Fig. 6.

Occupancy of water molecules inside the TMEM16A pore. (A) Representative calculations of the average occupancy of the water molecules inside the pore of the open TMEM16A channel over the last 100 ns of an 800-ns simulation with and without Ca²⁺. The occupancy of the water molecules is shown in blue. The phosphate headgroups are shown as dark gray spheres. The protein is represented as cartoon in orange. V539 and I636 are shown in green. Ca²⁺ is shown in pink. (B) Calculated minimum distance between V539 and I636 in the Ca²⁺-bound (red) and the Ca²⁺-free (black) state across 800-ns simulations (n = 3). The lighter shaded lines show the distance calculated every 10 ps, and the darker lines show running averages over 1 ns. (C) Histogram showing V539-I636 distance in the last 100 ns of the simulations. The two conditions, Ca²⁺-bound (red) and the Ca²⁺-free (black) states, were sampled with the bin size of 0.17 Å and sampled every 1 ns (n = 3).