Cryo-EM structure of SNAP-SNARE assembly in 20S particle

Cell Res. 2015 May;25(5):551-60. doi: 10.1038/cr.2015.47. Epub 2015 Apr 24.

Abstract

N-ethylmaleimide-sensitive factor (NSF) and α soluble NSF attachment proteins (α-SNAPs) work together within a 20S particle to disassemble and recycle the SNAP receptor (SNARE) complex after intracellular membrane fusion. To understand the disassembly mechanism of the SNARE complex by NSF and α-SNAP, we performed single-particle cryo-electron microscopy analysis of 20S particles and determined the structure of the α-SNAP-SNARE assembly portion at a resolution of 7.35 Å. The structure illustrates that four α-SNAPs wrap around the single left-handed SNARE helical bundle as a right-handed cylindrical assembly within a 20S particle. A conserved hydrophobic patch connecting helices 9 and 10 of each α-SNAP forms a chock protruding into the groove of the SNARE four-helix bundle. Biochemical studies proved that this structural element was critical for SNARE complex disassembly. Our study suggests how four α-SNAPs may coordinate with the NSF to tear the SNARE complex into individual proteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Cricetulus
  • Cryoelectron Microscopy / methods*
  • Membrane Fusion / physiology
  • N-Ethylmaleimide-Sensitive Proteins / chemistry
  • N-Ethylmaleimide-Sensitive Proteins / metabolism*
  • Protein Binding
  • Protein Structure, Secondary
  • Rats
  • SNARE Proteins / chemistry
  • SNARE Proteins / metabolism
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins / chemistry
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins / metabolism*

Substances

  • SNARE Proteins
  • Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins
  • N-Ethylmaleimide-Sensitive Proteins