The mechanism of RNA capping by SARS-CoV-2
(2022) In Nature 609(7928). p.793-800- 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 response1–4. 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 (7MeGpppA2′-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.... (More)
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 response1–4. 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 (7MeGpppA2′-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 methyltransferases then add methyl groups to form functional cap structures. Structural analyses of the replication–transcription complex bound to nsp9 identified key interactions that mediate the capping reaction. Furthermore, we demonstrate in a reverse genetics system8 that the N terminus of nsp9 and the kinase-like active-site residues in the NiRAN domain are required for successful SARS-CoV-2 replication. Collectively, our results reveal an unconventional mechanism by which SARS-CoV-2 caps its RNA genome, thus exposing a new target in the development of antivirals to treat COVID-19.
(Less)
- author
- organization
- publishing date
- 2022-09-22
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Nature
- volume
- 609
- issue
- 7928
- pages
- 8 pages
- publisher
- Nature Publishing Group
- external identifiers
-
- scopus:85138010010
- pmid:35944563
- ISSN
- 0028-0836
- DOI
- 10.1038/s41586-022-05185-z
- language
- English
- LU publication?
- yes
- id
- e340b426-1bf3-483c-bf66-4f0f7be69452
- date added to LUP
- 2022-11-30 13:17:53
- date last changed
- 2024-07-24 00:23:47
@article{e340b426-1bf3-483c-bf66-4f0f7be69452, abstract = {{<p>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<sup>1–4</sup>. 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 (<sup>7Me</sup>GpppA<sub>2′-O-Me</sub>) using virally encoded non-structural proteins (nsps). We show that the kinase-like nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain<sup>5</sup> 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 nsp14<sup>6</sup> and nsp16<sup>7</sup> methyltransferases then add methyl groups to form functional cap structures. Structural analyses of the replication–transcription complex bound to nsp9 identified key interactions that mediate the capping reaction. Furthermore, we demonstrate in a reverse genetics system<sup>8</sup> that the N terminus of nsp9 and the kinase-like active-site residues in the NiRAN domain are required for successful SARS-CoV-2 replication. Collectively, our results reveal an unconventional mechanism by which SARS-CoV-2 caps its RNA genome, thus exposing a new target in the development of antivirals to treat COVID-19.</p>}}, author = {{Park, Gina J. and Osinski, Adam and Hernandez, Genaro and Eitson, Jennifer L. and Majumdar, Abir and Tonelli, Marco and Henzler-Wildman, Katie and Pawłowski, Krzysztof and Chen, Zhe and Li, Yang and Schoggins, John W. and Tagliabracci, Vincent S.}}, issn = {{0028-0836}}, language = {{eng}}, month = {{09}}, number = {{7928}}, pages = {{793--800}}, publisher = {{Nature Publishing Group}}, series = {{Nature}}, title = {{The mechanism of RNA capping by SARS-CoV-2}}, url = {{http://dx.doi.org/10.1038/s41586-022-05185-z}}, doi = {{10.1038/s41586-022-05185-z}}, volume = {{609}}, year = {{2022}}, }