Fig. 1: Cryo-EM structures of the ligand-free GLP-1R, GCGR, and GIPR in complex with Gs proteins.
From: Molecular features of the ligand-free GLP-1R, GCGR and GIPR in complex with Gs proteins
a, c, e Cryo-EM density maps of the GLP-1R–Gs (a), GCGR–Gs (c), and GIPR–Gs (e) complexes are shown from two viewpoints. GLP-1R, GCGR, GIPR, Gαs, Gβ, Gγ, and Nb35 are shown in orange, pale green, hot pink, slate gray, powder blue, khaki and light gray, respectively. The maps reveal several lipid densities around the receptors consistent with the shape of cholesterol (olive), palmitate (brown) or phosphatidylinositol 4,5-bisphosphate (purple). There is a strong unassigned cylindrical density in the shape of helix (green) dropping down along the TM4 and TM5 of GCGR, tentatively named as chain X (c). b, d, f Structural models of the GLP-1R–Gs (b), GCGR–Gs (d) and GIPR–Gs (f) complexes are constructed from the respective cryo-EM maps and shown in ribbon.
