Extended Data Fig. 4: Structural models and cryo-EM density of CaSR-G-protein complexes reconstituted in nanodiscs.
From: Promiscuous G-protein activation by the calcium-sensing receptor
Structural models of helices, loops and ligands within corresponding densities of the CaSR-miniGisq (a-d), CaSR-Gi3 (e-h) and CaSR-miniGis (i-l) complexes in nanodiscs. Residue labels signify the start and end of each helix or loop. CaSRfree (a, e, i) and CaSRG (b, f, j) TMD helices are displayed in blue and cyan, respectively, along with the co-agonist TNCA (gray) and PAM R-568 (yellow) in the corresponding subunit. The C-terminal module of Gα H5 helix (yellow), POPG (green), and CHS (magenta) are presented in (c), (g) and (k). CaSRG intracellular loops (ICL1, 2, 3) are shown in cyan in (d), (h) and (l). An ordered H8 helix is shown in cyan in (h). The density for CaSRfree TMD helices are displayed at contour levels of 0.3-0.5 (a), 0.1 (e), and 0.35 (i), while CaSRG TMD helices are contoured at 0.23-0.5 (b), 0.1 (f), and 0.35 (j). TNCA is contoured at 0.5 (a, b), 0.3 (e, f), and 0.35 (i, j), while R-568 is contoured at 0.18-0.3 (a, b), 0.01 (e, f), and 0.13-0.35 (i, j). POPG is contoured at 0.3 (c), 0.05 (g), and 0.15 (k). CHS is contoured at 0.3 (c), 0.1 (g), and 0.1 (k). The CaSRG ICLs are contoured at 0.15 in all complexes (d, h, l). The CaSRG H8 helix is contoured at 0.15 (h). The C-terminal module of Gα H5 helix is contoured at 0.5 (c), 0.3 (g), and 0.35 (k).
