30 nm Chromatin Fibre Decompaction Requires both H4-K16 Acetylation and Linker Histone Eviction

• Published in: Journal of molecular biology 2008-09, Vol.381 (4), p.816-825
• Main Authors: Robinson, Philip J.J., An, Woojin, Routh, Andrew, Martino, Fabrizio, Chapman, Lynda, Roeder, Robert G., Rhodes, Daniela
• Format: Article
• Language: English
• Subjects: 30 nm fibre; Acetylation; Amino Acid Sequence; Animals; Chickens; chromatin; Chromatin - genetics; Chromatin - metabolism; Drosophila melanogaster; histone acetylation; Histones - chemistry; Histones - metabolism; linker histone; Lysine - metabolism; MOF; Molecular Sequence Data; Nucleosomes - genetics; Nucleosomes - metabolism; Oligonucleotide Array Sequence Analysis; Recombinant Proteins - metabolism; Sequence Deletion; Xenopus
• ISSN: 0022-2836; 1089-8638
• DOI: 10.1016/j.jmb.2008.04.050

The mechanism by which chromatin is decondensed to permit access to DNA is largely unknown. Here, using a model nucleosome array reconstituted from recombinant histone octamers, we have defined the relative contribution of the individual histone octamer N-terminal tails as well as the effect of a targeted histone tail acetylation on the compaction state of the 30 nm chromatin fiber. This study goes beyond previous studies as it is based on a nucleosome array that is very long (61 nucleosomes) and contains a stoichiometric concentration of bound linker histone, which is essential for the formation of the 30 nm chromatin fiber. We find that compaction is regulated in two steps: Introduction of H4 acetylated to 30% on K16 inhibits compaction to a greater degree than deletion of the H4 N-terminal tail. Further decompaction is achieved by removal of the linker histone.