Fig. 3. Spontaneous permeation of Cl⁻ through the TMEM16A pore.

A Number of coordinating waters of permeating Cl⁻ and its distance to the inner gate during the event (780–1030 ns of sim 3). The insert shows the hydrating water number of the same Cl⁻ ion in the whole simulation with the spontaneous permeation event highlighted by a dashed red box. B Representative snapshots during permeation. TMs 3 and 5 are represented as red cartoons and TMs 4 and 6 are colored in blue and green, respectively. The inner gate residues (L547, S592, and I641) are shown in yellow sticks. The permeating Cl⁻ ion is represented as a cyan sphere, with water molecules within 4 Å shown in the ball-and-stick mode.