The directional preference of kinesin motors is specified by an element outside of the motor catalytic domain
The directional preference of kinesin motors is specified by an element outside of the motor catalytic domain
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DOI：
10.1016/s0092-8674(00)80360-8
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发表时间：
1997-09-05
期刊：
影响因子：
64.5
通讯作者：
Vale, RD
中科院分区：
文献类型：
--
作者：
Case, RB;Pierce, DW;Vale, RD
Kinesin超家族的成员共享相似的发动机催化域，但要么朝向微管的正端(例如，传统的Kinesin)，要么朝向微管的负端(例如，NCD)。决定运动极性的结构特征一直是个谜。在这里，我们证明了二聚体结构(560个残基)中的Kinesin的催化域(316个残基)可以被NCD的催化域取代，所得到的马达沿着Kinesin的方向移动。我们还证明了这种嵌合体不会在许多微管蛋白亚基上连续运动，这与NCD相似，但不同于传统的动蛋白的高度进行性运动。这些发现表明，催化域有助于运动过程，但不控制运动的极性。我们认为，邻近催化结构域的区域作为决定方向性的机械换能器。
Members of the kinesin superfamily share a similar motor catalytic domain yet move either toward the plus end (e.g., conventional kinesin) or the minus end (e.g., Ncd) of microtubules. The structural features that determine the polarity of movement have remained enigmatic. Here, we show that kinesin's catalytic domain (316 residues) in a dimeric construct (560 residues) can be replaced with the catalytic domain of Ncd and that the resultant motor moves in the kinesin direction. We also demonstrate that this chimera does not move processively over many tubulin subunits, which is similar to Ncd but differs from the highly processive motion of conventional kinesin. These findings reveal that the catalytic domain contributes to motor processivity but does not control the polarity of movement. We propose that a region adjacent to the catalytic domain serves as a mechanical transducer that determines directionality.