Condensin and cohesin display different arm conformations with characteristic hinge angles.
Condensin and cohesin display different arm conformations with characteristic hinge angles.
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DOI：
10.1083/jcb.200111002
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发表时间：
2002-02-04
期刊：
影响因子：
--
通讯作者：
Hirano T
中科院分区：
文献类型：
--
作者：
Anderson DE;Losada A;Erickson HP;Hirano T
染色体结构维持（SMC）蛋白在从细菌到人类的高阶染色体动力学中起着核心作用。在真核生物中，两种不同的SMC蛋白复合物，凝聚素和凝聚素，分别调节染色体凝聚和姐妹染色单体凝聚。每个复合物由SMC亚基和两个或三个非SMC亚基的异二聚体对组成。先前的研究表明，细菌SMC同源二聚体具有对称的结构，其中两个长的卷曲螺旋臂通过柔性铰链连接。一个具有DNA和ATP结合活性的催化结构域位于每个arm.We在这里报告的可视化脊椎动物凝聚素和凝聚素的电子显微镜。这两种复合物都显示出SMC蛋白质的双臂结构特征，但它们的构象明显不同。冷凝器的铰链关闭，并且盘绕的线圈臂被紧密地放置在一起。相比之下，粘着蛋白的铰链是敞开的，并且卷曲的螺旋彼此分开。凝聚素和粘蛋白的非SMC亚基形成与SMC异二聚体的催化结构域结合的球状复合物。我们认为凝聚素的“闭合”构象和黏连素的“开放”构象是重要的结构特性，有助于其专门的生化和生理功能。
Structural maintenance of chromosomes (SMC) proteins play central roles in higher-order chromosome dynamics from bacteria to humans. In eukaryotes, two different SMC protein complexes, condensin and cohesin, regulate chromosome condensation and sister chromatid cohesion, respectively. Each of the complexes consists of a heterodimeric pair of SMC subunits and two or three non-SMC subunits. Previous studies have shown that a bacterial SMC homodimer has a symmetrical structure in which two long coiled-coil arms are connected by a flexible hinge. A catalytic domain with DNA- and ATP-binding activities is located at the distal end of each arm. We report here the visualization of vertebrate condensin and cohesin by electron microscopy. Both complexes display the two-armed structure characteristic of SMC proteins, but their conformations are remarkably different. The hinge of condensin is closed and the coiled-coil arms are placed close together. In contrast, the hinge of cohesin is wide open and the coiled-coils are spread apart from each other. The non-SMC subunits of both condensin and cohesin form a globular complex bound to the catalytic domains of the SMC heterodimers. We propose that the “closed” conformation of condensin and the “open” conformation of cohesin are important structural properties that contribute to their specialized biochemical and physiological functions.
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DOI：
10.1083/jcb.151.4.749
发表时间：
2000-11-13
期刊：
The Journal of cell biology
影响因子：
--
作者：
Sumara I;Vorlaufer E;Gieffers C;Peters BH;Peters JM
通讯作者：
Peters JM
影响因子：
64.5
作者：
Kimura, K;Hirano, T
通讯作者：
Hirano, T
影响因子：
10.5
作者：
Sutani, T;Yuasa, T;Yanagida, M
通讯作者：
Yanagida, M
影响因子：
11.4
作者：
Hirano, M;Anderson, DE;Hirano, T
通讯作者：
Hirano, T
影响因子：
10.5
作者：
Tomonaga, T;Nagao, K;Yanagida, M
通讯作者：
Yanagida, M