Implications for kinetochore-microtubule attachment from the structure of an engineered Ndc80 complex
Implications for kinetochore-microtubule attachment from the structure of an engineered Ndc80 complex
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DOI：
10.1016/j.cell.2008.03.020
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发表时间：
2008-05-02
期刊：
影响因子：
64.5
通讯作者：
Musacchio, Andrea
中科院分区：
文献类型：
--
作者：
Ciferri, Claudio;Pasqualato, Sebastiano;Musacchio, Andrea
动粒是介导染色体与有丝分裂纺锤体相互作用的蛋白质组装体。180 kDa Ndc 80复合物是着丝粒和微管之间的直接接触点。它的四个亚基含有卷曲螺旋，并形成一个细长的杆结构，两端有功能性球状结构域。我们结晶了一个工程化的“bonsai '”Ndc 80复合物，它含有缩短的杆状结构域，但保留了动粒定位和微管结合所需的球状结构域。该结构揭示了一个微管结合界面包含一对紧密相互作用的钙调蛋白同源（CH）结构域与以前未知的安排。与微管的相互作用是合作的，主要是静电。它涉及CH结构域和Ndc 80亚基N-末端尾部的正电荷和微管蛋白C-末端尾部的负电荷，并受Aurora B激酶调节。我们讨论了我们的研究结果，参照目前的模型kinetochore-microtubule附件和着丝粒组织。
Kinetochores are proteinaceous assemblies that mediate the interaction of chromosomes with the mitotic spindle. The 180 kDa Ndc80 complex is a direct point of contact between kinetochores and microtubules. Its four subunits contain coiled coils and form an elongated rod structure with functional globular domains at either end. We crystallized an engineered "bonsai'' Ndc80 complex containing a shortened rod domain but retaining the globular domains required for kinetochore localization and microtubule binding. The structure reveals a microtubule-binding interface containing a pair of tightly interacting calponin-homology (CH) domains with a previously unknown arrangement. The interaction with microtubules is cooperative and predominantly electrostatic. It involves positive charges in the CH domains and in the N-terminal tail of the Ndc80 subunit and negative charges in tubulin C-terminal tails and is regulated by the Aurora B kinase. We discuss our results with reference to current models of kinetochore-microtubule attachment and centromere organization.