Molecular interactions in rotavirus assembly and uncoating seen by high-resolution cryo-EM.
Rotaviruses, major causes of childhood gastroenteritis, are nonenveloped, icosahedral particles with double-strand RNA genomes. By the use of electron cryomicroscopy and single-particle reconstruction, we have visualized a rotavirus particle comprising the inner capsid coated with the trimeric outer-layer protein, VP7, at a resolution (4 A) comparable with that of X-ray crystallography. We have traced the VP7 polypeptide chain, including parts not seen in its X-ray crystal structure. The 3 well-ordered, 30-residue, N-terminal "arms" of each VP7 trimer grip the underlying trimer of VP6, an inner-capsid protein. Structural differences between free and particle-bound VP7 and between free and VP7-coated inner capsids may regulate mRNA transcription and release. The Ca(2+)-stabilized VP7 intratrimer contact region, which presents important neutralizing epitopes, is unaltered upon capsid binding.
Chen
James Z
JZ
Rosenstiel Basic Medical Research Center, Brandeis University, Waltham, MA 02454, USA.
Settembre
Ethan C
EC
Aoki
Scott T
ST
Zhang
Xing
X
Bellamy
A Richard
AR
Dormitzer
Philip R
PR
Harrison
Stephen C
SC
Grigorieff
Nikolaus
N
D000956:Antigens, Viral / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D002118:Calcium / Q000378:metabolism; D036022:Capsid Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D020285:Cryoelectron Microscopy / Q000379:methods*; D018360:Crystallography, X-Ray; D008954:Models, Biological; D008958:Models, Molecular; D055503:Protein Multimerization; D020836:Protein Structure, Quaternary; D012401:Rotavirus / Q000378:metabolism / Q000648:ultrastructure*; D014758:Viral Core Proteins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D014771:Virion / Q000378:metabolism / Q000648:ultrastructure*
D000956:Antigens, Viral; D036022:Capsid Proteins; C069187:VP1 protein, Rotavirus; C442545:VP2 protein, Rotavirus; C442546:VP3 protein, Rotavirus; C050779:VP7 protein, Rotavirus; D014758:Viral Core Proteins; D002118:Calcium