2.50
Hdl Handle:
http://hdl.handle.net/10033/555420
Title:
Modified 3-oxoadipate pathway for the biodegradation of methylaromatics in Pseudomonas reinekei MT1.
Authors:
Marín, Macarena; Pérez-Pantoja, Danilo; Donoso, Raul; Wray, Victor; González, Bernardo; Pieper, Dietmar H
Abstract:
Catechols are central intermediates in the metabolism of aromatic compounds. Degradation of 4-methylcatechol via intradiol cleavage usually leads to the formation of 4-methylmuconolactone (4-ML) as a dead-end metabolite. Only a few microorganisms are known to mineralize 4-ML. The mml gene cluster of Pseudomonas reinekei MT1, which encodes enzymes involved in the metabolism of 4-ML, is shown here to encode 10 genes found in a 9.4-kb chromosomal region. Reverse transcription assays revealed that these genes form a single operon, where their expression is controlled by two promoters. Promoter fusion assays identified 4-methyl-3-oxoadipate as an inducer. Mineralization of 4-ML is initiated by the 4-methylmuconolactone methylisomerase encoded by mmlI. This reaction produces 3-ML and is followed by a rearrangement of the double bond catalyzed by the methylmuconolactone isomerase encoded by mmlJ. Deletion of mmlL, encoding a protein of the metallo-beta-lactamase superfamily, resulted in a loss of the capability of the strain MT1 to open the lactone ring, suggesting its function as a 4-methyl-3-oxoadipate enol-lactone hydrolase. Further metabolism can be assumed to occur by analogy with reactions known from the 3-oxoadipate pathway. mmlF and mmlG probably encode a 4-methyl-3-oxoadipyl-coenzyme A (CoA) transferase, and the mmlC gene product functions as a thiolase, transforming 4-methyl-3-oxoadipyl-CoA into methylsuccinyl-CoA and acetyl-CoA, as indicated by the accumulation of 4-methyl-3-oxoadipate in the respective deletion mutant. Accumulation of methylsuccinate by an mmlK deletion mutant indicates that the encoded acetyl-CoA hydrolase/transferase is crucial for channeling methylsuccinate into the central metabolism.
Citation:
Modified 3-oxoadipate pathway for the biodegradation of methylaromatics in Pseudomonas reinekei MT1. 2010, 192 (6):1543-52 J. Bacteriol.
Journal:
Journal of bacteriology
Issue Date:
Mar-2010
URI:
http://hdl.handle.net/10033/555420
DOI:
10.1128/JB.01208-09
PubMed ID:
20061479
Type:
Article
Language:
en
ISSN:
1098-5530
Appears in Collections:
publications of the research group microbial interactions and processes (MINP)

Full metadata record

DC FieldValue Language
dc.contributor.authorMarín, Macarenaen
dc.contributor.authorPérez-Pantoja, Daniloen
dc.contributor.authorDonoso, Raulen
dc.contributor.authorWray, Victoren
dc.contributor.authorGonzález, Bernardoen
dc.contributor.authorPieper, Dietmar Hen
dc.date.accessioned2015-05-21T11:09:09Zen
dc.date.available2015-05-21T11:09:09Zen
dc.date.issued2010-03en
dc.identifier.citationModified 3-oxoadipate pathway for the biodegradation of methylaromatics in Pseudomonas reinekei MT1. 2010, 192 (6):1543-52 J. Bacteriol.en
dc.identifier.issn1098-5530en
dc.identifier.pmid20061479en
dc.identifier.doi10.1128/JB.01208-09en
dc.identifier.urihttp://hdl.handle.net/10033/555420en
dc.description.abstractCatechols are central intermediates in the metabolism of aromatic compounds. Degradation of 4-methylcatechol via intradiol cleavage usually leads to the formation of 4-methylmuconolactone (4-ML) as a dead-end metabolite. Only a few microorganisms are known to mineralize 4-ML. The mml gene cluster of Pseudomonas reinekei MT1, which encodes enzymes involved in the metabolism of 4-ML, is shown here to encode 10 genes found in a 9.4-kb chromosomal region. Reverse transcription assays revealed that these genes form a single operon, where their expression is controlled by two promoters. Promoter fusion assays identified 4-methyl-3-oxoadipate as an inducer. Mineralization of 4-ML is initiated by the 4-methylmuconolactone methylisomerase encoded by mmlI. This reaction produces 3-ML and is followed by a rearrangement of the double bond catalyzed by the methylmuconolactone isomerase encoded by mmlJ. Deletion of mmlL, encoding a protein of the metallo-beta-lactamase superfamily, resulted in a loss of the capability of the strain MT1 to open the lactone ring, suggesting its function as a 4-methyl-3-oxoadipate enol-lactone hydrolase. Further metabolism can be assumed to occur by analogy with reactions known from the 3-oxoadipate pathway. mmlF and mmlG probably encode a 4-methyl-3-oxoadipyl-coenzyme A (CoA) transferase, and the mmlC gene product functions as a thiolase, transforming 4-methyl-3-oxoadipyl-CoA into methylsuccinyl-CoA and acetyl-CoA, as indicated by the accumulation of 4-methyl-3-oxoadipate in the respective deletion mutant. Accumulation of methylsuccinate by an mmlK deletion mutant indicates that the encoded acetyl-CoA hydrolase/transferase is crucial for channeling methylsuccinate into the central metabolism.en
dc.language.isoenen
dc.subject.meshAdipatesen
dc.subject.meshBacterial Proteinsen
dc.subject.meshBiodegradation, Environmentalen
dc.subject.meshCulture Mediaen
dc.subject.meshGene Deletionen
dc.subject.meshGene Expression Regulation, Bacterialen
dc.subject.meshHydrocarbons, Aromaticen
dc.subject.meshIsomerasesen
dc.subject.meshLactonesen
dc.subject.meshMolecular Structureen
dc.subject.meshOpen Reading Framesen
dc.subject.meshPseudomonasen
dc.subject.meshSalicylatesen
dc.titleModified 3-oxoadipate pathway for the biodegradation of methylaromatics in Pseudomonas reinekei MT1.en
dc.typeArticleen
dc.identifier.journalJournal of bacteriologyen
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