Reaction: 4-aminobenzoate + reduced acceptor + 2 O2 = 4-nitrobenzoate + acceptor + 2 H2O
Glossary: aureothin = 2-methoxy-3,5-dimethyl-6-[(2R,4Z)-4-[(2E)-2-methyl-3-(4-nitrophenyl)prop-2-en-1-ylidene]oxolan-2-yl]-4H-pyran-4-one
Other name(s): aurF (gene name)
Systematic name: 4-aminobenzoate,acceptor:oxygen oxidoreductase (N-hydroxylating)
Comments: 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 1.14.99.67, N-[1-(4-aminophenyl)-1,3-dihydroxypropan-2-yl]-2,2-dichloroacetamide N-oxygenase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:
References:
1. He, J. and 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 (2004) 3694-3695. [PMID: 15038705]
2. Lee, J. and 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 (2006) 622-625. [PMID: 16342311]
3. Zocher, G., Winkler, R., Hertweck, C. and Schulz, G.E. Structure and action of the N-oxygenase AurF from Streptomyces thioluteus. J. Mol. Biol. 373 (2007) 65-74. [PMID: 17765264]
4. Choi, Y.S., Zhang, H., Brunzelle, J.S., Nair, S.K. and Zhao, H. In vitro reconstitution and crystal structure of p-aminobenzoate N-oxygenase (AurF) involved in aureothin biosynthesis. Proc. Natl. Acad. Sci. USA 105 (2008) 6858-6863. [PMID: 18458342]
5. Korboukh, V.K., Li, N., Barr, E.W., Bollinger, J.M., Jr. and Krebs, C. A long-lived, substrate-hydroxylating peroxodiiron(III/III) intermediate in the amine oxygenase, AurF, from Streptomyces thioluteus. J. Am. Chem. Soc. 131 (2009) 13608-13609. [PMID: 19731912]
6. Li, N., Korboukh, V.K., Krebs, C. and Bollinger, J.M., Jr. Four-electron oxidation of p-hydroxylaminobenzoate to p-nitrobenzoate by a peroxodiferric complex in AurF from Streptomyces thioluteus. Proc. Natl. Acad. Sci. USA 107 (2010) 15722-15727. [PMID: 20798054]