3-Hydroxylaminophenol Mutase from Ralstonia eutropha JMP134 Catalyzes a Bamberger Rearrangement
AUTOR(ES)
Schenzle, Andreas
FONTE
American Society for Microbiology
RESUMO
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.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=93532Documentos Relacionados
- Whole-Cell Kinetics of Trichloroethylene Degradation by Phenol Hydroxylase in a Ralstonia eutropha JMP134 Derivative
- Genetic and Biochemical Characterization of a 2,4,6-Trichlorophenol Degradation Pathway in Ralstonia eutropha JMP134
- Chemoselective Nitro Group Reduction and Reductive Dechlorination Initiate Degradation of 2-Chloro-5-Nitrophenol by Ralstonia eutropha JMP134
- Importance of Different tfd Genes for Degradation of Chloroaromatics by Ralstonia eutropha JMP134†
- Chemotaxis of Ralstonia eutropha JMP134(pJP4) to the Herbicide 2,4-Dichlorophenoxyacetate