Fig. 6: Proposed mechanisms for the PGT transport and the moonlighting channel activity.
From: Molecular basis of prostaglandin E2 reuptake by organic anion transporter PGT
a Schematic representation of the alternating access transport cycle. The conformational states 1–3 are captured in this study, and the states 4–5 in faint shade are deduced from the AlphaFold2 prediction model and recent structural information of MFSD2A and Spns2. b Schematic representation of the proposed transport-to-channel conversion. Dashed lines in the ECD depict presumed flexibility. Upon assembling with other Maxi-Cl channel components, PGT undergoes conformational changes that expand the translocation funnel, deforming the gate near the extracellular interface (Gate 1), which is required for PGs transport (as depicted in (a)). Near the intracellular interface, Gate 2 is spared for ion passage in the channel-like configuration.
