Template requirements of Zika RNA polymerase during in vitro RNA synthesis from the 3′-end of virus minus-strand RNA

• Published in: Biochimie 2022-04, Vol.195, p.71-76
• Main Authors: Calmels, Christina, Métifiot, Mathieu, Andreola, Marie-Line
• Format: Article
• Language: English
• Subjects: In vitro assay; Life Sciences; Microbiology and Parasitology; RNA polymerase; Template requirement; Virology; Zika virus
• ISSN: 0300-9084; 1638-6183
• DOI: 10.1016/j.biochi.2021.11.003

As ZIKV continues to spread, many “unknowns” remain and research is needed to advance the understanding of this important pathogen. Viral RNA dependent-RNA polymerases (RdRp) are validated targets for inhibitors of the replication of several viruses. Several studies have set up in vitro enzymatic assays of the RdRp of the Zika virus for testing of candidate inhibitors. While most of these studies use short synthetic polymers, we have shown in a previous work that the Zika polymerase domain is capable of a de novo synthesis of the viral genome using the natural viral RNA as template. Here we have studied the role of the sequences at the 3′end of the minus-strand RNA in the initiation of the RNA synthesis by the Zika isolated RdRp. Our results strongly suggest that the region containing the 105 first nucleotides from the 3′ end of the minus-strand RNA is important for initiation of the positive RNA synthesis. This indicates that this region displays all the primary and secondary structures to be efficiently recognized by the recombinant RdRp in vitro. Moreover, we show that the 46 nucleotides are sufficient to initiate RNA synthesis. In addition, the ZIKV polymerase domain poorly replicated the RNA of other RNA viruses and appeared highly selective for its own RNA. •The process of Zika virus (ZIKV) replication is not well understood.•This work reports the characterization of the RNA requirements to serve as good template for the RNA synthesis initiation by ZIKV NS5-polymerase domain.•The role of the sequences at the 3′end of the minus strand RNA was studied.The region containing the first 46 nucleotides from 3′ end of the ZIKV minus strand RNA is necessary and sufficient for the initiation of the positive RNA synthesis.