Figure 1.

Orthosteric and allosteric binding sites of CB1R. (A) Extracellular view of the orthosteric and allosteric sites of CB1R (PDB ID 6KQI). Important orthosteric site residues S173^2.60, V196^3.32, I267^ECL2, W356^6.48, and S383^7.39, are shown in licorice representations (yellow). The CB1R agonist, CP55940 (purple), is shown in the orthosteric site, while the allosteric NAM, ORG27569, is shown in combined licorice and surface representations (light blue). (B) Membrane view of the orthosteric and allosteric binding sites of CB1R. Some of the key allosteric site residues, H154^2.41, G157^2.44, V161^2.48, V234^4.43, and W241^4.50, are shown in the licorice representation (magenta). ORG27569 is shown in light representation (light blue), while the agonist is shown in combined licorice and surface representations.