We have constructed a structural model for poliovirus RNA-dependent RNA polymerase (3D(pol)) in complex with a primer-template (sym/sub) and ATP. Residues found in conserved structural motifs A (Asp-238) and B (Asn-297) are involved in nucleotide selection. Asp-238 appears to couple binding of nucleotides with the correct sugar configuration to catalytic efficiency at the active site of the enzyme. Asn-297 is involved in selection of ribonucleoside triphosphates over 2'-dNTPs, a role mediated most likely via a hydrogen bond between the side chain of this residue and the 2'-OH of the ribonucleoside triphosphate. Substitutions at position 238 or 297 of 3D(pol) produced derivatives exhibiting a range of catalytic efficiencies when assayed in vitro for poly(rU) polymerase activity or sym/sub elongation activity. A direct correlation existed between activity on sym/sub and biological phenotypes; a 2.5-fold reduction in polymerase elongation rate produced virus with a temperature-sensitive growth phenotype. These data permit us to propose a detailed, structural model for nucleotide selection by 3D(pol), confirm the biological relevance of the sym/sub system, and provide additional evidence for kinetic coupling between RNA synthesis and subsequent steps in the virus life cycle.
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http://dx.doi.org/10.1074/jbc.M002671200 | DOI Listing |
Virus Res
January 2024
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases (NITFID). National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, No.155 Changbai Road, Beijing 102206, China; WHO WPRO Regional Polio Reference Laboratory, National Health Commission Key Laboratory for Biosafety, National Institute for Viral Disease Control and Prevention, Chinese Center for Disease Control and Prevention, No.155 Changbai Road, Beijing 102206, China. Electronic address:
Hand, foot, and mouth disease (HFMD) caused by a group of enteroviruses is a global public health problem. In recent years, coxsackievirus A6 (CVA6) has emerged as an important HFMD agent. Previous studies have shown that mutations of glycine 64 in RNA-dependent RNA polymerase (3D polymerase), which is central to viral replication, cause phenotypic changes such as ribavirin resistance, increased replication fidelity, and virulence attenuation in poliovirus and enterovirus A71.
View Article and Find Full Text PDFJ Biol Chem
November 2023
Department of Biochemistry & Molecular Birology, Colorado State University, Fort Collins, Colorado, USA. Electronic address:
Positive-strand RNA viruses use long open reading frames to express large polyproteins that are processed into individual proteins by viral proteases. Polyprotein processing is highly regulated and yields intermediate species with different functions than the fully processed proteins, increasing the biochemical diversity of the compact viral genome while also presenting challenges in that proteins must remain stably folded in multiple contexts. We have used circular dichroism spectroscopy and single molecule microscopy to examine the solution structure and self-association of the poliovirus P3 region protein composed of membrane binding 3A, RNA priming 3B (VPg), 3C protease, and 3D RNA-dependent RNA polymerase proteins.
View Article and Find Full Text PDFBiol Trace Elem Res
April 2024
Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia.
Due to their unique properties and their potential therapeutic and prophylactic applications, heavy metals have attracted the interest of many researchers, especially during the outbreak of COVID-19. Indeed, zinc (Zn) and copper (Cu) have been widely used during viral infections. Zn has been reported to prevent excessive inflammatory response and cytokine storm, improve the response of the virus to Type I interferon (IFN-1), and enhance the production of IFN-a to counteract the antagonistic effect of SARS-CoV-2 virus protein on IFN.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
August 2023
Department of Biology, Stanford University, Stanford, CA 94305.
RNA viruses rapidly adapt to selective conditions due to the high intrinsic mutation rates of their RNA-dependent RNA polymerases (RdRps). Insertions and deletions (indels) in viral genomes are major contributors to both deleterious mutational load and evolutionary novelty, but remain understudied. To characterize the mechanistic details of their formation and evolutionary dynamics during infection, we developed a hybrid experimental-bioinformatic approach.
View Article and Find Full Text PDFVirol Sin
August 2023
Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430207, China; University of Chinese Academy of Sciences, Beijing, 100049, China; Hubei Jiangxia Laboratory, Wuhan, 430207, China. Electronic address:
The Dicistroviridae is a virus family that includes many insect pathogens. These viruses contain a positive-sense RNA genome that is replicated by the virally encoded RNA-dependent RNA polymerase (RdRP) also named 3D. Compared with the Picornaviridae RdRPs such as poliovirus (PV) 3D, the Dicistroviridae representative Israeli acute paralysis virus (IAPV) 3D has an additional N-terminal extension (NE) region that is about 40-residue in length.
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