This enzyme catalyses the following chemical reaction This is a cleavage reaction which cleaves β-carotene, utilizes molecular oxygen, is enhanced by the presence of bile salts and thyroxine, and generates two molecules of retinal.
[7] The dioxygenase also asymmetrically cleaves beta-cryptoxanthin, trans-β-apo-8'-carotenal, beta-4'-apo-β-carotenal, alpha-carotene and gamma-carotene in decreasing order, creating one retinal molecule, all of these being substrates with a carbon chain greater than C30, with at least one unsubstituted β-ionone ring.
[8] This enzyme belongs to the (enzymatically-defined) family of oxidoreductases, specifically those acting on paired donors, with O2 as oxidant and incorporation or reduction of oxygen.
[11] Beta-carotene 15,15'-dioxygenase belongs to the (similarity-defined) family of carotenoid oxygenases (InterPro: IPR004294).
Enzymes of this family contain a Fe2+ active site, coordinated usually by four His residues.