A topological interaction between cohesin rings and a circular minichromosome
A topological interaction between cohesin rings and a circular minichromosome
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DOI：
10.1016/j.cell.2005.07.018
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发表时间：
2005-09-23
期刊：
影响因子：
64.5
通讯作者：
Nasmyth, K
中科院分区：
文献类型：
--
作者：
Ivanov, D;Nasmyth, K
姐妹染色单体凝聚力取决于包含两个SMC亚基Smc 1和Smc 3的多蛋白凝聚素复合物，它们二聚化形成V形分子，在其两臂尖端具有ABC样ATP酶头部。黏连蛋白的Smc1和Smc3“头”由称为Scc1的α Kleisin亚基连接，形成直径约40 nm的三部分环。我们在这里表明，一些粘着蛋白仍然紧密结合到圆形的微型染色体纯化后，从酵母细胞和切割的粘着蛋白的环或微型染色体的DNA破坏他们的协会。这表明这里检测到的粘附素和染色质之间的稳定关联是拓扑的而不是物理的，这与DNA被困在粘附素环内的概念一致。
Sister chromatid cohesion depends on a multiprotein cohesin complex containing two SMC subunits, Smc1 and Smc3, that dimerize to form V-shaped molecules with ABC-like ATPase heads at the tips of their two arms. Cohesin's Smc1 and Smc3 "heads" are connected by an alpha kleisin subunit called Scc1, forming a tripartite ring with a diameter around 40 nm. We show here that some cohesin remains tightly bound to circular minichromosomes after their purification from yeast cells and that cleavage either of cohesin's ring or of the minichromosome's DNA destroys their association. This suggests that the stable association between cohesin and chromatin detected here is topological rather than physical, which is consistent with the notion that DNA is trapped inside cohesin rings.