Abstract
Viral RNA-dependent RNA polymerases (RdRps) are a target for broad-spectrum antiviral therapeutic agents. Recently, we demonstrated that incorporation of the T-1106 triphosphate, a pyrazine-carboxamide ribonucleotide, into nascent RNA increases pausing and backtracking by the poliovirus RdRp. Here, by monitoring enterovirus A-71 RdRp dynamics during RNA synthesis using magnetic tweezers, we identify the “backtracked” state as an intermediate used by the RdRp for copy-back RNA synthesis and homologous recombination. Cell-based assays and RNA sequencing (RNA-seq) experiments further demonstrate that the pyrazine-carboxamide ribonucleotide stimulates these processes during infection. These results suggest that pyrazine-carboxamide ribonucleotides do not induce lethal mutagenesis or chain termination but function by promoting template switching and formation of defective viral genomes. We conclude that RdRp-catalyzed intra- and intermolecular template switching can be induced by pyrazine-carboxamide ribonucleotides, defining an additional mechanistic class of antiviral ribonucleotides with potential for broad-spectrum activity.
Original language | English |
---|---|
Pages (from-to) | 4467-4480.e7 |
Journal | Molecular Cell |
Volume | 81 |
Issue number | 21 |
DOIs | |
Publication status | Published - 2021 |
Bibliographical note
Accepted Author ManuscriptKeywords
- backtracking
- copy-back RNA synthesis
- enterovirus A71
- favipiravir
- poliovirus
- pyrazine-carboxamide analogue
- recombination
- RNA-dependent RNA polymerase
- T-1106
- template switching