Fig. 4: Intracellular face of KnChR.

a Water accessible cavities, viewed from the intracellular side. The C-terminal region is highlighted. b The residues in the C-terminal region are shown as sticks with transparent CPK models. c Close-up view of the c-terminal region. Based on density, R287 was modeled in two ways, including an alternative conformation. Black two-way arrows indicate distances between two atoms. d Close-up view of R291 and POPC. Black dashed lines indicate hydrogen bonds. e Representative photocurrent traces of KnChR-697 and mutants. The cells were illuminated (λ = 470 nm) during the time indicated by blue bars. The membrane voltage was clamped from −60 to +40 mV for every 20-mV step. f Comparison of photocurrent amplitudes of KnChR-697 and mutants at −60 mV. In the bar graph, gray bars indicate the amplitude from the peak photocurrent (Ip), and open bars indicate the amplitude from the steady-state photocurrent (Iss). n = 5 to 6 cells. Source data are provided as a Source Data file. g The channel-closing kinetics of KnChR-697 and mutants after illumination cessation (τ-off) at −60 mV. n = 5 to 6 cells. All data in (f, g) are expressed as mean ± SEM and were evaluated with the Mann-Whitney U test for statistical significance. It was judged as statistically insignificant when p > 0.05. It was judged as statistically insignificant when p < 0.05. *p < 0.05, **p < 0.01 *** p < 0.005. Source data are provided as a Source Data file.