FIGURE 3.

(a) Thermodynamics of the nucleosome core particle. The dependence on temperature of the energy, E, is shown. The error bars represent a standard deviation of energy fluctuations. (b) Variation of the constant-volume heat capacity, C_v, of the nucleosome core particle with temperature. The error bars are the standard deviation of C_v fluctuations. NCP unfolding occurs at temperature T = 0.92. (c) Temperature dependence of frequencies of interhistone contacts. Histone chains making contacts in constant-temperature simulations of the histone-octamer complex are shown for temperatures T = 0.3–0.8. Frequencies of interhistone contacts are color-coded from white (contact frequency of 0) to black (contact frequency of 1). Under high-temperature conditions, the frequencies of contact are significantly reduced; however, novel interhistone contacts are not observed, indicating the absence of intranucleosome domain swap.