用人类DNA聚合酶β进行Fapy•dG复制的生物化学和结构特征
Shijun Gao1, Peyton N Oden2, Benjamin J Ryan2
1Department of Chemistry, Johns Hopkins University, 3400 N. Charles St., Baltimore, MD 21218, USA.
Nucleic acids research
|April 18, 2024
概括
突变性DNA损伤Fapy•dG导致G→T和G→A突变. DNA聚合酶β (Pol β) 绕过Fapy•dG,导致突变,而不是结合Fapy•dGTP,澄清Fapy•dGG.
科学领域:
- 在DNA损伤和修复过程中.
- 分子毒理学分子毒理学
- 生物化学 生物化学
背景情况:
- N6-(2-deoxy-α,β-d-erythro-pentofuranosyl)-2,6-diamino-4-hydroxy-5-formamido-pyrimidine (Fapy•dG) 是一种突变性DNA损伤. 这是一种突变性DNA损伤.
- Fapy•dG与8-oxo-7,8-dihydro-2'-deoxyguanosine (8-OxodGuo) 相比形成,并导致G → T转换和G → A转换.
- 通过DNA聚合酶处理Fapy•dG的机制尚不清楚.
研究的目的:
- 调查DNA聚合酶β (Pol β) 如何绕过一个模板Fapy•dG.
- 确定Fapy•dGTP从Fapy•dG在原始终端插入或延伸是否有助于变异性.
- 阐明Fapy•dG突变性分子的基础.
主要方法:
- 使用DNA聚合酶β (Pol β) 的体外生化分析.
- 核酸合并和原料扩展的动态分析.
- 局部定向突变发生,以评估聚合酶活性.
主要成果:
- 与dCMP或dAMP相比,Pol β显示TMP在模板Fapy•dG相反的组合中是低效的.
- Fapy•dGTP是一种较差的基质,与dC相比,在dA相对面更有效地结合起来.
- 从Fapy•dG在原始3'-终端的延伸是低效的,因为对催化剂的位置不佳.
结论:
- 通过DNA聚合酶对Fapy•dG的突变性绕道,而不是Fapy•dGTP的结合,是Fapy•dG突变性作用的可能来源.
- 这些发现有助于更好地了解Fapy•dG.的突变性潜力.
- 这项研究阐明了Pol β在处理Fapy•dG病变中的作用.
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