Cloning and characterization of the ColE7 plasmid.

  title={Cloning and characterization of the ColE7 plasmid.},
  author={Kin Fu Chak and Wen Shuo Kuo and Feng Lu and Richard James},
  journal={Journal of general microbiology},
  volume={137 1},
The 6.2 kb ColE7-K317 plasmid was mapped and the DNA fragments of the colicin E7 operon subcloned into pUC18 and pUC19. The size of the functional colicin E7 operon deduced by subcloning was 2.3 kb. The colicin E7 gene product was purified by carboxymethylcellulose chromatography. Both colicin E7 and E9 were demonstrated to exhibit a non-specific DNAase-type activity by in vitro biological assay. The molecular mass of colicin E7 was 61 kDa, as determined by SDS-PAGE. From DNA sequence data, the… CONTINUE READING