Fig. 2: Orthosteric and allosteric binding sites.
From: Activation and allosteric regulation of the orphan GPR88-Gi1 signaling complex
a, b The unassigned electron density observed in the canonical orthosteric pocket of GPR88. Blue, structure without 2-PCCA (a); green, structure bound to 2-PCCA (b). c The charge distribution of the orthosteric pocket is shown in two different views. d, e The molecular surface of the allosteric pocket from bottom (d) and side (e) views. f, g Detailed interactions between 2-PCCA and the allosteric pocket from bottom (f) and side (g) views. Polar interactions are highlighted as dashed lines. h–j Cell-surface expression (h) and Gi-coupling activity (i, j) were analyzed by the flow cytometry and the NanoBiT-Gi dissociation assay, respectively. From the concentration–response curves (Supplementary Fig. 4), Emax (i) and ∆pEC50 (j) values relative to the wild type were calculated. Colors in the mutant bars indicate an expression level matching to that of titrated wild type. NA, parameter not available because of lack of the ligand response. Statistical analyses were performed using the ordinary one-way ANOVA followed by the two-sided Sidak’s post hoc test with the expression-matched (colored) WT response. ns, p > 0.05; *p < 0.05; **p < 0.01; ***p < 0.001. Bars and error bars represent mean and s.e.m. of 3 independent experiments, denoted as the parenthesis at the bottom of the figure panels. Source data are provided as a Source data file.
