Characterization of a Gene Cluster Involved in 4-Chlorocatechol Degradation by Pseudomonas reinekei MT1

Department of Microbial Pathogenesis, HZI Helmholtz Centre for Infection Research, Braunschweig, Germany.
Journal of bacteriology (Impact Factor: 2.81). 06/2009; 191(15):4905-15. DOI: 10.1128/JB.00331-09
Source: PubMed


Pseudomonas reinekei MT1 has previously been reported to degrade 4- and 5-chlorosalicylate by a pathway with 4-chlorocatechol, 3-chloromuconate,
4-chloromuconolactone, and maleylacetate as intermediates, and a gene cluster channeling various salicylates into an intradiol
cleavage route has been reported. We now report that during growth on 5-chlorosalicylate, besides a novel (chloro)catechol
1,2-dioxygenase, C12OccaA, a novel (chloro)muconate cycloisomerase, MCIccaB, which showed features not yet reported, was induced. This cycloisomerase, which was practically inactive with muconate,
evolved for the turnover of 3-substituted muconates and transforms 3-chloromuconate into equal amounts of cis-dienelactone and protoanemonin, suggesting that it is a functional intermediate between chloromuconate cycloisomerases and
muconate cycloisomerases. The corresponding genes, ccaA (C12OccaA) and ccaB (MCIccaB), were located in a 5.1-kb genomic region clustered with genes encoding trans-dienelactone hydrolase (ccaC) and maleylacetate reductase (ccaD) and a putative regulatory gene, ccaR, homologous to regulators of the IclR-type family. Thus, this region includes genes sufficient to enable MT1 to transform
4-chlorocatechol to 3-oxoadipate. Phylogenetic analysis showed that C12OccaA and MCIccaB are only distantly related to previously described catechol 1,2-dioxygenases and muconate cycloisomerases. Kinetic analysis
indicated that MCIccaB and the previously identified C12OsalD, rather than C12OccaA, are crucial for 5-chlorosalicylate degradation. Thus, MT1 uses enzymes encoded by a completely novel gene cluster for degradation
of chlorosalicylates, which, together with a gene cluster encoding enzymes for channeling salicylates into the ortho-cleavage pathway, form an effective pathway for 4- and 5-chlorosalicylate mineralization.

Download full-text


Available from: Howard Junca, Feb 28, 2014
  • Source
    • "The genes cphC-I and cphC-II encode putative monooxygenase, whereas cphF-1 and cphF-11 encode putative maleylacetate reductase and cphB encodes a NADH:flavin adenine dinucleotide oxidoreductase. The roles of the remaining genes in the cph gene cluster have yet to be determined [112]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Chlorophenols (CPs) and their derivatives are persistent environmental pollutants which are used in the manufacture of dyes, drugs, pesticides and other industrial products. CPs, which include monochlorophenols, polychlorophenols, chloronitrophenols, chloroaminophenols and chloromethylphenols, are highly toxic to living beings due to their carcinogenic, mutagenic and cytotoxic properties. Several physico-chemical and biological methods have been used for removal of CPs from the environment. Bacterial degradation has been considered a cost-effective and eco-friendly method of removing CPs from the environment. Several bacteria that use CPs as their sole carbon and energy sources have been isolated and characterized. Additionally, the metabolic pathways for degradation of CPs have been studied in bacteria and the genes and enzymes involved in the degradation of various CPs have been identified and characterized. This review describes the biochemical and genetic basis of the degradation of CPs and their derivatives.
    Microbial Cell Factories 03/2014; 13(1):31. DOI:10.1186/1475-2859-13-31 · 4.22 Impact Factor
  • Source
    • "Hollender et al. (1997) reported the degradation of 4-chlorophenol via the formation of 4-chlorocatechol. Literature studies showed that 4- chlorocatechol was degraded either via the ortho -cleavage pathway or the meta-cleavage pathway (Cámara et al. 2009; Nikodem et al. 2003; Hollender et al. 1997). In the orthocleavage pathway, 4-chlorocatechol was cleaved into 3- chloro-cis ,cis -muconate by a 4-chlorocatechol-1,2-doixy- genase (Nikodem et al. 2003). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Burkholderia sp. RKJ 800 utilized 4-chloro-2-aminophenol (4C2AP) as the sole carbon and energy source and degraded it with release of chloride and ammonium ions. The metabolic pathway of degradation of 4C2AP was studied and a novel intermediate, 4-chlorocatechol was identified as a major degradation product of 4C2AP using high-performance liquid chromatography and gas chromatography-mass spectrometry. Enzyme activities for 4C2AP-deaminase and 4-chlorocatechol-1,2-dioxygenase were detected in the crude extracts of the 4C2AP-induced cells of strain RKJ 800. The activity of the 4C2AP-deaminase confirmed the formation of 4-chlorocatechol from 4C2AP and the 4-chlorocatechol-1,2-dioxygenase activity suggested the cleavage of 4-chlorocatechol into 3-chloro-cis,cis-muconate. On the basis of the identified metabolites, we have proposed a novel degradation pathway of 4C2AP for Burkholderia sp. RKJ 800. Furthermore, the potential of Burkholderia sp. RKJ 800 to degrade 4C2AP in soil was also investigated using microcosm studies under laboratory conditions. The results of microcosm studies conclude that Burkholderia sp. RKJ 800 was able to degrade 4C2AP in soil and may be used to remediate 4C2AP-contaminated site. This is the first report of (1) the formation of 4-chlorocatechol and 3-chloro-cis,cis-muconate in the degradation pathway of 4C2AP and (2) bioremediation of 4C2AP by any bacterium.
    Environmental Science and Pollution Research 09/2013; 21(3). DOI:10.1007/s11356-013-2167-y · 2.83 Impact Factor
  • Source
    • "Enhanced degradation avoids accumulation of toxic metabolic intermediates such as catechols [5], [39]. The toxicity of aromatic compounds and their metabolic intermediates for strain LB400 has been reported [9], [31], [35]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Genome characterization of the model PCB-degrading bacterium Burkholderia xenovorans LB400 revealed the presence of eleven central pathways for aromatic compounds degradation, among them, the homogentisate and the homoprotocatechuate pathways. However, the functionality of these central pathways in strain LB400 has not been assessed and related peripheral pathways has not been described. The aims of this study were to determine the functionality of the homogentisate and homoprotocatechuate central pathways in B. xenovorans LB400 and to establish their role in 3-hydroxyphenylacetate (3-HPA) and 4-hydroxyphenylacetate (4-HPA) catabolism. Strain LB400 was able to grow using 3-HPA and 4-HPA as sole carbon source. A genomic search in LB400 suggested the presence of mhaAB and hpaBC genes clusters encoding proteins of the 3-hydroxyphenylacetate and 4-hydroxyphenylacetate peripheral pathways. LB400 cells grown with 3-HPA and 4-HPA degraded homogentisate and homoprotocatechuate and showed homogentisate 1,2-dioxygenase and homoprotocatechuate 2,3-dioxygenase activities. Transcriptional analyses by RT-PCR showed the expression of two chromosomally-encoded homogentisate dioxygenases (BxeA2725 and BxeA3900) and the hpaD gene encoding the homoprotocatechuate 2,3-dioxygenase during 3-HPA and 4-HPA degradation. The proteome analyses by two-dimensional polyacrilamide gel electrophoresis of B. xenovorans LB400 grown in 3-HPA and 4-HPA showed the induction of fumarylacetoacetate hydrolase HmgB (BxeA3899). This study revealed that strain LB400 used both homogentisate and homoprotocatechuate ring-cleavage pathways for 3- hydroxyphenylacetate and 4-hydroxyphenylacetate catabolism and that these four catabolic routes are functional, confirming the metabolic versatility of B. xenovorans LB400.
    PLoS ONE 03/2011; 6(3):e17583. DOI:10.1371/journal.pone.0017583 · 3.23 Impact Factor
Show more