Acyl-CoA reductase, LuxC, (EC=1.2.1.50) is the fatty acid reductase enzyme responsible for synthesis of the aldehyde substrate for the luminescent reaction catalyzed by luciferase. The fatty acid reductase, a luminescence-specific, multienzyme complex (LuxCDE), reduces myristic acid to generate the long chain fatty aldehyde required for the luciferase-catalyzed reaction resulting in the emission of blue-green light. Mutational studies of conserved cysteines of LuxC revealed that the cysteine which aligns with the catalytic cysteine conserved throughout the ALDH superfamily is the LuxC acylation site. This CD is composed of mainly bacterial sequences but also includes a few archaeal sequences similar to the Methanospirillum hungateiacyl acyl-CoA reductase RfbN.
Comment:this cysteine is the site of acylation of the Lux-specific fatty acyl-CoA reductase and aligns with to the catalytic cysteine of NAD(P)+-dependent, aldehyde dehydrogenases.
Jiyao W et al.(2023). "The conserved domain database in 2023.",