Characterization of the 450-kb Linear Plasmid in a Polychlorinated Biphenyl Degrader, Rhodococcus sp. Strain RHA1
AUTOR(ES)
Shimizu, Satoru
FONTE
American Society for Microbiology
RESUMO
A strong polychlorinated biphenyl (PCB) degrader, Rhodococcus sp. strain RHA1, has diverse biphenyl/PCB degradative genes and harbors huge linear plasmids, including pRHL1 (1,100 kb), pRHL2 (450 kb), and pRHL3 (330 kb). The diverse degradative genes are distributed mainly on the pRHL1 and pRHL2 plasmids. In this study, the structural and functional characteristics of pRHL2 were determined. We constructed a physical map of pRHL2, and the degradative enzyme genes, including bphB2, etbD2, etbC, bphDEF, bphC2, and bphC4, were localized in three regions. Conjugal transfer of pRHL2 between RHA1 mutant derivatives was observed at a frequency of 7.5 × 10−5 transconjugant per recipient. These results suggested that the linear plasmid is a possible determinant of propagation of the diverse degradative genes in rhodococci. The termini of pRHL2 were cloned and sequenced. The left and right termini of pRHL2 had 3-bp perfect terminal inverted repeats and were not as similar to each other (64% identity) as the known actinomycete linear replicons are. Southern hybridization analysis with pRHL2 terminal probes suggested that the right terminus of pRHL2 is similar to pRHL1 and pRHL3 termini. Retardation of both terminal fragments in the gel shift assay indicated that each terminus of pRHL2 is linked to a protein. We suggest that pRHL2 has invertron termini, as has been reported previously for Streptomyces linear replicons.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=92831Documentos Relacionados
- Two Nearly Identical Aromatic Compound Hydrolase Genes in a Strong Polychlorinated Biphenyl Degrader, Rhodococcus sp. Strain RHA1
- 2-Hydroxypenta-2,4-dienoate Metabolic Pathway Genes in a Strong Polychlorinated Biphenyl Degrader, Rhodococcus sp. Strain RHA1
- Cloning and Characterization of Benzoate Catabolic Genes in the Gram-Positive Polychlorinated Biphenyl Degrader Rhodococcus sp. Strain RHA1
- Characterization of biphenyl catabolic genes of gram-positive polychlorinated biphenyl degrader Rhodococcus sp. strain RHA1.
- Characterization of Transcriptional Regulatory Genes for Biphenyl Degradation in Rhodococcus sp. Strain RHA1