Figure 11.5: The nucleosome is the fundamental repeating unit of chromatin. Part (d) shows a space-filling model of the core particle, which consists of two copies each of H2A, H2B, H3, and H4, around which DNA (white) coils.
[Part d: Reprinted by permission from Macmillan Publishers Ltd. From K. Luger et al., Nature 389:251. © 1997. Courtesy of T. H. Richmond.]