Banères J L, Martin A, Parello J
UPRESA CNRS 5074, Chimie Biomoléculaire et Interactions Biologiques, Faculté de Pharmacie, 34060 Montpellier, Cedex 2, France.
J Mol Biol. 1997 Oct 31;273(3):503-8. doi: 10.1006/jmbi.1997.1297.
The histone N tails correspond to conserved amino acid sequences that are peripherally located in the nucleosome and undergo a variety of post-synthetic modifications during cell cycle. These N tails have been recently recognized as directly interacting with transcription-related proteins. We show here, based on circular dichroic evidence, that the N tails of both tetrameric histones H3 and H4 are highly organized as DNA-bound polypeptide segments in the nucleosome core particle, with about half of their residues, taken together, being alpha-helical. In contrast, the N tails of both dimeric histones H2A and H2B are found essentially in a random-coil conformation. The implications of these findings on nucleosome structure and recognition are discussed.
组蛋白N端尾巴对应于保守的氨基酸序列，这些序列位于核小体的外周，并在细胞周期中经历各种合成后修饰。最近发现这些N端尾巴可直接与转录相关蛋白相互作用。我们在此基于圆二色性证据表明，四聚体组蛋白H3和H4的N端尾巴在核小体核心颗粒中作为与DNA结合的多肽片段高度有序排列，它们总共约一半的残基呈α螺旋结构。相比之下，二聚体组蛋白H2A和H2B的N端尾巴基本上呈无规卷曲构象。本文讨论了这些发现对核小体结构和识别的意义。
