Identification and characterization of Tn4656, a novel class II transposon carrying a set of toluene-degrading genes from TOL plasmid pWW53.
It has been reported that the toluene-degrading (xyl) genes from Pseudomonas putida plasmid pWW53 are able to translocate to broad-host-range drug resistance plasmid RP4, and pWW53-4 is one of the smallest RP4 derivatives (H. Keil, S. Keil, R. W. Pickup, and P. A. Williams, J. Bacteriol. 164:887-895, 1985). Our investigation of pWW53-4 in this study demonstrated that such a translocated region that is 39 kb long is a transposon. This mobile element, Tn4656, was classified as a class II transposon since its transposition occurred by a two-step process: transposase (TnpA)-mediated formation of the cointegrate and resolvase (TnpR)-mediated site-specific resolution of the cointegrate at the two copies of the res site. The Tn4656 TnpA and TnpR functions encoded in the rightmost 4-kb region were found to be exchangeable with those specified by other Tn1721-related class II transposons, including another toluene transposon, Tn4653. Sequence analysis of the transposition-related genes and sites of Tn4656 also supported the hypothesis that this transposon is closely related to the Tn1721-related transposons. The lower transposition frequency of Tn4656 has been suggested to be due to the unique nucleotide sequence of one of the terminal 39-bp inverted repeats.
Tsuda
M
M
Department of Environmental Life Science, Graduate School of Life Sciences, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan. mtsuda@ige.tohoku.ac.jp
Genka
H
H
D001426:Bacterial Proteins; D004251:DNA Transposable Elements / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D008969:Molecular Sequence Data; D010957:Plasmids; D016958:Pseudomonas putida / Q000235:genetics / Q000378:metabolism; D012689:Sequence Homology, Nucleic Acid; D014050:Toluene / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D015534:Trans-Activators; D014157:Transcription Factors; C074322:XylR protein, Pseudomonas; C078720:XylS protein, Pseudomonas putida; D014050:Toluene