+検索条件
-Structure paper
タイトル | Coupling of N7-methyltransferase and 3'-5' exoribonuclease with SARS-CoV-2 polymerase reveals mechanisms for capping and proofreading. |
---|---|
ジャーナル・号・ページ | Cell, Vol. 184, Issue 13, Page 3474-3485.e11, Year 2021 |
掲載日 | 2021年6月24日 |
著者 | 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 / |
PubMed 要旨 | 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 ...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) (GpppA) 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. |
リンク | Cell / PubMed:34143953 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.35 Å |
構造データ | EMDB-31138, PDB-7egq: EMDB-31146, PDB-7eiz: |
化合物 | ChemComp-ZN: ChemComp-MG: |
由来 |
|
キーワード | VIRAL PROTEIN/RNA (ウイルス性) / SARS-CoV-2 (SARSコロナウイルス2) / Replication-Transcription Complex / nsp10 and nsp14 / VIRAL PROTEIN-RNA COMPLEX (ウイルス性) |