Elsevier

Virology

Volume 298, Issue 2, 5 July 2002, Pages 258-270
Virology

Regular Article
Functional Properties of the Predicted Helicase of Porcine Reproductive and Respiratory Syndrome Virus

https://doi.org/10.1006/viro.2002.1495Get rights and content
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Abstract

Porcine reproductive and respiratory syndrome virus (PRRSV) is a member of the positive-strand RNA virus family Arteriviridae. Although considerable research has focused on this important pathogen, little is known about the function of most PRRSV proteins. To examine characteristics of putative nonstructural proteins (nsp) encoded in ORF1b, which have been identified by nucleotide similarity to domains of equine arteritis virus, defined genomic regions were cloned and expressed in the pRSET expression system. One region, nsp10, encoded a protein with a putative helicase domain and was further examined for functional helicase-like activities. PRRSV nsp10 was found to possess a thermolabile and pH-sensitive NTPase activity that was modulated by polynucleotides and to unwind dsRNA in a 5′ to 3′ polarity. These results provide the first evidence of the functional properties of PRRSV helicase and further support the finding that nidovirus helicases possess properties that distinguish them from other viral helicases.

Keywords

PRRSV
arterivirus
coronavirus
Nidovirales
RNA-dependent RNA polymerase
helicase
NTPase

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To whom correspondence and reprint requests should be addressed at United States Department of Agriculture, Plum Island Animal Disease Center, P.O. Box 848, Greenport, NY 11944-0848. Fax: 631-323-3295. E-mail: [email protected].