hydroxymuconic-semialdehyde has been researched along with hydroquinone* in 3 studies
3 other study(ies) available for hydroxymuconic-semialdehyde and hydroquinone
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An unexpected gene cluster for downstream degradation of alkylphenols in Sphingomonas sp. strain TTNP3.
In silico analysis of nucleotide sequences flanking the recently found hydroquinone dioxygenase in Sphingomonas sp. strain TTNP3 revealed a gene cluster that encodes a hydroquinone catabolic pathway. In addition to the two open-reading frames encoding the recently characterized hydroquinone dioxygenase, the cluster consisted of six open-reading frames. We were able to express the three open-reading frames, hqdC, hqdD, and hqdE, and demonstrated that the three gene products, HqdC, HqdD, and HqdE had 4-hydroxymuconic semialdehyde dehydrogenase, maleylacetate reductase, and intradiol dioxygenase activity, respectively. Surprisingly, the gene cluster showed similarities to functionally related clusters found in members of the β- and γ-proteobacteria rather than to those found in other members of the genus Sphingomonas sensu latu. Topics: Bacterial Proteins; Biodegradation, Environmental; Biotechnology; Dioxygenases; Fatty Acids, Unsaturated; Genes, Bacterial; Hydroquinones; Molecular Sequence Data; Multigene Family; Oxidoreductases; Oxidoreductases Acting on CH-CH Group Donors; Phenols; Sequence Analysis, DNA; Sphingomonas | 2012 |
Hydroquinone dioxygenase from pseudomonas fluorescens ACB: a novel member of the family of nonheme-iron(II)-dependent dioxygenases.
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. Topics: 2,2'-Dipyridyl; Acetophenones; Amino Acid Sequence; Chromatography, Gel; DNA, Bacterial; Enzyme Activators; Enzyme Inhibitors; Enzyme Stability; Fatty Acids, Unsaturated; Hydrogen Peroxide; Hydroquinones; Iron; Mass Spectrometry; Molecular Sequence Data; Molecular Weight; Multigene Family; Open Reading Frames; Oxygenases; Parabens; Phenanthrolines; Protein Subunits; Pseudomonas fluorescens; Sequence Homology, Amino Acid; Substrate Specificity; Temperature | 2008 |
Elucidation of the 4-hydroxyacetophenone catabolic pathway in Pseudomonas fluorescens ACB.
The catabolism of 4-hydroxyacetophenone in Pseudomonas fluorescens ACB is known to proceed through the intermediate formation of hydroquinone. Here, we provide evidence that hydroquinone is further degraded through 4-hydroxymuconic semialdehyde and maleylacetate to beta-ketoadipate. The P. fluorescens ACB genes involved in 4-hydroxyacetophenone utilization were cloned and characterized. Sequence analysis of a 15-kb DNA fragment showed the presence of 14 open reading frames containing a gene cluster (hapCDEFGHIBA) of which at least four encoded enzymes are involved in 4-hydroxyacetophenone degradation: 4-hydroxyacetophenone monooxygenase (hapA), 4-hydroxyphenyl acetate hydrolase (hapB), 4-hydroxymuconic semialdehyde dehydrogenase (hapE), and maleylacetate reductase (hapF). In between hapF and hapB, three genes encoding a putative intradiol dioxygenase (hapG), a protein of the Yci1 family (hapH), and a [2Fe-2S] ferredoxin (hapI) were found. Downstream of the hap genes, five open reading frames are situated encoding three putative regulatory proteins (orf10, orf12, and orf13) and two proteins possibly involved in a membrane efflux pump (orf11 and orf14). Upstream of hapE, two genes (hapC and hapD) were present that showed weak similarity with several iron(II)-dependent extradiol dioxygenases. Based on these findings and additional biochemical evidence, it is proposed that the hapC and hapD gene products are involved in the ring cleavage of hydroquinone. Topics: Acetophenones; Adipates; Bacterial Proteins; Cloning, Molecular; DNA, Bacterial; Enzymes; Fatty Acids, Unsaturated; Ferredoxins; Hydroquinones; Magnetic Resonance Spectroscopy; Maleates; Membrane Transport Proteins; Metabolic Networks and Pathways; Molecular Sequence Data; Multigene Family; Open Reading Frames; Oxidoreductases Acting on CH-CH Group Donors; Oxygenases; Pseudomonas fluorescens; Sequence Analysis, DNA | 2008 |