Enzymes
UniProtKB help_outline | 1 proteins |
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- Name help_outline 4-aminobenzoate Identifier CHEBI:17836 (Beilstein: 3904778; CAS: 2906-28-7) help_outline Charge -1 Formula C7H6NO2 InChIKeyhelp_outline ALYNCZNDIQEVRV-UHFFFAOYSA-M SMILEShelp_outline Nc1ccc(cc1)C([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 10 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline AH2 Identifier CHEBI:17499 Charge 0 Formula RH2 SMILEShelp_outline *([H])[H] 2D coordinates Mol file for the small molecule Search links Involved in 2,713 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline O2 Identifier CHEBI:15379 (CAS: 7782-44-7) help_outline Charge 0 Formula O2 InChIKeyhelp_outline MYMOFIZGZYHOMD-UHFFFAOYSA-N SMILEShelp_outline O=O 2D coordinates Mol file for the small molecule Search links Involved in 2,648 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline 4-nitrobenzoate Identifier CHEBI:142863 Charge -1 Formula C7H4NO4 InChIKeyhelp_outline OTLNPYWUJOZPPA-UHFFFAOYSA-M SMILEShelp_outline C1=C(C([O-])=O)C=CC(=C1)[N+]([O-])=O 2D coordinates Mol file for the small molecule Search links Involved in 1 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline A Identifier CHEBI:13193 Charge Formula R SMILEShelp_outline * 2D coordinates Mol file for the small molecule Search links Involved in 2,783 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
- Name help_outline H2O Identifier CHEBI:15377 (Beilstein: 3587155; CAS: 7732-18-5) help_outline Charge 0 Formula H2O InChIKeyhelp_outline XLYOFNOQVPJJNP-UHFFFAOYSA-N SMILEShelp_outline [H]O[H] 2D coordinates Mol file for the small molecule Search links Involved in 6,048 reaction(s) Find molecules that contain or resemble this structure Find proteins in UniProtKB for this molecule
Cross-references
RHEA:58888 | RHEA:58889 | RHEA:58890 | RHEA:58891 | |
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Publications
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A long-lived, substrate-hydroxylating peroxodiiron(III/III) intermediate in the amine oxygenase, AurF, from Streptomyces thioluteus.
Korboukh V.K., Li N., Barr E.W., Bollinger J.M. Jr., Krebs C.
The amine oxygenase AurF from Streptomyces thioluteus catalyzes the six-electron oxidation of p-aminobenzoate (pABA) to p-nitrobenzoate (pNBA). In this work, we have studied the reaction of its reduced Fe(2)(II/II) cofactor with O(2), which results in generation of a peroxo-Fe(2)(III/III) intermed ... >> More
The amine oxygenase AurF from Streptomyces thioluteus catalyzes the six-electron oxidation of p-aminobenzoate (pABA) to p-nitrobenzoate (pNBA). In this work, we have studied the reaction of its reduced Fe(2)(II/II) cofactor with O(2), which results in generation of a peroxo-Fe(2)(III/III) intermediate. In the absence of substrate, this intermediate is unusually stable (t(1/2) = 7 min at 20 degrees C), allowing for its accumulation to almost stoichiometric amounts. Its decay is accelerated approximately 10(5)-fold by the substrate, pABA, implying that it is the complex that effects the two-electron oxidation of the amine to the hydroxylamine. The nearly quantitative conversion of pABA to pNBA by solutions containing an excess of the intermediate suggests that it may also be competent for the two subsequent two-electron oxidations leading to the product. << Less
J. Am. Chem. Soc. 131:13608-13609(2009) [PubMed] [EuropePMC]
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Mechanistic studies on the conversion of arylamines into arylnitro compounds by aminopyrrolnitrin oxygenase: identification of intermediates and kinetic studies.
Lee J., Zhao H.
Angew. Chem. Int. Ed. 45:622-625(2006) [PubMed] [EuropePMC]
This publication is cited by 1 other entry.
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In vitro reconstitution and crystal structure of p-aminobenzoate N-oxygenase (AurF) involved in aureothin biosynthesis.
Choi Y.S., Zhang H., Brunzelle J.S., Nair S.K., Zhao H.
p-Aminobenzoate N-oxygenase (AurF) from Streptomyces thioluteus catalyzes the formation of unusual polyketide synthase starter unit p-nitrobenzoic acid (pNBA) from p-aminobenzoic acid (pABA) in the biosynthesis of antibiotic aureothin. AurF is a metalloenzyme, but its native enzymatic activity has ... >> More
p-Aminobenzoate N-oxygenase (AurF) from Streptomyces thioluteus catalyzes the formation of unusual polyketide synthase starter unit p-nitrobenzoic acid (pNBA) from p-aminobenzoic acid (pABA) in the biosynthesis of antibiotic aureothin. AurF is a metalloenzyme, but its native enzymatic activity has not been demonstrated in vitro, and its catalytic mechanism is unclear. In addition, the nature of the cofactor remains a controversy. Here, we report the in vitro reconstitution of the AurF enzyme activity, the crystal structure of AurF in the oxidized state, and the cocrystal structure of AurF with its product pNBA. Our combined biochemical and structural analysis unequivocally indicates that AurF is a non-heme di-iron monooxygenase that catalyzes sequential oxidation of aminoarenes to nitroarenes via hydroxylamine and nitroso intermediates. << Less
Proc. Natl. Acad. Sci. U.S.A. 105:6858-6863(2008) [PubMed] [EuropePMC]
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Four-electron oxidation of p-hydroxylaminobenzoate to p-nitrobenzoate by a peroxodiferric complex in AurF from Streptomyces thioluteus.
Li N., Korboukh V.K., Krebs C., Bollinger J.M. Jr.
The nonheme di-iron oxygenase, AurF, converts p-aminobenzoate (Ar-NH(2), where Ar = 4-carboxyphenyl) to p-nitrobenzoate (Ar-NO(2)) in the biosynthesis of the antibiotic, aureothin, by Streptomyces thioluteus. It has been reported that this net six-electron oxidation proceeds in three consecutive, ... >> More
The nonheme di-iron oxygenase, AurF, converts p-aminobenzoate (Ar-NH(2), where Ar = 4-carboxyphenyl) to p-nitrobenzoate (Ar-NO(2)) in the biosynthesis of the antibiotic, aureothin, by Streptomyces thioluteus. It has been reported that this net six-electron oxidation proceeds in three consecutive, two-electron steps, through p-hydroxylaminobenzoate (Ar-NHOH) and p-nitrosobenzoate (Ar-NO) intermediates, with each step requiring one equivalent of O(2) and two exogenous reducing equivalents. We recently demonstrated that a peroxodiiron(III/III) complex (peroxo--AurF) formed by addition of O(2) to the diiron(II/II) enzyme ( -AurF) effects the initial oxidation of Ar-NH(2), generating a mu-(oxo)diiron(III/III) form of the enzyme (mu-oxo- -AurF) and (presumably) Ar-NHOH. Here we show that peroxo--AurF also oxidizes Ar-NHOH. Unexpectedly, this reaction proceeds through to the Ar-NO(2) final product, a four-electron oxidation, and produces -AurF, with which O(2) can combine to regenerate peroxo--AurF. Thus, conversion of Ar-NHOH to Ar-NO(2) requires only a single equivalent of O(2) and (starting from -AurF or peroxo--AurF) is fully catalytic in the absence of exogenous reducing equivalents, by contrast to the published stoichiometry. This novel type of four-electron N-oxidation is likely also to occur in the reaction sequences of nitro-installing di-iron amine oxygenases in the biosyntheses of other natural products. << Less
Proc. Natl. Acad. Sci. U.S.A. 107:15722-15727(2010) [PubMed] [EuropePMC]
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Structure and action of the N-oxygenase AurF from Streptomyces thioluteus.
Zocher G., Winkler R., Hertweck C., Schulz G.E.
Nitro groups are found in a number of bioactive compounds. Most of them arise by a stepwise mono-oxygenation of amino groups. One of the involved enzymes is AurF participating in the biosynthesis of aureothin. Its structure was established at 2.1 A resolution showing a homodimer with a binuclear m ... >> More
Nitro groups are found in a number of bioactive compounds. Most of them arise by a stepwise mono-oxygenation of amino groups. One of the involved enzymes is AurF participating in the biosynthesis of aureothin. Its structure was established at 2.1 A resolution showing a homodimer with a binuclear manganese cluster. The enzyme preparation, which yielded the analyzed crystals, showed activity using in vitro and in vivo assays. Chain fold and cluster are homologous with ribonucleotide reductase subunit R2 and related enzymes. The two manganese ions and an iron content of about 15% were established by anomalous X-ray diffraction. A comparison of the cluster with more common di-iron clusters suggested an additional histidine in the coordination sphere to cause the preference for manganese over iron. There is no oxo-bridge. The substrate p-amino-benzoate was modeled into the active center. The model is supported by mutant activity measurements. It shows the geometry of the reaction and explains the established substrate spectrum. << Less
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Biosynthetic origin of the rare nitroaryl moiety of the polyketide antibiotic aureothin: involvement of an unprecedented N-oxygenase.
He J., Hertweck C.
The antibiotic aureothin is a rare natural nitroaromatic compound produced by Streptomyces thioluteus. By labeling experiments, we demonstrate for the first time that p-nitrobenzoate (PNBA) serves as a polyketide synthase starter unit. Cloning, heterologous expression, and inactivation experiments ... >> More
The antibiotic aureothin is a rare natural nitroaromatic compound produced by Streptomyces thioluteus. By labeling experiments, we demonstrate for the first time that p-nitrobenzoate (PNBA) serves as a polyketide synthase starter unit. Cloning, heterologous expression, and inactivation experiments reveal that this unusual primer is synthesized from p-aminobenzoate (PABA) by means of AurF, a novel N-oxygenase. << Less