Portugal J, Waring M J
Nucleic Acids Res. 1987 Feb 11;15(3):885-903. doi: 10.1093/nar/15.3.885.
Two fragments of Xenopus borealis DNA 135 and 189 base-pairs long were separately incorporated into nucleosome core particles by reconstitution with chicken erythrocyte histones, and incubated with echinomycin (a bis-intercalating antitumor antibiotic) or distamycin (a minor groove-binding, non-intercalating antibiotic). Controlled digestion of these defined sequence core particles using DNAase I revealed new cleavage products, indicative of a change in orientation of the DNA molecule on the surface of the nucleosome. This new rotational setting of DNA within the core particle induced by antibiotic binding appears to be practically independent of DNA sequence, although some differences were noted between the patterns of fragments observed in the various experiments, most likely reflecting the exact number and disposition of the antibiotic binding sites.
将135个碱基对长和189个碱基对长的非洲爪蟾DNA的两个片段分别与鸡红细胞组蛋白重组，掺入核小体核心颗粒中，并与棘霉素（一种双嵌入抗肿瘤抗生素）或偏端霉素（一种结合小沟、非嵌入抗生素）一起孵育。使用DNA酶I对这些定义序列的核心颗粒进行受控消化，发现了新的切割产物，这表明核小体表面上DNA分子的方向发生了变化。抗生素结合诱导的核心颗粒内DNA的这种新的旋转设置似乎实际上与DNA序列无关，尽管在各种实验中观察到的片段模式之间存在一些差异，最有可能反映了抗生素结合位点的确切数量和分布。
