A model for the microtubule-Ncd motor protein complex obtained by cryo-electron microscopy and image analysis
A model for the microtubule-Ncd motor protein complex obtained by cryo-electron microscopy and image analysis
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DOI：
10.1016/s0092-8674(00)80330-x
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发表时间：
1997-07-25
期刊：
影响因子：
64.5
通讯作者：
Milligan, RA
中科院分区：
文献类型：
--
作者：
Sosa, H;Dias, DP;Milligan, RA
驱动蛋白马达将ATP水解产生的化学能转化为单向运动。为了了解驱动蛋白马达如何与微管结合并沿着微管移动，我们将Ncd马达结构域（一种参与减数分裂和有丝分裂的驱动蛋白马达）的原子结构拟合到通过冷冻电子显微镜和图像分析计算的Ncd微管复合物的三维密度图中。该模型揭示了Ncd与微管共享广泛的相互作用表面，并且结合位点的一部分涉及含有保守残基的环。在Ncd二聚体中，微管结合的马达结构域与其从微管解离的伴侣头部密切接触。这种头-头的相互作用可能是重要的，在定位解离的头部采取一个步骤的下一个结合位点的微管原丝。
Kinesin motors convert chemical energy from ATP hydrolysis into unidirectional movement. To understand how kinesin motors bind to and move along microtubules, we fit the atomic structure of the motor domain of Ncd (a kinesin motor involved in meiosis and mitosis) into three-dimensional density maps of Ncd-microtubule complexes calculated by cryo-electron microscopy and image analysis. The model reveals that Ncd shares an extensive interaction surface with the microtubule, and that a portion of the binding site involves loops that contain conserved residues. In the Ncd dimer, the microtubule-bound motor domain makes intimate contact with its partner head, which is dissociated from the microtubule. This head-head interaction may be important in positioning the dissociated head to take a step to the next binding site on the microtubule protofilament.