Efficient supercoiling of DNA by a single condensin complex as revealed by electron spectroscopic imaging
Efficient supercoiling of DNA by a single condensin complex as revealed by electron spectroscopic imaging
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DOI：
10.1016/s1097-2765(02)00546-4
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发表时间：
2002-06-01
期刊：
影响因子：
16
通讯作者：
Hirano, T
中科院分区：
文献类型：
--
作者：
Bazett-Jones, DP;Kimura, K;Hirano, T
凝聚素是一种五亚基蛋白复合物，在酵母到人类的有丝分裂染色体凝聚过程中发挥重要作用，在体外以ATP依赖的方式将正超螺旋引入DNA。我们在这里报告的直接可视化的超螺旋反应的电子光谱成像。在ATP存在的情况下，单个缩合素复合物能够将两个或更多个补偿性超螺旋引入闭合环状DNA的无蛋白质区域。在凝聚素结合区，类似于190 bp的DNA被组织成具有两个不同结构域的紧凑结构，表明形成了两个定向的回旋。目前的结果表明，凝聚素的行动是更动态和更有效的比以前假设的，提供了基本的洞察能量依赖性机制的高阶染色质折叠。
Condensin, a five-subunit protein complex essential for mitotic chromosome condensation from yeast to humans, introduces positive supercoils into DNA in an ATP-dependent manner in vitro. We report here the direct visualization of this supercoiling reaction by electron spectroscopic imaging. In the presence of ATP, a single condensin complex is capable of introducing two or more compensatory supercoils into the protein-free region of a closed circular DNA. Within the condensin-bound region, similar to190 bp of DNA is organized into a compact structure with two distinct domains, indicative of the formation of two oriented gyres. The current results suggest that the action of condensin is more dynamic and more efficient than that postulated before, providing fundamental insight into the energy-dependent mechanism of higher order chromatin folding.