PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Catechol 2,3-Dioxygenase”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1992

Molecular cloning and characterization of catechol 2,3-dioxygenases from biphenyl/polychlorinated biphenyls-degrading bacteria.

Catechol 2,3-dioxygenases were cloned from Alcaligenes sp. KF711, Pseudomonas putida KF715, and Achromobacter xylosoxidans KF701 which are biphenyl/polychlorinated biphenyls-degrading bacteria. All of the cloned enzymes were purified by preparative polyacrylamide gel electrophoresis (PAGE). The purified catechol 2,3-dioxygenases were significantly different from one another in ring-fission activities to catechol and its derivatives. The catechol 2,3-dioxygenase from Alcaligenes sp. KF711 exhibited higher ring-fission activity to 4-chlorocatechol than those from P. putida KF715 and A. xylosoxidans KF701. In electrophoretic mobilities, the three enzymes were different from one another on nondenaturing PAGE but the same on SDS-PAGE.

Alcaligenes↗
PubMed1990

Immobilized and free cell continuous cultures of a recombinant E. coli producing catechol 2,3-dioxygenase in a two-stage chemostat: improvement of plasmid stability.

The immobilization of recombinant strains of E. coli W3110/pTG205 in K-carrageenan gel beads improves the plasmid stability during continuous cultures in the absence of selection pressure. Since, xyl E gene (which encodes catechol 2,3-dioxygenase from Pseudomonas putida) transcription is controlled by the trp promoter, the effects of tryptophan (repressor) and 3 beta-indolyl acrylic acid (derepressor) on pTG 205 stability and enzyme production have been studied in both free and immobilized cell cultures. A two-stage continuous culture system running for 150 h is described. In the first stage an immobilized culture is performed in the presence of tryptophan with a significant plasmid stability. The cells released from the gel beads are continuously transferred in the second stage reactor where expression is induced by 3 beta-indolyl acrylic acid. In these conditions an efficient production of catechol 2,3-dioxygenase is observed.

Biotechnology↗
PubMed1992

[Expression and distribution of catechol 2,3-dioxygenase in Escherichia coli].

A series of new plasmids containing xylE gene was constructed based on the shuttle plasmid pTG 402 between E. coli and B. subtilis. The expressed xylE gene product catechol 2,3-dioxygenase (CatO2ase) was measured for its output and distribution, and analysed for its structural hydrophobicity and hydrophilicity. It was demonstrated that the output of CatO2ase was relative to plasmids, host cells, culture time and with or without induction. The enzyme didn't have features of excretional proteins and was mostly distributed inside the cells though a little could be detected in culture medium. It can be used as a selective marker, indicator and monitor in the study of genetic engineering. This research also provides a scientific basis for eliminating pollution of aromatic hydrocabonic compounds with genetic engineering bacteria.

Base Sequence↗
PubMed1992

Molecular cloning and mapping of phenol degradation genes from Bacillus stearothermophilus FDTP-3 and their expression in Escherichia coli.

Two genes of the meta pathway of phenol degradation were cloned from a phenol-utilizing strain of Bacillus stearothermophilus and were mapped by subcloning and by use of a Tn5 insertion mutation. They code for phenol hydroxylase and catechol 2,3-dioxygenase, respectively. The gene encoding catechol 2,3-dioxygenase, which is more thermostable than catechol 2,3-dioxygenase encoded by the other gene, shares rather limited homology with that from Pseudomonas putida.

Catechol 2,3-Dioxygenase↗
PubMed1992

Degradation of phenol and phenolic compounds by Pseudomonas putida EKII.

The phenol-degrading strain Pseudomonas putida EKII was isolated from a soil enrichment culture and utilized phenol up to 10.6 mM (1.0 g.l-1) as the sole source of carbon and energy. Furthermore, cresols, chlorophenols, 3,4-dimethylphenol, and 4-chloro-m-cresol were metabolized as sole substrates by phenol-grown resting cells of strain EKII. Under conditions of cell growth, degradation of these xenobiotics was achieved only in co-metabolism with phenol. Phenol hydroxylase activity was detectable in whole cells but not in cell-free extracts. The specificity of the hydroxylating enzyme was found during transformation of cresols and chlorophenols: ortho- and meta-substituted phenols were degraded via 3-substituted catechols, while degradation of para-substituted phenols proceeded via 4-substituted catechols. In cell-free extracts of phenol-grown cells a high level of catechol 2,3-dioxygenase as well as smaller amounts of 2-hydroxymuconic semialdehyde hydrolyase and catechol 1,2-dioxygenase were detected. The ring-cleaving enzymes were characterized after partial purification by DEAE-cellulose chromatography.

Biodegradation, Environmental↗
PubMed1977

Isolation of mutants with altered metabolic control of the NAH plasmid-encoded catechol meta-cleavage pathway.

Two types of mutants which displayed altered regulation of the NAH catabolic plasmid-encoded catechol meta-cleavage pathway were isolated in Pseudomonas putida. Altered metabolic control was indicated by assay of catechol 2,3-dioxygenase. In one type of mutant the catechol 2,3-dioxygenase was synthesized constitutively. In the other type the range of carbon sources which induce the catechol 2,3-dioxygenase was increased.

Catechols↗
PubMed1992

Plasmid instabilities of single and three-plasmid systems in Escherichia coli during continuous cultivation.

Plasmid instabilities in E. coli JM103 carrying three plasmids (pRK248cI, pMTC48, pEcoR4) and a single plasmid system (pTG206) for the production of fusion EcoRI (SPA::EcoRI) and catechol 2,3-dioxygenase, respectively, were investigated in continuous cultures under selective and non-selective conditions. In a three-plasmid system, pRK248cI was lost gradually together with pMTC48 from the host under non-selective conditions. The selective pressure against pRK248cI stabilized the pMTC48. This indicates that the loss of pMTC48 under non-selective conditions was caused by the loss of cI857 gene (coded by pRK248cI) which resulted in the overproduction of the toxic gene product (coded by pMTC48). In the case of single plasmid (pTG206) system, the plasmid lost from the host under non-selective conditions. This plasmid was stabilized in the host growing under selective conditions. During this period we obtained some ampicillin resistant colonies which gave low levels of enzyme activities compared to the normal plasmid bearing cells. Plasmid analysis from the above cells showed that the plasmid has undergone structural instability. Further, restriction analysis of this plasmid exhibited an additional PvuII site in a 0.9 kbp fragment that was integrated near the tet promoter which controls the expression of the xyl E gene, thereby resulting low levels of enzyme activities. Our results indicate that some of the IS elements which are present in the host chromosome were responsible for such instabilities to turn off the synthesis by inserting into the tet promoter region to lower the protein formation during the bioprocess.

Base Sequence↗
PubMed1992

Degradation of 2-methylbenzoic acid by Pseudomonas cepacia MB2.

We report the isolation of Pseudomonas cepacia MB2, believed to be the first microorganism to utilize 2-methylbenzoic acid as the sole carbon source. Its growth range included all mono- and dimethylbenzoates (with the exception of 2,5- and 2,6-dimethylbenzoates) and 3-chloro-2-methylbenzoate (but not 4- or 5-chloro-2-methylbenzoate) but not chlorobenzoates lacking a methyl group. 2-Chlorobenzoate, 3-chlorobenzoate, and 2,3-, 2,4-, and 3,4-dichlorobenzoates inhibited growth of MB2 on 2-methylbenzoate as a result of cometabolism to the corresponding chlorinated catechols which blocked the key enzyme catechol 2,3-dioxygenase. A metapyrocatechase-negative mutant, MB2-G5, showed accumulation of dimethylcatechols from 2,3- and 3,4-dimethylbenzoates, and phenols were detected in resting-cell transformation extracts bearing the same substitution pattern as the original substrate, presumably following thermal degradation of the intermediate dihydrodiol. 2-Methylphenol was also found in extracts of the mutant cells with 2-methylbenzoate. These observations suggested a major route of methylbenzoate metabolism to be dioxygenation to a carboxy-hydrodiol which then forms a catechol derivative. In addition, the methyl group of 2-methylbenzoate was oxidized to isobenzofuranone (by cells of MB2-G5) and to phthalate (by cells of a separate mutant that could not utilize phthalate, MB2-D2). This pathway also generated a chlorinated isobenzofuranone from 3-chloro-2-methylbenzoate.

Benzoates↗
PubMed1990

Molecular cloning of the xylL-xylE region from the P. putida TOL plasmid, pDK1.

A 5.2 kilobase EcoRI restriction fragment from the Pseudomonas putida HS1 TOL plasmid pDK1, encoding a portion of the lower toluene degradation pathway, was cloned into the E. coli plasmid pBR325. A detailed map of the restriction endonuclease sites was constructed and the nucleotide sequence of three contiguous XhoI fragments, with a combined total length of approximately 3.9 kilobases, has been investigated. This region was determined to contain a total of four separate open reading frames, each preceded by an identical putative ribosome-binding site (nucleotide sequence of 5'-GAGGTG-3'). These open reading frames have been tentatively identified as encoding the lower pathway enzymes catechol 2,3-dioxygenase (C23O) and 1,2-dihydroxycyclohexa-3,5-diene carboxylate dehydrogenase (DHCDH) and a subunit of the toluate 1,2-dioxygenase complex (TO).

Catechol 2,3-Dioxygenase↗
PubMed1990

Initial steps in the degradation of benzene sulfonic acid, 4-toluene sulfonic acids, and orthanilic acid in Alcaligenes sp. strain O-1.

Alcaligenes sp. strain O-1 grew with benzene sulfonate (BS) as sole carbon source for growth with either NH4+ or NH4+ plus orthanilate (2-aminobenzene sulfonate, OS) as the source(s) of nitrogen. The intracellular desulfonative enzyme did not degrade 3- or 4-aminobenzene sulfonates in the medium, although the enzyme in cell extracts degraded these compounds. We deduce the presence of a selective permeability barrier to sulfonates and conclude that the first step in sulfonate metabolism is transport into the cell. Cell-free desulfonation of BS in standard reaction mixtures required 2 mol of O2 per mol. One mol of O2 was required for a catechol 2,3-dioxygenase. When meta ring cleavage was inhibited with 3-chlorocatechol in desalted extracts, about 1 mol each of O2 and of NAD(P)H per mol of BS were required for the reaction, and SO3(2-) and catechol were recovered in high yield. Catechol was shown to be formed by dioxygenation in an experiment involving 18O2. 4-Toluene sulfonate was subject to NAD(P)H-dependent dioxygenation to yield SO3(2-) and 4-methylcatechol, which was subject to meta cleavage. OS also required 2 mol of O2 per mol and NAD(P)H for degradation, and SO3(2-) and NH4+ were recovered quantitatively. Inhibition of ring cleavage with 3-chlorocatechol reduced the oxygen requirement to 1 mol per mol of OS SO3(2-) (1 mol) and an unidentified organic intermediate, but no NH4+, were observed.

Alcaligenes↗
PubMed1977

A comparative study of the NAH and TOL catabolic plasmids in Pseudomonas putida.

A comparative study of the NAH and TOL catabolic plasmids was carried out to provide information for future genetic manipulation experiments involving these two plasmids. The plasmids were studied in a strain of P. putida and its mutant derivatives. The NAH and TOL plasmids were found to be incompatible. Under the conditions used in these experiments the TOL plasmid transferred into some strains into which NAH was unable to transfer. The use of mutants to remove certain catabolic activities encoded by the bacterial host cell facilitated the allocation of growth genotypes to the NAH and TOL plasmids. TOL encoded the degradation of benzoate, m-toluate and p-toluate, whereas NAH encoded the degradation of naphthalene and salicylate. The other plasmid-associated growth phenotypes were partly plasmid-specified and partly specified by the host cell. The pH optimum of the catechol 2,3-dioxygenase specified by the TOL plasmid was approximately 6.7, whereas that of the NAH-encoded enzyme was approximately 8.3.

Naphthalenes↗
PubMed1992

Utilization of 3-chloro-2-methylbenzoic acid by Pseudomonas cepacia MB2 through the meta fission pathway.

Pseudomonas cepacia MB2 grew on 3-chloro-2-methylbenzoate as a sole carbon source by metabolism through the meta fission pathway with the subsequent liberation of chloride. meta pyrocatechase activity in cell extracts was induced strongly by 3-chloro-2-methylbenzoate, but not by nongrowth analogs 4- or 5-chloro-2-methylbenzoate. Although rapid turnover of metabolites precluded direct identification, a mutant strain MB2-G5 lacking meta pyrocatechase activity produced 4-chloro-3-methylcatechol when incubated with 3-chloro-2-methylbenzoate. The catecholic product, confirmed by nuclear magnetic resonance and mass spectral analyses, produced a transient meta fission product (lambda max = 391 nm) from cell extracts of the wild-type MB2 strain. Further confirmation of meta pyrocatechase activity was noted by conversion of 4-chlorocatechol to 2-hydroxy-5-chloromuconic semialdehyde, which was not further metabolized. In contrast to 3-chlorocatechol, which was not metabolized and is known to generate suicidal products, 4-chlorocatechols do not generate acyl halides. Thus, further metabolism of the ring fission products is governed in strain MB2 by their suitability as substrates for the hydrolase.

Burkholderia cepacia↗
PubMed1977

Comparison of two dioxygenases from Pseudomonas putida.

Catechol 2,3-dioxygenase and homoprotocatechuate 2,3-dioxygenase were purified from the same strain of Pseudomonas putida. Molecular weights and subunit sizes were similar, but amino acid compositions showed some marked differences.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1979

[Degradation and biosynthesis of L-phenylalanine by chloridazon-degrading bacteria].

Incubating chloridazon-degrading bacteria with L-phenylalanine leads to the accumulation of L-2,3-dihydroxyphenylalanine, o-tyrosine and m-tyrosine in the medium. Incubating the bacteria with N-acetyl-L-phenylalanine leads to N-acetyl-(2,3-dihydroxyphenyl)alanine. Using phenylacetic acid as substrate leads to the accumulation of malonic acid. The products are isolated by gel chromatography and high performance liquid chromatography. 2,3-Dihydroxy-L-phenylalanine is attacked by a catechol 2,3-dioxygenase in the presence of Fe2. An unstable yellow compound is formed in this reaction. This meta-cleavage-product is again cleaved by a hydrolase, leading to aspartic acid and 4-hydroxy-2-oxovaleric acid. Both products were isolated fromthe reaction buffer by amino acid analysis and high performance liquid chromatography. The dioxygenase and hydrolase were partially purified and characterized. A new degradation pathway for phenylalanine is discussed and compared with known pathways. The enzymes chorismate mutase, prephenate dehydratase and prephenate dehydrogenase are characterized and inhibition as well as repression are investigated. Only prephenate dehydrogenase is inhibited by phenylalanine, tyrosine and tryptophane. Chorismate mutase is repressed by phenylalanine, prephenate dehydrogenase by phenylalanine and tyrosine. Prephenate dehydratase is not repressed by aromatic amino acids. Regulation of aromatic amino acid biosynthesis in connection with phenylalanine degradation is discussed.

Bacteria↗
PubMed1990

Agitation rate effects on plasmid stability in immobilized and free-cell continuous cultures of recombinant E. coli.

Escherichia coli B/pTG201 recombinant cells were immobilized by entrapment in a carrageenan gel and cultivated in nonselective media to investigate the effect of agitation rate on plasmid stability, biomass concentration, and enzyme productivity. These parameters were studied in continuous cultures for free and immobilized cells, respectively. Immobilized recombinant cells exhibit an increase in the stability of the plasmid pTG201 compared to free cells, even under conditions where the tendency of plasmid stability for free cells decreased generally more rapidly under a higher agitation rate. Intensive agitation, resulting also in a strong shear stress, greatly reduced cell concentration within gel beads throughout the course of growth. Higher enzyme expression of catechol 2-3, dioxygenase was also obtained in leaked cells due to better maintenance of plasmid stability and higher plasmid copy number with regard to free cells. Enzyme productivity of leaked and free cells in minimal medium decreased with the increase in agitation rate, due to decreased plasmid stability; however, in LB medium, it increased in the presence of higher agitation rate related to important cell concentration.

Catechol 2,3-Dioxygenase↗
PubMed1990

Hyperproduction of a bifunctional hybrid protein, metapyrocatechase-protein A, by gene fusion.

A hybrid protein between metapyrocatechase and Staphylococcal protein A was produced by recombinant DNA techniques. A plasmid carrying the fusion gene that encodes the hybrid protein was constructed and expressed in E. coli. Over 70% of soluble proteins of the cell extracts was estimated to be the hybrid protein. This fusion protein is about 65,000. Both the IgG-binding activity of protein A and the metapyrocatechase activity were found in the hybrid protein. The optimum pH of metapyrocatechase in the fusion protein was at around 6.5 and Km was 1.3 X 10(-5) M. A simple immuno-enzymometric assay was developed for anti-BSA antibody using the fusion protein.

Amino Acid Sequence↗
PubMed1991

Phage vectors that allow monitoring of transcription of secondary metabolism genes in Streptomyces.

We describe a bacteriophage phi C31-based system that permits the transcriptional fusion of the convenient reporter gene xylE to chromosomally located promoters in Streptomyces hosts. Applicability of the system to genes for secondary metabolism is demonstrated in an experiment showing that transcription of genes for actinorhodin production in Streptomyces coelicolor A3(2) depends on a transfer RNA gene (bldA) for the rare UUA codon. Two other phi C31::xylE vectors are described that allow detection of promoter activity away from their natural location, either at single copy in a prophage or during lytic infections in plaques.

Anthraquinones↗