Transposon-mediated mobilization of chromosomally located catabolic operons of the CAM plasmid by TOL plasmid transposon Tn4652 and CAM plasmid transposon Tn3614

Abstract

The CAM (camphor degradation) plasmid is integrated into the chromosome of Pseudomonas putida Paw-line strains and is not selftransferable as a plasmid via conjugation. Our results show that the mobilization of chromosomally located CAM and the integration of cam-operons into the chromosome of the new Cam+ transconjugants is a red-independent process mediated by transposons Tn4652 (17 kbp) and Tn3614 (7.2 kbp). Transposon Tn3674 is apparently identical to the left-hand and the right-hand sequences of the TOL plasmid pWW0 transposon Tn4654. The insertion of Tn407 inside the left-hand terminal IR of Tn4652 completely inhibited the mobilization of CAM. According to our data transposons Tn4652 and Tn3614 together with CAM plasmid catabolic operons are integrated into the chromosome. We propose that in pseudomonads the transposons Tn4652 and Tn3614 play a key role in the evolution and spread of new catabolic plasmids in nature.

Characterization of plasmid pSY3 in Sphingobium chungbukense DJ77

“…Bacterial transposons play an important role in the degradation of xenobiotic compounds, due to their catabolic activities. Maet and Heinaru (1994) reported that the transposons Tn4652 and Tn3614 play a key role in the evolution of Pseudomonas and spread of new catabolic plasmids in nature.…”