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 1958661224 428 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCLYFSMDDGQTRFTD 507
Cdd:cd10413     1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                          90       100
                  ....*....|....*....|....*...
gi 1958661224 508 LLQLVEFHQLNRGILPCLLRHCCARVAL 535
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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd16140     4 VVKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATWPAGGDSRFVFR 83

                  ....*
gi 1958661224 182 KNFAK 186
Cdd:cd16140    84 KNFAK 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 1958661224 428 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCLYFSMDDGQTRFTD 507
Cdd:cd10413     1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                          90       100
                  ....*....|....*....|....*...
gi 1958661224 508 LLQLVEFHQLNRGILPCLLRHCCARVAL 535
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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd16140     4 VVKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATWPAGGDSRFVFR 83

                  ....*
gi 1958661224 182 KNFAK 186
Cdd:cd16140    84 KNFAK 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 1958661224 368 RSVSDNTLVAMDFSGHAGRVIENPQEALSAATEEAQAWRKKTNHRL 413
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 1958661224  101 CVVKVYSED---GACRSVEVAAGATARHVCEMLVQRAHALSD-ENWGLVECHPyLALERGLEDHESVVEVQEAWPVGGDS 176
Cdd:smart00314   3 FVLRVYVDDlpgGTYKTLRVSSRTTARDVIQQLLEKFHLTDDpEEYVLVEVLP-DGKERVLPDDENPLQLQKLWPRRGPN 81

                   ....*...
gi 1958661224  177 -RFIFRKN 183
Cdd:smart00314  82 lRFVLRKR 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 1958661224  229 PEIQGFLQLRGSGrgsGRKLWKRFFCFLRRSGLYYSTKGTSKDPRHLQYVADINESNVYVVTQGRKLygiPTDFGFcvkp 308
Cdd:smart00233   1 VIKEGWLYKKSGG---GKKSWKKRYFVLFNSTLLYYKSKKDKKSYKPKGSIDLSGCTVREAPDPDSS---KKPHCF---- 70

                           90       100
                   ....*....|....*....|....*....
gi 1958661224  309 nKLRNGHKGLHIFCSEDEQSRTCWLSAFR 337
Cdd:smart00233  71 -EIKTSDRKTLLLQAESEEEREKWVEALR 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 1958661224 428 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCLYFSMDDGQTRFTD 507
Cdd:cd10413     1 IHRTQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEEEGRLYFSMDDGQTRFTD 80

                          90       100
                  ....*....|....*....|....*...
gi 1958661224 508 LLQLVEFHQLNRGILPCLLRHCCARVAL 535
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 1958661224 224 NAGSFPEIQGFLQLRGSGRgsgrKLWKRFFCFLRRSGLYYSTKGTSKDPRHLQYVADINESNVYVVTQGRKLYGIPTDFG 303
Cdd:cd01259     1 NSVSCPEIEGFLYLKEDGK----KSWKKRYFVLRASGLYYSPKGKSKESRDLQCLAQFDDYNVYTGLNGKKKYKAPTDFG 76

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....*...
gi 1958661224 304 FCVKPNKLR-NGHKGLHIFCSEDEQSRTCWLSAFRLFKYGVQLYKNYQ 350
Cdd:cd01259    77 FCLKPNKQQeKGSKDIKYLCAEDEQSRTCWLTAIRLAKYGKQLYENYR 124

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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd16140     4 VVKVYSEDGTCRSLEVTAGATARHVCEMLVQRAHCLDDESWSLVELHPHLALERCLEDHESVVEVQATWPAGGDSRFVFR 83

                  ....*
gi 1958661224 182 KNFAK 186
Cdd:cd16140    84 KNFAK 88

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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd16124     3 VVKVYSEDGTSRSVEVAADATARDVCQLLVQKAHALDDESWTLVEHHPHLGLERGLEDHELVVEVQSAWPVGGESKFVFR 82

                  ...
gi 1958661224 182 KNF 184
Cdd:cd16124    83 KNY 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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd17112     1 VVKVYNEDGSSKTVAVDENMTARDVCQILVEKNHVDPDKSWSLVEELPELGLERTLEDHELVVDVYSKWPSDSNNKFLFR 80

                  .
gi 1958661224 182 K 182
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 1958661224  432 QPWFHGRISREESQRLIGQQGlvDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGcLYFsmdDGQTRFTDLLQL 511
Cdd:smart00252   1 QPWYHGFISREEAEKLLKNEG--DGDFLVRDSESSPGDYVLSVRVKGKVKHYRIRRNEDGK-FYL---EGGRKFPSLVEL 74

                   ....*...
gi 1958661224  512 VEFHQLNR 519
Cdd:smart00252  75 VEHYQKNS 82

SH2 domain;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958661224 434 WFHGRISREESQRLIgQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILpSEDEGCLYFSmddGQTRFTDLLQLVE 513
Cdd:pfam00017   1 WYHGKISRQEAERLL-LNGKPDGTFLVRESESTPGGYTLSVRDDGKVKHYKIQ-STDNGGYYIS---GGVKFSSLAELVE 75

                  ..
gi 1958661224 514 FH 515
Cdd:pfam00017  76 HY 77

N-terminal Src homology 2 (SH2) domain found in Zeta-chain-associated protein kinase 70 (ZAP-70) and 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 N-terminus SH2 domains of both Syk and 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 1958661224 433 PWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLIlpsEDEGCLYFSMDDGQTrFTDLLQLV 512
Cdd:cd09938     2 PFFYGSITREEAEEYLKLAGMSDGLFLLRQSLRSLGGYVLSVCHGRKFHHYTI---ERQLNGTYAIAGGKA-HCGPAELC 77

                          90       100
                  ....*....|....*....|
gi 1958661224 513 EFHQLNRGILPCLLRHCCAR 532
Cdd:cd09938    78 EYHSTDLDGLVCLLRKPCNR 97

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 1958661224  101 CVVKVYSED---GACRSVEVAAGATARHVCEMLVQRAHALSD-ENWGLVECHPyLALERGLEDHESVVEVQEAWPVGGDS 176
Cdd:smart00314   3 FVLRVYVDDlpgGTYKTLRVSSRTTARDVIQQLLEKFHLTDDpEEYVLVEVLP-DGKERVLPDDENPLQLQKLWPRRGPN 81

                   ....*...
gi 1958661224  177 -RFIFRKN 183
Cdd:smart00314  82 lRFVLRKR 89

Src homology 2 (SH2) domain found in Abelson murine lymphosarcoma virus (ABL) proteins; ABL-family proteins are highly conserved tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. Several types of posttranslational modifications control ABL catalytic activity, subcellular localization, and stability, with consequences for both cytoplasmic and nuclear ABL functions. Binding partners provide additional regulation of ABL catalytic activity, substrate specificity, and downstream signaling. By combining this cassette with actin-binding and -bundling domain, ABL proteins are capable of connecting phosphoregulation with actin-filament reorganization. Vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions. ABL1 includes nuclear localization signals and a DNA binding domain which is used to mediate DNA damage-repair functions, while ABL2 has additional binding capacity for actin and for microtubules to enhance its cytoskeletal remodeling functions. SH2 is involved in several autoinhibitory mechanism that constrain the enzymatic activity of the ABL-family kinases. In one mechanism SH2 and SH3 cradle the kinase domain while a cap sequence stabilizes the inactive conformation resulting in a locked inactive state. Another involves phosphatidylinositol 4,5-bisphosphate (PIP2) which binds the SH2 domain through residues normally required for phosphotyrosine binding in the linker segment between the SH2 and kinase domains. The SH2 domain contributes to ABL catalytic activity and target site specificity. It is thought that the ABL catalytic site and SH2 pocket have coevolved to recognize the same sequences. Recent work now supports a hierarchical processivity model in which the substrate target site most compatible with ABL kinase domain preferences is phosphorylated with greatest efficiency. If this site is compatible with the ABL SH2 domain specificity, it will then reposition and dock in the SH2 pocket. This mechanism also explains how ABL kinases phosphorylates poor targets on the same substrate if they are properly positioned and how relatively poor substrate proteins might be recruited to ABL through a complex with strong substrates that can also dock with the SH2 pocket. 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 1958661224 433 PWFHGRISREESQRLIGQqgLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLIlpSEDEGCLYFSMDDgqTRFTDLLQLV 512
Cdd:cd09935     4 SWYHGPISRNAAEYLLSS--GINGSFLVRESESSPGQYSISLRYDGRVYHYRI--SEDSDGKVYVTQE--HRFNTLAELV 77

                          90
                  ....*....|....*.
gi 1958661224 513 EFHQLNRGILPCLLRH 528
Cdd:cd09935    78 HHHSKNADGLITTLRY 93

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 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAW 170
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 1958661224 429 HRTQPWFHGRISREESQRLIGQQGLVDGVFLVREsqRNPQG-FVLSLCHLQKVKHYLIlpSEDEGCLYfSMDDGqTRFTD 507
Cdd:cd10402     7 HERMPWYHGSIARDEAERRLYSGAQPDGKFLLRE--RKESGtYALSLVYGKTVYHYRI--DQDKSGKY-SIPEG-TKFDT 80

                          90       100
                  ....*....|....*....|...
gi 1958661224 508 LLQLVEFHQLNR-GILPCLLRHC 529
Cdd:cd10402    81 LWQLVEYLKLKPdGLIFVLRESC 103

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 1958661224 433 PWFHGRISREESQRLIgQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILpsEDEGCLYFSMddgQTRFTDLLQLV 512
Cdd:cd09941     4 PWFHGKISRAEAEEIL-MNQRPDGAFLIRESESSPGDFSLSVKFGNDVQHFKVL--RDGAGKYFLW---VVKFNSLNELV 77

                  ....
gi 1958661224 513 EFHQ 516
Cdd:cd09941    78 DYHR 81

Src homology 2 (SH2) domain found in SH2 adaptor protein C (SHC); SHC is involved in a wide variety of pathways including regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. An adapter protein, SHC has been implicated in Ras activation following the stimulation of a number of different receptors, including growth factors [insulin, epidermal growth factor (EGF), nerve growth factor, and platelet derived growth factor (PDGF)], cytokines [interleukins 2, 3, and 5], erythropoietin, and granulocyte/macrophage colony-stimulating factor, and antigens [T-cell and B-cell receptors]. SHC has been shown to bind to tyrosine-phosphorylated receptors, and receptor stimulation leads to tyrosine phosphorylation of SHC. Upon phosphorylation, SHC interacts with another adapter protein, Grb2, which binds to the Ras GTP/GDP exchange factor mSOS which leads to Ras activation. SHC is composed of an N-terminal domain that interacts with proteins containing phosphorylated tyrosines, a (glycine/proline)-rich collagen-homology domain that contains the phosphorylated binding site, and a C-terminal SH2 domain. SH2 has been shown to interact with the tyrosine-phosphorylated receptors of EGF and PDGF and with the tyrosine-phosphorylated C chain of the T-cell receptor, providing one of the mechanisms of T-cell-mediated Ras activation. 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958661224 430 RTQPWFHGRISREESQRLIGQqglvDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSE 489
Cdd:cd09925     5 RGEPWYHGKMSRRDAESLLQT----DGDFLVRESTTTPGQYVLTGMQNGQPKHLLLVDPE 60

C-terminal Src homology 2 (C-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): [SIVL]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 1958661224 434 WFHGRISREESQRLIGQQGlVDGVFLVRESQRNPQGFVLS-LCHLQKVKHYLIlpsedegclYFSMD----DGQTRFTDL 508
Cdd:cd09931     2 WFHGHLSGKEAEKLLLEKG-KPGSFLVRESQSKPGDFVLSvRTDDDKVTHIMI---------RCQGGkydvGGGEEFDSL 71

                          90
                  ....*....|
gi 1958661224 509 LQLVEFHQLN 518
Cdd:cd09931    72 TDLVEHYKKN 81

C-terminal Src homology 2 (C-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 1958661224 429 HRTQPWFHGRISREESQRLIGQQGLvDGVFLVRESQRNPQGFVLSLCHLQKVKHYLIlpsEDEGCLYFSmddGQTRFTDL 508
Cdd:cd09932     1 HESKEWFHANLTREQAEEMLMRVPR-DGAFLVRPSETDPNSFAISFRAEGKIKHCRI---KQEGRLFVI---GTSQFESL 73

                          90
                  ....*....|....*.
gi 1958661224 509 LQLVEF---HQLNRGI 521
Cdd:cd09932    74 VELVSYyekHPLYRKI 89

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 1958661224 103 VKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIF 180
Cdd:cd16138     5 VKAFTEDGSAKSLLVDERMTVGHVTRLLADKNHVAMMPDWAIVEHIPDLYMERVYEDHEKLVENLMMWTRDSPNRLLF 82

C-terminal Src homology 2 (SH2) domain found in Ras GTPase-activating protein 1 (GAP); RasGAP is part of the GAP1 family of GTPase-activating proteins. The protein is located in the cytoplasm and stimulates the GTPase activity of normal RAS p21, but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in RAS inactivation, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Alternative splicing results in two isoforms. The shorter isoform which lacks the N-terminal hydrophobic region, has the same activity, and is expressed in placental tissues. In general longer isoform contains 2 SH2 domains, a SH3 domain, a pleckstrin homology (PH) domain, and a calcium-dependent phospholipid-binding C2 domain. The C-terminus contains the catalytic domain of RasGap which catalyzes the activation of Ras by hydrolyzing GTP-bound active Ras into an inactive GDP-bound form of Ras. This model contains the C-terminal 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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1958661224 433 PWFHGRISREESQRLIGQQGlVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDE----GCLYF-SMDD 500
Cdd:cd10354     1 IWFHGKISREEAYNMLVKVG-GPGSFLVRESDNTPGDYSLSFRVNEGIKHFKIIPTGNNqfmmGGRYFsSLDD 72

Ras-associating (RA) domain found in Rap1-GTP-interacting adapter molecule (RIAM); RIAM, also termed amyloid beta A4 precursor protein-binding family B member 1-interacting protein, or APBB1-interacting protein 1, or proline-rich EVH1 ligand 1 (PREL-1), or proline-rich protein 73, or retinoic acid-responsive proline-rich protein 1 (RARP-1), is a member of MRL (Mig10/RIAM/Lpd) family proteins that regulates cell migration and promote lamellipodia protrusion in fibroblast by interacting with Ena/VASP proteins. RIAM regulates cell migration and mediates Rap1-induced cell adhesion. 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. RIAM also contains a helical region at the amino terminus for talin binding. 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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958661224 102 VVKVYSEDGACRSVEVAAGATARHVCEMLVQRAHALSDENWGLVECHPYLALERGLEDHESVVEVQEAWPVGGDSRFIFR 181
Cdd:cd16137     4 VVKVHMNDSSTKTLMVDERQTVRDVLDNLFEKTHCDCNVDWCLYEVNPELQIERFFEDHENVVEVLSDWTRDSENKVLFL 83

                  ....*.
gi 1958661224 182 KNFAKY 187
Cdd:cd16137    84 EKKEKY 89

Ras-associating (RA) domain, structurally similar to a beta-grasp ubiquitin-like fold; RA domain-containing proteins function by interacting with Ras proteins directly or indirectly and are involved in various functions ranging from tumor suppression to being oncoproteins. Ras proteins are small GTPases that are involved in cellular signal transduction. The 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. RA-containing proteins include RalGDS, AF6, RIN, RASSF1, SNX27, CYR1, STE50, and phospholipase C epsilon.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1958661224 102 VVKVYSED----GACRSVEVAAGATARHVCEMLVQRAH-ALSDENWGLVECHPYLALERGLEDHESVVEVQEAW-PVGGD 175
Cdd:cd17043     1 VLKVYDDDlapgSAYKSILVSSTTTAREVVQLLLEKYGlEEDPEDYSLYEVSEKQETERVLHDDECPLLIQLEWgPQGTE 80

                  ....*..
gi 1958661224 176 SRFIFRK 182
Cdd:cd17043    81 FRFVLKR 87

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 1958661224 429 HRTQPWFHGRIS--REESQRLIGQ-QGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCL-YFSMDDGQtr 504
Cdd:cd10341     1 HFTEPWFHGKLGdgRDEAEKLLLEyCEGGDGTFLVRESETFVGDYTLSFWRNGKVQHCRIRSRQENGEKkYYLTDNLV-- 78

                          90
                  ....*....|....*
gi 1958661224 505 FTDLLQLVEFHQLNR 519
Cdd:cd10341    79 FDSLYELIDYYRQNP 93

Src homology 2 (SH2) domain found in SH2-containing inositol-5'-phosphatase (SHIP) and SLAM-associated protein (SAP); The SH2-containing inositol-5'-phosphatase, SHIP (also called SHIP1/SHIP1a), is a hematopoietic-restricted phosphatidylinositide phosphatase that translocates to the plasma membrane after extracellular stimulation and hydrolyzes the phosphatidylinositol-3-kinase (PI3K)-generated second messenger PI-3,4,5-P3 (PIP3) to PI-3,4-P2. As a result, SHIP dampens down PIP3 mediated signaling and represses the proliferation, differentiation, survival, activation, and migration of hematopoietic cells. PIP3 recruits lipid-binding pleckstrin homology(PH) domain-containing proteins to the inner wall of the plasma membrane and activates them. PH domain-containing downstream effectors include the survival/proliferation enhancing serine/threonine kinase, Akt (protein kinase B), the tyrosine kinase, Btk, the regulator of protein translation, S6K, and the Rac and cdc42 guanine nucleotide exchange factor, Vav. SHIP is believed to act as a tumor suppressor during leukemogenesis and lymphomagenesis, and may play a role in activating the immune system to combat cancer. SHIP contains an N-terminal SH2 domain, a centrally located phosphatase domain that specifically hydrolyzes the 5'-phosphate from PIP3, PI-4,5-P2 and inositol-1,3,4,5- tetrakisphosphate (IP4), a C2 domain, that is an allosteric activating site when bound by SHIP's enzymatic product, PI-3,4-P2; 2 NPXY motifs that bind proteins with a phosphotyrosine binding (Shc, Dok 1, Dok 2) or an SH2 (p85a, SHIP2) domain; and a proline-rich domain consisting of four PxxP motifs that bind a subset of SH3-containing proteins including Grb2, Src, Lyn, Hck, Abl, PLCg1, and PIAS1. The SH2 domain of SHIP binds to the tyrosine phosphorylated forms of Shc, SHP-2, Doks, Gabs, CD150, platelet-endothelial cell adhesion molecule, Cas, c-Cbl, immunoreceptor tyrosine-based inhibitory motifs (ITIMs), and immunoreceptor tyrosine-based activation motifs (ITAMs). The X-linked lymphoproliferative syndrome (XLP) gene encodes SAP (also called SH2D1A/DSHP) a protein that consists of a 5 residue N-terminus, a single SH2 domain, and a short 25 residue C-terminal tail. XLP is characterized by an extreme sensitivity to Epstein-Barr virus. Both T and natural killer (NK) cell dysfunctions have been seen in XLP patients. SAP binds the cytoplasmic tail of Signaling lymphocytic activation molecule (SLAM), 2B4, Ly-9, and CD84. SAP is believed to function as a signaling inhibitor, by blocking or regulating binding of other signaling proteins. SAP and the SAP-like protein EAT-2 recognize the sequence motif TIpYXX(V/I), which is found in the cytoplasmic domains of a restricted number of T, B, and NK cell surface receptors and are proposed to be natural inhibitors or regulators of the physiological role of a small family of receptors on the surface of these cells. 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 1958661224 432 QPWFHGRISREESQRLIGQQGlVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPsEDEGCLYFSMDDG--QTRFTDLL 509
Cdd:cd10343     3 PPWYHGNITRSKAEELLSKAG-KDGSFLVRDSESVSGAYALCVLYQNCVHTYRILP-NAEDKLSVQASEGvpVRFFTTLP 80

                          90
                  ....*....|....*...
gi 1958661224 510 QLVEFH-QLNRGILPCLL 526
Cdd:cd10343    81 ELIEFYqKENMGLVTHLL 98

Src homology 2 (SH2) domain found in Nck; 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 1958661224 432 QPWFHGRISREESQRLIGQQGlVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCLyfsmddGQTRFTDLLQL 511
Cdd:cd10408     1 NPWYYGKVTRHQAEMALNERG-NEGDFLIRDSESSPNDFSVSLKAQGKNKHFKVQLKECVYCI------GQRKFSSMEEL 73

                  ....*
gi 1958661224 512 VEFHQ 516
Cdd:cd10408    74 VEHYK 78

Src homology 2 (SH2) domain found in Nck; 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 1958661224 434 WFHGRISREESQRLIGQQGlVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSEDEGCLyfsmddGQTRFTDLLQLVE 513
Cdd:cd10409     3 WYYGNVTRHQAECALNERG-VEGDFLIRDSESSPSDFSVSLKAVGKNKHFKVQLVDNVYCI------GQRRFNSMDELVE 75

                  ...
gi 1958661224 514 FHQ 516
Cdd:cd10409    76 HYK 78

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 1958661224 431 TQPWFHGRISREESQRLIGQQGLVDGVFLVRESQRNPQGFVLSLCHLQKVKHYLILPSeDEGCLYFsmdDGQTRFTDLLQ 510
Cdd:cd10358     1 SEPWFFGCISRSEAVRRLQAEGNATGAFLIRVSEKPSADYVLSVRDTQAVRHYKIWRR-AGGRLHL---NEAVSFLSLPE 76

                          90       100
                  ....*....|....*....|
gi 1958661224 511 LVEFHQ---LNRGI---LPC 524
Cdd:cd10358    77 LVNYHRaqsLSHGLrlaAPC 96