N-terminal SNARE motif of SNAP23; N-terminal SNARE motifs of SNAP23, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP23 interacts with Syntaxin-4 (Qa) and the R-SNARE VAMP8. The complex plays a role in exocytosis of secretory granule. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP25, SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 295317330   9 VQLRAHQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 75
Cdd:cd15895    1 IQLRANQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 67

SNAP-25 family; SNAP-25 (synaptosome-associated protein 25 kDa) proteins are components of SNARE complexes. Members of this family contain a cluster of cysteine residues that can be palmitoylated for membrane attachment.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 295317330   86 PCNRTKNFESGKNYKATWgdgGDNSPSNVVSKQPSRITNGqpqQTTGAASGGYIKRITNDAR 147
Cdd:pfam00835   1 PCKRTKNFEKGKAYKATW---GGNEDGKVVSSQPSRVGDG---REGMGPSGGYITRITNDAR 56

N-terminal SNARE motif of SNAP23; N-terminal SNARE motifs of SNAP23, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP23 interacts with Syntaxin-4 (Qa) and the R-SNARE VAMP8. The complex plays a role in exocytosis of secretory granule. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP25, SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 295317330   9 VQLRAHQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 75
Cdd:cd15895    1 IQLRANQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 67

SNAP-25 family; SNAP-25 (synaptosome-associated protein 25 kDa) proteins are components of SNARE complexes. Members of this family contain a cluster of cysteine residues that can be palmitoylated for membrane attachment.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 295317330   86 PCNRTKNFESGKNYKATWgdgGDNSPSNVVSKQPSRITNGqpqQTTGAASGGYIKRITNDAR 147
Cdd:pfam00835   1 PCKRTKNFEKGKAYKATW---GGNEDGKVVSSQPSRVGDG---REGMGPSGGYITRITNDAR 56

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 295317330    12 RAHQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTEL 76
Cdd:smart00397   2 QALAREEERDEELEQLEKSIQELKQIFLDMGTELEEQGEQLDRIEDNVDDADVNLKKANKRLKKA 66

N-terminal SNARE motif of SNAP23; N-terminal SNARE motifs of SNAP23, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP23 interacts with Syntaxin-4 (Qa) and the R-SNARE VAMP8. The complex plays a role in exocytosis of secretory granule. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP25, SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 295317330   9 VQLRAHQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 75
Cdd:cd15895    1 IQLRANQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTE 67

N-terminal SNARE motif of SNAP25; N-terminal SNARE motifs of SNAP25, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP25 interacts with Syntaxin-1 (Qa) and the R-SNARE VAMP2 (also called synaptobrevin-2). The complex plays a role in transport of secretory granule from trans-Golgi network to the plasma membrane. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 295317330   7 EEVQLRAHQVTDESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLTEL 76
Cdd:cd15894    3 EEMQRRADQLADESLESTRRMLQLVEESKDAGIRTLVMLDEQGEQLDRVEEGMNHINQDMKEAEKNLKDL 72

C-terminal SNARE motif of SNAP25; C-terminal SNARE motifs of SNAP25, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP25 interacts with Syntaxin-1 (Qa) and the R-SNARE VAMP2 (also called synaptobrevin-2). The complex plays a role in transport of secretory granule from trans-Golgi network to the plasma membrane. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 295317330 148 EDEMEENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15885    1 EDEMEENLGQVSGMIGNLRNMAIDMGSEIESQNRQIDRINEKAESNETRIDSANKRATK 59

C-terminal SNARE motif of SNAP25 and SNAP23; C-terminal SNARE motifs of SNAP25 and SNAP23, members of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP23 interacts with STX4 (Qa) and the lysosomal R-SNARE VAMP8. The complex plays a role in transport of secretory granule from trans-Golgi network to the plasma membrane. SNAP25 interacts with Syntaxin-1 (Qa) and the R-SNARE VAMP2 (also called synaptobrevin-2). The complex plays a role in transport of secretory granule from trans-Golgi network to the plasma membrane. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP29, SNAP47 and SEC9.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 295317330 148 EDEMEENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15855    1 EDEMDENLQQVSGILGNLRHMALDMGNEIDTQNRQLDRIDEKADSNKTRIEAANDRATK 59

C-terminal SNARE motif of SEC9; C-terminal SNARE motif of fungal SEC9, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SEC9 interacts with Sso1(Qa) and the lysosomal R-SNARE Snc1. The complex plays a role in post-Golgi transport. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP25, SNAP47 and SNAP29.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 295317330 148 EDEMEENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15857    1 EDEIDDNLDEIGGVVGRLKALAMAMGEEVDSQNKRLDRIEEKTDRLDDKVHMNTERLKR 59

N-terminal SNARE motif of SNAP29; N-terminal SNARE motif of SNAP29, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP29 interacts with STX17 (Qa) 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. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP25, SNAP47 and SEC9.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*..
gi 295317330  18 DESLESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLT 74
Cdd:cd15887    8 QRTLDSTQRSLGLLYESEQIGVATAEELVRQGEQLERTEKNLDKINQDLKTSQRHIN 64

C-terminal SNARE motif of SNAP29; C-terminal SNARE motif of SNAP29, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. SNAP29 interacts with STX17 (Qa) 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. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP25, SNAP47 and SEC9.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*....
gi 295317330 148 EDEMEENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15856    1 DQQLDENLDEMSSGLSRLKGLALGLGTEIDSQNDLLDRITDKADKADIKIKKQNKQMNK 59

SNARE motif, subgroup Qc; 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). Qc-, as well as Qa- and Qb-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 Qc SNAREs are C-terminal domains of SNAP23 and SNAP25, syntaxin 8, syntaxin 6, and Bet1.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 295317330 149 DEMEENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15841    2 KEQDEQLDELSGSVGRLKNIALAINEELDLQNRLLDDLDEDVDKTQSRLKKVNKKLKK 59

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        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 295317330  22 ESTRRILGLAIESQDAGIKTITMLDEQGEQLNRIEEGMDQINKDMREAEKTLT 74
Cdd:cd00193    1 ESLEQLEASIGELKDIGRDMAMELEEQGEQLDRIEERAESTQARVSRAEKSLA 53

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        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 295317330 153 ENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd00193    1 ESLEQLEASIGELKDIGRDMAMELEEQGEQLDRIEERAESTQARVSRAEKSLAK 54

C-terminal SNARE motif of SNAP47; C-terminal SNARE motif of SNAP47, a member of the Qb/Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins. The exact funtion of SNAP47 is unknown. Qb/Qc SNAREs consist of 2 coiled-coil helices (called SNARE motifs, one belonging to the Qb subgroup and one belonging to the Qc subgroup), which mediate the interactions with other SNARE proteins, and a transmembrane domain. In general, 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. Other members of the Qb/Qc SNAREs are SNAP23, SNAP25, SNAP29 and SEC9.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 295317330 152 EENLTQVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15854    5 EAETQELKQILRKLKSLALEAETELERQDEALDVLSDSVDRATLNIDKHNRRMKK 59

SNARE motif of USE1; USE1 (unconventional SNARE in the ER 1 homolog, also known as SNARE-like tail-anchored protein 1 or SLT1) is involved in retrograde transport of CopI coatomer coated vesicles from the Golgi to the ER. It forms a complex with syntaxin18 (Ufe1p, Qa), Bnip1 (Sec20p, Qb) and Sec22b (R-SNARE). USE1 is a member of the Qc subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) protein family. SNARE 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). Qc-, as well as Qa- and Qb-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        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|
gi 295317330 148 EDEMEENLT-QVGSILGNLKNMALDMGNEIDAQNQQIQKITEKADTNKNRIDIANTRAKK 206
Cdd:cd15860    1 HRNLQEELAeELLSLARQLKENALAFSNILKEDNKVLEATEKLADRNLDKLKRESGRLEE 60