Figure 1.

Final sequence alignment for TM1–7 and ECL2 of bovine rhodopsin (bRho) and the hDOR used to build the receptor model. Vertical lines correspond to an alignment of identical residues, and the dots indicate degrees of similarity between aligned residues. Sequence similarities for the above fragments are 38% (TM1), 34% (TM2), 49% (TM3), 39% (TM4), 60% (TM5), 55% (TM6), 41% (TM7), and 33% (ECL2). The most conserved residue between all GPCRs in each helix is underlined (Ballesteros and Weinstein 1995). The highlighted residues (C121, D128, R192, C198, and Y308) are conserved among all the known opioid receptors and are of particular interest to this study.