title: Three-dimensional structure of the neuronal-Sec1-syntaxin 1a complex.
abstract: Syntaxin 1a and neuronal Sec1 (nSec1) form an evolutionarily conserved heterodimer that is essential for vesicle trafficking and membrane fusion. The crystal structure of the nSec1-syntaxin 1a complex, determined at 2.6 A resolution, reveals that major conformational rearrangements occur in syntaxin relative to both the core SNARE complex and isolated syntaxin. We identify regions of the two proteins that seem to determine the binding specificity of particular Sec1 proteins for syntaxin isoforms, which is likely to be important for the fidelity of membrane trafficking. The structure also indicates mechanisms that might couple the action of upstream effector proteins to conformational changes in syntaxin 1a and nSec1 that lead to core complex formation and membrane fusion.
authors.affiliation: Department of Structural Biology, Stanford University School of Medicine, California 94305, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Misura
authors.forename: R H
authors.initials: RH
authors.lastname: Scheller
authors.forename: W I
authors.initials: WI
authors.lastname: Weis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D001665:Binding Sites; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D004926:Escherichia coli; D046911:Macromolecular Substances; D008561:Membrane Fusion / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D017354:Point Mutation; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D050600:SNARE Proteins; D016415:Sequence Alignment; D055672:Static Electricity; D050827:Syntaxin 1; D033921:Vesicular Transport Proteins
chemical_list: D000954:Antigens, Surface; D046911:Macromolecular Substances; D008565:Membrane Proteins; D051938:Munc18 Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D011994:Recombinant Proteins; D050600:SNARE Proteins; C494213:Stx1a protein, rat; C497939:Stxbp1 protein, rat; D050827:Syntaxin 1; D033921:Vesicular Transport Proteins