连锁的 MutS 和 MutL 滑动可以控制 DNA 扩散以激活不匹配修复
Jiaquan Liu1, Jeungphill Hanne1, Brooke M Britton1
1Department of Cancer Biology and Genetics, The Ohio State University Wexner Medical Center, Columbus, Ohio 43210, USA.
Nature
|November 17, 2016
概括
DNA不匹配修复蛋白 MutS 和 MutL 在DNA上形成稳定的滑动. 这种机制促进了 MutH 内核酶的招募,使得有效的 DNA 修复和突出序列组装成为可能.
科学领域:
- 分子生物学
- 遗传学
- 生物化学
背景情况:
- DNA不匹配是由于复制,重组或DNA损伤过程中的错误引起的.
- MutS (MSH) 和MutL (MLH/PMS) 蛋白质在不匹配修复 (MMR) 和DNA损伤传感中得到保护.
- 在MMR基因的缺陷与林奇综合征和各种癌症有关.
研究的目的:
- 阐明 MutS 和 MutL 蛋白在 DNA 不匹配修复中的协作机制.
- 在修复过程中可视化MMR蛋白的动态相互作用.
- 了解MMR蛋白质复合体如何在DNA上组装和调节.
主要方法:
- 组合可视化技术观察大肠杆菌 (Ec) 的DNA不匹配修复.
- 生物化学测试用于研究蛋白质-DNA相互作用和复合物形成.
- 对依赖ATP的形成和扩散动态的分析.
主要成果:
- EcMutS识别了不匹配,形成稳定的ATP结合的滑动,沿着DNA扩散.
- 通过 EcMutS ,EcMutL 创建了一个追踪 DNA 骨干的搜索复合体.
- 通过EcMutL的ATP结合形成了第二个,促进了EcMutH内核酶的结合,并增加了1000倍以上的DNA关联.
结论:
- MutS和MutL蛋白质的稳定滑动的顺序形成对于有效的DNA不匹配修复至关重要.
- MutS-MutL-MutH复合体的动态组合调节一个维度的扩散,以精确地定位修复.
- 了解这些机制可以了解基因组稳定性和癌症预防.
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