FIGURE 5.

Analysis of the 1-μs SMD trajectory of ring 4 reveals thermally driven and force driven conformational transitions between gg, gt, and tg states. (A) Time trajectory evolution of the three torsions. The initial gg ↔ gt transitions occur at a minimal stretching force and therefore are driven thermally. The gg → tg transition at 368.52 ns is driven by the external force. (B) Time evolution of the O₁–O₆ distance reveals a stepwise increase at 368.52 ns due to the gg → tg transition. (C) Two structures of ring 4, separated by 10 ps, immediately before and after the gg → tg transition.