Extended Data Fig. 6: The active structure of GPBAR in complex with Gs.

a, Structural representation of the important residues participating in GPBAR activation. The toggle switch residues W246^6.48 in the A2AR–Gs complex and W286^6.48 in β2AR–Gs complex undergoes one helical turn downshift referring to the central TM3 during the transition of the inactive state to active state. Notably, Y240^6.51 of GPBAR assumes the same position as W286^6.48 in the active β2AR-Gs complex, thus representing the active state. Structures involved in this panel include: inactive A2A (PDB ID 3EML), active A2A-Gs complex (PDB ID 5G53), inactive β2AR (PDB ID 3NYA), active β2AR-Gs complex (PDB ID 3SN6). b, Sequence alignment of the toggle switch W237 and the proline kink P176 in A2AR, β2AR and GPBAR from different species. P176 are colored in red and highlighted in yellow, W237 are colored in green and highlighted in yellow. c, Dose response curve of the INT-777 and other bile acid induced cAMP accumulation in Glosensor assay in cells overexpressing wild type or mutant GPBAR. Data from three independent measurements are measured as mean ± SEM. d, Lack of the compact structural P^5.50I^3.40F^6.44 motif in GPBAR structure. Left, structural rearrangement of the PIF motif during β2AR activation. Right, separation of P^5.50L^3.40F^6.44 in the GPBAR structure. Instead, W237^6.48 forms hydrophobic interactions with L100^3.40 and V178^5.52 to constitute a VLW motif in GPBAR.