Fig. 2.

Ligand-receptor complexes. Cross-section through the A_2AR, highlighting the agonists adenosine (white sticks), NECA (cyan), CGS-21680 (pink), PSB-0777 (green) and LUF-5834 (blue) occupying the binding site. Color rectangles highlight regions of the orthosteric binding cavity that are occupied by functional groups of the studied agonists (see 3.2). The PIF motif (in yellow) located below the orthosteric binding cavity, and the side chain of the highly conserved R3.50 (in green) of the DRY motif near the G protein binding site are highlighted. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)