驱动蛋白
微管
生物
细胞生物学
微管蛋白
ATP酶
运动蛋白
生物化学
酶
作者
Andrew W. Hunter,Michael Caplow,David L. Coy,William O. Hancock,Stefan Diez,Linda Wordeman,Jonathon Howard
出处
期刊:Molecular Cell
[Elsevier]
日期:2003-02-01
卷期号:11 (2): 445-457
被引量:351
标识
DOI:10.1016/s1097-2765(03)00049-2
摘要
MCAK belongs to the Kin I subfamily of kinesin-related proteins, a unique group of motor proteins that are not motile but instead destabilize microtubules. We show that MCAK is an ATPase that catalytically depolymerizes microtubules by accelerating, 100-fold, the rate of dissociation of tubulin from microtubule ends. MCAK has one high-affinity binding site per protofilament end, which, when occupied, has both the depolymerase and ATPase activities. MCAK targets protofilament ends very rapidly (on-rate 54 micro M(-1).s(-1)), perhaps by diffusion along the microtubule lattice, and, once there, removes approximately 20 tubulin dimers at a rate of 1 s(-1). We propose that up to 14 MCAK dimers assemble at the end of a microtubule to form an ATP-hydrolyzing complex that processively depolymerizes the microtubule.
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