Fig. 4: Comparison of conductance across different simulation setups.

a Conductance derived from simulations of the pore domain and the voltage-sensor domain (VSD) of the CNGA1 channel with K⁺ (blue) and Na⁺ (red) under various transmembrane voltages. b Conductance derived from simulations of the whole CNGA1 channel with K⁺ under –100 mV and +100 mV. c Conductance derived from simulations of pore domain only of the CNGA1 channel with K⁺ (blue) and Na⁺ (red, pink) under different transmembrane voltages. “D. R.” represents simulations with distance restraints on gate residues F389, based on distances of the open state in the cryo-EM structures²⁷. Open circle represents the simulated conductance from each 100 ns segment, while the closed circle shows the averaged value from all data points. Conductance from experimental single-channel recordings for K⁺ (blue, 20.0 ± 1.3 pS, +100 mV) and Na⁺ (red, 36.0 ± 1.7 pS, +100 mV) from a previous study¹⁰ are shown as dashed lines, with error margins represented by shaded areas. A statistical t test was performed from 45 segments for each simulation setup (each 1 µs trajectory was divided into 10 segments and the first 100 ns segment was considered as equilibration phases and discarded), and p values were calculated to assess the significance of the difference between the simulated K⁺ and Na⁺ conductance in the pore+VSD construct. Sample size for each simulation setup: 45. [The exact p values: -200 mV: 0.0103; -100 mV: 0.0006; +100 mV: 0.0001; +200 mV: 0.8919. Not significant (ns): p > 0.05; significant (*): p ≤ 0.05; very significant (**): p ≤ 0.01; highly significant (***): p ≤ 0.001]. The simulated current-voltage relationships of the pore domain alone and pore+VSD constructs are shown in Supplementary Fig. S4.