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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 425 IHRTQLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 504
Cdd:cd10413   1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                        90       100
                ....*....|....*....|....*...
gi 71979667 505 LLQLVEFHQLNRGILPCLLRHCCTRVAL 532
Cdd:cd10413  81 LLQLVEFHQLNRGILPCLLRHCCTRVAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 7; GRB7, also termed B47, or epidermal growth factor receptor GRB-7, or GRB7 adapter protein, is a signal-transducing cytoplasmic adaptor protein that is co-opted by numerous tyrosine kinases involved in various cellular signaling and functions. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb7 could interact with activated N-Ras in transfected cells.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 100 RPHVVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPVGGDSRF 179
Cdd:cd16140   1 GPHVVKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATWPAGGDSRF 80

                ....*...
gi 71979667 180 VFRKNFAK 187
Cdd:cd16140  81 VFRKNFAK 88

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 425 IHRTQLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 504
Cdd:cd10413   1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                        90       100
                ....*....|....*....|....*...
gi 71979667 505 LLQLVEFHQLNRGILPCLLRHCCTRVAL 532
Cdd:cd10413  81 LLQLVEFHQLNRGILPCLLRHCCTRVAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 7; GRB7, also termed B47, or epidermal growth factor receptor GRB-7, or GRB7 adapter protein, is a signal-transducing cytoplasmic adaptor protein that is co-opted by numerous tyrosine kinases involved in various cellular signaling and functions. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm. Grb7 could interact with activated N-Ras in transfected cells.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 100 RPHVVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPVGGDSRF 179
Cdd:cd16140   1 GPHVVKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATWPAGGDSRF 80

                ....*...
gi 71979667 180 VFRKNFAK 187
Cdd:cd16140  81 VFRKNFAK 88

BPS (Between PH and SH2); The BPS (Between PH and SH2) domain, comprised of 2 beta strands and a C-terminal helix, is an approximately 45 residue region found in the adaptor proteins Grb7/10/14 that mediates inhibition of the tyrosine kinase domain of the insulin receptor by binding of the N-terminal portion of the BPS domain to the substrate peptide groove of the kinase, acting as a pseudosubstrate inhibitor.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|....*.
gi 71979667   365 RSASDNTLVAMDFSGHAGRVIENPREALSVALEEAQAWRKKTNHRL 410
Cdd:pfam08947   1 RSVSESSLVAMDFSGAGGRVIENPEEALSEAEEEGAAWRKKTLRRC 46

Ras association (RalGDS/AF-6) domain; RasGTP effectors (in cases of AF6, canoe and RalGDS); putative RasGTP effectors in other cases. Kalhammer et al. have shown that not all RA domains bind RasGTP. Predicted structure similar to that determined, and that of the RasGTP-binding domain of Raf kinase. Predicted RA domains in PLC210 and nore1 found to bind RasGTP. Included outliers (Grb7, Grb14, adenylyl cyclases etc.)

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667    100 RPHVVKVYSED---GACRSVEVAAGATARHVCEMLVQRAHALSD-ETWGLVECHPHlALERGLEDHESVVEVQAAWPVGG 175
Cdd:smart00314   1 DTFVLRVYVDDlpgGTYKTLRVSSRTTARDVIQQLLEKFHLTDDpEEYVLVEVLPD-GKERVLPDDENPLQLQKLWPRRG 79

                           90
                   ....*....|
gi 71979667    176 DS-RFVFRKN 184
Cdd:smart00314  80 PNlRFVLRKR 89

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 71979667    230 PEIQGFLQLRGS-GRKLWKRFFCFLRRSGLYYSTKGTSKDPRHLQYVADVNESNVYVVTQGRKlygMPTDFGFcvkpnKL 308
Cdd:smart00233   1 VIKEGWLYKKSGgGKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTVREAPDPDS---SKKPHCF-----EI 72

                           90       100
                   ....*....|....*....|....*.
gi 71979667    309 RNGHKGLRIFCSEDEQSRTCWLAAFR 334
Cdd:smart00233  73 KTSDRKTLLLQAESEEEREKWVEALR 98

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 425 IHRTQLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 504
Cdd:cd10413   1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                        90       100
                ....*....|....*....|....*...
gi 71979667 505 LLQLVEFHQLNRGILPCLLRHCCTRVAL 532
Cdd:cd10413  81 LLQLVEFHQLNRGILPCLLRHCCTRVAL 108

Amyloid beta (A4) Precursor protein-Binding, family B, member 1 Interacting Protein pleckstrin homology (PH) domain; APBB1IP consists of a Ras-associated (RA) domain, a PH domain, a family-specific BPS region, and a C-terminal SH2 domain. Grb7, Grb10 and Grb14 are paralogs that are also present in this hierarchy. These adapter proteins bind a variety of receptor tyrosine kinases, including the insulin and insulin-like growth factor-1 (IGF1) receptors. Grb10 and Grb14 are important tissue-specific negative regulators of insulin and IGF1 signaling based and may contribute to type 2 (non-insulin-dependent) diabetes in humans. RA-PH function as a single structural unit and is dimerized via a helical extension of the PH domain. The PH domain here are proposed to bind phosphoinositides non-cannonically ahd are unlikely to bind an activated GTPase. The tandem RA-PH domains are present in a second adapter-protein family, MRL proteins, Caenorhabditis elegans protein MIG-1012, the mammalian proteins RIAM and lamellipodin and the Drosophila melanogaster protein Pico12, all of which are Ena/VASP-binding proteins involved in actin-cytoskeleton rearrangement. 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 71979667 225 NAGSFPEIQGFLQLRGSGRKLWKRFFCFLRRSGLYYSTKGTSKDPRHLQYVADVNESNVYVVTQGRKLYGMPTDFGFCVK 304
Cdd:cd01259   1 NSVSCPEIEGFLYLKEDGKKSWKKRYFVLRASGLYYSPKGKSKESRDLQCLAQFDDYNVYTGLNGKKKYKAPTDFGFCLK 80

                        90       100       110       120
                ....*....|....*....|....*....|....*....|....
gi 71979667 305 PNKLR-NGHKGLRIFCSEDEQSRTCWLAAFRLFKYGVQLYKNYQ 347
Cdd:cd01259  81 PNKQQeKGSKDIKYLCAEDEQSRTCWLTAIRLAKYGKQLYENYR 124

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 425 IHRTQLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 504
Cdd:cd10414   1 IHRSQPWFHHKISRDEAQRLIIQQGLVDGVFLVRDSQSNPRTFVLSMSHGQKIKHFQIIPVEDDGELFHTLDDGHTRFTD 80

                        90       100
                ....*....|....*....|....*...
gi 71979667 505 LLQLVEFHQLNRGILPCLLRHCCTRVAL 532
Cdd:cd10414  81 LIQLVEFYQLNKGVLPCKLKHYCARIAL 108

Ras-associating (RA) domain found in growth factor receptor-bound (Grb) protein 7/10/14; The RA domain is highly conserved among the members of the Grb proteins family which includes Grb7, Grb10 and Grb14. Grb7/10/14 are multi-domain cytoplasmic adaptor proteins that are recruited to activated receptor tyrosine kinases. RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 101 PHVVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPVGGDSRFV 180
Cdd:cd16124   1 KQVVKVYSEDGTSRSVEVAADATARDVCQLLVQKAHALDDESWTLVEHHPHLGLERGLEDHELVVEVQSAWPVGGESKFV 80

                ....*
gi 71979667 181 FRKNF 185
Cdd:cd16124  81 FRKNY 85

Ras-associating (RA) domain found in Mig10/RIAM/Lpd (MRL) family and growth factor receptor-bound (Grb) protein 7/10/14; MRL proteins share a common structural architecture, including a central structural unit consisting of a Ras-associating (RA) domain and a pleckstrin homology (PH) domain, an upstream coiled-coil region, and a number of polyproline motifs. RA domain-containing proteins function by interacting with Ras proteins directly or indirectly and are involved in several different functions ranging from tumor suppression to being oncoproteins. Ras proteins are small GTPases that are involved in cellular signal transduction. RA domain has the beta-grasp ubiquitin-like (Ubl) fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. RA and PH form a tandem domain pair (RA-PH), and serve tightly coordinated functions in both Ras GTPase signaling via the RA domain and membrane translocalization via the PH domain. MRL proteins have distinct functions in cell migration and adhesion, signaling, and in cell growth. Grb7/10/14 are multi-domain cytoplasmic adaptor proteins that are recruited to activated receptor tyrosine kinases. Grb7 and its related family members Grb10 and Grb14 share a conserved domain architecture that includes an amino-terminal proline-rich region, a central segment termed the GM region (for Grb and Mig) which includes the RA, PIR, and pleckstrin homology (PH) domains, and a carboxyl-terminal SH2 domain. The tandem RA and PH domains of Grb7/10/14 are also found in a second adaptor family, Rap1-interacting adaptor molecule (RIAM) and lamellipodin, which is involved in actin-cytoskeleton rearrangement. Grb7/10/14 family proteins are phosphorylated on serine/threonine as well as tyrosine residues and are mainly localized to the cytoplasm.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 103 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPVGGDSRFVFR 182
Cdd:cd17112   1 VVKVYNEDGSSKTVAVDENMTARDVCQILVEKNHVDPDKSWSLVEELPELGLERTLEDHELVVDVYSKWPSDSNNKFLFR 80

                .
gi 71979667 183 K 183
Cdd:cd17112  81 K 81

Src homology 2 domains; Src homology 2 domains bind phosphotyrosine-containing polypeptides via 2 surface pockets. Specificity is provided via interaction with residues that are distinct from the phosphotyrosine. Only a single occurrence of a SH2 domain has been found in S. cerevisiae.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667    429 QLWFHGRISREESQRLIGQQGlvDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSeEEGRLYFsmdDGQTRFTDLLQL 508
Cdd:smart00252   1 QPWYHGFISREEAEKLLKNEG--DGDFLVRDSESSPGDYVLSVRVKGKVKHYRIRRN-EDGKFYL---EGGRKFPSLVEL 74

                   ....*...
gi 71979667    509 VEFHQLNR 516
Cdd:smart00252  75 VEHYQKNS 82

SH2 domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667   431 WFHGRISREESQRLIgQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILpSEEEGRLYFSmddGQTRFTDLLQLVE 510
Cdd:pfam00017   1 WYHGKISRQEAERLL-LNGKPDGTFLVRESESTPGGYTLSVRDDGKVKHYKIQ-STDNGGYYIS---GGVKFSSLAELVE 75

                  ..
gi 71979667   511 FH 512
Cdd:pfam00017  76 HY 77

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIgqQGLVDGLFLVRESQRNPQGFVLSLCH-LQKVKHYLILPSEEEgrlYFSMDDGQTRFTDLLQLV 509
Cdd:cd00173   2 WFHGSISREEAERLL--RGKPDGTFLVRESSSEPGDYVLSVRSgDGKVKHYLIERNEGG---YYLLGGSGRTFPSLPELV 76

                ...
gi 71979667 510 EFH 512
Cdd:cd00173  77 EHY 79

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIGQQGlvDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSeeEGRLyfSMDDGQTrFTDLLQLVE 510
Cdd:cd09937   5 WFHGKISREEAERLLQPPE--DGLFLVRESTNYPGDYTLCVSFEGKVEHYRVIYR--NGKL--TIDEEEY-FENLIQLVE 77

                        90
                ....*....|....*....
gi 71979667 511 FHQLNRGILpcllrhcCTR 529
Cdd:cd09937  78 HYTKDADGL-------CTR 89

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 429 QLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLIlpsEEEGRLYFSMDDGQTRFTDLLQL 508
Cdd:cd10347   1 LRWYHGKISREVAEALLLREGGRDGLFLVRESTSAPGDYVLSLLAQGEVLHYQI---RRHGEDAFFSDDGPLIFHGLDTL 77

                ....
gi 71979667 509 VEFH 512
Cdd:cd10347  78 IEHY 81

Ras-associating (RA) domain of Mig10/RIAM/Lpd (MRL) family; MRL proteins share a common structural architecture, including a central structural unit consisting of a Ras-associating (RA) domain and a pleckstrin homology (PH) domain, an upstream coiled-coil region, and a number of polyproline motifs. RA domain-containing proteins function by interacting with Ras proteins directly or indirectly and are involved in several different functions ranging from tumor suppression to being oncoproteins. Ras proteins are small GTPases that are involved in cellular signal transduction. RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. RA and PH form a tandem domain pair (RA-PH), and serve tightly coordinated functions in both Ras GTPase signaling via the RA domain and membrane translocalization via the PH domain. MRL proteins have distinct functions in cell migration and adhesion, signaling, and in cell growth.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 71979667 103 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAW 171
Cdd:cd01787   3 VVKVHMEDGSSKTLLVDERMTVRQVLKQLIEKNHCDPSVDWCLVEQYPDLYMERVFEDHEKLVENLLNW 71

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 426 HRTQLWFHGRISREESQRLIGQQGLVDGLFLVREsqRNPQG-FVLSLCHLQKVKHYLILpSEEEGRlyFSMDDGqTRFTD 504
Cdd:cd10402   7 HERMPWYHGSIARDEAERRLYSGAQPDGKFLLRE--RKESGtYALSLVYGKTVYHYRID-QDKSGK--YSIPEG-TKFDT 80

                        90       100
                ....*....|....*....|...
gi 71979667 505 LLQLVEFHQLNR-GILPCLLRHC 526
Cdd:cd10402  81 LWQLVEYLKLKPdGLIFVLRESC 103

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 71979667    230 PEIQGFLQLRGS-GRKLWKRFFCFLRRSGLYYSTKGTSKDPRHLQYVADVNESNVYVVTQGRKlygMPTDFGFcvkpnKL 308
Cdd:smart00233   1 VIKEGWLYKKSGgGKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTVREAPDPDS---SKKPHCF-----EI 72

                           90       100
                   ....*....|....*....|....*.
gi 71979667    309 RNGHKGLRIFCSEDEQSRTCWLAAFR 334
Cdd:smart00233  73 KTSDRKTLLLQAESEEEREKWVEALR 98

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIgQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILpSEEEGRLYFsmddGQTRFTDLLQLVE 510
Cdd:cd09941   5 WFHGKISRAEAEEIL-MNQRPDGAFLIRESESSPGDFSLSVKFGNDVQHFKVL-RDGAGKYFL----WVVKFNSLNELVD 78

                ...
gi 71979667 511 FHQ 513
Cdd:cd09941  79 YHR 81

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSL-----CHLQKVKHYLIlPSEEEGRLYFSmddgqTR--FT 503
Cdd:cd09933   5 WFFGKIKRKDAEKLLLAPGNPRGTFLIRESETTPGAYSLSVrdgddARGDTVKHYRI-RKLDNGGYYIT-----TRatFP 78

                        90       100
                ....*....|....*....|
gi 71979667 504 DLLQLVEFHQLNRGILPCLL 523
Cdd:cd09933  79 TLQELVQHYSKDADGLCCRL 98

Ras-associating (RA) domain found in Caenorhabditis elegans abnormal cell migration protein 10 (MIG-10) and similar proteins; MIG-10 is lamellipodin (Lpd) found in C. elegans. It stabilizes invading cell adhesion to basement membrane and is a negative transcriptional target of Evi-1 proto-oncogene, EGL-43, in C. elegans. It also shows netrin-independent functions and is a transcriptional target of FOS-1A, a transcription factor that promotes basement membrane breaching, during anchor cell invasion in C. elegans. MIG-10 is a member of MRL (Mig10/RIAM/Lpd) family of proteins that is involved in antero-posterior migration of embryonic neurons CAN (canalassociated neurons), ALM (anterior lateral microtubule cells) and HSN (hermaphrodite-specific neurons). MRL proteins share a common structural architecture, including a central structural unit consisting of an RA domain and a pleckstrin homology (PH) domain, an upstream coiled-coil region, and a number of polyproline motifs. RA domain-containing proteins function by interacting with Ras proteins directly or indirectly and are involved in several different functions ranging from tumor suppression to being oncoproteins. RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub). Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes. RA and PH form a tandem domain pair (RA-PH), and serve tightly coordinated functions in both Ras GTPase signaling via the RA domain and membrane translocalization via the PH domain.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 71979667 104 VKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPVGGDSRFVF 181
Cdd:cd16138   5 VKAFTEDGSAKSLLVDERMTVGHVTRLLADKNHVAMMPDWAIVEHIPDLYMERVYEDHEKLVENLMMWTRDSPNRLLF 82

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIGQQGLVDGLFLVREsQRNPQGFVLSLCHLQKVKHYLIlPSEEEGRLyfSMDDGQtRFTDLLQLVE 510
Cdd:cd10401   5 WFHGKISREESEQILLIGSKTNGKFLIRE-RDNNGSYALCLLHDGKVLHYRI-DKDKTGKL--SIPDGK-KFDTLWQLVE 79

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 426 HRTQLWFHGRISREESQRLigqqgLV-DGLFLVRESQRNPQG---FVLSLCHLQKVKHYLIlpSEEEGRLYFSMDdgqTR 501
Cdd:cd10361   3 LENEPYYHGLLPREDAEEL-----LKnDGDFLVRKTEPKGGGkrkLVLSVRWDGKIRHFVI--NRDDGGKYYIEG---KS 72

                        90
                ....*....|..
gi 71979667 502 FTDLLQLVEFHQ 513
Cdd:cd10361  73 FKSISELINYYQ 84

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIGQQGlVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYfsmddGQTRFTDLLQLVE 510
Cdd:cd10340   2 WFHPVISGIEAENLLKTRG-VDGSFLARPSKSNPGDFTLSVRRGDEVTHIKIQNTGDYYDLY-----GGEKFATLSELVQ 75

                ....*....
gi 71979667 511 FHQLNRGIL 519
Cdd:cd10340  76 YYMEQHGQL 84

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 426 HRTQLWFHGRIS--REESQRLIGQ-QGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRL-YFSMDDGQtr 501
Cdd:cd10341   1 HFTEPWFHGKLGdgRDEAEKLLLEyCEGGDGTFLVRESETFVGDYTLSFWRNGKVQHCRIRSRQENGEKkYYLTDNLV-- 78

                        90
                ....*....|....*
gi 71979667 502 FTDLLQLVEFHQLNR 516
Cdd:cd10341  79 FDSLYELIDYYRQNP 93

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 429 QLWFHGRISREESQRLIGQQGlVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLIlpSEEEGRLYFsmddGQTRFTDLLQL 508
Cdd:cd09943   1 QPWYYGRITRHQAETLLNEHG-HEGDFLIRDSESNPGDYSVSLKAPGRNKHFKV--QVVDNVYCI----GQRKFHTMDEL 73

                ....*
gi 71979667 509 VEFHQ 513
Cdd:cd09943  74 VEHYK 78

Ras-associating (RA) domain found in Arf-GAP with Rho-GAP domain, ANK repeat and PH domain-containing proteins ARAP1, ARAP2, ARAP3, and similar proteins; ARAPs are phosphatidylinositol 3,4,5-trisphosphate (PtdIns(3,4,5)P(3))-dependent Arf Rap-activated guanosine triphosphatase (GTPase)-activating proteins (GAPs). They contain multiple functional domains, including ArfGAP and RhoGAP domains, as well as a sterile alpha motif (Sam) domain, five PH domains, and a RA domain. The RA domain has the beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin (Ub); Ub is a protein modifier in eukaryotes that is involved in various cellular processes including transcriptional regulation, cell cycle control, and DNA repair in eukaryotes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 104 VKVYSEDGACRSVEVAAGATARHVCEMLVQRAH-ALSDETWGLVECHPHLALERGLEDHESVVEVQAAWPV--GGDSRFV 180
Cdd:cd17113   8 VYIEEKEGTSVNIKVTPTMTAEEVVEQALNKKNlGGPEGNWALFEVIEDGGLERPLHESEKVLDVVLRWSQwpRKSNYLC 87

                ....
gi 71979667 181 FRKN 184
Cdd:cd17113  88 VKKN 91

Src homology 2 domain found in the SH2 domain containing protein 4A (SH2D4A); SH2D4A contains a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 431 WFHGRISREESQRLIGqqGLVDGLFLVRESQRnPQGFVLSLCHLQKVKHYLIlpsEEEGRLYFSMDDGQTRFTDLLQLVE 510
Cdd:cd10350   9 WFHGILTLKKANELLL--STMPGSFLIRVSEK-IKGYALSYLSEEGCKHFLI---DASADSYSFLGVDQLQHATLADLVE 82

                ...
gi 71979667 511 FHQ 513
Cdd:cd10350  83 YHK 85

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 432 FHGRISREESQRLIGqqGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYlilpseeegRLYFSMDD-----GQTRFTDLL 506
Cdd:cd10352   9 YHGLISREEAEQLLS--GASDGSYLIRESSRDDGYYTLSLRFNGKVKNY---------KLYYDGKNhyhyvGEKRFDTIH 77

                ...
gi 71979667 507 QLV 509
Cdd:cd10352  78 DLV 80

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

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 71979667 428 TQLWFHGRISREESQRLIGQQGLVDGLFLVRESQRNPQGFVLSLCHLQKVKHYLILPSeEEGRLYFsmdDGQTRFTDLLQ 507
Cdd:cd10358   1 SEPWFFGCISRSEAVRRLQAEGNATGAFLIRVSEKPSADYVLSVRDTQAVRHYKIWRR-AGGRLHL---NEAVSFLSLPE 76

                        90       100
                ....*....|....*....|
gi 71979667 508 LVEFHQ---LNRGI---LPC 521
Cdd:cd10358  77 LVNYHRaqsLSHGLrlaAPC 96