The role of ferritins in the physiology of Salmonella enterica sv. Typhimurium: a unique role for ferritin B in iron-sulphur cluster repair and virulence

Mol Microbiol. 2007 Mar;63(5):1495-507. doi: 10.1111/j.1365-2958.2007.05600.x.


Ferritins are ubiquitous iron (Fe) storage proteins that play a fundamental role in cellular Fe homeostasis. The enteric pathogen Salmonella enterica serovar Typhimurium possesses four ferritins: bacterioferritin, ferritin A, ferritin B and Dps. The haem-containing bacterioferritin (Bfr) accounts for the majority of stored Fe, followed by ferritin A (FtnA). Inactivation of bfr elevates the intracellular free Fe concentration and enhances susceptibility to H2O2 stress. The DNA-binding Dps protein provides protection from oxidative damage without affecting the steady-state intracellular free Fe concentration. FtnB appears to be particularly important for the repair of oxidatively damaged Fe-sulphur clusters of aconitase and, in contrast to Bfr and FtnA, is required for Salmonella virulence in mice. Moreover, ftnB and dps are repressed by the Fe-responsive regulator Fur and induced under conditions of Fe limitation, whereas bfr and ftnA are maximally expressed when Fe is abundant. The absence of a conserved ferroxidase domain and the potentiation of oxidative stress by FtnB in some strains lacking Dps suggest that FtnB serves as a facile cellular reservoir of Fe2+.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Aconitate Hydratase / metabolism*
  • Animals
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / physiology
  • Cytoplasm / chemistry
  • Female
  • Ferritins / genetics
  • Ferritins / physiology*
  • Gene Deletion
  • Gene Expression Regulation, Bacterial
  • Hydrogen Peroxide / pharmacology
  • Iron / metabolism
  • Liver / microbiology
  • Mice
  • Mice, Inbred C3H
  • Oxidative Stress
  • RNA, Bacterial / analysis
  • RNA, Messenger / analysis
  • Repressor Proteins / physiology
  • Salmonella Infections, Animal / microbiology
  • Salmonella typhimurium / pathogenicity*
  • Salmonella typhimurium / physiology*
  • Survival
  • Virulence


  • Anti-Bacterial Agents
  • Bacterial Proteins
  • RNA, Bacterial
  • RNA, Messenger
  • Repressor Proteins
  • ferric uptake regulating proteins, bacterial
  • Ferritins
  • Hydrogen Peroxide
  • Iron
  • Aconitate Hydratase