3-Hydroxylaminophenol mutase from Ralstonia eutropha JMP134 catalyzes a Bamberger rearrangement.
3-Hydroxylaminophenol mutase from Ralstonia eutropha JMP134 is involved in the degradative pathway of 3-nitrophenol, in which it catalyzes the conversion of 3-hydroxylaminophenol to aminohydroquinone. To show that the reaction was really catalyzed by a single enzyme without the release of intermediates, the corresponding protein was purified to apparent homogeneity from an extract of cells grown on 3-nitrophenol as the nitrogen source and succinate as the carbon and energy source. 3-Hydroxylaminophenol mutase appears to be a relatively hydrophobic but soluble and colorless protein consisting of a single 62-kDa polypeptide. The pI was determined to be at pH 4.5. In a database search, the NH2-terminal amino acid sequence of the undigested protein and of two internal sequences of 3-hydroxylaminophenol mutase were found to be most similar to those of glutamine synthetases from different species. Hydroxylaminobenzene, 4-hydroxylaminotoluene, and 2-chloro-5-hydroxylaminophenol, but not 4-hydroxylaminobenzoate, can also serve as substrates for the enzyme. The enzyme requires no oxygen or added cofactors for its reaction, which suggests an enzymatic mechanism analogous to the acid-catalyzed Bamberger rearrangement.
Schenzle
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Fraunhofer Institut für Grenzflächen- und Bioverfahrenstechnik, D-70569 Stuttgart, Germany.
Lenke
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Spain
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JC
Knackmuss
H J
HJ
D000595:Amino Acid Sequence; D001419:Bacteria / Q000201:enzymology; D002846:Chromatography, Affinity; D002848:Chromatography, DEAE-Cellulose; D020118:Cupriavidus necator / Q000201:enzymology* / Q000254:growth & development; D004591:Electrophoresis, Polyacrylamide Gel; D005974:Glutamate-Ammonia Ligase / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D019751:Intramolecular Transferases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D007700:Kinetics; D008956:Models, Chemical; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009596:Nitrophenols / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014461:Ultracentrifugation
D009596:Nitrophenols; D019751:Intramolecular Transferases; C118129:3-hydroxylaminophenol mutase; D005974:Glutamate-Ammonia Ligase; C049017:3-nitrophenol