Extended Data Fig. 5 |. Structural relationship between the observed water pocket and the gating helices in PCFT.

a, Cartoon of PCFT, showing the open and closed states of the extracellular and intracellular gates, respectively. b, Molecular dynamic simulations demonstrate the water pocket is both stable and accessible to bulk solvent via the substrate-binding cavity. The space occupied by the polar pocket results in fewer interactions between TM7 and TM10, which is likely to facilitate the movement of the helices against one another during transport.