Figure 3.

(A) Scheme of the studied H38 segments with depicted interhelical α and β angles. The red helices schematically show the hinge-like dynamics. (B) Stereo superposition of the starting E.c. crystal structure (blue) and two MD snapshots representing open (black) and closed (green) conformations (Table 2). The simulated molecule does not move away the X-ray structure but shows considerable stochastic fluctuations. (C) Stereo superposition of average structure of the simulated E.c. segment (magenta) and the starting crystal structure (blue). See Supplementary Figure S8 for superposition over different trajectory portions. (D and E) Developments of interhelical α and β angles in performed Na⁺ simulations (the plots are averaged over 1 ps windows to make the curves smoother). Note that due to the profound local structural diversity of the structures the reference experimental (and also equilibrium) values of the α and β angles differ for different structures.