Cryo-EM structure of the adenosine A2Areceptor coupled to an engineered heterotrimeric G protein.
Garcia-Nafria, J., Lee, Y., Bai, X., Carpenter, B., Tate, C.G.(2018) Elife 7
- PubMed: 29726815
- DOI: https://doi.org/10.7554/eLife.35946
- Primary Citation of Related Structures:
6GDG - PubMed Abstract:
The adenosine A 2A receptor (A 2A R) is a prototypical G protein-coupled receptor (GPCR) that couples to the heterotrimeric G protein G S . Here, we determine the structure by electron cryo-microscopy (cryo-EM) of A 2A R at pH 7.5 bound to the small molecule agonist NECA and coupled to an engineered heterotrimeric G protein, which contains mini-G S , the βγ subunits and nanobody Nb35. Most regions of the complex have a resolution of ~3.8 Å or better. Comparison with the 3.4 Å resolution crystal structure shows that the receptor and mini-G S are virtually identical and that the density of the side chains and ligand are of comparable quality. However, the cryo-EM density map also indicates regions that are flexible in comparison to the crystal structures, which unexpectedly includes regions in the ligand binding pocket. In addition, an interaction between intracellular loop 1 of the receptor and the β subunit of the G protein was observed.
Organizational Affiliation:
MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.