Retinoid isomerohydrolase (RPE65)

Critical isomerohydrolase in the retinoid cycle involved in regeneration of 11-cis-retinal, the chromophore of rod and cone opsins. Catalyzes the cleavage and isomerization of all-trans- retinyl fatty acid esters into 11-cis-retinol which is further oxidized by 11-cis retinol dehydrogenase to 11-cis-retinal for use as visual chromophore (PubMed:16116091).

Also capable of catalyzing the isomerization of lutein into meso-zeaxanthin an eye-specific carotenoid (PubMed:28874556). The soluble form binds vitamin A (all-trans- retinol), making it available for LRAT processing to all-trans- retinyl ester.