RNA聚合酶驱动大肠杆菌中的核糖核酸切除DNA修复
Zhitai Hao1, Manjunath Gowder2, Sergey Proshkin3
1Department of Biochemistry and Molecular Pharmacology, New York University Grossman School of Medicine, New York, NY 10016, USA.
Cell
|May 17, 2023
概括
核糖核酸切除修复 (RER) 通过核糖核酸 HII (RNaseHII) 酶与转录相结合,该酶由RNA聚合酶 (RNAP) 携带. 这种转录合RER (TC-RER) 机制有效地消除复制过程中的DNA错误.
科学领域:
- 分子生物学
- 遗传学
- 生物化学
背景情况:
- 核酶HII (RNaseHII) 对于从基因组DNA中去除核酸单酸盐 (rNMPs) 是至关重要的.
- RNaseHII活动的精确机制和细胞背景,特别是与DNA复制和转录的关系,仍然不完全理解.
研究的目的:
- 阐明核酸切除修复 (RER) 与转录的直接联系.
- 描述RNaseHII和RNA聚合酶 (RNAP) 之间的结构和功能相互作用.
- 确定转录合RER (TC-RER) 在保持基因组完整性的作用.
主要方法:
- 相关性拉下和质谱测绘蛋白质相互作用.
- 用冷电子显微镜来确定结构复合物.
- 在大肠杆菌中进行生物化学测定和遗传分析.
主要成果:
- 大多数RNaseHII与大肠杆菌中的RNAP相互作用,形成转录合RER (TC-RER) 复合体.
- 低温-EM结构显示了参与和不参与状态的特定RNAP-RNaseHII相互作用.
- 弱化的RNAP-RNaseHII相互作用在体内会损害RER,支持RNaseHII扫描DNA的模型,同时与RNAP相关.
- TC-RER占修复事件的很大一部分,突出了RNAP在错误监控中的作用.
结论:
- 通过RNAP直接与转录合,形成TC-RER复合体.
- RNAP作为RNaseHII的移动平台,促进检测和修复DNA错误.
- 通过纠正常见的复制错误,TC-RER是维持基因组稳定的重要途径.
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