Atomic force microscopy sees nucleosome positioning and histone H1‐induced compaction in reconstituted chromatin

FEBS Letters

Hanaoka, Fumio²  Hohmura, Ken I.¹  Yoshimura, Shige H.¹  Sato, Masa H.¹  Tokumasu, Fuyuki¹  Ura, Kiyoe²  Takeyasu, Kunio¹ 

[1] Department of Natural Environmental Sciences, Faculty of Integrated Human Studies, Kyoto University, Yoshida-Nihonmatsu-cho, Sakyo-ku, Kyoto 606-8501, Japan;Institute for Molecular and Cellular Biology, Osaka University, Yamada-oka, Suita, Osaka 565-0871, Japan

关键词: Atomic force microscopy;    Dinucleosome;    Chromatin structure;    Nucleosome positioning;    Histone H1;    Nucleosome compaction;   

DOI  :  10.1016/S0014-5793(99)00644-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We addressed the question of how nuclear histones and DNA interact and form a nucleosome structure by applying atomic force microscopy to an in vitro reconstituted chromatin system. The molecular images obtained by atomic force microscopy demonstrated that oligonucleosomes reconstituted with purified core histones and DNA yielded a ‘beads on a string’ structure with each nucleosome trapping 158±27 bp DNA. When dinucleosomes were assembled on a DNA fragment containing two tandem repeats of the positioning sequence of the Xenopus 5S RNA gene, two nucleosomes were located around each positioning sequence. The spacing of the nucleosomes fluctuated in the absence of salt and the nucleosomes were stabilized around the range of the positioning signals in the presence of 50 mM NaCl. An addition of histone H1 to the system resulted in a tight compaction of the dinucleosomal structure.

【 授权许可】

Unknown