EC - 4-aminobenzoate N-oxygenase

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IntEnz Enzyme Nomenclature


Accepted name:
4-aminobenzoate N-oxygenase
Systematic name:
4-aminobenzoate,acceptor:oxygen oxidoreductase (N-hydroxylating)



The enzyme, characterized from the bacterium Streptomyces thioluteus, catalyses an early step in the biosynthesis of the antibiotic aureothin. It contains a carboxylate-bridged binuclear non-heme iron cluster. The native electron donor has not been identified, but is likely an iron-sulfur protein. The reaction mechanism involves formation of an extremely stable peroxo intermediate that catalyses three two-electron oxidations via a hydroxylamine and dihydroxylamine intermediates. cf. EC, N-[1-(4-aminophenyl)-1,3-dihydroxypropan-2-yl]-2,2-dichloroacetamide N-oxygenase.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB


  1. He, J., Hertweck, C.
    Biosynthetic origin of the rare nitroaryl moiety of the polyketide antibiotic aureothin: involvement of an unprecedented N-oxygenase.
    J. Am. Chem. Soc. 126 : 3694-3695 (2004). [PMID: 15038705]
  2. Lee, J., Zhao, H.
    Mechanistic studies on the conversion of arylamines into arylnitro compounds by aminopyrrolnitrin oxygenase: identification of intermediates and kinetic studies.
    Angew. Chem. Int. Ed. Engl. 45 : 622-625 (2006). [PMID: 16342311]
  3. Zocher, G., Winkler, R., Hertweck, C., Schulz, G. E.
    Structure and action of the N-oxygenase AurF from Streptomyces thioluteus.
    J. Mol. Biol. 373 : 65-74 (2007). [PMID: 17765264]
  4. Choi, Y. S., Zhang, H., Brunzelle, J. S., Nair, S. K., Zhao, H.
    In vitro reconstitution and crystal structure of p-aminobenzoate N-oxygenase (AurF) involved in aureothin biosynthesis.
    Proc Natl Acad Sci U S A 105 : 6858-6863 (2008). [PMID: 18458342]
  5. Korboukh, V. K., Li, N., Barr, E. W., Bollinger, J. M., Krebs, C.
    A long-lived, substrate-hydroxylating peroxodiiron(III/III) intermediate in the amine oxygenase, AurF, from Streptomyces thioluteus.
    J Am Chem Soc 131 : 13608-13609 (2009). [PMID: 19731912]
  6. Li, N., Korboukh, V. K., Krebs, C., Bollinger, J. M.
    Four-electron oxidation of p-hydroxylaminobenzoate to p-nitrobenzoate by a peroxodiferric complex in AurF from Streptomyces thioluteus.
    Proc Natl Acad Sci U S A 107 : 15722-15727 (2010). [PMID: 20798054]

[EC created 2020]