Structural and functional insights into the enzymatic plasticity of the SARS-CoV-2 NiRAN domain.

Autor:	Small GI; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA., Fedorova O; Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA; Howard Hughes Medical Institute, Yale University, New Haven, CT 06520, USA., Olinares PDB; Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA., Chandanani J; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA., Banerjee A; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA; Tri-Institutional Program in Chemical Biology, The Rockefeller University, New York, New York, USA., Choi YJ; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA., Molina H; Proteomics Resource Center, The Rockefeller University, New York, NY 10065, USA., Chait BT; Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, USA., Darst SA; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA., Campbell EA; Laboratory of Molecular Biophysics, The Rockefeller University, 1230 York Avenue, New York, NY 10065, USA. Electronic address: campbee@rockefeller.edu.
Jazyk:	angličtina
Zdroj:	Molecular cell [Mol Cell] 2023 Nov 02; Vol. 83 (21), pp. 3921-3930.e7. Date of Electronic Publication: 2023 Oct 26.
DOI:	10.1016/j.molcel.2023.10.001
Abstrakt:	The enzymatic activity of the SARS-CoV-2 nidovirus RdRp-associated nucleotidyltransferase (NiRAN) domain is essential for viral propagation, with three distinct activities associated with modification of the nsp9 N terminus, NMPylation, RNAylation, and deRNAylation/capping via a GDP-polyribonucleotidyltransferase reaction. The latter two activities comprise an unconventional mechanism for initiating viral RNA 5' cap formation, while the role of NMPylation is unclear. The structural mechanisms for these diverse enzymatic activities have not been properly delineated. Here, we determine high-resolution cryoelectron microscopy (cryo-EM) structures of catalytic intermediates for the NMPylation and deRNAylation/capping reactions, revealing diverse nucleotide binding poses and divalent metal ion coordination sites to promote its repertoire of activities. The deRNAylation/capping structure explains why GDP is a preferred substrate for the capping reaction over GTP. Altogether, these findings enhance our understanding of the promiscuous coronaviral NiRAN domain, a therapeutic target, and provide an accurate structural platform for drug development. Competing Interests: Declaration of interests The authors declare no competing interests. (Copyright © 2023 Elsevier Inc. All rights reserved.)
Databáze:	MEDLINE
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