Master of Science (MS)
The gram-positive eubacterium Deinococcus radiodurans is widely recognized for its extreme resistance to various DNA-damaging conditions, such as desiccation and ionizing and ultraviolet radiation. D. radiodurans is one of only a few bacteria which encode two Dps (DNA protection during starvation) proteins. Here I report the cloning and purification of a more soluble Dps2, Ntrunc. Also, the initial characterization of a truncated Dps2, which lacks the C-terminal metal binding loop, shows that this region is important for proper oligomerization. Furthermore, Dps2 expression was found to be moderately induced when stressed with exogenous H2O2, and expression levels were not altered by excess iron or iron scarcity. Dps-1 was shown to compact the E. coli nucleoid, similar to the E. coli Dps, while Dps-2 is incapable of nucleoid condensation. I also began the localization of Dps2 in D. radiodurans, as it is predicted to have a signal peptide. While Dps-1 may play a role in iron homeostasis and local nucleoid architecture, the function of Dps-2 may serve as a first line of defense by protecting against exogenous ROS. Together these proteins may in part contribute to the ability of D. radiodurans to withstand such extreme environments.
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Reon, Brian, "Functional characterization of a non-cytoplasmically localized Dps protein from Deinococcus radiodurans" (2010). LSU Master's Theses. 2104.