Extended Data Fig. 4. Isoproterenol occupancy in orthosteric binding pocket of β₁-AR.

(a,b) Side view (a) and oblique view (b) of activated β₁-AR to highlight the location of the agonist isoproterenol bound in the orthosteric binding pocket at the extracellular side of the receptor. β₁-AR is shown in cartoon in red and isoproterenol is shown in green. Experimental density carved around ligand shown at 13σ, supporting complete occupancy. (c) Close-up view of the orthosteric binding pocket with model docked into 8σ experimental density to highlight agonist coordination. Isoproterenol is colored in green and residues lining the binding pocket are in red.