A putative ATPase mediates RNA transcription and capping in a dsRNA virus

Xuekui Yu; Jiansen Jiang; Jingchen Sun; Z Hong Zhou

doi:10.7554/eLife.07901

eLife (Aug 2015)

A putative ATPase mediates RNA transcription and capping in a dsRNA virus

Xuekui Yu,
Jiansen Jiang,
Jingchen Sun,
Z Hong Zhou

Affiliations

Xuekui Yu: Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States; California Nanosystems Institute, University of California, Los Angeles, Los Angeles, United States
Jiansen Jiang: Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States; California Nanosystems Institute, University of California, Los Angeles, Los Angeles, United States
Jingchen Sun: Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States; Subtropical Sericulture and Mulberry Resources Protection and Safety Engineering Research Center, Guangdong Provincial Key Laboratory of Agro-animal Genomics and Molecular Breeding, College of Animal Science, South China Agricultural University, Guangzhou, China
Z Hong Zhou: Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, Los Angeles, United States; California Nanosystems Institute, University of California, Los Angeles, Los Angeles, United States

DOI: https://doi.org/10.7554/eLife.07901
Journal volume & issue: Vol. 4

Abstract

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mRNA transcription in dsRNA viruses is a highly regulated process but the mechanism of this regulation is not known. Here, by nucleoside triphosphatase (NTPase) assay and comparisons of six high-resolution (2.9–3.1 Å) cryo-electron microscopy structures of cytoplasmic polyhedrosis virus with bound ligands, we show that the large sub-domain of the guanylyltransferase (GTase) domain of the turret protein (TP) also has an ATP-binding site and is likely an ATPase. S-adenosyl-L-methionine (SAM) acts as a signal and binds the methylase-2 domain of TP to induce conformational change of the viral capsid, which in turn activates the putative ATPase. ATP binding/hydrolysis leads to an enlarged capsid for efficient mRNA synthesis, an open GTase domain for His217-mediated guanylyl transfer, and an open methylase-1 domain for SAM binding and methyl transfer. Taken together, our data support a role of the putative ATPase in mediating the activation of mRNA transcription and capping within the confines of the virus.

Published in eLife

ISSN: 2050-084X (Online)
Publisher: eLife Sciences Publications Ltd
Country of publisher: United Kingdom
LCC subjects: Medicine; Science: Biology (General)
Website: https://elifesciences.org

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