Location of Repository

Cloning and sequencing of a dehalogenase gene encoding an enzyme with hydrolase activity involved in the degradation of gamma-hexachlorocyclohexane in Pseudomonas paucimobilis.

By Y Nagata, T Nariya, R Ohtomo, M Fukuda, K Yano and M Takagi

Abstract

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted by two steps of dehydrochlorination to a chemically unstable intermediate, 1,3,4,6-tetrachloro-1,4-cyclohexadiene (1,4-TCDN), which is then metabolized to 2,5-dichloro-2,5-cyclohexadiene-1,4-diol (2,5-DDOL) by two steps of hydrolytic dehalogenation via the chemically unstable intermediate 2,4,5-trichloro-2,5-cyclohexadiene-1-ol (2,4,5-DNOL). To clone a gene encoding the enzyme responsible for the conversion of the chemically unstable intermediates 1,4-TCDN and 2,4,5-DNOL, a genomic library of P. paucimobilis UT26 was constructed in Pseudomonas putida PpY101LA into which the linA gene had been introduced by Tn5. An 8-kb BglII fragment from one of the cosmid clones, which could convert gamma-HCH to 2,5-DDOL, was subcloned, and subsequent deletion analyses revealed that a ca. 1.1-kb region was responsible for the activity. Nucleotide sequence analysis revealed an open reading frame (designated the linB gene) of 885 bp within the region. The deduced amino acid sequence of LinB showed significant similarity to hydrolytic dehalogenase, DhlA (D. B. Janssen, F. Pries, J. van der Ploeg, B. Kazemier, P. Terpstra, and B. Witholt, J. Bacteriol. 171:6791-6799, 1989). The protein product of the linB gene was 32 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Not only 1-chlorobutane but also 1-chlorodecane (C10) and 2-chlorobutane, which are poor substrates for other dehalogenases, were good substrates for LinB, suggesting that LinB may be a member of haloalkane dehalogenases with broad-range specificity for substrates

Topics: Research Article
Year: 1993
OAI identifier: oai:pubmedcentral.nih.gov:206747
Provided by: PubMed Central
Sorry, our data provider has not provided any external links therefor we are unable to provide a PDF.

Suggested articles


To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.