Reviewer #3 (Public review): Acetylation of H3K115 is associated with fragile nucleosomes at CpG island promoters and active regulatory sites

This fundamental study provides the first genome-wide characterization of H3K115 acetylation and identifies a striking and previously unappreciated association of this globular-domain histone modification with fragile nucleosomes at CpG island promoters, active enhancers, and CTCF binding sites.While the work is largely descriptive and correlative in nature the evidence is compelling.The authors present multiple, orthogonal genomic and biochemical analyses that consistently support their central conclusions.