{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"bioRxiv"}],"indexed":{"date-parts":[[2026,9,26]],"date-time":"2026-09-26T13:03:52Z","timestamp":1790427832725,"version":"4.1.0"},"posted":{"date-parts":[[2021,4,4]]},"group-title":"Biochemistry","reference-count":46,"publisher":"openRxiv","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2021,4,4]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:p>High-fidelity replication of the large RNA genome of coronaviruses (CoVs) is mediated by a 3\u2032-to-5\u2032 exoribonuclease (ExoN) in non-structural protein 14 (nsp14), which excises nucleotides including antiviral drugs mis-incorporated by the low-fidelity viral RNA-dependent RNA polymerase (RdRp) and has also been implicated in viral RNA recombination and resistance to innate immunity. Here we determined a 1.6-\u00c5 resolution crystal structure of SARS-CoV-2 ExoN in complex with its essential co-factor, nsp10. The structure shows a highly basic and concave surface flanking the active site, comprising several Lys residues of nsp14 and the N-terminal amino group of nsp10. Modeling suggests that this basic patch binds to the template strand of double-stranded RNA substrates to position the 3\u2032 end of the nascent strand in the ExoN active site, which is corroborated by mutational and computational analyses. Molecular dynamics simulations further show remarkable flexibility of multi-domain nsp14 and suggest that nsp10 stabilizes ExoN for substrate RNA-binding to support its exoribonuclease activity. Our high-resolution structure of the SARS-CoV-2 ExoN-nsp10 complex serves as a platform for future development of anti-coronaviral drugs or strategies to attenuate the viral virulence.<\/jats:p>","DOI":"10.1101\/2021.04.02.438274","type":"posted-content","created":{"date-parts":[[2021,4,4]],"date-time":"2021-04-04T18:25:12Z","timestamp":1617560712000},"source":"Crossref","is-referenced-by-count":15,"title":["Structure and dynamics of SARS-CoV-2 proofreading exoribonuclease ExoN"],"prefix":"10.64898","author":[{"given":"Nicholas H.","family":"Moeller","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ke","family":"Shi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"\u00d6zlem","family":"Demir","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Surajit","family":"Banerjee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lulu","family":"Yin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher","family":"Belica","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cameron","family":"Durfee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rommie E.","family":"Amaro","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hideki","family":"Aihara","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"54368","reference":[{"issue":"7819","key":"2021040704000836000_2021.04.02.438274v1.1","doi-asserted-by":"crossref","first-page":"154","DOI":"10.1038\/s41586-020-2368-8","article-title":"Structure of replicating SARS-CoV-2 polymerase","volume":"584","year":"2020","journal-title":"Nature"},{"key":"2021040704000836000_2021.04.02.438274v1.2","doi-asserted-by":"publisher","DOI":"10.1016\/j.virusres.2017.01.023"},{"issue":"1","key":"2021040704000836000_2021.04.02.438274v1.3","doi-asserted-by":"crossref","first-page":"265","DOI":"10.1146\/annurev-virology-100114-055218","article-title":"Continuous and Discontinuous RNA Synthesis in Coronaviruses","volume":"2","year":"2015","journal-title":"Annu Rev Virol"},{"key":"2021040704000836000_2021.04.02.438274v1.4","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.96.24.13910"},{"key":"2021040704000836000_2021.04.02.438274v1.5","doi-asserted-by":"publisher","DOI":"10.1007\/s00239-001-0064-3"},{"key":"2021040704000836000_2021.04.02.438274v1.6","doi-asserted-by":"publisher","DOI":"10.1128\/JVI.00694-10"},{"key":"2021040704000836000_2021.04.02.438274v1.7","doi-asserted-by":"publisher","DOI":"10.4161\/rna.8.2.15013"},{"key":"2021040704000836000_2021.04.02.438274v1.8","doi-asserted-by":"publisher","DOI":"10.1016\/j.virusres.2006.01.017"},{"key":"2021040704000836000_2021.04.02.438274v1.9","doi-asserted-by":"publisher","DOI":"10.1038\/s41467-020-18463-z"},{"key":"2021040704000836000_2021.04.02.438274v1.10","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.0508200103"},{"key":"2021040704000836000_2021.04.02.438274v1.11","doi-asserted-by":"publisher","DOI":"10.1016\/j.molcel.2020.07.027"},{"key":"2021040704000836000_2021.04.02.438274v1.12","doi-asserted-by":"crossref","unstructured":"Smith EC & Denison MR (2013 Coronaviruses as DNA wannabes: a new model for the regulation of RNA virus replication fidelity. 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