AUTHOR=Wan Fen , Feng Xue , Yin Jianhua , Gao Haichun 

TITLE=Distinct H2O2-Scavenging System in Yersinia pseudotuberculosis: KatG and AhpC Act Together to Scavenge Endogenous Hydrogen Peroxide

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.626874

DOI=10.3389/fmicb.2021.626874

ISSN=1664-302X

ABSTRACT=<p>To colonize in the digestive tract of animals and humans, <italic>Yersinia pseudotuberculosis</italic> has to deal with reactive oxygen species (ROS) produced by host cells and microbiota. However, an understanding of the ROS-scavenging systems and their regulation in this bacterium remains largely elusive. In this study, we identified OxyR as the master transcriptional regulator mediating cellular responses to hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) in <italic>Y. pseudotuberculosis</italic> through genomics and transcriptomics analyses. OxyR activates transcription of diverse genes, especially the core members of its regulon, including those encoding catalases, peroxidases, and thiol reductases. The data also suggest that sulfur species and manganese may play a particular role in the oxidative stress response of <italic>Y. pseudotuberculosis</italic>. Among the three H<sub>2</sub>O<sub>2</sub>-scavenging systems in <italic>Y. pseudotuberculosis</italic>, catalase/peroxidase KatE functions as the primary scavenger for high levels of H<sub>2</sub>O<sub>2</sub>; NADH peroxidase <italic>a</italic>lkyl <italic>h</italic>ydro<italic>p</italic>eroxide <italic>r</italic>eductase (AhpR) and catalase KatG together are responsible for removing low levels of H<sub>2</sub>O<sub>2</sub>. The simultaneous loss of both AhpC (the peroxidatic component of AhpR) and KatG results in activation of OxyR. Moreover, we found that AhpC, unlike its well-characterized <italic>Escherichia coli</italic> counterpart, has little effect on protecting cells against toxicity of organic peroxides. These findings provide not only novel insights into the structural and functional diversity of bacterial H<sub>2</sub>O<sub>2</sub>-scavenging systems but also a basic understanding of how <italic>Y. pseudotuberculosis</italic> copes with oxidative stress.</p>