An organic O donor for biological hydroxylation reactions
Katayoun Kazemzadeh Ferizhendi, Philippe Simon, Ludovic Pelosi, Emmanuel Séchet, Roache Arulanandam, Mahmoud Hajj Chehade, Martial Rey, Deniz Onal, Laura Flandrin, Rouba Chreim, Bruno Faivre, Samuel Chau-Duy-Tam Vo, Rodrigo Arias-Cartin, Frédéric Barras, Marc Fontecave, Emmanuelle Bouveret, Murielle Lombard, Fabien Pierrel- Multidisciplinary
All biological hydroxylation reactions are thought to derive the oxygen atom from one of three inorganic oxygen donors, O 2 , H 2 O 2, or H 2 O. Here, we have identified the organic compound prephenate as the oxygen donor for the three hydroxylation steps of the O 2 -independent biosynthetic pathway of ubiquinone, a widely distributed lipid coenzyme. Prephenate is an intermediate in the aromatic amino acid pathway and genetic experiments showed that it is essential for ubiquinone biosynthesis in Escherichia coli under anaerobic conditions. Metabolic labeling experiments with 18 O-shikimate, a precursor of prephenate, demonstrated the incorporation of 18 O atoms into ubiquinone. The role of specific iron–sulfur enzymes belonging to the widespread U32 protein family is discussed. Prephenate-dependent hydroxylation reactions represent a unique biochemical strategy for adaptation to anaerobic environments.