ジャーナル: Mol Cell / 年: 2017 タイトル: Structure and Dynamics of a 197 bp Nucleosome in Complex with Linker Histone H1. 著者: Jan Bednar / Isabel Garcia-Saez / Ramachandran Boopathi / Amber R Cutter / Gabor Papai / Anna Reymer / Sajad H Syed / Imtiaz Nisar Lone / Ognyan Tonchev / Corinne Crucifix / Hervé Menoni / ...著者: Jan Bednar / Isabel Garcia-Saez / Ramachandran Boopathi / Amber R Cutter / Gabor Papai / Anna Reymer / Sajad H Syed / Imtiaz Nisar Lone / Ognyan Tonchev / Corinne Crucifix / Hervé Menoni / Christophe Papin / Dimitrios A Skoufias / Hitoshi Kurumizaka / Richard Lavery / Ali Hamiche / Jeffrey J Hayes / Patrick Schultz / Dimitar Angelov / Carlo Petosa / Stefan Dimitrov / 要旨: Linker histones associate with nucleosomes to promote the formation of higher-order chromatin structure, but the underlying molecular details are unclear. We investigated the structure of a 197 bp ...Linker histones associate with nucleosomes to promote the formation of higher-order chromatin structure, but the underlying molecular details are unclear. We investigated the structure of a 197 bp nucleosome bearing symmetric 25 bp linker DNA arms in complex with vertebrate linker histone H1. We determined electron cryo-microscopy (cryo-EM) and crystal structures of unbound and H1-bound nucleosomes and validated these structures by site-directed protein cross-linking and hydroxyl radical footprinting experiments. Histone H1 shifts the conformational landscape of the nucleosome by drawing the two linkers together and reducing their flexibility. The H1 C-terminal domain (CTD) localizes primarily to a single linker, while the H1 globular domain contacts the nucleosome dyad and both linkers, associating more closely with the CTD-distal linker. These findings reveal that H1 imparts a strong degree of asymmetry to the nucleosome, which is likely to influence the assembly and architecture of higher-order structures.