A structural analysis of M protein in coronavirus assembly and morphology

J Struct Biol. 2011 Apr;174(1):11-22. doi: 10.1016/j.jsb.2010.11.021. Epub 2010 Dec 3.

Abstract

The M protein of coronavirus plays a central role in virus assembly, turning cellular membranes into workshops where virus and host factors come together to make new virus particles. We investigated how M structure and organization is related to virus shape and size using cryo-electron microscopy, tomography and statistical analysis. We present evidence that suggests M can adopt two conformations and that membrane curvature is regulated by one M conformer. Elongated M protein is associated with rigidity, clusters of spikes and a relatively narrow range of membrane curvature. In contrast, compact M protein is associated with flexibility and low spike density. Analysis of several types of virus-like particles and virions revealed that S protein, N protein and genomic RNA each help to regulate virion size and variation, presumably through interactions with M. These findings provide insight into how M protein functions to promote virus assembly.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Line
  • Coronavirus / metabolism*
  • Coronavirus / ultrastructure*
  • Cryoelectron Microscopy
  • Electron Microscope Tomography
  • Humans
  • Viral Matrix Proteins / ultrastructure*
  • Virus Assembly / physiology*
  • Virus Assembly / radiation effects*

Substances

  • M protein, Coronavirus
  • Viral Matrix Proteins