Oudet P, Germond J E, Bellard M, Spadafora C, Chambon P
Philos Trans R Soc Lond B Biol Sci. 1978 May 11;283(997):241-58. doi: 10.1098/rstb.1978.0021.
Electron microscopic and biochemical results are presented supporting the following conclusions: (1) Two molecules of each histone H2A, H2B, H3 and H4 are necessary and sufficient to form a nucleosome with a diameter of 12.5 +/- 1 nm and containing about 200 base pairs of DNA. (2) H3 plus H4 alone can compact 129 +/- 8 DNA base pairs into a sub-nucleosomal particle with a diameter of 8 +/- 1 nm. In such a particle the DNA duplex is under a constraint equivalent to negative superhelicity. (3) Chromatin should be viewed as a dynamic structure, oscillating between a compact structure (the nucleosome) and more open structures, depending on the environmental conditions.
本文呈现了电子显微镜和生化实验结果，支持以下结论：（1）每种组蛋白H2A、H2B、H3和H4各两个分子对于形成直径为12.5±1纳米、包含约200个碱基对DNA的核小体是必要且充分的。（2）单独的H3加H4能将129±8个DNA碱基对压缩成直径为8±1纳米的亚核小体颗粒。在这样的颗粒中，DNA双链处于相当于负超螺旋的限制之下。（3）染色质应被视为一种动态结构，根据环境条件在紧密结构（核小体）和更开放的结构之间振荡。
