Figure 2.

Schematic drawings of the nucleosome, highlighting features that contribute to nucleosome dynamics. (A) Illustration highlighting energetically important contacts within the nucleosome. The DNA entry/exit region (red) has weaker histone–DNA contacts, and the dyad region (blue) has the most energetically important contacts.⁴⁹ Superhelical locations (SHLs) indicate the histone surfaces where contact is made with the DNA minor groove.⁹² The histone surface underneath the DNA at the dyad, where the major groove faces the histone octamer, is considered SHL-0, and increasing or decreasing values mark each SHL moving from the dyad to the two entry/exit regions. (B) Map of histone residues where post-translational modifications influence nucleosome dynamics.