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.

Catalytic activity of an RNA molecule prepared by transcription in vitro

Abstract: Ribonuclease P is a ribonucleoprotein that cleaves precursors to transfer RNA (tRNA) molecules to yield the correct 5' terminal sequences of the mature tRNA's. The RNA moiety M1 RNA of ribonuclease P from Escherichia coli and the unprocessed transcript prepared in vitro of the gene for M1 RNA can both perform the cleavage reactions of the canonical enzyme in the absence of the protein moiety. When the transcript of the M1 RNA gene is combined with the protein moiety not only is a tRNA precursor cleaved but also the precursor to 4.5S RNA from Escherichia coli.

SARS-coronavirus replication/transcription complexes are membrane-protected and need a host factor for activity in vitro.

Abstract: SARS-coronavirus (SARS-CoV) replication and transcription are mediated by a replication/transcription complex (RTC) of which virus-encoded, non-structural proteins (nsps) are the primary constituents. The 16 SARS-CoV nsps are produced by autoprocessing of two large precursor polyproteins. The RTC is believed to be associated with characteristic virus-induced double-membrane structures in the cytoplasm of SARS-CoV-infected cells. To investigate the link between these structures and viral RNA synthesis, and to dissect RTC organization and function, we isolated active RTCs from infected cells and used them to develop the first robust assay for their in vitro activity. The synthesis of genomic RNA and all eight subgenomic mRNAs was faithfully reproduced by the RTC in this in vitro system. Mainly positive-strand RNAs were synthesized and protein synthesis was not required for RTC activity in vitro. All RTC activity, enzymatic and putative membrane-spanning nsps, and viral RNA cosedimented with heavy membrane structures. Furthermore, the pelleted RTC required the addition of a cytoplasmic host factor for reconstitution of its in vitro activity. Newly synthesized subgenomic RNA appeared to be released, while genomic RNA remained predominantly associated with the RTC-containing fraction. RTC activity was destroyed by detergent treatment, suggesting an important role for membranes. The RTC appeared to be protected by membranes, as newly synthesized viral RNA and several replicase/transcriptase subunits were protease- and nuclease-resistant and became susceptible to degradation only upon addition of a non-ionic detergent. Our data establish a vital functional dependence of SARS-CoV RNA synthesis on virus-induced membrane structures.

SARS-CoV-2 RNA dependent RNA polymerase (RdRp) targeting: an in silico perspective.

Abstract: New treatment against SARS-CoV-2 now is a must. Nowadays, the world encounters a huge health crisis by the COVID-19 viral infection. Nucleotide inhibitors gave a lot of promising results in terms of its efficacy against different viral infections. In this work, molecular modeling, docking, and dynamics simulations are used to build a model for the viral protein RNA-dependent RNA polymerase (RdRp) and test its binding affinity to some clinically approved drugs and drug candidates. Molecular dynamics is used to equilibrate the system upon binding calculations to ensure the successful reproduction of previous results, to include the dynamics of the RdRp, and to understand how it affects the binding. The results show the effectiveness of Sofosbuvir, Ribavirin, Galidesivir, Remdesivir, Favipiravir, Cefuroxime, Tenofovir, and Hydroxychloroquine, in binding to SARS-CoV-2 RdRp. Additionally, Setrobuvir, YAK, and IDX-184, show better results, while four novel IDX-184 derivatives show promising results in attaching to the SARS-CoV-2 RdRp. There is an urgent need to specify drugs that can selectively bind and subsequently inhibit SARS-CoV-2 proteins. The availability of a punch of FDA-approved anti-viral drugs can help us in this mission, aiming to reduce the danger of COVID-19. The compounds 2 and 3 may tightly bind to the SARS-CoV-2 RdRp and so may be successful in the treatment of COVID-19.