New Pathways in the Oxidative Metabolism of Aromatic Compounds by Micro-Organisms

Dagley, S.; Wc, Evans; Dw, Ribbons

doi:10.1038/188560a0

Cited by 251 publications

(129 citation statements)

References 26 publications

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“…1); the compound was colourless in acid and had the anticipated UV spectrum (cf. Dagley et al 1960). We confirmed the identification by allowing HCMS to react with ammonium ion and form 2,4-lutidinate, which was confirmed by co-chromatography (HPLC) and identical UV spectra (k max , 207 and 283 nm; shoulder, 227 nm; k min , 252 nm) (cf.…”

Section: Resultssupporting

confidence: 63%

“…Their structural fold bears no resemblance to the fold shared by class I and class II enzymes (Sugimoto et al 1999). Dagley et al (1968) cited the widespread importance of the extradiol cleavage of PCA and inferred biodiversity in the extradiol cleavage enzymes (Dagley et al 1960). PCA is the point of convergence of pathways for degradation of many aromatic compounds, for example p-toluenesulfonate in Comamonas testosteroni T-2 (Cook et al 1999), of m-chlorobenzoate in C. testosteroni BR60 (Nakatsu and Wyndham 1995), and of lignin in Sphingomonas paucimobilis SYK-6 (Noda et al 1990;Hara et al 2003).…”

Section: Introductionmentioning

confidence: 99%

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Protocatechuate 4,5-dioxygenase from Comamonas testosteroni T-2: biochemical and molecular properties of a new subgroup within class III of extradiol dioxygenases

2005

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Comamonas testosteroni T-2 degraded at least eight aromatic compounds via protocatechuate (PCA), whose extradiol ring cleavage to 2-hydroxy-4-carboxymuconate semialdehyde (HCMS) was catalysed by PCA 4,5-dioxygenase (PmdAB). This inducible, heteromultimeric enzyme was purified. It contained two subunits, a (PmdA) and b (PmdB), and the molecular masses of the denatured proteins were 18 kDa and 31 kDa, respectively. PCA was converted stoichiometrically to HCMS with an apparent K m of 55 lM and at a maximum velocity of 1.5 lkat. Structureactivity-relationship analysis by testing 16 related compounds as substrate for purified PmdAB revealed an absolute requirement for the vicinal diol and for the carboxylate group of PCA. Besides PCA, only 5¢-hydroxy-PCA (gallate) induced oxygen uptake. The Nterminal amino acid sequence of each subunit was identical to the corresponding sequences in C. testosteroni BR6020, which facilitated sequencing of the pmdAB genes in strain T-2. Small differences in the amino acid sequence had significant effects on enzyme stability. Several homologues of pmdAB were found in sequence databases. Residues involved in substrate binding are highly conserved among the homologues. Their sequences grouped within the class III extradiol dioxygenases. Based on our biochemical and genetic analyses, we propose a new branch of the heteromultimeric enzymes within that class.

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Section: Resultssupporting

confidence: 63%

Section: Introductionmentioning

confidence: 99%

Protocatechuate 4,5-dioxygenase from Comamonas testosteroni T-2: biochemical and molecular properties of a new subgroup within class III of extradiol dioxygenases

2005

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“…characteristics of the product suggest that this is 3-methylmuconate. An alternative cleavage of 4-methylcatechol was suggested from the spectral data obtained by Dagley, Evans Ribbons (1960), and this has been amply confirmed by Dagley, Chapman, Gibson & Wood (1964) who found that the 2-hydroxy-5-methylmuconic semialdehyde was the product. When, however, 4-methylcatechol was oxidized by the pseudomonad of Dagley & Pate1 (1957), grown on p-cresol, protocatechate was formed.…”

Section: Introductionmentioning

confidence: 81%

Metabolism of o-Cresol by Pseudomonas aeruginosa strain T1

Ribbons¹

1966

Journal of General Microbiology

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SUMMARYThere is evidence that oxidation of o-cresol by Pseudomonas aeruginosa proceeds through 3-methylcatechol and 2-hydroxy-6 -oxohepta-2,4-dienoic acid. 3-Methylcatechol has been characterized as a metabolite in growing cultures, and is oxidized by cells or cell extracts obtained from cultures grown on o-cresol but not by those grown on glucose. The rates of dissimilation of 2-hydroxy-6-oxohepta-2,4-dienoic acid are in excess of its rates of formation from 3-methylcatechol by extracts of cells. The catechol 2,3-oxygenase is formed in response to a variety of inducers and will cleave the ring of catechol and 4-methylcatechol also. The low specificity of the 2,3-oxygenase and earlier enzymic activities (hydroxylases), to both inducers and substrates, is discussed.

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“…Since the catechol extradiol pathway (Fig. 5) was reported for the first time in the 1960s (3,4,27), it has been found to be one of the most common lower pathways involved in degradation of both naturally occurring and man-made aromatic compounds (1,22,25,32). The ortho-aminophenol intermediates produced during degradation of some nitroaromatic compounds do not have the two adjacent hydroxyl groups on the aromatic ring that were previously thought to be necessary for metabolism through the extradiol ring cleavage pathway.…”

Section: Discussionmentioning

confidence: 99%

“…Fully induced cells of strain HL 4-NT-1 were obtained by incubation of the harvested cells in fresh medium with 4-nitrotoluene as the sole carbon source overnight. Uninduced cells were obtained by substitution of NH 4 Cl for 4-nitrotoluene during growth. Cells were harvested by centrifugation and then broken using a French press as described previously (30).…”

Section: Methodsmentioning

confidence: 99%

Reactions Involved in the Lower Pathway for Degradation of 4-Nitrotoluene by Mycobacterium Strain HL 4-NT-1

He¹,

Spain²

2000

Appl Environ Microbiol

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In spite of the variety of initial reactions, the aerobic biodegradation of aromatic compounds generally yields dihydroxy intermediates for ring cleavage. Recent investigation of the degradation of nitroaromatic compounds revealed that some nitroaromatic compounds are initially converted to 2-aminophenol rather than dihydroxy intermediates by a number of microorganisms. The complete pathway for the metabolism of 2-aminophenol during the degradation of nitrobenzene by Pseudomonas pseudoalcaligenes JS45 has been elucidated previously. The pathway is parallel to the catechol extradiol ring cleavage pathway, except that 2-aminophenol is the ring cleavage substrate. Here we report the elucidation of the pathway of 2-amino-4-methylphenol (6-amino-mcresol) metabolism during the degradation of 4-nitrotoluene by Mycobacterium strain HL 4-NT-1 and the comparison of the substrate specificities of the relevant enzymes in strains JS45 and HL 4-NT-1. The results indicate that the 2-aminophenol ring cleavage pathway in strain JS45 is not unique but is representative of the pathways of metabolism of other o-aminophenolic compounds.Nitroaromatic compounds are important industrial feedstocks due to the versatile chemistry of the nitro group (22). Many nitroaromatic compounds are harmful, and their release into the environment has caused concern. The microbial degradation of nitroaromatic compounds is usually initiated by an enzymatic attack on the nitro group (22). One of the strategies involves partial reduction of the nitro group to a hydroxylamino group. The hydroxylamino intermediates can be transformed to catechols which enter the ring cleavage pathways of aerobic degradation of aromatic compounds, as observed during degradation of 4-nitrobenzoate (6, 33), 3-nitrophenol (19), and 4-nitrotoluene (7, 26). Alternatively, the hydroxylamino intermediates can be rearranged, by an intramolecular transfer of the hydroxyl group (10; L. J. Nadeau, Z. He, and J. C. Spain, unpublished data), to ortho-aminophenols, as observed during biodegradation of nitrobenzene (21, 24), 3-or 4-chloronitrobenzene (2, 16, 24), 3-nitrophenol (28), 2-chloro-5-nitrophenol (29), 4-nitrotoluene (30), and 2,4,6-trinitrotoluene (15) by various microorganisms. The initial steps of each of the degradation pathways have been elucidated; however, the lower pathway has been determined only for the metabolism of 2-aminophenol during the degradation of nitrobenzene by Pseudomonas pseudoalcaligenes JS45 (11,14). The pathway is parallel to the catechol extradiol ring cleavage pathway, except that 2-aminophenol is the ring cleavage substrate.Mycobacterium strain HL 4-NT-1 is able to grow on 4-nitrotoluene as the sole source of nitrogen, carbon, and energy (30). 4-Nitrotoluene is converted to 2-amino-4-methylphenol (6-amino-m-cresol) via 4-hydroxylaminotoluene in reactions catalyzed by a nitroreductase and an aminohydroxymutase. In reactions analogous to those used by strain JS45, extracts from induced cells of strain HL 4-NT-1 catalyzed the conversion of 2-amino-4-meth...

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New Pathways in the Oxidative Metabolism of Aromatic Compounds by Micro-Organisms

Cited by 251 publications

References 26 publications

Protocatechuate 4,5-dioxygenase from Comamonas testosteroni T-2: biochemical and molecular properties of a new subgroup within class III of extradiol dioxygenases

Protocatechuate 4,5-dioxygenase from Comamonas testosteroni T-2: biochemical and molecular properties of a new subgroup within class III of extradiol dioxygenases

Metabolism of o-Cresol by Pseudomonas aeruginosa strain T1

Reactions Involved in the Lower Pathway for Degradation of 4-Nitrotoluene by Mycobacterium Strain HL 4-NT-1

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