Conditional cooperativity in toxin-antitoxin regulation prevents random toxin activation and promotes fast translational recovery

Ilaria Cataudella, Ala Trusina, Kim Sneppen, Kenn Gerdes, Namiko Mitarai

59 Citationer (Scopus)

Abstract

Many toxin-antitoxin (TA) loci are known to strongly repress their own transcription. This auto-inhibition is often called `conditional cooperativity' as it relies on cooperative binding of TA complexes to operator DNA that occurs only when toxins are in a proper stoichiometric relationship with antitoxins. There has recently been an explosion of interest in TA systems due to their role in bacterial persistence, however the role of conditional cooperativity is still unclear. We reveal the biological function of conditional cooperativity by constructing a mathematical model of the well studied TA system, relBE of Escherichia coli. We show that the model with the in vivo and in vitro established parameters reproduces experimentally observed response to nutritional stress. We further demonstrate that conditional cooperativity stabilizes the level of antitoxin in rapidly growing cells such that random induction of relBE is minimized. At the same time it enables quick removal of free toxin when the starvation is terminated.
OriginalsprogEngelsk
TidsskriftNucleic Acids Research
Vol/bind40
Udgave nummer14
Sider (fra-til)6424-6434
Antal sider11
ISSN0305-1048
DOI
StatusUdgivet - aug. 2012
Udgivet eksterntJa

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