Figure 5.

Binding mode of (A) isoproterenol (7, orange carbon atoms) in the turkey β₁AR (PDB code 2Y03 (Warne et al., 2012)). Proposed binding modes of endogenous agonists, based on SDM studies, of (B) dopamine (35, blue carbon atoms) in the human D₃R and the proposed binding modes of histamine (8, magenta carbon atoms) in the different human histamine receptors; (C) H₁R, (D) H₂R, (E) H₃R and (F) H₄R. Minor changes in the H₁R crystal structure (i.e. rotation of K191^5.39 and N198^5.46) allow for accommodation of histamine. The H₂R, H₃R and H₄R models are based on the H₁R crystal structure. Rendering and colour-coding are the same as in Figure 2. (G) Molecular interaction fingerprint (IFP) bit strings describing the binding poses of 7–8 and 35 (A–F), encoding different interaction types with D^3.32, 5.42, 5.46, 6.52, 6.55 and 7.39 (colour-coding as described in Figure 2). Two-dimensional structures of the molecules are presented in Figure 3A and B.