Coupling of N7-methyltransferase and 3′-5′ exoribonuclease with SARS-CoV-2 polymerase reveals mechanisms for capping and proofreading

Liming Yan, Yunxiang Yang, Mingyu Li, Ying Zhang, Litao Zheng, Ji Ge, Yucen C. Huang, Zhenyu Liu, Tao Wang, Shan Gao, Ran Zhang, Yuanyun Y. Huang, Luke W. Guddat, Yan Gao, Zihe Rao, Zhiyong Lou

Producción científica: Contribución a una revistaArtículorevisión exhaustiva

128 Citas (Scopus)

Resumen

The capping of mRNA and the proofreading play essential roles in SARS-CoV-2 replication and transcription. Here, we present the cryo-EM structure of the SARS-CoV-2 replication-transcription complex (RTC) in a form identified as Cap(0)-RTC, which couples a co-transcriptional capping complex (CCC) composed of nsp12 NiRAN, nsp9, the bifunctional nsp14 possessing an N-terminal exoribonuclease (ExoN) and a C-terminal N7-methyltransferase (N7-MTase), and nsp10 as a cofactor of nsp14. Nsp9 and nsp12 NiRAN recruit nsp10/nsp14 into the Cap(0)-RTC, forming the N7-CCC to yield cap(0) (7MeGpppA) at 5′ end of pre-mRNA. A dimeric form of Cap(0)-RTC observed by cryo-EM suggests an in trans backtracking mechanism for nsp14 ExoN to facilitate proofreading of the RNA in concert with polymerase nsp12. These results not only provide a structural basis for understanding co-transcriptional modification of SARS-CoV-2 mRNA but also shed light on how replication fidelity in SARS-CoV-2 is maintained.

Idioma originalEnglish
Páginas (desde-hasta)3474-3485.e11
PublicaciónCell
Volumen184
N.º13
DOI
EstadoPublished - jun. 24 2021
Publicado de forma externa

Nota bibliográfica

Funding Information:
This work was supported by the National Natural Science Foundation of China ( U20A20135 ), the National Program on Key Research Project of China ( 2020YFA0707500 and 2017YFC0840300 ), Tsinghua University Spring Breeze Fund ( 2020Z99CFG015 ), and the Strategic Priority Research Program of the Chinese Academy of Sciences ( XDB37030201 ).

Publisher Copyright:
© 2021 Elsevier Inc.

ASJC Scopus Subject Areas

  • General Biochemistry,Genetics and Molecular Biology

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't

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