Team:Uppsala/toxin-antitoxin-system

From 2013.igem.org

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                                                 <li><a href="https://2013.igem.org/Team:Uppsala/metabolic-engineering">Metabolic engineering</a>
                                                 <li><a href="https://2013.igem.org/Team:Uppsala/metabolic-engineering">Metabolic engineering</a>
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                                                                 <li><a href="https://2013.igem.org/Team:Uppsala/p-coumaric-acid">p-Coumaric acid</a></li>
                                                                 <li><a href="https://2013.igem.org/Team:Uppsala/resveratrol">Resveratrol</a></li>
                                                                 <li><a href="https://2013.igem.org/Team:Uppsala/resveratrol">Resveratrol</a></li>
<li><a href="https://2013.igem.org/Team:Uppsala/lycopene">Lycopene</a></li>
<li><a href="https://2013.igem.org/Team:Uppsala/lycopene">Lycopene</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/modeling" id="list_type1"><img class="nav-text" src="https://static.igem.org/mediawiki/2013/6/63/Uppsala2013_Modeling.png"></a>
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<li><a href="https://2013.igem.org/Team:Uppsala/P-Coumaric-acid-pathway">P-Coumaric acid</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/P-Coumaric-acid-pathway">Kinetic model</a></li>
<li><a href="https://2013.igem.org/Team:Uppsala/modeling-tutorial">Modeling tutorial </a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/toxicity-model">Toxicity model</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/public-opinion">Public opinion </a></li>
<li><a href="https://2013.igem.org/Team:Uppsala/public-opinion">Public opinion </a></li>
                                                 <li><a href="https://2013.igem.org/Team:Uppsala/Outreach">High school & media </a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/bioart">BioArt</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/LactonutritiousWorld">A LactoWorld</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/killswitches">Killswitches</a></li>
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<li><a href="https://2013.igem.org/Team:Uppsala/realization">Patent</a></li>
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Revision as of 19:45, 27 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] . We have provided the toxin-antitoxin system both with and without a natural putative promoter.

Biobricks

  • BBa_K1033259 - antitoxin system from lactobacillus plantarum Toxin
  • BBa_K1033260 - antitoxin system from Lactobacillus plantarum Toxin
  • References:

    [1] 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