The m(6)A methylation perturbs the Hoogsteen pairing-guided incorporation of an oxidized nucleotide.
The m(6)A methylation perturbs the Hoogsteen pairing-guided incorporation of an oxidized nucleotide.
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m(6)A 甲基化扰乱了 Hoogsteen 配对引导的氧化核苷酸的掺入
DOI：
10.1039/c7sc02340e
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发表时间：
2017-09-01
期刊：
影响因子：
8.4
通讯作者：
Zhou X
中科院分区：
文献类型：
--
作者：
Wang S;Song Y;Wang Y;Li X;Fu B;Liu Y;Wang J;Wei L;Tian T;Zhou X
这项研究描述了m6A在减少DNA中氧化核苷酸掺入方面的结构含义和性质。天然的核酸碱基可以形成Watson-Crick(WC)或Hoogsteen(HG)碱基对。重要的是，DNA中的8-氧代-2‘-脱氧鸟苷(8-oxo-DG)或8-氧代-DG 5’-三磷酸(8-oxo-dGTP)由于脱氧核糖环的O8和O4‘之间的空间排斥作用而有利于SYN构象。8-oxo-dGTP可以与模板腺嘌呤(A)相反地以HG配对的方式结合到DNA中。RNA和DNA都可以在A的N6位甲基化，形成N-6-甲基腺嘌呤(M6A)。已经发现，某些病毒感染可能会引起8-oxo-dGTP和m6A的产生增加。本研究旨在系统地探讨m6A甲基化对HG碱基对的影响以及由此引起的核苷酸掺入。我们的热力学熔融研究表明，在DNA双链配对区，m6A·8-oxo-dg碱基对的稳定性明显低于A·8-oxo-dG碱基对。此外，我们使用稳态前动力学方法研究了多种逆转录酶和DNA聚合酶(如人类免疫缺陷病毒1型RT和人DNA Pollβ)与m6A相对的8-oxo-dGTP的掺入。结果表明，与m6A相对，这些酶与8-oxo-dGTP的结合效率均低于A。考虑到8-oxo-dG和A之间的嘌呤-嘌呤对的立体结构，m6A的甲基化可能在很大程度上影响HG的配对。因此，将8-oxo-dGTP掺入到与m6A相反的生长链中将是不利的。此外，8-oxo-dGTP与m6A相反的受阻掺入已扩展到确定人rRNA中预定位置的m6A。我们的研究可能会对m6A在降低细胞内8-oxo-dGTP的诱变潜力方面的作用提供新的见解。
This study describes the structural implications and properties of m6A in reducing the incorporation of an oxidized nucleotide into DNA. Natural nucleic acid bases can form Watson–Crick (WC) or Hoogsteen (HG) base pairs. Importantly, 8-oxo-2′-deoxyguanosine (8-oxo-dG) in DNA or 8-oxo-dG 5′-triphosphate (8-oxo-dGTP) favors a syn conformation because of the steric repulsion between O8 and O4′ of the deoxyribose ring. 8-oxo-dGTP can be incorporated into DNA opposite the templating adenine (A) using HG pairing as the dominant mechanism. Both RNA and DNA can be methylated at the N6 position of A to form N 6-methyladenine (m6A). It has been found that certain viral infections may trigger an increase in the production of both 8-oxo-dGTP and m6A. The current study aims to systematically explore the effects of m6A methylation on HG base pairs and the consequent nucleotide incorporation. Our thermodynamic melting study shows that the m6A·8-oxo-dG is significantly less stable than the A·8-oxo-dG base pair in the paired region of a DNA duplex. Moreover, we have used pre-steady-state kinetics to examine the incorporation of 8-oxo-dGTP opposite m6A relative to A by a variety of reverse transcriptase (RT) enzymes and DNA polymerase (DNA pol) enzymes such as the human immunodeficiency virus type 1 (HIV-1) RT and human DNA pol β. The results demonstrate that all of these enzymes incorporate 8-oxo-dGTP less efficiently opposite m6A relative to A. Considering the steric bulk of the purine–purine pair between 8-oxo-dG and A, m6A methylation may affect the HG pairing to a great extent. Hence, it will be unfavorable to incorporate 8-oxo-dGTP into the growing strand opposite m6A. Moreover, the impeded incorporation of 8-oxo-dGTP opposite m6A has been extended to determine m6A at pre-defined positions in human rRNA. Our study may provide new insights into the roles of m6A in reducing the mutagenic potential of cellular 8-oxo-dGTP.
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影响因子：
64.5
作者：
Fu Y;Luo GZ;Chen K;Deng X;Yu M;Han D;Hao Z;Liu J;Lu X;Dore LC;Weng X;Ji Q;Mets L;He C
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影响因子：
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作者：
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影响因子：
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Richards NG
影响因子：
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影响因子：
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作者：
Leontis, NB;Stombaugh, J;Westhof, E
通讯作者：
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