FIG. 10.

(Color online) Comparison between the unwinding and rewinding rates of the nucleosome inner turn, calculated according to the local interaction model of histone-DNA interactions, and calculated according to a model that posits a uniform binding free energy per unit length. The upper (red) solid and dashed lines correspond to the unwinding and rewinding rates, respectively, for the best-fit local interaction model for nucleosomes containing H4 The dotted line is the local interaction model, but omitting the ad hoc term, described in the text. Circles and squares correspond to the measured unwinding and rewinding rates, respectively, for nucleosomes containing H4. The lower solid and dashed curves correspond to the unwinding and rewinding rates, respectively, for a constant histone-DNA binding energy per bp, chosen so that at a force of 6 pN the free energies of 25 and 70 bp wound are equal.