Three-dimensional reconstruction of the dynactin complex by single-particle image analysis
Three-dimensional reconstruction of the dynactin complex by single-particle image analysis
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DOI：
10.1073/pnas.0409506102
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发表时间：
2005-03-08
影响因子：
11.1
通讯作者：
Steffen, W
中科院分区：
文献类型：
--
作者：
Hodgkinson, JL;Peters, C;Steffen, W
动力蛋白是一种由至少九种不同蛋白质组成的大复合物，它们与细胞内的细胞质动力蛋白共同复合，在细胞内起着调节运动功能的重要作用。由于其庞大的尺寸和复杂性，对dynactin的3D结构或其功能的结构基础知之甚少。使用单粒子图像分析技术，使我们能够产生第一个三维重建的dynactin复合物，分辨率为3 nm。肌动蛋白相关蛋白（阿普）骨架的细丝已被清楚地可视化。对阿普骨架的模型拟合表明，它由10个亚基组成。还观察到非阿普骨架部分的额外肿块。帽蛋白CapZ结构到我们的三维重建的dynactin复合物的初步拟合表明，它是最佳的位置，以执行其拟议的功能作为一个稳定剂的Arp 1骨干，并提供线索，可能的相互作用点之间的帽蛋白和阿普亚基。结果提供了第一个详细的可视化dynactin复合物，并阐明了它的几个组成蛋白质之间的相互作用模式及其可能的功能。
Dynactin is a large complex of at least nine distinct proteins that co-complexes with cytoplasmic dynein within cells, where it plays a major role as a regulator of the motor's function. Owing to its large size and complexity, relatively little is known about dynactin's 3D structure or the structural basis of its function. Use of single-particle image analysis techniques has enabled us to produce the first 3D reconstruction of the dynactin complex, to a resolution of 3 nm. The actin-related protein (Arp) backbone of the filament has been clearly visualized. Fitting of models of the Arp backbone showed that it consists of 10 subunits. Additional mass, not part of the Arp backbone, was also seen. A preliminary fitting of the capping protein CapZ structure into our 3D reconstruction of the dynactin complex suggests that it is optimally placed to perform its proposed function as a stabilizer of the Arp1 backbone and gives clues as to likely interaction points between the capping protein and Arp subunits. The results provide the first detailed visualization of the dynactin complex and shed light on the mode of interaction between several of its constituent proteins and their possible functions.