ID 1.13.11.63 DE beta-carotene 15,15'-dioxygenase. AN beta-carotene 15,15'-monooxygenase. AN carotene 15,15'-dioxygenase. AN carotene dioxygenase. CA all-trans-beta-carotene + O2 = 2 all-trans-retinal. CC -!- Requires Fe(2+). CC -!- The enzyme cleaves beta-carotene symmetrically, producing two CC molecules of all-trans-retinal. CC -!- Both atoms of the oxygen molecule are incorporated into the products. CC -!- The enzyme can also process beta-cryptoxanthin, 8'-apo-beta- CC carotenal, 4'-apo-beta-carotenal, alpha-carotene and gamma-carotene CC in decreasing order. CC -!- The presence of at least one unsubstituted beta-ionone ring in a CC substrate greater than C30 is mandatory. CC -!- A prokaryotic enzyme has been reported from the uncultured marine CC bacterium 66A03, where it is involved in the proteorhodopsin system, CC which uses retinal as its chromophore. CC -!- Formerly EC 1.13.11.21, EC 1.13.11.n2 and EC 1.14.99.36. DR Q9I993, BCDO1_CHICK; Q9HAY6, BCDO1_HUMAN; Q9JJS6, BCDO1_MOUSE; DR Q91XT5, BCDO1_RAT ; Q9HNE6, BLH_HALSA ; Q4PNI0, BLH_UNCMB ; DR B0R5N7, BRP_HALS3 ; Q9HPU7, BRP_HALSA ; S0ENQ2, CARX_GIBF5 ; //