Guanylate kinase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 202 YTRPVIILGPM---KDRINDDLISEFPDKFGSCVPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLY 278
Cdd:pfam00625   1 SRRPVVLSGPSgvgKSHIKKALLSEYPDKFGYSVPHTTRPPRKGEVDGKDYYFV-SKEEMERDISANEFLEYAQFSGNMY 79

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 279 GTSVQSVRFVAERGKHCILDVSGNAIKRLQVAQLYPIAIFIKPRSLEPLMEMNKRLTEEQAKKTYDRAIKLEQEFGEY-F 357
Cdd:pfam00625  80 GTSVETIEQIHEQGKIVILDVDPQGVKQLRKAELSPISVFIKPPSLKVLQRRLKGRGKEQEEKINKRMAAAEQEFQHYeF 159

                         170       180
                  ....*....|....*....|...
gi 1034572264 358 TAIVQGDTLEDIYNQCKLVIEEQ 380
Cdd:pfam00625 160 DVIIVNDDLEEAYKKLKEALEAE 182

Guanylate kinase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 202 YTRPVIILGPM---KDRINDDLISEFPDKFGSCVPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLY 278
Cdd:pfam00625   1 SRRPVVLSGPSgvgKSHIKKALLSEYPDKFGYSVPHTTRPPRKGEVDGKDYYFV-SKEEMERDISANEFLEYAQFSGNMY 79

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 279 GTSVQSVRFVAERGKHCILDVSGNAIKRLQVAQLYPIAIFIKPRSLEPLMEMNKRLTEEQAKKTYDRAIKLEQEFGEY-F 357
Cdd:pfam00625  80 GTSVETIEQIHEQGKIVILDVDPQGVKQLRKAELSPISVFIKPPSLKVLQRRLKGRGKEQEEKINKRMAAAEQEFQHYeF 159

                         170       180
                  ....*....|....*....|...
gi 1034572264 358 TAIVQGDTLEDIYNQCKLVIEEQ 380
Cdd:pfam00625 160 DVIIVNDDLEEAYKKLKEALEAE 182

Src Homology 3 domain of Disks Large homolog 2; DLG2, also called postsynaptic density-93 (PSD93) or Channel-associated protein of synapse-110 (chapsyn 110), is a scaffolding protein that clusters at synapses and plays an important role in synaptic development and plasticity. The DLG2 delta isoform binds inwardly rectifying potassium Kir2 channels, which determine resting membrane potential in neurons. It regulates the spatial and temporal distribution of Kir2 channels within neuronal membranes. DLG2 is a member of the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. DLG2 contains three PDZ domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1034572264  43 NQKRSLYVRAMFDYDKSKDSGLPSQGLSFKYGDILHVINASDDEWWQARRVMLEGDSEEMGVIPSKRRVERKER 116
Cdd:cd12032     1 NQKRSLYVRAMFDYEKSKDSGLPSQGLSFRYGDILHVINASDDEWWQARRVTPDGDSEEMGVIPSKRRVERKER 74

Guanosine monophosphate kinase (GMPK, EC 2.7.4.8), also known as guanylate kinase (GKase), catalyzes the reversible phosphoryl transfer from adenosine triphosphate (ATP) to guanosine monophosphate (GMP) to yield adenosine diphosphate (ADP) and guanosine diphosphate (GDP). It plays an essential role in the biosynthesis of guanosine triphosphate (GTP). This enzyme is also important for the activation of some antiviral and anticancer agents, such as acyclovir, ganciclovir, carbovir, and thiopurines.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 205 PVIILGPM---KDRINDDLISEFPDKFGSCVPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLYGTS 281
Cdd:cd00071     1 LIVLSGPSgvgKSTLLKRLLEEFDPNFGFSVSHTTRKPRPGEVDGVDYHFV-SKEEFERLIENGEFLEWAEFHGNYYGTS 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 1034572264 282 VQSVRFVAERGKHCILDVSGNAIKRLQVAQLYPIAIFIKP 321
Cdd:cd00071    80 KAAVEEALAEGKIVILEIDVQGARQVKKSYPDAVSIFILP 119

Guanylate kinase [Nucleotide transport and metabolism];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 232 VPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLYGTSVQSVRFVAERGKHCIL--DVSGnAikrLQV 309
Cdd:COG0194    33 VSATTRPPRPGEVDGVDYHFV-SREEFERMIENGEFLEWAEVHGNYYGTPKAEVEEALAAGKDVLLeiDVQG-A---RQV 107

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1034572264 310 AQLYP--IAIFIKPRSLEplmEMNKRLT-------EEQAK--KTYDRAIKLEQEF 353
Cdd:COG0194   108 KKKFPdaVSIFILPPSLE---ELERRLRgrgtdseEVIERrlAKAREELAHADEF 159

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

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*..
gi 1034572264  51 RAMFDYDKSKDSGLpsqglSFKYGDILHVINASDDEWWQARRvmlegDSEEMGVIPS 107
Cdd:pfam00018   1 VALYDYTAQEPDEL-----SFKKGDIIIVLEKSEDGWWKGRN-----KGGKEGLIPS 47

Guanylate kinase;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 202 YTRPVIILGPM---KDRINDDLISEFPDKFGSCVPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLY 278
Cdd:pfam00625   1 SRRPVVLSGPSgvgKSHIKKALLSEYPDKFGYSVPHTTRPPRKGEVDGKDYYFV-SKEEMERDISANEFLEYAQFSGNMY 79

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 279 GTSVQSVRFVAERGKHCILDVSGNAIKRLQVAQLYPIAIFIKPRSLEPLMEMNKRLTEEQAKKTYDRAIKLEQEFGEY-F 357
Cdd:pfam00625  80 GTSVETIEQIHEQGKIVILDVDPQGVKQLRKAELSPISVFIKPPSLKVLQRRLKGRGKEQEEKINKRMAAAEQEFQHYeF 159

                         170       180
                  ....*....|....*....|...
gi 1034572264 358 TAIVQGDTLEDIYNQCKLVIEEQ 380
Cdd:pfam00625 160 DVIIVNDDLEEAYKKLKEALEAE 182

Src Homology 3 domain of Disks Large homolog 2; DLG2, also called postsynaptic density-93 (PSD93) or Channel-associated protein of synapse-110 (chapsyn 110), is a scaffolding protein that clusters at synapses and plays an important role in synaptic development and plasticity. The DLG2 delta isoform binds inwardly rectifying potassium Kir2 channels, which determine resting membrane potential in neurons. It regulates the spatial and temporal distribution of Kir2 channels within neuronal membranes. DLG2 is a member of the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. DLG2 contains three PDZ domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60        70
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1034572264  43 NQKRSLYVRAMFDYDKSKDSGLPSQGLSFKYGDILHVINASDDEWWQARRVMLEGDSEEMGVIPSKRRVERKER 116
Cdd:cd12032     1 NQKRSLYVRAMFDYEKSKDSGLPSQGLSFRYGDILHVINASDDEWWQARRVTPDGDSEEMGVIPSKRRVERKER 74

Src Homology 3 domain of Disks Large homolog 1; DLG1, also called synapse-associated protein 97 (SAP97), is a scaffolding protein that clusters at synapses and plays an important role in synaptic development and plasticity. DLG1 plays roles in regulating cell polarity, proliferation, migration, and cycle progression. It interacts with AMPA-type glutamate receptors and is critical in their maturation and delivery to synapses. It also interacts with PKCalpha and promotes wound healing. DLG1 is a member of the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. DLG1 contains three PDZ domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1034572264  46 RSLYVRAMFDYDKSKDSGLPSQGLSFKYGDILHVINASDDEWWQARRVMLEGDSEEMGVIPSKRRVE 112
Cdd:cd12031     1 RSLYVRALFDYDKTKDSGLPSQGLNFKFGDILHVVNASDDEWWQARQVTADGESEEIGVIPSKRRVE 67

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 1034572264  46 RSLYVRAMFDYDKSKDSGLPSQGLSFKYGDILHVINASDDEWWQARRVMLEGDSEEMGVIPSKRRVE 112
Cdd:cd12029     1 RSLYVRALFDYDRTRDSCLPSQGLSFSYGDILHVINASDDEWWQARLVTPHGESEQIGVIPSKKRVE 67

Guanosine monophosphate kinase (GMPK, EC 2.7.4.8), also known as guanylate kinase (GKase), catalyzes the reversible phosphoryl transfer from adenosine triphosphate (ATP) to guanosine monophosphate (GMP) to yield adenosine diphosphate (ADP) and guanosine diphosphate (GDP). It plays an essential role in the biosynthesis of guanosine triphosphate (GTP). This enzyme is also important for the activation of some antiviral and anticancer agents, such as acyclovir, ganciclovir, carbovir, and thiopurines.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 205 PVIILGPM---KDRINDDLISEFPDKFGSCVPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLYGTS 281
Cdd:cd00071     1 LIVLSGPSgvgKSTLLKRLLEEFDPNFGFSVSHTTRKPRPGEVDGVDYHFV-SKEEFERLIENGEFLEWAEFHGNYYGTS 79

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|
gi 1034572264 282 VQSVRFVAERGKHCILDVSGNAIKRLQVAQLYPIAIFIKP 321
Cdd:cd00071    80 KAAVEEALAEGKIVILEIDVQGARQVKKSYPDAVSIFILP 119

Guanylate kinase [Nucleotide transport and metabolism];

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 232 VPHTTRPKRDYEVDGRDYHFViSREQMEKDIQEHKFIEAGQYNDNLYGTSVQSVRFVAERGKHCIL--DVSGnAikrLQV 309
Cdd:COG0194    33 VSATTRPPRPGEVDGVDYHFV-SREEFERMIENGEFLEWAEVHGNYYGTPKAEVEEALAAGKDVLLeiDVQG-A---RQV 107

                          90       100       110       120       130
                  ....*....|....*....|....*....|....*....|....*....|....*
gi 1034572264 310 AQLYP--IAIFIKPRSLEplmEMNKRLT-------EEQAK--KTYDRAIKLEQEF 353
Cdd:COG0194   108 KKKFPdaVSIFILPPSLE---ELERRLRgrgtdseEVIERrlAKAREELAHADEF 159

Src Homology 3 domain of Membrane Protein, Palmitoylated (or MAGUK p55 subfamily member) proteins; The MPP/p55 subfamily of MAGUK (membrane-associated guanylate kinase) proteins includes at least eight vertebrate members (MPP1-7 and CASK), four Drosophila proteins (Stardust, Varicose, CASK and Skiff), and other similar proteins; they all contain one each of the core of three domains characteristic of MAGUK proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, most members except for MPP1 contain N-terminal L27 domains and some also contain a Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. CASK has an additional calmodulin-dependent kinase (CaMK)-like domain at the N-terminus. Members of this subfamily are scaffolding proteins that play important roles in regulating and establishing cell polarity, cell adhesion, and synaptic targeting and transmission, among others. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1034572264  49 YVRAMFDYDKSKDSGLPSQ--GLSFKYGDILHVINASDDEWWQARRVmlEGDSEEMGVIPSK 108
Cdd:cd11862     1 FVRALFDYDPEEDPLIPCKeaGLSFKKGDILQIVNQDDPNWWQARKV--GDPNGRAGLIPSQ 60

Src Homology 3 domain of Membrane Protein, Palmitoylated 5 (or MAGUK p55 subfamily member 5); MPP5, also called PALS1 (Protein associated with Lin7) or Nagie oko protein in zebrafish or Stardust in Drosophila, is a scaffolding protein which associates with Crumbs homolog 1 (CRB1), CRB2, or CRB3 through its PDZ domain and with PALS1-associated tight junction protein (PATJ) or multi-PDZ domain protein 1 (MUPP1) through its L27 domain. The resulting tri-protein complexes are core proteins of the Crumb complex, which localizes at tight junctions or subapical regions, and is involved in the maintenance of apical-basal polarity in epithelial cells and the morphogenesis and function of photoreceptor cells. MPP5 is critical for the proper stratification of the retina and is also expressed in T lymphocytes where it is important for TCR-mediated activation of NFkB. Drosophila Stardust exists in several isoforms, some of which show opposing functions in photoreceptor cells, which suggests that the relative ratio of different Crumbs complexes regulates photoreceptor homeostasis. MPP5 contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1034572264  49 YVRAMFDYDKSKDSGLPSQ--GLSFKYGDILHVINASDDEWWQARRVMLEGDSEEMGVIPSK 108
Cdd:cd12036     1 HVRAHFDYDPEDDPYIPCRelGLSFQKGDILHVISQEDPNWWQAYREGEEDNQSLAGLIPSK 62

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 1034572264  49 YVRAMFDYDKSKDSGLPSQ--GLSFKYGDILHVINASDDEWWQARrvmLEGDSE-EMGVIPSK 108
Cdd:cd12033     1 FIKALFDYNPNEDKAIPCKeaGLSFKKGDILQIMSQDDATWWQAK---HEGDANpRAGLIPSK 60

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

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 1034572264  49 YVRAMFDYDKSKDSGLPSQ--GLSFKYGDILHVINASDDEWWQARRVmleGDSE-EMGVIPSKR 109
Cdd:cd12039     1 FMRALFDYNPYEDRAIPCQeaGLPFKRRDILEVVSQDDPTWWQAKRV---GDTNlRAGLIPSKQ 61

Src Homology 3 domain of Membrane Protein, Palmitoylated 2 (or MAGUK p55 subfamily member 2); MPP2 is a scaffolding protein that interacts with the non-receptor tyrosine kinase c-Src in epithelial cells to negatively regulate its activity and morphological function. It is one of seven vertebrate homologs of the Drosophila Stardust protein, which is required in establishing cell polarity, and it contains two L27 domains followed by the core of three domains characteristic of MAGUK (membrane-associated guanylate kinase) proteins: PDZ, SH3, and guanylate kinase (GuK). In addition, it also contains the Hook (Protein 4.1 Binding) motif in between the SH3 and GuK domains. The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 1034572264  49 YVRAMFDYDKSKDSGLPSQ--GLSFKYGDILHVINASDDEWWQArrVMLEGDSEemGVIPSK 108
Cdd:cd12037     1 FVKCHFDYDPSSDSLIPCKeaGLKFRAGDLLQIVNQEDPNWWQA--CHVEGGSA--GLIPSQ 58

Src homology 3 domains; Src homology 3 (SH3) domains bind to target proteins through sequences containing proline and hydrophobic amino acids. Pro-containing polypeptides may bind to SH3 domains in 2 different binding orientations.

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*....
gi 1034572264   49 YVRAMFDYDKSKDsglpsQGLSFKYGDILHVINASDDEWWQARRvmlegDSEEMGVIPS 107
Cdd:smart00326   4 QVRALYDYTAQDP-----DELSFKKGDIITVLEKSDDGWWKGRL-----GRGKEGLFPS 52

Src Homology 3 domain superfamily; Src Homology 3 (SH3) domains are protein interaction domains that bind proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. Thus, they are referred to as proline-recognition domains (PRDs). SH3 domains are less selective and show more diverse specificity compared to other PRDs. They have been shown to bind peptide sequences that lack the PxxP motif; examples include the PxxDY motif of Eps8 and the RKxxYxxY sequence in SKAP55. SH3 domain containing proteins play versatile and diverse roles in the cell, including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies, among others. Many members of this superfamily are adaptor proteins that associate with a number of protein partners, facilitating complex formation and signal transduction.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*....
gi 1034572264  49 YVRAMFDYDKSKDsglpsQGLSFKYGDILHVINASDDEWWQARRvmlegDSEEMGVIPS 107
Cdd:cd00174     1 YARALYDYEAQDD-----DELSFKKGDIITVLEKDDDGWWEGEL-----NGGREGLFPA 49

Src homology 3 domain of Src kinase-like Protein Tyrosine Kinases; Src subfamily members include Src, Lck, Hck, Blk, Lyn, Fgr, Fyn, Yrk, Yes, and Brk. Src (or c-Src) proteins are cytoplasmic (or non-receptor) PTKs which are anchored to the plasma membrane. They contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). However, Brk lacks the N-terminal myristoylation sites. Src proteins are involved in signaling pathways that regulate cytokine and growth factor responses, cytoskeleton dynamics, cell proliferation, survival, and differentiation. They were identified as the first proto-oncogene products, and they regulate cell adhesion, invasion, and motility in cancer cells, and tumor vasculature, contributing to cancer progression and metastasis. Src kinases are overexpressed in a variety of human cancers, making them attractive targets for therapy. They are also implicated in acute inflammatory responses and osteoclast function. Src, Fyn, Yes, and Yrk are widely expressed, while Blk, Lck, Hck, Fgr, Lyn, and Brk show a limited expression pattern. This subfamily also includes Drosophila Src42A, Src oncogene at 42A (also known as Dsrc41) which accumulates at sites of cell-cell or cell-matrix adhesion, and participates in Drosphila development and wound healing. It has been shown to promote tube elongation in the tracheal system, is essential for proper cell-cell matching during dorsal closure, and regulates cell-cell contacts in developing Drosophila eyes. The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|....*...
gi 1034572264  50 VRAMFDYDKSKDSGLpsqglSFKYGDILHVINASDDEWWQARRVmlegDSEEMGVIPS 107
Cdd:cd11845     2 YVALYDYEARTDDDL-----SFKKGDRLQILDDSDGDWWLARHL----STGKEGYIPS 50

guanylate kinase; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 208 ILGPMKDRINDDLISEFPDKFGScVPHTTRPKRDYEVDGRDYHFvISREQMEKDIQEHKFIEAGQYNDNLYGTSVQSVRF 287
Cdd:PRK14737   12 VAGGGKSTIIQALLEEHPDFLFS-ISCTTRAPRPGDEEGKTYFF-LTIEEFKKGIADGEFLEWAEVHDNYYGTPKAFIED 89

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1034572264 288 VAERGKHCILDVSGNAIKrlQVAQLYP---IAIFIKPRSLEPLME-MNKRLTEEQA---KKTYDRAIKLEQEfgEYFTAI 360
Cdd:PRK14737   90 AFKEGRSAIMDIDVQGAK--IIKEKFPeriVTIFIEPPSEEEWEErLIHRGTDSEEsieKRIENGIIELDEA--NEFDYK 165

                         170
                  ....*....|....*..
gi 1034572264 361 VQGDTLEDIYNQCKLVI 377
Cdd:PRK14737  166 IINDDLEDAIADLEAII 182

N-terminal Src Homology 3 domain of Ct10 Regulator of Kinase adaptor proteins; CRK adaptor proteins consists of SH2 and SH3 domains, which bind tyrosine-phosphorylated peptides and proline-rich motifs, respectively. They function downstream of protein tyrosine kinases in many signaling pathways started by various extracellular signals, including growth and differentiation factors. Cellular CRK (c-CRK) contains a single SH2 domain, followed by N-terminal and C-terminal SH3 domains. It is involved in the regulation of many cellular processes including cell growth, motility, adhesion, and apoptosis. CRK has been implicated in the malignancy of various human cancers. The N-terminal SH3 domain of CRK binds a number of target proteins including DOCK180, C3G, SOS, and cABL. The CRK family includes two alternatively spliced protein forms, CRKI and CRKII, that are expressed by the CRK gene, and the CRK-like (CRKL) protein, which is expressed by a distinct gene (CRKL). SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  49 YVRAMFDYDKSKDSGLPsqglsFKYGDILHVINASDDEWWQARrvmlegDSE-EMGVIP 106
Cdd:cd11758     2 YVRALFDFPGNDDEDLP-----FKKGEILTVIRKPEEQWWNAR------NSEgKTGMIP 49

Src Homology 3 domain of Voltage-dependent L-type calcium channel subunit beta; Voltage-dependent calcium channels (Ca(V)s) are multi-protein complexes that regulate the entry of calcium into cells. They impact muscle contraction, neuronal migration, hormone and neurotransmitter release, and the activation of calcium-dependent signaling pathways. They are composed of four subunits: alpha1, alpha2delta, beta, and gamma. The beta subunit is a soluble and intracellular protein that interacts with the transmembrane alpha1 subunit. It facilitates the trafficking and proper localization of the alpha1 subunit to the cellular plasma membrane. Vertebrates contain four different beta subunits from distinct genes (beta1-4); each exists as multiple splice variants. All are expressed in the brain while other tissues show more specific expression patterns. The beta subunits show similarity to MAGUK (membrane-associated guanylate kinase) proteins in that they contain SH3 and inactive guanylate kinase (GuK) domains; however, they do not appear to contain a PDZ domain. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  50 VRAMFDYDKSKDSGLPSQG--LSFKYGDILHVINASDDEWWQARRVmleGDSEEMGVIPSKRR 110
Cdd:cd11863     3 VRTNVGYDGSLDDDSPVPGyaVSFEAKDFLHIKEKYNNDWWIGRLV---KEGCDIGFIPSPAK 62

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

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gi 1034572264  49 YVRAMFDYDKSkdsglPSQGLSFKYGDILHVINASDDEWWQARRvmlegdSEEMGVIPSKRRVE 112
Cdd:pfam07653   1 YGRVIFDYVGT-----DKNGLTLKKGDVVKVLGKDNDGWWEGET------GGRVGLVPSTAVEE 53

First Src Homology 3 domain of the fungal endocytic adaptor protein Sla1p; Sla1p facilitates endocytosis by playing a role as an adaptor protein in coupling components of the actin cytoskeleton to the endocytic machinery. It interacts with Abp1p, Las17p and Pan1p, which are activator proteins of actin-related protein 2/3 (Arp2/3). Sla1p contains multiple domains including three SH3 domains, a SAM (sterile alpha motif) domain, and a Sla1 homology domain 1 (SHD1), which binds to the NPFXD motif that is found in many integral membrane proteins such as the Golgi-localized Arf-binding protein Lsb5p and the P4-ATPases, Drs2p and Dnf1p. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  50 VRAMFDYDkskdsglpSQG---LSFKYGDILHVINASDDEWWQAR-RVMLEGDSEEMGVIPS 107
Cdd:cd11773     2 YKALYDYE--------PQTedeLTIQEDDILYLLEKSDDDWWKVKlKVNSSDDDEPVGLVPA 55

Src homology 3 domain of Yes Protein Tyrosine Kinase; Yes (or c-Yes) is a member of the Src subfamily of proteins, which are cytoplasmic (or non-receptor) PTKs. c-Yes kinase is the cellular homolog of the oncogenic protein (v-Yes) encoded by the Yamaguchi 73 and Esh sarcoma viruses. It displays functional overlap with other Src subfamily members, particularly Src. It also shows some unique functions such as binding to occludins, transmembrane proteins that regulate extracellular interactions in tight junctions. Yes also associates with a number of proteins in different cell types that Src does not interact with, like JAK2 and gp130 in pre-adipocytes, and Pyk2 in treated pulmonary vein endothelial cells. Although the biological function of Yes remains unclear, it appears to have a role in regulating cell-cell interactions and vesicle trafficking in polarized cells. Src kinases contain an N-terminal SH4 domain with a myristoylation site, followed by SH3 and SH2 domains, a tyr kinase domain, and a regulatory C-terminal region containing a conserved tyr. They are activated by autophosphorylation at the tyr kinase domain, but are negatively regulated by phosphorylation at the C-terminal tyr by Csk (C-terminal Src Kinase). The SH3 domain of Src kinases contributes to substrate recruitment by binding adaptor proteins/substrates, and regulation of kinase activity through an intramolecular interaction. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  52 AMFDYDKSKdsglpSQGLSFKYGDILHVINASDDEWWQARRVmlegDSEEMGVIPS 107
Cdd:cd12007     5 ALYDYEART-----TEDLSFKKGERFQIINNTEGDWWEARSI----ATGKNGYIPS 51

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

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gi 1034572264  50 VRAMFDYDKSKDSGLpsqglSFKYGDILHVINASDDEWWQarrvmleGDSEE-MGVIPS 107
Cdd:cd11964     3 VRAIYDFEAAEDNEL-----TFKAGDIITILDDSDPNWWK-------GETPQgTGLFPS 49

Src homology 3 domain of Signal Transducing Adaptor Molecules; STAMs were discovered as proteins that are highly phosphorylated following cytokine and growth factor stimulation. They function in cytokine signaling and surface receptor degradation, as well as regulate Golgi morphology. They associate with many proteins including Jak2 and Jak3 tyrosine kinases, Hrs, AMSH, and UBPY. STAM adaptor proteins contain VHS (Vps27, Hrs, STAM homology), ubiquitin interacting (UIM), and SH3 domains. There are two vertebrate STAMs, STAM1 and STAM2, which may be functionally redundant; vertebrate STAMs contain ITAM motifs. They are part of the endosomal sorting complex required for transport (ESCRT-0). STAM2 deficiency in mice did not cause any obvious abnormality, while STAM1 deficiency resulted in growth retardation. Loss of both STAM1 and STAM2 in mice proved lethal, indicating that STAMs are important for embryonic development. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  50 VRAMFDYDKSKDSGLpsqglSFKYGDILHVINASDDEWWQ 89
Cdd:cd11820     3 VRALYDFEAAEDNEL-----TFKAGEIITVLDDSDPNWWK 37

Src homology 3 domain of the Tight junction protein, Zonula occludens protein 3; ZO-3 is a scaffolding protein that associates with other ZO proteins and other proteins of the tight junction, zonula adherens, and gap junctions. ZO proteins play roles in regulating cytoskeletal dynamics at these cell junctions. ZO-3 is critical for epidermal barrier function. It regulates cyclin D1-dependent cell proliferation. It is considered a member of the MAGUK (membrane-associated guanylate kinase) protein family, which is characterized by the presence of a core of three domains: PDZ, SH3, and guanylate kinase (GuK). The GuK domain in MAGUK proteins is enzymatically inactive; instead, the domain mediates protein-protein interactions and associates intramolecularly with the SH3 domain. The C-terminal region of ZO-3 is the smallest of the three ZO proteins. The SH3 domain of the related protein ZO-1 has been shown to bind ZONAB, ZAK, afadin, and Galpha12. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  47 SLYVRAMFDYDKSkdsglPSQGLSFKYGDILHVINA---SDDEWWQARRVMLEGDSEEMGVIPSKRRVE 112
Cdd:cd12028     2 SFYIRTHFDYEPD-----PPSGLSFTRGEVFHVLDTmhrGKLGSWLAVRMGRDLREMEKGIIPNQSRAE 65

Src Homology 3 domain of Nephrocystin (or Nephrocystin-1); Nephrocystin contains an SH3 domain involved in signaling pathways that regulate cell adhesion and cytoskeletal organization. It is a protein that in humans is associated with juvenile nephronophthisis, an inherited kidney disease characterized by renal fibrosis that lead to chronic renal failure in children. It is localized in cell-cell junctions in renal duct cells, and is known to interact with Ack1, an activated Cdc42-associated kinase. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  69 LSFKYGDILHVINASDDEWWQARRVmlEGDSeemGVIPS 107
Cdd:cd11770    16 LSFKKGEVLRIISKRADGWWLAENS--KGNR---GLVPK 49

Src Homology 3 domain of Sdc25/Cdc25 guanine nucleotide exchange factors; This subfamily is composed of the Saccharomyces cerevisiae guanine nucleotide exchange factors (GEFs) Sdc25 and Cdc25, and similar proteins. These GEFs regulate Ras by stimulating the GDP/GTP exchange on Ras. Cdc25 is involved in the Ras/PKA pathway that plays an important role in the regulation of metabolism, stress responses, and proliferation, depending on available nutrients and conditions. Proteins in this subfamily contain an N-terminal SH3 domain as well as REM (Ras exchanger motif) and RasGEF domains at the C-terminus. SH3 domains bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs; they play a role in the regulation of enzymes by intramolecular interactions, changing the subcellular localization of signal pathway components and mediate multiprotein complex assemblies.

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gi 1034572264  49 YVRAMFDYDkskdSGLPSQgLSFKYGDILHVINASDDEWW 88
Cdd:cd11883     1 VVVALYDFT----PKSKNQ-LSFKAGDIIYVLNKDPSGWW 35

Src homology 3 domain of ARHGEF9-like Rho guanine nucleotide exchange factors; Members of this family contain a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. They include the Rho guanine nucleotide exchange factors ARHGEF9, ASEF (also called ARHGEF4), ASEF2, and similar proteins. GEFs activate small GTPases by exchanging bound GDP for free GTP. ARHGEF9 specifically activates Cdc42, while both ASEF and ASEF2 can activate Rac1 and Cdc42. ARHGEF9 is highly expressed in the brain and it interacts with gephyrin, a postsynaptic protein associated with GABA and glycine receptors. ASEF plays a role in angiogenesis and cell migration. ASEF2 is important in cell migration and adhesion dynamics. ASEF exists in an autoinhibited form and is activated upon binding of the tumor suppressor APC (adenomatous polyposis coli), leading to the activation of Rac1 or Cdc42. In its autoinhibited form, the SH3 domain of ASEF forms an extensive interface with the DH and PH domains, blocking the Rac binding site. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  49 YVRAMFDYdKSKDSglpsQGLSFKYGDILHVINASDDEWWQARRVMLEG 97
Cdd:cd11828     1 LAEALWDH-VTMDP----EELGFKAGDVIEVLDMSDKDWWWGSIRDEEG 44

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

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gi 1034572264  49 YVRAMFDYDKSKDsglpsQGLSFKYGDILHVINAS----DDEWWQARrvmLEGdseEMGVIPS 107
Cdd:cd11762     1 LVRALYDYEAQSD-----EELSFPEGAIIRILRKDdngvDDGWWEGE---FNG---RVGVFPS 52

Src homology 3 domain of APC-Stimulated guanine nucleotide Exchange Factor 2; ASEF2, also called Spermatogenesis-associated protein 13 (SPATA13), is a GEF that localizes with actin at the leading edge of cells and is important in cell migration and adhesion dynamics. GEFs activate small GTPases by exchanging bound GDP for free GTP. ASEF2 can activate both Rac 1 and Cdc42, but only Rac1 activation is necessary for increased cell migration and adhesion turnover. Together with APC (adenomatous polyposis coli) and Neurabin2, a scaffold protein that binds F-actin, it is involved in regulating HGF-induced cell migration. ASEF2 contains a SH3 domain followed by RhoGEF (also called Dbl-homologous or DH) and Pleckstrin Homology (PH) domains. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  48 LYVRAMFDYDKSKDsglpsQGLSFKYGDILHVINASDDEWWQAR 91
Cdd:cd11974     1 VYAEALWDHVTMDD-----QELAFKAGDVIRVLEASNKDWWWGR 39

Src Homology 3 domain of C-terminal Src kinase; CSK is a cytoplasmic (or nonreceptor) tyr kinase containing the Src homology domains, SH3 and SH2, N-terminal to the catalytic tyr kinase domain. They negatively regulate the activity of Src kinases that are anchored to the plasma membrane. To inhibit Src kinases, CSK is translocated to the membrane via binding to specific transmembrane proteins, G-proteins, or adaptor proteins near the membrane. CSK catalyzes the tyr phosphorylation of the regulatory C-terminal tail of Src kinases, resulting in their inactivation. It is expressed in a wide variety of tissues and plays a role, as a regulator of Src, in cell proliferation, survival, and differentiation, and consequently, in cancer development and progression. In addition, CSK also shows Src-independent functions. It is a critical component in G-protein signaling, and plays a role in cytoskeletal reorganization and cell migration. SH3 domains are protein interaction domains that bind to proline-rich ligands with moderate affinity and selectivity, preferentially to PxxP motifs. They play versatile and diverse roles in the cell including the regulation of enzymes, changing the subcellular localization of signaling pathway components, and mediating the formation of multiprotein complex assemblies.

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gi 1034572264  63 GLPSQGLSFKYGDILHVINASDD-EWWQARRVmlegDSEEmGVIP 106
Cdd:cd11769    12 GASEEDLPFKKGDILTIVAVTKDpNWYKAKNK----DGRE-GMIP 51