Fig. 2.

Nucleosomal DNA accessibility PTMprints for acetylated lysine residues within the globular histone core. a Schematic of the different DNA regions. b Accessibility of the different nucleosomal DNA regions without a PTM. The very low probability of the global region accessibility corresponds to the simultaneously unwrapping of 78 bp of the DNA. c and d show change in accessibility, (P*/P), upon lysine acetylation, by region. c Entry/Exit, and d global region. The horizontal dashed lines indicate the conservative threshold value used to define a functionally significant change in accessibility. The threshold value corresponds to the accessibility change of H4K31 for the entry/exit region, and to H4K79 for global accessibility. Note that the entry/exit nucleosomal DNA is accessible in multiple states (U, T, P1, P2, P3); the global region is only accessible in the T and U states, Fig. 1