3-DIMENSIONAL STRUCTURE OF THE KINESIN HEAD-MICROTUBULE COMPLEX
3-DIMENSIONAL STRUCTURE OF THE KINESIN HEAD-MICROTUBULE COMPLEX
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DOI：
10.1038/376274a0
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发表时间：
1995-07-20
期刊：
影响因子：
64.8
通讯作者：
HIROKAWA, N
中科院分区：
文献类型：
--
作者：
KIKKAWA, M;ISHIKAWA, T;HIROKAWA, N
KINESIN 是一种与微管 (MT) 相关的“运动”分子，是细胞器运输的基础 (1,2)。最近，各种驱动蛋白超家族成员 (KIF) 也已被鉴定并被认为负责特定细胞器的运输(3-5)。驱动蛋白是由两条重链和两条轻链组成的异四聚体。重链形成两个球状头部、一根杆和一个由轻链(6,7)完成的扇形尾部。球状头由重链的约 340 个氨基末端残基组成，包括 ATP 结合域和 MT 结合域，其重组蛋白也具有这些特性 (8)。为了加深对基于 MT 的分子马达驱动蛋白产生力的机制的理解，我们在这里报告了重组驱动蛋白头和 MT 复合物的三维结构，如通过冷冻电子显微照片的螺旋重建所揭示的。驱动蛋白头是一种球状泪滴状结构，与 MT 一根原丝的脊结合。我们已经确定了 MT 复合物和驱动蛋白头结构的极性与 MT 极性的关系。
KINESIN is a microtubule (MT)-associated 'motor' molecule fundamental to organelle transport(1,2). Recently, various kinesin superfamily members (KIFs) have also been identified and suggested as being responsible for the transport of specific organelles(3-5). Kinesin is a heterotetramer composed of two heavy chains and two light chains. The heavy chains form two globular heads, a rod and a fan-like tail completed by the light chains(6,7). The globular head, which is composed of approximately 340 amino-terminal residues of the heavy chain, includes both ATP-binding and MT-binding domains, and its recombinant protein also has these properties(8). To improve the understanding of the mechanism of force generation by an MT-based molecular motor, kinesin, we report here the three-dimensional structure of the complex of a recombinant kinesin head and MTs, as revealed by helical reconstruction from cryoelectron micrographs. A kinesin head is a globular teardrop-like structure binding to the ridge of one protofilament of MTs. We have determined the polarity of the structure of the complex of MTs and the kinesin head in relation to MT polarity.