Broad specificity mitochondrial dioxygenase that mediates the asymmetric oxidative cleavage of carotenoids. Cleaves carotenes (pure hydrocarbon carotenoids) such as all-trans-beta-carotene and lycopene as well as xanthophylls (oxygenated carotenoids) such as zeaxanthin, lutein and beta-cryptoxanthin at both the 9,10 and the 9',10' carbon-carbon double bond. Through its function in carotenoids metabolism regulates oxidative stress and the production of important signaling molecules. all-trans-beta-carotene + O2 = all-trans-10'-apo-beta-carotenal + beta-ionone 5-cis-lycopene + O2 = (3E,5E)-6,10-dimethylundeca-3,5,9-trien-2-one + 5-cis-10'-apo-lycopenal 13-cis-lycopene + O2 = (3E,5E)-6,10-dimethylundeca-3,5,9-trien-2-one + 13-cis-10'-apo-lycopenal lutein + O2 = (3R)-3-hydroxy-10'-apo-beta-carotenal + (3R,6R)-hydroxy-alpha-ionone lutein + O2 = (3R)-hydroxy-beta-ionone + (3R,6R)-3-hydroxy-10'-apo-alpha-carotenal all-trans-zeaxanthin + 2 O2 = 2 (3R)-hydroxy-beta-ionone + 4,9-dimethyldodeca-2,4,6,8,10-pentaenedial all-trans-zeaxanthin + O2 = (3R)-3-hydroxy-10'-apo-beta-carotenal + (3R)-hydroxy-beta-ionone beta-cryptoxanthin + O2 = (3R)-hydroxy-beta-ionone + all-trans-10'-apo-beta-carotenal all-trans-10'-apo-beta-carotenal + O2 = 4,9-dimethyldodeca-2,4,6,8,10-pentaenedial + beta-ionone (3R)-3-hydroxy-10'-apo-beta-carotenal + O2 = (3R)-hydroxy-beta-ionone + 4,9-dimethyldodeca-2,4,6,8,10-pentaenedial (3R,6R)-3-hydroxy-10'-apo-alpha-carotenal + O2 = (3R,6R)-hydroxy-alpha-ionone + 4,9-dimethyldodeca-2,4,6,8,10-pentaenedial Binds 1 Fe(2+) ion per subunit. Highly expressed in retinal pigment epithelium. Also expressed in stomach, small intestine, liver, testis, kidney, adrenal gland, pancreas, heart, skeletal muscle and prostate (at protein level). Belongs to the carotenoid oxygenase family. Truncated N-terminus.