OxyR2 Functions as a Three-state Redox Switch to Tightly Regulate Production of Prx2, a Peroxiredoxin of Vibrio vulnificus*

@article{Bang2016OxyR2FA,
  title={OxyR2 Functions as a Three-state Redox Switch to Tightly Regulate Production of Prx2, a Peroxiredoxin of Vibrio vulnificus*},
  author={Ye-Ji Bang and Zee-won Lee and Dukyun Kim and Inseong Jo and Nam-Chul Ha and Sang Ho Choi},
  journal={The Journal of Biological Chemistry},
  year={2016},
  volume={291},
  pages={16038 - 16047}
}
The bacterial transcriptional regulator OxyR is known to function as a two-state redox switch. OxyR senses cellular levels of H2O2 via a “sensing cysteine” that switches from the reduced to a disulfide state upon H2O2 exposure, inducing the expression of antioxidant genes. The reduced and disulfide states of OxyR, respectively, bind to extended and compact regions of DNA, where the reduced state blocks and the oxidized state allows transcription and further induces target gene expression by… 

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References

SHOWING 1-10 OF 29 REFERENCES
Distinct characteristics of OxyR2, a new OxyR‐type regulator, ensuring expression of Peroxiredoxin 2 detoxifying low levels of hydrogen peroxide in Vibrio vulnificus
TLDR
The oxyR2 mutation reduced cytotoxicity and growth during infection, indicating that OxyR2 is essential for the pathogenesis of V. vulnificus.
Structural details of the OxyR peroxide-sensing mechanism
TLDR
This study presents the first, to the authors' knowledge, full-length structures of peroxide-sensing transcription regulator OxyR together with an oxidation intermediate-mimicking structure and reveals a step-by-step molecular mechanism for OxyR from H2O2 sensing to structural changes for transcriptional activation.
Characterization of the Vibrio vulnificus 1-Cys Peroxiredoxin Prx3 and Regulation of Its Expression by the Fe-S Cluster Regulator IscR in Response to Oxidative Stress and Iron Starvation*
TLDR
Biochemical and mutational analyses revealed that Prx3 reduces H2O2, utilizing glutaredoxin 3 (Grx3) and glutathione (GSH) as reductants, and requires only N-terminal peroxidatic cysteine for its catalysis, and suggested that prx3 is a Grx3/GSH-dependent 1-Cys Prx and oxidized without forming intermolecular disulfide bonds.
Peroxide-Sensing Transcriptional Regulators in Bacteria
ABSTRACT The ability to maintain intracellular concentrations of toxic reactive oxygen species (ROS) within safe limits is essential for all aerobic life forms. In bacteria, as well as other
The Major Catalase Gene (katA) of Pseudomonas aeruginosa PA14 Is under both Positive and Negative Control of the Global Transactivator OxyR in Response to Hydrogen Peroxide
TLDR
The results suggest that P. aeruginosa OxyR is a bona fide transcriptional regulator of the katA gene, sensing H( 2)O(2) based on the conserved Cys residues, involving more than one oxidation as well as activation state in vivo.
Activation of the OxyR transcription factor by reversible disulfide bond formation.
The OxyR transcription factor is sensitive to oxidation and activates the expression of antioxidant genes in response to hydrogen peroxide in Escherichia coli. Genetic and biochemical studies
Distinct Characteristics of Two 2-Cys Peroxiredoxins of Vibrio vulnificus Suggesting Differential Roles in Detoxifying Oxidative Stress*
TLDR
It is revealed that the two Prxs are differentially optimized for detoxifying distinct ranges of H2O2, and proposed that Prx2 is a residential scavengers of peroxides endogenously generated, whereas Prx1 is an occasional scavenger of per oxides exogenously encountered.
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