Poliovirus RNA-dependent RNA Polymerase (3Dpol): Kinetic, Thermodynamic, and Structural Analysis of Ribonucleotide Selection
Overview
Affiliations
We have performed a kinetic and thermodynamic analysis of 3D(pol) derivatives containing substitutions in the ribose-binding pocket with ATP analogues containing correct and incorrect sugar configurations. We find that Asp-238, a residue in structural motif A that is conserved in all RNA-dependent RNA polymerases, is a key determinant of polymerase fidelity. Alterations in the position of the Asp-238 side chain destabilize the catalytically competent 3D(pol)-primer/template-NTP complex and reduce the efficiency of phosphoryl transfer. The reduction in phosphoryl transfer may be a reflection of increased mobility of other residues in motif A that are required for stabilizing the triphosphate moiety of the nucleotide substrate in the active conformation. We present a structural model to explain how Asp-238 functions to select nucleotides with a correct sugar configuration and a correct base. We propose that this mechanism is employed by all RNA-dependent RNA polymerases. We discuss the possibility that all nucleic acid polymerases with the canonical "palm"-based active site employ a similar mechanism to maximize fidelity.
Mechanism of forced-copy-choice RNA recombination by enteroviral RNA-dependent RNA polymerases.
Arnold J, Martinez A, Jain A, Liu X, Moustafa I, Cameron C bioRxiv. 2025; .
PMID: 39974949 PMC: 11839138. DOI: 10.1101/2025.02.07.637143.
Zitzmann C, Dachert C, Schmid B, van der Schaar H, van Hemert M, Perelson A PLoS Comput Biol. 2023; 19(4):e1010423.
PMID: 37014904 PMC: 10104377. DOI: 10.1371/journal.pcbi.1010423.
Bao K, Zhang X, Li D, Sun W, Sun Z, Wang J Proc Natl Acad Sci U S A. 2022; 119(50):e2203054119.
PMID: 36469786 PMC: 9897473. DOI: 10.1073/pnas.2203054119.
Zitzmann C, Dachert C, Schmid B, van der Schaar H, van Hemert M, Perelson A bioRxiv. 2022; .
PMID: 35923314 PMC: 9347285. DOI: 10.1101/2022.07.25.501353.
Inhibition of SARS-CoV-2 polymerase by nucleotide analogs from a single-molecule perspective.
Seifert M, Bera S, van Nies P, Kirchdoerfer R, Shannon A, Le T Elife. 2021; 10.
PMID: 34617885 PMC: 8497053. DOI: 10.7554/eLife.70968.