Structural Model for Tubulin Recognition and Deformation by Kinesin-13 Microtubule Depolymerases
Structural Model for Tubulin Recognition and Deformation by Kinesin-13 Microtubule Depolymerases
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DOI：
10.1016/j.celrep.2013.01.030
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发表时间：
2013-03-01
期刊：
影响因子：
8.8
通讯作者：
Sosa, Hernando
中科院分区：
文献类型：
--
作者：
Asenjo, Ana B.;Chatterjee, Chandrima;Sosa, Hernando
为了阐明微管解聚机制的驱动蛋白-13的结构基础，我们分析了微管蛋白和果蝇驱动蛋白-13 KLP 10A的复合物，通过电子显微镜（EM）和荧光偏振显微镜。我们报告了一个纳米分辨率（1.1 nm）冷冻电镜三维结构的KLP 10A头域（KLP 10AHD）绑定到弯曲的微管蛋白。我们发现，KLP 10 AHD的结合诱导了一个独特的微管蛋白结构，除了曲率之外，微管蛋白亚基之间还具有位移（剪切）。在这种结构中，驱动蛋白结合位点不同于直微管蛋白，这为驱动蛋白-13与微管晶格或其末端的不同相互作用模式提供了解释。KLP 10 AHD-微管蛋白界面包括三个相互作用区域，表明十字弓型微管蛋白弯曲机制。这些区域包括驱动蛋白-13家族保守的KVD残基，并且如从ESTA模型预测的，突变这些残基改变与微管相互作用的KLP 10AHD的方向和移动性。
To elucidate the structural basis of the mechanism of microtubule depolymerization by kinesin-13s, we analyzed complexes of tubulin and the Drosophila melanogaster kinesin-13 KLP10A by electron microscopy (EM) and fluorescence polarization microscopy. We report a nanometer-resolution (1.1 nm) cryo-EM three-dimensional structure of the KLP10A head domain (KLP10AHD) bound to curved tubulin. We found that binding of KLP10AHD induces a distinct tubulin configuration with displacement (shear) between tubulin subunits in addition to curvature. In this configuration, the kinesin-binding site differs from that in straight tubulin, providing an explanation for the distinct interaction modes of kinesin-13s with the microtubule lattice or its ends. The KLP10AHD-tubulin interface comprises three areas of interaction, suggesting a crossbow-type tubulin-bending mechanism. These areas include the kinesin-13 family conserved KVD residues, and as predicted from the crossbow model, mutating these residues changes the orientation and mobility of KLP10AHDs interacting with the microtubule.