all-trans-beta-carotene + AH2 + O2 = 4-hydroxy-all-trans-beta-carotene + A + H2O
all-trans-beta-carotene + ah2 + o2 = 4-hydroxy-all-trans-beta-carotene + a + h2o
all-trans-beta-carotene + AH2 + O2 = 4-hydroxy-all-trans-beta-carotene + A + H2O
all-trans-beta-carotene + ah2 + o2 = 4-hydroxy-all-trans-beta-carotene + a + h2o