LOCATION OF THE ATPASE SITE OF MYOSIN DETERMINED BY 3-DIMENSIONAL ELECTRON-MICROSCOPY
LOCATION OF THE ATPASE SITE OF MYOSIN DETERMINED BY 3-DIMENSIONAL ELECTRON-MICROSCOPY
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DOI：
10.1038/329635a0
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发表时间：
1987-10-15
期刊：
影响因子：
64.8
通讯作者：
WAKABAYASHI, T
中科院分区：
文献类型：
--
作者：
TOKUNAGA, M;SUTOH, K;WAKABAYASHI, T
肌球蛋白对ATP的水解和伴随的肌动蛋白和肌球蛋白的循环结合-解离都是肌肉收缩所必需的。了解肌球蛋白的两个主要功能位点：ATPase位点1和肌动蛋白结合位点2的三维位置对于了解肌球蛋白收缩的分子机制是很重要的。我们利用电子显微镜的三维图像重建和亲和素-生物素系统的位点特异性标记确定了肌球蛋白的ATPase位点的位置。ATPase位点距肌球蛋白头部约5 nm，距肌球蛋白肌动蛋白结合部位约4 nm。这是首次用电子显微镜对酶活性部位进行三维定位的报道。
Both ATP hydrolysis by myosin and the accompanying cyclic association–dissociation of actin and myosin are essential for muscle contraction. It is important for understanding the molecular mechanism of contraction to know the three-dimensional locations of the two major functional sites of myosin: the ATPase site1and the actin-binding site2,3. We have determined the position of the ATPase site of myosin using three-dimensional image reconstruction from electron micrographs and site-specific labelling with the avidin–biotin system1. The ATPase site is about 5 nm from the tip of the myosin head and is about 4 nm away from the actin-binding site of myosin. This is the first report of the three-dimensional location of an enzyme active site by electron microscopy.