STRUCTURAL STUDIES ON MICROTUBULE MOTORS

工作的长期目标是了解作用机制 与微管相互作用的机械化学酶。的目标 是使用低温电子显微镜和图像分析 建立一个微管的中等分辨率三维信息数据库 修饰有驱动蛋白和NCD的运动域， 不存在不可水解的ATP类似物。这两个运动域具有 类似的序列，但在微管上以相反的方向行进。的 所获得的三维图谱将显示这些马达如何与微管相互作用 原丝，并应提供见解的构象变化 发生在这些功能不同的分子的运动域 在他们的依恋周期中。此外，金簇标记将是 用来定位马达表面的残留物 获得的数据将补充正在收集的高分辨率数据 在其他实验室中，对微管蛋白的锌片（Downing，Berkeley）和3- 运动域的D晶体（Vale & Fletterick，UCSF; Goldstein， UCSD）。中等分辨率的电磁数据的电机轨道复杂和高 分辨率X射线和EM地图的各个组成部分，从其他 这两个实验室都将是建立发动机原子模型的必要条件 附着在微管上。这种方法的结合非常 在肌动球蛋白系统的研究中取得了成功。 这项工作福尔斯基础生物医学研究的范畴，因为它 不是针对某一种疾病，而是有一个基本的、根本的 健康和疾病状态的相关性。这里获得的数据 将提供深入了解细胞内和轴突的机制， 运输和细胞分裂过程中的染色体运动。最终 数据可能对理解这些正常的疾病很重要， 细胞过程异常

The long-term goals of the work are to understand the mechanism of action of the mechanochemical enzymes which interact with microtubules. The goals of this application are to use cryo-electron microscopy and image analysis to build a database of moderate resolution 3-D information on microtubules decorated with the motor domains of kinesin and NCD in the presence and absence of a non-hydrolyzable ATP analogue. These two motor domains have similar sequences but travel in opposite directions on microtubules. The 3-D maps obtained will show how these motors interact with the microtubule protofilaments and should provide insights into the conformational changes occurring in the motor domain of these functionally distinct molecules during their attachment cycle. In addition, gold cluster labelling will be used to localize surface residues on the motors. The data obtained will complement the high resolution data being collected in other laboratories on zinc sheets of tubulin (Downing, Berkeley) and 3- D crystals of the motor domains (Vale & Fletterick, UCSF; Goldstein, UCSD). Moderate resolution EM data on the motor-track complex and the high resolution x-ray and EM maps of the individual components from other laboratories will both be essential for building an atomic model of motors attached to microtubules. Such a combination of approaches has been very successful in studying the actomyosin system. This work falls into the category of Basic Biomedical Research in that it is not targeted to a particular disease but has a basic and fundamental relevance for both the healthy and diseased states. The data obtained here will provide insights into the mechanisms of intracellular and axonal transport, and chromosome movements during cell division. Ultimately, the data may prove important for understanding diseases where these normal cellular processes are aberrant.