"
Team:Uppsala/toxin-antitoxin-system
From 2013.igem.org
(Difference between revisions)
| Line 70: | Line 70: | ||
<li><a href="https://2013.igem.org/Team:Uppsala/chromoproteins">Chromoproteins</a></li> | <li><a href="https://2013.igem.org/Team:Uppsala/chromoproteins">Chromoproteins</a></li> | ||
<li><a href="https://2013.igem.org/Team:Uppsala/safety-experiment">Safety experiment</a></li> | <li><a href="https://2013.igem.org/Team:Uppsala/safety-experiment">Safety experiment</a></li> | ||
| - | <li><a href="https://2013.igem.org/Team:Uppsala/ | + | <li><a href="https://2013.igem.org/Team:Uppsala/results">Results</a></li> |
| Line 89: | Line 89: | ||
</ul></li> | </ul></li> | ||
| - | <li><a href="https://2013.igem.org/Team:Uppsala/ | + | <li><a href="https://2013.igem.org/Team:Uppsala/human-practice" id="list_type3"><img class="nav-text" src="https://static.igem.org/mediawiki/2013/b/b8/Uppsala2013_HP.png"></a> |
<ul> | <ul> | ||
| - | <li><a href="https://2013.igem.org/Team:Uppsala/ | + | <li><a href="https://2013.igem.org/Team:Uppsala/yoghurt">Yoghurt +</a></li> |
<li><a href="https://2013.igem.org/Team:Uppsala/synbioday">SynBioDay</a></li> | <li><a href="https://2013.igem.org/Team:Uppsala/synbioday">SynBioDay</a></li> | ||
| - | <li><a href="https://2013.igem.org/Team:Uppsala/ | + | <li><a href="https://2013.igem.org/Team:Uppsala/biosafety-and-ethics">Biosafety and ethics</a></li> |
| - | <li><a href="https://2013.igem.org/Team:Uppsala/ | + | <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> | <li><a href="https://2013.igem.org/Team:Uppsala/Outreach">High school & media </a></li> | ||
| Line 110: | Line 110: | ||
</div> | </div> | ||
| - | |||
| - | |||
<div id="main_content"> <!-- Put content here --> | <div id="main_content"> <!-- Put content here --> | ||
Revision as of 08:59, 29 September 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.References:
http://mic.sgmjournals.org/content/151/2/421.long (1)
