SNAP-25 (IPR000928)

Short name: SNAP-25

Overlapping homologous superfamilies


Domain relationships



This entry represents a domain found in the SNAP-25 family members. SNAP-25 (synaptosome-associated protein 25 kDa) proteins are components of SNARE complexes, which are proposed to account for the specificity of membrane fusion and to directly execute fusion by forming a tight complex (the SNARE or core complex) that brings the synaptic vesicle and plasma membranes together. The SNAREs constitute a large family of proteins that are characterised by 60-residue sequences known as SNARE motifs (IPR000727), which have a high propensity to form coiled coils and often precede carboxy-terminal transmembrane regions. The synaptic core complex is formed by four SNARE motifs (two from SNAP25 and one each from synaptobrevin and syntaxin 1) that are unstructured in isolation but form a parallel four-helix bundle on assembly. The crystal structure of the core complex revealed that the helix bundle is highly twisted and contains several salt bridges on the surface, as well as layers of interior hydrophobic residues. However, a polar layer in the centre of the complex is formed by three glutamines (two from SNAP25 and one from syntaxin 1) and one arginine (from synaptobrevin) [PMID: 12154365].

Members of the SNAP-25 family contain a cluster of cysteine residues that can be palmitoylated for membrane attachment [PMID: 8226991].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.