Restoration of growth by manganese in a mutant strain of Escherichia coli lacking most known iron and manganese uptake systems
- 311 Downloads
The interplay of manganese and iron homeostasis and oxidative stress in Escherichia coli can give important insights into survival of bacteria in the phagosome and under differing iron or manganese bioavailabilities. Here, we characterized a mutant strain devoid of all know iron/manganese-uptake systems relevant for growth in defined medium. Based on these results an exit strategy enabling the cell to cope with iron depletion and use of manganese as an alternative for iron could be shown. Such a strategy would also explain why E. coli harbors some iron- or manganese-dependent iso-enzymes such as superoxide dismutases or ribonucleotide reductases. The benefits for gaining a means for survival would be bought with the cost of less efficient metabolism as indicated in our experiments by lower cell densities with manganese than with iron. In addition, this strain was extremely sensitive to the metalloid gallium but this gallium toxicity can be alleviated by low concentrations of manganese.
KeywordsIron Manganese SOD Gallium
This work was supported by start-up funds at the University of Copenhagen for C.R. and by the Deutsche Forschungsgemeinschaft by Grant GR2061/1-2 to G. G. We thank Grit Schleuder for skilful technical assistance.
- Chitambar CR (2004) Apoptotic mechanisms of gallium nitrate: basic and clinical investigations. Oncology (Williston Park) 18:39–44Google Scholar
- Martin JE, Imlay JA (2011) The alternative aerobic ribonucleotide reductase of Escherichia coli, NrdEF, is a manganese-dependent enzyme that enables cell replication during periods of iron starvation. Mol Microbiol 80:319–334. doi: 10.1111/j.1365-2958.2011.07593.x CrossRefPubMedPubMedCentralGoogle Scholar
- Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual, 2nd edn. Cold Spring Harbor Laboratory Press, Cold Spring HarborGoogle Scholar