FIGURE 1. Schematic diagram of the 
2AR.
From the following article:
Crystal structure of the human 
2 adrenergic G-protein-coupled receptor
Søren G. F. Rasmussen, Hee-Jung Choi, Daniel M. Rosenbaum, Tong Sun Kobilka, Foon Sun Thian, Patricia C. Edwards, Manfred Burghammer, Venkata R. P. Ratnala, Ruslan Sanishvili, Robert F. Fischetti, Gebhard F. X. Schertler, William I. Weis & Brian K. Kobilka
Nature 450, 383-387(15 November 2007)
doi:10.1038/nature06325
Black circles with white letters indicate disordered residues not included in the model. Grey letters and circles indicate residues not included in the 2AR365 construct used for crystallography. Red letters indicate amino acids for which side-chain electron density was not modelled. Yellow residues indicate amino acids implicated in ligand binding from mutagenesis studies. Orange residues indicate the conserved DRY sequence. Green residues form the Fab5 epitope, and pink residues are packed against the Fab5 constant domain in the lattice. Small blue circles indicate glycosylation sites. Red lines indicate ten-amino-acid increments.
