Estimation of tension in the disordered neck linker region using MD simulations of refined dimer models. (A) Time trajectories of the trends of tension during 100-ns simulations, using model systems (Fig. S4 D) derived from refined dimer models with various open and closed head combinations (Fig. 6). Tensions were calculated by multiplying the deviation of the Cα atoms at both ends of the disordered neck linkers from the potential minimum. The trend at each time t was calculated by averaging raw tension values within the time range [t − 0.5: t + 0.5] ns. Trends converged at ∼35 ns for the T_closed-L_closed model and within 2 ns for the other three models. (B) Distributions of tension in disordered neck linkers, obtained from MD simulations. The green vertical lines indicate time-averaged tension for each state after convergence. (C) Time-average tensions and statistical errors for each state: 38.7 ± 0.8 pN for T_closed-L_open, 124.9 ± 1.5 pN for T_closed-L_closed, 98.1 ± 1.2 pN for T_open-L_open, 115.7 ± 1.2 pN for T_open-L_closed.