一个随机机制驱动AAA+机器ClpB中的快速基质转位
Remi Casier1, Dorit Levy1, Inbal Riven1
1Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
Nature communications
|January 21, 2026
概括
生物机器使用ATP进行机械工作. 这项研究揭示了ClpB蛋白转位中的快速,布朗式电机类机制,挑战了以前的ATP驱动过程模型.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 生物物理学的生物物理.
背景情况:
- 腺三酸盐 (ATP) 驱动分子机器,但在AAA+蛋白质中,ATP水解与机械工作的确切机制仍在争论中.
- 之前的模型表明,序列ATP水解驱动短,合的转位步骤,但缺乏直接的实时证据.
研究的目的:
- 通过 ClpB AAA+ 机器研究基质转位的实时动态.
- 阐明ATP水解驱动蛋白质转位中的机械工作的机制.
主要方法:
- 单分子Förster共振能量转移 (smFRET) 光谱法用于实时监测脂质囊泡内的基质转位.
- 进行了三色FRET实验,以分析转位的方向性和完整性.
- 实验使用不同的温度和ATP度,以及使用ATP类似物如ATPγS进行.
主要成果:
- 转位事件发生在毫秒时间尺度上,比ATP水解速率快得多.
- 转位率对温度和ATP度的依赖性很小.
- 观察到双向和不完整的转位事件,而ATP模拟ATPγS取消了快速转位和方向性.
结论:
- 这些发现支持一种快速的,随机的布朗运动类似的机制,用于ClpB中的ATP驱动的转位.
- 这挑战了合,序列ATP水解驱动转位的普遍模式.
- 这项研究重新定义了我们对ATP如何在AAA+机器中驱动机械作用的理解.
相关概念视频
Energy to Drive Translocation
2.7K
Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generally, polypeptides are unfolded by two distinct...
2.7K
Mechanical Efficiency of Real Machines
1.3K
The mechanical efficiency of a machine is a fundamental concept that describes how effectively a machine can convert input work into output work. According to this concept, the efficiency of a machine is equal to the ratio of the output work to the input work. An ideal machine, meaning a machine that has no energy losses, has an efficiency of one. This implies that the input work and the output work are equal.
However, in reality, no machine can be truly ideal, and all of them experience some...
However, in reality, no machine can be truly ideal, and all of them experience some...
1.3K
Machines
559
Machines are complex structures consisting of movable, pin-connected multi-force members that work together to transmit forces. One example of a machine is the cutting plier, which is used to cut wires by applying forces to its handles. When equal and opposite forces are exerted on the handles of the cutting plier, they cause the cutting edges to come together and apply equal and opposite reaction forces on the wire, which are greater than the applied forces.
A free-body diagram of the...
A free-body diagram of the...
559
Translocation of Proteins into the Mitochondria
12.4K
Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...
12.4K
Cotranslational Protein Translocation
9.7K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
9.7K
Machines: Problem Solving II
650
Machines are complex structures consisting of movable, pin-connected multi-force members that work together to transmit forces. Consider a lifting tong carrying a 100 kg load. It comprises movable sections DAF and CBG linked together with member AB.
650


