人类DNA聚合酶β的Fapy•dG复制的生物化学和结构特征
bioRxiv : the preprint server for biology
|January 31, 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,但由Fapy•dG在原始终端的低效延伸,而不是Fapy•dGTP的结合,驱动其突变效应.
科学领域:
- 分子生物学分子生物学
- 修复DNA修复DNA的修复
- 化学生物学 化学生物学
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,并诱导G→T转换和G→A转换.
研究的目的:
- 研究Fapy•dG突变发生背后的分子机制.
- 确定DNA聚合酶β (Pol β) 在DNA复制和修复过程中如何处理Fapy•dG.
主要方法:
- 评估了Pol β绕过模板Fapy•dG.G.的能力.
- 确定了Fapy•dGTP与不同基础对立的整合效率.
- 分析了Fapy•dG.对面的初始终端的延伸效率.
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.
- 由于触媒定位不佳,从Fapy•dG在初始3'-终端的延伸是低效的.
结论:
- 模板Fapy•dG的突变性绕道,而不是Fapy•dGTP的整合,是Fapy•dG突变性作用的主要来源.
- 这些发现阐明了Fapy•dG的促进性潜力及其通过DNA聚合酶的处理.
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