3c98
Revised structure of the munc18a-syntaxin1 complex
OverviewOverview
Sec1/Munc18-like (SM) proteins functionally interact with SNARE proteins in vesicular fusion. Despite their high sequence conservation, structurally disparate binding modes for SM proteins with syntaxins have been observed. Several SM proteins appear to bind only to a short peptide present at the N terminus of syntaxin, designated the N-peptide, while Munc18a binds to a 'closed' conformation formed by the remaining portion of syntaxin 1a. Here, we show that the syntaxin 16 N-peptide binds to the SM protein Vps45, but the remainder of syntaxin 16 strongly enhances the affinity of the interaction. Likewise, the N-peptide of syntaxin 1a serves as a second binding site in the Munc18a/syntaxin 1a complex. When the syntaxin 1a N-peptide is bound to Munc18a, SNARE complex formation is blocked. Removal of the N-peptide enables binding of syntaxin 1a to its partner SNARE SNAP-25, while still bound to Munc18a. This suggests that Munc18a controls the accessibility of syntaxin 1a to its partners, a role that might be common to all SM proteins.
About this StructureAbout this Structure
3C98 is a Protein complex structure of sequences from Rattus norvegicus. This structure supersedes the now removed PDB entry 1dn1. Full crystallographic information is available from OCA.
ReferenceReference
Munc18a controls SNARE assembly through its interaction with the syntaxin N-peptide., Burkhardt P, Hattendorf DA, Weis WI, Fasshauer D, EMBO J. 2008 Mar 13;. PMID:18337752 Page seeded by OCA on Wed Apr 30 13:39:25 2008