Fig. 2
From: Kiwi genome provides insights into evolution of a nocturnal lifestyle
Protein sequence comparison revealed substitutions of Glu3.49 to Lys (E/DRY motif) and Glu6.30 to Gly in kiwi OPN1MW (RH2) and kiwi OPN1SW, respectively. Both residues are 100 % conserved in all birds sequenced so far and over 100 publicly available sequences of other vertebrate OPN1MW and OPN1SW orthologs. To assure the OPN1MW-change is kiwi-specific additional ratites were sequenced, including different kiwi species and the extinct moa. Glu3.49 of the E/DRY motif and Glu6.30 at the N-terminal end of helix 6 are parts of an ‘ionic lock’ interhelical hydrogen-bond network which is highly conserved in many rhodopsin-like GPCRs. Nb – North Island brown kiwi, Ob – Okarito brown kiwi, Gs – Great spotted kiwi, Ec – Emeus crassus (Eastern moa), Pg – Pachyornis geranoides (Mappin’s moa), Chuck-will – Chuck-will’s-widow