Supramolecular architecture of severe acute respiratory syndrome coronavirus revealed by electron cryomicroscopy.
Coronavirus particles are enveloped and pleomorphic and are thus refractory to crystallization and symmetry-assisted reconstruction. A novel methodology of single-particle image analysis was applied to selected virus features to obtain a detailed model of the oligomeric state and spatial relationships among viral structural proteins. Two-dimensional images of the S, M, and N structural proteins of severe acute respiratory syndrome coronavirus and two other coronaviruses were refined to a resolution of approximately 4 nm. Proteins near the viral membrane were arranged in overlapping lattices surrounding a disordered core. Trimeric glycoprotein spikes were in register with four underlying ribonucleoprotein densities. However, the spikes were dispensable for ribonucleoprotein lattice formation. The ribonucleoprotein particles displayed coiled shapes when released from the viral membrane. Our results contribute to the understanding of the assembly pathway used by coronaviruses and other pleomorphic viruses and provide the first detailed view of coronavirus ultrastructure.
Neuman
Benjamin W
BW
Department of Molecular and Integrative Neuroscience, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA. bneuman@scripps.edu
Adair
Brian D
BD
Yoshioka
Craig
C
Quispe
Joel D
JD
Orca
Gretchen
G
Kuhn
Peter
P
Milligan
Ronald A
RA
Yeager
Mark
M
Buchmeier
Michael J
MJ
D020285:Cryoelectron Microscopy; D012261:Ribonucleoproteins / Q000648:ultrastructure; D045473:Severe acute respiratory syndrome-related coronavirus / Q000648:ultrastructure*; D015678:Viral Structural Proteins / Q000648:ultrastructure*
D012261:Ribonucleoproteins; D015678:Viral Structural Proteins