Figure 8. Alignment of the human dopamine receptor 4 (DRD₄) with zebrafish (Danio rerio), coelacanth (Latimeria chalumnae) and spotted gar (Lepisosteus oculatus) dopamine receptor 4rs (DRD_4rs).

Shaded regions denote transmembrane domains according to UniProt. Dopamine binding sites (red dots) were determined by site directed mutagenesis (Cummings et al., 2010) and homology to DRD₂. Antagonist binding sites and hydrophobic pocket-including selectivity region-were obtained from mutagenesis studies (Cummings et al., 2010) and from the crystal structure of the receptor coupled to the antagonist nemonapride (Wang et al., 2017). Non-conserved amino acids in the nemonapride binding pocket are labeled with green asterisks. Binding sites for the selective agonist UCSF924 are also shown (light blue dot).