通过冷电子显微镜捕获的GroEL的ATP结合状态
N A Ranson1, G W Farr, A M Roseman
1Department of Crystallography, Birkbeck College London, Malet Street, London WC1E 7HX, United Kingdom. n.ranson@bbk.ac.uk
Cell
|January 10, 2002
概括
沙佩罗宁GroEL蛋白折叠周期涉及合作性ATP结合,激活一个环折叠,而另一个环释放基质. 结构洞察力揭示了域移动和盐桥变化,这些变化对这个过程和分子机器合作性至关重要.
科学领域:
- 生物化学 生物化学
- 结构生物学 结构生物学
- 分子机器分子机器
背景情况:
- 沙佩罗宁GroEL通过一种循环过程促进蛋白质折叠,其中包括ATP结合和水解.
- GroEL 作为一个双环复合体运作,每个环能够结合ATP和基质.
- 了解GroEL的合作功能机制是理解蛋白质平衡的关键.
研究的目的:
- 为了阐明护卫者GroEL的蛋白质折叠周期的结构基础.
- 调查ATP结合在GroEL的结构变化和合作性中的作用.
- 开发解释ATP诱导的基质释放和环间合作性的结构模型.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定GroEL-ATP复合物的结构.
- 原子结构与冷电磁密度图相匹配.
- 对与GroEL和GroEL-GroES-ADP复合体结合的ATP结构变化的分析.
主要成果:
- GroEL-ATP结构显示了中间域的向下旋转.
- 观察到从基质切换到ATP结合域的跨子单元盐桥接触.
- 结构数据表明在ATP结合时降低多亲和力和合作性的模型.
结论:
- 这项研究为GroEL.中ATP诱导的形状变化提供了一个结构机制.
- 建议GroEL的合作模式,包括盐桥切换.
- 这些发现为其他环形分子机器的合作提供了洞察力.
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