RNA-dependent RNA polymerase

About: RNA-dependent RNA polymerase is a research topic. Over the lifetime, 13904 publications have been published within this topic receiving 767954 citations. The topic is also known as: RdRp & RNA replicase.

A Role for the RNase III Enzyme DCR-1 in RNA Interference and Germ Line Development in Caenorhabditis elegans

Abstract: An early event in RNA interference (RNAi) is the cleavage of the initiating double-stranded RNA (dsRNA) to short pieces, 21 to 23 nucleotides in length. Here we describe a null mutation in dicer-1 (dcr-1), a gene proposed to encode the enzyme that generates these short RNAs. We find that dcr-1(-/-) animals have defects in RNAi under some, but not all, conditions. Mutant animals have germ line defects that lead to sterility, suggesting that cleavage of dsRNA to short pieces is a requisite event in normal development.

Cucumber Mosaic Virus

Abstract: Publisher Summary Cucumber mosaic virus (CMV), the type member of the cucumovirus group, was first reported in 1916 as the causal agent of a disease of cucumber and muskmelon in Michigan and cucumber in New York. Since then, CMV has been found in most countries of the world, predominantly in the temperate zones, but increasingly more often in the tropical countries. CMV has the largest host range of any virus. The number of plant species identified as hosts for CMV has increased steadily over the past 60 years. The highlights of the more recent research include the following: (1) the complete nucleotide sequence of the genome of three strains of CMV has been determined, as well as nucleotide sequences of individual RNAs of eight other CMV strains, (2) the CMV replicase has been purified to homogeneity, and it functions in vitro to synthesize CMV RNA de novo , (3) infectious transcripts have been synthesized from full-length cDNA clones of the three strains of CMV, (4) these biologically active cDNAs are being used to map sequences involved in replication, movement, pathogenesis, resistance, and vector transmission. Biologically active cDNA clones of the satellite RNAs of CMV have been produced in seven laboratories and sequences involved in replication and pathogenicity have/are being identified, (5) finally, transgenic plants have been produced expressing either the CMV coat protein gene or satellite RNA sequences that show to protect such plants from infection by CMV. This chapter, while focusing on the more recent developments in CMV biology and biochemistry, also covers some of the same ground albeit in brief. The chapter presents a comprehensive review that can be used as a reference work for general virologists and plant pathologists, as well as those specializing in the molecular biology of CMV and/or other multicomponent plant viruses.

Factor stimulating transcription by RNA polymerase.

Abstract: A protein component usually associated with RNA polymerase can be separated from the enzyme by chromatography on phosphocellulose. The polymerase is unable to transcribe T4 DNA unless this factor is added back.

RNA complementary to a herpesvirus alpha gene mRNA is prominent in latently infected neurons.

Abstract: In initial attempts to define the molecular events responsible for the latent state of herpes simplex virus, in situ hybridization was utilized to search for virally encoded RNA transcripts in latently infected sensory neurons. The use of cloned probes representing the entire viral genome indicated that transcripts encoded within terminal repeats were present. When the alpha genes encoding ICP-0, ICP-4, and ICP-27 and the gamma 1 gene encoding VP-5 were employed, only RNA transcripts hybridizing to the ICP-0 probe were detected. In latently infected cells, the ICP-0--related transcripts were localized principally in the nucleus; this was not the case in acutely (productively) infected neurons or in neurons probed for RNA transcripts coding for actin. In Northern blotting experiments, an RNA of 2.6 kilobases was detected with the ICP-0 probe. When single-stranded DNAs from the ICP-0 region were used as probes, RNA from the strand complementary to that encoding ICP-0 messenger RNA (mRNA) was the major species detected. This RNA species may play a significant role in maintaining the latent infection.

Structural basis for inhibition of the RNA-dependent RNA polymerase from SARS-CoV-2 by remdesivir.

Abstract: The pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a global crisis. Replication of SARS-CoV-2 requires the viral RNA-dependent RNA polymerase (RdRp) enzyme, a target of the antiviral drug remdesivir. Here we report the cryo-electron microscopy structure of the SARS-CoV-2 RdRp, both in the apo form at 2.8-angstrom resolution and in complex with a 50-base template-primer RNA and remdesivir at 2.5-angstrom resolution. The complex structure reveals that the partial double-stranded RNA template is inserted into the central channel of the RdRp, where remdesivir is covalently incorporated into the primer strand at the first replicated base pair, and terminates chain elongation. Our structures provide insights into the mechanism of viral RNA replication and a rational template for drug design to combat the viral infection.