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Team:Uppsala/toxin-antitoxin-system
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<h1> A natural toxin-antitoxin from lactobacillus plantarum </h1> | <h1> A natural toxin-antitoxin from lactobacillus plantarum </h1> | ||
| - | We have taken the Pem toxin-antitoxin system from plasmid p256 that was originally isolated from lactobacillus plantarum NC7. The system consists of a single operon and consists of two ORFs, one for the toxin and antitoxin respectively. Pem on p256 has been shown to increase segregational stability under non-selective pressure. The system has experimentally been shown to allow 88-100% retention of a plasmid after 80 generations | + | We have taken the Pem toxin-antitoxin system from plasmid p256 that was originally isolated from lactobacillus plantarum NC7. The system consists of a single operon and consists of two ORFs, one for the toxin and antitoxin respectively. Pem on p256 has been shown to increase segregational stability under non-selective pressure. The system has experimentally been shown to allow 88-100% retention of a plasmid after 80 generations<sup> <a href="#refpoint"> [1] </a> </sup. We have provided the toxin-antitoxin system both with and without a natural putative promoter. |
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<li> <a href="http://parts.igem.org/Part:BBa_K1033260">BBa_K1033260</a> - antitoxin system from Lactobacillus plantarum Toxin<br> </li> | <li> <a href="http://parts.igem.org/Part:BBa_K1033260">BBa_K1033260</a> - antitoxin system from Lactobacillus plantarum Toxin<br> </li> | ||
| - | <h1> References: </h1> | + | <h1> References: </h1> <a id="refpoint"> </a> |
| - | http://mic.sgmjournals.org/content/151/2/421.long | + | Plasmid p256 from Lactobacillus plantarum represents a new type of replicon in lactic acid bacteria, and contains a toxin–antitoxin-like plasmid maintenance system, Microbiology, Elisabeth Sorvig et al. September 30 2004 |
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| + | Länk till:http://mic.sgmjournals.org/content/151/2/421.long | ||
Revision as of 18:08, 3 October 2013
Toxin-antitoxin system
Keep your plasmids without antibiotic resistance
One of the challenges when creating synthetic systems in bacteria that serve a purpose besides increasing the fitness of the organism is that there is a negative selective pressure against keeping the system. Toxin-antitoxin systems can be used to make plasmids far more stabile without having to use antibiotics and antibiotic resistance. If a clone were to lose the plasmid, the toxin which usually has a longer half life than the antitoxin will kill the bacteria.
Above is an example of how a toxin-antitoxin system could be applied together with a gene X. If the gene is toxic or expressed strongly enough there will be a substantial evolutionary pressure to lose the plasmid during cell division. However if the gene is present on a plasmid with a toxin-antitoxin system would be lethal due to the loss of the antitoxin gene.
A natural toxin-antitoxin from lactobacillus plantarum
We have taken the Pem toxin-antitoxin system from plasmid p256 that was originally isolated from lactobacillus plantarum NC7. The system consists of a single operon and consists of two ORFs, one for the toxin and antitoxin respectively. Pem on p256 has been shown to increase segregational stability under non-selective pressure. The system has experimentally been shown to allow 88-100% retention of a plasmid after 80 generations [1]Biobricks
References:
Plasmid p256 from Lactobacillus plantarum represents a new type of replicon in lactic acid bacteria, and contains a toxin–antitoxin-like plasmid maintenance system, Microbiology, Elisabeth Sorvig et al. September 30 2004 Länk till:http://mic.sgmjournals.org/content/151/2/421.long
