Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules.
Direct observation shows superposition and large scale flexibility within cytoplasmic dynein motors moving along microtubules.
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直接观察显示沿微管运动的细胞质动力蛋白电动机内的叠加和大规模柔韧性。
DOI：
10.1038/ncomms9179
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发表时间：
2015-09-14
影响因子：
16.6
通讯作者：
Burgess SA
中科院分区：
文献类型：
--
作者：
Imai H;Shima T;Sutoh K;Walker ML;Knight PJ;Kon T;Burgess SA
细胞质动力蛋白是一种二聚体AAA+马达蛋白，通过使用ATP沿着微管移动在真核细胞中发挥关键作用。在这里，使用冷冻电子显微镜，我们直接观察在近生理ATP浓度的微管上的Dictyosteelium discoideum dynein二聚体的结构。它们在靠近微管结合域（茎头）的铰链处显示出显着的灵活性，产生广泛的头部位置。大约一半的分子有两个彼此分开的头部，前导和尾随马达都连接到微管上。另一半有两个头和柄紧密重叠在AAA+环的前后排列中，表明头之间的特定接触。所有柄都指向微管的负端。平均茎角取决于它们的茎头之间的间隔，这允许估计头间张力。这些发现为理解动力蛋白的方向性和不寻常的步进行为提供了一个结构框架。细胞质动力蛋白是一种二聚体蛋白质，沿着微管前进。在这里，Imai等人展示了步进D的冷冻电子显微镜图像。discoideum动力蛋白，揭示了不同的微管结合的配置，包括铰链依赖，电机并排安排。
Cytoplasmic dynein is a dimeric AAA+ motor protein that performs critical roles in eukaryotic cells by moving along microtubules using ATP. Here using cryo-electron microscopy we directly observe the structure of Dictyostelium discoideum dynein dimers on microtubules at near-physiological ATP concentrations. They display remarkable flexibility at a hinge close to the microtubule binding domain (the stalkhead) producing a wide range of head positions. About half the molecules have the two heads separated from one another, with both leading and trailing motors attached to the microtubule. The other half have the two heads and stalks closely superposed in a front-to-back arrangement of the AAA+ rings, suggesting specific contact between the heads. All stalks point towards the microtubule minus end. Mean stalk angles depend on the separation between their stalkheads, which allows estimation of inter-head tension. These findings provide a structural framework for understanding dynein's directionality and unusual stepping behaviour. Cytoplasmic dynein is a dimeric protein that steps processively along microtubules. Here Imai et al. present cryo-electron microscopy images of stepping D. discoideum dynein, revealing diverse microtubule-bound configurations including a hinge-dependent, motors side-by-side arrangement.