title: Reaction mechanism of flavin-dependent hydroxylation. Evolution of a non-imitable enzyme.
abstract: Analysis of the partially refined X-ray crystallographic structure of the active site of p-hydroxybenzoate hydroxylase shows clearly that the enzyme is complementary to a flavin C4,C4a-dioxetane derivative. A mechanism is proposed based on such an intermediate as the oxenoid transferring agent. A non-enzymatic analogue of this reaction is not known in organic chemistry. A possible evolutionary pathway for such a non-imitable enzyme is discussed.
mesh_terms: D015109:4-Hydroxybenzoate-3-Monooxygenase / Q000378:metabolism*; D001665:Binding Sites; D005075:Biological Evolution; D002384:Catalysis; D055598:Chemical Phenomena; D002621:Chemistry; D005415:Flavins / Q000502:physiology*; D006900:Hydroxylation; D006899:Mixed Function Oxygenases / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
chemical_list: D005415:Flavins; D006899:Mixed Function Oxygenases; D015109:4-Hydroxybenzoate-3-Monooxygenase