mazEF: a chromosomal toxin-antitoxin module that triggers programmed cell death in bacteria.

mazEF is a toxin-antitoxin module located on the Escherichia coli chromosome and that of some other bacteria, including pathogens. mazF specifies for a stable toxin, MazF, and mazE specifies for a labile antitoxin, MazE, that antagonizes MazF. MazF is a sequence-specific mRNA endoribonuclease that initiates a programmed cell death pathway in response to various stresses. The mazEF-mediated death pathway can act as a defense mechanism that prevents the spread of bacterial phage infection, allowing bacterial populations to behave like multicellular organisms.