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
                 ....*....|....*....|....*....|..
gi 767938598 175 AQTSSTITESLMGISRMMAQQVQQSEEAMQSL 206
Cdd:cd15865    1 AKTSSQITENLLRISRMLASQVQQSELTLQEL 32

SNARE motif of SEC20; SEC20 (also known as BNIP1, NIP1, or TRG-8) forms a complex with syntaxin 18 (Qa), SEC22 (R-SNARE)and USE1 (Qc), and is involved in the transport from cis-Golgi to the endoplasmic reticulum (ER). SEC20 is a member of the Qb subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins which contain 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. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles.

                         10        20        30
                 ....*....|....*....|....*....|..
gi 767938598 175 AQTSSTITESLMGISRMMAQQVQQSEEAMQSL 206
Cdd:cd15865    1 AKTSSQITENLLRISRMLASQVQQSELTLQEL 32

SNARE motif of SEC20; SEC20 (also known as BNIP1, NIP1, or TRG-8) forms a complex with syntaxin 18 (Qa), SEC22 (R-SNARE)and USE1 (Qc), and is involved in the transport from cis-Golgi to the endoplasmic reticulum (ER). SEC20 is a member of the Qb subfamily of SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptor) proteins which contain 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. Their SNARE motifs form twisted and parallel heterotetrameric helix bundles.

                         10        20        30
                 ....*....|....*....|....*....|..
gi 767938598 175 AQTSSTITESLMGISRMMAQQVQQSEEAMQSL 206
Cdd:cd15865    1 AKTSSQITENLLRISRMLASQVQQSELTLQEL 32

SNARE motif, subgroup Qb; 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 Qb SNAREs are N-terminal domains of SNAP23 and SNAP25, Vti1, Sec20 and GS27.

                         10        20        30
                 ....*....|....*....|....*....|...
gi 767938598 175 AQTSSTITESLMGISRMMAQQVQQSEEAMQSLG 207
Cdd:cd15842    1 DQLSDQSTESLRRSHRGMEELKQAGIETLEMLD 33