对于UvrD家族螺旋体的二极化和激活的结构基础
Ankita Chadda1, Binh Nguyen1, Timothy M Lohman1
1Department of Biochemistry and Molecular Biophysics, Washington University in Saint Louis School of Medicine, Saint Louis, MO 63110.
bioRxiv : the preprint server for biology
|September 16, 2024
概括
二元UvrD1酶的第一个结构揭示了二元化如何激活DNA解. 这种激活涉及重新定位2B子域以防止自身抑制,这是DNA修复和复制蛋白的关键机制.
科学领域:
- 分子生物学分子生物学
- 结构生物学 结构生物学
- 生物化学 生物化学
背景情况:
- UvrD家族的酶是参与DNA复制,重组,修复和转录的必需运动蛋白.
- 这些酶沿着单链DNA作为单分子转移,但需要二元化才能进行DNA解活动.
- 之前的结构研究缺乏对UvrD螺旋酶的二维状态的洞察力.
研究的目的:
- 确定一个二面性UvrD家族化酶,Mycobacterium结核病UvrD1.1.的第一个结构.
- 通过二元化和DNA结合阐明UvrD1激活的结构基础.
- 了解2B子域在UvrD酶函数中的调控作用.
主要方法:
- 采用X射线晶体学,获得了apo UvrD1二元体和DNA结合的UvrD1二元体的结构.
- 对UvrD1的单体和二元形式的结构分析,包括与DNA结节结合.
- 进行了生化实验,以确认大肠杆菌UvrD.中的二度化接口.
主要成果:
- 确定了第一个二维UvrD1的结构,自由且与DNA结节结合.
- 分化通过2B子域发生,在DNA结合状态中具有不同的构造.
- Apo UvrD1二元体表现出对称的紧型和延伸型,表明灵活性.
- 不活跃的单体UvrD1显示了抑制的2B亚域-DNA接触,通过二分化来缓解.
结论:
- 由2B子域重定向介导的UvrD1的二元化,对于缓解自身抑制和使DNA解至关重要.
- 2B子域在UvrD基酶功能中起着重要的调节作用,而不是直接DNA解.
- 这些发现为UvrD家族酶的激活机制提供了结构性见解.
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