Difference between revisions of "Part:BBa K4604011"

  Toxin-antitoxin systems (TA-systems) play a crucial role in plasmid stability for naturally occurring plasmids. Usually, the toxin targets essential cellular functions and causes growth arrest or cell death, to which the antitoxin acts as a counterpart. Toxin and antitoxin exhibit differences in their stability and lifespan. While the antitoxin has a shortened lifespan due to its sensitivity to degradation, the toxin has a longer lifespan and is more stable. If the plasmid that contains the TA-system is lost, the antitoxin is rapidly degraded and the toxin concentration increases, leading to cell death. Therefore, when first discovered, TA systems were called “addiction modules” that ensure plasmid retention. The labile MazE (antitoxin) acts as a neutralizer to the stable MazF (toxin), which is an endoribonuclease. When MazF is present freely in the cell it cuts cellular RNA which ultimately leads to cell death.