Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Dr David Dulin, Vrije Universiteit Amsterdam
Professor Achillefs Kapanidi
Abstract
The SARS-CoV-2 pandemic caused millions of deaths worldwide, largely due to the initial lack of effective therapeutics. Vaccines and antivirals were developed rapidly, but the virus’s ability to evolve highlights the need for additional drugs. The coronavirus replication-transcription complex (RTC), a large conserved multiprotein machine that synthesizes all viral RNA, is the main antiviral target. A key class of inhibitors are nucleotide analogs (e.g., remdesivir, molnupiravir), which alter viral replication and genome integrity.
The RTC is constituted of a core, i.e. nsp12 polymerase in complex with nsp7 and nsp8 cofactors, that associates with other proteins, such as nsp13 helicase and nsp14 exonuclease. Cryo-EM has revealed high-resolution structures of various RTC complexes, but their functional characterization remains limited. To address this, my lab has developed a high-throughput magnetic tweezers assay to track RTC assembly and RNA synthesis dynamics at near single-base and millisecond resolution.
In this presentation, I will discuss our recent findings on RTC assembly into an elongation-competent complex, the roles of nsp13 and nsp14, and their impact on the mechanisms of action of nucleotide analogs. I will also outline future directions to better understand coronavirus replication and transcription regulation.