SNARE motif, subgroup Qa; SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complex mediates membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles. Examples for members of the Qa SNAREs are syntaxin 18, syntaxin 5, syntaxin 16, and syntaxin 1.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 5281026  187 IEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15840   1 IEEREEEIREIESSIGEVNEIFKDLATLVTEQGEQIDNIENNIEEAAANTEEANKELRK 59

Syntaxin N-terminus domain; syntaxins are nervous system-specific proteins implicated in the docking of synaptic vesicles with the presynaptic plasma membrane; they are a family of receptors for intracellular transport vesicles; each target membrane may be identified by a specific member of the syntaxin family; syntaxins contain a moderately well conserved amino-terminal domain, called Habc, whose structure is an antiparallel three-helix bundle; a linker of about 30 amino acids connects this to the carboxy-terminal region, designated H3 (t_SNARE), of the syntaxin cytoplasmic domain; the highly conserved H3 region forms a single, long alpha-helix when it is part of the core SNARE complex and anchors the protein on the cytoplasmic surface of cellular membranes; H3 is not included in defining this domain

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 5281026   24 GSRQDTTQDVASGIFQINTSVSTFHRLVNTLGTPKD-TPELREKLHKTRLYIGQLVKDTSAKLKEASETDHQ------RG 96
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDaDPELKQELESLVQEIKKLAKEIKGKLKELEESNEQnealngSS 81

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 5281026   97 VNQKKKIVDAKLAKDFQAVLKEFQKAQRLAAERETVYAPLVHKpSLPSSYTSSEID 152
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLE-ITGGEATDEELE 136

SNARE motif, subgroup Qa; SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complex mediates membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles. Examples for members of the Qa SNAREs are syntaxin 18, syntaxin 5, syntaxin 16, and syntaxin 1.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 5281026  187 IEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15840   1 IEEREEEIREIESSIGEVNEIFKDLATLVTEQGEQIDNIENNIEEAAANTEEANKELRK 59

Helical region found in SNAREs; All alpha-helical motifs that form twisted and parallel four-helix bundles in target soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor proteins. This motif found in "Q-SNAREs".

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 5281026     182 FNEAVIEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVRH 246
Cdd:smart00397   2 QALAREEERDEELEQLEKSIQELKQIFLDMGTELEEQGEQLDRIEDNVDDADVNLKKANKRLKKA 66

Syntaxin N-terminus domain; syntaxins are nervous system-specific proteins implicated in the docking of synaptic vesicles with the presynaptic plasma membrane; they are a family of receptors for intracellular transport vesicles; each target membrane may be identified by a specific member of the syntaxin family; syntaxins contain a moderately well conserved amino-terminal domain, called Habc, whose structure is an antiparallel three-helix bundle; a linker of about 30 amino acids connects this to the carboxy-terminal region, designated H3 (t_SNARE), of the syntaxin cytoplasmic domain; the highly conserved H3 region forms a single, long alpha-helix when it is part of the core SNARE complex and anchors the protein on the cytoplasmic surface of cellular membranes; H3 is not included in defining this domain

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 5281026   24 GSRQDTTQDVASGIFQINTSVSTFHRLVNTLGTPKD-TPELREKLHKTRLYIGQLVKDTSAKLKEASETDHQ------RG 96
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDaDPELKQELESLVQEIKKLAKEIKGKLKELEESNEQnealngSS 81

                        90       100       110       120       130
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 5281026   97 VNQKKKIVDAKLAKDFQAVLKEFQKAQRLAAERETVYAPLVHKpSLPSSYTSSEID 152
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLE-ITGGEATDEELE 136

SNARE motif, subgroup Qa; SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complex mediates membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles. Examples for members of the Qa SNAREs are syntaxin 18, syntaxin 5, syntaxin 16, and syntaxin 1.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 5281026  187 IEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15840   1 IEEREEEIREIESSIGEVNEIFKDLATLVTEQGEQIDNIENNIEEAAANTEEANKELRK 59

SNARE motif of syntaxin 1 and related proteins; SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complex mediates membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles. This subgroup of the Qa SNAREs includes syntaxin 1, syntaxin 11, syntaxin 19, syntaxin 2, syntaxin 3, syntaxin 4 and related proteins.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 5281026  204 VHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15848  22 LHQMFLDMAVLVESQGELIDNIEYNVEKAKDYVEKGNEELKK 63

SNARE motif of syntaxin 12; Syntaxin 12 (STX12, also known as STX13 and STX14) forms a complex with SNAP25 (Qb/Qc) or SNAP29 (Qb/Qc) and VAMP2 or VAMP3 (R-SNARE) and plays a role in plasma membrane to early endosome transport. Syntaxin 12 is a member of the Qa subgroup of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins, which consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complexes mediate membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 5281026  187 IEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15876   1 IKERETAIQQLEADILDVNQIFKDLAMMIHDQGDMIDSIEANVESAEVHVERASEQLQR 59

Helical region found in SNAREs; All alpha-helical motifs that form twisted and parallel four-helix bundles in target soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptor proteins. This motif found in "Q-SNAREs".

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 5281026     182 FNEAVIEEREQGIQEIQQQIGEVHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVRH 246
Cdd:smart00397   2 QALAREEERDEELEQLEKSIQELKQIFLDMGTELEEQGEQLDRIEDNVDDADVNLKKANKRLKKA 66

SNARE motif of syntaxin 17; Synthaxin 17 (STX17) belongs to the Qa subgroup of SNAREs and interacts with SNAP29 (Qb/Qc) and the lysosomal R-SNARE VAMP8. The complex plays a role in autophagosome-lysosome fusion. Autophagosome transports cytoplasmic materials, including cytoplasmic proteins, glycogen, lipids, organelles, and invading bacteria to the lysosome for degradation. SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins consist of coiled-coil helices (called SNARE motifs) which mediate the interactions between SNARE proteins, and a transmembrane domain. The SNARE complexes mediate membrane fusion, important for trafficking of newly synthesized proteins, recycling of pre-existing proteins and organelle formation. SNARE proteins are classified into four groups, Qa-, Qb-, Qc- and R-SNAREs, depending on whether the residue in the hydrophilic center layer of the four-helical bundle is a glutamine (Q) or arginine (R). Qa-, as well as Qb- and Qc-SNAREs, are localized to target organelle membranes, while R-SNARE is localized to vesicle membranes. They form unique complexes consisting of one member of each subgroup, that mediate fusion between a specific type of vesicles and their target organelle.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|..
gi 5281026  204 VHEIFKDLAVLVHDQGNMIDDIGTHIDNSYAATAQGKSHLVR 245
Cdd:cd15846  21 LHGLFTDFHQLVHDQGEQVDTIEDNVEEALENVQEGTKNLRK 62