A structural change in the kinesin motor protein that drives motility
A structural change in the kinesin motor protein that drives motility
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作者：
Rice, S;Lin, AW;Vale, RD
驱动蛋白马达通过将ATP能量转化为沿沿着的单向运动来驱动许多运动过程。传统驱动蛋白的力产生和酶促性质已被广泛研究;然而，运动的结构基础是未知的。在这里，我们已经检测到并可视化了一个类似于15个氨基酸区域的大的构象变化使用电子顺磁共振、荧光共振能量转移、预稳态动力学和冷冻电子显微镜，对驱动蛋白中的颈连接体（neck linker）进行了研究。当驱动蛋白结合微管和ATP时，该区域变得固定并向微管“正”端延伸，并且当核苷酸水解后释放γ-磷酸时回复到更移动的构象。这种构象变化解释了驱动蛋白运动的方向和驱动蛋白二聚体的进行性运动。
Kinesin motors power many motile processes by converting ATP energy into unidirectional motion along microtubules, The force-generating and enzymatic properties of conventional kinesin have been extensively studied; however, the structural basis of movement is unknown. Here we have detected and visualized a large conformational change of a similar to 15-amino-acid region (the neck linker) in kinesin using electron paramagnetic resonance, fluorescence resonance energy transfer, pre-steady state kinetics and cryo-electron microscopy, This region becomes immobilized and extended towards the microtubule 'plus' end when kinesin binds microtubules and ATP, and reverts to a more mobile conformation when gamma-phosphate is released after nucleotide hydrolysis, This conformational change explains both the direction of kinesin motion and processive movement by the kinesin dimer.