Three-dimensional structure of cytoplasmic dynein bound to microtubules
Three-dimensional structure of cytoplasmic dynein bound to microtubules
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DOI：
10.1073/pnas.0710406105
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发表时间：
2007-12-26
影响因子：
11.1
通讯作者：
Kikkawa, Masahide
中科院分区：
文献类型：
--
作者：
Mizuno, Naoko;Narita, Akihiro;Kikkawa, Masahide
细胞质动力蛋白是一种大的微管依赖性分子马达（1.2 MDa）。虽然动力蛋白本身的结构已被表征，但其与微管复合的构象仍是未知的。在这里，我们使用冷冻电子显微镜（cryo-EM）可视化动力蛋白和微管之间的相互作用。大多数动力蛋白分子在无核苷酸状态下以确定的构象和方向与微管结合。3D图像重建显示，由AAA+结构域的环状排列形成的动力蛋白的头部结构域位于距离微管中心约280埃的位置。通过使用重组标记物确定环中AAA+结构域的顺序。此外，具有动力蛋白微管结合结构域[动力蛋白柄（DS）]的微管的3D螺旋图像重建显示，该柄垂直于微管延伸。通过结合动力蛋白微管和DS-微管复合物的3D地图，我们提出了一个模型，动力蛋白在无核苷酸状态下如何与微管结合，并讨论了动力蛋白的动力冲程模型。
Cytoplasmic dynein is a large, microtubule-dependent molecular motor (1.2 MDa). Although the structure of dynein by itself has been characterized, its conformation in complex with microtubules is still unknown. Here, we used cryoelectron microscopy (cryo-EM) to visualize the interaction between dynein and microtubules. Most dynein molecules in the nucleoticle-free state are bound to the microtubule in a defined conformation and orientation. A 3D image reconstruction revealed that dynein's head domain, formed by a ring-like arrangement of AAA+ domains, is located approximate to 280 angstrom away from the center of the microtubule. The order of the AAA+ domains in the ring was determined by using recombinant markers. Furthermore, a 3D helical image reconstruction of microtubules with a dynein's microtubule binding domain [dynein stalk (DS)] revealed that the stalk extends perpendicular to the microtubule. By combining the 3D maps of the dynein-microtubule and DS-microtubule complexes, we present a model for how dynein in the nucleoticle-free state binds to microtubules and discuss models for dynein's power stroke.