Fig. 2.

Sequence alignment of the human P2YRs. Residues that have been identified using site-directed mutagenesis, as involved in ligand binding and/or receptor activation at P2Y₁R (Abbracchio et al., 2006; Zhang et al., 2015), P2Y₂R (Erb et al., 1995; Hillmann et al., 2009), P2Y₄R (Herold et al., 2004), P2Y₁₁R (Zylberg et al., 2007), and P2Y₁₂R (Hoffmann et al., 2008; Mao et al., 2010; Ignatovica et al., 2012; Zhang et al., 2014a,b) are highlighted with different colors: residues whose mutation can have a major effect on ligand binding and/or receptor activation (red); residues whose mutation modulates ligand binding and/or receptor activation (orange); and residues whose mutation has a minor or no effect on ligand binding and/or receptor activation (yellow). Residues within 3 Å from the crystallographic pose of 2MeSADP at P2Y₁₂R or within 3 Å from the crystallographic pose of MRS2500 at P2Y₁R are circled in green. The most highly conserved residue among GPCRs of each helix is highlighted in gray. Cysteine residues involved in disulfide bridges are highlighted in cyan.