Managing oxidative stresses in Shewanella oneidensis: intertwined roles of the OxyR and OhrR regulons. (11th March 2014)

• Record Type: Journal Article
• Authors: Li, Ning; Luo, Qixia; Jiang, Yaoming; Wu, Genfu; Gao, Haichun
• Is Part Of: Environmental microbiology. Volume 16:Number 6(2014:Jun.)
• Page Start: 1821
• Page End: 1834
• Publication Date: 2014-03-11
• Subjects: Microbial ecology -- Periodicals; Environmental Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1462-2920.12418
• Languages: English
• ISSNs: 1462-2912

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p> <italic>S</italic> <italic>hewanella oneidensis</italic>, renowned for its remarkable respiratory abilities, inhabit redox‐stratified environments prone to reactive oxygen species (ROS) formation. Two major oxidative stress regulators, analogues of OxyR and OhrR, specifically respond to H<sub>2</sub>O<sub>2</sub> and organic peroxides (OP), respectively, are encoded in the genome based on sequence comparison to well‐studied models. Presumably, these analogues provide protection from ROS. An understanding of <italic>S</italic><italic>. oneidensis</italic> OxyR has been established recently, which functions as both repressor and activator to mediate H<sub>2</sub>O<sub>2</sub>‐induced oxidative stress. Here, we report the first study of elucidating molecular mechanisms underlying the <italic>S</italic><italic>. oneidensis</italic> response to OP‐induced oxidative stress. We show that <italic>S</italic><italic>. oneidensis</italic> has OhrR, an OP stress regulator with two novel features. The sensing and responding residues of OhrR are not equally important for regulation and the regulator directly controls transcription of the <italic>SO</italic><italic>1563</italic> gene, in addition to the <italic>ohr</italic> gene which encodes the major OP scavenging protein. Importantly, we present evidence suggesting that the OxyR and OhrR regulons of <italic>S</italic><italic>. oneidensis</italic> appear to be functionally intertwined as both OxyR and OhrR systems can sense and response to H<sub>2</sub>O<sub>2</sub> and OP agents.</p> </abstract>