Fig. 4

3D and H-bond analysis of S1PR2 amino acid residue exchanges at position 108. H-bonds are predicted by the modeling program PyMol. The amino acid in position 108 is marked in magenta. H-bonds are marked in grey dashes. The interacting amino acids are labeled. a WT arginine and b mutant glutamine at position 108. Small grey arrows present missing H-bonds. c Crystal structure of S1PR1 (3v2y). The p.Arg120Gln substitution (magenta) is described in relation to the ligand ML056. The amino acids p.121Glu and p.120Arg build ionic and H-bonds (yellow dashes) with the ligand ML056 (yellow structure). The Å-distances are listed at the yellow dashes. d Chemical structure of the sphingosine-1-phosphate. e The chemical structure of the S1P analog, ML056. The dashed grey lines show the polar interactions between amino acids of S1PR1 and the ligand and the purple lines represent the hydrophobic interactions of ML056 with the amino acids of S1PR1 [29]