Fig 1. Multiple sequence alignment of representative aminergic receptors and selected TAARs from different organisms.

Positions that are at least 30% or 95% conserved are highlighted in gray and black, respectively. Highly conserved residues in the class A GPCR family are indicated by the Ballesteros-Weinstein numbering (X.50 of helix X), as well as the conserved cysteines involved in disulfide bridges (in yellow). Residues at position 3.32 and 5.42/5.43 are highlighted in red. Non-conserved N-, C- terminal and ICL3 amino acid sequences are omitted from the figure. Acronyms: h5HT1B (human 5-hydroxytryptamine receptor 1B), hH1R (human histamine receptor H1), hD3R (human dopamine receptor D3), hADRB2 (human β₂-adrenergic receptor), hTAAR6 (human trace-amine associated receptor 6), hTAAR8 (human trace-amine associated receptor 8), mTAAR6 (mouse trace-amine associated receptor 6), mTAAR8b (mouse trace-amine associated receptor 8b), rTAAR6 (rat trace-amine associated receptor 6), rTAAR8a (rat trace-amine associated receptor 8a), zTAAR13c (zebrafish trace-amine associated receptor 13c) and zTAAR13d (zebrafish trace-amine associated receptor 13d).