title: Plasmid-borne catabolism of methyl parathion and p-nitrophenol in Pseudomonas sp. strain WBC-3.
abstract: Pseudomonas sp. strain WBC-3 utilises methyl parathion (MP) or p-nitrophenol (PNP) as the sole source of carbon, nitrogen, and energy. A plasmid designated pZWL0 of approximately 70 kb in this strain was found to be responsible for MP and PNP degradation. This was based on the fact that the plasmid-cured strains showed PNP- MP- phenotype and the PNP+ MP+ phenotype could be conjugally transferred. We have also cloned a 3.4-kb HindIII fragment which exhibited methyl parathion hydrolase activity, which revealed a methyl parathion hydrolase (mph) gene whose DNA sequence is 99.5% identical to the recently identified mpd gene from Plesiomonas sp. M6 [C. Zhongli, L. Shunpeng, F. Guoping, Isolation of methyl parathion-degrading strain M6 and cloning of the methyl parathion hydrolase gene, Appl. Environ. Microbiol. 67 (2001) 4922-4925]. The mph gene was functionally expressed in Escherichia coli and the relative activities of the enzyme against different substrates were determined. The sequence alignment and phylogenetic analysis suggested that MPH and MPD evolved independently from other well-studied organophosphate hydrolases and may be originated from class B beta-lactamase family. Subsequently obtained a 6.5-kb KpnI and BamHI fragment containing the above HindIII fragment revealed that the mph gene was physically located in a typical transposon.
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Jun-Jie
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Su-Jun
authors.initials: SJ
authors.lastname: Wang
authors.forename: Xian-En
authors.initials: XE
authors.lastname: Zhang
authors.forename: Ning-Yi
authors.initials: NY
authors.lastname: Zhou
mesh_terms: D000595:Amino Acid Sequence; D001673:Biodegradation, Environmental; D002384:Catalysis; D020869:Gene Expression Profiling; D008743:Methyl Parathion / Q000493:pharmacokinetics*; D008969:Molecular Sequence Data; D009596:Nitrophenols / Q000493:pharmacokinetics*; D010755:Organophosphates / Q000493:pharmacokinetics; D010575:Pesticides / Q000493:pharmacokinetics; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics*; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: D009596:Nitrophenols; D010755:Organophosphates; D010575:Pesticides; D008743:Methyl Parathion; C495424:methyl parathion hydrolase, Pseudomonas; D010744:Phosphoric Monoester Hydrolases