ID 1.17.99.10 DE steroid C-25 hydroxylase. AN cholesterol C-25 dehydrogenase. AN steroid C-25 dehydrogenase. CA A + cholest-4-en-3-one + H2O = 25-hydroxycholest-4-en-3-one + AH2. CC -!- The enzyme, characterized from the bacterium Sterolibacterium CC denitrificans, participates in the anaerobic degradation of CC cholesterol. CC -!- The enzyme can accept several substrates including vitamin D3. CC -!- The enzyme contains a bis(guanylyl molybdopterin) cofactor, five CC [Fe-S] clusters, and one heme b. cf. EC 1.14.99.38. //