We report on a study that combines advanced fluorescence methods with molecular dynamics (MD) simulations to cover timescales from nanoseconds to milliseconds for a large protein. This allows us to delineate how ATP hydrolysis in a protein causes allosteric changes at a distant protein binding site, using the chaperone Hsp90 as test system. The allosteric process occurs via hierarchical dynamics involving timescales from nano- to milliseconds and length scales from Ångstroms to several nanometers. We find that hydrolysis of one ATP is coupled to a conformational change of Arg380, which in turn passes structural information via the large M-domain α-helix to the whole protein. The resulting structural asymmetry in Hsp90 leads to the collapse of a central folding substrate binding site, causing the formation of a novel collapsed state (closed state B) that we characterise structurally. We presume that similar hierarchical mechanisms are fundamental for information transfer induced by ATP hydrolysis through many other proteins.

中文翻译：

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通过单分子 FRET 测量和 MD 模拟监测 ATP 水解后变构的层次动力学

我们报告了一项研究，该研究将先进的荧光方法与分子动力学 (MD) 模拟相结合，涵盖了大型蛋白质从纳秒到毫秒的时间尺度。这使我们能够使用分子伴侣 Hsp90 作为测试系统来描述蛋白质中的 ATP 水解如何引起远处蛋白质结合位点的变构变化。变构过程通过层次动力学发生，涉及从纳到毫秒的时间尺度和从埃到几纳米的长度尺度。我们发现一种 ATP 的水解与 Arg380 的构象变化相结合，而 Arg380 的构象变化又通过大的 M 结构域 α 螺旋将结构信息传递给整个蛋白质。Hsp90 中由此产生的结构不对称性导致中心折叠底物结合位点的塌陷，导致形成我们在结构上表征的新型塌陷状态（闭合状态 B）。我们推测类似的分层机制是 ATP 水解通过许多其他蛋白质诱导的信息传递的基础。