Mn2+ coordinates Cap-0-RNA to align substrates for efficient 2'-O-methyl transfer by SARS-CoV-2 nsp16.

ABSTRACT: Capping of viral messenger RNAs is essential for efficient translation, for virus replication, and for preventing detection by the host cell innate response system. The SARS-CoV-2 genome encodes the 2'-O-methyltransferase nsp16, which, when bound to the coactivator nsp10, uses S-adenosylmethionine (SAM) as a donor to transfer a methyl group to the first ribonucleotide of the mRNA in the final step of viral mRNA capping. Here, we provide biochemical and structural evidence that this reaction requires divalent cations, preferably Mn2+, and a coronavirus-specific four-residue insert. We determined the x-ray structures of the SARS-CoV-2 2'-O-methyltransferase (the nsp16-nsp10 heterodimer) in complex with its reaction substrates, products, and divalent metal cations. These structural snapshots

SUBMITTER: Minasov G 

PROVIDER: S-EPMC8432954 | biostudies-literature | 2021 Jun

REPOSITORIES: biostudies-literature