRYGDILHVINASDDEWWQARR 50


>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 = 27.6 bits (61), Expect = 2.6
 Identities = 12/36 (33%), Positives = 20/36 (55%)

Query: 195 LGFRAGDVIEVLDTLDRDWWWGTRGEASGWFPSAFV 230
           L F   D++ V+  +D +W  G  G+  G FP ++V
Sbjct: 20  LPFAKDDILTVIRRVDENWAEGMLGDKIGIFPISYV 55


>gnl|CDD|218422 pfam05088, Bac_GDH, Bacterial NAD-glutamate dehydrogenase.  This
            family consists of several bacterial proteins which are
            closely related to NAD-glutamate dehydrogenase found in
            Streptomyces clavuligerus. Glutamate dehydrogenases
            (GDHs) are a broadly distributed group of enzymes that
            catalyze the reversible oxidative deamination of
            glutamate to ketoglutarate and ammonia.
          Length = 1526

 Score = 30.6 bits (70), Expect = 3.0
 Identities = 19/50 (38%), Positives = 27/50 (54%), Gaps = 5/50 (10%)

Query: 573  RSLEDKARWLAAFQQERALVEQDREDGLEFAPAAKELARMSAARCHSSRP 622
              LE+ AR +   ++E  L   DR   LEF P+ +ELA  +AA    +RP
Sbjct: 1151 ARLEEHARLIDTLEKEGRL---DRA--LEFLPSDEELAERAAAGQGLTRP 1195


>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 = 27.3 bits (61), Expect = 3.2
 Identities = 14/55 (25%), Positives = 27/55 (49%), Gaps = 3/55 (5%)

Query: 181 AEAVWDHVAMEAEELGFRAGDVIEVL-DTLDRDWWWGTRGEAS--GWFPSAFVRL 232
            + ++D  A   +EL  + GDV+ +L D   +DWW          G  P++++ +
Sbjct: 3   GKVLYDFDAQSDDELTVKEGDVVYILDDKKSKDWWMVENVSTGKEGVVPASYIEI 57


>gnl|CDD|217676 pfam03695, UPF0149, Uncharacterized protein family (UPF0149).  The
           protein in this family are about 190 amino acids long.
           The function of these proteins is unknown.
          Length = 158

 Score = 29.2 bits (66), Expect = 3.3
 Identities = 11/38 (28%), Positives = 17/38 (44%)

Query: 582 LAAFQQERALVEQDREDGLEFAPAAKELARMSAARCHS 619
           LAA        ++D E+G E      E  R++A   +S
Sbjct: 115 LAAIADLEDDEDEDDEEGEEALEELPEYLRVAALLLYS 152


>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 = 27.7 bits (61), Expect = 3.7
 Identities = 10/35 (28%), Positives = 20/35 (57%)

Query: 189 AMEAEELGFRAGDVIEVLDTLDRDWWWGTRGEASG 223
            + ++ L F+ GD++ V++  D +WW   +  A G
Sbjct: 18  GLPSQGLNFKFGDILHVVNASDDEWWQARQVTADG 52


>gnl|CDD|137624 PRK09978, PRK09978, DNA-binding transcriptional regulator GadX;
           Provisional.
          Length = 274

 Score = 29.9 bits (67), Expect = 3.7
 Identities = 28/103 (27%), Positives = 41/103 (39%), Gaps = 10/103 (9%)

Query: 321 ILAFQSSFLED------LETKLDWDAPYKSC--IGETFLKHKSGFRMYSEYCNSHPMAIA 372
           I A  S FLED      L   L  +   + C  I        +  R+ SE   S  +   
Sbjct: 118 IFALLSVFLEDEHFIPLLLNVLQPNMRTRVCTVINNNIAHEWTLARIASELLMSPSLLKK 177

Query: 373 TLQELYQHNNYSKFFEACRLMRGLIEIPLDGYLLTPVQRICKY 415
            L+E  +  +YS+    CR+ R L  I + G+ +  V   C Y
Sbjct: 178 KLRE--EETSYSQLLTECRMQRALQLIVIHGFSIKRVAVSCGY 218


>gnl|CDD|130855 TIGR01796, CM_mono_aroH, monofunctional chorismate mutase, gram
           positive type, clade 1.  This model represents a family
           of monofunctional (non-fused) chorismate mutases from
           gram positive bacteria (Firmicutes) and cyanobacteria.
           Trusted members of the family are found in operons with
           other enzymes of the chorismate pathways, both up- and
           downstream of CM (Listeria, Bacillus, Oceanobacillus) or
           are the sole CM in the genome where the other members of
           the chorismate pathways are found elsewhere in the
           genome (Nostoc, Thermosynechococcus) [Amino acid
           biosynthesis, Aromatic amino acid family].
          Length = 117

 Score = 28.2 bits (63), Expect = 6.3
 Identities = 15/52 (28%), Positives = 23/52 (44%)

Query: 272 RVVRELINTERDFVKVLHDVSEGYLAECRRRNDMFSPEQIQTIFGNLEDILA 323
           R VR     ER+  + + +     L E   RN++   + I  IF   ED+ A
Sbjct: 2   RAVRGATTVERNEAEEIGEAVAELLTELMERNELTPEDLISVIFTVTEDLHA 53


>gnl|CDD|241282 cd01251, PH2_ADAP, ArfGAP with dual PH domains Pleckstrin homology
           (PH) domain, repeat 2.  ADAP (also called centaurin
           alpha) is a phophatidlyinositide binding protein
           consisting of an N-terminal ArfGAP domain and two PH
           domains. In response to growth factor activation, PI3K
           phosphorylates phosphatidylinositol 4,5-bisphosphate to
           phosphatidylinositol 3,4,5-trisphosphate. Centaurin
           alpha 1 is recruited to the plasma membrane following
           growth factor stimulation by specific binding of its PH
           domain to phosphatidylinositol 3,4,5-trisphosphate.
           Centaurin alpha 2 is constitutively bound to the plasma
           membrane since it binds phosphatidylinositol
           4,5-bisphosphate and phosphatidylinositol
           3,4,5-trisphosphate with equal affinity. This cd
           contains the second PH domain repeat. PH domains have
           diverse functions, but in general are involved in
           targeting proteins to the appropriate cellular location
           or in the interaction with a binding partner. They share
           little sequence conservation, but all have a common
           fold, which is electrostatically polarized. Less than
           10% of PH domains bind phosphoinositide phosphates
           (PIPs) with high affinity and specificity. PH domains
           are distinguished from other PIP-binding domains by
           their specific high-affinity binding to PIPs with two
           vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2
           or PtdIns(3,4,5)P3 which results in targeting some PH
           domain proteins to the plasma membrane. A few display
           strong specificity in lipid binding. Any specificity is
           usually determined by loop regions or insertions in the
           N-terminus of the domain, which are not conserved across
           all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinase,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, as well as cytoskeletal associated
           molecules and in lipid associated enzymes.
          Length = 105

 Score = 27.6 bits (62), Expect = 6.9
 Identities = 10/47 (21%), Positives = 18/47 (38%), Gaps = 6/47 (12%)

Query: 541 LPDGKDPHLGVTVRHAIKIHCSDKDKWLLFCCRSLEDKARWLAAFQQ 587
           LP G   H G        +   D+    +    + E++  W+ A Q+
Sbjct: 61  LPAGIKGHWG----FGFTLVTPDRTF--VLSAETEEERREWITAIQK 101


>gnl|CDD|218339 pfam04941, LEF-8, Late expression factor 8 (LEF-8).  Late
           expression factor 8 (LEF-8) is one of the primary
           components of RNA polymerase produced by polyhedrosis
           viruses. LEF-8 shows homology to the second largest
           subunit of prokaryotic DNA-directed RNA polymerase.
          Length = 748

 Score = 29.4 bits (66), Expect = 7.2
 Identities = 15/37 (40%), Positives = 21/37 (56%)

Query: 35  DCTIFGPLIWRSSKEHRKGKKASRNQKCNSGDSGIQI 71
           D  + G LI+  SK   K KK   NQ+ NS ++ I+I
Sbjct: 277 DTIVNGKLIYSVSKTFSKQKKNFPNQQDNSSNNNIEI 313


>gnl|CDD|241253 cd01218, PH_Phafin2-like, Phafin2 (also called EAPF, FLJ13187,
           ZFYVE18 or PLEKHF2) Pleckstrin Homology (PH) domain.
           Phafin2 is differentially expressed in the liver cancer
           cell and regulates the structure and function of the
           endosomes through Rab5-dependent processes. Phafin2
           modulates the cell's response to extracellular
           stimulation by modulating the receptor density on the
           cell surface. Phafin2 contains a PH domain and a FYVE
           domain. PH domains have diverse functions, but in
           general are involved in targeting proteins to the
           appropriate cellular location or in the interaction with
           a binding partner. They share little sequence
           conservation, but all have a common fold, which is
           electrostatically polarized. Less than 10% of PH domains
           bind phosphoinositide phosphates (PIPs) with high
           affinity and specificity. PH domains are distinguished
           from other PIP-binding domains by their specific
           high-affinity binding to PIPs with two vicinal phosphate
           groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3
           which results in targeting some PH domain proteins to
           the plasma membrane. A few display strong specificity in
           lipid binding. Any specificity is usually determined by
           loop regions or insertions in the N-terminus of the
           domain, which are not conserved across all PH domains.
           PH domains are found in cellular signaling proteins such
           as serine/threonine kinase, tyrosine kinases, regulators
           of G-proteins, endocytotic GTPases, adaptors, as well as
           cytoskeletal associated molecules and in lipid
           associated enzymes.
          Length = 123

 Score = 27.6 bits (62), Expect = 9.0
 Identities = 19/83 (22%), Positives = 32/83 (38%), Gaps = 15/83 (18%)

Query: 506 FLFDHQLVYCKRDILKRNTHVYKAR-LNIDTSQIINLPDGKDPHLGVTVRHAIKIHCSDK 564
           FLF+  LVY    I K+     K R + ++  +I +L D  +   G  +    K   S  
Sbjct: 50  FLFNDILVYGSIVINKKK--YNKQRIIPLEDVKIEDLEDTGELKNGWQIISPKK---S-- 102

Query: 565 DKWLLF--CCRSLEDKARWLAAF 585
                F     +  +K+ W+   
Sbjct: 103 -----FVVYAATATEKSEWMDHI 120


>gnl|CDD|241394 cd13240, PH1_Kalirin_Trio_like, Triple functional domain pleckstrin
           homology pleckstrin homology (PH) domain, repeat 1.
           RhoGEFs, Kalirin and Trio, the mammalian homologs of
           Drosophila Trio and Caenorhabditis elegans UNC-73
           regulate a novel step in secretory granule maturation.
           Their signaling modulates the extent to which regulated
           cargo enter and remain in the regulated secretory
           pathway. This allows for fine tuning of peptides
           released by a single secretory cell type with impaired
           signaling leading to pathological states. Trio plays an
           essential role in regulating the actin cytoskeleton
           during axonal guidance and branching. Kalirin and Trio
           are encoded by separate genes in mammals and by a single
           one in invertebrates. Kalirin and Trio share the same
           complex multidomain structure and display several splice
           variants. The longest Kalirin and Trio proteins have a
           Sec14 domain, a stretch of spectrin repeats, a
           RhoGEF(DH)/PH cassette (also called GEF1), an SH3
           domain, a second RhoGEF(DH)/PH cassette (also called
           GEF2), a second SH3 domain, Ig/FNIII domains, and a
           kinase domain. The first RhoGEF(DH)/PH cassette
           catalyzes exchange on Rac1 and RhoG while the second
           RhoGEF(DH)/PH cassette is specific for RhoA. Kalirin and
           Trio are closely related to p63RhoGEF and have PH
           domains of similar function. PH domains have diverse
           functions, but in general are involved in targeting
           proteins to the appropriate cellular location or in the
           interaction with a binding partner. They share little
           sequence conservation, but all have a common fold, which
           is electrostatically polarized. Less than 10% of PH
           domains bind phosphoinositide phosphates (PIPs) with
           high affinity and specificity. PH domains are
           distinguished from other PIP-binding domains by their
           specific high-affinity binding to PIPs with two vicinal
           phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or
           PtdIns(3,4,5)P3 which results in targeting some PH
           domain proteins to the plasma membrane. A few display
           strong specificity in lipid binding. Any specificity is
           usually determined by loop regions or insertions in the
           N-terminus of the domain, which are not conserved across
           all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinase,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, as well as cytoskeletal associated
           molecules and in lipid associated enzymes.not conserved
           across all PH domains. PH domains are found in cellular
           signaling proteins such as serine/threonine kinases,
           tyrosine kinases, regulators of G-proteins, endocytotic
           GTPases, adaptors, cytoskeletal associated molecules,
           and in lipid associated enzymes.
          Length = 123

 Score = 27.7 bits (62), Expect = 9.4
 Identities = 10/30 (33%), Positives = 20/30 (66%), Gaps = 2/30 (6%)

Query: 505 LFLFDHQLVYCK--RDILKRNTHVYKARLN 532
           +FLF+  LV+ K  +D   ++ ++YK++L 
Sbjct: 38  VFLFELCLVFSKEVKDSNGKSKYIYKSKLM 67


  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
   0.321    0.135    0.415 

Gapped
Lambda     K      H
   0.267   0.0813    0.140 


Matrix: BLOSUM62
Gap Penalties: Existence: 11, Extension: 1
Number of Sequences: 44354
Number of Hits to DB: 32,680,275
Number of extensions: 3235507
Number of successful extensions: 3341
Number of sequences better than 10.0: 1
Number of HSP's gapped: 3280
Number of HSP's successfully gapped: 268
Length of query: 630
Length of database: 10,937,602
Length adjustment: 103
Effective length of query: 527
Effective length of database: 6,369,140
Effective search space: 3356536780
Effective search space used: 3356536780
Neighboring words threshold: 11
Window for multiple hits: 40
X1: 16 ( 7.4 bits)
X2: 38 (14.6 bits)
X3: 64 (24.7 bits)
S1: 41 (21.9 bits)
S2: 62 (27.5 bits)