Figure 2. Positions of methionines in active and inactive β₂AR structures.

A) Methionine residues shown as sticks in the active and inactive β₂AR crystal structures. Solid spheres represent the methionine methyl carbons left in β₂AR-Δ5, whereas dotted spheres represent methyls of methionines mutated to other residues in β₂AR-Δ5. The functional properties of β₂AR-Δ5 are similar to those of wild-type β₂AR (See also Fig. S1). B) Structure of β₂AR in the crystallographic inactive conformation (2RH1) seen from the intracellular side. Leu272^6.34 and surrounding hydrophobic residues are shown as sticks. C) Structure of β₂AR in the crystallographic active conformation (3P0G) seen from the intracellular side.