Structure of an agonist-bound human A2A adenosine receptor.
Xu, F., Wu, H., Katritch, V., Han, G.W., Jacobson, K.A., Gao, Z.G., Cherezov, V., Stevens, R.C.(2011) Science 332: 322-327
- PubMed: 21393508 
- DOI: https://doi.org/10.1126/science.1202793
- Primary Citation of Related Structures:  
3QAK - PubMed Abstract: 
Activation of G protein-coupled receptors upon agonist binding is a critical step in the signaling cascade for this family of cell surface proteins. We report the crystal structure of the A(2A) adenosine receptor (A(2A)AR) bound to an agonist UK-432097 at 2.7 angstrom resolution. Relative to inactive, antagonist-bound A(2A)AR, the agonist-bound structure displays an outward tilt and rotation of the cytoplasmic half of helix VI, a movement of helix V, and an axial shift of helix III, resembling the changes associated with the active-state opsin structure. Additionally, a seesaw movement of helix VII and a shift of extracellular loop 3 are likely specific to A(2A)AR and its ligand. The results define the molecule UK-432097 as a "conformationally selective agonist" capable of receptor stabilization in a specific active-state configuration.
Organizational Affiliation: 
Department of Molecular Biology, Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.