Figure 5. Summary of selectivity determining amino acids within theβ2AR-Gα_s- and the D2R-Gα_i-complexes and representative values of the alanine scanning mutagenesis.

The grey columns in the middle refer to the regions within GPCRs and G-proteins, to which the mentioned amino acids belong. Amino acids in italic letters have not been mutated in the computational alanine scanning (n.d.). Blue, green and red bars show the binding free energy differences of the alanine scanning mutagenesis for the β2AR-Gα_s complex and the D2^DownR-Gα_i and the D2^UpR-Gα_i-complexes, respectively. The orange and red rectangles besides the amino acids correspond to hydrophobic or polar interactions to other residues, respectively.