The stationary-phase sigma factor sigma(S) is responsible for the resistance of Escherichia coli stationary-phase cells to mazEF-mediated cell death.

Escherichia coli mazEF is a toxin-antitoxin gene module that mediates cell death during exponential-phase cellular growth through either reactive oxygen species (ROS)-dependent or ROS-independent pathways. Here, we found that the stationary-phase sigma factor sigma(S) was responsible for the resistance to mazEF-mediated cell death during stationary growth phase. Deletion of rpoS, the gene encoding sigma(S) from the bacterial chromosome, permitted mazEF-mediated cell death during stationary growth phase.