Figure 5.
Energetics during neck travel. (A) Force vectors obtained using the TOWS simulation at the tip of the neck for the trajectory in Fig. 2. Forces range between 6 and 43 pN. Viewing direction is the same as in Fig. 1. (B) PMF curves obtained by integrating the components of the force vectors along the direction of travel, for forward (circles) and reverse (triangles) trajectories. Substeps marked 1–3 coincide with those in Fig. 2. For the reverse motion, two types of trajectories were used, with the MH rearranging before neck travel (HF; solid triangles), and with the neck moving first (NF; open triangles). (C) Comparison between forward and reverse trajectories at Rtip = 5 Å (near position 1) and 21 Å (before position 2). Arrows indicate the direction of travel. In the reverse trajectory, the R335-D424 bond is formed only when the neck has almost finished its travel (⋄ versus ⋆). (See Movie S3).