Publications

• Cloning and sequencing of a novel meta-cleavage dioxygenase gene whose product is involved in degradation of gamma-hexachlorocyclohexane in Sphingomonas paucimobilis.

  Miyauchi K., Adachi Y., Nagata Y., Takagi M.

  Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole source of carbon and energy. In a previous study, we showed that gamma-HCH is degraded to chlorohydroquinone (CHQ) and then to hydroquinone (HQ), alt ... >> More

  Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole source of carbon and energy. In a previous study, we showed that gamma-HCH is degraded to chlorohydroquinone (CHQ) and then to hydroquinone (HQ), although the rate of reaction from CHQ to HQ was slow (K. Miyauchi, S. K. Suh, Y. Nagata, and M. Takagi, J. Bacteriol. 180:1354-1359, 1998). In this study, we cloned and characterized a gene, designated linE, which is located upstream of linD and is directly involved in the degradation of CHQ. The LinE protein consists of 321 amino acids, and all of the amino acids which are reported to be essential for the activity of meta-cleavage dioxygenases are conserved in LinE. Escherichia coli overproducing LinE could convert both CHQ and HQ, producing gamma-hydroxymuconic semialdehyde and maleylacetate, respectively, with consumption of O(2) but could not convert catechol, which is one of the major substrates for meta-cleavage dioxygenases. LinE seems to be resistant to the acylchloride, which is the ring cleavage product of CHQ and which seems to react with water to be converted to maleylacetate. These results indicated that LinE is a novel type of meta-cleavage dioxygenase, designated (chloro)hydroquinone 1, 2-dioxygenase, which cleaves aromatic rings with two hydroxyl groups at para positions preferably. This study represents a direct demonstration of a new type of ring cleavage pathway for aromatic compounds, the hydroquinone pathway. << Less

  J. Bacteriol. 181:6712-6719(1999) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Cloning and sequencing of a 2,5-dichlorohydroquinone reductive dehalogenase gene whose product is involved in degradation of gamma-hexachlorocyclohexane by Sphingomonas paucimobilis.

  Miyauchi K., Suh S.-K., Nagata Y., Takagi M.

  Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole carbon and energy source. In a previous study, we showed that gamma-HCH is degraded to 2,5-dichlorohydroquinone (2,5-DCHQ) (Y. Nagata, R. Ohtomo, K. ... >> More

  Sphingomonas (formerly Pseudomonas) paucimobilis UT26 utilizes gamma-hexachlorocyclohexane (gamma-HCH), a halogenated organic insecticide, as a sole carbon and energy source. In a previous study, we showed that gamma-HCH is degraded to 2,5-dichlorohydroquinone (2,5-DCHQ) (Y. Nagata, R. Ohtomo, K. Miyauchi, M. Fukuda, K. Yano, and M. Takagi, J. Bacteriol. 176:3117-3125, 1994). In the present study, we cloned and characterized a gene, designated linD, directly involved in the degradation of 2,5-DCHQ. The linD gene encodes a peptide of 343 amino acids and has a low level of similarity to proteins which belong to the glutathione S-transferase family. When LinD was overproduced in Escherichia coli, a 40-kDa protein was found after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Northern blot analysis revealed that expression of the linD gene was induced by 2,5-DCHQ in S. paucimobilis UT26. Thin-layer chromatography and gas chromatography-mass spectrometry analyses with the LinD-overexpressing E. coli cells revealed that LinD converts 2,5-DCHQ rapidly to chlorohydroquinone (CHQ) and also converts CHQ slowly to hydroquinone. LinD activity in crude cell extracts was increased 3.7-fold by the addition of glutathione. All three of the Tn5-induced mutants of UT26, which lack 2,5-DCHQ dehalogenase activity, had rearrangements or a deletion in the linD region. These results indicate that LinD is a glutathione-dependent reductive dehalogenase involved in the degradation of gamma-HCH by S. paucimobilis UT26. << Less

  J. Bacteriol. 180:1354-1359(1998) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Cloning and characterization of a gene cluster involved in the catabolism of p-nitrophenol from Pseudomonas putida DLL-E4.

  Shen W., Liu W., Zhang J., Tao J., Deng H., Cao H., Cui Z.

  A 9.2-kb DNA fragment encoding the enzymes of a p-nitrophenol (PNP) catabolic pathway from Pseudomonas putida DLL-E4 was cloned and sequenced. Ten open reading frames (ORFs) were found and five ORFs were functionally verified. The pnpA and pnpC gene products were purified to homogeneity by Ni-NTA ... >> More

  A 9.2-kb DNA fragment encoding the enzymes of a p-nitrophenol (PNP) catabolic pathway from Pseudomonas putida DLL-E4 was cloned and sequenced. Ten open reading frames (ORFs) were found and five ORFs were functionally verified. The pnpA and pnpC gene products were purified to homogeneity by Ni-NTA chromatography. PnpA is a flavin adenine dinucleotide-dependent single-component PNP 4-monooxygenase which converts p-nitrophenol to para-benzoquinone in the presence of NADH and FAD. PnpC is a 1,2,4-trihydroxybenzene (BT) 1,2-dioxygenase which converts BT to maleylacetate. The hydroquinone (HQ) dioxygenase (PnpC1C2) multi-component protein complex was expressed in Escherichia coli via plasmid pET-pnpC1C2 containing pnpC1 and pnpC2. This complex converts HQ to gamma-hydroxymuconic semialdehyde. pnpR is a lysR-type regulator gene. PnpR is a positive regulator involved in HQ degradation in pnp gene cluster. These results demonstrate that a pathway encoded by the pnp gene cluster is involved in degradation of HQ and BT in P. putida DLL-E4. << Less

  Bioresour Technol 101:7516-7522(2010) [PubMed] [EuropePMC]

• Hydroquinone dioxygenase from pseudomonas fluorescens ACB: a novel member of the family of nonheme-iron(II)-dependent dioxygenases.

  Moonen M.J., Synowsky S.A., van den Berg W.A., Westphal A.H., Heck A.J., van den Heuvel R.H., Fraaije M.W., van Berkel W.J.

  Hydroquinone 1,2-dioxygenase (HQDO), an enzyme involved in the catabolism of 4-hydroxyacetophenone in Pseudomonas fluorescens ACB, was purified to apparent homogeneity. Ligandation with 4-hydroxybenzoate prevented the enzyme from irreversible inactivation. HQDO was activated by iron(II) ions and c ... >> More

  Hydroquinone 1,2-dioxygenase (HQDO), an enzyme involved in the catabolism of 4-hydroxyacetophenone in Pseudomonas fluorescens ACB, was purified to apparent homogeneity. Ligandation with 4-hydroxybenzoate prevented the enzyme from irreversible inactivation. HQDO was activated by iron(II) ions and catalyzed the ring fission of a wide range of hydroquinones to the corresponding 4-hydroxymuconic semialdehydes. HQDO was inactivated by 2,2'-dipyridyl, o-phenanthroline, and hydrogen peroxide and inhibited by phenolic compounds. The inhibition with 4-hydroxybenzoate (K(i) = 14 microM) was competitive with hydroquinone. Online size-exclusion chromatography-mass spectrometry revealed that HQDO is an alpha2beta2 heterotetramer of 112.4 kDa, which is composed of an alpha-subunit of 17.8 kDa and a beta-subunit of 38.3 kDa. Each beta-subunit binds one molecule of 4-hydroxybenzoate and one iron(II) ion. N-terminal sequencing and peptide mapping and sequencing based on matrix-assisted laser desorption ionization--two-stage time of flight analysis established that the HQDO subunits are encoded by neighboring open reading frames (hapC and hapD) of a gene cluster, implicated to be involved in 4-hydroxyacetophenone degradation. HQDO is a novel member of the family of nonheme-iron(II)-dependent dioxygenases. The enzyme shows insignificant sequence identity with known dioxygenases. << Less

  J Bacteriol 190:5199-5209(2008) [PubMed] [EuropePMC]