Fig. 7.

(A) Allosteric Site 7 is located between TM3 (red)-TM5 (green)-TM6 (orange)-TM7 (cyan) in the intracellular mouth. In the X-ray structure, Site 7 clashes with TM6 that maintains strong interactions with TM3, precluding the binding of probe molecules. (B) In the active conformer, the bound probe molecules (ball-and-sticks) mainly interact with Arg121^3.50, Val125^3.54, Tyr206^5.58, Ile209^5.61, Thr386^6.34 and Tyr440^7.53 as highlighted in purple.