title: Purification and characterization of 2,4-dichlorophenol hydroxylase isolated from a bacterium of the alpha-2 subgroup of the Proteobacteria.
abstract: 2,4-Dichlorophenol hydroxylase (EC 1.14.13.20) was purified to apparent homogeneity from the bacterial strain S1, a member of the alpha-2 subgroup of the Proteobacteria. The molecular masses of the native enzyme and the subunit were determined to be 256 and 64 kDa, respectively, suggesting a homotetrameric structure. The enzyme converted 2,4-dichlorophenol to 3,5-dichlorocatechol. The apparent K(m) values for 2,4-dichlorophenol, NADPH and NADH were 3, 240 and 420 microM, respectively. The enzyme hydroxylated a broad range of halogenated phenols. 3-Chloro-, 2,6-dichloro- and 2,4,6-trichlorophenol acted as 'non-substrate' effectors. The N-terminal sequence revealed 72% identity with the amino acid sequence deduced from the pJP4-encoded tfdB gene.
authors.affiliation: Institut für Mikrobiologie, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Makdessi
authors.forename: U
authors.initials: U
authors.lastname: Lechner
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification; D002733:Chlorophenols / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D006899:Mixed Function Oxygenases / Q000032:analysis / Q000235:genetics* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D012230:Rhizobiaceae / Q000201:enzymology* / Q000235:genetics*; D012722:Sewage / Q000382:microbiology; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D002733:Chlorophenols; D012722:Sewage; D006899:Mixed Function Oxygenases; C034354:2,4-dichlorophenol hydroxylase