Vik1 modulates microtubule-Kar3 interactions through a motor domain that lacks an active site
Vik1 modulates microtubule-Kar3 interactions through a motor domain that lacks an active site
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DOI：
10.1016/j.cell.2006.12.046
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发表时间：
2007-03-23
期刊：
影响因子：
64.5
通讯作者：
Gilbert, Susan P.
中科院分区：
文献类型：
--
作者：
Allingham, John S.;Sproul, Lisa R.;Gilbert, Susan P.
常规驱动蛋白和V类和VI类肌球蛋白协调其马达结构域的机械化学循环，用于货物沿着微管或肌动蛋白丝的进行性运动。普遍认为这种协调是通过马达结构域之间的变构通讯或机械应变来实现的，其控制核苷酸状态以及与微管或肌动蛋白的相互作用。然而，关于菌株和核苷酸状态之间的相互作用仍然存在问题。我们提出了一个分析酿酒酵母Kar 3/Vik 1，异源二聚体的C-末端驱动蛋白14含有催化Kar 3和非马达蛋白Vik 1。Vik 1的X射线晶体结构显示出与驱动蛋白和肌球蛋白催化头相似的折叠，但缺乏ATP结合位点。Vik 1比Kar 3更紧密地与微管结合，并通过Kar 3/Vik 1异源二聚体促进合作微管装饰，但允许运动。这些结果需要Vik 1和Kar 3之间通过协调它们与微管相互作用的机制进行通信。
Conventional kinesin and class V and VI myosins coordinate the mechanochemical cycles of their motor domains for processive movement of cargo along microtubules or actin filaments. It is widely accepted that this coordination is achieved by allosteric communication or mechanical strain between the motor domains, which controls the nucleotide state and interaction with microtubules or actin. However, questions remain about the interplay between the strain and the nucleotide state. We present an analysis of Saccharomyces cerevisiae Kar3/Vik1, a heterodimeric C-terminal Kinesin-14 containing catalytic Kar3 and the nonmotor protein Vik1. The X-ray crystal structure of Vik1 exhibits a similar fold to the kinesin and myosin catalytic head, but lacks an ATP binding site. Vik1 binds more tightly to microtubules than Kar3 and facilitates cooperative microtubule decoration by Kar3/Vik1 heter-odimers, and yet allows motility. These results demand communication between Vik1 and Kar3 via a mechanism that coordinates their interactions with microtubules.