Extended Data Fig. 1: Purification, characterization and cryo-EM images of the Rho–G_i–Fab complex.

a, Representative elution profile of the purified Rho–G_i–Fab_G50 complex on Superdex 200 10/300 gel filtration. b, SDS–PAGE analysis of the complex after gel filtration. c, The inability of rhodopsin to stimulate the G_s-mediated signalling as assayed by the cAMP-driven luciferase reporter assays. The glucagon-like peptide 1 receptor (GLP-1R) shows stronger G_s-meditated signalling with the agonist GLP-1 (n = 3 independent experiments). Data are mean ± s.d. d, An overall view of rhodopsin showing the three intramolecular distances between two nitroxide N–O bonds based on the models of the R1 nitroxide pairs Y74R1-Q225R1, Y74R1-R252R1 and Y74R1-M308R1, respectively (Y74^2.41, Q225^5.60, R252^6.35, M308^7.55; superscripts denote Ballesteros–Weinstein numbering). R1 side-chain modelling details have been described previously²⁷. e, Similar DEER distance distributions of TM6 and TM7 to TM2 of rhodopsin bound to G_i and G_t. f, Time domain data of DEER measurements.