Alignment of deduced amino acid sequences for Terebratalia c-opsin and representative opsins from other taxa. Consensus amino acids (>50%) for the alignment of all opsins are shaded grey. Consensus amino acids only for the alignment of c-opsins are shaded green. In some cases the consensus residue for c-opsins differs than that for all opsins. C-opsins have a purple background, r-opsins have an orange background, and ourgroup opsins have a white background. A red bar highlights the conserved C-terminal motif of c-opsins. Transmembrane helices I-VII are marked with black horizontal lines. (‡) marks the position of the glutamate counterion and (◊) marks the conserved lysine that forms a Schiff base with retinal to form rhodopsin.