How does an acetylation affect the conformation of H3 histone tail ?

Ikebe, Kimiyoshi; Sakuraba, Shun*; Kono, Hidetoshi

In eukaryotic cells, genome DNA is stored in a complex with histone proteins (H3, H4, H2A and H2B). Acetylation to terminal regions of histones (histone tails) is generally believed to regulate gene expression through dissociation of tails from DNA, although conformations of disordered tails remain poorly understood. In this work, we examined differences in conformational ensembles of H3 tail with or without K14 acetylation using adaptive lambda square dynamics simulation. The result suggested that the acetylation does not make the tail dissociate from DNA. Instead, it enhanced secondary structure formation of the tail and unwrapping of DNA from the structured histone core regions. This study elucidated the first step of the gene regulation mechanism.