Member database | PROSITE profiles |
PROSITE profiles type | domain |
Short name | V_SNARE |
Description
The process of vesicular membrane fusion in eukaryotic cells depends on a
conserved fusion machinery called SNARE (soluble N-ethylmaleimide-sensitive
factor (NSF) attachment protein (SNAP) receptors). In the process of vesicle
docking, proteins present on the vesicle (v-SNARE) have to bind to their
counterpart on the target membrane (t-SNARE) to form a core complex that can
then recruit the soluble proteins NSF and SNAP. This so called fusion complex
can then disassemble after ATP hydrolysis mediated by the ATPase NSF in a
process that leads to membrane fusion and the release of the vesicle contents.
v-SNAREs include proteins homologous to synaptobrevin
[2][3][1].
Structurally the SNARE complex is generally a four-helix bundle comprised of
three coiled-coil-forming domains from t-SNAREs and one from
v-SNARE. Although sequence similarity in the t- and v-SNARE
coiled-coil homology domains are low there is a striking conservation of the
so-called heptad repeat that is of central importance in forming a coiled-coil
structure. In a coiled-coil motif, seven residues constitute a canonical
heptad and are designated 'a' through 'g', with 'a' and 'd' being occupied by
hydrophobic residues. The association of the four alpha-helices in the SNARE
fusion complex structure produces highly conserved layers of interacting amino
acid side chains in the center of the four-helix bundle. The center of the
bundle is made up of 15 hydrophobic layers from the 'a' and 'd' positions of
the heptad repeats of the coiled-coil-forming domains, whereas the central
'ionic' layer is highly conserved and polar in nature, containing a glutamine
residue in the three t-SNAREs and an arginine in the v-SNARE, hence the
classification of v- and t-SNAREs as R- and Q-SNAREs, respectively. The v-
SNARE coiled-coil homology domain is around 60 amino acids in length
[2][3][1].
The profile we developed cover the entire v-SNARE coiled-coil homology
domain.
References
1.Amisyn, a novel syntaxin-binding protein that may regulate SNARE complex assembly. Scales SJ, Hesser BA, Masuda ES, Scheller RH. J. Biol. Chem. 277, 28271-9, (2002). View articlePMID: 12145319
2.Phylogenetic analysis of membrane trafficking proteins: a family reunion and secondary structure predictions. Terrian DM, White MK. Eur. J. Cell Biol. 73, 198-204, (1997). PMID: 9243180
3.Conserved structural features of the synaptic fusion complex: SNARE proteins reclassified as Q- and R-SNAREs. Fasshauer D, Sutton RB, Brunger AT, Jahn R. Proc. Natl. Acad. Sci. U.S.A. 95, 15781-6, (1998). View articlePMID: 9861047
Integrated to
External Links
Representative structure
3b5n: Structure of the yeast plasma membrane SNARE complex