组蛋白H1与DNA相互作用的自旋标记研究。分子中心部分参与重组染色质的形成。

Spin-label study of histone H1-DNA interaction. Involvement of the central part of the molecule in reconstituted chromatin.

作者信息

Girardet J L, Lawrence J J

出版信息

Eur J Biochem. 1983 Apr 15;132(1):195-200. doi: 10.1111/j.1432-1033.1983.tb07347.x.

DOI:10.1111/j.1432-1033.1983.tb07347.x

Abstract

As shown in a previous paper [J. J. Lawrence et al. (1980) Eur. J. Biochem. 107, 263-269], covalent spin labeling of basis residues in histone H1 allows the study of the interaction of this protein with DNA. Using a step gradient dialysis procedure to reconstitute chromatin from labeled H1 and stripped chromatin, it is shown that the process of interaction of the lysine residues and DNA is the same whether histone H1 is bound to linear purified DNA or to H1-depleted chromatin. In contrast, spin labeling of the unique tyrosine of histone H1 located in the globular part of the molecule shows that this part is more involved in the interaction with chromatin than it is with linear DNA (as judged from the lengthening of the rotational correlation time). These data are interpreted as reflecting different roles for the N and C termini of the molecule of H1 and the central globular part. A model, based on these observations together with examination of the primary structures of histones H1, is proposed which accounts for the H1 involvement in the chromatosome structure.

摘要

如前一篇论文[J. J. 劳伦斯等人（1980年），《欧洲生物化学杂志》107卷，第263 - 269页]所示，对组蛋白H1中碱性残基进行共价自旋标记能够研究该蛋白与DNA的相互作用。使用逐步梯度透析程序，从标记的H1和去除H1的染色质中重构染色质，结果表明，无论组蛋白H1是与线性纯化DNA结合还是与去除H1的染色质结合，赖氨酸残基与DNA的相互作用过程都是相同的。相比之下，对位于分子球状部分的组蛋白H1独特酪氨酸进行自旋标记表明，该部分与染色质的相互作用比与线性DNA的相互作用更为密切（从旋转相关时间的延长判断）。这些数据被解释为反映了H1分子的N端和C端以及中央球状部分的不同作用。基于这些观察结果以及对组蛋白H1一级结构的研究，提出了一个模型，该模型解释了H1在核小体结构中的作用。