title: Transcription Factors That Defend Bacteria Against Reactive Oxygen Species.
abstract: Bacteria live in a toxic world in which their competitors excrete hydrogen peroxide or superoxide-generating redox-cycling compounds. They protect themselves by activating regulons controlled by the OxyR, PerR, and SoxR transcription factors. OxyR and PerR sense peroxide when it oxidizes key thiolate or iron moieties, respectively; they then induce overlapping sets of proteins that defend their vulnerable metalloenzymes. An additional role for OxyR in detecting electrophilic compounds is possible. In some nonenteric bacteria, SoxR appears to control the synthesis and export of redox-cycling compounds, whereas in the enteric bacteria it defends the cell against the same agents. When these compounds oxidize its iron-sulfur cluster, SoxR induces proteins that exclude, excrete, or modify them. It also induces enzymes that defend the cell against the superoxide that such compounds make. Recent work has brought new insight into the biochemistry and physiology of these responses, and comparative studies have clarified their evolutionary histories.
authors.affiliation: Department of Microbiology, University of Illinois, Urbana, Illinois 61801; email: jimlay@illinois.edu.
authors.forename: James A
authors.initials: JA
authors.lastname: Imlay
mesh_terms: D001419:Bacteria / Q000145:classification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism; D010084:Oxidation-Reduction; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D017382:Reactive Oxygen Species; D014157:Transcription Factors; D013481:Superoxides; D006861:Hydrogen Peroxide
keywords: OxyR; PerR; SoxR; hydrogen peroxide; reactive oxygen species; superoxide