1. Accumulation of Mn(II) in Deinococcus radiodurans facilitates gamma-radiation resistance.
- Author
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Daly MJ, Gaidamakova EK, Matrosova VY, Vasilenko A, Zhai M, Venkateswaran A, Hess M, Omelchenko MV, Kostandarithes HM, Makarova KS, Wackett LP, Fredrickson JK, and Ghosal D
- Subjects
- Culture Media, DNA Repair, DNA, Bacterial, Deinococcus physiology, Deinococcus ultrastructure, Iron physiology, Reactive Oxygen Species metabolism, Superoxide Dismutase metabolism, Deinococcus radiation effects, Manganese physiology, Radiation Tolerance physiology
- Abstract
Deinococcus radiodurans is extremely resistant to ionizing radiation. How this bacterium can grow under chronic gamma radiation [50 grays (Gy) per hour] or recover from acute doses greater than 10 kGy is unknown. We show that D. radiodurans accumulates very high intracellular manganese and low iron levels compared with radiation-sensitive bacteria and that resistance exhibits a concentration-dependent response to manganous chloride [Mn(II)]. Among the most radiation-resistant bacterial groups reported, Deinococcus, Enterococcus, Lactobacillus, and cyanobacteria accumulate Mn(II). In contrast, Shewanella oneidensis and Pseudomonas putida have high iron but low intracellular manganese concentrations and are very sensitive. We propose that Mn(II) accumulation facilitates recovery from radiation injury.
- Published
- 2004
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