title: The extracellular death factor: physiological and genetic factors influencing its production and response in Escherichia coli.
abstract: Gene pairs specific for a toxin and its antitoxin are called toxin-antitoxin modules and are found on the chromosomes of many bacteria. The most studied of these modules is Escherichia coli mazEF, in which mazF encodes a stable toxin, MazF, and mazE encodes a labile antitoxin, MazE, which prevents the lethal effect of MazF. In a previous report from this laboratory, it was shown that mazEF-mediated cell death is a population phenomenon requiring a quorum-sensing peptide called the extracellular death factor (EDF). EDF is the linear pentapeptide NNWNN (32). Here, we further confirm that EDF is a signal molecule in a mixed population. In addition, we characterize some physiological conditions and genes required for EDF production and response. Furthermore, stress response and the gene specifying MazEF, the Zwf (glucose-6-phosphate dehydrogenase) gene, and the protease ClpXP are critical in EDF production. Significant strain differences in EDF production and response explain variations in the induction of mazEF-mediated cell death.
authors.affiliation: Department of Molecular Biology, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
authors.forename: Ilana
authors.initials: I
authors.lastname: Kolodkin-Gal
authors.forename: Hanna
authors.initials: H
authors.lastname: Engelberg-Kulka
mesh_terms: D017209:Apoptosis; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D049071:Endopeptidase Clp / Q000235:genetics / Q000378:metabolism; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D009842:Oligopeptides / Q000096:biosynthesis* / Q000235:genetics; D053038:Quorum Sensing
chemical_list: D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C422954:MazE protein, E coli; C422955:MazF protein, E coli; D009842:Oligopeptides; C528802:asparagyl-aspargyl-tryptophyl-asparagyl-asparagine; D005954:Glucosephosphate Dehydrogenase; D004722:Endoribonucleases; C483573:ClpXP protease, E coli; D049071:Endopeptidase Clp