Histone octamer rearranges to adapt to DNA unwrapping.

ABSTRACT: Nucleosomes, the basic units of chromatin, package and regulate expression of eukaryotic genomes. Although the structure of the intact nucleosome is well characterized, little is known about structures of partially unwrapped, transient intermediates. In this study, we present nine cryo-EM structures of distinct conformations of nucleosome and subnucleosome particles. These structures show that initial DNA breathing induces conformational changes in the histone octamer, particularly in histone H3, that propagate through the nucleosome and prevent symmetrical DNA opening. Rearrangements in the H2A-H2B dimer strengthen interaction with the unwrapping DNA and promote nucleosome stability. In agreement with this, cross-linked H2A-H2B that cannot accommodate unwrapping of the DNA is not stably m

SUBMITTER: Bilokapic S 

PROVIDER: S-EPMC5800490 | biostudies-literature | 2018 Jan

REPOSITORIES: biostudies-literature