Purification and sequence analysis of 4-methyl-5-nitrocatechol oxygenase from Burkholderia sp. strain DNT

Haigler, B E; Suen, W C; Spain, Jim C.

doi:10.1128/jb.178.20.6019-6024.1996

Cited by 44 publications

(39 citation statements)

References 46 publications

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“…The tryptophan 2-monoxygenase gene product itself produces indole acetamide, which can be converted to the auxin indole acetic acid by hydrolysis. Most flavin-containing proteins have a highly conserved motif located at the N terminus of the protein and involved in binding of the ADP moiety of FAD (35)(36)(37). The proposed motif (G-X-G-X-X-G-X-X-X-A) is preceded by three or four hydrophobic residues (38).…”

Section: Discussionmentioning

confidence: 99%

Carbocyclic fatty acids in plants: Biochemical and molecular genetic characterization of cyclopropane fatty acid synthesis of Sterculia foetida

Bao

Katz

Pollard

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

132

100

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Fatty acids containing three-member carbocyclic rings are found in bacteria and plants. Bacteria synthesize cyclopropane fatty acids (CPA-FAs) only by the addition of a methylene group from Sadenosylmethionine to the cis-double bond of monoenoic phospholipid-bound fatty acids. In plants CPA-FAs are usually minor components with cyclopropene fatty acids (CPE-FAs) more abundant. Sterculia foetida seed oil contains 65-78% CPE-FAs, principally sterculic acid. To address carbocyclic fatty acid synthesis in plants, a cDNA library was constructed from developing seeds during the period of maximum oil deposition. About 0.4% of 5,300 expressed sequence tags were derived from one gene, which shared similarities to the bacterial CPA-FA synthase. However, the predicted protein is twice as large as the bacterial homolog and represents a fusion of an FAD-containing oxidase at the N terminus and a methyltransferase at the C terminus. Functional analysis of the isolated full-length cDNA was conducted in tobacco suspension cells where its expression resulted in the accumulation of up to 6.2% dihydrosterculate of total fatty acids. In addition, the dihydrosterculate was specifically labeled by [methyl-14 C]methionine and by [ 14 C]oleic acid in the transgenic tobacco cells. In in vitro assay of S. foetida seed extracts, S-adenosylmethionine served as a methylene donor for the synthesis of dihydrosterculate from oleate. Dihydrosterculate accumulated largely in phosphatidylcholine in both systems. Together, a CPA-FA synthase was identified from S. foetida, and the pathway in higher plants that produce carbocyclic fatty acids was defined as by transfer of C 1 units, most likely from S-adenosylmethionine to oleate.

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Section: Discussionmentioning

confidence: 99%

Carbocyclic fatty acids in plants: Biochemical and molecular genetic characterization of cyclopropane fatty acid synthesis of Sterculia foetida

Bao

Katz

Pollard

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

132

100

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“…Previous work demonstrated that the highly specific 4M5NC monooxygenase from the 2,4-DNT pathway does not attack 3M4NC (9). The 3M4NC-2,3-dioxygenase from the 2,6-DNT pathway also appears to be highly specific for 3M4NC, with the only other substantial activity being against 3-methylcatechol.…”

Section: Revealed a Base Peak At M/z 158 And As Further Demonstratedmentioning

confidence: 99%

Aerobic Degradation of Dinitrotoluenes and Pathway for Bacterial Degradation of 2,6-Dinitrotoluene

Nishino¹,

Paoli²,

Spain³

2000

Appl Environ Microbiol

167

143

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An oxidative pathway for the mineralization of 2,4-dinitrotoluene (2,4-DNT) by Burkholderia sp. strain DNT has been reported previously. We report here the isolation of additional strains with the ability to mineralize 2,4-DNT by the same pathway and the isolation and characterization of bacterial strains that mineralize 2,6-dinitrotoluene (2,6-DNT) by a different pathway. Burkholderia cepacia strain JS850 and Hydrogenophaga palleronii strain JS863 grew on 2,6-DNT as the sole source of carbon and nitrogen. The initial steps in the pathway for degradation of 2,6-DNT were determined by simultaneous induction, enzyme assays, and identification of metabolites through mass spectroscopy and nuclear magnetic resonance. 2,6-DNT was converted to 3-methyl-4-nitrocatechol by a dioxygenation reaction accompanied by the release of nitrite. 3-Methyl-4-nitrocatechol was the substrate for extradiol ring cleavage yielding 2-hydroxy-5-nitro-6-oxohepta-2,4-dienoic acid, which was converted to 2-hydroxy-5-nitropenta-2,4-dienoic acid. 2,4-DNT-degrading strains also converted 2,6-DNT to 3-methyl-4-nitrocatechol but did not metabolize the 3-methyl-4-nitrocatechol. Although 2,6-DNT prevented the degradation of 2,4-DNT by 2,4-DNT-degrading strains, the effect was not the result of inhibition of 2,4-DNT dioxygenase by 2,6-DNT or of 4-methyl-5-nitrocatechol monooxygenase by 3-methyl-4-nitrocatechol.2,6-Dinitrotoluene (2,6-DNT) and 2,4-dinitrotoluene (2,4-DNT) occur as soil and groundwater contaminants at former 2,4,6-trinitrotoluene (TNT) production sites and in the wastewater from the commercial production of feedstocks for polyurethane foam (23). Twenty years after the cessation of TNT production in the United States, the manufacturing sites are still heavily contaminated with both 2,4-and 2,6-DNT even though 2,4-DNT-mineralizing bacteria can be readily isolated from the contaminated material (26). Commercial manufacture of DNT results in the release of DNT to industrial and municipal waste treatment systems (information found at the Environmental Health Center website [http://safety.webfirst .com/ehc/ew/chemical.htm] and in the TOXNET Toxics Release Inventory [http://six.nlm.nih.gov/sis1]). The unpredictable presence of DNT in the waste streams sent to the treatment plants can cause upsets in the ability of activated sludges to effectively remove the organic components in the waste streams (11). 2,4-and 2,6-DNT are priority pollutants (13), and industrial waste streams from DNT-manufacturing facilities are specifically regulated by the U.S. Environmental Protection Agency (40 CFR 261.32).Contaminated munitions manufacturing sites are ready sources of bacteria able to mineralize 2,4-DNT, but bacteria able to grow on 2,6-DNT have been more elusive. The bacterial pathway for degradation of 2,4-DNT (8, 28) is initiated by dioxygenation of 2,4-DNT, which results in the formation of 4-methyl-5-nitrocatechol (4M5NC) and the release of nitrite; monooxygenation of 4M5NC then yields 2-hydroxy-5-methylquinone, which is subsequently reduced to 2,4...

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“…In Burkholderia sp. strain DNT (58,59,61,184,186,187) and Burkholderia cepacia R34 (85,86,131), the 4-methyl-5-nitrocatechol produced from 2,4-dinitrotoluene is oxidized by a monooxygenase to remove the second nitro group, forming 2,4,5-trihydroxytoluene, which is a substrate for meta ring cleavage (85). In contrast, metabolism of 2,6-dinitrotoluene by B. cepacia JS850 and Hydrogenophaga palleronii JS863 yields 3-methyl-4-nitrocatechol (Fig.…”

Section: Pathways For Nitrotoluene Catabolismmentioning

confidence: 99%

Nitroaromatic Compounds, from Synthesis to Biodegradation

Parales

2010

Microbiol Mol Biol Rev

772

470

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SUMMARY Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed.

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Purification and sequence analysis of 4-methyl-5-nitrocatechol oxygenase from Burkholderia sp. strain DNT

Cited by 44 publications

References 46 publications

Carbocyclic fatty acids in plants: Biochemical and molecular genetic characterization of cyclopropane fatty acid synthesis of Sterculia foetida

Carbocyclic fatty acids in plants: Biochemical and molecular genetic characterization of cyclopropane fatty acid synthesis of Sterculia foetida

Aerobic Degradation of Dinitrotoluenes and Pathway for Bacterial Degradation of 2,6-Dinitrotoluene

Nitroaromatic Compounds, from Synthesis to Biodegradation

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