Demonstration of helicase activity in the nonstructural protein, NSs, of the negative-sense RNA virus, Groundnut bud necrosis virus

Bhushan, Lokesh and Abraham, Ambily and Choudhury, Nirupam Roy and Rana, Vipin Singh and Mukherjee, Sunil Kumar and Savithri, Handanahal Subbarao (2015) Demonstration of helicase activity in the nonstructural protein, NSs, of the negative-sense RNA virus, Groundnut bud necrosis virus. In: ARCHIVES OF VIROLOGY, 160 (4). pp. 959-967.

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Abstract

The nonstructural protein NSs, encoded by the S RNA of groundnut bud necrosis virus (GBNV) (genus Tospovirus, family Bunyaviridae) has earlier been shown to possess nucleic-acid-stimulated NTPase and 50 a phosphatase activity. ATP hydrolysis is an essential function of a true helicase. Therefore, NSs was tested for DNA helicase activity. The results demonstrated that GBNV NSs possesses bidirectional DNA helicase activity. An alanine mutation in the Walker A motif (K189A rNSs) decreased DNA helicase activity substantially, whereas a mutation in the Walker B motif resulted in a marginal decrease in this activity. The parallel loss of the helicase and ATPase activity in the K189A mutant confirms that NSs acts as a non-canonical DNA helicase. Furthermore, both the wild-type and K189A NSs could function as RNA silencing suppressors, demonstrating that the suppressor activity of NSs is independent of its helicase or ATPase activity. This is the first report of a true helicase from a negative-sense RNA virus.

Item Type:	Journal Article
Publication:	ARCHIVES OF VIROLOGY
Publisher:	SPRINGER WIEN
Additional Information:	Copy right for this article belongs to the SPRINGER WIEN, SACHSENPLATZ 4-6, PO BOX 89, A-1201 WIEN, AUSTRIA
Keywords:	SPOTTED-WILT-VIRUS; HEMORRHAGIC-FEVER VIRUS; DNA HELICASE; SILENCING SUPPRESSOR; BENTHAMIANA LEAVES; VIRAL REPLICATION; INFECTION; GENE; ROLES; COMPLEX
Department/Centre:	Division of Biological Sciences > Biochemistry
Date Deposited:	23 Apr 2015 07:39
Last Modified:	23 Apr 2015 07:39
URI:	http://eprints.iisc.ac.in/id/eprint/51355

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