Extended Data Figure 9: CTR-Gs protein interactions.
From: Phase-plate cryo-EM structure of a class B GPCR–G-protein complex
a, The α5-helix of Gαs (orange) docks into a cavity formed on the intracellular side of the receptor (blue) by the opening of TM6. G-protein side chains within this cavity are supported by the cryo-EM map. b, Helix 8 of the CTR forms an amphipathic helix with multiple bulky aromatics heavily embedded within the detergent micelle that are evident in the map. Residues within the more polar face of helix 8 are in the vicinity of Gβ, where they probably form polar interactions, although specific side chain density in this region is not evident. c, ICL1 is located in close proximity to the G protein. A common CTR splice variant contains a 16 amino acid insertion within this loop (between Arg174 and Ser175), an insertion that would sterically hinder G-protein interactions with the receptor.
