Autoregulation of the pTF-FC2 proteic poison-antidote plasmid addiction system (pas) is essential for plasmid stabilization.
The pasABC genes of the proteic plasmid addiction system of broad-host-range plasmid pTF-FC2 were autoregulated. The PasA antidote was able to repress the operon 25-fold on its own, and repression was increased to 100-fold when the PasB toxin was also present. Autoregulation appears to be an essential requirement for pas-mediated plasmid stabilization because when the pas genes were placed behind the isopropyl-beta-D-thiogalactopyranoside (IPTG)-regulated tac promoter, they were unable to stabilize a heterologous test plasmid.
Smith
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Department of Microbiology, University of Cape Town, Rondebosch 7700, South Africa.
Rawlings
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D000931:Antidotes / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis*; D001427:Bacterial Toxins / Q000096:biosynthesis* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D010957:Plasmids / Q000235:genetics*; D011401:Promoter Regions, Genetic
D000931:Antidotes; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C110604:PasA protein, Plasmid pTF-FC2; C110605:PasB protein, Thiobacillus ferrooxidans; C110606:PasC protein, Thiobacillus ferrooxidans