The cohesin ring concatenates sister DNA molecules
The cohesin ring concatenates sister DNA molecules
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DOI：
10.1038/nature07098
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发表时间：
2008-07-17
期刊：
影响因子：
64.8
通讯作者：
Nasmyth, Kim
中科院分区：
文献类型：
--
作者：
Haering, Christian H.;Farcas, Ana-Maria;Nasmyth, Kim
姐妹染色单体的凝聚是有丝分裂所必需的，它是由一种称为凝聚素的多亚基蛋白复合物介导的。黏连蛋白的Scc 1、Smc 1和Smc 3亚基形成了一个三重环结构，并且已经提出黏连蛋白通过将姐妹DNA分子捕获在其环内而将它们保持在一起。为了测试这一点，我们使用位点特异性交联在环的三个组成多肽之间的三个界面处产生化学连接，从而产生共价闭合的粘附素环。正如环捕获模型所预测的，该过程产生了对蛋白质变性具有抗性的二聚体DNA -粘附素结构。我们的结论是，凝聚环连接个别姐妹微型染色体DNA分子。
Sister chromatid cohesion, which is essential for mitosis, is mediated by a multi- subunit protein complex called cohesin. Cohesin's Scc1, Smc1 and Smc3 subunits form a tripartite ring structure, and it has been proposed that cohesin holds sister DNA molecules together by trapping them inside its ring. To test this, we used site- specific crosslinking to create chemical connections at the three interfaces between the three constituent polypeptides of the ring, thereby creating covalently closed cohesin rings. As predicted by the ring entrapment model, this procedure produced dimeric DNA - cohesin structures that are resistant to protein denaturation. We conclude that cohesin rings concatenate individual sister minichromosome DNA molecules.