The structure of the yeast plasma membrane SNARE complex reveals destabilizing water-filled cavities.
SNARE proteins form a complex that leads to membrane fusion between vesicles, organelles, and plasma membrane in all eukaryotic cells. We report the 1.7A resolution structure of the SNARE complex that mediates exocytosis at the plasma membrane in the yeast Saccharomyces cerevisiae. Similar to its neuronal and endosomal homologues, the S. cerevisiae SNARE complex forms a parallel four-helix bundle in the center of which is an ionic layer. The S. cerevisiae SNARE complex exhibits increased helix bending near the ionic layer, contains water-filled cavities in the complex core, and exhibits reduced thermal stability relative to mammalian SNARE complexes. Mutagenesis experiments suggest that the water-filled cavities contribute to the lower stability of the S. cerevisiae complex.
Strop
Pavel
P
Howard Hughes Medical Institute and Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305, USA.
Kaiser
Stephen E
SE
Vrljic
Marija
M
Brunger
Axel T
AT
D000818:Animals; D001665:Binding Sites; D002462:Cell Membrane / Q000502:physiology*; D018360:Crystallography, X-Ray; D011992:Endosomes / Q000502:physiology; D005089:Exocytosis; D008958:Models, Molecular; D016296:Mutagenesis; D009474:Neurons / Q000502:physiology; D011487:Protein Conformation; D050683:R-SNARE Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D014867:Water
D050683:R-SNARE Proteins; D011994:Recombinant Proteins; C083241:SNC1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014867:Water