25 Angstrom resolution structure of a cytoplasmic dynein motor reveals a seven-member planar ring.
25 Angstrom resolution structure of a cytoplasmic dynein motor reveals a seven-member planar ring.
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细胞质动力蛋白马达的 25 埃分辨率结构揭示了七元平面环。
DOI：
10.1016/j.jmb.2004.05.063
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Koonce,MichaelP
中科院分区：
文献类型：
--
作者：
Samso,Montserrat;Koonce,MichaelP
Dyneins form one of the three major families of cytoskeleton-based motor proteins that together drive most of the visible forms of cell and organelle movement. We present here a 3D reconstruction of a cytoplasmic dynein motor domain obtained by electron microscopy, at 25Å resolution. This work demonstrates a basic motor architecture of a flat, slightly elliptical ring composed of seven densities arranged around a partially enclosed central cavity. We have used specific Fab tags to localize the microtubule-binding domain; the connecting stalk emerges at one end of the motor's long axis. Through proposed fitting of representative AAA domain structures, we show that the nucleotide catalytic P-1 domain is likely located at the opposite end of the motor. Thus mechanisms that couple nucleotide hydrolysis with microtubule binding must be propagated around a ring structure, in a manner clearly distinct from kinesin or myosin-mediated movements. Analysis of the Fab tagged datasets reveals classes of particles with stalks protruding at distinct angles from the motor. There is a ∼40° variation in microtubule-binding stalk angle that may reflect linkage to dynein's mechanochemical cycle. Overall, the work provides sufficient resolution to begin the mapping of landmark features onto a dynein motor, and provides a foundation for understanding the mechanics of dynein movement.
