Histones H1 and H5 interact preferentially with crossovers of double-helical DNA.
Histones H1 and H5 interact preferentially with crossovers of double-helical DNA.
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组蛋白 H1 和 H5 优先与双螺旋 DNA 的交叉相互作用。
DOI：
10.1073/pnas.90.11.5052
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发表时间：
1993
影响因子：
11.1
通讯作者：
Zlatanova,J
中科院分区：
文献类型：
--
作者：
Krylov,D;Leuba,S;vanHolde,K;Zlatanova,J
研究了鸡红细胞染色质连接蛋白H1和H5与pBR 322的相互作用，作为环状质粒分子中超螺旋圈数的函数。超螺旋质粒DNA放松与拓扑异构酶I，使人口与一个狭窄的分布的拓扑异构体，包含从零到五个超螺旋的转折，获得。没有拓扑异构体包含替代的非B-DNA结构。通过琼脂糖凝胶电泳分析在25或100 mM NaCl终浓度和组蛋白-DNA摩尔比范围为10至150时形成的组蛋白-DNA复合物。个别拓扑异构体条带从凝胶中消失的模式被解释为接头组蛋白对双螺旋DNA交叉的偏好的指示。在两种盐浓度下都观察到这种偏好，在低离子强度条件下更加明显。孤立的H5球状结构域也导致选择性的拓扑异构体从凝胶中消失，但它只在非常高的肽-DNA摩尔比。所观察到的接头组蛋白对双螺旋DNA交叉的偏好被认为是组蛋白八聚体周围两圈DNA密封机制的一部分。
The interaction of the linker histones H1 and H5 from chicken erythrocyte chromatin with pBR322 was studied as a function of the number of superhelical turns in circular plasmid molecules. Supercoiled plasmid DNA was relaxed with topoisomerase I so that a population with a narrow distribution of topoisomers, containing from zero to five superhelical turns, was obtained. None of the topoisomers contained alternative non-B-DNA structures. Histone-DNA complexes formed at either 25 or 100 mM NaCl final concentration and at histone-DNA molar ratios ranging from 10 to 150 were analyzed by agarose gel electrophoresis. The patterns of disappearance of individual topoisomer bands from the gel were interpreted as an indication of preference of the linker histones for crossovers of double-helical DNA. This preference was observed at both salt concentrations, being more pronounced under conditions of low ionic strength. Isolated H5 globular domain also caused selective disappearance of topoisomers from the gel, but it did so only at very high peptide-DNA molar ratios. The observed preference of the linker histones for crossovers of double-helical DNA is viewed as a part of the mechanism involved in the sealing of the two turns of DNA around the histone octamer.