Structural differences and differential expression among rhabdomeric opsins reveal functional change after gene duplication in the bay scallop, Argopecten irradians (Pectinidae)

Table 2 Sequence and structural motifs in scallop (Air) and squid (Tpa) G_q-opsins

Motifs	Air-OPNGq1 493 aa	Air-OPNGq2 456 aa	Air-OPNGq3 519 aa	Air-OPNGq4 481 aa	Tpa-OPNGq1 448 aa
LxxxD TMII (pos 76–80)	LAVSD	LALSD	LALSD	LALSD	LAFSD
Disulfide bond	C108, C186	C108, C186	C108, C186	C108, C186	C108, C186
Hydrogen bond with Schiff base	N87, Y111	N87, Y111	N87, Y111	N87, Y111	N87, Y111
E/DRY TMIII (pos 132–134)	DRY	DRC	DRF	DRF	DRY
Counterion	E180	E180	E180	E180	E180
LAK TMVII (pos 305–307)	LAK	LAK	LAK	LAK	FAK
NPxxY TMVII (pos 311–315)	NPIIY	NPIVY	NPIVY	NPLVY	NPMIY
G-protein binding (pos 319–321)	HPK	HPK	HPK	HPR	HPK

The amino acid numbering system follows the amino acid position (pos) of squid rhodopsin

ISSN: 2730-7182