The mechanism of RNA capping by SARS-CoV-2.

ABSTRACT: The RNA genome of SARS-CoV-2 contains a 5' cap that facilitates the translation of viral proteins, protection from exonucleases and evasion of the host immune response^1-4. How this cap is made in SARS-CoV-2 is not completely understood. Here we reconstitute the N7- and 2'-O-methylated SARS-CoV-2 RNA cap (^7MeGpppA_2'-O-Me) using virally encoded non-structural proteins (nsps). We show that the kinase-like nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain⁵ of nsp12 transfers the RNA to the amino terminus of nsp9, forming a covalent RNA-protein intermediate (a process termed RNAylation). Subsequently, the NiRAN domain transfers the RNA to GDP, forming the core cap structure GpppA-RNA. The nsp14⁶ and nsp16⁷ methyltra

SUBMITTER: Park GJ 

PROVIDER: S-EPMC9492545 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature