Cloned out of library/PAK-interactive exchange factor pleckstrin homology (PH) domain; There are two forms of Pix proteins: alpha Pix (also called Rho guanine nucleotide exchange factor (GEF) 6/90Cool-2) and beta Pix (GEF7/p85Cool-1). betaPix contains an N-terminal SH3 domain, a RhoGEF/DH domain, a PH domain, a GIT1 binding domain (GBD), and a C-terminal coiled-coil (CC) domain. alphaPix differs in that it contains a calponin homology (CH) domain, which interacts with beta-parvin, N-terminal to the SH3 domain. alphaPix is an exchange factor for Rac1 and Cdc42 and mediates Pak activation on cell adhesion to fibronectin. Mutations in alphaPix can cause X-linked mental retardation. alphaPix also interacts with Huntington's disease protein (htt), and enhances the aggregation of mutant htt (muthtt) by facilitating SDS-soluble muthtt-muthtt interactions. The DH-PH domain of a Pix was required for its binding to htt. In the majority of Rho GEF proteins, the DH-PH domain is responsible for the exchange activity. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 377 VLYMSQVLIQCAGSEEKNERYLLLFPNILLMLSASSRMSGFIYQGKLPTTGMTITKLEDSENHRNAFEISGSMIERILVS 456
Cdd:cd01225    1 VIHMSQVAVQNTGCQEKKERYFLLFPHVLLMLSASPRMSGFIYEGKLPLTGISVNRLEDTEGIKNAFEISGPLIERIVVI 80

                         90       100
                 ....*....|....*....|
gi 528972046 457 CSNQQDLHEWVDRLQKQTKA 476
Cdd:cd01225   81 CNSQQDQQEWLEHLQQQTKA 100

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 169 YNVVLQNILETENEYSKELQTVLSTYLRPLQTSEK-LSSANTSHLMGNLEEICSFQQMLVQSLEECTKM-PEAQQRVGGC 246
Cdd:cd00160    1 RQEVIKELLQTERNYVRDLKLLVEVFLKPLDKELLpLSPEEVELLFGNIEEIYEFHRIFLKSLEERVEEwDKSGPRIGDV 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 247 FLSLMPQMKTlYLTYCANHPSAVSVLTEHSEELGEFMEL--KGASSPGILVLTTGLSKPFMRLDKYPALLKELERHMEDY 324
Cdd:cd00160   81 FLKLAPFFKI-YSEYCSNHPDALELLKKLKKFNKFFQEFleKAESECGRLKLESLLLKPVQRLTKYPLLLKELLKHTPDG 159

                        170       180
                 ....*....|....*....|..
gi 528972046 325 HPDRQDIQKSMTAFKNLSAQCQ 346
Cdd:cd00160  160 HEDREDLKKALEAIKEVASQVN 181

calponin homology (CH) domain superfamily; CH domains are actin filament (F-actin) binding motifs, which may be present as a single copy or in tandem repeats (which increase binding affinity). They either function as autonomous actin binding motifs or serve a regulatory function. CH domains are found in cytoskeletal and signal transduction proteins, including actin-binding proteins like spectrin, alpha-actinin, dystrophin, utrophin, and fimbrin, as well as proteins essential for regulation of cell shape (cortexillins), and signaling proteins (Vav).

                         10        20        30
                 ....*....|....*....|....*....|...
gi 528972046   1 MKTFDANDLYQGQNFNKVLSSLVTLNKVTADIG 33
Cdd:cd21266   80 LETFDANDLYQGQNFNKVLSSLVALNKVTADIG 112

Cloned out of library/PAK-interactive exchange factor pleckstrin homology (PH) domain; There are two forms of Pix proteins: alpha Pix (also called Rho guanine nucleotide exchange factor (GEF) 6/90Cool-2) and beta Pix (GEF7/p85Cool-1). betaPix contains an N-terminal SH3 domain, a RhoGEF/DH domain, a PH domain, a GIT1 binding domain (GBD), and a C-terminal coiled-coil (CC) domain. alphaPix differs in that it contains a calponin homology (CH) domain, which interacts with beta-parvin, N-terminal to the SH3 domain. alphaPix is an exchange factor for Rac1 and Cdc42 and mediates Pak activation on cell adhesion to fibronectin. Mutations in alphaPix can cause X-linked mental retardation. alphaPix also interacts with Huntington's disease protein (htt), and enhances the aggregation of mutant htt (muthtt) by facilitating SDS-soluble muthtt-muthtt interactions. The DH-PH domain of a Pix was required for its binding to htt. In the majority of Rho GEF proteins, the DH-PH domain is responsible for the exchange activity. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 377 VLYMSQVLIQCAGSEEKNERYLLLFPNILLMLSASSRMSGFIYQGKLPTTGMTITKLEDSENHRNAFEISGSMIERILVS 456
Cdd:cd01225    1 VIHMSQVAVQNTGCQEKKERYFLLFPHVLLMLSASPRMSGFIYEGKLPLTGISVNRLEDTEGIKNAFEISGPLIERIVVI 80

                         90       100
                 ....*....|....*....|
gi 528972046 457 CSNQQDLHEWVDRLQKQTKA 476
Cdd:cd01225   81 CNSQQDQQEWLEHLQQQTKA 100

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 169 YNVVLQNILETENEYSKELQTVLSTYLRPLQTSEK-LSSANTSHLMGNLEEICSFQQMLVQSLEECTKM-PEAQQRVGGC 246
Cdd:cd00160    1 RQEVIKELLQTERNYVRDLKLLVEVFLKPLDKELLpLSPEEVELLFGNIEEIYEFHRIFLKSLEERVEEwDKSGPRIGDV 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 247 FLSLMPQMKTlYLTYCANHPSAVSVLTEHSEELGEFMEL--KGASSPGILVLTTGLSKPFMRLDKYPALLKELERHMEDY 324
Cdd:cd00160   81 FLKLAPFFKI-YSEYCSNHPDALELLKKLKKFNKFFQEFleKAESECGRLKLESLLLKPVQRLTKYPLLLKELLKHTPDG 159

                        170       180
                 ....*....|....*....|..
gi 528972046 325 HPDRQDIQKSMTAFKNLSAQCQ 346
Cdd:cd00160  160 HEDREDLKKALEAIKEVASQVN 181

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVREV 138
Cdd:cd12061    1 VVRAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVREI 54

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.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 528972046    86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGT-HNGRTGWFPSNYVR 136
Cdd:smart00326   5 VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRlGRGKEGLFPSNYVE 56

calponin homology (CH) domain found in beta-Pak Interactive eXchange factor; Beta-Pak Interactive eXchange factor (beta-PIX), also called PAK-interacting exchange factor beta, Rho guanine nucleotide exchange factor 7 (ARHGEF7), p85, 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 Rac1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. Beta-PIX contains a single copy of the CH domain at its N-terminus. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30
                 ....*....|....*....|....*....|...
gi 528972046   1 MKTFDANDLYQGQNFNKVLSSLVTLNKVTADIG 33
Cdd:cd21266   80 LETFDANDLYQGQNFNKVLSSLVALNKVTADIG 112

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046   389 GSEEKNERYLLLFPNILLMLSASSRMSGFIYQGKLPTTGMTITKLEDSEN--HRNAFEISGSMIERILVSCSNQQDLHEW 466
Cdd:smart00233  14 GKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTVREAPDPDSskKPHCFEIKTSDRKTLLLQAESEEEREKW 93

                   ....*....
gi 528972046   467 VDRLQKQTK 475
Cdd:smart00233  94 VEALRKAIA 102

large tegument protein UL36; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046  474 TKAASAGNPSSKPHSVPSHTLPSHSITPSSKHADSKPAPLTPAYHTLPHPSHHGT-PHTTINWGPLEPPKTPKPWSLScl 552
Cdd:PHA03247 2763 TAGPPAPAPPAAPAAGPPRRLTRPAVASLSESRESLPSPWDPADPPAAVLAPAAAlPPAASPAGPLPPPTSAQPTAPP-- 2840

                          90       100       110       120       130       140
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046  553 RPAPPLRPSAALCYK----EDLSKSPKT----MKKLLPKRKPERK-------PSDEEFAL 597
Cdd:PHA03247 2841 PPPGPPPPSLPLGGSvapgGDVRRRPPSrspaAKPAAPARPPVRRlarpavsRSTESFAL 2900

Cloned out of library/PAK-interactive exchange factor pleckstrin homology (PH) domain; There are two forms of Pix proteins: alpha Pix (also called Rho guanine nucleotide exchange factor (GEF) 6/90Cool-2) and beta Pix (GEF7/p85Cool-1). betaPix contains an N-terminal SH3 domain, a RhoGEF/DH domain, a PH domain, a GIT1 binding domain (GBD), and a C-terminal coiled-coil (CC) domain. alphaPix differs in that it contains a calponin homology (CH) domain, which interacts with beta-parvin, N-terminal to the SH3 domain. alphaPix is an exchange factor for Rac1 and Cdc42 and mediates Pak activation on cell adhesion to fibronectin. Mutations in alphaPix can cause X-linked mental retardation. alphaPix also interacts with Huntington's disease protein (htt), and enhances the aggregation of mutant htt (muthtt) by facilitating SDS-soluble muthtt-muthtt interactions. The DH-PH domain of a Pix was required for its binding to htt. In the majority of Rho GEF proteins, the DH-PH domain is responsible for the exchange activity. PH domains have diverse functions, but in general are involved in targeting proteins to the appropriate cellular location or in the interaction with a binding partner. They share little sequence conservation, but all have a common fold, which is electrostatically polarized. Less than 10% of PH domains bind phosphoinositide phosphates (PIPs) with high affinity and specificity. PH domains are distinguished from other PIP-binding domains by their specific high-affinity binding to PIPs with two vicinal phosphate groups: PtdIns(3,4)P2, PtdIns(4,5)P2 or PtdIns(3,4,5)P3 which results in targeting some PH domain proteins to the plasma membrane. A few display strong specificity in lipid binding. Any specificity is usually determined by loop regions or insertions in the N-terminus of the domain, which are not conserved across all PH domains. PH domains are found in cellular signaling proteins such as serine/threonine kinase, tyrosine kinases, regulators of G-proteins, endocytotic GTPases, adaptors, as well as cytoskeletal associated molecules and in lipid associated enzymes.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 377 VLYMSQVLIQCAGSEEKNERYLLLFPNILLMLSASSRMSGFIYQGKLPTTGMTITKLEDSENHRNAFEISGSMIERILVS 456
Cdd:cd01225    1 VIHMSQVAVQNTGCQEKKERYFLLFPHVLLMLSASPRMSGFIYEGKLPLTGISVNRLEDTEGIKNAFEISGPLIERIVVI 80

                         90       100
                 ....*....|....*....|
gi 528972046 457 CSNQQDLHEWVDRLQKQTKA 476
Cdd:cd01225   81 CNSQQDQQEWLEHLQQQTKA 100

Guanine nucleotide exchange factor for Rho/Rac/Cdc42-like GTPases; Also called Dbl-homologous (DH) domain. It appears that PH domains invariably occur C-terminal to RhoGEF/DH domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 169 YNVVLQNILETENEYSKELQTVLSTYLRPLQTSEK-LSSANTSHLMGNLEEICSFQQMLVQSLEECTKM-PEAQQRVGGC 246
Cdd:cd00160    1 RQEVIKELLQTERNYVRDLKLLVEVFLKPLDKELLpLSPEEVELLFGNIEEIYEFHRIFLKSLEERVEEwDKSGPRIGDV 80

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 528972046 247 FLSLMPQMKTlYLTYCANHPSAVSVLTEHSEELGEFMEL--KGASSPGILVLTTGLSKPFMRLDKYPALLKELERHMEDY 324
Cdd:cd00160   81 FLKLAPFFKI-YSEYCSNHPDALELLKKLKKFNKFFQEFleKAESECGRLKLESLLLKPVQRLTKYPLLLKELLKHTPDG 159

                        170       180
                 ....*....|....*....|..
gi 528972046 325 HPDRQDIQKSMTAFKNLSAQCQ 346
Cdd:cd00160  160 HEDREDLKKALEAIKEVASQVN 181

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVREV 138
Cdd:cd12061    1 VVRAKFNFQQTNEDELSFSKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVREI 54

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11877    1 LVRAKFNFEGTNEDELSFDKGDIITVTQVVEGGWWEGTLNGKTGWFPSNYVKE 53

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.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 528972046    86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGT-HNGRTGWFPSNYVR 136
Cdd:smart00326   5 VRALYDYTAQDPDELSFKKGDIITVLEKSDDGWWKGRlGRGKEGLFPSNYVE 56

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11766    1 PAVVKFNYEAQREDELSLRKGDRVLVLEKSSDGWWRGECNGQVGWFPSNYVTE 53

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|..
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11840    2 VIALFPYTAQNEDELSFQKGDIINVLSKDDPDWWRGELNGQTGLFPSNYVEP 53

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  87 RAKFNFQQTNEDELSFAKGDVIHVTR--VEEGGWWEGTHNGRTGWFPSNYV 135
Cdd:cd12142    3 RVLFDYNPVAPDELALKKGDVIEVISkeTEDEGWWEGELNGRRGFFPDNFV 53

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYV 135
Cdd:cd11826    2 VVALYDYTADKDDELSFQEGDIIYVTKKNDDGWYEGVLNGVTGLFPGNYV 51

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  87 RAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11874    3 KVLFSYTPQNEDELELKVGDTIEVLGEVEEGWWEGKLNGKVGVFPSNFVKE 53

calponin homology (CH) domain found in beta-Pak Interactive eXchange factor; Beta-Pak Interactive eXchange factor (beta-PIX), also called PAK-interacting exchange factor beta, Rho guanine nucleotide exchange factor 7 (ARHGEF7), p85, 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 Rac1, and plays important roles in regulating neuroendocrine exocytosis, focal adhesion maturation, cell migration, synaptic vesicle localization, and insulin secretion. Beta-PIX contains a single copy of the CH domain at its N-terminus. CH domains are actin filament (F-actin) binding motifs.

                         10        20        30
                 ....*....|....*....|....*....|...
gi 528972046   1 MKTFDANDLYQGQNFNKVLSSLVTLNKVTADIG 33
Cdd:cd21266   80 LETFDANDLYQGQNFNKVLSSLVALNKVTADIG 112

SH3 domain; SH3 (Src homology 3) domains are often indicative of a protein involved in signal transduction related to cytoskeletal organization. First described in the Src cytoplasmic tyrosine kinase. The structure is a partly opened beta barrel.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*..
gi 528972046   87 RAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGT-HNGRTGWFPS 132
Cdd:pfam00018   1 VALYDYTAQEPDELSFKKGDIIIVLEKSEDGWWKGRnKGGKEGLIPS 47

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  88 AKFNFQQTNEDELSFAKGDVIHV-TRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11830    4 ARYDFCARDMRELSLKEGDVVKIyNKKGQQGWWRGEINGRIGWFPSTYVEE 54

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11772    1 VFRALYDYEAQHPDELSFEEGDLLYISDKSDPNWWKATCGGKTGLIPSNYVEE 53

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  87 RAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd12055    3 QVAFSYLPQNEDELELKVGDIIEVVGEVEEGWWEGVLNGKTGMFPSNFIKE 53

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGR-TGWFPSNYVRE 137
Cdd:cd11825    2 VKALYDYRAQRPDELSFCKHAIITNVEKEDGGWWRGDYGGKkQKWFPANYVEE 54

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.

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                 ....*....|....*....|....*....|....*....|....*....|
gi 528972046  87 RAKFNFQQTNEDELSFAKGDVIHVT-RVEEGgWWEGTHNGRTGWFPSNYV 135
Cdd:cd11803    4 RALYDFEPENEGELGFKEGDIITLTnQIDEN-WYEGMVNGQSGFFPVNYV 52

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVR 136
Cdd:cd11949    2 VQALFDFDPQEDGELGFRRGDFIEVMDNSDPNWWKGACHGQTGMFPRNYVT 52

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTG-WFPSNYVREV 138
Cdd:cd11970    6 VKALFDYKAQREDELTFTKNAIIQNVEKQEGGWWRGDYGGKKQlWFPSNYVEEI 59

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.

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                 ....*....|....*....|....*....|....*....|....*....|...
gi 528972046  85 VVRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11837    1 TATALYPWRAKKENHLSFAKGDIITVLEQQEMWWFGELEGGEEGWFPKSYVKE 53

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.

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                 ....*....|....*....|....*....|....*....|....*....|....*.
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEG----GWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11762    2 VRALYDYEAQSDEELSFPEGAIIRILRKDDNgvddGWWEGEFNGRVGVFPSLVVEE 57

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*
gi 528972046  88 AKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPS 132
Cdd:cd11832    4 AVKSYSPQEEGEISLHKGDRVKVLSIGEGGFWEGSVRGRTGWFPS 48

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.

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                 ....*....|....*....|....*....|....*....|....*....|....
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTG-WFPSNYVREV 138
Cdd:cd11969    2 VKALYDYRAKRSDELSFCKGALIHNVSKETGGWWKGDYGGKVQhYFPSNYVEDV 55

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.

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                 ....*....|....*....|....*....|....*....|....*....|.
gi 528972046  88 AKFNFQQTNEDELSFAKGDVIHV-TRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11978    5 ARYDFCARDMRELSLLKGDVVKIyTKMSTNGWWRGEVNGRVGWFPSTYVEE 55

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

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 528972046  87 RAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYV 135
Cdd:cd11921    4 RLKFDFQAQSPKELTLQKGDIVYIHKEVDKNWLEGEHHGRVGIFPANYV 52

Unstructured region one on RhoGEF 6 and 7; RhoGEF67_u1 is a region of natively unstructured residues on Rho guanine nucleotide exchange factor 6 and 7 proteins. The function is not known. It lies between the CH and the SH3 domains.

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gi 528972046   35 GSDSVCARPSSHRIKSFDSLGPQPAHGRTSQLFQGQYRSLDMTDNSN 81
Cdd:pfam16615   1 GSERPCSRSSSSSRKSFSSLNSQSSSSRSSKSLRRQSKSVEMSENGG 47

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.

                         10        20        30        40
                 ....*....|....*....|....*....|....*....|....*....
gi 528972046  89 KFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGTHNGRTGWFPSNYVRE 137
Cdd:cd11902    6 KFAYVAEREDELSLVKGSRVTVMEKCSDGWWRGSYNGQIGWFPSNYVVE 54

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.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 528972046  86 VRAKFNFQQTN-EDELSFAKGDVIHVTRV-----EEGGWWEG-THNGRTGWFPSNYV 135
Cdd:cd11771    2 CRALYDFTPENpEMELSLKKGDIVAVLSKtdplgRDSEWWKGrTRDGRIGWFPSNYV 58

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

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 528972046  86 VRAKFNFQQTNEDELSFAKGDVIHVTRVEEGGWWEGT--HNGRTGWFPSNYVRE 137
Cdd:cd11793    2 VQCVHAYTAQQPDELTLEEGDVVNVLRKMPDGWYEGErlRDGERGWFPSSYTEE 55