Enterococcus faecalis plasmid pAD1-encoded Fst toxin affects membrane permeability and alters cellular responses to lantibiotics

J Bacteriol. 2003 Apr;185(7):2169-77. doi: 10.1128/JB.185.7.2169-2177.2003.


Fst is a peptide toxin encoded by the par toxin-antitoxin stability determinant of Enterococcus faecalis plasmid pAD1. Intracellular overproduction of Fst resulted in simultaneous inhibition of all cellular macromolecular synthesis concomitant with cell growth inhibition and compromised the integrity of the cell membrane. Cells did not lyse or noticeably leak intracellular contents but had specific defects in chromosome partitioning and cell division. Extracellular addition of synthetic Fst had no effect on cell growth. Spontaneous Fst-resistant mutants had a phenotype consistent with changes in membrane composition. Interestingly, overproduction of Fst sensitized cells to the lantibiotic nisin, and Fst-resistant mutants were cross-resistant to nisin and the pAD1-encoded cytolysin.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Anti-Bacterial Agents / pharmacology*
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Toxins / genetics*
  • Bacterial Toxins / metabolism
  • Bacterial Toxins / pharmacology*
  • Cell Division / genetics
  • Cell Membrane / drug effects
  • Cell Membrane Permeability / drug effects*
  • Cytotoxins / pharmacology
  • DNA, Bacterial / biosynthesis
  • DNA, Bacterial / genetics
  • Enterococcus faecalis / cytology
  • Enterococcus faecalis / drug effects*
  • Enterococcus faecalis / physiology
  • Glycine / pharmacology
  • Molecular Sequence Data
  • Mutation
  • Nisin / pharmacology
  • Plasmids / genetics*
  • RNA, Bacterial / biosynthesis
  • RNA, Bacterial / genetics


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Bacterial Toxins
  • Cytotoxins
  • DNA, Bacterial
  • RNA, Bacterial
  • fst toxin, Enterococcus faecalis
  • Nisin
  • Glycine