Three-dimensional structures of the flagellar dynein-microtubule complex by cryoelectron microscopy
Three-dimensional structures of the flagellar dynein-microtubule complex by cryoelectron microscopy
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DOI：
10.1083/jcb.200609038
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发表时间：
2007-04-23
影响因子：
7.8
通讯作者：
Kikkawa, Masahide
中科院分区：
文献类型：
--
作者：
Oda, Toshiyuki;Hirokawa, Nobutaka;Kikkawa, Masahide
鞭毛轴丝的外动力蛋白臂(ODA)产生鞭毛跳动所需的力量。阐明动力蛋白臂的化学机械能量转换及其在纤毛/鞭毛中的协调运动的机制具有重要意义，但尚未观察到依赖核苷酸的动力蛋白三维运动。在这项研究中，我们建立了一种新的方法来重建体外重组的oda-微管复合体的三维结构，并使用冷冻电子显微镜和图像分析来可视化核苷酸依赖的构象变化。当复合体从僵硬状态变为松弛状态时，β重链的头部结构域向B小管移动3.7 nm，并向内倾斜44度。这些观察结果表明，存在一种将头部运动转换为轴线滑动运动的机制。
The outer dynein arms (ODAs) of the flagellar axoneme generate forces needed for flagellar beating. Elucidation of the mechanisms underlying the chemomechanical energy conversion by the dynein arms and their orchestrated movement in cilia/flagella is of great importance, but the nucleotide-dependent three-dimensional (3D) movement of dynein has not yet been observed. In this study, we establish a new method for reconstructing the 3D structure of the in vitro reconstituted ODA-microtubule complex and visualize nucleotide-dependent conformational changes using cryoelectron microscopy and image analysis. As the complex went from the rigor state to the relaxed state, the head domain of the beta heavy chain shifted by 3.7 nm toward the B tubule and inclined 44 degrees inwards. These observations suggest that there is a mechanism that converts head movement into the axonemal sliding motion.