RPS-BLAST 2.2.26 [Sep-21-2011]

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

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

Query= psy1682
         (70 letters)



>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 =  103 bits (260), Expect = 9e-32
 Identities = 37/52 (71%), Positives = 47/52 (90%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          I+VALYDY+ARTD+DLSF+KG+ L+IL+D+ GDWWLAR  +T +EGYIPSNY
Sbjct: 1  IYVALYDYEARTDDDLSFKKGDRLQILDDSDGDWWLARHLSTGKEGYIPSNY 52


>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 = 83.6 bits (206), Expect = 1e-23
 Identities = 38/53 (71%), Positives = 46/53 (86%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          FVALYDY++RT+ DLSF+KGE L+I+N+T+GDWWLA S  T Q GYIPSNYVA
Sbjct: 2  FVALYDYESRTETDLSFKKGERLQIVNNTEGDWWLAHSLTTGQTGYIPSNYVA 54


>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 = 83.5 bits (206), Expect = 1e-23
 Identities = 40/54 (74%), Positives = 47/54 (87%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          IFVALYDY+ART EDLSF+KGE  +I+N+T+GDWW ARS AT + GYIPSNYVA
Sbjct: 2  IFVALYDYEARTTEDLSFKKGERFQIINNTEGDWWEARSIATGKNGYIPSNYVA 55


>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 = 80.1 bits (197), Expect = 4e-22
 Identities = 37/54 (68%), Positives = 45/54 (83%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          +FVALYDY+ART++DLSF KGE  +ILN ++GDWW ARS  T + GYIPSNYVA
Sbjct: 2  LFVALYDYEARTEDDLSFHKGEKFQILNSSEGDWWEARSLTTGETGYIPSNYVA 55


>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 = 72.5 bits (178), Expect = 2e-19
 Identities = 27/53 (50%), Positives = 37/53 (69%), Gaps = 1/53 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +A YD+    + DL  +KGE L++L    G+WWLA+S  T +EGYIPSNYVA+
Sbjct: 3  IAQYDFVPSNERDLQLKKGEKLQVLKSD-GEWWLAKSLTTGKEGYIPSNYVAR 54


>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 = 71.4 bits (176), Expect = 8e-19
 Identities = 22/53 (41%), Positives = 31/53 (58%), Gaps = 1/53 (1%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
            ALYDY A+  ++LSF+KG+ + +L  +   WW  R     +EG  PSNYV 
Sbjct: 5  VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRLG-RGKEGLFPSNYVE 56


>gnl|CDD|212944 cd12011, SH3_SLAP2, Src homology 3 domain of Src-Like Adaptor
          Protein 2.  SLAP2 plays a role in c-Cbl-dependent
          regulation of CSF1R, a tyrosine kinase important for
          myeloid cell growth and differentiation. It has been
          shown to interact with CSF1R, c-Cbl, LAT, CD247, and
          Zap70. SLAPs are adaptor proteins with limited
          similarity to Src family tyrosine kinases. They contain
          an N-terminal SH3 domain followed by an SH2 domain, and
          a unique C-terminal sequence. They function in
          regulating the signaling, ubiquitination, and
          trafficking of T-cell receptor (TCR) and B-cell
          receptor (BCR) components. The SH3 domain of SLAP forms
          a complex with v-Abl. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 70.2 bits (172), Expect = 2e-18
 Identities = 27/56 (48%), Positives = 36/56 (64%), Gaps = 1/56 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          + VAL ++ +    +LS R GE L IL++  GDWW   S  T +E YIPSNYVAK+
Sbjct: 1  VAVALCNFPSGGPTELSIRMGEQLTILSE-DGDWWKVSSAVTGRECYIPSNYVAKV 55


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

 Score = 68.1 bits (166), Expect = 2e-17
 Identities = 33/56 (58%), Positives = 44/56 (78%), Gaps = 1/56 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          I VALY YD   ++DLSF+KGE L+++ +  G+WW ARS  TK+EG+IPSNYVAK+
Sbjct: 1  IVVALYPYDGIHEDDLSFKKGEKLKVIEE-HGEWWKARSLTTKKEGFIPSNYVAKV 55


>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 = 67.1 bits (165), Expect = 4e-17
 Identities = 20/52 (38%), Positives = 30/52 (57%), Gaps = 1/52 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
             ALYDY+A+ D++LSF+KG+ + +L      WW        +EG  P+NY
Sbjct: 1  YARALYDYEAQDDDELSFKKGDIITVLEKDDDGWWEGELN-GGREGLFPANY 51


>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 = 66.1 bits (162), Expect = 8e-17
 Identities = 27/55 (49%), Positives = 32/55 (58%), Gaps = 1/55 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          I VALYD+      DL   KGE   +L+D+   WW AR K    EGYIPSNYV +
Sbjct: 1  IVVALYDFQPIEPGDLPLEKGEEYVVLDDSNEHWWRARDKN-GNEGYIPSNYVTE 54


>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 = 66.4 bits (162), Expect = 9e-17
 Identities = 30/53 (56%), Positives = 36/53 (67%), Gaps = 1/53 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          VALY Y+   D DL F KGE L IL +  G+WW A+S  T QEG+IP N+VAK
Sbjct: 3  VALYSYEPSHDGDLGFEKGEKLRIL-EQSGEWWKAQSLTTGQEGFIPFNFVAK 54


>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 = 65.3 bits (160), Expect = 2e-16
 Identities = 23/48 (47%), Positives = 31/48 (64%), Gaps = 1/48 (2%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPS 50
          VALYDY AR  ++LSF+KG+ + +L  +   WW  R K   +EG IPS
Sbjct: 1  VALYDYTAREPDELSFKKGDIIIVLEKSDDGWWKGRLK-GGKEGLIPS 47


>gnl|CDD|212782 cd11848, SH3_SLAP-like, Src homology 3 domain of Src-Like Adaptor
          Proteins.  SLAPs are adaptor proteins with limited
          similarity to Src family tyrosine kinases. They contain
          an N-terminal SH3 domain followed by an SH2 domain, and
          a unique C-terminal sequence. They function in
          regulating the signaling, ubiquitination, and
          trafficking of T-cell receptor (TCR) and B-cell
          receptor (BCR) components. Vertebrates contain two
          SLAPs, named SLAP (or SLA1) and SLAP2 (or SLA2). SLAP
          has been shown to interact with the EphA receptor,
          EpoR, Lck, PDGFR, Syk, CD79a, among others, while SLAP2
          interacts with CSF1R. Both SLAPs interact with c-Cbl,
          LAT, CD247, and Zap70. SLAP modulates TCR surface
          expression levels as well as surface and total BCR
          levels. As an adaptor to c-Cbl, SLAP increases the
          ubiquitination, intracellular retention, and targeted
          degradation of the BCR complex components. SLAP2 plays
          a role in c-Cbl-dependent regulation of CSF1R, a
          tyrosine kinase important for myeloid cell growth and
          differentiation. The SH3 domain of SLAP forms a complex
          with v-Abl. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 55

 Score = 64.5 bits (157), Expect = 4e-16
 Identities = 27/54 (50%), Positives = 36/54 (66%), Gaps = 1/54 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          VAL DY +    +LS R GE L I++D +GDWW   S+ T +E YIPS +VAK+
Sbjct: 3  VALGDYPSGGPAELSLRLGEPLTIVSD-EGDWWKVLSEVTGRESYIPSVHVAKV 55


>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 = 58.5 bits (142), Expect = 1e-13
 Identities = 26/54 (48%), Positives = 31/54 (57%), Gaps = 3/54 (5%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILN--DTQGDWWLARSKATKQEGYIPSNYVA 54
          VALY +    DE+LSF KGE LEI+   +   DWW AR  A    G +P NYV 
Sbjct: 3  VALYPFTGENDEELSFEKGERLEIIEKPEDDPDWWKAR-NALGTTGLVPRNYVE 55


>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 = 56.9 bits (138), Expect = 5e-13
 Identities = 22/54 (40%), Positives = 38/54 (70%), Gaps = 2/54 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQG-DWWLARSKATKQEGYIPSNYVAK 55
          +A Y+++  ++EDL F+KG+ L I+  T+  +W+ A++K   +EG IP+NYV K
Sbjct: 5  IAKYNFNGASEEDLPFKKGDILTIVAVTKDPNWYKAKNK-DGREGMIPANYVQK 57


>gnl|CDD|212784 cd11850, SH3_Abl, Src homology 3 domain of the Protein Tyrosine
          Kinase, Abelson kinase.  Abl (or c-Abl) is a
          ubiquitously-expressed cytoplasmic (or nonreceptor) PTK
          that contains SH3, SH2, and tyr kinase domains in its
          N-terminal region, as well as nuclear localization
          motifs, a putative DNA-binding domain, and F- and
          G-actin binding domains in its C-terminal tail. It also
          contains a short autoinhibitory cap region in its
          N-terminus. Abl function depends on its subcellular
          localization. In the cytoplasm, Abl plays a role in
          cell proliferation and survival. In response to DNA
          damage or oxidative stress, Abl is transported to the
          nucleus where it induces apoptosis. In chronic
          myelogenous leukemia (CML) patients, an aberrant
          translocation results in the replacement of the first
          exon of Abl with the BCR (breakpoint cluster region)
          gene. The resulting BCR-Abl fusion protein is
          constitutively active and associates into tetramers,
          resulting in a hyperactive kinase sending a continuous
          signal. This leads to uncontrolled proliferation,
          morphological transformation and anti-apoptotic
          effects. BCR-Abl is the target of selective inhibitors,
          such as imatinib (Gleevec), used in the treatment of
          CML. Abl2, also known as ARG (Abelson-related gene), is
          thought to play a cooperative role with Abl in the
          proper development of the nervous system. The Tel-ARG
          fusion protein, resulting from reciprocal translocation
          between chromosomes 1 and 12, is associated with acute
          myeloid leukemia (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 = 56

 Score = 56.7 bits (137), Expect = 6e-13
 Identities = 25/55 (45%), Positives = 37/55 (67%), Gaps = 1/55 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQ-GDWWLARSKATKQEGYIPSNYVA 54
          +FVALYD+ A  +  LS +KGE L +L   + G+W  A SK+T  +G++PSNY+ 
Sbjct: 1  LFVALYDFVASGENQLSIKKGEQLRVLGYNKNGEWCEAESKSTGGQGWVPSNYIT 55


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

 Score = 56.0 bits (135), Expect = 1e-12
 Identities = 28/51 (54%), Positives = 32/51 (62%), Gaps = 1/51 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VALYDY     +DL  RKGE   IL ++   WW AR K   +EGYIPSNYV
Sbjct: 4  VALYDYTPMNAQDLQLRKGEEYVILEESNLPWWRARDK-NGREGYIPSNYV 53


>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 = 55.1 bits (133), Expect = 2e-12
 Identities = 19/55 (34%), Positives = 29/55 (52%), Gaps = 2/55 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
           +VA+ D+ A  D  LSF  G+ L +L     DWW A        GYIP++++ +
Sbjct: 1  EYVAIADFVATDDSQLSFESGDKLLVLRKPSVDWWWAEHNGCC--GYIPASHLHQ 53


>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 = 53.8 bits (130), Expect = 6e-12
 Identities = 23/54 (42%), Positives = 34/54 (62%), Gaps = 2/54 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          +F ALYDY+A+  ++LSF +G+ L I + +  +WW A      + G IPSNYV 
Sbjct: 1  VFRALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCG--GKTGLIPSNYVE 52


>gnl|CDD|212818 cd11885, SH3_SH3TC, Src Homology 3 domain of SH3 domain and
          tetratricopeptide repeat-containing (SH3TC) proteins
          and similar domains.  This subfamily is composed of
          vertebrate SH3TC proteins and hypothetical fungal
          proteins containing BAR and SH3 domains. Mammals
          contain two SH3TC proteins, SH3TC1 and SH3TC2. The
          function of SH3TC1 is unknown. SH3TC2 is localized in
          Schwann cells in the peripheral nervous system, where
          it interacts with Rab11 and plays a role in peripheral
          nerve myelination. Mutations in SH3TC2 are associated
          with Charcot-Marie-Tooth disease type 4C, a severe
          hereditary peripheral neuropathy with symptoms that
          include progressive scoliosis, delayed age of walking,
          muscular atrophy, distal weakness, and reduced nerve
          conduction velocity. SH3 domains bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs; they play a role in the
          regulation of enzymes by intramolecular interactions,
          changing the subcellular localization of signal pathway
          components and mediate multiprotein complex assemblies.
          Length = 55

 Score = 53.5 bits (129), Expect = 8e-12
 Identities = 17/54 (31%), Positives = 33/54 (61%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQ--GDWWLARSKATKQEGYIPSNYV 53
            A  D++     +LSFR+G+ +EI+ D      W++ RSK++ + G++P+N+ 
Sbjct: 2  CTAKMDFEGVEPGELSFRQGDSIEIIGDLIPGLQWFVGRSKSSGRVGFVPTNHF 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 = 53.7 bits (129), Expect = 9e-12
 Identities = 23/59 (38%), Positives = 36/59 (61%), Gaps = 5/59 (8%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSK----ATKQEGYIPSNYVAK 55
          I+ AL+D+ AR DE+LSF+ G+   I  +  GDWW A           +G++P+NY+A+
Sbjct: 1  IYKALWDFKARGDEELSFQAGDQFRIA-ERSGDWWTALKLDRAGGVVAQGFVPNNYLAR 58


>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 = 53.0 bits (128), Expect = 1e-11
 Identities = 22/47 (46%), Positives = 31/47 (65%), Gaps = 2/47 (4%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSN 51
          LYD+ AR  ++LS  KGE+LE+L+D+   WW  R+    Q GY+P N
Sbjct: 5  LYDFTARNSKELSVLKGEYLEVLDDS-RQWWKVRNSR-GQVGYVPHN 49


>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 = 53.1 bits (128), Expect = 1e-11
 Identities = 19/52 (36%), Positives = 39/52 (75%), Gaps = 1/52 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQG-DWWLARSKATKQEGYIPSNYV 53
            LYD+DA++D++L+ ++G+ + IL+D +  DWW+  + +T +EG +P++Y+
Sbjct: 4  KVLYDFDAQSDDELTVKEGDVVYILDDKKSKDWWMVENVSTGKEGVVPASYI 55


>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 = 52.7 bits (127), Expect = 2e-11
 Identities = 19/50 (38%), Positives = 29/50 (58%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYD+ +     LSF +GE   +L  +   WWL  +  + + GY+P+NYV
Sbjct: 4  ALYDFKSAEPNTLSFSEGETFLLLERSNAHWWLV-TNHSGETGYVPANYV 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 = 51.1 bits (123), Expect = 7e-11
 Identities = 18/55 (32%), Positives = 35/55 (63%), Gaps = 2/55 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
           +VA+ DY+A+ D+++S ++GE +E+L      WW  R     +EG++P++Y+  
Sbjct: 1  SYVAIADYEAQGDDEISLQEGEVVEVLEKNDSGWWYVR--KGDKEGWVPASYLEP 53


>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 = 51.2 bits (123), Expect = 7e-11
 Identities = 23/52 (44%), Positives = 30/52 (57%), Gaps = 1/52 (1%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          AL+D+    DEDL F+KGE L ++   +  WW AR+   K  G IP  YV K
Sbjct: 5  ALFDFPGNDDEDLPFKKGEILTVIRKPEEQWWNARNSEGK-TGMIPVPYVEK 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 = 50.9 bits (122), Expect = 1e-10
 Identities = 23/50 (46%), Positives = 36/50 (72%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDYD +T+E+LSF +G+ L++ +D+  DW L     T Q G++P+NY+
Sbjct: 4  ALYDYDKQTEEELSFNEGDTLDVYDDSDSDWILVGFNGT-QFGFVPANYI 52


>gnl|CDD|212943 cd12010, SH3_SLAP, Src homology 3 domain of Src-Like Adaptor
          Protein.  SLAP (or SLA1) modulates TCR surface
          expression levels as well as surface and total BCR
          levels. As an adaptor to c-Cbl, SLAP increases the
          ubiquitination, intracellular retention, and targeted
          degradation of the BCR complex components. SLAP has
          been shown to interact with the EphA receptor, EpoR,
          Lck, PDGFR, Syk, CD79a, c-Cbl, LAT, CD247, and Zap70,
          among others. SLAPs are adaptor proteins with limited
          similarity to Src family tyrosine kinases. They contain
          an N-terminal SH3 domain followed by an SH2 domain, and
          a unique C-terminal sequence. The SH3 domain of SLAP
          forms a complex with v-Abl. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 50.6 bits (121), Expect = 2e-10
 Identities = 22/54 (40%), Positives = 29/54 (53%), Gaps = 1/54 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
            L DY +    +  F  GE L +L+D +G WW  RS  T +E YIP   VAK+
Sbjct: 3  AVLADYPSPDISEPIFHMGEKLRVLSD-EGGWWKVRSLQTGRENYIPGKCVAKV 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 = 50.1 bits (120), Expect = 2e-10
 Identities = 24/51 (47%), Positives = 36/51 (70%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA YDY A+ D++LS +K E L +L+D++  WW  ++ +  Q GY+PSNYV
Sbjct: 3  VAKYDYTAQGDQELSIKKNEKLTLLDDSK-HWWKVQNSS-NQTGYVPSNYV 51


>gnl|CDD|212780 cd11846, SH3_Srms, Src homology 3 domain of Srms Protein Tyrosine
          Kinase.  Src-related kinase lacking C-terminal
          regulatory tyrosine and N-terminal myristoylation sites
          (Srms) is a cytoplasmic (or non-receptor) PTK with
          limited homology to Src kinases. Src kinases in general
          contain an N-terminal SH4 domain with a myristoylation
          site, followed by SH3 and SH2 domains, a tyr kinase
          domain, and a regulatory C-terminal region containing a
          conserved tyr; they are activated by
          autophosphorylation at the tyr kinase domain, but are
          negatively regulated by phosphorylation at the
          C-terminal tyr by Csk (C-terminal Src Kinase). However,
          Srms lacks the N-terminal myristoylation sites. Src
          proteins are involved in signaling pathways that
          regulate cytokine and growth factor responses,
          cytoskeleton dynamics, cell proliferation, survival,
          and differentiation. The SH3 domain of Src kinases
          contributes to substrate recruitment by binding adaptor
          proteins/substrates, and regulation of kinase activity
          through an intramolecular interaction. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 55

 Score = 49.8 bits (119), Expect = 3e-10
 Identities = 21/56 (37%), Positives = 36/56 (64%), Gaps = 2/56 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQE-GYIPSNYVAK 55
          +F ALYD+ AR+  +LS  +G+ L ++ + +GD+  AR      E G +P++YVA+
Sbjct: 1  LFTALYDFTARSTHELSVEQGDKLCVIEE-EGDYIFARKLTGNPESGLVPASYVAQ 55


>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 = 49.3 bits (118), Expect = 4e-10
 Identities = 21/52 (40%), Positives = 33/52 (63%), Gaps = 2/52 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          +AL+ Y A+ +++LSF+KG+ + +L+    DWW  R +   Q G  PSNYV 
Sbjct: 3  IALFPYTAQNEDELSFQKGDIINVLSKDDPDWW--RGELNGQTGLFPSNYVE 52


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

 Score = 49.0 bits (117), Expect = 5e-10
 Identities = 23/52 (44%), Positives = 32/52 (61%), Gaps = 2/52 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ALY YDA+  ++LSF +G+ +EIL +    WW  R +   +EG  P NYV K
Sbjct: 4  ALYAYDAQDTDELSFNEGDIIEILKEDPSGWWTGRLRG--KEGLFPGNYVEK 53


>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 = 49.0 bits (117), Expect = 5e-10
 Identities = 28/53 (52%), Positives = 35/53 (66%), Gaps = 4/53 (7%)

Query: 4  ALYDYDARTDE--DLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          ALY YDA  D+  +LSF KGE LE+ +DT G WW AR K+  + G  PSNY+ 
Sbjct: 4  ALYPYDASPDDPNELSFEKGEILEV-SDTSGKWWQAR-KSNGETGICPSNYLQ 54


>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 = 49.1 bits (117), Expect = 6e-10
 Identities = 18/50 (36%), Positives = 32/50 (64%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL+D+D + D +L FR+G+ +E+++++  +WW  +     Q G  P NYV
Sbjct: 4  ALFDFDPQEDGELGFRRGDFIEVMDNSDPNWW--KGACHGQTGMFPRNYV 51


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

 Score = 49.0 bits (117), Expect = 6e-10
 Identities = 25/53 (47%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          I VA+YD+      DL    GE   IL      WW AR K   +EGYIPSNYV
Sbjct: 2  IVVAMYDFQPTEPHDLRLETGEEYVILEKNDVHWWKARDK-YGKEGYIPSNYV 53


>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 = 48.6 bits (116), Expect = 6e-10
 Identities = 17/50 (34%), Positives = 28/50 (56%), Gaps = 2/50 (4%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          VALYD+   T+EDLSF++G+ + +      +W   R +   +EG  P  +
Sbjct: 3  VALYDFTGETEEDLSFQRGDRILVTEHLDAEWS--RGRLNGREGIFPRAF 50


>gnl|CDD|213017 cd12141, SH3_DNMBP_C2, 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. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in 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 = 48.6 bits (116), Expect = 1e-09
 Identities = 23/59 (38%), Positives = 37/59 (62%), Gaps = 6/59 (10%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEIL--NDTQG--DWWLARSKATKQEGYIPSNYVAK 55
          ++ A+Y + AR+  +LS    + + IL  +D  G  +WWLA  +A  Q+GY+PSNY+ K
Sbjct: 1  VYYAVYTFKARSPNELSVSANQRVRILEFSDLTGNKEWWLA--EANGQKGYVPSNYIRK 57


>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 = 48.5 bits (116), Expect = 1e-09
 Identities = 20/55 (36%), Positives = 31/55 (56%), Gaps = 1/55 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ++ AL D+ A  + DLSF+KGE L I++     WWLA + +    G +P  Y+  
Sbjct: 1  LYEALSDFQAEQEGDLSFKKGEVLRIISKRADGWWLAEN-SKGNRGLVPKTYLKV 54


>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 = 47.5 bits (113), Expect = 2e-09
 Identities = 20/53 (37%), Positives = 35/53 (66%), Gaps = 2/53 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          VALYDY  ++  ++S +KG+ L +LN +  DWW  + +   ++G++P+ YV K
Sbjct: 3  VALYDYQEKSPREVSMKKGDILTLLNSSNKDWW--KVEVNDRQGFVPAAYVKK 53


>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 = 47.4 bits (113), Expect = 2e-09
 Identities = 16/52 (30%), Positives = 29/52 (55%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          + ALYD+      +LS +K + + I+      WWLA+     +EG++P+ Y+
Sbjct: 2  YKALYDFAGSVANELSLKKDDIVYIVQKEDNGWWLAKKLDESKEGWVPAAYL 53


>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 = 47.4 bits (113), Expect = 2e-09
 Identities = 22/54 (40%), Positives = 35/54 (64%), Gaps = 5/54 (9%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL---NDTQGDWWLARSKATKQEGYIPSNYVA 54
          AL+DY+A   ++LSFR+G+ L +L   +D + +WW AR     +EGY+P N + 
Sbjct: 5  ALFDYEAENGDELSFREGDELTVLRKGDDDETEWWWARLND--KEGYVPRNLLG 56


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

 Score = 47.0 bits (112), Expect = 3e-09
 Identities = 20/52 (38%), Positives = 33/52 (63%), Gaps = 3/52 (5%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILN-DTQGDWWLARSKATKQEGYIPSNYV 53
          VA +D+ A  +++LSF+KG  L++LN +   +W+ A      +EG IP NY+
Sbjct: 3  VAKHDFKATAEDELSFKKGSILKVLNMEDDPNWYKAELDG--KEGLIPKNYI 52


>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 = 46.9 bits (111), Expect = 3e-09
 Identities = 23/51 (45%), Positives = 32/51 (62%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA+ DY       L F KG+HL +L+ + G+WW A +  T + GYIPS+YV
Sbjct: 3  VAIKDYCPTNFTTLKFSKGDHLYVLDTSGGEWWYAHN--TTEMGYIPSSYV 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 = 47.1 bits (112), Expect = 3e-09
 Identities = 18/50 (36%), Positives = 29/50 (58%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A+Y +   T+ DL F +G+ +E+L+   G WW  + +    EG  PSN+V
Sbjct: 4  AVYSWAGETEGDLGFLEGDLIEVLSIGDGSWWSGKLRRNGAEGIFPSNFV 53


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

 Score = 47.0 bits (112), Expect = 4e-09
 Identities = 24/53 (45%), Positives = 32/53 (60%), Gaps = 4/53 (7%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILN--DTQGDWWLARSKATKQEGYIPSNYV 53
          VALYD+      DL+F+KG+ + IL   D+Q DWW  R     +EG  P+NYV
Sbjct: 3  VALYDFAGEQPGDLAFQKGDIITILKKSDSQNDWWTGR--IGGREGIFPANYV 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 = 46.9 bits (111), Expect = 4e-09
 Identities = 21/51 (41%), Positives = 32/51 (62%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          + +YDY A+ D++L+F KG+ + +LN    DWW  + +   Q G  PSNYV
Sbjct: 4  IGMYDYTAQNDDELAFSKGQIINVLNKEDPDWW--KGELNGQVGLFPSNYV 52


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

 Score = 46.5 bits (111), Expect = 5e-09
 Identities = 20/51 (39%), Positives = 30/51 (58%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           ALYD+D  ++  LS  +GE L +L +  GD W    K    EGY+P++Y+
Sbjct: 3  TALYDFDGTSEGTLSMEEGEILLVLEEDGGDGWTRVRKNNGDEGYVPTSYI 53


>gnl|CDD|212811 cd11878, SH3_Bem1p_1, First Src Homology 3 domain of Bud
          emergence protein 1 and similar domains.  Members of
          this subfamily bear similarity to Saccharomyces
          cerevisiae Bem1p, containing two Src Homology 3 (SH3)
          domains at the N-terminus, a central PX domain, and a
          C-terminal PB1 domain. Bem1p is a scaffolding protein
          that is critical for proper Cdc42p activation during
          bud formation in yeast. During budding and mating,
          Bem1p migrates to the plasma membrane where it can
          serve as an adaptor for Cdc42p and some other proteins.
          Bem1p also functions as an effector of the G1 cyclin
          Cln3p and the cyclin-dependent kinase Cdc28p in
          promoting vacuolar fusion. SH3 domains bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs; they play a
          role in the regulation of enzymes by intramolecular
          interactions, changing the subcellular localization of
          signal pathway components and mediate multiprotein
          complex assemblies.
          Length = 54

 Score = 46.1 bits (110), Expect = 7e-09
 Identities = 20/50 (40%), Positives = 32/50 (64%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILND-TQGDWWLARSKATKQEGYIPSNY 52
          ALYDY A+T  +LSF KG+   ++ +  QG+W+ A +  T + G +P +Y
Sbjct: 4  ALYDYRAQTPGELSFSKGDFFHVIGEEDQGEWYEATNPVTGKRGLVPKSY 53


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

 Score = 46.0 bits (109), Expect = 8e-09
 Identities = 20/51 (39%), Positives = 30/51 (58%), Gaps = 1/51 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VALYDY A   ++L+  +G+ + +L     +WW   S    Q+GY P+NYV
Sbjct: 3  VALYDYTANRSDELTIHRGDIIRVLYKDNDNWWFG-SLVNGQQGYFPANYV 52


>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 = 46.0 bits (109), Expect = 8e-09
 Identities = 19/52 (36%), Positives = 30/52 (57%), Gaps = 2/52 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          VA +DY  RT ++LSF++G+ L + +    DWW  R +     G IP  Y++
Sbjct: 5  VACFDYTGRTAQELSFKRGDVLLLHSKASSDWW--RGEHNGMRGLIPHKYIS 54


>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 = 46.2 bits (110), Expect = 8e-09
 Identities = 21/51 (41%), Positives = 29/51 (56%), Gaps = 2/51 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPSNYV 53
          ALYD+D++   +LS R GE L I     GD W   R+ +  + G  PS+YV
Sbjct: 4  ALYDFDSQPSGELSLRAGEVLTITRQDVGDGWLEGRN-SRGEVGLFPSSYV 53


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

 Score = 45.8 bits (109), Expect = 8e-09
 Identities = 20/53 (37%), Positives = 32/53 (60%), Gaps = 4/53 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN--DTQGDWWLARSKATKQEGYIPSNYVA 54
          ALY ++ +   DLSF+ G+ + +L   D+Q DWW  R +   + G  P+NYV+
Sbjct: 4  ALYSFEGQQPCDLSFQAGDRITVLTRTDSQFDWWEGRLRG--RVGIFPANYVS 54


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

 Score = 45.7 bits (108), Expect = 1e-08
 Identities = 21/51 (41%), Positives = 31/51 (60%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +A+YDY A  +++LSF KG+ + +LN    DWW  + +     G  PSNYV
Sbjct: 4  IAMYDYTANNEDELSFSKGQLINVLNKDDPDWW--QGEINGVTGLFPSNYV 52


>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 = 46.0 bits (109), Expect = 1e-08
 Identities = 24/59 (40%), Positives = 37/59 (62%), Gaps = 7/59 (11%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILN---DTQGD--WWLARSKATKQEGYIPSNYVA 54
          ++ AL+DYDAR +++L+ R+G+ +E+L+      GD  WW    K   + G  PSNYVA
Sbjct: 1  LWTALFDYDARGEDELTLRRGQPVEVLSKDAAVSGDEGWWTG--KIGDKVGIFPSNYVA 57


>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 = 45.8 bits (109), Expect = 1e-08
 Identities = 20/51 (39%), Positives = 29/51 (56%), Gaps = 1/51 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           ALYDY A  D ++SF +G+ +  +      WWL  + A  Q+G  P+NYV
Sbjct: 3  KALYDYQAAEDNEISFVEGDIITQIEQIDEGWWLGVN-AKGQKGLFPANYV 52


>gnl|CDD|212718 cd11784, SH3_SH3RF2_3, Third Src Homology 3 domain of SH3 domain
          containing ring finger 2.  SH3RF2 is also called POSHER
          (POSH-eliminating RING protein) or HEPP1 (heart protein
          phosphatase 1-binding protein). It acts as an
          anti-apoptotic regulator of the JNK pathway by binding
          to and promoting the degradation of SH3RF1 (or POSH), a
          scaffold protein that is required for pro-apoptotic JNK
          activation. It may also play a role in cardiac
          functions together with protein phosphatase 1. SH3RF2
          contains an N-terminal RING finger domain and three SH3
          domains. This model represents the third SH3 domain,
          located in the middle, of SH3RF2. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 55

 Score = 45.5 bits (108), Expect = 1e-08
 Identities = 21/54 (38%), Positives = 29/54 (53%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          + VAL+ Y A   E+L  +KGE + +L   Q  W    S  T + G  PSNYV+
Sbjct: 1  MCVALHSYSAHRPEELELQKGEGVRVLGKFQEGWLRGLSLVTGRVGIFPSNYVS 54


>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 = 45.5 bits (109), Expect = 1e-08
 Identities = 15/54 (27%), Positives = 28/54 (51%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
             ++DY A    +LS +KG+ +++L+     WW        + G +PS+YV +
Sbjct: 2  GRVIFDYVATDPNELSLKKGDVVKVLDKDDNGWWEGER--GGRRGLVPSSYVEE 53


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

 Score = 45.7 bits (108), Expect = 1e-08
 Identities = 18/51 (35%), Positives = 30/51 (58%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA Y +    + +LSFRKGEH+ ++     +W+  R   T ++G  P++YV
Sbjct: 4  VAQYTFKGDLEVELSFRKGEHICLIRKVNENWYEGRITGTGRQGIFPASYV 54


>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 = 45.3 bits (108), Expect = 1e-08
 Identities = 19/55 (34%), Positives = 33/55 (60%), Gaps = 2/55 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
            V  ++Y+A+ +++LS RKG+ + +L  +   WW  R +   Q G+ PSNYV +
Sbjct: 1  PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWW--RGECNGQVGWFPSNYVTE 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 = 45.2 bits (107), Expect = 2e-08
 Identities = 19/54 (35%), Positives = 34/54 (62%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +VALY +  + +EDL  R G+ + +L+D+  DWW  + K   + G+ P+N+V +
Sbjct: 2  YVALYKFKPQENEDLEMRPGDKITLLDDSNEDWW--KGKIEDRVGFFPANFVQR 53


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

 Score = 45.0 bits (107), Expect = 2e-08
 Identities = 20/56 (35%), Positives = 32/56 (57%), Gaps = 4/56 (7%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYVAK 55
          + A+YDY A  D+++SF++G+   I+N    D  W     + T Q G +P+NYV  
Sbjct: 2  YRAMYDYAAADDDEVSFQEGDV--IINVEIIDDGWMEGTVQRTGQSGMLPANYVEL 55


>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 = 45.0 bits (107), Expect = 2e-08
 Identities = 18/51 (35%), Positives = 31/51 (60%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
            LY Y+A+  ++L+  +GE LE++ D  GD W+     + + GY+P NY+
Sbjct: 5  KVLYSYEAQRPDELTITEGEELEVIEDGDGDGWVKARNKSGEVGYVPENYL 55


>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 = 44.8 bits (106), Expect = 3e-08
 Identities = 19/52 (36%), Positives = 33/52 (63%), Gaps = 2/52 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ALYD++A  D +L+F+ GE + +L+D+  +WW  +    + EG  P+N+V  
Sbjct: 5  ALYDFEAAEDNELTFKAGEIITVLDDSDPNWW--KGSNHRGEGLFPANFVTA 54


>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 = 44.7 bits (105), Expect = 3e-08
 Identities = 23/55 (41%), Positives = 37/55 (67%), Gaps = 2/55 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          I +A +DY A+ D++L  +K E L +L+D++  WW  R+ A +  GY+PSNYV +
Sbjct: 5  IVIAKWDYTAQQDQELDIKKNERLWLLDDSK-TWWRVRNAANRT-GYVPSNYVER 57


>gnl|CDD|212859 cd11926, SH3_SH3RF1_3, Third Src Homology 3 domain of SH3 domain
          containing ring finger 1, an E3 ubiquitin-protein
          ligase.  SH3RF1 is also called POSH (Plenty of SH3s) or
          SH3MD2 (SH3 multiple domains protein 2). It is a
          scaffold protein that acts as an E3 ubiquitin-protein
          ligase. It plays a role in calcium homeostasis through
          the control of the ubiquitin domain protein Herp. It
          may also have a role in regulating death receptor
          mediated and JNK mediated apoptosis. SH3RF1 also
          enhances the ubiquitination of ROMK1 potassium channel
          resulting in its increased endocytosis. It contains an
          N-terminal RING finger domain and four SH3 domains.
          This model represents the third SH3 domain, located in
          the middle, of SH3RF1. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 44.6 bits (105), Expect = 3e-08
 Identities = 20/54 (37%), Positives = 29/54 (53%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          ++VA+Y Y  R +++L  RKGE   +    Q  W+   S  T + G  P NYVA
Sbjct: 1  VYVAIYPYTPRKEDELELRKGEMFLVFERCQDGWFKGTSMHTSKIGVFPGNYVA 54


>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 = 44.6 bits (106), Expect = 4e-08
 Identities = 18/62 (29%), Positives = 33/62 (53%), Gaps = 9/62 (14%)

Query: 1  IFVALYDYDART--------DEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          +FVAL+DYD  T        +E+L F++G+ +++  D   D +       ++ G +P N 
Sbjct: 1  LFVALFDYDPLTMSPNPDAAEEELPFKEGQLIKVYGDKDADGFYLGEINGRR-GLVPCNM 59

Query: 53 VA 54
          V+
Sbjct: 60 VS 61


>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 = 44.2 bits (105), Expect = 5e-08
 Identities = 17/52 (32%), Positives = 30/52 (57%), Gaps = 2/52 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ALYD++ +   +L FR+G+ + +L+ +  DWW    +   + G  P+NYV  
Sbjct: 4  ALYDFNPQEPGELEFRRGDIITVLDSSDPDWWKGELRG--RVGIFPANYVQP 53


>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 = 43.7 bits (103), Expect = 6e-08
 Identities = 20/54 (37%), Positives = 33/54 (61%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          FVALY + A   +DL F  GE + +++D+  +WW  R K  ++ GY P N++ +
Sbjct: 2  FVALYRFKALEKDDLDFHPGERITVIDDSNEEWW--RGKIGEKTGYFPMNFIIR 53


>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 = 43.6 bits (103), Expect = 7e-08
 Identities = 16/57 (28%), Positives = 33/57 (57%), Gaps = 5/57 (8%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKA-----TKQEGYIPSNY 52
          ++ ALYDY+ +T+++L+ ++ + L +L  +  DWW  + K       +  G +P+ Y
Sbjct: 1  VYKALYDYEPQTEDELTIQEDDILYLLEKSDDDWWKVKLKVNSSDDDEPVGLVPATY 57


>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 = 43.7 bits (104), Expect = 8e-08
 Identities = 22/56 (39%), Positives = 29/56 (51%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDED-------LSFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPS 50
          AL+DYD   D         LSF+KG+ L+I+N    +WW AR       + G IPS
Sbjct: 4  ALFDYDPEEDPLIPCKEAGLSFKKGDILQIVNQDDPNWWQARKVGDPNGRAGLIPS 59


>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 = 43.4 bits (103), Expect = 8e-08
 Identities = 20/56 (35%), Positives = 33/56 (58%), Gaps = 7/56 (12%)

Query: 3  VALYDYDARTDEDLSFRKGEHL-----EILNDTQGDWWLARSKATKQEGYIPSNYV 53
           A YD+ A ++++LSFR G+ L     E+    +G W LA +   ++ G +P+NYV
Sbjct: 3  RAEYDFVAESEDELSFRAGDKLRLAPKELQPRVRG-WLLA-TVDGQKIGLVPANYV 56


>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 = 43.5 bits (102), Expect = 1e-07
 Identities = 19/51 (37%), Positives = 33/51 (64%), Gaps = 2/51 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          ALYD++A  D +L+F+ GE + +L+D+  +WW  + +  +  G  PSN+V 
Sbjct: 6  ALYDFEAVEDNELTFKHGEIIIVLDDSDANWW--KGENHRGVGLFPSNFVT 54


>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 = 42.9 bits (101), Expect = 1e-07
 Identities = 20/51 (39%), Positives = 31/51 (60%), Gaps = 2/51 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          ALYD++A  D++L F  G+ +E+L+ +   WW  R     + G  P+NYVA
Sbjct: 4  ALYDFEALEDDELGFNSGDVIEVLDSSNPSWWKGRLHG--KLGLFPANYVA 52


>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 = 43.2 bits (101), Expect = 1e-07
 Identities = 23/58 (39%), Positives = 38/58 (65%), Gaps = 2/58 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKLKS 58
          + VA +DY A+ D++L  +K E L +L+D++  WW  R+ A  + G++PSNYV +  S
Sbjct: 4  VVVAKFDYVAQQDQELDIKKNERLWLLDDSK-SWWRVRN-AMNKTGFVPSNYVERKNS 59


>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 = 42.7 bits (101), Expect = 2e-07
 Identities = 22/58 (37%), Positives = 38/58 (65%), Gaps = 6/58 (10%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILN--DTQG--DWWLARSKATKQEGYIPSNYVAK 55
          + ALY ++AR+  +LS  +G+ + +L   D +G  +WWL   +   ++GY+PSNY+AK
Sbjct: 2  YYALYTFEARSPGELSVTEGQVVTVLEKHDLKGNPEWWLV--EDRGKQGYVPSNYLAK 57


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

 Score = 42.7 bits (100), Expect = 2e-07
 Identities = 22/52 (42%), Positives = 32/52 (61%), Gaps = 3/52 (5%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYV 53
          ALY + +  DE+L+F KGE ++++   + D  WW  R KA  Q G +P NYV
Sbjct: 5  ALYPFSSSNDEELNFEKGEVMDVIEKPENDPEWWKCR-KANGQVGLVPKNYV 55


>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 = 42.5 bits (100), Expect = 2e-07
 Identities = 13/32 (40%), Positives = 22/32 (68%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDW 34
          VA +DY A+  EDL F +G+ ++IL++   +W
Sbjct: 3  VAQHDYSAQGPEDLEFSQGDTIDILSEVNQEW 34


>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 = 42.4 bits (100), Expect = 2e-07
 Identities = 18/51 (35%), Positives = 29/51 (56%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           A +DY  R++ +LSF+KG+ L +      DWW  R +   Q+G +P  Y+
Sbjct: 3  TAQFDYTGRSERELSFKKGDSLTLYRQVSDDWW--RGQLNGQDGLVPHKYI 51


>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 = 42.7 bits (100), Expect = 2e-07
 Identities = 19/55 (34%), Positives = 33/55 (60%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          F ALY+Y  R +++L  R+G+ ++++      W++  S+ TK  G  P NYV +L
Sbjct: 7  FQALYNYMPRNEDELELREGDVIDVMEKCDDGWFVGTSRRTKFFGTFPGNYVKRL 61


>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 = 42.1 bits (99), Expect = 3e-07
 Identities = 17/51 (33%), Positives = 34/51 (66%), Gaps = 3/51 (5%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
             +D+ A  +++LSF+KG+ L+IL+ +   W+  +++   +EGY+P N+V
Sbjct: 3  RGKFDFTASGEDELSFKKGDVLKILS-SDDIWF--KAELNGEEGYVPKNFV 50


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

 Score = 41.9 bits (98), Expect = 3e-07
 Identities = 18/55 (32%), Positives = 32/55 (58%), Gaps = 1/55 (1%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          + +ALYDY     ++L+ R  E   +L+ ++  WW  + K    EGY+PS+Y+ +
Sbjct: 2  LVIALYDYQTNDPQELALRYNEEYHLLDSSEIHWWRVQDK-NGHEGYVPSSYLVE 55


>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 = 41.8 bits (98), Expect = 3e-07
 Identities = 20/51 (39%), Positives = 31/51 (60%), Gaps = 4/51 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL--NDTQGDWWLARSKATKQEGYIPSNY 52
          AL+DY A   ++LSF++G+ + +L  +    DWW A      +EGY+P NY
Sbjct: 5  ALWDYSAEFPDELSFKEGDMVTVLRKDGEGTDWWWA--SLCGREGYVPRNY 53


>gnl|CDD|212874 cd11941, SH3_ARHGEF37_C2, Second C-terminal Src homology 3 domain
          of Rho guanine nucleotide exchange factor 37.  ARHGEF37
          contains a RhoGEF [or Dbl homology (DH)] domain
          followed by a Bin/Amphiphysin/Rvs (BAR) domain, and two
          C-terminal SH3 domains. Its specific function is
          unknown. Its domain architecture is similar to the
          C-terminal half of DNMBP or Tuba, a cdc42-specific GEF
          that provides a functional link between dynamin, Rho
          GTPase signaling, and actin dynamics, and plays an
          important role in regulating cell junction
          configuration. GEFs activate small GTPases by
          exchanging bound GDP for free GTP. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in 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 = 41.8 bits (98), Expect = 4e-07
 Identities = 19/57 (33%), Positives = 35/57 (61%), Gaps = 6/57 (10%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEIL--NDTQG--DWWLARSKATKQEGYIPSNYVAK 55
          VA Y + AR+  ++S + G+ + +L  +D +G  +W L   +   Q GY+PS+Y+A+
Sbjct: 3  VAAYPFTARSKHEVSLQAGQPVTVLEPHDKKGSPEWSLV--EVNGQRGYVPSSYLAR 57


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

 Score = 41.9 bits (98), Expect = 4e-07
 Identities = 18/50 (36%), Positives = 31/50 (62%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY +D   +  L+ ++GE L I+ + +GD W    K   +EGY+P++Y+
Sbjct: 5  ALYPFDGSNEGTLAMKEGEVLYIIEEDKGDGWTRARKQNGEEGYVPTSYI 54


>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 = 41.9 bits (99), Expect = 4e-07
 Identities = 19/55 (34%), Positives = 30/55 (54%), Gaps = 3/55 (5%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWW---LARSKATKQEGYIPSNY 52
          + VALYD+  ++   LSF+ G+ + +LN     WW   +  S    + G+ PSNY
Sbjct: 1  VVVALYDFTPKSKNQLSFKAGDIIYVLNKDPSGWWDGVIISSSGKVKRGWFPSNY 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 = 41.6 bits (98), Expect = 4e-07
 Identities = 17/50 (34%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDY+ +  ++LSF+ G+ L  L +     W  + +   + G  P+NYV
Sbjct: 4  ALYDYEGQESDELSFKAGDILTKLEEEDEQGW-CKGRLDGRVGLYPANYV 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 = 41.9 bits (98), Expect = 4e-07
 Identities = 21/51 (41%), Positives = 36/51 (70%), Gaps = 5/51 (9%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL---NDTQGDWWLARSKATKQEGYIPSN 51
          AL+DY+A+  ++LSF++G+ + IL   +D++ +WW AR     +EGY+P N
Sbjct: 5  ALWDYEAQNADELSFQEGDAITILRRKDDSETEWWWAR--LNDKEGYVPKN 53


>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 = 41.5 bits (97), Expect = 5e-07
 Identities = 21/54 (38%), Positives = 33/54 (61%), Gaps = 5/54 (9%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGD---WWLARSKATKQEGYIPSN 51
          +  AL+DY+  +D++LSF++G+ + IL     D   WW AR     +EGY+P N
Sbjct: 2  VVYALWDYEGESDDELSFKEGDCMTILRREDEDETEWWWAR--LNDKEGYVPRN 53


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

 Score = 41.5 bits (97), Expect = 5e-07
 Identities = 21/53 (39%), Positives = 28/53 (52%), Gaps = 1/53 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
           ALYD+  R   +L+ ++ E   IL      WW AR +    EG IPSNYV +
Sbjct: 4  KALYDFLPREPSNLALKRAEEYLILEQYDPHWWKARDR-YGNEGLIPSNYVTE 55


>gnl|CDD|212821 cd11888, SH3_ARHGAP9_like, Src Homology 3 domain of Rho
          GTPase-activating protein 9 and similar proteins.  This
          subfamily is composed of Rho GTPase-activating proteins
          including mammalian ARHGAP9, and vertebrate ARHGAPs 12
          and 27. RhoGAPs (or ARHGAPs) bind to Rho proteins and
          enhance the hydrolysis rates of bound GTP. ARHGAP9
          functions as a GAP for Rac and Cdc42, but not for RhoA.
          It negatively regulates cell migration and adhesion. It
          also acts as a docking protein for the MAP kinases Erk2
          and p38alpha, and may facilitate cross-talk between the
          Rho GTPase and MAPK pathways to control actin
          remodeling. ARHGAP27, also called CAMGAP1, shows GAP
          activity towards Rac1 and Cdc42. It binds the adaptor
          protein CIN85 and may play a role in clathrin-mediated
          endocytosis. ARHGAP12 has been shown to display GAP
          activity towards Rac1. It plays a role in regulating
          HFG-driven cell growth and invasiveness. ARHGAPs in
          this subfamily contain SH3, WW, Pleckstin homology
          (PH), and RhoGAP domains. SH3 domains bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs; they play a
          role in the regulation of enzymes by intramolecular
          interactions, changing the subcellular localization of
          signal pathway components and mediate multiprotein
          complex assemblies.
          Length = 54

 Score = 41.2 bits (97), Expect = 5e-07
 Identities = 15/52 (28%), Positives = 24/52 (46%), Gaps = 2/52 (3%)

Query: 3  VALYD--YDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          V LY   Y  +    +S ++GE   +L  +  DWW  R     +  Y+P+ Y
Sbjct: 3  VVLYPFEYTGKDGRKVSIKEGERFLLLKKSNDDWWQVRRPGDSKPFYVPAQY 54


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

 Score = 41.5 bits (97), Expect = 6e-07
 Identities = 18/50 (36%), Positives = 33/50 (66%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A+YD++A  D +L+F+ G+ + IL+D+  +WW  + +  +  G  PSN+V
Sbjct: 5  AIYDFEAAEDNELTFKAGDIITILDDSDPNWW--KGETPQGTGLFPSNFV 52


>gnl|CDD|212845 cd11912, SH3_Bzz1_1, First Src Homology 3 domain of Bzz1 and
          similar domains.  Bzz1 (or Bzz1p) is a
          WASP/Las17-interacting protein involved in endocytosis
          and trafficking to the vacuole. It physically interacts
          with type I myosins and functions in the early steps of
          endocytosis. Together with other proteins, it induces
          membrane scission in yeast. Bzz1 contains an N-terminal
          F-BAR (FES-CIP4 Homology and Bin/Amphiphysin/Rvs), a
          central coiled-coil, and two C-terminal SH3 domains.
          This model represents the first C-terminal SH3 domain.
          SH3 domains are protein interaction domains that bind
          to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 55

 Score = 41.4 bits (98), Expect = 6e-07
 Identities = 16/50 (32%), Positives = 28/50 (56%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           LYDY A  D+++S  +GE + +L    G  W      + +EG +P++Y+
Sbjct: 4  VLYDYTASGDDEVSISEGEEVTVLEPDDGSGWTKVRNGSGEEGLVPTSYI 53


>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 = 41.2 bits (97), Expect = 6e-07
 Identities = 16/50 (32%), Positives = 31/50 (62%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL+D+     E+L F+ G+ +E+L+ +  DWW    +   +EG+ P+++V
Sbjct: 4  ALWDHVTMDPEELGFKAGDVIEVLDMSDKDWWWGSIR--DEEGWFPASFV 51


>gnl|CDD|212717 cd11783, SH3_SH3RF_3, Third Src Homology 3 domain of SH3 domain
          containing ring finger 1 (SH3RF1), SH3RF3, and similar
          domains.  SH3RF1 (or POSH) and SH3RF3 (or POSH2) are
          scaffold proteins that function as E3 ubiquitin-protein
          ligases. They contain an N-terminal RING finger domain
          and four SH3 domains. This model represents the third
          SH3 domain, located in the middle of SH3RF1 and SH3RF3,
          and similar domains. SH3RF1 plays a role in calcium
          homeostasis through the control of the ubiquitin domain
          protein Herp. It may also have a role in regulating
          death receptor mediated and JNK mediated apoptosis.
          SH3RF3 interacts with p21-activated kinase 2 (PAK2) and
          GTP-loaded Rac1. It may play a role in regulating JNK
          mediated apoptosis in certain conditions. SH3 domains
          are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 55

 Score = 41.2 bits (97), Expect = 6e-07
 Identities = 21/54 (38%), Positives = 27/54 (50%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          I+VALY Y  +  ++L  RKGE   +    Q  W+   S  T Q G  P NYV 
Sbjct: 1  IYVALYPYKPQKPDELELRKGEMYTVTEKCQDGWFKGTSLRTGQSGVFPGNYVQ 54


>gnl|CDD|212836 cd11903, SH3_Nck2_3, Third Src Homology 3 domain of Nck2 adaptor
          protein.  Nck2 (also called Nckbeta or Growth factor
          receptor-bound protein 4, Grb4) plays a crucial role in
          connecting signaling pathways of tyrosine kinase
          receptors and important effectors in actin dynamics and
          cytoskeletal remodeling. It binds neuronal signaling
          proteins such as ephrinB and Disabled-1 (Dab-1)
          exclusively. Nck adaptor proteins regulate actin
          cytoskeleton dynamics by linking proline-rich effector
          molecules to protein tyrosine kinases and
          phosphorylated signaling intermediates. They contain
          three SH3 domains and a C-terminal SH2 domain. They
          function downstream of the PDGFbeta receptor and are
          involved in Rho GTPase signaling and actin dynamics.
          Vertebrates contain two Nck adaptor proteins: Nck1
          (also called Nckalpha) and Nck2, which show partly
          overlapping functions but also bind distinct targets.
          The third SH3 domain of Nck appears to prefer ligands
          with a PxAPxR motif. SH3 domains are protein
          interaction domains that usually bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially a PxxP motif. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 59

 Score = 41.2 bits (96), Expect = 7e-07
 Identities = 20/54 (37%), Positives = 33/54 (61%), Gaps = 3/54 (5%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYVAKL 56
          LY + + T+E+L+F KGE +E++   + D  WW  ++ +  Q G +P NYV  L
Sbjct: 6  LYPFSSVTEEELNFEKGETMEVIEKPENDPEWWKCKN-SRGQVGLVPKNYVVVL 58


>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 = 41.1 bits (97), Expect = 7e-07
 Identities = 15/50 (30%), Positives = 28/50 (56%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A ++++   +++LSF KG+ + +    +G WW        + G+ PSNYV
Sbjct: 4  AKFNFEGTNEDELSFDKGDIITVTQVVEGGWW--EGTLNGKTGWFPSNYV 51


>gnl|CDD|212786 cd11852, SH3_Kalirin_1, First Src homology 3 domain of the RhoGEF
          kinase, Kalirin.  Kalirin, also called Duo, Duet, or
          TRAD, is a large neuronal dual Rho guanine nucleotide
          exchange factor (RhoGEF) that activates Rac1, RhoA, and
          RhoG using two RhoGEF domains. Kalirin exists in many
          isoforms generated by alternative splicing and the use
          of multiple promoters; the major isoforms are
          kalirin-7, -9, and -12, which differ at their
          C-terminal ends. Kalirin-12, the longest isoform,
          contains an N-terminal Sec14p domain, spectrin-like
          repeats, two RhoGEF domains, two SH3 domains, as well
          as Ig, FNIII, and kinase domains at the C-terminal end.
          Kalirin-7 contains only a single RhoGEF domain and does
          not contain an SH3 domain. Kalirin, through its many
          isoforms, interacts with many different proteins and is
          able to localize to different locations within the
          cell. It influences neurite initiation, axon growth,
          dendritic morphogenesis, vesicle trafficking, neuronal
          maintenance, and neurodegeneration. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in 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 = 41.2 bits (97), Expect = 9e-07
 Identities = 17/55 (30%), Positives = 33/55 (60%), Gaps = 6/55 (10%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEIL--NDTQGDWWLARS----KATKQEGYIPSN 51
          V + D++A + ++L+  KG+ +E+L    ++ DW L R+     +  QEG +PS+
Sbjct: 4  VVIEDFEATSSQELTVSKGQTVEVLERPSSRPDWCLVRTLEQDNSPPQEGLVPSS 58


>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 = 41.1 bits (96), Expect = 9e-07
 Identities = 22/60 (36%), Positives = 36/60 (60%), Gaps = 7/60 (11%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILND---TQGD--WWLARSKATKQEGYIPSNYVAK 55
          ++ ALYDY+A  +++LS R+G+ +E+L+      GD  WW    K   + G  P+NYV +
Sbjct: 1  LWTALYDYEASGEDELSLRRGDVVEVLSQDAAVSGDDGWWAG--KIRHRLGIFPANYVTR 58


>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 = 40.7 bits (95), Expect = 1e-06
 Identities = 17/51 (33%), Positives = 27/51 (52%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +A +DY  R+  +LSF+KG  L + +    DWW  R      +G +P  Y+
Sbjct: 3  IAKFDYVGRSARELSFKKGASLLLYHRASDDWWEGRHNGI--DGLVPHQYI 51


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

 Score = 40.5 bits (95), Expect = 1e-06
 Identities = 21/59 (35%), Positives = 37/59 (62%), Gaps = 7/59 (11%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILN-DTQ--GD--WWLARSKATKQEGYIPSNYVA 54
          ++ A++DY+A  +++L+ R+G+ +E+L+ D+   GD  WW    K   + G  PSNYV 
Sbjct: 1  VWTAVFDYEASAEDELTLRRGDRVEVLSKDSAVSGDEGWWTG--KINDRVGIFPSNYVT 57


>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 = 40.6 bits (95), Expect = 1e-06
 Identities = 22/63 (34%), Positives = 34/63 (53%), Gaps = 8/63 (12%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL---NDTQGDWWLARSKATKQEGYIPSNYVAKLKSIE 60
          ALYD  A + E+LSFR+G+ L +L   + +   WWL       Q+G  P+N   +L+ + 
Sbjct: 5  ALYDNAAESPEELSFRRGDVLMVLKREHGSLPGWWLCSLHG--QQGIAPAN---RLRLLP 59

Query: 61 AEP 63
            P
Sbjct: 60 TAP 62


>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 = 40.3 bits (95), Expect = 1e-06
 Identities = 21/56 (37%), Positives = 33/56 (58%), Gaps = 7/56 (12%)

Query: 4  ALYDYDARTDE-DLSFRKGEHLEILN--DTQG---DWWLARSKATKQEGYIPSNYV 53
          ALYD+     E +LS +KG+ + +L+  D  G   +WW  R++  +  G+ PSNYV
Sbjct: 4  ALYDFTPENPEMELSLKKGDIVAVLSKTDPLGRDSEWWKGRTRDGR-IGWFPSNYV 58


>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 = 40.4 bits (94), Expect = 1e-06
 Identities = 19/53 (35%), Positives = 28/53 (52%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          I++ALY Y  + +++L  RKGE   ++   Q  W+   S  T   G  P NYV
Sbjct: 2  IYLALYAYKPQKNDELELRKGEMYRVIEKCQDGWFKGTSLRTGVSGVFPGNYV 54


>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 = 40.0 bits (94), Expect = 2e-06
 Identities = 17/54 (31%), Positives = 30/54 (55%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +  LYDY A+ D++LS  KG+ + ++   +  WW    +   Q+G +P  Y+ K
Sbjct: 2  YSVLYDYTAQEDDELSISKGDVVAVIEKGEDGWWTV--ERNGQKGLVPGTYLEK 53


>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 = 40.4 bits (94), Expect = 2e-06
 Identities = 19/55 (34%), Positives = 31/55 (56%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          + ALY Y  + D++L  R G+ ++++      W++  S+ TKQ G  P NYV  L
Sbjct: 4  YQALYSYAPQNDDELELRDGDIVDVMEKCDDGWFVGTSRRTKQFGTFPGNYVKLL 58


>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 = 40.2 bits (94), Expect = 2e-06
 Identities = 19/50 (38%), Positives = 30/50 (60%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A YD+ A     LSFR+G+ +E+L+    +WW  R + + + G+ P NYV
Sbjct: 4  AQYDFSAEDPSQLSFRRGDIIEVLDCPDPNWW--RGRISGRVGFFPRNYV 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 = 40.0 bits (94), Expect = 2e-06
 Identities = 18/51 (35%), Positives = 29/51 (56%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           ALY + A+ +  LSF KG+ + +L + Q  WW    +   +EG+ P +YV
Sbjct: 3  TALYPWRAKKENHLSFAKGDIITVL-EQQEMWWFGELE-GGEEGWFPKSYV 51


>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 = 39.6 bits (92), Expect = 3e-06
 Identities = 18/51 (35%), Positives = 35/51 (68%), Gaps = 1/51 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +A YD+ A  D++LSF++G+ L++LN+     W  +++   ++G+IP NY+
Sbjct: 4  IAKYDFKATADDELSFKRGDILKVLNEECDQNWY-KAELNGKDGFIPKNYI 53


>gnl|CDD|212951 cd12018, SH3_Tks4_4, Fourth (C-terminal) Src homology 3 domain of
          Tyrosine kinase substrate with four SH3 domains.  Tks4,
          also called SH3 and PX domain-containing protein 2B
          (SH3PXD2B) or HOFI, is a Src substrate and scaffolding
          protein that plays an important role in the formation
          of podosomes and invadopodia, the dynamic actin-rich
          structures that are related to cell migration and
          cancer cell invasion. It is required in the formation
          of functional podosomes, EGF-induced membrane ruffling,
          and lamellipodia generation. It plays an important role
          in cellular attachment and cell spreading. Tks4 is
          essential for the localization of MT1-MMP
          (membrane-type 1 matrix metalloproteinase) to
          invadopodia. It contains an N-terminal Phox homology
          (PX) domain and four SH3 domains. This model
          characterizes the fourth (C-terminal) SH3 domain of
          Tks4. SH3 domains are protein interaction domains that
          bind to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 56

 Score = 39.5 bits (92), Expect = 3e-06
 Identities = 21/58 (36%), Positives = 32/58 (55%), Gaps = 5/58 (8%)

Query: 1  IFVALYDYDARTDEDL-SFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPSNYVAK 55
          ++VA+ D++   DED  SF++G   E+       WW  +  S     EG+IPSNY+ K
Sbjct: 1  LYVAVADFEG--DEDTSSFKEGTVFEVREKNSSGWWFCKVLSGGPVWEGWIPSNYLRK 56


>gnl|CDD|213004 cd12071, SH3_FBP17, Src Homology 3 domain of Formin Binding
          Protein 17.  Formin Binding Protein 17 (FBP17), also
          called FormiN Binding Protein 1 (FNBP1), is involved in
          dynamin-mediated endocytosis. It is recruited to
          clathrin-coated pits late in the endocytosis process
          and may play a role in the invagination and scission
          steps. FBP17 binds in vivo to tankyrase, a protein
          involved in telomere maintenance and mitogen activated
          protein kinase (MAPK) signaling. It contains an
          N-terminal F-BAR (FES-CIP4 Homology and
          Bin/Amphiphysin/Rvs) domain, a Cdc42-binding HR1
          domain, and a C-terminal SH3 domain. The SH3 domain of
          the related protein, CIP4, associates with Gapex-5, a
          Rab31 GEF. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 57

 Score = 39.6 bits (92), Expect = 3e-06
 Identities = 15/50 (30%), Positives = 31/50 (62%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY ++ + +  +S  +GE L ++ + +GD W    +   +EGY+P++Y+
Sbjct: 5  ALYPFEGQNEGTISVAEGEMLYVIEEDKGDGWTRIRRNEDEEGYVPTSYI 54


>gnl|CDD|212855 cd11922, SH3_Sorbs1_2, Second Src Homology 3 domain of Sorbin and
          SH3 domain containing 1 (Sorbs1), also called ponsin.
          Sorbs1 is also called ponsin, SH3P12, or CAP (c-Cbl
          associated protein). It is an adaptor protein
          containing one sorbin homology (SoHo) and three SH3
          domains. It binds Cbl and plays a major role in
          regulating the insulin signaling pathway by enhancing
          insulin-induced phosphorylation of Cbl. Sorbs1, like
          vinexin, localizes at cell-ECM and cell-cell adhesion
          sites where it binds vinculin, paxillin, and afadin. It
          may function in the control of cell motility. Other
          interaction partners of Sorbs1 include c-Abl, Sos,
          flotillin, Grb4, ataxin-7, filamin C, among others. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 58

 Score = 39.6 bits (92), Expect = 4e-06
 Identities = 17/55 (30%), Positives = 31/55 (56%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKLK 57
          +A ++++  T  ++SFRKGE + +L     +W+  R   T ++G  P  YV  +K
Sbjct: 4  IAKFNFNGDTQVEMSFRKGERITLLRQVDENWYEGRIPGTSRQGIFPITYVDVIK 58


>gnl|CDD|212856 cd11923, SH3_Sorbs2_2, Second Src Homology 3 domain of Sorbin and
          SH3 domain containing 2 (Sorbs2), also called
          Arg-binding protein 2 (ArgBP2).  Sorbs2 or ArgBP2 is an
          adaptor protein containing one sorbin homology (SoHo)
          and three SH3 domains. It regulates actin-dependent
          processes including cell adhesion, morphology, and
          migration. It is expressed in many tissues and is
          abundant in the heart. Like vinexin, it is found in
          focal adhesion where it interacts with vinculin and
          afadin. It also localizes in epithelial cell stress
          fibers and in cardiac muscle cell Z-discs. Sorbs2 has
          been implicated to play roles in the signaling of
          c-Arg, Akt, and Pyk2. Other interaction partners of
          Sorbs2 include c-Abl, flotillin, spectrin, dynamin 1/2,
          synaptojanin, PTP-PEST, among others. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 57

 Score = 39.5 bits (92), Expect = 4e-06
 Identities = 17/51 (33%), Positives = 31/51 (60%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA Y+++A T+ +LS RKG+ + +L     +W+  +   T ++G  P +YV
Sbjct: 4  VAKYNFNADTNVELSLRKGDRVVLLKQVDQNWYEGKIPGTNRQGIFPVSYV 54


>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 = 39.6 bits (92), Expect = 4e-06
 Identities = 15/53 (28%), Positives = 32/53 (60%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          + A+Y Y  + +++L  R+G+ ++++      W++  S+ T++ G  P NYVA
Sbjct: 4  YKAVYQYRPQNEDELELREGDRVDVMQQCDDGWFVGVSRRTQKFGTFPGNYVA 56


>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 = 39.2 bits (92), Expect = 4e-06
 Identities = 18/62 (29%), Positives = 31/62 (50%), Gaps = 7/62 (11%)

Query: 1  IFVALYDYDART-------DEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          + VALYDY+  T       +E+LSF  G+ + +      D +        ++G +PSN+V
Sbjct: 1  LMVALYDYNPETMSPNDDPEEELSFHAGDVVRVYGPMDEDGFYYGELEGGRKGLVPSNFV 60

Query: 54 AK 55
           +
Sbjct: 61 QE 62


>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 = 39.2 bits (92), Expect = 4e-06
 Identities = 17/51 (33%), Positives = 25/51 (49%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           ALY Y A  +++LS + G+ +E+       WWL      K  G  P+ YV
Sbjct: 3  KALYSYTANREDELSLQPGDIIEVHEKQDDGWWLGELNGKK--GIFPATYV 51


>gnl|CDD|212711 cd11777, SH3_CIP4_Bzz1_like, Src Homology 3 domain of
          Cdc42-Interacting Protein 4, Bzz1 and similar domains. 
          This subfamily is composed of Cdc42-Interacting Protein
          4 (CIP4) and similar proteins such as Formin Binding
          Protein 17 (FBP17) and FormiN Binding Protein 1-Like
          (FNBP1L), as well as yeast Bzz1 (or Bzz1p). CIP4 and
          FNBP1L are Cdc42 effectors that bind Wiskott-Aldrich
          syndrome protein (WASP) and function in endocytosis.
          CIP4 and FBP17 bind to the Fas ligand and may be
          implicated in the inflammatory response. CIP4 may also
          play a role in phagocytosis. Bzz1 is also a
          WASP/Las17-interacting protein involved in endocytosis
          and trafficking to the vacuole. It physically interacts
          with type I myosins and functions in the early steps of
          endocytosis. Members of this subfamily contain an
          N-terminal F-BAR (FES-CIP4 Homology and
          Bin/Amphiphysin/Rvs) domain as well as at least one
          C-terminal SH3 domain. Bzz1 contains a second SH3
          domain at the C-terminus. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 39.1 bits (91), Expect = 5e-06
 Identities = 16/51 (31%), Positives = 31/51 (60%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           ALY +   ++  +S  +GE L ++ + +GD W    + T +EGY+P++Y+
Sbjct: 3  KALYAFVGSSEGTISMTEGEKLSLVEEDKGDGWTRVRRDTGEEGYVPTSYI 53


>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 = 39.0 bits (91), Expect = 5e-06
 Identities = 19/51 (37%), Positives = 29/51 (56%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VAL+ Y+A   EDL F+KG+ + +L+    DW   + K   + G  PS +V
Sbjct: 3  VALFSYEASQPEDLEFQKGDVILVLSKVNEDWLEGQCKG--KIGIFPSAFV 51


>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 = 38.7 bits (90), Expect = 6e-06
 Identities = 21/50 (42%), Positives = 28/50 (56%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDYDA  D +LSF + + +  +     DWWL     ++  G  PSNYV
Sbjct: 4  ALYDYDAAEDNELSFFENDKIINIEFVDDDWWLGECHGSR--GLFPSNYV 51


>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 = 38.8 bits (90), Expect = 7e-06
 Identities = 16/54 (29%), Positives = 34/54 (62%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +VALY +  + + DL  + G+ + +++D+  DWW  + K+  + G+ P+N+V +
Sbjct: 2  YVALYKFLPQENNDLPLQPGDRVMVVDDSNEDWW--KGKSGDRVGFFPANFVQR 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 = 38.4 bits (89), Expect = 1e-05
 Identities = 20/50 (40%), Positives = 27/50 (54%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDYD +  ++LSF+ G+ L  L D     W      + Q G  P+NYV
Sbjct: 5  ALYDYDGQEQDELSFKAGDELTKLEDEDEQGWCKGRLDSGQVGLYPANYV 54


>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 = 38.5 bits (89), Expect = 1e-05
 Identities = 22/51 (43%), Positives = 31/51 (60%), Gaps = 5/51 (9%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL-NDTQG--DWWLARSKATKQEGYIPSN 51
          ALYD  A + ++LSFRKG+ + +L  DTQG   WWL       ++G +P N
Sbjct: 7  ALYDNVAESPDELSFRKGDIMTVLERDTQGLDGWWLCSLHG--RQGIVPGN 55


>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 = 37.9 bits (88), Expect = 1e-05
 Identities = 24/53 (45%), Positives = 34/53 (64%), Gaps = 5/53 (9%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILN--DTQGDWWLARSKATKQEGYIPSNYV 53
          VALY + A   ++L F+KG+ L+ILN  D Q  W+ A  +   +EGYIP NY+
Sbjct: 3  VALYSFQATESDELPFQKGDILKILNMEDDQN-WYKAELQG--REGYIPKNYI 52


>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 = 37.8 bits (88), Expect = 1e-05
 Identities = 18/56 (32%), Positives = 29/56 (51%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARSKATKQE--GYIPS 50
          A +DYD   D+        ++F+ G+ L+I++    +WW AR     +E  G IPS
Sbjct: 4  AQFDYDPSKDDLIPCQQAGIAFKTGDILQIISKDDHNWWQARKPGASKEPAGLIPS 59


>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 = 38.1 bits (88), Expect = 2e-05
 Identities = 16/50 (32%), Positives = 31/50 (62%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL+D+    D++L F+ G+ +E+++ T  +WW  R      EG+ P+++V
Sbjct: 22 ALWDHVTMDDQELGFKAGDVIEVMDATNKEWWWGR--VLDSEGWFPASFV 69


>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 = 37.7 bits (88), Expect = 2e-05
 Identities = 18/51 (35%), Positives = 26/51 (50%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VALYDY A  D++LSF++G+ + +       W+          G  P NYV
Sbjct: 3  VALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVT--GLFPGNYV 51


>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 = 37.5 bits (87), Expect = 2e-05
 Identities = 17/51 (33%), Positives = 29/51 (56%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VAL+ Y+A+  EDL FR+G+ +++L++    W    S    + G  P  +V
Sbjct: 3  VALHRYEAQGPEDLGFREGDTIDVLSEVNEAWLEGHSDG--RVGIFPKCFV 51


>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 = 37.7 bits (88), Expect = 2e-05
 Identities = 16/56 (28%), Positives = 28/56 (50%), Gaps = 3/56 (5%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLAR---SKATKQEGYIPSNYVAK 55
           ALY Y++  ++DL+F  G+ + +  +   DW+      S    +EG  P N+V  
Sbjct: 5  KALYPYESDHEDDLNFDVGQLITVTEEEDADWYFGEYVDSNGNTKEGIFPKNFVEV 60


>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 = 37.3 bits (87), Expect = 2e-05
 Identities = 15/55 (27%), Positives = 36/55 (65%), Gaps = 3/55 (5%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQ--GD-WWLARSKATKQEGYIPSNY 52
          + + ++D++AR++++L+ + G+ +E++ D +  GD W+L R+  T + G  P  +
Sbjct: 1  LLIVIHDFNARSEDELTLKPGDKIELIEDDEEFGDGWYLGRNLRTGETGLFPVVF 55


>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 = 37.5 bits (87), Expect = 2e-05
 Identities = 21/53 (39%), Positives = 29/53 (54%), Gaps = 1/53 (1%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          ALYDY A+  ++LSF KG  +  ++   G WW       K + Y PSNYV  +
Sbjct: 4  ALYDYRAKRSDELSFCKGALIHNVSKETGGWWKG-DYGGKVQHYFPSNYVEDV 55


>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 = 37.6 bits (87), Expect = 2e-05
 Identities = 17/50 (34%), Positives = 24/50 (48%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A+YDY  +  ++LSF+ GE L  + D     W          G  P+NYV
Sbjct: 6  AVYDYTGQEPDELSFKAGEELLKVEDEDEQGWCKGVTDGGAVGLYPANYV 55


>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 = 37.3 bits (87), Expect = 2e-05
 Identities = 15/51 (29%), Positives = 28/51 (54%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           A Y+++A T  +LSFRKG+ + +      +W+    +   ++G  P +YV
Sbjct: 3  RAKYNFNADTGVELSFRKGDVITLTRRVDENWY--EGRIGGRQGIFPVSYV 51


>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 = 37.3 bits (87), Expect = 2e-05
 Identities = 17/53 (32%), Positives = 25/53 (47%), Gaps = 5/53 (9%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKAT--KQEGYIPSNYV 53
           ALY   A  + +LSF  G+ +  +  +    WL   + T   + G IP NYV
Sbjct: 3  RALYACKAEDESELSFEPGQIITNVQPSDEPGWL---EGTLNGRTGLIPENYV 52


>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 = 37.3 bits (86), Expect = 3e-05
 Identities = 15/53 (28%), Positives = 31/53 (58%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           + A+YDY A+ ++++SFR G+++  +      W     + T + G +P+NY+
Sbjct: 2  TYRAMYDYSAQDEDEVSFRDGDYIVNVQPIDEGWMYGTVQRTGRTGMLPANYI 54


>gnl|CDD|212799 cd11865, SH3_Nbp2-like, Src Homology 3 domain of Saccharomyces
          cerevisiae Nap1-binding protein 2 and similar fungal
          proteins.  This subfamily includes Saccharomyces
          cerevisiae Nbp2 (Nucleosome assembly protein 1
          (Nap1)-binding protein 2), Schizosaccharomyces pombe
          Skb5, and similar proteins. Nbp2 interacts with Nap1,
          which is essential for maintaining proper nucleosome
          structures in transcription and replication. It is also
          the binding partner of the yeast type II protein
          phosphatase Ptc1p and serves as a scaffolding protein
          that brings seven kinases in close contact to Ptc1p.
          Nbp2 plays a role many cell processes including
          organelle inheritance, mating hormone response, cell
          wall stress, mitotic cell growth at elevated
          temperatures, and high osmolarity. Skb5 interacts with
          the p21-activated kinase (PAK) homolog Shk1, which is
          critical for fission yeast cell viability. Skb5
          activates Shk1 and plays a role in regulating cell
          morphology and growth under hypertonic conditions. Nbp2
          and Skb5 contain an SH3 domain. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 37.1 bits (86), Expect = 3e-05
 Identities = 17/51 (33%), Positives = 28/51 (54%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VALYD++   D +L F +G+ L IL      W +A  ++  + G +P  +V
Sbjct: 3  VALYDFEPEHDNELGFAEGQILFILYKHGQGWLIAEDESGGKTGLVPEEFV 53


>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 = 37.1 bits (86), Expect = 3e-05
 Identities = 17/51 (33%), Positives = 27/51 (52%), Gaps = 1/51 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          V LYDY+   D ++   +GE +  +     DWW+  + +  + G  PSNYV
Sbjct: 3  VVLYDYEKDEDNEIELVEGEIVTNIEMVDEDWWMG-TNSKGESGLFPSNYV 52


>gnl|CDD|212829 cd11896, SH3_SNX33, Src Homology 3 domain of Sorting Nexin 33.
          SNX33 interacts with Wiskott-Aldrich syndrome protein
          (WASP) and plays a role in the maintenance of cell
          shape and cell cycle progression. It modulates the
          shedding and endocytosis of cellular prion protein
          (PrP(c)) and amyloid precursor protein (APP). SNXs are
          Phox homology (PX) domain containing proteins that are
          involved in regulating membrane traffic and protein
          sorting in the endosomal system. SNX33 also contains
          BAR and SH3 domains. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 55

 Score = 37.2 bits (86), Expect = 3e-05
 Identities = 14/50 (28%), Positives = 27/50 (54%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY + +   E+++ ++ E L I ++   D WL    +  + G  P++YV
Sbjct: 4  ALYSFQSENKEEINIQENEELVIFSENSLDGWLQGQNSRGETGLFPASYV 53


>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 = 36.9 bits (86), Expect = 3e-05
 Identities = 19/50 (38%), Positives = 26/50 (52%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDY A+  ++LSF K   +  +    G WW       KQ  + P+NYV
Sbjct: 4  ALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGKKQ-KWFPANYV 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 = 36.9 bits (86), Expect = 3e-05
 Identities = 19/51 (37%), Positives = 30/51 (58%), Gaps = 5/51 (9%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN-DTQG--DWWLARSKATKQEGYIPSN 51
          ALYD  A + ++L+FR+G+ L +L  +T G   WWL   +   ++G  P N
Sbjct: 4  ALYDNVAESPDELAFRRGDILTVLEQNTAGLEGWWLCSLRG--RQGIAPGN 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 = 36.7 bits (85), Expect = 3e-05
 Identities = 20/51 (39%), Positives = 29/51 (56%), Gaps = 3/51 (5%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          AL D+ A ++  LSFRKGE L++L     DW   R +   +EG +P  Y +
Sbjct: 4  ALCDH-AGSESQLSFRKGEELQVLGTVDEDW--IRCRRGDREGLVPVGYTS 51


>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 = 36.9 bits (86), Expect = 4e-05
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYD++   + +L F++G+ + + N    +W+        Q G+ P NYV
Sbjct: 5  ALYDFEPENEGELGFKEGDIITLTNQIDENWYEGMVNG--QSGFFPVNYV 52


>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 = 36.2 bits (84), Expect = 5e-05
 Identities = 17/54 (31%), Positives = 28/54 (51%), Gaps = 3/54 (5%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ++ALY Y++    DL+F  G+ + ++    G+WW        + G  PSNYV  
Sbjct: 2  YIALYPYESNEPGDLTFNAGDVI-LVTKKDGEWWTGTIGD--RTGIFPSNYVRP 52


>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 = 36.5 bits (85), Expect = 5e-05
 Identities = 16/55 (29%), Positives = 30/55 (54%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
           + ALY Y  + +++L  R+G+ + ++      W++  S+ T   G  P NYVA+
Sbjct: 1  RYRALYSYTPQNEDELELREGDIVYVMEKCDDGWFVGTSERTGLFGTFPGNYVAR 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 = 36.5 bits (84), Expect = 5e-05
 Identities = 18/52 (34%), Positives = 30/52 (57%), Gaps = 3/52 (5%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +VA+Y Y++    DL+F++G+ + ++    GDWW        + G  PSNYV
Sbjct: 2  YVAMYTYESNEQGDLTFQQGD-VILVTKKDGDWWTG--TVGDKTGVFPSNYV 50


>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 = 36.5 bits (84), Expect = 6e-05
 Identities = 15/52 (28%), Positives = 29/52 (55%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          + A+YDY+A  ++++SF+ G+ +  +      W     + T   G +P+NYV
Sbjct: 5  YRAVYDYNAADEDEVSFQDGDTIVNVQQIDDGWMYGTVERTGDTGMLPANYV 56


>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 = 36.5 bits (84), Expect = 6e-05
 Identities = 18/53 (33%), Positives = 31/53 (58%), Gaps = 1/53 (1%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          AL+DY A+ +++L+F K   ++ +   +G WW       KQ  + PSNYV ++
Sbjct: 8  ALFDYKAQREDELTFTKNAIIQNVEKQEGGWWRGDYGGKKQL-WFPSNYVEEI 59


>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 = 7e-05
 Identities = 16/53 (30%), Positives = 32/53 (60%), Gaps = 4/53 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYVA 54
          AL+ Y+   +++L F++GE + I++   G+  WW  + +   +EG  P N+V+
Sbjct: 6  ALFHYEGTNEDELDFKEGEIILIISKDTGEPGWW--KGELNGKEGVFPDNFVS 56


>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 = 36.1 bits (83), Expect = 7e-05
 Identities = 17/50 (34%), Positives = 26/50 (52%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDY  +  ++LSF+ GE L  + +     W      + + G  P+NYV
Sbjct: 6  ALYDYTGQEADELSFKAGEELLKIGEEDEQGWCKGRLLSGRIGLYPANYV 55


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

 Score = 36.2 bits (84), Expect = 7e-05
 Identities = 16/36 (44%), Positives = 22/36 (61%), Gaps = 4/36 (11%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD----WW 35
          ALYDY+A++DE+LSF +G  + IL          WW
Sbjct: 4  ALYDYEAQSDEELSFPEGAIIRILRKDDNGVDDGWW 39


>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 = 35.8 bits (83), Expect = 8e-05
 Identities = 17/51 (33%), Positives = 27/51 (52%), Gaps = 2/51 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          + A   Y+A+ +++LS   G  +E+L  +   WWL R       GY+PS Y
Sbjct: 2  YYATRAYEAQKEDELSVPAGVVVEVLQKSDNGWWLIRYNGRA--GYVPSMY 50


>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 = 35.9 bits (83), Expect = 8e-05
 Identities = 15/54 (27%), Positives = 31/54 (57%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +  + ++ A   + +SF+KG+ +E+++     WW    K   +EG+ PS+Y+ K
Sbjct: 2  YFTIGEFQATIQDGISFQKGQKVEVIDKNPSGWWYV--KIDGKEGWAPSSYIEK 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 = 35.8 bits (83), Expect = 9e-05
 Identities = 20/56 (35%), Positives = 28/56 (50%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDED-----LSFRKGEHLEILNDTQGDWWLARSKA----TKQEGYIPS 50
          AL+DYD   D       LSF+ G+ L + N +  +WW AR        ++ G IPS
Sbjct: 4  ALFDYDPSRDSGLPSQGLSFKFGDILHVTNASDDEWWQARRVTPNGEEEEVGVIPS 59


>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 = 36.0 bits (83), Expect = 1e-04
 Identities = 18/42 (42%), Positives = 23/42 (54%), Gaps = 2/42 (4%)

Query: 13 DEDLSFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPSNY 52
          D  L FRKG+ L+I++     WW AR  S      G IPSN+
Sbjct: 20 DAGLPFRKGDILQIVDQNDSLWWQARKLSDLAACAGLIPSNH 61


>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 = 35.8 bits (82), Expect = 1e-04
 Identities = 15/50 (30%), Positives = 32/50 (64%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL+D+    D++L+F+ G+ + +L  +  DWW  R++   +E + P+++V
Sbjct: 5  ALWDHVTMDDQELAFKAGDVIRVLEASNKDWWWGRNE--DREAWFPASFV 52


>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 = 35.6 bits (82), Expect = 1e-04
 Identities = 18/54 (33%), Positives = 27/54 (50%), Gaps = 8/54 (14%)

Query: 3  VALYDYDARTDEDLSFRKGE---HLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VALYDY    D+++SF   E    +E++++    WW          G  P+NYV
Sbjct: 4  VALYDYQGEGDDEISFDPQETITDIEMVDE---GWWKGTCHG--HRGLFPANYV 52


>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 = 35.7 bits (82), Expect = 1e-04
 Identities = 19/52 (36%), Positives = 29/52 (55%), Gaps = 3/52 (5%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILND-TQGDWWLARSKATKQEGYIPSNYV 53
           A YD+ AR   +LS ++G+ ++I N   Q  WW  R +   + G+ PS YV
Sbjct: 3  KARYDFCARDMRELSLKEGDVVKIYNKKGQQGWW--RGEINGRIGWFPSTYV 52


>gnl|CDD|212925 cd11992, SH3_Intersectin2_3, Third Src homology 3 domain (or
          SH3C) of Intersectin-2.  Intersectin-2 (ITSN2) is an
          adaptor protein that functions in exo- and endocytosis,
          actin cytoskeletal reorganization, and signal
          transduction. It plays a role in clathrin-coated pit
          (CCP) formation. It binds to many proteins through its
          multidomain structure and facilitate the assembly of
          multimeric complexes. ITSN2 also functions as a
          specific GEF for Cdc42 activation in epithelial
          morphogenesis, and is required in mitotic spindle
          orientation. It exists in alternatively spliced short
          and long isoforms. The short isoform contains two Eps15
          homology domains (EH1 and EH2), a coiled-coil region
          and five SH3 domains (SH3A-E), while the long isoform,
          in addition, contains RhoGEF (also called
          Dbl-homologous or DH), Pleckstrin homology (PH) and C2
          domains. The third SH3 domain (SH3C) of ITSN2 has been
          shown to bind the K15 protein of Kaposi's
          sarcoma-associated herpesvirus. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 52

 Score = 35.4 bits (81), Expect = 1e-04
 Identities = 18/52 (34%), Positives = 28/52 (53%), Gaps = 3/52 (5%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ++ALY Y +    DL+F +GE + ++    G+WW        + G  PSNYV
Sbjct: 2  YIALYPYSSSEPGDLTFNEGEEI-LVTQKDGEWWTGS--IEDRTGIFPSNYV 50


>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 = 35.7 bits (82), Expect = 1e-04
 Identities = 20/56 (35%), Positives = 29/56 (51%), Gaps = 5/56 (8%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEIL-NDTQG--DWWLARSKATKQEGYIPSNYVAKL 56
          ALYD      E+L+FRKG+ L ++  +T G   WWL       ++G  P N +  L
Sbjct: 4  ALYDNVPECAEELAFRKGDILTVIEQNTGGLEGWWLCSLHG--RQGIAPGNRLKLL 57


>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 = 35.4 bits (81), Expect = 1e-04
 Identities = 17/53 (32%), Positives = 29/53 (54%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           F A+YDY A  D+++SF+ G+ +  +      W     + T + G +P+NYV
Sbjct: 3  SFRAMYDYRAADDDEVSFKDGDTIVNVQTIDEGWMYGTVQRTGKTGMLPANYV 55


>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 = 35.0 bits (81), Expect = 2e-04
 Identities = 16/51 (31%), Positives = 26/51 (50%), Gaps = 1/51 (1%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          Y+    TDE LSF+KG+   + N+ +  W    S  T + G +  + V +L
Sbjct: 10 YNKVPDTDE-LSFQKGDIFVVHNELEDGWLWVTSLRTGESGLVFRDLVEEL 59


>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 = 35.3 bits (81), Expect = 2e-04
 Identities = 21/56 (37%), Positives = 30/56 (53%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTD-----EDLSFRKGEHLEILNDTQGDWWLARSKATKQE----GYIPS 50
          AL+DYD   D     + LSFR G+ L +++    +WW AR   +  E    G+IPS
Sbjct: 6  ALFDYDKTKDCGFLSQALSFRFGDVLHVIDAGDEEWWQARRVHSDSETEEIGFIPS 61


>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 = 35.0 bits (80), Expect = 2e-04
 Identities = 16/58 (27%), Positives = 31/58 (53%), Gaps = 2/58 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKLKS 58
          +  A +++    +++LS  KG+ + +    +G WW        + G+ PSNYV ++KS
Sbjct: 3  VVKARFNFKQTNEDELSVCKGDIIYVTRVEEGGWW--EGTLNGKTGWFPSNYVREIKS 58


>gnl|CDD|212791 cd11857, SH3_DBS, Src homology 3 domain of DBL's Big Sister
          (DBS), a guanine nucleotide exchange factor.  DBS, also
          called MCF2L (MCF2-transforming sequence-like protein)
          or OST, is a Rho GTPase guanine nucleotide exchange
          factor (RhoGEF), facilitating the exchange of GDP and
          GTP. It was originally isolated from a cDNA screen for
          sequences that cause malignant growth. It plays roles
          in regulating clathrin-mediated endocytosis and cell
          migration through its activation of Rac1 and Cdc42.
          Depending on cell type, DBS can also activate RhoA and
          RhoG. DBS contains a Sec14-like domain, spectrin-like
          repeats, a RhoGEF [or Dbl homology (DH)] domain, a
          Pleckstrin homology (PH) domain, and an SH3 domain. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 55

 Score = 34.6 bits (80), Expect = 2e-04
 Identities = 11/50 (22%), Positives = 32/50 (64%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSN 51
          +  + DY+    +DL+ + G+ ++++++     WL ++ +T++EG++P+ 
Sbjct: 2  YTVVADYEKGGPDDLTVKSGDLVQLIHEGDEGQWLVKNLSTRKEGWVPAA 51


>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 = 34.6 bits (80), Expect = 2e-04
 Identities = 14/50 (28%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           L+ Y  + +++L  + G+ +E+L + +  WW    K   + G  PSN+V
Sbjct: 4  VLFSYTPQNEDELELKVGDTIEVLGEVEEGWW--EGKLNGKVGVFPSNFV 51


>gnl|CDD|212966 cd12033, SH3_MPP7, Src Homology 3 domain of Membrane Protein,
          Palmitoylated 7 (or MAGUK p55 subfamily member 7).
          MPP7 is a scaffolding protein that binds to DLG1 and
          promotes tight junction formation and epithelial cell
          polarity. Mutations in the MPP7 gene may be associated
          with the pathogenesis of diabetes and extreme bone
          mineral density. It is one of seven vertebrate homologs
          of the Drosophila Stardust protein, which is required
          in establishing cell polarity, and it contains two L27
          domains followed by the core of three domains
          characteristic of MAGUK (membrane-associated guanylate
          kinase) proteins: PDZ, SH3, and guanylate kinase (GuK).
          The GuK domain in MAGUK proteins is enzymatically
          inactive; instead, the domain mediates protein-protein
          interactions and associates intramolecularly with the
          SH3 domain. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 61

 Score = 34.6 bits (79), Expect = 3e-04
 Identities = 20/58 (34%), Positives = 32/58 (55%), Gaps = 9/58 (15%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARSK--ATKQEGYIPSNY 52
          AL+DY+   D+        LSF+KG+ L+I++     WW A+ +  A  + G IPS +
Sbjct: 4  ALFDYNPNEDKAIPCKEAGLSFKKGDILQIMSQDDATWWQAKHEGDANPRAGLIPSKH 61


>gnl|CDD|212827 cd11894, SH3_FCHSD2_2, Second Src Homology 3 domain of FCH and
          double SH3 domains protein 2.  FCHSD2 has a domain
          structure consisting of an N-terminal F-BAR (FES-CIP4
          Homology and Bin/Amphiphysin/Rvs), two SH3, and
          C-terminal proline-rich domains. It has only been
          characterized in silico and its function is unknown.
          SH3 domains are protein interaction domains that bind
          to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 56

 Score = 34.5 bits (79), Expect = 3e-04
 Identities = 16/31 (51%), Positives = 23/31 (74%), Gaps = 1/31 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN-DTQGD 33
          ALYDY+ +TD++LSF +G  + ILN + Q D
Sbjct: 4  ALYDYEGQTDDELSFPEGAIIRILNKENQDD 34


>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 = 34.3 bits (79), Expect = 3e-04
 Identities = 18/50 (36%), Positives = 29/50 (58%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY+Y+ +   DLSF+KG+ + +L     + W       KQ G+ P++YV
Sbjct: 4  ALYNYEGKEPGDLSFKKGD-IILLRKRIDENWYHGECNGKQ-GFFPASYV 51


>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 = 34.5 bits (79), Expect = 3e-04
 Identities = 16/39 (41%), Positives = 23/39 (58%), Gaps = 1/39 (2%)

Query: 16 LSFRKGEHLEILN-DTQGDWWLARSKATKQEGYIPSNYV 53
          L+F+ G+ +E+L  D    WW  R   TK+ GY PS+ V
Sbjct: 20 LTFQTGDVIELLRGDPDSPWWEGRLLQTKKSGYFPSSSV 58


>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 = 34.2 bits (79), Expect = 4e-04
 Identities = 12/32 (37%), Positives = 20/32 (62%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWW 35
          ALYD  A  D++L+F +GE + +  +   +WW
Sbjct: 4  ALYDCQADNDDELTFSEGEIIVVTGEEDDEWW 35


>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 = 34.5 bits (79), Expect = 4e-04
 Identities = 15/39 (38%), Positives = 25/39 (64%), Gaps = 1/39 (2%)

Query: 16 LSFRKGEHLEILN-DTQGDWWLARSKATKQEGYIPSNYV 53
          L+ + G+ +E+L  D +  WW  R+ AT++ GY PS+ V
Sbjct: 22 LTLQTGDVVELLKGDAESPWWEGRNVATREVGYFPSSSV 60


>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 = 34.2 bits (79), Expect = 4e-04
 Identities = 16/52 (30%), Positives = 29/52 (55%), Gaps = 4/52 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYV 53
           L+DY+A  +++L+ R+G+ + IL+    D  WW    +   + G  P N+V
Sbjct: 4  VLFDYEAENEDELTLREGDIVTILSKDCEDKGWWKG--ELNGKRGVFPDNFV 53


>gnl|CDD|212958 cd12025, SH3_Obscurin_like, Src homology 3 domain of Obscurin and
          similar proteins.  Obscurin is a giant muscle protein
          that is concentrated at the peripheries of Z-disks and
          M-lines. It binds small ankyrin I, a component of the
          sarcoplasmic reticulum (SR) membrane. It is associated
          with the contractile apparatus through binding with
          titin and sarcomeric myosin. It plays important roles
          in the organization and assembly of the myofibril and
          the SR. Obscurin has been observed as
          alternatively-spliced isoforms. The major isoform in
          sleletal muscle, approximately 800 kDa in size, is
          composed of many adhesion modules and signaling
          domains. It harbors 49 Ig and 2 FNIII repeats at the
          N-terminues, a complex middle region with additional Ig
          domains, an IQ motif, and a conserved SH3 domain near
          RhoGEF and PH domains, and a non-modular C-terminus
          with phosphorylation motifs. The obscurin gene also
          encodes two kinase domains, which are not part of the
          800 kDa form of the protein, but is part of smaller
          spliced products that present in heart muscle. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in 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 = 34.1 bits (78), Expect = 4e-04
 Identities = 16/61 (26%), Positives = 32/61 (52%), Gaps = 6/61 (9%)

Query: 1  IFVALYDY--DARTDEDLSFRKGEHLEILNDTQGDWWLARSKATK----QEGYIPSNYVA 54
          +++   DY  D    E +   +G+++E+L+      WL R+K TK    ++G++   Y+ 
Sbjct: 3  VYIVTADYTPDGADTEAIPLEEGQYVEVLDSAHPLKWLVRTKPTKSSPPRQGWVSPAYLE 62

Query: 55 K 55
          K
Sbjct: 63 K 63


>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 = 33.8 bits (78), Expect = 4e-04
 Identities = 12/52 (23%), Positives = 24/52 (46%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           +  +DYDA   ++L+ + G+ +  +   +  WW       +  G  P N+V
Sbjct: 2  VIVEFDYDAEEPDELTLKVGDIITNVKKMEEGWWEGTLNGKR--GMFPDNFV 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 = 33.9 bits (78), Expect = 5e-04
 Identities = 12/49 (24%), Positives = 28/49 (57%), Gaps = 2/49 (4%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPS 50
          F+A+  Y  + + ++S  KG+ +++L+  +G +W    +   + G+ PS
Sbjct: 2  FIAVKSYSPQEEGEISLHKGDRVKVLSIGEGGFWEGSVRG--RTGWFPS 48


>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 = 34.1 bits (78), Expect = 5e-04
 Identities = 17/51 (33%), Positives = 26/51 (50%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          V L+D+ A   +DLS   GE + +L     +W+  R K     G  P+N+V
Sbjct: 3  VVLHDFPAEHSDDLSLNSGEIVYLLEKIDTEWY--RGKCKNTTGIFPANHV 51


>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 = 33.9 bits (78), Expect = 5e-04
 Identities = 19/55 (34%), Positives = 31/55 (56%), Gaps = 8/55 (14%)

Query: 3  VALYDYDARTDEDLSFRKGE---HLEILNDTQGDWWLARSKATKQEGYIPSNYVA 54
          VALYDY A  D+++SF   +   ++E++++    WW  R     + G  P+NYV 
Sbjct: 3  VALYDYQAADDDEISFDPDDIITNIEMIDE---GWW--RGVCRGKYGLFPANYVE 52


>gnl|CDD|212962 cd12029, SH3_DLG3, Src Homology 3 domain of Disks Large homolog
          3.  DLG3, also called synapse-associated protein 102
          (SAP102), is a scaffolding protein that clusters at
          synapses and plays an important role in synaptic
          development and plasticity. Mutations in DLG3 cause
          midgestational embryonic lethality in mice and may be
          associated with nonsyndromic X-linked mental
          retardation in humans. It interacts with the NEDD4
          (neural precursor cell-expressed developmentally
          downregulated 4) family of ubiquitin ligases and
          promotes apical tight junction formation. DLG3 is a
          member of the MAGUK (membrane-associated guanylate
          kinase) protein family, which is characterized by the
          presence of a core of three domains: PDZ, SH3, and
          guanylate kinase (GuK). The GuK domain in MAGUK
          proteins is enzymatically inactive; instead, the domain
          mediates protein-protein interactions and associates
          intramolecularly with the SH3 domain. DLG3 contains
          three PDZ domains. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 67

 Score = 34.3 bits (78), Expect = 5e-04
 Identities = 21/56 (37%), Positives = 30/56 (53%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTD-----EDLSFRKGEHLEILNDTQGDWWLAR----SKATKQEGYIPS 50
          AL+DYD   D     + LSF  G+ L ++N +  +WW AR       ++Q G IPS
Sbjct: 7  ALFDYDRTRDSCLPSQGLSFSYGDILHVINASDDEWWQARLVTPHGESEQIGVIPS 62


>gnl|CDD|212814 cd11881, SH3_MYO7A, Src Homology 3 domain of Myosin VIIa and
          similar proteins.  Myo7A is an uncoventional myosin
          that is involved in organelle transport. It is required
          for sensory function in both Drosophila and mammals.
          Mutations in the Myo7A gene cause both syndromic
          deaf-blindness [Usher syndrome I (USH1)] and
          nonsyndromic (DFNB2 and DFNA11) deafness in humans. It
          contains an N-terminal motor domain, light
          chain-binding IQ motifs, a coiled-coil region for heavy
          chain dimerization, and a tail consisting of a pair of
          MyTH4-FERM tandems separated by a 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 = 64

 Score = 34.0 bits (78), Expect = 5e-04
 Identities = 22/59 (37%), Positives = 29/59 (49%), Gaps = 9/59 (15%)

Query: 3  VALYDYDARTDED--LSFRKGEHLEILNDTQGD------WWLARSKATKQEGYIPSNYV 53
          VAL DY   +D    LSF KG+ L IL+   G+      W   R+  T Q G  P++ V
Sbjct: 5  VALQDYPNPSDGSSFLSFAKGD-LIILDQDTGEQVMNSGWCNGRNDRTGQRGDFPADCV 62


>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 = 33.8 bits (77), Expect = 5e-04
 Identities = 19/53 (35%), Positives = 30/53 (56%), Gaps = 4/53 (7%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYV 53
          VA Y++ AR   +LS R+G+ + I +   GD  WW  + +   + G+ PS YV
Sbjct: 4  VARYNFAARDMRELSLREGDVVRIYSRIGGDQGWW--KGETNGRIGWFPSTYV 54


>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 = 33.8 bits (77), Expect = 5e-04
 Identities = 20/51 (39%), Positives = 31/51 (60%), Gaps = 3/51 (5%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDT-QGDWWLARSKATKQEGYIPSNYV 53
          A YD+ AR   +LS ++G+ ++ILN   Q  WW  R +   + G+ P+NYV
Sbjct: 4  ARYDFCARDRSELSLKEGDIIKILNKKGQQGWW--RGEIYGRVGWFPANYV 52


>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 = 33.6 bits (77), Expect = 5e-04
 Identities = 15/49 (30%), Positives = 28/49 (57%), Gaps = 1/49 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          ALYDY+A+ D+++S R G+ + ++    G  W    +    +G  P++Y
Sbjct: 4  ALYDYEAQGDDEISIRVGDRIAVIRGDDGSGW-TYGEINGVKGLFPTSY 51


>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 = 33.9 bits (77), Expect = 6e-04
 Identities = 15/50 (30%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A +++    +++LSF KG+ + +    +G WW        + G+ PSNYV
Sbjct: 4  AKFNFQQTNEDELSFSKGDVIHVTRVEEGGWW--EGTHNGRTGWFPSNYV 51


>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 = 33.8 bits (77), Expect = 6e-04
 Identities = 16/57 (28%), Positives = 31/57 (54%), Gaps = 3/57 (5%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPSNYVAK 55
          ++V++ DY+   +E   F++G  +E+L      WW  +        +G++PSNY+ K
Sbjct: 1  VYVSIADYEG-DEETAGFQEGVSMEVLEKNPNGWWYCQILDGVKPFKGWVPSNYLEK 56


>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 = 33.4 bits (76), Expect = 8e-04
 Identities = 19/53 (35%), Positives = 31/53 (58%), Gaps = 2/53 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          A+YD+ A+T ++LSF+KG+ + IL     +W+        + G  P +YV KL
Sbjct: 5  AVYDFKAQTSKELSFKKGDTVYILRKIDQNWYEGEHHG--RVGIFPISYVEKL 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 = 33.5 bits (76), Expect = 8e-04
 Identities = 15/54 (27%), Positives = 30/54 (55%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +  +Y Y AR  ++++  KG  +E++      WW  R +   +EG+ P++Y+ K
Sbjct: 3  YTVIYPYTARDQDEINLEKGAVVEVIQKNLEGWWKIRYQG--KEGWAPASYLKK 54


>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 = 33.3 bits (76), Expect = 8e-04
 Identities = 16/51 (31%), Positives = 31/51 (60%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA+Y+YDAR  ++LS + G+ + IL   +G +     +   ++G  P++Y+
Sbjct: 3  VAIYNYDARGPDELSLQIGDTVHILETYEGWYRGYTLRKKSKKGIFPASYI 53


>gnl|CDD|213019 cd12143, SH3_ARHGAP9, Src Homology 3 domain of Rho
          GTPase-activating protein 9 and similar proteins.  Rho
          GTPase-activating proteins (RhoGAPs or ARHGAPs) bind to
          Rho proteins and enhance the hydrolysis rates of bound
          GTP. ARHGAP9 functions as a GAP for Rac and Cdc42, but
          not for RhoA. It negatively regulates cell migration
          and adhesion. It also acts as a docking protein for the
          MAP kinases Erk2 and p38alpha, and may facilitate
          cross-talk between the Rho GTPase and MAPK pathways to
          control actin remodeling. It contains SH3, WW,
          Pleckstin homology (PH), and RhoGAP domains. SH3
          domains bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs; they play a role in the regulation of enzymes
          by intramolecular interactions, changing the
          subcellular localization of signal pathway components
          and mediate multiprotein complex assemblies.
          Length = 57

 Score = 33.4 bits (76), Expect = 9e-04
 Identities = 16/54 (29%), Positives = 26/54 (48%), Gaps = 5/54 (9%)

Query: 4  ALYDYDARTDE--DLSFRKGEHLEILNDTQGDWWLAR---SKATKQEGYIPSNY 52
          ALY Y     +   +S  +GE   +L  T  DWW  R   + +T +  ++P+ Y
Sbjct: 4  ALYAYQYTGADGRQVSIAEGERFLLLRKTNSDWWQVRRLEAPSTSRPLFVPATY 57


>gnl|CDD|212831 cd11898, SH3_SNX9, Src Homology 3 domain of Sorting nexin 9.
          Sorting nexin 9 (SNX9), also known as SH3PX1, is a
          cytosolic protein that interacts with proteins
          associated with clathrin-coated pits such as
          Cdc-42-associated tyrosine kinase 2 (ACK2). It binds
          class I polyproline sequences found in dynamin 1/2 and
          the WASP/N-WASP actin regulators. SNX9 is localized to
          plasma membrane endocytic sites and acts primarily in
          clathrin-mediated endocytosis. Its array of interacting
          partners suggests that SNX9 functions at the interface
          between endocytosis and actin cytoskeletal
          organization. SNXs are Phox homology (PX) domain
          containing proteins that are involved in regulating
          membrane traffic and protein sorting in the endosomal
          system. SNX9 also contains BAR and SH3 domains. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 57

 Score = 33.3 bits (76), Expect = 0.001
 Identities = 14/50 (28%), Positives = 28/50 (56%), Gaps = 1/50 (2%)

Query: 5  LYDYDART-DEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          LYD+ A   + +L+ ++GE + + N   G  W+    +  + G +P++YV
Sbjct: 5  LYDFAAEPGNNELTVKEGEIITVTNPNVGGGWIEAKNSQGERGLVPTDYV 54


>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 = 33.1 bits (76), Expect = 0.001
 Identities = 14/50 (28%), Positives = 27/50 (54%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY + A++ ++LS +KG+ + I      +W+        + G  P++YV
Sbjct: 4  ALYPFKAQSAKELSLKKGDIIYIRRQIDKNWYEGEHNG--RVGIFPASYV 51


>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 = 33.4 bits (76), Expect = 0.001
 Identities = 17/56 (30%), Positives = 26/56 (46%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPS 50
          A +DYD + D         L F+ G+ ++I+N    +WW  R      +  G IPS
Sbjct: 4  AQFDYDPKKDNLIPCKEAGLKFQTGDIIQIINKDDSNWWQGRVEGSGEESAGLIPS 59


>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 = 33.1 bits (75), Expect = 0.001
 Identities = 16/48 (33%), Positives = 24/48 (50%), Gaps = 2/48 (4%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          + Y A  +++LS  KG  + ++      WW  R     Q G+ PSNYV
Sbjct: 7  FAYVAEREDELSLVKGSRVTVMEKCSDGWW--RGSYNGQIGWFPSNYV 52


>gnl|CDD|212744 cd11810, SH3_RUSC1_like, Src homology 3 domain of RUN and SH3
          domain-containing proteins 1 and 2.  RUSC1 and RUSC2,
          that were originally characterized in silico. They are
          adaptor proteins consisting of RUN, leucine zipper, and
          SH3 domains. RUSC1, also called NESCA (New molecule
          containing SH3 at the carboxy-terminus), is highly
          expressed in the brain and is translocated to the
          nuclear membrane from the cytoplasm upon stimulation
          with neurotrophin. It plays a role in facilitating
          neurotrophin-dependent neurite outgrowth. It also
          interacts with NEMO (or IKKgamma) and may function in
          NEMO-mediated activation of NF-kB. RUSC2, also called
          Iporin, is expressed ubiquitously with highest amounts
          in the brain and testis. It interacts with the small
          GTPase Rab1 and the Golgi matrix protein GM130, and may
          function in linking GTPases to certain intracellular
          signaling pathways. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 50

 Score = 32.8 bits (75), Expect = 0.001
 Identities = 15/49 (30%), Positives = 22/49 (44%), Gaps = 2/49 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          AL  + A     LSFRKG+ L ++     DW          +G +P +Y
Sbjct: 4  ALCHHVATDSGQLSFRKGDILRVIARVDDDW--LLCTRGSTKGLVPLSY 50


>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 = 32.9 bits (75), Expect = 0.001
 Identities = 15/55 (27%), Positives = 31/55 (56%), Gaps = 2/55 (3%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +++ +  Y A  +++L+  +GE +E+++     WW+ R    +  GY PS Y+ K
Sbjct: 1  LYITIKAYTAVEEDELTLLEGEAIEVIHKLLDGWWVVRKG--EVTGYFPSMYLQK 53


>gnl|CDD|212915 cd11982, SH3_Shank1, Src homology 3 domain of SH3 and multiple
          ankyrin repeat domains protein 1.  Shank1, also called
          SSTRIP (Somatostatin receptor-interacting protein), is
          a brain-specific protein that plays a role in the
          construction of postsynaptic density (PSD) and the
          maturation of dendritic spines. Mice deficient in
          Shank1 show altered PSD composition, thinner PSDs,
          smaller dendritic spines, and weaker basal synaptic
          transmission, although synaptic plasticity is normal.
          They show increased anxiety and impaired fear memory,
          but also show better spatial learning. Shank proteins
          carry scaffolding functions through multiple sites of
          protein-protein interaction in its domain architecture,
          including ankyrin (ANK) repeats, a long proline rich
          region, as well as SH3, PDZ, and SAM domains. The SH3
          domain of Shank binds GRIP, a scaffold protein that
          binds AMPA receptors and Eph receptors/ligands. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 52

 Score = 33.1 bits (75), Expect = 0.001
 Identities = 15/52 (28%), Positives = 32/52 (61%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          F+A+  Y ++ + ++S  KGE +++L+  +G +W  + K   + G+ PS+ V
Sbjct: 3  FMAVKPYQSQAEGEISLSKGEKIKVLSVGEGGFWEGQVKG--RVGWFPSDCV 52


>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 = 32.8 bits (75), Expect = 0.001
 Identities = 14/51 (27%), Positives = 29/51 (56%), Gaps = 4/51 (7%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYV 53
          L+DY+    ++L+ +KG+ +E+++    D  WW    +   + G+ P N+V
Sbjct: 5  LFDYNPVAPDELALKKGDVIEVISKETEDEGWW--EGELNGRRGFFPDNFV 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 = 33.1 bits (75), Expect = 0.001
 Identities = 19/56 (33%), Positives = 31/56 (55%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTD-----EDLSFRKGEHLEILNDTQGDWWLAR----SKATKQEGYIPS 50
          A++DY+   D     + LSFR G+ L ++N +  +WW AR       +++ G IPS
Sbjct: 10 AMFDYEKSKDSGLPSQGLSFRYGDILHVINASDDEWWQARRVTPDGDSEEMGVIPS 65


>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 = 32.6 bits (74), Expect = 0.001
 Identities = 13/52 (25%), Positives = 28/52 (53%), Gaps = 2/52 (3%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          L++Y  + +++L  + G+ ++I  + +  WW        + G  PSN+V +L
Sbjct: 6  LFEYVPQNEDELELKVGDIIDINEEVEEGWW--SGTLNGKSGLFPSNFVKEL 55


>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 = 32.7 bits (74), Expect = 0.001
 Identities = 16/50 (32%), Positives = 26/50 (52%), Gaps = 2/50 (4%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ++Y A  +++LS  KG  + ++      WW  R     Q G+ PSNYV +
Sbjct: 8  FNYTAEREDELSLVKGTKVIVMEKCSDGWW--RGSYNGQVGWFPSNYVTE 55


>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 = 32.7 bits (74), Expect = 0.002
 Identities = 20/56 (35%), Positives = 29/56 (51%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTD-----EDLSFRKGEHLEILNDTQGDWWLARSKATKQE----GYIPS 50
          AL+DYD   D     + L+F+ G+ L ++N +  +WW AR      E    G IPS
Sbjct: 7  ALFDYDKTKDSGLPSQGLNFKFGDILHVVNASDDEWWQARQVTADGESEEIGVIPS 62


>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 = 32.6 bits (74), Expect = 0.002
 Identities = 18/52 (34%), Positives = 24/52 (46%), Gaps = 7/52 (13%)

Query: 6  YDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPS 50
          +DYD  +D         L FR G+ L+I+N    +WW A        G IPS
Sbjct: 6  FDYDPSSDSLIPCKEAGLKFRAGDLLQIVNQEDPNWWQACHVEGGSAGLIPS 57


>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 = 32.4 bits (73), Expect = 0.002
 Identities = 10/52 (19%), Positives = 32/52 (61%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +V + +Y+ + + ++S + GE ++++   +  WW   +   +++G++P+ Y+
Sbjct: 2  YVVVSNYEKQENSEISLQAGEVVDVIEKNESGWWFVST--AEEQGWVPATYL 51


>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 = 32.4 bits (74), Expect = 0.002
 Identities = 18/53 (33%), Positives = 26/53 (49%), Gaps = 7/53 (13%)

Query: 4  ALYDYDARTDEDLSFRKGE---HLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYDY A  D ++SF  G+    +E +++    WW          G  P+NYV
Sbjct: 4  ALYDYQAADDTEISFDPGDIITDIEQIDEG---WWRGTGPDGTY-GLFPANYV 52


>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 = 32.0 bits (73), Expect = 0.002
 Identities = 13/51 (25%), Positives = 28/51 (54%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA +D++   +++LSF +G+ + +      +W  A+ +   + G  P N+V
Sbjct: 3  VARFDFEGEQEDELSFSEGDVITLKEYVGEEW--AKGELNGKIGIFPLNFV 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 = 32.1 bits (73), Expect = 0.002
 Identities = 16/56 (28%), Positives = 31/56 (55%), Gaps = 1/56 (1%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKLK 57
          ++  YDYDA  +++L+ R GE +  +   + + WL   +   + G  P N+V ++K
Sbjct: 2  YIVEYDYDAVHEDELTIRVGEIIRNVKKLEEEGWL-EGELNGRRGMFPDNFVKEIK 56


>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 = 32.4 bits (74), Expect = 0.003
 Identities = 14/41 (34%), Positives = 21/41 (51%), Gaps = 7/41 (17%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLA 37
          A +DYD   D         LSF+KG+ L +++    +WW A
Sbjct: 4  AHFDYDPEDDPYIPCRELGLSFQKGDILHVISQEDPNWWQA 44


>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 = 32.4 bits (73), Expect = 0.003
 Identities = 13/50 (26%), Positives = 32/50 (64%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A++D+    + +L+F+ G+ +++L+ +  DWW    +   +EG+ P+++V
Sbjct: 9  AVWDHVTMANRELAFKAGDVIKVLDASNKDWWWG--QIDDEEGWFPASFV 56


>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 = 31.9 bits (73), Expect = 0.003
 Identities = 18/53 (33%), Positives = 31/53 (58%), Gaps = 2/53 (3%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPSNYVAK 55
          ALY ++AR  +++SF+ G+ +++      +  WLA     K  G+ P+NYV K
Sbjct: 4  ALYAFEARNPDEISFQPGDIIQVDESQVAEPGWLAGELKGK-TGWFPANYVEK 55


>gnl|CDD|212794 cd11860, SH3_DLG5, Src homology 3 domain of Disks Large homolog
          5.  DLG5 is a multifunctional scaffold protein that is
          located at sites of cell-cell contact and is involved
          in the maintenance of cell shape and polarity.
          Mutations in the DLG5 gene are associated with Crohn's
          disease (CD) and inflammatory bowel disease (IBD). DLG5
          is a member of the MAGUK (membrane-associated guanylate
          kinase) protein family, which is characterized by the
          presence of a core of three domains: PDZ, SH3, and
          guanylate kinase (GuK). The GuK domain in MAGUK
          proteins is enzymatically inactive; instead, the domain
          mediates protein-protein interactions and associates
          intramolecularly with the SH3 domain. DLG5 contains 4
          PDZ domains as well as an N-terminal domain of unknown
          function. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 63

 Score = 32.3 bits (74), Expect = 0.003
 Identities = 20/57 (35%), Positives = 30/57 (52%), Gaps = 7/57 (12%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEI----LNDTQGDW--WLARSKATKQE-GYIPSNYV 53
          AL+D  A  +++LSF+K + L +     N   G W  WL   +  K++ G IPS Y 
Sbjct: 4  ALFDRSAENEDELSFKKDDILYVDNTMFNGVFGQWRAWLVDEEGRKRKCGIIPSKYK 60


>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 = 31.6 bits (72), Expect = 0.003
 Identities = 14/56 (25%), Positives = 30/56 (53%), Gaps = 6/56 (10%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILN---DTQGDWWLARSKATKQEGYIPSNYV 53
           ++ L+D      ++LSF++G+ + I++   D+ G WW+         G +P +Y+
Sbjct: 1  WYMGLWDCSGNEPDELSFKRGDLIYIISKEYDSFG-WWVGELNGKV--GLVPKDYL 53


>gnl|CDD|212927 cd11994, SH3_Intersectin2_4, Fourth Src homology 3 domain (or
          SH3D) of Intersectin-2.  Intersectin-2 (ITSN2) is an
          adaptor protein that functions in exo- and endocytosis,
          actin cytoskeletal reorganization, and signal
          transduction. It plays a role in clathrin-coated pit
          (CCP) formation. It binds to many proteins through its
          multidomain structure and facilitate the assembly of
          multimeric complexes. ITSN2 also functions as a
          specific GEF for Cdc42 activation in epithelial
          morphogenesis, and is required in mitotic spindle
          orientation. It exists in alternatively spliced short
          and long isoforms. The short isoform contains two Eps15
          homology domains (EH1 and EH2), a coiled-coil region
          and five SH3 domains (SH3A-E), while the long isoform,
          in addition, contains RhoGEF (also called
          Dbl-homologous or DH), Pleckstrin homology (PH) and C2
          domains. The fourth SH3 domain (or SH3D) of ITSN2 is
          expected to bind protein partners, similar to ITSN1
          which has been shown to bind SHIP2, Numb, CdGAP, and
          N-WASP. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 59

 Score = 31.8 bits (72), Expect = 0.003
 Identities = 19/53 (35%), Positives = 27/53 (50%), Gaps = 5/53 (9%)

Query: 8  YDARTDEDLSFRKGEHLEILNDTQGDWWL----ARSKATKQEGYIPSNYVAKL 56
          Y A   E LS   G+ + IL      WWL    AR K  +Q+G+ P+++V  L
Sbjct: 8  YVASGVEQLSLSPGQLILILKKNSSGWWLGELQARGK-KRQKGWFPASHVKLL 59


>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 = 31.6 bits (71), Expect = 0.005
 Identities = 15/50 (30%), Positives = 25/50 (50%), Gaps = 3/50 (6%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL  + A+ D  L+F K + + +L + Q +WW          G+ P +YV
Sbjct: 4  ALCSWTAKKDNHLNFSKNDIITVL-EQQENWWFGEVHG--GRGWFPKSYV 50


>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 = 31.6 bits (71), Expect = 0.005
 Identities = 14/54 (25%), Positives = 28/54 (51%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +  + ++ +   + +SFR G+  E++    G WW  +      EG+ PS+Y+ K
Sbjct: 3  YYTIAEFQSCISDGISFRGGQKAEVIEKNSGGWWYVQIGEK--EGWAPSSYIDK 54


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

 Score = 31.1 bits (70), Expect = 0.005
 Identities = 14/50 (28%), Positives = 26/50 (52%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALYD+ +    ++S R+ E L + ++   + WL    +    G  P++YV
Sbjct: 4  ALYDFRSENPGEISLREHEVLSLCSEQDIEGWLEGVNSRGDRGLFPASYV 53


>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 = 31.4 bits (71), Expect = 0.006
 Identities = 17/52 (32%), Positives = 29/52 (55%), Gaps = 7/52 (13%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN----DTQGDWWLARSKATKQEGYIPSN 51
          ALYD  A   ++L+FR+G+ L +L      ++G WW  +     ++G  P+N
Sbjct: 5  ALYDNKADCSDELAFRRGDILTVLEQNVPGSEG-WW--KCLLHGRQGLAPAN 53


>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 = 31.1 bits (70), Expect = 0.006
 Identities = 14/50 (28%), Positives = 25/50 (50%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY+Y+ +   DL F KG+ + +      +W+          G+ P+N+V
Sbjct: 5  ALYNYEGKEPGDLKFSKGDIIILRRQVDENWYHGEVNGI--HGFFPTNFV 52


>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 = 31.1 bits (70), Expect = 0.007
 Identities = 19/54 (35%), Positives = 29/54 (53%), Gaps = 3/54 (5%)

Query: 1  IFVALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPSNYV 53
          I +A YD+ AR   +LS  KG+ ++I      + WW  R +   + G+ PS YV
Sbjct: 2  IAIARYDFCARDMRELSLLKGDVVKIYTKMSTNGWW--RGEVNGRVGWFPSTYV 53


>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 = 31.0 bits (70), Expect = 0.007
 Identities = 19/55 (34%), Positives = 31/55 (56%), Gaps = 2/55 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPSNYVAK 55
          + ALY ++AR  +++SF  G+ +++   T G+  WL  S      G+ P NYV K
Sbjct: 4  YRALYPFEARNHDEMSFNAGDIIQVDEKTVGEPGWLYGS-FQGNFGWFPCNYVEK 57


>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 = 30.5 bits (69), Expect = 0.010
 Identities = 13/54 (24%), Positives = 27/54 (50%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          ++    Y A  ++++ F  G  +E++      WW  R +   +EG+ P+ Y+ K
Sbjct: 3  YITTQAYKAENEDEIGFETGVVVEVIQKNLDGWWKIRYQG--KEGWAPATYLKK 54


>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 = 30.6 bits (69), Expect = 0.010
 Identities = 12/49 (24%), Positives = 24/49 (48%), Gaps = 1/49 (2%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPS 50
          V   D+      +L+F KG+ + I+   +   W+ AR   + +EG + +
Sbjct: 5  VTKKDHTKPKPGELAFHKGDIVTIVETCERKGWYRARHNTSGEEGLVAA 53


>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 = 30.8 bits (69), Expect = 0.011
 Identities = 19/56 (33%), Positives = 26/56 (46%), Gaps = 8/56 (14%)

Query: 6  YDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARS-KATKQEGYIPSNYV 53
          +DY+   D         L F KGE L+I+N    +WW A   K     G IPS ++
Sbjct: 6  FDYNPYNDNLIPCKEAGLKFSKGEILQIVNREDPNWWQASHVKEGGSAGLIPSQFL 61


>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 = 30.8 bits (70), Expect = 0.011
 Identities = 16/58 (27%), Positives = 30/58 (51%), Gaps = 5/58 (8%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN----DTQGDWWLARSK-ATKQEGYIPSNYVAKL 56
          A +DY A   ++L+F KG+ + ++     + Q + WL   K +T   G  P N+  ++
Sbjct: 7  ATHDYTAEDTDELTFEKGDVILVIPFDDPEEQDEGWLMGVKESTGCRGVFPENFTERI 64


>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 = 30.3 bits (68), Expect = 0.012
 Identities = 18/50 (36%), Positives = 24/50 (48%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL  + A     LSF KG+ L++L+   GDW   R       G +P  YV
Sbjct: 4  ALCHHIATEPGQLSFNKGDILQVLSRADGDW--LRCSLGPDSGLVPIAYV 51


>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 = 30.4 bits (69), Expect = 0.013
 Identities = 13/50 (26%), Positives = 22/50 (44%), Gaps = 3/50 (6%)

Query: 7  DYDARTDEDLSFRKGEHLEILNDTQGDWW---LARSKATKQEGYIPSNYV 53
           + A  +  LS   G+ + +   +   WW   L      +Q G+ P+NYV
Sbjct: 7  PFTATAENQLSLAVGQLVLVRKKSPSGWWEGELQARGKKRQIGWFPANYV 56


>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 = 30.3 bits (68), Expect = 0.015
 Identities = 15/52 (28%), Positives = 25/52 (48%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ++    Y    D ++SF  G  +E+L   +  WW  R      EG+ PS+Y+
Sbjct: 2  YMTTSAYQKVQDSEISFPAGVEVEVLEKQESGWWYVRFGEL--EGWAPSHYL 51


>gnl|CDD|212997 cd12064, SH3_GRAF, Src Homology 3 domain of GTPase Regulator
          Associated with Focal adhesion kinase.  GRAF, also
          called Rho GTPase activating protein 26 (ARHGAP26),
          Oligophrenin-1-like (OPHN1L) or GRAF1, is a GAP with
          activity towards RhoA and Cdc42 and is only weakly
          active towards Rac1. It influences Rho-mediated
          cytoskeletal rearrangements and binds focal adhesion
          kinase (FAK), which is a critical component of integrin
          signaling. It is essential for the major
          clathrin-independent endocytic pathway mediated by
          pleiomorphic membranes. GRAF contains an N-terminal BAR
          domain, followed by a Pleckstrin homology (PH) domain,
          a Rho GAP domain, and a C-terminal SH3 domain. The SH3
          domain of GRAF binds PKNbeta, a target of the small
          GTPase Rho. SH3 domains bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs; they play a role in the regulation of
          enzymes by intramolecular interactions, changing the
          subcellular localization of signal pathway components
          and mediate multiprotein complex assemblies.
          Length = 56

 Score = 30.1 bits (67), Expect = 0.015
 Identities = 19/50 (38%), Positives = 25/50 (50%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY   A  D +LSF  G   + ++ +Q   WL  +   K  G IP NYV
Sbjct: 5  ALYACKAEHDSELSFTAGTVFDNVHPSQEPGWLEGTLNGKT-GLIPENYV 53


>gnl|CDD|212922 cd11989, SH3_Intersectin1_2, Second Src homology 3 domain (or
          SH3B) of Intersectin-1.  Intersectin-1 (ITSN1) is an
          adaptor protein that functions in exo- and endocytosis,
          actin cytoskeletal reorganization, and signal
          transduction. It plays a role in clathrin-coated pit
          (CCP) formation. It binds to many proteins through its
          multidomain structure and facilitate the assembly of
          multimeric complexes. ITSN1 localizes in membranous
          organelles, CCPs, the Golgi complex, and may be
          involved in the cell membrane trafficking system. It
          exists in alternatively spliced short and long
          isoforms. The short isoform contains two Eps15 homology
          domains (EH1 and EH2), a coiled-coil region and five
          SH3 domains (SH3A-E), while the long isoform, in
          addition, contains RhoGEF (also called Dbl-homologous
          or DH), Pleckstrin homology (PH) and C2 domains. The
          second SH3 domain (or SH3B) of ITSN1 has been shown to
          bind WNK and CdGAP. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 52

 Score = 30.1 bits (67), Expect = 0.015
 Identities = 17/50 (34%), Positives = 28/50 (56%), Gaps = 3/50 (6%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY + A+ D  L+F K + + +L + Q  WW    +   Q+G+ P +YV
Sbjct: 4  ALYPWRAKKDNHLNFNKNDVITVL-EQQDMWWFGEVQG--QKGWFPKSYV 50


>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 = 30.0 bits (67), Expect = 0.017
 Identities = 16/51 (31%), Positives = 24/51 (47%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          VA+YDY    D++LSF +G  + ++      W+          G  P NYV
Sbjct: 3  VAIYDYSKDKDDELSFMEGAIIYVIKKNDDGWYEGVCNGVT--GLFPGNYV 51


>gnl|CDD|213010 cd12077, SH3_Tks5_2, Second Src homology 3 domain of Tyrosine
          kinase substrate with five SH3 domains.  Tks5, also
          called SH3 and PX domain-containing protein 2A
          (SH3PXD2A) or Five SH (FISH), is a scaffolding protein
          and Src substrate that is localized in podosomes, which
          are electron-dense structures found in Src-transformed
          fibroblasts, osteoclasts, macrophages, and some
          invasive cancer cells. It binds and regulates some
          members of the ADAMs family of transmembrane
          metalloproteases, which function as sheddases and
          mediators of cell and matrix interactions. It is
          required for podosome formation, degradation of the
          extracellular matrix, and cancer cell invasion. Tks5
          contains an N-terminal Phox homology (PX) domain and
          five SH3 domains. This model characterizes the second
          SH3 domain of Tks5. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 54

 Score = 30.0 bits (67), Expect = 0.017
 Identities = 14/54 (25%), Positives = 29/54 (53%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +V +  Y ++  +++ F KG  +E++      WW  R     +EG+ P++Y+ K
Sbjct: 3  YVTVQPYTSQGKDEIGFEKGVTVEVIQKNLEGWWYIRYLG--KEGWAPASYLKK 54


>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 = 30.0 bits (68), Expect = 0.018
 Identities = 18/60 (30%), Positives = 30/60 (50%), Gaps = 8/60 (13%)

Query: 1  IFVALYDYDAR-------TDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
            VAL+DYD R        + +LSFR G+ + +  +   D +    +   Q G +PSN++
Sbjct: 1  RMVALFDYDPRESSPNVDAEVELSFRAGDIITVFGEMDEDGFY-YGELNGQRGLVPSNFL 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 = 30.0 bits (67), Expect = 0.021
 Identities = 13/50 (26%), Positives = 29/50 (58%), Gaps = 1/50 (2%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKA-TKQEGYIPSNYV 53
          +YD  A  D++L+F +GE + +  +   +WW+   +   +++G  P ++V
Sbjct: 5  IYDCQADNDDELTFVEGEVIIVTGEEDQEWWIGHIEGQPERKGVFPVSFV 54


>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 = 29.5 bits (66), Expect = 0.026
 Identities = 13/48 (27%), Positives = 24/48 (50%), Gaps = 2/48 (4%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +DY A+ +++L+   G+ +  +    G WW    K  +  G  P N+V
Sbjct: 6  FDYKAQHEDELTITVGDIITKIKKDDGGWWEGEIKGRR--GLFPDNFV 51


>gnl|CDD|213003 cd12070, SH3_ARHGAP12, Src Homology 3 domain of Rho
          GTPase-activating protein 12.  Rho GTPase-activating
          proteins (RhoGAPs or ARHGAPs) bind to Rho proteins and
          enhance the hydrolysis rates of bound GTP. ARHGAP12 has
          been shown to display GAP activity towards Rac1. It
          plays a role in regulating hepatocyte growth factor
          (HGF)-driven cell growth and invasiveness. It contains
          SH3, WW, Pleckstin homology (PH), and RhoGAP domains.
          SH3 domains bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs; they play a role in the regulation of enzymes
          by intramolecular interactions, changing the
          subcellular localization of signal pathway components
          and mediate multiprotein complex assemblies.
          Length = 60

 Score = 29.6 bits (66), Expect = 0.026
 Identities = 15/48 (31%), Positives = 26/48 (54%), Gaps = 1/48 (2%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          YDY+A+ D  +  ++GE   ++  T  DWW  +     +  Y+P+ YV
Sbjct: 9  YDYEAK-DRKIVIKQGERYILVKKTNDDWWQVKKDENSKPFYVPAQYV 55


>gnl|CDD|212805 cd11872, SH3_DOCK_AB, Src Homology 3 domain of Class A and B
          Dedicator of Cytokinesis proteins.  DOCK proteins are
          atypical guanine nucleotide exchange factors (GEFs)
          that lack the conventional Dbl homology (DH) domain.
          They are divided into four classes (A-D) based on
          sequence similarity and domain architecture: class A
          includes Dock1, 2 and 5; class B includes Dock3 and 4;
          class C includes Dock6, 7, and 8; and class D includes
          Dock9, 10 and 11. 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. This subfamily includes only Class A and
          B DOCKs, which also contain an SH3 domain at the
          N-terminal region and a PxxP motif at the C-terminus.
          Class A/B DOCKs are mostly specific GEFs for Rac,
          except Dock4 which activates the Ras family GTPase
          Rap1, probably indirectly through interaction with Rap
          regulatory proteins. The SH3 domain of class A/B DOCKs
          have been shown to bind Elmo, a scaffold protein that
          promotes GEF activity of DOCKs by releasing DHR-2
          autoinhibition by the intramolecular 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 = 29.5 bits (67), Expect = 0.027
 Identities = 15/52 (28%), Positives = 27/52 (51%), Gaps = 2/52 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATK-QEGYIPSNYV 53
          VA+Y++    +  LS + G+ ++IL +    W+   S   K  +G  P +YV
Sbjct: 3  VAIYNFQGDGEHQLSLQVGDTVQIL-EECEGWYRGFSLRNKSLKGIFPKSYV 53


>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 = 29.5 bits (66), Expect = 0.030
 Identities = 13/54 (24%), Positives = 29/54 (53%), Gaps = 4/54 (7%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILNDTQGD--WWLARSKATKQEGYIPSNYVAKL 56
          L+ Y+A+ +++L+ ++G+ + +++    D  WW       +  G  P N+V  L
Sbjct: 5  LFPYEAQNEDELTIKEGDIVTLISKDCIDAGWWEGELNGRR--GVFPDNFVKLL 56


>gnl|CDD|213002 cd12069, SH3_ARHGAP27, Src Homology 3 domain of Rho
          GTPase-activating protein 27.  Rho GTPase-activating
          proteins (RhoGAPs or ARHGAPs) bind to Rho proteins and
          enhance the hydrolysis rates of bound GTP. ARHGAP27,
          also called CAMGAP1, shows GAP activity towards Rac1
          and Cdc42. It binds the adaptor protein CIN85 and may
          play a role in clathrin-mediated endocytosis. It
          contains SH3, WW, Pleckstin homology (PH), and RhoGAP
          domains. SH3 domains bind to proline-rich ligands with
          moderate affinity and selectivity, preferentially to
          PxxP motifs; they play a role in the regulation of
          enzymes by intramolecular interactions, changing the
          subcellular localization of signal pathway components
          and mediate multiprotein complex assemblies.
          Length = 57

 Score = 29.4 bits (66), Expect = 0.030
 Identities = 13/48 (27%), Positives = 21/48 (43%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ++Y  +    +S +  E   +L  T   WW  R     +  YIP+ YV
Sbjct: 8  FEYTGKDGRLVSIKPNERYILLRRTNEHWWHVRRDKGTRPFYIPAKYV 55


>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 = 29.2 bits (65), Expect = 0.033
 Identities = 12/50 (24%), Positives = 32/50 (64%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A+ DY+  +  +++ + G+ +E++  ++  WW  + KA +  G++P++Y+
Sbjct: 4  AIADYEKSSKSEMALKTGDVVEVVEKSENGWWFCQLKAKR--GWVPASYL 51


>gnl|CDD|212787 cd11853, SH3_Kalirin_2, Second Src homology 3 domain of the
          RhoGEF kinase, Kalirin.  Kalirin, also called Duo,
          Duet, or TRAD, is a large neuronal dual Rho guanine
          nucleotide exchange factor (RhoGEF) that activates
          Rac1, RhoA, and RhoG using two RhoGEF domains. Kalirin
          exists in many isoforms generated by alternative
          splicing and the use of multiple promoters; the major
          isoforms are kalirin-7, -9, and -12, which differ at
          their C-terminal ends. Kalirin-12, the longest isoform,
          contains an N-terminal Sec14p domain, spectrin-like
          repeats, two RhoGEF domains, two SH3 domains, as well
          as Ig, FNIII, and kinase domains at the C-terminal end.
          Kalirin-7 contains only a single RhoGEF domain and does
          not contain an SH3 domain. Kalirin, through its many
          isoforms, interacts with many different proteins and is
          able to localize to different locations within the
          cell. It influences neurite initiation, axon growth,
          dendritic morphogenesis, vesicle trafficking, neuronal
          maintenance, and neurodegeneration. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 59

 Score = 29.3 bits (66), Expect = 0.035
 Identities = 16/47 (34%), Positives = 26/47 (55%), Gaps = 4/47 (8%)

Query: 7  DYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQ----EGYIP 49
          DY A  ++++   +GE ++IL   Q + +L    AT Q    EG+IP
Sbjct: 7  DYYALKEDEICVSQGEVVQILAANQQNMFLVYRPATDQSPAAEGWIP 53


>gnl|CDD|212725 cd11791, SH3_UBASH3, Src homology 3 domain of
          Ubiquitin-associated and SH3 domain-containing
          proteins, also called TULA (T cell Ubiquitin LigAnd)
          family of proteins.  UBASH3 or TULA proteins are also
          referred to as Suppressor of T cell receptor Signaling
          (STS) proteins. They contain an N-terminal UBA domain,
          a central SH3 domain, and a C-terminal histidine
          phosphatase domain. They bind c-Cbl through the SH3
          domain and to ubiquitin via UBA. In some vertebrates,
          there are two TULA family proteins, called UBASH3A
          (also called TULA or STS-2) and UBASH3B (also called
          TULA-2 or STS-1), which show partly overlapping as well
          as distinct functions. UBASH3B is widely expressed
          while UBASH3A is only found in lymphoid cells. UBASH3A
          facilitates apoptosis induced in T cells through its
          interaction with the apoptosis-inducing factor AIF.
          UBASH3B is an active phosphatase while UBASH3A is not.
          SH3 domains are protein interaction domains that bind
          to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 59

 Score = 29.2 bits (66), Expect = 0.038
 Identities = 13/56 (23%), Positives = 23/56 (41%), Gaps = 4/56 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD----WWLARSKATKQEGYIPSNYVAK 55
           LY Y  + +++L    G+++ +  +        W    S  T   G +P NY  K
Sbjct: 4  VLYPYTPQEEDELELVPGDYIYVSPEELDSSSDGWVEGTSWLTGCSGLLPENYTEK 59


>gnl|CDD|212947 cd12014, SH3_RIM-BP_1, First Src homology 3 domain of
          Rab3-interacting molecules (RIMs) binding proteins.
          RIMs binding proteins (RBPs, RIM-BPs) associate with
          calcium channels present in photoreceptors, neurons,
          and hair cells; they interact simultaneously with
          specific calcium channel subunits, and active zone
          proteins, RIM1 and RIM2. RIMs are part of the matrix at
          the presynaptic active zone and are associated with
          synaptic vesicles through their interaction with the
          small GTPase Rab3. RIM-BPs play a role in regulating
          synaptic transmission by serving as adaptors and
          linking calcium channels with the synaptic vesicle
          release machinery. RIM-BPs contain three SH3 domains
          and two to three fibronectin III repeats. Invertebrates
          contain one, while vertebrates contain at least two
          RIM-BPs, RIM-BP1 and RIM-BP2. RIM-BP1 is also called
          peripheral-type benzodiazapine receptor associated
          protein 1 (PRAX-1). Mammals contain a third protein,
          RIM-BP3. RIM-BP1 and RIM-BP2 are predominantly
          expressed in the brain where they display overlapping
          but distinct expression patterns, while RIM-BP3 is
          almost exclusively expressed in the testis and is
          essential in spermiogenesis. The SH3 domains of RIM-BPs
          bind to the PxxP motifs of RIM1, RIM2, and L-type
          (alpha1D) and N-type (alpha1B) calcium channel
          subunits. SH3 domains are protein interaction domains
          that bind to proline-rich ligands with moderate
          affinity and selectivity. They play versatile and
          diverse roles in the cell including the regulation of
          enzymes, changing the subcellular localization of
          signaling pathway components, and mediating the
          formation of multiprotein complex assemblies.
          Length = 62

 Score = 29.2 bits (66), Expect = 0.038
 Identities = 15/62 (24%), Positives = 27/62 (43%), Gaps = 7/62 (11%)

Query: 1  IFVALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          +FVA Y Y+   D        +L    G+++ +  D   D +        + G +PSN+V
Sbjct: 1  VFVARYSYNPLRDSPNENPEAELPLNAGDYVYVYGDMDEDGFYEGELLDGRRGLVPSNFV 60

Query: 54 AK 55
           +
Sbjct: 61 ER 62


>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 = 29.1 bits (65), Expect = 0.044
 Identities = 13/50 (26%), Positives = 25/50 (50%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          ALY Y+ +   DL F KG+ + +      +W+          G++P++Y+
Sbjct: 5  ALYSYEGKEPGDLKFNKGDIIILRRKVDENWYHGELNGCH--GFLPASYI 52


>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 = 28.6 bits (64), Expect = 0.053
 Identities = 13/49 (26%), Positives = 24/49 (48%), Gaps = 2/49 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          ALYD+    +++LSF+ G+ +  L     +W     +   + G  P N+
Sbjct: 4  ALYDFTGENEDELSFKAGDIITELESIDEEWMSGELRG--KSGIFPKNF 50


>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 = 28.4 bits (64), Expect = 0.066
 Identities = 14/51 (27%), Positives = 22/51 (43%), Gaps = 4/51 (7%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEI--LNDTQGDWWLARSKATKQEGYIPSNY 52
           LYDYDA    +LS    E + +  L     D+ +    + +  G +P  Y
Sbjct: 4  VLYDYDAEDSTELSLLADEVITVYELPGMDEDYMMGERGSQR--GKVPVAY 52


>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 = 28.4 bits (64), Expect = 0.067
 Identities = 18/54 (33%), Positives = 27/54 (50%), Gaps = 9/54 (16%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDT--QG--DWWLA----RSKATKQEGYIPSN 51
          +DY+     +LSF+KGE   ++ DT  QG    W A    R+    + G IP+ 
Sbjct: 6  FDYEKPAKGELSFKKGEVFHVV-DTLYQGTVGSWQAVRVGRNHQELERGVIPNK 58


>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 = 28.2 bits (63), Expect = 0.070
 Identities = 15/51 (29%), Positives = 24/51 (47%), Gaps = 3/51 (5%)

Query: 4  ALYDYDA-RTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
           LY +   +  + LSF  GE + +L    G WW       +  G+ P++YV
Sbjct: 4  TLYAFTGEQHQQGLSFEAGELIRVLQAPDGGWWEGEKDGLR--GWFPASYV 52


>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 = 28.2 bits (63), Expect = 0.088
 Identities = 13/50 (26%), Positives = 26/50 (52%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          AL D++   D++L FRK + + I++      W+   +     G+ P+ +V
Sbjct: 4  ALLDFERHDDDELGFRKNDIITIISQKDEHCWVG--ELNGLRGWFPAKFV 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 = 28.1 bits (62), Expect = 0.089
 Identities = 9/49 (18%), Positives = 26/49 (53%), Gaps = 2/49 (4%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPS 50
          +V + +Y  +   ++S   G+ ++I+   +  WW   +    ++G++P+
Sbjct: 3  YVVVANYQKQESSEISLYVGQVVDIIEKNESGWWFVST--ADEQGWVPA 49


>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 = 28.1 bits (62), Expect = 0.096
 Identities = 15/54 (27%), Positives = 26/54 (48%), Gaps = 2/54 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKL 56
          VA+YDY    +++LSF++G  + ++      W+          G  P NYV  +
Sbjct: 6  VAIYDYTKDKEDELSFQEGAIIYVIKKNDDGWYEGVMNGVT--GLFPGNYVESI 57


>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 = 28.0 bits (62), Expect = 0.098
 Identities = 14/38 (36%), Positives = 21/38 (55%), Gaps = 1/38 (2%)

Query: 16 LSFRKGEHLEILNDTQGDWWL-ARSKATKQEGYIPSNY 52
          LSF +G+ + +L   + D WL      TK  G+ PS+Y
Sbjct: 18 LSFAQGDVITLLIPEEKDGWLYGEHDTTKARGWFPSSY 55


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

 Score = 28.3 bits (63), Expect = 0.10
 Identities = 17/56 (30%), Positives = 29/56 (51%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLARSKATK--QEGYIPS 50
          A ++YD   D+        + FR G+ L+I++    +WW A+ + +K    G IPS
Sbjct: 4  AQFEYDPLKDDLIPCKQAGIRFRVGDILQIISKDDHNWWQAKLENSKNGTAGLIPS 59


>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 = 28.0 bits (62), Expect = 0.12
 Identities = 10/50 (20%), Positives = 25/50 (50%), Gaps = 2/50 (4%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
            + Y  + +++L  + G+ +E++ + +  WW        + G  PSN++
Sbjct: 4  VAFSYLPQNEDELELKVGDIIEVVGEVEEGWW--EGVLNGKTGMFPSNFI 51


>gnl|CDD|212869 cd11936, SH3_UBASH3B, Src homology 3 domain of
          Ubiquitin-associated and SH3 domain-containing protein
          B.  UBASH3B, also called Suppressor of T cell receptor
          Signaling (STS)-1 or T cell Ubiquitin LigAnd (TULA)-2
          is an active phosphatase that is expressed
          ubiquitously. The phosphatase activity of UBASH3B is
          essential for its roles in the suppression of TCR
          signaling and the regulation of EGFR. It also interacts
          with Syk and functions as a negative regulator of
          platelet glycoprotein VI signaling. TULA proteins
          contain an N-terminal UBA domain, a central SH3 domain,
          and a C-terminal histidine phosphatase domain. They
          bind c-Cbl through the SH3 domain and to ubiquitin via
          UBA. SH3 domains are protein interaction domains that
          bind to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 62

 Score = 28.1 bits (62), Expect = 0.13
 Identities = 15/56 (26%), Positives = 27/56 (48%), Gaps = 6/56 (10%)

Query: 5  LYDYDARTDEDLSFRKGEH-----LEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +Y Y  + D++L    G++     +E  + ++G W    S  T   G +P NY+ K
Sbjct: 7  IYPYTPQNDDELELVPGDYIFMSPMEQTSTSEG-WIYGTSLTTGCSGLLPENYITK 61


>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 = 27.3 bits (61), Expect = 0.16
 Identities = 14/51 (27%), Positives = 23/51 (45%), Gaps = 2/51 (3%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
            L D  A+ DE+L  R+G+ + I       W+  R +   + G  P  +V
Sbjct: 3  RVLQDLSAQLDEELDLREGDVVTITGILDKGWF--RGELNGRRGIFPEGFV 51


>gnl|CDD|212998 cd12065, SH3_GRAF2, Src Homology 3 domain of GTPase Regulator
          Associated with Focal adhesion kinase 2.  GRAF2, also
          called Rho GTPase activating protein 10 (ARHGAP10) or
          PS-GAP, is a GAP with activity towards Cdc42 and RhoA.
          It regulates caspase-activated p21-activated protein
          kinase-2 (PAK-2p34). GRAF2 interacts with PAK-2p34,
          leading to its stabilization and decrease of cell
          death. It is highly expressed in skeletal muscle, and
          is involved in alpha-catenin recruitment at cell-cell
          junctions. GRAF2 contains an N-terminal BAR domain,
          followed by a Pleckstrin homology (PH) domain, a Rho
          GAP domain, and a C-terminal SH3 domain. The SH3 domain
          of GRAF binds PKNbeta, a target of the small GTPase
          Rho. SH3 domains bind to proline-rich ligands with
          moderate affinity and selectivity, preferentially to
          PxxP motifs; they play a role in the regulation of
          enzymes by intramolecular interactions, changing the
          subcellular localization of signal pathway components
          and mediate multiprotein complex assemblies.
          Length = 54

 Score = 27.3 bits (60), Expect = 0.18
 Identities = 17/50 (34%), Positives = 25/50 (50%), Gaps = 1/50 (2%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          A+Y  +A    +LSF  G   E +  ++   WL  +   K+ G IP NYV
Sbjct: 4  AVYPCEAEHSSELSFEVGAIFEDVTLSREPGWLEGTLNGKR-GLIPENYV 52


>gnl|CDD|212914 cd11981, SH3_VAV3_1, First Src homology 3 domain of VAV3 protein.
           VAV3 is ubiquitously expressed and functions as a
          phosphorylation-dependent guanine nucleotide exchange
          factor (GEF) for RhoA, RhoG, and Rac1. It has been
          implicated to function in the hematopoietic, bone,
          cerebellar, and cardiovascular systems. VAV3 is
          essential in axon guidance in neurons that control
          blood pressure and respiration. It is overexpressed in
          prostate cancer cells and it plays a role in regulating
          androgen receptor transcriptional activity. VAV
          proteins contain several domains that enable their
          function: N-terminal calponin homology (CH), acidic,
          RhoGEF (also called Dbl-homologous or DH), Pleckstrin
          Homology (PH), C1 (zinc finger), SH2, and two SH3
          domains. The SH3 domain of VAV is involved in the
          localization of proteins to specific sites within the
          cell, by interacting with proline-rich sequences within
          target proteins. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 62

 Score = 27.5 bits (61), Expect = 0.18
 Identities = 12/39 (30%), Positives = 22/39 (56%), Gaps = 1/39 (2%)

Query: 16 LSFRKGEHLEILN-DTQGDWWLARSKATKQEGYIPSNYV 53
          L+ + G+ +E+L  D    +W  R+  T + G+ PS+ V
Sbjct: 22 LNAQIGDTIEVLYADPHSLFWQGRNLTTGELGFFPSDAV 60


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

 Score = 27.6 bits (61), Expect = 0.18
 Identities = 16/56 (28%), Positives = 26/56 (46%), Gaps = 9/56 (16%)

Query: 4  ALYDYDARTDE-------DLSFRKGEHLEILNDTQGDWWLAR--SKATKQEGYIPS 50
          AL+DY+   D         L F++ + LE+++     WW A+       + G IPS
Sbjct: 4  ALFDYNPYEDRAIPCQEAGLPFKRRDILEVVSQDDPTWWQAKRVGDTNLRAGLIPS 59


>gnl|CDD|212797 cd11863, SH3_CACNB, Src Homology 3 domain of Voltage-dependent
          L-type calcium channel subunit beta.  Voltage-dependent
          calcium channels (Ca(V)s) are multi-protein complexes
          that regulate the entry of calcium into cells. They
          impact muscle contraction, neuronal migration, hormone
          and neurotransmitter release, and the activation of
          calcium-dependent signaling pathways. They are composed
          of four subunits: alpha1, alpha2delta, beta, and gamma.
          The beta subunit is a soluble and intracellular protein
          that interacts with the transmembrane alpha1 subunit.
          It facilitates the trafficking and proper localization
          of the alpha1 subunit to the cellular plasma membrane.
          Vertebrates contain four different beta subunits from
          distinct genes (beta1-4); each exists as multiple
          splice variants. All are expressed in the brain while
          other tissues show more specific expression patterns.
          The beta subunits show similarity to MAGUK
          (membrane-associated guanylate kinase) proteins in that
          they contain SH3 and inactive guanylate kinase (GuK)
          domains; however, they do not appear to contain a PDZ
          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 = 27.2 bits (61), Expect = 0.25
 Identities = 17/53 (32%), Positives = 22/53 (41%), Gaps = 8/53 (15%)

Query: 6  YDYDARTDED-------LSFRKGEHLEILNDTQGDWWLAR-SKATKQEGYIPS 50
            YD   D+D       +SF   + L I      DWW+ R  K     G+IPS
Sbjct: 7  VGYDGSLDDDSPVPGYAVSFEAKDFLHIKEKYNNDWWIGRLVKEGCDIGFIPS 59


>gnl|CDD|212710 cd11776, SH3_PI3K_p85, Src Homology 3 domain of the p85
          regulatory subunit of Class IA Phosphatidylinositol
          3-kinases.  Class I PI3Ks convert PtdIns(4,5)P2 to the
          critical second messenger PtdIns(3,4,5)P3. They are
          heterodimers and exist in multiple isoforms consisting
          of one catalytic subunit (out of four isoforms) and one
          of several regulatory subunits. Class IA PI3Ks
          associate with the p85 regulatory subunit family, which
          contains SH3, RhoGAP, and SH2 domains. The p85 subunits
          recruit the PI3K p110 catalytic subunit to the
          membrane, where p110 phosphorylates inositol lipids.
          Vertebrates harbor two p85 isoforms, called alpha and
          beta. SH3 domains are protein interaction domains that
          bind to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 72

 Score = 26.7 bits (59), Expect = 0.38
 Identities = 18/65 (27%), Positives = 28/65 (43%), Gaps = 15/65 (23%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILN---------DTQG------DWWLARSKATKQEGYI 48
          ALYDY+   DED+  + G+ L + N         D +        W   +++ T + G  
Sbjct: 5  ALYDYEKERDEDIILKTGDVLVVENPELLALGVPDGKETVPKPEGWLEGKNERTGERGDF 64

Query: 49 PSNYV 53
          P  YV
Sbjct: 65 PGTYV 69


>gnl|CDD|212917 cd11984, SH3_Shank3, Src homology 3 domain of SH3 and multiple
          ankyrin repeat domains protein 3.  Shank3, also called
          ProSAP2 (Proline-rich synapse-associated protein 2), is
          widely expressed. It plays a role in the formation of
          dendritic spines and synapses. Haploinsufficiency of
          the Shank3 gene causes the 22q13
          deletion/Phelan-McDermid syndrome, and variants of
          Shank3 have been implicated in autism spectrum
          disorder, schizophrenia, and intellectual disability.
          Shank proteins carry scaffolding functions through
          multiple sites of protein-protein interaction in its
          domain architecture, including ankyrin (ANK) repeats, a
          long proline rich region, as well as SH3, PDZ, and SAM
          domains. The SH3 domain of Shank binds GRIP, a scaffold
          protein that binds AMPA receptors and Eph
          receptors/ligands. SH3 domains are protein interaction
          domains that bind to proline-rich ligands with moderate
          affinity and selectivity, preferentially to PxxP
          motifs. They play versatile and diverse roles in the
          cell including the regulation of enzymes, changing the
          subcellular localization of signaling pathway
          components, and mediating the formation of multiprotein
          complex assemblies.
          Length = 52

 Score = 26.1 bits (57), Expect = 0.47
 Identities = 12/52 (23%), Positives = 29/52 (55%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          F+A+  Y  + + ++   +GE +++L+  +G +W    K   + G+ P++ V
Sbjct: 3  FIAVKAYSPQGEGEIQLNRGERVKVLSIGEGGFWEGTVKG--RTGWFPADCV 52


>gnl|CDD|212912 cd11979, SH3_VAV1_1, First Src homology 3 domain of VAV1 protein.
           VAV1 is expressed predominantly in the hematopoietic
          system and it plays an important role in the
          development and activation of B and T cells. It is
          activated by tyrosine phosphorylation to function as a
          guanine nucleotide exchange factor (GEF) for Rho
          GTPases following cell surface receptor activation,
          triggering various effects such as cytoskeletal
          reorganization, transcription regulation, cell cycle
          progression, and calcium mobilization. It also serves
          as a scaffold protein and has been shown to interact
          with Ku70, Socs1, Janus kinase 2, SIAH2, S100B, Abl
          gene, ZAP-70, SLP76, and Syk, among others. VAV
          proteins contain several domains that enable their
          function: N-terminal calponin homology (CH), acidic,
          RhoGEF (also called Dbl-homologous or DH), Pleckstrin
          Homology (PH), C1 (zinc finger), SH2, and two SH3
          domains. The first SH3 domain of Vav1 has been shown to
          bind the adaptor protein Grb2. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 63

 Score = 26.5 bits (58), Expect = 0.49
 Identities = 11/39 (28%), Positives = 21/39 (53%), Gaps = 1/39 (2%)

Query: 16 LSFRKGEHLEILN-DTQGDWWLARSKATKQEGYIPSNYV 53
          L    G+ +E+   + + +WW  R+ +T + G+ P N V
Sbjct: 22 LRLNPGDIVELTKAEAEQNWWEGRNTSTNEIGWFPCNRV 60


>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 = 26.1 bits (57), Expect = 0.56
 Identities = 11/28 (39%), Positives = 17/28 (60%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQ 31
          ALY Y  ++ E+LSF +G  + +L   Q
Sbjct: 4  ALYSYTGQSPEELSFPEGALIRLLPRAQ 31


>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 = 26.2 bits (57), Expect = 0.56
 Identities = 11/54 (20%), Positives = 27/54 (50%), Gaps = 2/54 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAK 55
          +  + D+     + +SF+ G  +E++      WW  + +   +EG+ P+ ++ K
Sbjct: 2  YYTIADFQTTIPDGISFQAGLKVEVIEKNLSGWWYIQIE--DKEGWAPATFIDK 53


>gnl|CDD|212870 cd11937, SH3_UBASH3A, Src homology 3 domain of
          Ubiquitin-associated and SH3 domain-containing protein
          A.  UBASH3A is also called Cbl-Interacting Protein 4
          (CLIP4), T cell Ubiquitin LigAnd (TULA), or T cell
          receptor Signaling (STS)-2. It is only found in
          lymphoid cells and exhibits weak phosphatase activity.
          UBASH3A facilitates T cell-induced apoptosis through
          interaction with the apoptosis-inducing factor AIF. It
          is involved in regulating the level of phosphorylation
          of the zeta-associated protein (ZAP)-70 tyrosine
          kinase. TULA proteins contain an N-terminal UBA domain,
          a central SH3 domain, and a C-terminal histidine
          phosphatase domain. They bind c-Cbl through the SH3
          domain and to ubiquitin via UBA. SH3 domains are
          protein interaction domains that bind to proline-rich
          ligands with moderate affinity and selectivity,
          preferentially to PxxP motifs. They play versatile and
          diverse roles in 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 = 26.1 bits (57), Expect = 0.64
 Identities = 14/57 (24%), Positives = 27/57 (47%), Gaps = 6/57 (10%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGD-----WWLARSKATKQEGYIPSNYVAK 55
          AL+ Y  +  ++L    G+++  ++ TQ       W +  S  T   G++P NY  +
Sbjct: 5  ALFQYKPQNIDELMLSPGDYI-FVDPTQQSEASEGWVIGISHRTGCRGFLPENYTER 60


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

 Score = 25.4 bits (56), Expect = 0.93
 Identities = 13/52 (25%), Positives = 27/52 (51%), Gaps = 1/52 (1%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARS-KATKQEGYIPSNYV 53
          + LYD+ A   ++L  + G+ + I   +  +W++A+        G IP ++V
Sbjct: 3  IVLYDFKAERPDELDAKAGDAIIICAHSNYEWFVAKPIGRLGGPGLIPVSFV 54


>gnl|CDD|212974 cd12041, SH3_CACNB1, Src Homology 3 domain of Voltage-dependent
          L-type calcium channel subunit beta-1.  The beta1
          subunit of voltage-dependent calcium channels (Ca(V)s)
          is one of four beta subunits present in vertebrates. It
          is the only beta subunit, as the beta1a variant,
          expressed in skeletal muscle; the beta1b variant is
          also widely expressed in other tissues including the
          heart and brain. Knockout of the beta1 gene in mice
          results in embryonic lethality, demonstrating its
          importance in development. Ca(V)s are multi-protein
          complexes that regulate the entry of calcium into
          cells. They impact muscle contraction, neuronal
          migration, hormone and neurotransmitter release, and
          the activation of calcium-dependent signaling pathways.
          They are composed of four subunits: alpha1,
          alpha2delta, beta, and gamma. The beta subunit is a
          soluble and intracellular protein that interacts with
          the transmembrane alpha1 subunit. It facilitates the
          trafficking and proper localization of the alpha1
          subunit to the cellular plasma membrane. Vertebrates
          contain four different beta subunits from distinct
          genes (beta1-4); each exists as multiple splice
          variants. All are expressed in the brain while other
          tissues show more specific expression patterns. The
          beta subunits show similarity to MAGUK
          (membrane-associated guanylate kinase) proteins in that
          they contain SH3 and inactive guanylate kinase (GuK)
          domains; however, they do not appear to contain a PDZ
          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 = 68

 Score = 25.7 bits (56), Expect = 0.97
 Identities = 13/36 (36%), Positives = 18/36 (50%), Gaps = 1/36 (2%)

Query: 16 LSFRKGEHLEILNDTQGDWWLARS-KATKQEGYIPS 50
          +SF   + L I      DWW+ R  K   + G+IPS
Sbjct: 28 ISFEPKDFLHIKEKYNNDWWIGRLVKEGCEVGFIPS 63


>gnl|CDD|212920 cd11987, SH3_Intersectin1_1, First Src homology 3 domain (or
          SH3A) of Intersectin-1.  Intersectin-1 (ITSN1) is an
          adaptor protein that functions in exo- and endocytosis,
          actin cytoskeletal reorganization, and signal
          transduction. It plays a role in clathrin-coated pit
          (CCP) formation. It binds to many proteins through its
          multidomain structure and facilitate the assembly of
          multimeric complexes. ITSN1 localizes in membranous
          organelles, CCPs, the Golgi complex, and may be
          involved in the cell membrane trafficking system. It
          exists in alternatively spliced short and long
          isoforms. The short isoform contains two Eps15 homology
          domains (EH1 and EH2), a coiled-coil region and five
          SH3 domains (SH3A-E), while the long isoform, in
          addition, contains RhoGEF (also called Dbl-homologous
          or DH), Pleckstrin homology (PH) and C2 domains. The
          first SH3 domain (or SH3A) of ITSN1 has been shown to
          bind many proteins including Sos1, dynamin1/2, CIN85,
          c-Cbl, PI3K-C2, SHIP2, N-WASP, and CdGAP, among others.
          SH3 domains are protein interaction domains that bind
          to proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 55

 Score = 25.3 bits (55), Expect = 0.97
 Identities = 14/55 (25%), Positives = 31/55 (56%), Gaps = 2/55 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGD-WWLARSKATKQEGYIPSNYVAK 55
          + ALY ++AR+ ++++ + G+ + +     G+  WL   +   + G+ P+NY  K
Sbjct: 2  YRALYPFEARSHDEITIQPGDIVMVDESQTGEPGWLG-GELKGKTGWFPANYAEK 55


>gnl|CDD|180419 PRK06134, PRK06134, putative FAD-binding dehydrogenase; Reviewed.
          Length = 581

 Score = 26.6 bits (59), Expect = 1.1
 Identities = 12/31 (38%), Positives = 15/31 (48%), Gaps = 2/31 (6%)

Query: 3   VALYDYDARTDEDLSFRKGEHLEILNDTQGD 33
           VA Y+  AR  +D  F +G      N  QGD
Sbjct: 450 VARYNRHARNGQDPDFGRGSTP--YNRKQGD 478


>gnl|CDD|212948 cd12015, SH3_Tks_1, First Src homology 3 domain of Tyrosine
          kinase substrate (Tks) proteins.  Tks proteins are Src
          substrates and scaffolding proteins that play important
          roles in the formation of podosomes and invadopodia,
          the dynamic actin-rich structures that are related to
          cell migration and cancer cell invasion. Vertebrates
          contain two Tks proteins, Tks4 (Tyr kinase substrate
          with four SH3 domains) and Tks5 (Tyr kinase substrate
          with five SH3 domains), which display partially
          overlapping but non-redundant functions. Both associate
          with the ADAMs family of transmembrane
          metalloproteases, which function as sheddases and
          mediators of cell and matrix interactions. Tks5
          interacts with N-WASP and Nck, while Tks4 is essential
          for the localization of MT1-MMP (membrane-type 1 matrix
          metalloproteinase) to invadopodia. Tks proteins contain
          an N-terminal Phox homology (PX) domain and four or
          five SH3 domains. This model characterizes the first
          SH3 domain of Tks proteins. SH3 domains are protein
          interaction domains that bind to proline-rich ligands
          with moderate affinity and selectivity, preferentially
          to PxxP motifs. They play versatile and diverse roles
          in the cell including the regulation of enzymes,
          changing the subcellular localization of signaling
          pathway components, and mediating the formation of
          multiprotein complex assemblies.
          Length = 53

 Score = 25.1 bits (55), Expect = 1.3
 Identities = 11/51 (21%), Positives = 28/51 (54%), Gaps = 2/51 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNY 52
          +V + DY  +   ++S R G+ ++++   +  WW    +   ++G++P+ Y
Sbjct: 2  YVVVADYKKQQPNEISLRAGDVVDVIEKNENGWWFVSLE--DEQGWVPATY 50


>gnl|CDD|212916 cd11983, SH3_Shank2, Src homology 3 domain of SH3 and multiple
          ankyrin repeat domains protein 2.  Shank2, also called
          ProSAP1 (Proline-rich synapse-associated protein 1) or
          CortBP1 (Cortactin-binding protein 1), is found in
          neurons, glia, endocrine cells, liver, and kidney. It
          plays a role in regulating dendritic spine volume and
          branching and postsynaptic clustering. Mutations in the
          Shank2 gene are associated with autism spectrum
          disorder and mental retardation. Shank proteins carry
          scaffolding functions through multiple sites of
          protein-protein interaction in its domain architecture,
          including ankyrin (ANK) repeats, a long proline rich
          region, as well as SH3, PDZ, and SAM domains. The SH3
          domain of Shank binds GRIP, a scaffold protein that
          binds AMPA receptors and Eph receptors/ligands. SH3
          domains are protein interaction domains that bind to
          proline-rich ligands with moderate affinity and
          selectivity, preferentially to PxxP motifs. They play
          versatile and diverse roles in the cell including the
          regulation of enzymes, changing the subcellular
          localization of signaling pathway components, and
          mediating the formation of multiprotein complex
          assemblies.
          Length = 52

 Score = 24.9 bits (54), Expect = 1.6
 Identities = 12/52 (23%), Positives = 26/52 (50%), Gaps = 2/52 (3%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILNDTQGDWWLARSKATKQEGYIPSNYV 53
          FV +  Y  + + ++   KG+ +++L+  +G +W     A    G+ P+  V
Sbjct: 3  FVVVKSYQPQVEGEIPLHKGDRVKVLSIGEGGFW--EGSARGHVGWFPAECV 52


>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 = 25.0 bits (54), Expect = 1.8
 Identities = 16/54 (29%), Positives = 24/54 (44%), Gaps = 4/54 (7%)

Query: 5  LYDYDARTDEDLSFRKGEHLEILN--DTQGDWWLARSKATKQEGYIPSNYVAKL 56
          LYDYDA    +LS    E + + +      DW +       Q+G +P  Y+  L
Sbjct: 9  LYDYDAANSTELSLLADEVITVYSVPGMDSDWLMGERG--NQKGKVPITYLELL 60


>gnl|CDD|223545 COG0469, PykF, Pyruvate kinase [Carbohydrate transport and
          metabolism].
          Length = 477

 Score = 25.6 bits (57), Expect = 1.9
 Identities = 5/19 (26%), Positives = 10/19 (52%)

Query: 14 EDLSFRKGEHLEILNDTQG 32
           + + + G  + IL D +G
Sbjct: 54 REAAEKLGRPVAILLDLKG 72


>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 = 24.7 bits (54), Expect = 2.0
 Identities = 13/34 (38%), Positives = 18/34 (52%), Gaps = 1/34 (2%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDWWL 36
          VALY + A    +L F  G+ + I+  T  D WL
Sbjct: 3  VALYRFQALEPNELDFEVGDRIRIIA-TLEDGWL 35


>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 = 24.5 bits (53), Expect = 2.0
 Identities = 16/55 (29%), Positives = 29/55 (52%), Gaps = 6/55 (10%)

Query: 2  FVALYDYDARTDEDLSFRKGEHLEILN---DTQGDWWLARSKATKQEGYIPSNYV 53
          +  L+D      ++LSF++G+ + IL+   +  G WW+   K T   G +P  Y+
Sbjct: 2  YQGLWDCTGDQPDELSFKRGDTIYILSKEYNRFG-WWVGEMKGTI--GLVPKAYI 53


>gnl|CDD|234534 TIGR04286, MSEP-CTERM, MSEP-CTERM protein.  Members of this protein
           family average over 900 residues in length and appear to
           have multiple membrane-spanning helices in the
           N-terminal half. The extreme C-terminal region consists
           of a motif with consensus sequence MSEP, then a
           transmembrane alpha helix, then a short region with
           several basic residues. This region, hereby dubbed
           MSEP-CTERM, resembles other putative sorting signals
           associated with the archaeosortase/exosortase protein
           family (see TIGR04178). Genes for all members of this
           family are found next to a gene for exosortase K.
          Length = 920

 Score = 25.4 bits (56), Expect = 2.3
 Identities = 8/44 (18%), Positives = 17/44 (38%)

Query: 21  GEHLEILNDTQGDWWLARSKATKQEGYIPSNYVAKLKSIEAEPY 64
           G  +++  D++         +     Y+ + Y   L  +E  PY
Sbjct: 590 GTPIDLKGDSEPQKQHTSEISLNGVAYLSAAYKKTLPKVELPPY 633


>gnl|CDD|212976 cd12043, SH3_CACNB4, Src Homology 3 domain of Voltage-dependent
          L-type calcium channel subunit beta4.  The beta4
          subunit of voltage-dependent calcium channels (Ca(V)s)
          is one of four beta subunits present in vertebrates. It
          is the only beta subunit expressed in the cochlea and
          is highly expressed in the brain, predominantly in the
          cerebellum. Ca(V)s are multi-protein complexes that
          regulate the entry of calcium into cells. They impact
          muscle contraction, neuronal migration, hormone and
          neurotransmitter release, and the activation of
          calcium-dependent signaling pathways. They are composed
          of four subunits: alpha1, alpha2delta, beta, and gamma.
          The beta subunit is a soluble and intracellular protein
          that interacts with the transmembrane alpha1 subunit.
          It facilitates the trafficking and proper localization
          of the alpha1 subunit to the cellular plasma membrane.
          Vertebrates contain four different beta subunits from
          distinct genes (beta1-4); each exists as multiple
          splice variants. All are expressed in the brain while
          other tissues show more specific expression patterns.
          The beta subunits show similarity to MAGUK
          (membrane-associated guanylate kinase) proteins in that
          they contain SH3 and inactive guanylate kinase (GuK)
          domains; however, they do not appear to contain a PDZ
          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 = 68

 Score = 24.6 bits (53), Expect = 2.4
 Identities = 13/36 (36%), Positives = 18/36 (50%), Gaps = 1/36 (2%)

Query: 16 LSFRKGEHLEILNDTQGDWWLAR-SKATKQEGYIPS 50
          +SF   + L I      DWW+ R  K   + G+IPS
Sbjct: 28 ISFDAKDFLHIKEKYNNDWWIGRLVKEGCEIGFIPS 63


>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 = 24.7 bits (54), Expect = 2.5
 Identities = 18/62 (29%), Positives = 27/62 (43%), Gaps = 4/62 (6%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQGDW---WL-ARSKATKQEGYIPSNYVAKLKS 58
           AL DY       L+F+KG+ + + +   G+    W  +        GY P N V +LK 
Sbjct: 15 RALEDYHGPDCRFLNFKKGDTIYVYSKLAGERQDLWAGSVGGDAGLFGYFPKNLVQELKV 74

Query: 59 IE 60
           E
Sbjct: 75 YE 76


>gnl|CDD|212973 cd12040, SH3_CACNB2, Src Homology 3 domain of Voltage-dependent
          L-type calcium channel subunit beta2.  The beta2
          subunit of voltage-dependent calcium channels (Ca(V)s)
          is one of four beta subunits present in vertebrates. It
          is expressed in the heart and is present in specific
          neuronal cells including cerebellar Purkinje cells,
          hippocampal pyramidal neurons, and photoreceptors.
          Knockout of the beta2 gene in mice results in embryonic
          lethality, demonstrating its importance in development.
          Ca(V)s are multi-protein complexes that regulate the
          entry of calcium into cells. They impact muscle
          contraction, neuronal migration, hormone and
          neurotransmitter release, and the activation of
          calcium-dependent signaling pathways. They are composed
          of four subunits: alpha1, alpha2delta, beta, and gamma.
          The beta subunit is a soluble and intracellular protein
          that interacts with the transmembrane alpha1 subunit.
          It facilitates the trafficking and proper localization
          of the alpha1 subunit to the cellular plasma membrane.
          Vertebrates contain four different beta subunits from
          distinct genes (beta1-4); each exists as multiple
          splice variants. All are expressed in the brain while
          other tissues show more specific expression patterns.
          The beta subunits show similarity to MAGUK
          (membrane-associated guanylate kinase) proteins in that
          they contain SH3 and inactive guanylate kinase (GuK)
          domains; however, they do not appear to contain a PDZ
          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 = 69

 Score = 24.6 bits (53), Expect = 2.7
 Identities = 15/51 (29%), Positives = 23/51 (45%), Gaps = 8/51 (15%)

Query: 8  YDARTDED-------LSFRKGEHLEILNDTQGDWWLAR-SKATKQEGYIPS 50
          Y A  ++D       +SF   + L +      DWW+ R  K   + G+IPS
Sbjct: 14 YSAAHEDDVPVPGMAISFEAKDFLHVKEKFNNDWWIGRLVKEGCEIGFIPS 64


>gnl|CDD|218501 pfam05212, DUF707, Protein of unknown function (DUF707).  This
           family consists of several uncharacterized proteins from
           Arabidopsis thaliana.
          Length = 294

 Score = 25.1 bits (55), Expect = 3.0
 Identities = 12/39 (30%), Positives = 18/39 (46%), Gaps = 5/39 (12%)

Query: 3   VALYDYDARTDEDLSF---RKGEHLEILNDTQGDWWLAR 38
           + L+ YD RT E       +K  H+     T+  WW A+
Sbjct: 70  IVLFHYDGRTTEWDELEWSKKAIHVSAKKQTK--WWFAK 106


>gnl|CDD|212842 cd11909, SH3_PI3K_p85beta, Src Homology 3 domain of the p85beta
          regulatory subunit of Class IA Phosphatidylinositol
          3-kinases.  Class I PI3Ks convert PtdIns(4,5)P2 to the
          critical second messenger PtdIns(3,4,5)P3. They are
          heterodimers and exist in multiple isoforms consisting
          of one catalytic subunit (out of four isoforms) and one
          of several regulatory subunits. Class IA PI3Ks
          associate with the p85 regulatory subunit family, which
          contains SH3, RhoGAP, and SH2 domains. The p85 subunits
          recruit the PI3K p110 catalytic subunit to the
          membrane, where p110 phosphorylates inositol lipids.
          Vertebrates harbor two p85 isoforms, called alpha and
          beta. In addition to regulating the p110 subunit,
          p85beta binds CD28 and may be involved in the
          activation and differentiation of antigen-stimulated 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 = 74

 Score = 24.4 bits (53), Expect = 3.1
 Identities = 19/65 (29%), Positives = 26/65 (40%), Gaps = 15/65 (23%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEI-------LNDTQGD--------WWLARSKATKQEGYI 48
          ALY Y    +ED+    G+ L +       L   +G         W L  ++ TKQ G  
Sbjct: 5  ALYPYRKEREEDIDLLPGDVLTVSRAALQALGVKEGGEQCPQSIGWILGLNERTKQRGDF 64

Query: 49 PSNYV 53
          P  YV
Sbjct: 65 PGTYV 69


>gnl|CDD|215164 PLN02290, PLN02290, cytokinin trans-hydroxylase.
          Length = 516

 Score = 24.8 bits (54), Expect = 3.8
 Identities = 16/64 (25%), Positives = 28/64 (43%), Gaps = 14/64 (21%)

Query: 7   DYDARTDEDLSFRKGEHL-EILNDTQG-------DWWLARSKATKQEGYIPSNYVAKLKS 58
           D  +RT+ D S+ KG+ +  +L   Q              S+      + PS Y  ++KS
Sbjct: 209 DIISRTEFDSSYEKGKQIFHLLTVLQRLCAQATRHLCFPGSR------FFPSKYNREIKS 262

Query: 59  IEAE 62
           ++ E
Sbjct: 263 LKGE 266


>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 = 23.6 bits (51), Expect = 4.4
 Identities = 9/31 (29%), Positives = 19/31 (61%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDW 34
          AL+D+   +  +L+F+ G+ + +L+    DW
Sbjct: 4  ALFDFTGNSKLELNFKAGDVIFLLSRVNKDW 34


>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 = 23.8 bits (52), Expect = 4.7
 Identities = 15/55 (27%), Positives = 20/55 (36%), Gaps = 5/55 (9%)

Query: 3  VALYDYDARTDEDLSFRKGEHLEILNDTQG---DWWLARSKATKQEGYIPSNYVA 54
          VA+  Y  R    LSF KG+ +++L         W           G  P  YV 
Sbjct: 3  VAVRAYITRDQTLLSFHKGDVIKLLPKEGPLDPGWLFGTLDGRS--GAFPKEYVQ 55


>gnl|CDD|212961 cd12028, SH3_ZO-3, Src homology 3 domain of the Tight junction
          protein, Zonula occludens protein 3.  ZO-3 is a
          scaffolding protein that associates with other ZO
          proteins and other proteins of the tight junction,
          zonula adherens, and gap junctions. ZO proteins play
          roles in regulating cytoskeletal dynamics at these cell
          junctions. ZO-3 is critical for epidermal barrier
          function. It regulates cyclin D1-dependent cell
          proliferation. It is considered 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. The C-terminal region of ZO-3 is the
          smallest of the three ZO proteins. The SH3 domain of
          the related protein 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 = 65

 Score = 23.7 bits (51), Expect = 4.9
 Identities = 17/53 (32%), Positives = 25/53 (47%), Gaps = 9/53 (16%)

Query: 6  YDYDARTDEDLSFRKGEHLEILNDT----QGDWWLA----RSKATKQEGYIPS 50
          +DY+      LSF +GE   +L DT    +   WLA    R     ++G IP+
Sbjct: 9  FDYEPDPPSGLSFTRGEVFHVL-DTMHRGKLGSWLAVRMGRDLREMEKGIIPN 60


>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 = 23.4 bits (51), Expect = 5.7
 Identities = 14/51 (27%), Positives = 25/51 (49%), Gaps = 1/51 (1%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWL-ARSKATKQEGYIPSNYV 53
          ALY + A  +  LSF +G+ + +L     D W    ++ + + G+ P  Y 
Sbjct: 5  ALYPHAAGGETQLSFEEGDVITLLGPEPRDGWHYGENERSGRRGWFPIAYT 55


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

 Score = 23.4 bits (50), Expect = 5.8
 Identities = 10/33 (30%), Positives = 20/33 (60%)

Query: 4  ALYDYDARTDEDLSFRKGEHLEILNDTQGDWWL 36
          ALY+  A   ++L+F +GE + +  +   +WW+
Sbjct: 4  ALYNCVADNPDELTFSEGEIIIVDGEEDKEWWI 36


>gnl|CDD|128955 smart00715, LA, Domain in the RNA-binding Lupus La protein;
          unknown function. 
          Length = 80

 Score = 23.7 bits (52), Expect = 5.8
 Identities = 8/24 (33%), Positives = 15/24 (62%)

Query: 38 RSKATKQEGYIPSNYVAKLKSIEA 61
          R K  K +GY+P + +A  K +++
Sbjct: 27 RKKMDKNDGYVPISTIASFKRVKS 50


>gnl|CDD|203243 pfam05383, La, La domain.  This presumed domain is found at the
          N-terminus of La RNA-binding proteins as well as other
          proteins. The function of this region is uncertain.
          Length = 59

 Score = 22.9 bits (50), Expect = 8.4
 Identities = 8/24 (33%), Positives = 13/24 (54%)

Query: 38 RSKATKQEGYIPSNYVAKLKSIEA 61
          R +  K  GY+P + +A  K I+ 
Sbjct: 21 RKQMDKDPGYVPISTIASFKRIKK 44


  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
   0.316    0.134    0.404 

Gapped
Lambda     K      H
   0.267   0.0769    0.140 


Matrix: BLOSUM62
Gap Penalties: Existence: 11, Extension: 1
Number of Sequences: 44354
Number of Hits to DB: 3,522,707
Number of extensions: 246977
Number of successful extensions: 585
Number of sequences better than 10.0: 1
Number of HSP's gapped: 507
Number of HSP's successfully gapped: 290
Length of query: 70
Length of database: 10,937,602
Length adjustment: 40
Effective length of query: 30
Effective length of database: 9,163,442
Effective search space: 274903260
Effective search space used: 274903260
Neighboring words threshold: 11
Window for multiple hits: 40
X1: 16 ( 7.3 bits)
X2: 38 (14.6 bits)
X3: 64 (24.7 bits)
S1: 41 (21.6 bits)
S2: 53 (24.1 bits)