FIGURE 15.

Time series of the angles β and β′ describing the orientation of the last ss DNA segment, b and b′, respectively, during the pulling simulations at large forces (30–60 pN), for the open state (top panel) and closed state (bottom panel). For the open state the segment b has oriented toward the direction of the external force at smaller forces (between 8 and 10 pN; see Fig. 9). In the bottom panel of this figure, for the closed state, the evolution of the β′-angle shows that b′ experiences this “crossover” phenomenon at forces larger than 40 pN.