Extended Data Fig. 3: Volta phase-plate imaging of the CGRP–CLR–RAMP1–Gs complex.
From: Cryo-EM structure of the active, Gs-protein complexed, human CGRP receptor
a, Volta phase-plate micrograph of the complex (representative of 3,180 movies). High-contrast phase-plate imaging facilitates robust particle selection despite low defocus and tight packing of particles. b, RELION 2D class averages. c, Workflow for map refinement. d, Final 3D cryo-EM map calculated in RELION after auto-refinement and map sharpening. e, Gold standard Fourier shell correlation curve; the overall nominal resolution is 3.26 Å. f, Model overfitting was evaluated by randomly displacing all atoms by 0.5 Å and refined against one cryo-EM half map. Fourier shell correlation curves were calculated between the resulting model and the half map used for refinement (green); the resulting model and the other half map for cross validation (red), and the final refined model and the full map (blue). g, Potential lipid interaction with the base of TM4 and TM2 of CLR.
