G-protein coupled receptor experimental structures and their ligands used in this study.

Data collected from the Protein Data Bank.aLoop lengths determined by DSSP.bLigand conformers generated by MOE. The fold decrease in sampling efficiency is the uniform sampling efficiency within a 2.0 Å radius (USE2.0) for the bioactive ligand conformation divided by USE2.0 for ligand conformers.cNumber of water molecules bridging the receptor and ligand within 4 Å of the ligand crystallized in the binding pocket.dNumber of residues in the receptor in contact with the ligand. Indicated is the number of contacts within the transmembrane region of the receptor binding pocket versus the loop or N-terminal regions.