Fig. 5.

Conservation of ligand-contacting residues. The conservation indices (CI) of ligand-contacting residues across the aminergic receptors and within the indicated subfamilies and subgroups are calculated by the ProperTM server (Shi et al., 2001; Beuming and Weinstein, 2004). The positions with low sequence conservation are indicated by filled colors (CI values ≤ 0.25 in light blue, and those between 0.25 and 0.50 in light green). The highly conserved positions among all amine receptors with CI > 0.75 are highlighted in red. Note, at the aminergic receptor family level, except for Asp^3.32, Trp^6.48, Tyr/Trp^7.43, other OBS positions are not more conserved than SBP positions.