오준택 (경희대학교, UCSD)

한빛사논문

조회201

경희대학교, UCSD

CV File 68 kb

J. Am. Chem. Soc., Mar 06 2024, 146 (9) | https://doi.org/10.1021/jacs.3c14476 Molecular Mechanism of RNA Polymerase II Transcriptional Mutagenesis by the Epimerizable DNA Lesion, Fapy·dG

Shijun Gao ¹, Peini Hou ², Juntaek Oh ^2,3, Dong Wang^2,4,5, Marc M Greenberg¹

¹Department of Chemistry, Johns Hopkins University, 3400 N. Charles Street, Baltimore, Maryland 21218, United States.

²Division of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, California 92093, United States.

³Department of Regulatory Science, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea.

⁴Department of Cellular and Molecular Medicine, School of Medicine, University of California, San Diego, La Jolla, California 92093, United States.

⁵Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States.

^#S.G., P.H., and J.O. contributed equally to this research.

Corresponding Authors : Dong Wang, Marc M. Greenberg

Abstract

Oxidative DNA lesions cause significant detrimental effects on a living species. Two major DNA lesions resulting from dG oxidation, 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OxodGuo) and formamidopyrimidine (Fapy·dG), are produced from a common chemical intermediate. Fapy·dG is formed in comparable yields under oxygen-deficient conditions. Replicative bypass of Fapy·dG in human cells is more mutagenic than that of 8-OxodGuo. Despite the biological importance of transcriptional mutagenesis, there are no reports of the effects of Fapy·dG on RNA polymerase II (Pol II) activity. Here we perform comprehensive kinetic studies to investigate the impact of Fapy·dG on three key transcriptional fidelity checkpoint steps by Pol II: insertion, extension, and proofreading steps. The ratios of error-free versus error-prone incorporation opposite Fapy·dG are significantly reduced in comparison with undamaged dG. Similarly, Fapy·dG:A mispair is extended with comparable efficiency as that of the error-free, Fapy·dG:C base pair. The α- and β-configurational isomers of Fapy·dG have distinct effects on Pol II insertion and extension. Pol II can preferentially cleave error-prone products by proofreading. To further understand the structural basis of transcription processing of Fapy·dG, five different structures were solved, including Fapy·dG template-loading state (apo), error-free cytidine triphosphate (CTP) binding state (prechemistry), error-prone ATP binding state (prechemistry), error-free Fapy·dG:C product state (postchemistry), and error-prone Fapy·dG:A product state (postchemistry), revealing distinctive nucleotide binding and product states. Taken together, our study provides a comprehensive mechanistic framework for better understanding how Fapy·dG lesions impact transcription and subsequent pathological consequences.

논문정보

형식Research article
게재일2024년 03월 (BRIC 등록일 2024-04-25)
연구진국내+국외 연구진
분야 생명과학 > 구조생물 및 생물물리학

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