Publications

• Crystal structure of the hydroxyquinol 1,2-dioxygenase from Nocardioides simplex 3E, a key enzyme involved in polychlorinated aromatics biodegradation.

  Ferraroni M., Seifert J., Travkin V.M., Thiel M., Kaschabek S., Scozzafava A., Golovleva L., Schloemann M., Briganti F.

  Hydroxyquinol 1,2-dioxygenase (1,2-HQD) catalyzes the ring cleavage of hydroxyquinol (1,2,4-trihydroxybenzene), a central intermediate in the degradation of aromatic compounds including a variety of particularly recalcitrant polychloro- and nitroaromatic pollutants. We report here the primary sequ ... >> More

  Hydroxyquinol 1,2-dioxygenase (1,2-HQD) catalyzes the ring cleavage of hydroxyquinol (1,2,4-trihydroxybenzene), a central intermediate in the degradation of aromatic compounds including a variety of particularly recalcitrant polychloro- and nitroaromatic pollutants. We report here the primary sequence determination and the analysis of the crystal structure of the 1,2-HQD from Nocardioides simplex 3E solved at 1.75 A resolution using the multiple wavelength anomalous dispersion of the two catalytic irons (1 Fe/293 amino acids). The catalytic Fe(III) coordination polyhedron composed by the side chains of Tyr164, Tyr197, His221, and His223 resembles that of the other known intradiol-cleaving dioxygenases, but several of the tertiary structure features are notably different. One of the most distinctive characteristics of the present structure is the extensive openings and consequent exposure to solvent of the upper part of the catalytic cavity arranged to favor the binding of hydroxyquinols but not catechols. A co-crystallized benzoate-like molecule is also found bound to the metal center forming a distinctive hydrogen bond network as observed previously also in 4-chlorocatechol 1,2-dioxygenase from Rhodococcus opacus 1CP. This is the first structure of an intradiol dioxygenase specialized in hydroxyquinol ring cleavage to be investigated in detail. << Less

  J. Biol. Chem. 280:21144-21154(2005) [PubMed] [EuropePMC]

• Properties of salicylate hydroxylase and hydroxyquinol 1,2-dioxygenase purified from Trichosporon cutaneum.

  Sze I.S., Dagley S.

  Salicylate hydroxylase (salicylate 1-monooxygenase, EC 1.14.13.1) was purified from the soil yeast Trichosporon cutaneum. The enzyme contained flavin adenine dinucleotide and was monomeric, with a molecular weight of 45,300. In addition to salicylate, the four isomeric dihydroxybenzoates having on ... >> More

  Salicylate hydroxylase (salicylate 1-monooxygenase, EC 1.14.13.1) was purified from the soil yeast Trichosporon cutaneum. The enzyme contained flavin adenine dinucleotide and was monomeric, with a molecular weight of 45,300. In addition to salicylate, the four isomeric dihydroxybenzoates having one hydroxyl adjacent to carboxyl in the benzene nucleus were oxidatively decarboxylated without formation of hydrogen peroxide. One of these isomers, gentisate, was rapidly oxidized to hydroxyquinol by the enzyme but did not serve as an effective single carbon source for T. cutaneum; however, when growing with salicylate, cells also readily utilized gentisate for growth. Hydroxyquinol 1,2-dioxygenase (EC 1.13.11....) is a newly investigated enzyme which was purified from T. cutaneum grown with 4-hydroxybenzoate. The enzyme was red, contained ferric iron, and was specific for hydroxyquinol; catechol and pyrogallol were oxidized at less than 1% of the rate for hydroxyquinol, and no activity could be detected against seven other catechols. The enzyme was composed of two nonidentical subunits having molecular weights of 39,600 and 38,200 and was apparently dimeric. << Less

  J Bacteriol 159:353-359(1984) [PubMed] [EuropePMC]

• Cloning and sequence analysis of hydroxyquinol 1,2-dioxygenase gene in 2,4,6-trichlorophenol-degrading Ralstonia pickettii DTP0602 and characterization of its product.

  Hatta T., Nakano O., Imai N., Takizawa N., Kiyohara H.

  A gene encoding hydroxyquinol 1,2-dioxygenase was cloned from 2,4,6-trichlorophenol-degrading Ralstonia (Pseudomonas) pickettii strain DTP0602. Cell-free extracts of Escherichia coli containing a cloned 1.4-kb StuI-XhoI DNA fragment of R. pickettii DTP0602 hydroxyquinol 1,2-dioxygenase converted h ... >> More

  A gene encoding hydroxyquinol 1,2-dioxygenase was cloned from 2,4,6-trichlorophenol-degrading Ralstonia (Pseudomonas) pickettii strain DTP0602. Cell-free extracts of Escherichia coli containing a cloned 1.4-kb StuI-XhoI DNA fragment of R. pickettii DTP0602 hydroxyquinol 1,2-dioxygenase converted hydroxyquinol into maleylacetate and also degraded 6-chlorohydroxyquinol. The 1.4-kb DNA fragment contained one open reading frame (designated hadC) composed of 948 nucleotides. The molecular mass of 34,591 deduced from the gene product (HadC) was in agreement with the size (35 kDa) of the purified HadC protein determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The amino acid sequence of HadC exhibited high homology to that of the hydroxyquinol 1,2-dioxygenase of 2,4,5-trichlorophenoxyacetic acid-degrading Burkholderia cepacia AC1100 (Daubaras, D. L. et al., Appl. Environ. Microbiol., 61, 1279-1289, 1995). The active enzyme had a molecular mass of 68 kDa, suggesting that it is functional as a homodimer. The enzyme also catalyzed the oxidation of pyrogallol and 3-methylcatechol, possible intermediates in the degradation of 2,4,6-trichlorophenol, in addition to 6-chlorohydroxyquinol and hydroxyquinol. The dioxygenase catalyzed both ortho- and meta-cleavage of 3-methylcatechol. << Less

  J Biosci Bioeng 87:267-272(1999) [PubMed] [EuropePMC]

• Pathway for Biodegradation of p-Nitrophenol in a Moraxella sp.

  Spain J.C., Gibson D.T.

  A Moraxella strain grew on p-nitrophenol with stoichiometric release of nitrite. During induction of the enzymes for growth on p-nitrophenol, traces of hydroquinone accumulated in the medium. In the presence of 2,2'-dipyridyl, p-nitrophenol was converted stoichiometrically to hydroquinone. Particu ... >> More

  A Moraxella strain grew on p-nitrophenol with stoichiometric release of nitrite. During induction of the enzymes for growth on p-nitrophenol, traces of hydroquinone accumulated in the medium. In the presence of 2,2'-dipyridyl, p-nitrophenol was converted stoichiometrically to hydroquinone. Particulate enzymes catalyzed the conversion of p-nitrophenol to hydroquinone in the presence of NADPH and oxygen. Soluble enzymes catalyzed the conversion of hydroquinone to gamma-hydroxymuconic semialdehyde, which was identified by high-performance liquid chromatography (HPLC)-mass spectroscopy. Upon addition of catalytic amounts of NAD, gamma-hydroxymuconic semialdehyde was converted to beta-ketoadipic acid. In the presence of pyruvate and lactic dehydrogenase, substrate amounts of NAD were required and gamma-hydroxymuconic semialdehyde was converted to maleylacetic acid, which was identified by HPLC-mass spectroscopy. Similar results were obtained when the reaction was carried out in the presence of potassium ferricyanide. Extracts prepared from p-nitrophenol-growth cells also contained an enzyme that catalyzed the oxidation of 1,2,4-benzenetriol to maleylacetic acid. The enzyme responsible for the oxidation of 1,2,4-benzenetriol was separated from the enzyme responsible for hydroquinone oxidation by DEAE-cellulose chromatography. The results indicate that the pathway for biodegradation of p-nitrophenol involves the initial removal of the nitro group as nitrite and formation of hydroquinone. 1,4-Benzoquinone, a likely intermediate in the initial reaction, was not detected. Hydroquinone is converted to beta-ketoadipic acid via gamma-hydroxymuconic semialdehyde and maleylacetic acid. << Less

  Appl Environ Microbiol 57:812-819(1991) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Characterization of an intradiol dioxygenase involved in the biodegradation of the chlorophenoxy herbicides 2,4-D and 2,4,5-T.

  Travkin V.M., Jadan A.P., Briganti F., Scozzafava A., Golovleva L.A.

  Hydroxyquinol 1,2-dioxygenase, an intradiol dioxygenase, which catalyzes the cleaving of the aromatic ring of hydroxyquinol, a key intermediate of 2,4-D and 2,4,5-T degradation, was purified from Nocardioides simplex 3E cells grown on 2,4-D as the sole carbon source. This enzyme exhibits a highly ... >> More

  Hydroxyquinol 1,2-dioxygenase, an intradiol dioxygenase, which catalyzes the cleaving of the aromatic ring of hydroxyquinol, a key intermediate of 2,4-D and 2,4,5-T degradation, was purified from Nocardioides simplex 3E cells grown on 2,4-D as the sole carbon source. This enzyme exhibits a highly restricted substrate specificity and is able to cleave hydroxyquinol (K(m) for hydroxyquinol as a substrate was 1.2 microM, V(max) 55 U/mg, K(cat) 57 s-1 and K(cat)/K(m) 47.5 microM s-1), 6-chloro- and 5-chlorohydroxyquinol. Different substituted catechols and hydroquinones are not substrates for this enzyme. This enzyme appears to be a dimer with two identical 37-kDa subunits. Protein and iron analyses indicate an iron stoichiometry of 1 iron/65 kDa homodimer, alpha2 Fe. Both the electronic absorption spectrum which shows a broad absorption band with a maximum at 450 nm and the electron paramagnetic resonance spectra are consistent with a high-spin iron(III) ion in a rhombic environment typical of the active site of intradiol cleaving enzymes. << Less

  FEBS Lett. 407:69-72(1997) [PubMed] [EuropePMC]