固态核磁共振显示多药ABC载体BmrA中的非对称ATP水解
Denis Lacabanne1, Thomas Wiegand1, Margot Di Cesare2
1Physical Chemistry, ETH Zurich, 8093 Zurich, Switzerland.
Journal of the American Chemical Society
|July 1, 2022
概括
这项研究揭示了ATP在ABC输送器中如何发生水解. 研究人员使用固态核磁共振 (NMR) 发现,在水解过程中,ATP结合部位会失去对称性,但在过程结束后会恢复对称性.
科学领域:
- 生物化学
- 结构生物学
- 分子生物物理学
背景情况:
- 通过ATP结合盒 (ABC) 载体进行ATP水解的机制对于它们的功能至关重要,但仍然不完全理解.
- 在细胞过程中,包括多种药物耐药性,ABC转运体起着至关重要的作用.
研究的目的:
- 阐明多药物ABC输送器BmrA在催化周期中的构造变化和动态.
- 使用先进的NMR技术,研究BmrA的核酸结合状态 (水解前,过渡期和水解后).
主要方法:
- 使用P固态NMR光谱来探测形态动力学.
- 使用定位突变 (E504A突变) 和ATP类似物来捕获特定的催化状态.
- 分析了C NMR光谱和P-P 2D相关光谱以评估核酸结合点的对称性和动态.
主要成果:
- 在P NMR中显示出强烈的ATP结合到前水解状态的两个位点.
- 在过渡状态下,BmrA的二分体对称性被打破,其中一个位点紧密地与ADP:Mg2+:vanadate结合,另一个位点则开放.
- 后水解状态显示ADP对两个位点的结合较弱,并恢复了对称性.
结论:
- 这项研究表明BmrA在ATP水解过程中的核酸结合部位失去并随后恢复对称性.
- 这些发现为ABC载体在分子水平上的催化机制提供了关键的见解.
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