In:
Journal of Virology, American Society for Microbiology, Vol. 80, No. 16 ( 2006-08-15), p. 7894-7901
Abstract:
The severe acute respiratory syndrome coronavirus (SARS-CoV) possesses a large 29.7-kb positive-stranded RNA genome. The first open reading frame encodes replicase polyproteins 1a and 1ab, which are cleaved to generate 16 “nonstructural” proteins, nsp1 to nsp16, involved in viral replication and/or RNA processing. Among these, nsp10 plays a critical role in minus-strand RNA synthesis in a related coronavirus, murine hepatitis virus. Here, we report the crystal structure of SARS-CoV nsp10 at a resolution of 1.8 Å as determined by single-wavelength anomalous dispersion using phases derived from hexatantalum dodecabromide. nsp10 is a single domain protein consisting of a pair of antiparallel N-terminal helices stacked against an irregular β-sheet, a coil-rich C terminus, and two Zn fingers. nsp10 represents a novel fold and is the first structural representative of this family of Zn finger proteins found so far exclusively in coronaviruses. The first Zn finger coordinates a Zn 2+ ion in a unique conformation. The second Zn finger, with four cysteines, is a distant member of the “gag-knuckle fold group” of Zn 2+ -binding domains and appears to maintain the structural integrity of the C-terminal tail. A distinct clustering of basic residues on the protein surface suggests a nucleic acid-binding function. Gel shift assays indicate that in isolation, nsp10 binds single- and double-stranded RNA and DNA with high-micromolar affinity and without obvious sequence specificity. It is possible that nsp10 functions within a larger RNA-binding protein complex. However, its exact role within the replicase complex is still not clear.
Type of Medium:
Online Resource
ISSN:
0022-538X
,
1098-5514
DOI:
10.1128/JVI.00467-06
Language:
English
Publisher:
American Society for Microbiology
Publication Date:
2006
detail.hit.zdb_id:
1495529-5
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