A structural analysis of M protein in coronavirus assembly and morphology.
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.
School of Biological Sciences, University of Reading, RG6 6AJ, UK. b.w.neuman@reading.ac.uk
Benjamin W
BW
Neuman
Gabriella
G
Kiss
Andreas H
AH
Kunding
David
D
Bhella
M Fazil
MF
Baksh
Stephen
S
Connelly
Ben
B
Droese
Joseph P
JP
Klaus
Shinji
S
Makino
Stanley G
SG
Sawicki
Stuart G
SG
Siddell
Dimitrios G
DG
Stamou
Ian A
IA
Wilson
Peter
P
Kuhn
Michael J
MJ
Buchmeier
D002460:Cell Line; D017934:Coronavirus / Q000378:metabolism* / Q000648:ultrastructure*; D000086862:Coronavirus M Proteins; D020285:Cryoelectron Microscopy; D055032:Electron Microscope Tomography; D006801:Humans; D014763:Viral Matrix Proteins / Q000648:ultrastructure*; D019065:Virus Assembly / Q000502:physiology* / Q000528:radiation effects*
D000086862:Coronavirus M Proteins; D014763:Viral Matrix Proteins