The multifaceted capacity of Dps proteins to combat bacterial stress conditions: Detoxification of iron and hydrogen peroxide and DNA binding

Background: The widely expressed Dps proteins, so named after the DNA-binding properties of the first characterized member of the family in Escherichia coli, are considered major players in the bacterial response to stress. Scope of review: The review describes the distinctive features of the "ferritin-like" ferroxidation reaction, which uses hydrogen peroxide as physiological iron oxidant and therefore permits the concomitant removal of the two reactants that give rise to hydroxyl radicals via Fenton chemistry. It also illustrates the structural elements identified to date that render the interaction of some Dps proteins with DNA possible and outlines briefly the significance of Dps-DNA complex formation and of the Dps interaction with other DNA-binding proteins in relation to the organization of the nucleoid and microbial survival. General significance: Understanding in molecular terms the distinctive role of Dps proteins in bacterial resistance to general and specific stress conditions. Major conclusions: The state of the art is that the response to oxidative and peroxide-mediated stress is mediated directly by Dps proteins via their ferritin-like activity. In contrast, the response to other stress conditions derives from the concerted interplay of diverse interactions that Dps proteins may establish with DNA and with other DNA-binding proteins.