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 30583491  39 EEFFHKVRTIRQTIVKLGNKVQELEKQQVTILATPLPEESMKQELQNLRDEIKQLGREIRLQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30583491 119 NTRMRKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 189
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLEITG-GEATDEELEDMLESGNSEIFTSQI 151

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 30583491  39 EEFFHKVRTIRQTIVKLGNKVQELEKQQVTILATPLPEESMKQELQNLRDEIKQLGREIRLQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30583491 119 NTRMRKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 189
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLEITG-GEATDEELEDMLESGNSEIFTSQI 151

SNARE motif of syntaxin 4; Syntaxin-4 forms a complex with SNAP-23 (Qb/Qc) and R-SNAREs VAMP8, VAMP2 and VAMP7 which plays a role in exocytosis of secetory granule. Syntaxin 4 is 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30583491 199 ALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKT 261
Cdd:cd15883   1 ALNEIEARHSEIQKLERSIRELHDMFTYLAMEVEAQGEMIDRIEKNILSSADYVEKAQEHVKT 63

t-SNARE complex subunit, syntaxin [Intracellular trafficking, secretion, and vesicular transport];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491  39 EEFFHKVRTIRQTIVKLGNKVQELEKQQVTILATPLPEESM--KQELQNLRDEIKQLGREIRLQLKAIEPQKeeadenyn 116
Cdd:COG5074  21 VTFMNKILSINKNLSVYEKEINQIDNLHKDLLTEVFEEQSRklRRSLDNFSSQTTDLQRNLKKDIKSAERDG-------- 92

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 117 sVNTRMRKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNAGMVSDEELEQMLDSGQSEVFVSNILKDTQV- 195
Cdd:COG5074  93 -IHLANKQAQAENVRQKFLKLIQDYRIIDSNYREEEKEQARRQYIIAQPEATEDEVEAAINDVNGQQVFSQALLNANRRg 171

                       170       180       190       200       210       220       230       240
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 196 -TRQALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTALENQKKARKKKV 274
Cdd:COG5074 172 eAKTALAEVQARHQEIKKIEKTMAELTQLFNDMEELVIEQQENVDVIDKNVEDAQENVEQGVGHTDKAVKSARAARKKKI 251

                       250       260
                ....*....|....*....|
gi 30583491 275 LI-AICVSITVVLLAVIIGV 293
Cdd:COG5074 252 RCyGICFIIIIVIVVVVFKV 271

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 30583491  39 EEFFHKVRTIRQTIVKLGNKVQELEKQQVTILATPLPEESMKQELQNLRDEIKQLGREIRLQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 30583491 119 NTRMRKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 189
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLEITG-GEATDEELEDMLESGNSEIFTSQI 151

SNARE motif of syntaxin 4; Syntaxin-4 forms a complex with SNAP-23 (Qb/Qc) and R-SNAREs VAMP8, VAMP2 and VAMP7 which plays a role in exocytosis of secetory granule. Syntaxin 4 is 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30583491 199 ALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKT 261
Cdd:cd15883   1 ALNEIEARHSEIQKLERSIRELHDMFTYLAMEVEAQGEMIDRIEKNILSSADYVEKAQEHVKT 63

t-SNARE complex subunit, syntaxin [Intracellular trafficking, secretion, and vesicular transport];

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491  39 EEFFHKVRTIRQTIVKLGNKVQELEKQQVTILATPLPEESM--KQELQNLRDEIKQLGREIRLQLKAIEPQKeeadenyn 116
Cdd:COG5074  21 VTFMNKILSINKNLSVYEKEINQIDNLHKDLLTEVFEEQSRklRRSLDNFSSQTTDLQRNLKKDIKSAERDG-------- 92

                        90       100       110       120       130       140       150       160
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 117 sVNTRMRKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNAGMVSDEELEQMLDSGQSEVFVSNILKDTQV- 195
Cdd:COG5074  93 -IHLANKQAQAENVRQKFLKLIQDYRIIDSNYREEEKEQARRQYIIAQPEATEDEVEAAINDVNGQQVFSQALLNANRRg 171

                       170       180       190       200       210       220       230       240
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 196 -TRQALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTALENQKKARKKKV 274
Cdd:COG5074 172 eAKTALAEVQARHQEIKKIEKTMAELTQLFNDMEELVIEQQENVDVIDKNVEDAQENVEQGVGHTDKAVKSARAARKKKI 251

                       250       260
                ....*....|....*....|
gi 30583491 275 LI-AICVSITVVLLAVIIGV 293
Cdd:COG5074 252 RCyGICFIIIIVIVVVVFKV 271

SNARE motif of syntaxin 2; Syntaxin 2 (STX2), also known as epimorphin (EPM or EPIM), may interact with SNAP-23 (Qb/c) and genetic varioations are associated with type 1 von Willebrand disease (VWD). Syntaxin 2 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 30583491 199 ALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTALENQ 266
Cdd:cd15882   1 ALNEIESRHKDIMKLESSIRELHDMFVDMAMLVETQGEMINNIEKNVHNAVEYVEHAKEETKKAVKYQ 68

SNARE motif of syntaxin 3; Syntaxin 3 (STX3) has been shown to form a complex with VAMP8 (R-SNARE) and SNAP-23 (Qb/c) in mast cells. Mutations have been implicated in human microvillus inclusion disease (MVID), a disorder of the differentiation of intestinal epithelium. Syntaxin 3 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 30583491 199 ALNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTALENQK 267
Cdd:cd15881   1 ALSEIEGRHKDIVRLESSIKELHDMFVDIAMLVENQGEMLDNIELNVMKTVDHVEKARDETKKAVKYQS 69

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 30583491 203 ISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVK 260
Cdd:cd15840   1 IEEREEEIREIESSIGEVNEIFKDLATLVTEQGEQIDNIENNIEEAAANTEEANKELR 58

SNARE motif of Sso1; Saccharomyces cerevisiae SNARE protein Sso1p forms a complex with synaptobrevin homolog Snc1p (R-SNARE) and the SNAP-25 homolog Sec9p (Qb/c) which is involved in exocytosis. Sso1 is 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 30583491 200 LNEISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTA 262
Cdd:cd15849   1 LGEVQARHNEIQRIEQTLTELAQLFNDMATLVEQQDEVIQQIEQNAEEVETDLEKGNVHLEKA 63

SNARE domain; Most if not all vesicular membrane fusion events in eukaryotic cells are believed to be mediated by a conserved fusion machinery, the SNARE [soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (SNAP) receptors] machinery. The SNARE domain is thought to act as a protein-protein interaction module in the assembly of a SNARE protein complex.

                          10        20        30        40        50
                  ....*....|....*....|....*....|....*....|....*....|..
gi 30583491   236 EMINRIEKNILSSADYVERGQEHVKTALENQKKARKKKVLIAICVSITVVLL 287
Cdd:pfam05739   1 EMLDRIDTNVENAQSNVERAQKELKKAVKYQKSNRKLKCIILLILVIILLVV 52

SNARE motif of syntaxin 5; Syntaxin 5 (Syn5) regulates the transport from the ER to the Golgi, as well as the early/recycling endosomes to the trans-Golgi network and participates in the assembly of transitional ER and the Golgi, lipid droplet fusion, and cytokinesis. Syn5 exists in 2 isoforms, long (42 kDa) and short (35 kDa). The short form is localized in the Golgi complex, whereas the long form is additionally found in the endoplasmic reticulum (ER). The syntaxin-5 SNARE complexes, which also contain Bet1 (Qc) and either GS27 (Qb) and Sec22B (R-SNARE) or GS28 (Qb) and Ykt6 (R-SNARE), regulate the early secretory pathway of eukaryotic cells at the level of endoplasmic reticulum (ER) to Golgi transport. The syntaxin-5 SNARE complex, which also contains GS15 (Qc), GS28 (Qb) and Ykt6 (R-SNAREs) is involved in the transport from the trans-Golgi network to the cis-Golgi. Syn5 is 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) that 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.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 203 ISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTALENQKKARK--KKVLIAICV 280
Cdd:cd15844   1 LQSRADAVQNIESTIVELGQIFQQLATMVAEQGEMVQRIDENVEDALANVEAAHSELLKYYRSISSNRWliLKIFGVLIV 80

                ....
gi 30583491 281 SITV 284
Cdd:cd15844  81 FIVI 84

SNARE motif of syntaxin 7, 12 and related sequences; 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 7, syntaxin 12, TSNARE1 and related proteins.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*..
gi 30583491 206 RHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTA 262
Cdd:cd15847   4 REERIRQIESDILDVNQIFKDLATLVHEQGETIDSIEANIESAYVNVESGNSQLAKA 60

SNARE motif of syntaxin 7; Syntaxin 7 forms a complex with syntaxin 8 (Qc), Vti1b (Qb) and either VAMP7 or VAMP8 (R-SNARE) and is involved in the transport from early endosomes to the lysosome. Syntaxin 7 is 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) that 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        60
                ....*....|....*....|....*....|....*....|....*....|....*....|
gi 30583491 203 ISARHSEIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKTA 262
Cdd:cd15875   1 LEERERSIRQLESDIMDVNQIFKDLGMLVHEQGEVIDSIEANVETAAVHVEEANQQLSQA 60

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        50
                ....*....|....*....|....*....|....*....|....*....|
gi 30583491 209 EIQQLERSIRELHDIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEH 258
Cdd:cd15846  10 SWETLQQDLEDLHGLFTDFHQLVHDQGEQVDTIEDNVEEALENVQEGTKN 59