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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1011596997 241 QTLRAIFQYKPQNIDELMLNAGDLIFVDRTQQSDVSEGWVIGTSHRTGCRGFLPENYTER 300
Cdd:cd11937     1 QTLRALFQYKPQNIDELMLSPGDYIFVDPTQQSEASEGWVIGISHRTGCRGFLPENYTER 60

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.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1011596997 241 QTLRAIFQYKPQNIDELMLNAGDLIFVDRTQQSDVSEGWVIGTSHRTGCRGFLPENYTER 300
Cdd:cd11937     1 QTLRALFQYKPQNIDELMLSPGDYIFVDPTQQSEASEGWVIGISHRTGCRGFLPENYTER 60

Variant SH3 domain;

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1011596997 245 AIFQYKPQNIDELMLNAGDLIFVDRtqqsDVSEGWVIGTshRTGCRGFLPENYTE 299
Cdd:pfam14604   1 ALYPYEPKDDDELSLQRGDVITVIE----ESEDGWWEGI--NTGRTGLVPANYVE 49

UBA/TS-N domain; This small domain is composed of three alpha helices. This family includes the previously defined UBA and TS-N domains. The UBA-domain (ubiquitin associated domain) is a novel sequence motif found in several proteins having connections to ubiquitin and the ubiquitination pathway. The structure of the UBA domain consists of a compact three helix bundle. This domain is found at the N terminus of EF-TS hence the name TS-N. The structure of EF-TS is known and this domain is implicated in its interaction with EF-TU. The domain has been found in non EF-TS proteins such as alpha-NAC and MJ0280.

                          10        20        30
                  ....*....|....*....|....*....|....*
gi 1011596997  23 STVEPLLAMGFPAHTVQKALAATGrKTIEDATKWL 57
Cdd:pfam00627   4 EAIQRLVEMGFDREQVREALRATG-NNVERAAEYL 37

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.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1011596997 241 QTLRAIFQYKPQNIDELMLNAGDLIFVDRTQQSDVSEGWVIGTSHRTGCRGFLPENYTER 300
Cdd:cd11937     1 QTLRALFQYKPQNIDELMLSPGDYIFVDPTQQSEASEGWVIGISHRTGCRGFLPENYTER 60

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1011596997 240 YQTLRAIFQYKPQNIDELMLNAGDLIFVDRTQQSDVSEGWVIGTSHRTGCRGFLPENYTERA 301
Cdd:cd11936     1 HETLQVIYPYTPQNDDELELVPGDYIFMSPMEQTSTSEGWIYGTSLTTGCSGLLPENYITKA 62

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVdrTQQSDvsEGWVIGTSHRTGCRGFLPENYTER 300
Cdd:cd11780     3 RALYSYTPQNEDELELREGDIVYV--MEKCD--DGWFVGTSERTGLFGTFPGNYVAR 55

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDRTQ-QSDVSEGWVIGTSHRTGCRGFLPENYTER 300
Cdd:cd11790     4 KVRATHDYTAEDTDELTFEKGDVILVIPFDdPEEQDEGWLMGVKESTGCRGVFPENFTER 63

UBA domain found in ubiquitin-associated and SH3 domain-containing protein B (UBS3B) and similar proteins; UBS3B, or Cbl-interacting protein p70, suppressor of T-cell receptor signaling 1 (Sts-1), T-cell ubiquitin ligand 2 (TULA-2), or tyrosine-protein phosphatase STS1/TULA2, is ubiquitously expressed in mammalian tissues in a variety of cell types. It exhibits high phosphatase activity, but demonstrates no proapoptotic activity. It negatively regulates the tyrosine kinase Zap-70 activation and T cell receptor (TCR) signaling pathways that modulate T cell activation. Moreover, UBS3B acts as a Cbl- and ubiquitin-interacting protein that inhibits endocytosis of epidermal growth factor receptor (EGFR) and platelet-derived growth factor receptor.

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                  ....*....|....*....|....*....|....*...
gi 1011596997  23 STVEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSH 60
Cdd:cd14301     1 SALEVLLSMGFPKHRAEKALAATGGRSVQLASDWLLSH 38

UBA domain found in UBX domain-containing protein 1 (UBXN1) and similar proteins; UBXN1, also called SAPK substrate protein 1 (SAKS1) or UBA/UBX 33.3 kDa protein, is a widely expressed protein containing an N-terminal ubiquitin-associated (UBA) domain, a coiled-coil region, and a C-terminal ubiquitin-like (UBX) domain. It binds polyubiquitin and valosin-containing protein (VCP), and has been identified as a substrate for stress-activated protein kinases (SAPKs). Moreover, UBXN1 specifically binds to Homer2b. It may also interact with ubiquitin (Ub) and may be involved in the Ub-proteasome proteolytic pathways. In addition, UBXN1 can associate with autoubiquitinated BRCA1 tumor suppressor and inhibit its enzymatic function through its UBA domain.

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                  ....*....|....*....|....*....|....*....|.
gi 1011596997  23 STVEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSHCND 63
Cdd:cd14302     1 SELQTLIEMGFSRNRAEKALAKTGNQGVEAAMEWLLAHEDD 41

UBA1 domain found in Schizosaccharomyces pombe ubiquitin carboxyl-terminal hydrolase 14 (spUBP14) and similar proteins; spUBP14, also called deubiquitinating enzyme 14, UBA domain-containing protein 2, ubiquitin thioesterase 14, or ubiquitin-specific-processing protease 14, functions as a deubiquitinating enzyme that is involved in protein degradation in fission yeast. Members in this family contain two tandem ubiquitin-association (UBA) domains. This model corresponds to the UBA1 domain.

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                  ....*....|....*....|....*....|....*....|...
gi 1011596997  25 VEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSHCNDPSLD 67
Cdd:cd14385     5 LAQLLGMGFPEVRCKKALLATGNSDAEAAMNWLFEHMDDPDID 47

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFvdRTQQSDvsEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11934     6 RAVYDYNAADEDEVSFQDGDTIV--NVQQID--DGWMYGTVERTGDTGMLPANYVE 57

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1011596997 241 QTLRAIFQYKPQNIDELMLNAGDLIFVDRTqqsdVSEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11933     2 KSFRAMYDYRAADDDEVSFKDGDTIVNVQT----IDEGWMYGTVQRTGKTGMLPANYVE 56

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIfvdrTQQSDVSEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11789     1 RYRAMYDYAAADDDEVSFQEGDVI----INVEIIDDGWMEGTVQRTGQSGMLPANYVE 54

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

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRTQQsdvsEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11785     3 RVIVPYPPQSEAELELKEGDIVFVHKKRE----DGWFKGTLQRTGKTGLFPGSFVE 54

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRtqqSDVSEGWVIGTSHRtGCRGFLPENYTE 299
Cdd:cd11763     3 RALYDFDSQPSGELSLRAGEVLTITR---QDVGDGWLEGRNSR-GEVGLFPSSYVE 54

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRTQQSDvsEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd12142     3 RVLFDYNPVAPDELALKKGDVIEVISKETED--EGWWEGELN--GRRGFFPDNFVM 54

UBA1 domain found in Arabidopsis thaliana ubiquitin carboxyl-terminal hydrolase 14 (atUBP14) and similar proteins; atUBP14, also called deubiquitinating enzyme 14, TITAN-6 protein, ubiquitin thioesterase 14, or ubiquitin-specific-processing protease 14, is related to the isopeptidase T class of deubiquitinating enzymes that recycle polyubiquitin chains following protein degradation. atUBP14 is essential for early plant development. It can disassemble multi-ubiquitin chains linked internally via epsilon-amino isopeptide bonds using Lys48 and can process some, but not all, translational fusions of ubiquitin linked via alpha-amino peptide bonds. atUBP14 contains two ubiquitin-association (UBA) domains. This model corresponds to the UBA1 domain.

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                  ....*....|....*....|....*....|....*....|.
gi 1011596997  25 VEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSHCNDPS 65
Cdd:cd14295     5 VAQLMEMGFPKVRAEKALFFTQNKGLEEAMEWLEEHSEDAD 45

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1011596997 245 AIFQYKPQNIDELMLNAGDLIFVDRtqqsDVSEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11793     4 CVHAYTAQQPDELTLEEGDVVNVLR----KMPDGWYEGERLRDGERGWFPSSYTE 54

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRTQqsdvSEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd11823     3 KALYSYTANREDELSLQPGDIIEVHEKQ----DDGWWLGELN--GKKGIFPATYVE 52

Src homology 3 domain of JNK-interacting proteins 1 and 2, and similar domains; JNK-interacting proteins (JIPs) function as scaffolding proteins for c-Jun N-terminal kinase (JNK) signaling pathways. They bind to components of Mitogen-activated protein kinase (MAPK) pathways such as JNK, MKK, and several MAP3Ks such as MLK and DLK. There are four JIPs (JIP1-4); all contain a JNK binding domain. JIP1 and JIP2 also contain SH3 and Phosphotyrosine-binding (PTB) domains. Both are highly expressed in the brain and pancreatic beta-cells. JIP1 functions as an adaptor linking motor to cargo during axonal transport and also is involved in regulating insulin secretion. JIP2 form complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. The SH3 domain of JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDRTQQsdvsEGWVIGTSHRTGCRGFLPENY 297
Cdd:cd11801     1 THRALHKFIPRHEDEIELDIGDPVYVEQEAD----DLWCEGTNLRTGQRGIFPAAY 52

Src Homology 3 domain of Bridging integrator 1 (Bin1), also called Amphiphysin-2; Bin1 isoforms are localized in many different tissues and may function in intracellular vesicle trafficking. It plays a role in the organization and maintenance of the T-tubule network in skeletal muscle. Mutations in Bin1 are associated with autosomal recessive centronuclear myopathy. Bin1 contains an N-terminal BAR domain with an additional N-terminal amphipathic helix (an N-BAR) and a C-terminal SH3 domain. The SH3 domain of Bin1 forms transient complexes with actin, myosin filaments, and CDK5, to facilitate sarcomere organization and myofiber maturation. It also binds dynamin and prevents its self-assembly. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles 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 1011596997 243 LRAIFQYKPQNIDELMLNAGDLIFVDRTQQSD-VSEGWVIGTSHR--------TGCRGFLPENYTER 300
Cdd:cd12139     5 VQAQHDYTATDTDELQLKAGDVVLVIPFQNPEeQDEGWLMGVKESdwnqhkklEKCRGVFPENFTER 71

UBA1 domain found in ubiquitin carboxyl-terminal hydrolase UBP5, UBP13 and similar proteins; UBP5, also called deubiquitinating enzyme 5, Isopeptidase T (IsoT), ubiquitin thioesterase 5, or ubiquitin-specific-processing protease 5, is a deubiquitinating enzyme largely responsible for the disassembly of the majority of unanchored polyubiquitin in the cell. Zinc is required for its catalytic activity. UBP5 contains four ubiquitin (Ub)-binding sites including an N-terminal zinc finger (ZnF) domain, a catalytic ubiquitin-specific processing protease (UBP) domain (catalytic C-box and H-box), and two ubiquitin-associated (UBA) domains. ZnF domain binds the proximal ubiquitin. UBP domain forms the active site. UBA domains are involved in binding linear or K48-linked polyubiquitin. UBP13, also called deubiquitinating enzyme 13, Isopeptidase T-3 (isoT3), ubiquitin thioesterase 13, or ubiquitin-specific-processing protease 13, is an ortholog of UBP5. It has similar domain architecture, but functions differently from USP5 in cellular deubiquitination processes. It exhibits a weak deubiquitinating activity preferring to Lys63-linked polyubiquitin in a non-activation manner. Moreover, the zinc finger (ZnF) domain of USP13 cannot bind to Ub. Its tandem UBA domains can bind with different types of diUb but preferentially with K63-linked.USP13 can also regulate the protein level of CD3delta in cells via its UBA domains. This model corresponds to the UBA1 domain.

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gi 1011596997  23 STVEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSHCNDP 64
Cdd:cd14294     2 AVVSQLAEMGFPLEACRKAVYHTNNSGLEAAMNWIMEHMDDP 43

Src homology 3 domain of the Rho guanine nucleotide exchange factors ARHGEF5 and ARHGEF19; ARHGEF5, also called ephexin-3 or TIM (Transforming immortalized mammary oncogene), is a potent activator of RhoA and it plays roles in regulating cell shape, adhesion, and migration. It binds to the SH3 domain of Src and is involved in regulating Src-induced podosome formation. ARHGEF19, also called ephexin-2 or WGEF (weak-similarity GEF), is highly expressed in the intestine, liver, heart and kidney. It activates RhoA, Cdc42, and Rac 1, and has been shown to activate RhoA in the Wnt-PCP (planar cell polarity) pathway. It is involved in the regulation of cell polarity and cytoskeletal reorganization. ARHGEF5 and ARHGEF19 contain RhoGEF (also called Dbl-homologous or DH), Pleckstrin Homology (PH), and SH3 domains. The SH3 domains of ARHGEFs play an autoinhibitory role through intramolecular interactions with a proline-rich region N-terminal to the DH domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1011596997 241 QTLRAifqYKPQNIDELMLNAGDLIFVdrTQQSdvSEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11940     3 QCIRS---YKAQENDELTLEKADIIMV--RQQS--SDGWLEGVRLSDGERGWFPQSHVE 54

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDRtqqSDVSEGWVIGTSHrtGCRGFLPENY 297
Cdd:cd11778     1 YVEALYDYEAQGDDEISIRVGDRIAVIR---GDDGSGWTYGEIN--GVKGLFPTSY 51

Src homology 3 domain of JNK-interacting protein 2; JNK-interacting protein 2 (JIP2) is also called Mitogen-activated protein kinase 8-interacting protein 2 (MAPK8IP2) or Islet-brain-2 (IB2). It is widely expressed in the brain, where it forms complexes with fibroblast growth factor homologous factors (FHFs), which facilitates activation of the p38delta MAPK. JIP2 is enriched in postsynaptic densities and may play a role in motor and cognitive function. In addition to a JNK binding domain, JIP2 also contains SH3 and Phosphotyrosine-binding (PTB) domains. The SH3 domain of the related protein JIP1 homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDRTQqsdvSEGWVIGTSHRTGCRGFLPENY 297
Cdd:cd11942     1 THRAVFRFIPRHEDELELDVDDPLLVEAEE----DDYWYRGYNMRTGERGIFPAFY 52

UBA1 domain found in ubiquitin carboxyl-terminal hydrolase 5 (UBP5); UBP5, also called deubiquitinating enzyme 5, Isopeptidase T (IsoT), ubiquitin thioesterase 5, or ubiquitin-specific-processing protease 5, is a deubiquitinating enzyme largely responsible for the disassembly of the majority of unanchored polyubiquitin in the cell. Zinc is required for its catalytic activity. UBP5 contains four ubiquitin (Ub)-binding sites including an N-terminal zinc finger (ZnF) domain, a catalytic ubiquitin-specific processing protease (UBP) domain (catalytic C-box and H-box), and two ubiquitin-associated (UBA) domains. ZnF domain binds the proximal ubiquitin. UBP domain forms the active site. UBA domains are involved in binding linear or K48-linked polyubiquitin. This model corresponds to the UBA1 domain.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 1011596997  23 STVEPLLAMGFPAHTVQKALAATGRKTIEDATKWLHSHCNDP 64
Cdd:cd14383     5 SVIIQLVEMGFPMDACRKAVYYTGNSGAEAAMNWVMSHMDDP 46

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRTQQSDvsEGWVIGtsHRTGCRGFLPENYTER 300
Cdd:cd11987     3 RALYPFEARSHDEITIQPGDIVMVDESQTGE--PGWLGG--ELKGKTGWFPANYAEK 55

Src homology 3 domain of JNK-interacting protein 1; JNK-interacting protein 1 (JIP1) is also called Islet-brain 1 (IB1) or Mitogen-activated protein kinase 8-interacting protein 1 (MAPK8IP1). It is highly expressed in neurons, where it functions as an adaptor linking motor to cargo during axonal transport. It also affects microtubule dynamics in neurons. JIP1 is also found in pancreatic beta-cells, where it is involved in regulating insulin secretion. In addition to a JNK binding domain, JIP1 also contains SH3 and Phosphotyrosine-binding (PTB) domains. Its SH3 domain homodimerizes at the interface usually involved in proline-rich ligand recognition, despite the lack of this motif in the domain itself. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDrTQQSDVsegWVIGTSHRTGCRGFLPENY 297
Cdd:cd11943     1 THRAVFRFVPRHPDELELEVDDPLLVE-VQAEDY---WYEAYNMRTGARGIFPAYY 52

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 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVdrtqQSDVSEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd12055     3 QVAFSYLPQNEDELELKVGDIIEV----VGEVEEGWWEGVLN--GKTGMFPSNFIK 52

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 243 LRAIFQYKPQNIDELMLNAGDLIFVDRTQQSdvseGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd12060     4 VKARFNFKQTNEDELSVCKGDIIYVTRVEEG----GWWEGTLN--GKTGWFPSNYVR 54

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.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDR--TQQSDVS---------EGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11776     4 RALYDYEKERDEDIILKTGDVLVVENpeLLALGVPdgketvpkpEGWLEGKNERTGERGDFPGTYVE 70

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIFVDRTQQSdvseGW---VIGTSHRTGCRGFLPENY 297
Cdd:cd11883     1 VVVALYDFTPKSKNQLSFKAGDIIYVLNKDPS----GWwdgVIISSSGKVKRGWFPSNY 55

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 244 RAIFQY-KPQNIDELMLNAGDLIFVdrtqQSDVSEGWVIGTSHRTGCRGFLPENYTE 299
Cdd:cd11788     5 RAILPYnKVPDTDELSFQKGDIFVV----HNELEDGWLWVTSLRTGESGLVFRDLVE 57

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIfvdrTQQSDVSEGWVIGTSHrtGCRGFLPENY 297
Cdd:cd11873     1 EVIVEFDYDAEEPDELTLKVGDII----TNVKKMEEGWWEGTLN--GKRGMFPDNF 50

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1011596997 242 TLRAIFQYKPQNIDELMLNAGDLIfvDRTQQSDvSEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd11882     1 RARALYACKAEDESELSFEPGQII--TNVQPSD-EPGWLEGTLN--GRTGLIPENYVE 53

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIfvdrTQQSDVSEGWVIGTSHrtGCRGFLPENY 297
Cdd:cd11818     3 RALYDFTGENEDELSFKAGDII----TELESIDEEWMSGELR--GKSGIFPKNF 50

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1011596997 241 QTLRAIFQYKPQNIDELMLNAGDLIFvdRTQQSDvSEGWVIGTSHRtGCRGFLPENYTE 299
Cdd:cd11999     2 VRVRAVYDYTGQEPDELSFKAGEELL--KVEDED-EQGWCKGVTDG-GAVGLYPANYVE 56

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 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVdrTQQSDvsEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd11826     3 VALYDYTADKDDELSFQEGDIIYV--TKKND--DGWYEGVLN--GVTGLFPGNYVE 52

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|...
gi 1011596997 245 AIFQYKPQNIDELMLNAGDLIFVDRTQQsdvsEGWVIGTSHRTGCRGFLPENY 297
Cdd:cd11784     4 ALHSYSAHRPEELELQKGEGVRVLGKFQ----EGWLRGLSLVTGRVGIFPSNY 52

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*.
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIFVDRTqqsdVSEGWVIGTSHrtGCRGFLPENYTE 299
Cdd:cd11786     3 KALYNYEGKEPGDLSFKKGDIILLRKR----IDENWYHGECN--GKQGFFPASYVQ 52

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.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1011596997 243 LRAIFQYKPQNIDELMLNAGDLIFVdrTQQSDvsEGWVIGTSHrtGCRGFLPENYTER 300
Cdd:cd11805     2 VQALYDFNPQEPGELEFRRGDIITV--LDSSD--PDWWKGELR--GRVGIFPANYVQP 53

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.

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                  ....*....|....*....|....*....|....*....|....*....|...
gi 1011596997 245 AIFQYKPQNIDELMLNAGDLIFVdrTQQSDvSEGWVigTSHRTGCRGFLPENY 297
Cdd:cd11948     4 ALYSFQATESDELPFQKGDILKI--LNMED-DQNWY--KAELQGREGYIPKNY 51

UBA domain found in serine/threonine-protein kinase LATS and similar proteins; The LATS proteins family consists of two isoforms, LATS1 and LATS2, both of which are mammalian homologs of the Drosophila tumor suppressor gene lats/warts. LATS1, also called large tumor suppressor homolog 1, or WARTS protein kinase (warts), is a serine/threonine-protein kinase that highly conserved from fly to human. LATS2, also called kinase phosphorylated during mitosis protein, or large tumor suppressor homolog 2, or serine/threonine-protein kinase KPM, or Warts-like kinase, inhibits the G1/S transition and is essential for embryonic development, proliferation control and genomic integrity. LATS proteins contain an N-terminal ubiquitin-associated (UBA) domain and a C-terminal protein kinase domain.

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                  ....*....|....*....|....*....|...
gi 1011596997  25 VEPLLAMGFPAHTVQKALAATGRKTIEDATKWL 57
Cdd:cd14322     4 LQQLVAAGYSEEISMRALKKSGARTIEAAIEFI 36

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.

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                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1011596997 244 RAIFQYKPQNIDELMLNAGDLIfvdrTQQSDVSE-GWVIGtsHRTGCRGFLPENYTE 299
Cdd:cd11843     3 RALYDYEGQESDELSFKAGDIL----TKLEEEDEqGWCKG--RLDGRVGLYPANYVE 53

UBA domain found in vacuolar protein sorting-associated protein 13D (VP13D) and similar proteins; VP13D is a chorea-acanthocytosis (CHAC)-similar protein encoded by gene VPS13D. it contains two putative domains, ubiquitin-associated (UBA) domain and lectin domain of ricin B chain profile (ricin-B-lectin), suggesting it may interact with, and be involved in the trafficking of, proteins modified with ubiquitin and/or carbohydrate molecules. Further investigation is required.

                          10        20        30
                  ....*....|....*....|....*....|....*..
gi 1011596997  25 VEPLLAMGFPAHTVQKALAATGRKtIEDATKWLHSHC 61
Cdd:cd14306     1 VAKLMELGFPEEDCIRALRACGGN-VEEAANWLLENA 36