Fig. 7: MD simulations of S4 voltage sensor movement during activation/deactivation reveal a correlation with E116/K449 salt bridge stability.
From: Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain
a Cartoon representation of the S4–S5/S6T contact region in Kv3.1a, showing the positions of the R326/R332 H-bond and the salt bridge E116A/K449 between α6 in the T1 domain and S6T. b Comparison of the Z-position of the R4 dating charge relative to the CTC (boxplot) and the stability of the E116/K440 (violet bars) for each subunit under activating conditions (+300 mV). Data calculated from 750 ns (12,000 frames) following the movement of R4 Arginine (SI Fig. S15). The salt-bridge was assumed to form in frames with distance between the heavy atoms of the residues being <3.3 Å. Boxes span the interquartile range and whiskers extend up to 1.5 times this range. c, d Comparison of the Z-position of the R4 gating charge relative to the CTC (boxplot) and the stability of the E116/K440 (violet bars) for each subunit under deactivating conditions (−650 mV) from two independent trajectories. Data calculated from 750 ns (12,000 frames) following the movement of R4 arginine. The salt-bridge was assumed to form in frames with distance between the heavy atoms of the residues being <3.3 Å. Boxes span the interquartile range and whiskers extend up to 1.5 times this range. Source data for b–d are provided as a Source Data file.
