Fig. 3.

Schematic diagram of the human red and green pigments in the membrane. The N terminus (N) faces the extracellular space, and the C terminus (C) faces the cytosol. Eachfilled circle represents a position that differs between red and green pigments in the set of sequences studied here; these are positions 65, 111, 116, 153, 171, 174, 178, 180, 230, 233, 236, 249, 274, 275, 277, 279, 285, 298, and 309. The locations of lysine³¹² (K312), the site of covalent attachment of 11-cis retinal, and the polymorphic serine/alanine at position 180 (A180/S180) are indicated. The five intron positions are indicated byvertical arrows.