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 6678177   39 DEFFQKVQTIRQTMAKLESKVRELEKQQVTILATPLPEESMKQGLQNLREEIKQLGREVRAQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 6678177  119 NTRMKKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 189
Cdd:cd00179  82 VDRIRKTQHSGLSKKFVEVMTEFNKAQRKYRERYKERIQRQLEITG-GEATDEELEDMLESGNSEIFTSQI 151

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 6678177    236 EMINRIEKNILSSADYVERGQEHVKIALENQKKARKKKVMIAICVSVTVLIL 287
Cdd:pfam05739   1 EMLDRIDTNVENAQSNVERAQKELKKAVKYQKSNRKLKCIILLILVIILLVV 52

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 6678177   39 DEFFQKVQTIRQTMAKLESKVRELEKQQVTILATPLPEESMKQGLQNLREEIKQLGREVRAQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 6678177  119 NTRMKKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 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 6678177  199 ALNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVK 260
Cdd:cd15883   1 ALNEIEARHSEIQKLERSIRELHDMFTYLAMEVEAQGEMIDRIEKNILSSADYVEKAQEHVK 62

Syntaxin N-terminal domain; Three-helix domain that (in Sso1p) slows the rate of its reaction with the SNAP-25 homologue Sec9p

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 6678177      36 SPDDEFFQKVQTIRQTMAKLESKVRELEKQQVTILATPLPEESMKQGLQNLREEIKQLGREVRAQLKAIEPQKEEADENy 115
Cdd:smart00503   1 SNLDEFFEKVEEIRANIQKISQNVAELQKLHEELLTPPDADKELREKLERLIDDIKRLAKEIRAKLKELEKENLENRAS- 79

                           90       100       110
                   ....*....|....*....|....*....|....*.
gi 6678177     116 NSVNTRMKKTQHGVLSQQFVELINKCNSMQSEYREK 151
Cdd:smart00503  80 GSASDRTRKAQTEKLRKKFKEVMNEFQRLQRKYRER 115

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 6678177    236 EMINRIEKNILSSADYVERGQEHVKIALENQKKARKKKVMIAICVSVTVLIL 287
Cdd:pfam05739   1 EMLDRIDTNVENAQSNVERAQKELKKAVKYQKSNRKLKCIILLILVIILLVV 52

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 6678177   39 DEFFQKVQTIRQTMAKLESKVRELEKQQVTILATPLPEESMKQGLQNLREEIKQLGREVRAQLKAIEPQKEEADENYNSV 118
Cdd:cd00179   2 EEFFEEVEEIRGNIDKISEDVEELQKLHSQLLTAPDADPELKQELESLVQEIKKLAKEIKGKLKELEESNEQNEALNGSS 81

                        90       100       110       120       130       140       150
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 6678177  119 NTRMKKTQHGVLSQQFVELINKCNSMQSEYREKNVERIRRQLKITNaGMVSDEELEQMLDSGQSEVFVSNI 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 6678177  199 ALNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVK 260
Cdd:cd15883   1 ALNEIEARHSEIQKLERSIRELHDMFTYLAMEVEAQGEMIDRIEKNILSSADYVEKAQEHVK 62

Syntaxin N-terminal domain; Three-helix domain that (in Sso1p) slows the rate of its reaction with the SNAP-25 homologue Sec9p

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 6678177      36 SPDDEFFQKVQTIRQTMAKLESKVRELEKQQVTILATPLPEESMKQGLQNLREEIKQLGREVRAQLKAIEPQKEEADENy 115
Cdd:smart00503   1 SNLDEFFEKVEEIRANIQKISQNVAELQKLHEELLTPPDADKELREKLERLIDDIKRLAKEIRAKLKELEKENLENRAS- 79

                           90       100       110
                   ....*....|....*....|....*....|....*.
gi 6678177     116 NSVNTRMKKTQHGVLSQQFVELINKCNSMQSEYREK 151
Cdd:smart00503  80 GSASDRTRKAQTEKLRKKFKEVMNEFQRLQRKYRER 115

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 6678177  199 ALNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKIALENQ 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 6678177  199 ALNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKIALENQK 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 6678177  203 ISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVK 260
Cdd:cd15840   1 IEEREEEIREIESSIGEVNEIFKDLATLVTEQGEQIDNIENNIEEAAANTEEANKELR 58

SNARE motif of syntaxin 11; Syntaxin 11 (also known as STX11, FHL4, HLH4, HPLH4) is present on endosomal membranes, including late endosomes and lysosomes in macrophages, and has been shown to bind Vti1b and regulate the availability of Vti1b to form other SNARE-complexes. Mutations in human STX11 has been linked to familial hemophagocytic lymphohistiocytosis type-4 (FHL-4), an autosomal recessive disorder of immune dysregulation. Syntaxin 11 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 6678177  199 ALNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVK 260
Cdd:cd15878   1 ALNEIETRHKELLELESRIREVHELFLQMALLVEEQADTLNNIELNVEKTQDYVGKAKAQVK 62

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 6678177  200 LNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKIA 262
Cdd:cd15849   1 LGEVQARHNEIQRIEQTLTELAQLFNDMATLVEQQDEVIQQIEQNAEEVETDLEKGNVHLEKA 63

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
                ....*....|....*....|....*....|....*....|....*....|....*.
gi 6678177  203 ISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEH 258
Cdd:cd15844   1 LQSRADAVQNIESTIVELGQIFQQLATMVAEQGEMVQRIDENVEDALANVEAAHSE 56

SNARE motif of syntaxin 19; Syntaxin 19 has been shown to have the potential to form SNARE complexes with SNAP-23, 25 and 29 (Qb/Qc) and VAMP3 and VAMP8 (R-SNARE), indicating a role in post-Golgi trafficking or plasma membrane fusion. Syntaxin 19 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 6678177  200 LNEISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKI 261
Cdd:cd15879   2 LSEIEQRHKELVSLENQIKDLKDLFIQISLLVEEQGEMINNIEISVNNTQEYVQASKEKFGL 63

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 6678177  203 ISARHSEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVERGQEHVKIA 262
Cdd:cd15875   1 LEERERSIRQLESDIMDVNQIFKDLGMLVHEQGEVIDSIEANVETAAVHVEEANQQLSQA 60

SNARE motif; 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-, 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.

                        10        20        30        40
                ....*....|....*....|....*....|....*....|....*..
gi 6678177  208 SEIQQLERSIRELHEIFTFLATEVEMQGEMINRIEKNILSSADYVER 254
Cdd:cd00193   1 ESLEQLEASIGELKDIGRDMAMELEEQGEQLDRIEERAESTQARVSR 47