RNA synthesis initiation and termination by the non-segmented negative-strand RNA virus polymerases
Embargo Date
2027-03-18
OA Version
Citation
Abstract
Non-segmented negative-strand RNA viruses (nsNSVs) make up an order of viruses that range in prevalence and severity. For example, respiratory syncytial virus (RSV) causes respiratory tract infections and countless hospitalizations annually, while Ebola virus (EBOV) causes hemorrhagic fever which is less widespread but more deadly. A key commonality of the nsNSVs is their RNA-dependent RNA polymerase that can replicate and transcribe their genome. These viral polymerases (L) have five domains that are each responsible for different functions and need to coordinate with each other and other cellular and viral factors for RNA synthesis. Due to the essential nature of this enzyme, it is an attractive candidate for antiviral research. We sought to further study the polymerase and identify aspects that are important for different stages of RNA synthesis. The priming loop of the polymerase has been recognized to be involved in many different facets of polymerase function. Here, we identified priming residues that are involved in RSV initiation and characterized a non-nucleoside inhibitor that impedes the conformation changes necessary for the RSV polymerase priming loop to transition from initiation into elongation mode. In addition, mutation of a separate residue of the priming loop caused changes in mRNA polyadenylation. Besides the priming loop, we identified another region of the polymerase, the template exit channel, that contains essential residues for transcription termination/ mRNA release. Finally, we studied a cellular protein for involvement during mRNA transcription/ polyadenylation but did not find any conclusive evidence. The work in this dissertation widens our understanding of the polymerase and necessary interactions for RNA synthesis, which could be key targets for therapeutic design.
Description
2024
License
Attribution-NonCommercial-NoDerivatives 4.0 International