著者
岡 純 上田 国寛
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.19, no.2, pp.100-108, 1979-03-25 (Released:2009-05-25)
参考文献数
112

Recent studies on chromatin structure have elucidated a subunit structure called nucleosome, which consists of 200 base pairs of DNA, two molecules each of the histones H2A, H2B, H3 and H4, and one molecule of histone H1. The nucleosome core contains 140 base pairs of DNA coiled on the surface of a histone octamer. Nucleosome cores have been crystallized and shown to be flat particles with dimensions of 110×110×57Å.Nucleosomes seem to persist in DNA replication and transcription. Judging from the fact that the DNA coding for active genes is preferentially digested by DNase I, the templateactive chromatin has an altered conformation of nucleosomes. Evidence is accumulating to suggest that the increase in DNase I susceptibility of active genes is attributable to histone acetylation or to interactions with nonhistone proteins. Poly ADP-ribosylation of nuclear proteins is also suggested to play a role in chromatin function.