Figure 1. Structure of the nucleosome (pdb code 1aoi).
DNA is shown in grey, H2A in yellow, H2B in red, H3 in blue, and H4 in green, respectively. Only one of the two H2A-H2B dimers is shown in each panel for clarity. The molecular two-fold axis dissecting the H3 four-helix bundle is indicated by a dashed line. Regions of interaction between the H2A-H2B dimer and the (H3-H4)2 tetramer are indicated by solid ovals (left panel), whereas homotypic interactions between H3 or H2A are indicated by dashed ovals (right panel).