单分子FRET探测AAA+机器的蛋白转位孔环对蛋白转位孔环的影响
Marija Iljina1, Hisham Mazal1, Ashan Dayananda2
1Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
Biophysical journal
|January 10, 2024
概括
在AAA+蛋白ClpBB中.
科学领域:
- 蛋白质动力学 蛋白质动力学
- 分子机器是分子机器.
- 生物化学 生物化学
背景情况:
- AAA+ 蛋白质是各种细胞过程中必不可少的分子机器.
- ClpB是一种AAA+蛋白质,可以分解蛋白质,具有灵活的孔环.
- 在基质转位中,ClpB的孔环的作用仍然不清楚.
研究的目的:
- 为了研究ClpB的孔环和核酸结合域之间的全性合.
- 确定ATP水解如何影响孔环动力学和基质转位.
主要方法:
- 单分子福斯特共振能量转移 (smFRET) 光谱仪用于测量孔环动态.
- 在核酸结合域中的Walker B基因的位点导向突变发生,以解离ATP水解.
- 分子动力学模拟以表征构造动力学和全性路径.
主要成果:
- 孔环动力学受到ClpB域的核酸结合状态的显著调整.
- 核酸水解的化效应是远程的,对孔环产生不同影响.
- 保存的PL3孔环表现出明显的形状偏好,这取决于NBD1中的ATP水解与NBD2.
结论:
- 孔环不是被动的,而是基质转移的积极参与者.
- 在AAA+蛋白中的ATP水解会诱导孔环中的远程全形状变化.
- 这些依赖ATP的孔环动态对于ClpB和类似的分子机器的功能至关重要.
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