Format

Send to

Choose Destination
EMBO J. 1987 Apr;6(4):1099-105.

Is Sindbis a simple picornavirus with an envelope?

Abstract

A three-dimensional image reconstruction was performed from cryo-electron micrographs of isolated Sindbis (SNV) nucleocapsids. The isolated capsid is a smooth but fenestrated T = 3 structure. Comparison with the nucleocapsid seen within the whole virion indicated that the structure resembles the swollen forms which some non-enveloped viruses adopt after removal of divalent cations. A sensitive comparison method was used to align SNV capsid protein sequences with those of picornavirus vp3 capsid proteins whose high resolution structures display an eight-stranded beta-barrel fold found in many icosahedral viruses. The alignment predicted a similar folding for the Sindbis protein which juxtaposes several sets of residues known to be essential for its serine proteolytic activity. These results suggest that the capsid proteins of the enveloped alphaviruses and the non-enveloped picornaviruses may have arisen through divergent evolution from a simple, vp3-like ancestor.

PMID:
3595557
PMCID:
PMC553508
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Wiley Icon for PubMed Central
Loading ...
Support Center