Structural studies on dynein-microtubule complex

描述(申请人提供)：基于微管的马达，动力蛋白，是纳米级的蛋白质机器，将来自ATP水解的化学能转化为机械运动。机械运动被用于各种基本的细胞内运动，如轴突运输、染色体分离和鞭毛运动。动力蛋白功能的重要性在一些与动力蛋白相关的疾病中得到了强调，如Kartag‘s综合征和肌萎缩侧索硬化症(ALS)。然而，动力蛋白突变是如何导致原发纤毛运动障碍的，甚至动力蛋白是如何将化学能转化为机械运动的，人们知之甚少。 我们的长期目标是了解动力蛋白能量转换的结构基础及其调节。为此，我们将使用冷冻电子显微镜和三维重建来表征动力蛋白-微管复合体的结构。我们最近获得了动力蛋白-微管复合体的两个初步结构。一种是外臂动力蛋白-微管复合体的低分辨率结构，另一种是动力蛋白的微管结合域-动力蛋白茎的中等分辨率结构。我们目前的目标是将外臂动力蛋白-微管复合体的结构细化到25埃分辨率，并将动力蛋白柄结构的结构扩展到10埃分辨率。通过研究这些复合体在功能重要状态下的几种结构，我们想要阐明对动力蛋白的能量转换、运动和调节至关重要的构象变化。

DESCRIPTION (provided by applicant): Microtubule-based motors, dyneins, are nano-meter scale protein machineries and convert chemical energy derived from ATP hydrolysis to mechanical movement. The mechanical movement is employed for various essential intracellular motilities, such as axonal transport, chromosome segregation, and flagellar motility. The importance of dynein functions is underlined by several dynein-related diseases, such as Kartagener's syndrome and amyotrophic lateral sclerosis (ALS). However, little is known about how dynein mutations cause the primary cilia diskinesia or even how dyneins convert chemical energy to mechanical movement. Our long-term goal is to understand the structural basis of energy conversion by dynein and its regulation. To this end we will characterize the structure of dynein-microtubule complexes using cryo-electron microscopy and three-dimensional reconstruction. We have recently obtained two initial structures of dynein-microtubule complexes. One is a low resolution structure of the outer arm dynein-microtubule complex, and another is a medium resolution structure of the microtubule binding domain of dynein, the dynein stalk. Our immediate goals are to refine the structure of the outer arm dynein-microtubule complex to 25Angstroms resolution, and to extend the structure of the dynein stalk structure to 10Angstroms resolution. By studying several structures of these complexes in functionally important states, we would like to elucidate conformational changes essential to the energy conversion, motility and regulation of dynein.