Open AccessHigh‐resolution structure of the native histone octamer
Author(s) -
Wood Christopher M.,
Nicholson James M.,
Lambert Stanley J.,
Chantalat Laurent,
Reynolds Colin D.,
Baldwin John P.
Publication year - 2005
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309105013813
Subject(s) - histone octamer , nucleosome , chemistry , histone h4 , histone , chromatosome , biophysics , crystallography , linker dna , biology , dna , biochemistry
Crystals of native histone octamers (H2A–H2B)–(H4–H3)–(H3′–H4′)–(H2B′–H2A′) from chick erythrocytes in 2 M KCl, 1.35 M potassium phosphate pH 6.9 diffract X‐rays to 1.90 Å resolution, yielding a structure with an R work value of 18.7% and an R free of 22.2%. The crystal space group is P 6 5 , the asymmetric unit of which contains one complete octamer. This high‐resolution model of the histone‐core octamer allows further insight into intermolecular interactions, including water molecules, that dock the histone dimers to the tetramer in the nucleosome‐core particle and have relevance to nucleosome remodelling. The three key areas analysed are the H2A′–H3–H4 molecular cluster (also H2A–H3′–H4′), the H4–H2B′ interaction (also H4′–H2B) and the H2A′–H4 β‐sheet interaction (also H2A–H4′). The latter of these three regions is important to nucleosome remodelling by RNA polymerase II, as it is shown to be a likely core‐histone binding site, and its disruption creates an instability in the nucleosome‐core particle. A majority of the water molecules in the high‐resolution octamer have positions that correlate to similar positions in the high‐resolution nucleosome‐core particle structure, suggesting that the high‐resolution octamer model can be used for comparative studies with the high‐resolution nucleosome‐core particle.