通过AAA+ ATPase介导的RuvAB-Holliday结枝迁移的机制
Jiri Wald1,2,3,4,5, Dirk Fahrenkamp6,7,8, Nikolaus Goessweiner-Mohr9,10,11,12,13,14
1Institute of Structural and Systems Biology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. jiri.wald@cssb-hamburg.de.
Nature
|August 24, 2022
概括
研究人员通过研究RuvAB复合体来阐明DNA重组的机制. 时间解析的冷EM结构揭示了RuvB电机如何使用ATP水解来驱动DNA修复过程中的分支迁移.
科学领域:
- 分子生物学
- 结构生物学
- 生物化学
背景情况:
- 在所有生命形式的DNA重组中,
- 在细菌中,由RuvA和两个RuvB电机组成的RuvAB复合体处理霍利代结以实现链交换.
- 在此之前,RuvAB介导的分支迁移的精确结构和机制是未知的.
研究的目的:
- 在霍利代结处理过程中确定RuvAB复合物的结构和机制.
- 阐明ATP水解,核酸交换和RuvB的结构变化之间的时空关系.
- 了解RuvAB复合物如何促进DNA重组的分支迁移.
主要方法:
- 使用时间分辨率冷电子显微镜 (cryo-EM) 来捕捉RuvAB复合物的结构.
- 在霍利德连接组装和处理过程中,在七个不同的形状状态中获得了结构.
- 分析的重点是核酸循环和RuvB六基体内的协调运动.
主要成果:
- 解析了ATP-水解RuvAB复合物的七个不同的结构,详细说明了完整的核酸循环.
- 在RuvB的"转换器"区域中发现了协调的运动,刺激ATP水解和核酸交换.
- RuvB被证明可以将ATP能量转化为杆运动,产生分支迁移的力,电机沿着DNA基板旋转.
结论:
- 这项研究解读了RuvAB复合体对同类重组的分子原理.
- 在AAA+电机中阐明了化学机械合的离散过渡状态中间体.
- 这些发现为设计AAA+发动机的向化合物提供了蓝图.
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