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
Article first published online: 15 JAN 2007
Volume 63, Issue 5, pages 1495–1507, March 2007
How to Cite
Velayudhan, J., Castor, M., Richardson, A., Main-Hester, K. L. and Fang, F. C. (2007), 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. Molecular Microbiology, 63: 1495–1507. doi: 10.1111/j.1365-2958.2007.05600.x
- Issue published online: 15 JAN 2007
- Article first published online: 15 JAN 2007
- Accepted 9 January, 2007.
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+.