Complete nucleotide sequence of TOL plasmid pDK1 provides evidence for evolutionary history of IncP-7 catabolic plasmids.
To understand the mechanisms for structural diversification of Pseudomonas-derived toluene-catabolic (TOL) plasmids, the complete sequence of a self-transmissible plasmid pDK1 with a size of 128,921 bp from Pseudomonas putida HS1 was determined. Comparative analysis revealed that (i) pDK1 consisted of a 75.6-kb IncP-7 plasmid backbone and 53.2-kb accessory gene segments that were bounded by transposon-associated regions, (ii) the genes for conjugative transfer of pDK1 were highly similar to those of MOB(H) group of mobilizable plasmids, and (iii) the toluene-catabolic (xyl) gene clusters of pDK1 were derived through homologous recombination, transposition, and site-specific recombination from the xyl gene clusters homologous to another TOL plasmid, pWW53. The minireplicons of pDK1 and its related IncP-7 plasmids, pWW53 and pCAR1, that contain replication and partition genes were maintained in all of six Pseudomonas strains tested, but not in alpha- or betaproteobacterial strains. The recipient host range of conjugative transfer of pDK1 was, however, limited to two Pseudomonas strains. These results indicate that IncP-7 plasmids are essentially narrow-host-range and self-transmissible plasmids that encode MOB(H) group-related transfer functions and that the host range of IncP-7-specified conjugative transfer was, unlike the situation in other well-known plasmids, narrower than that of its replication.
Yano
Hirokazu
H
Department of Environmental Life Sciences, Graduate School of Life Sciences, Tohoku University, Katahira, Sendai, Japan.
Miyakoshi
Masatoshi
M
Ohshima
Kenshiro
K
Tabata
Michiro
M
Nagata
Yuji
Y
Hattori
Masahira
M
Tsuda
Masataka
M
D001426:Bacterial Proteins / Q000235:genetics; D003227:Conjugation, Genetic; D004251:DNA Transposable Elements / Q000235:genetics; D019143:Evolution, Molecular; D008969:Molecular Sequence Data; D005810:Multigene Family; D010957:Plasmids / Q000235:genetics*; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D014050:Toluene / Q000378:metabolism*
D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D014050:Toluene