Degradation of chloroaromatics by Pseudomonas putida GJ31: assembled route for chlorobenzene degradation encoded by clusters on plasmid pKW1 and the chromosome.
Pseudomonas putida GJ31 has been reported to grow on chlorobenzene using a meta-cleavage pathway with chlorocatechol 2,3-dioxygenase (CbzE) as a key enzyme. The CbzE-encoding gene was found to be localized on the 180 kb plasmid pKW1 in a cbzTEXGS cluster, which is flanked by transposases and encodes only a partial (chloro)catechol meta-cleavage pathway comprising ferredoxin reductase, chlorocatechol 2,3-dioxygenase, an unknown protein, 2-hydroxymuconic semialdehyde dehydrogenase and glutathione S-transferase. Downstream of cbzTEXGS are located cbzJ, encoding a novel type of 2-hydroxypent-2,4-dienoate hydratase, and a transposon region highly similar to Tn5501. Upstream of cbzTEXGS, traNEOFG transfer genes were found. The search for gene clusters possibly completing the (chloro)catechol metabolic pathway of GJ31 revealed the presence of two additional catabolic gene clusters on pKW1. The mhpRBCDFETP cluster encodes enzymes for the dissimilation of 2,3-dihydroxyphenylpropionate in a novel arrangement characterized by the absence of a gene encoding 3-(3-hydroxyphenyl)propionate monooxygenase and the presence of a GntR-type regulator, whereas the nahINLOMKJ cluster encodes part of the naphthalene metabolic pathway. Transcription studies supported their possible involvement in chlorobenzene degradation. The upper pathway cluster, comprising genes encoding a chlorobenzene dioxygenase and a chlorobenzene dihydrodiol dehydrogenase, was localized on the chromosome. A high level of transcription in response to chlorobenzene revealed it to be crucial for chlorobenzene degradation. The chlorobenzene degradation pathway in strain GJ31 is thus a mosaic encoded by four gene clusters.
Kunze
Markus
M
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
Zerlin
Kay F
KF
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
Retzlaff
Alexander
A
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
Pohl
Jens O
JO
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
Schmidt
Eberhard
E
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
Janssen
Dick B
DB
Department of Biochemistry, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, 9747 AG Groningen, The Netherlands.
Vilchez-Vargas
Ramiro
R
Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany.
Pieper
Dietmar H
DH
Department of Microbial Pathogenesis, Helmholtz Centre for Infection Research, D-38124 Braunschweig, Germany.
Reineke
Walter
W
Bergische Universität Wuppertal, Chemical Microbiology, D-42097 Wuppertal, Germany.
D001483:Base Sequence; D001673:Biodegradation, Environmental; D002722:Chlorobenzenes / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000235:genetics; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D005810:Multigene Family; D010802:Phylogeny; D010957:Plasmids / Q000235:genetics; D016958:Pseudomonas putida / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*
D002722:Chlorobenzenes; D017931:DNA Primers; D004269:DNA, Bacterial; D049308:Dioxygenases; C053101:catechol oxygenase II; C083582:3-carboxyethylcatechol 2,3-dioxygenase; C031294:chlorobenzene