The evolutionarily conserved SNARE proteins and their complexes are involved in the fusion of vesicles with their target membranes; however, the overall organization and structural details of these complexes are unknown. Here we report the X-ray crystal structure at 2.4 A resolution of a core synaptic fusion complex containing syntaxin-1 A, synaptobrevin-II and SNAP-25B. The structure reveals a highly twisted and parallel four-helix bundle that differs from the bundles described for the haemagglutinin and HIV/SIV gp41 membrane-fusion proteins. Conserved leucine-zipper-like layers are found at the centre of the synaptic fusion complex. Embedded within these leucine-zipper layers is an ionic layer consisting of an arginine and three glutamine residues contributed from each of the four alpha-helices. These residues are highly conserved across the entire SNARE family. The regions flanking the leucine-zipper-like layers contain a hydrophobic core similar to that of more general four-helix-bundle proteins. The surface of the synaptic fusion complex is highly grooved and possesses distinct hydrophilic, hydrophobic and charged regions. These characteristics may be important for membrane fusion and for the binding of regulatory factors affecting neurotransmission.
|Evidence ID||Analyze ID||Interactor||Interactor Systematic Name||Interactor||Interactor Systematic Name||Type||Assay||Annotation||Action||Modification||Phenotype||Source||Reference||Note|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Gene Ontology Term||Gene Ontology Term ID||Qualifier||Aspect||Method||Evidence||Source||Assigned On||Reference||Annotation Extension|
|Evidence ID||Analyze ID||Gene||Gene Systematic Name||Phenotype||Experiment Type||Experiment Type Category||Mutant Information||Strain Background||Chemical||Details||Reference|
|Evidence ID||Analyze ID||Regulator||Regulator Systematic Name||Target||Target Systematic Name||Experiment||Conditions||Strain||Source||Reference|