title: PprM, a Cold Shock Domain-Containing Protein fromDeinococcus radiodurans, Confers Oxidative Stress Tolerance toEscherichia coli.
abstract: Escherichia coliis a representative microorganism that is frequently used for industrial biotechnology; thus its cellular robustness should be enhanced for the widespread application ofE. coliin biotechnology. Stress response genes from the extremely radioresistant bacteriumDeinococcus radioduranshave been used to enhance the stress tolerance ofE. coli. In the present study, we introduced the cold shock domain-containing protein PprM fromD. radioduransintoE. coliand observed that the tolerance to hydrogen peroxide (H2O2) was significantly increased in recombinant strains (Ec-PprM). The overexpression of PprM inE. colielevated the expression of some OxyR-dependent genes, which play important roles in oxidative stress tolerance. Particularly,mntH(manganese transporter) was activated by 9-fold in Ec-PprM, even in the absence of H2O2stress, which induced a more than 2-fold increase in the Mn/Fe ratio compared with wild type. The reduced production of highly reactive hydroxyl radicals (·OH) and low protein carbonylation levels (a marker of oxidative damage) in Ec-PprM indicate that the increase in the Mn/Fe ratio contributes to the protection of cells from H2O2stress. PprM also conferred H2O2tolerance toE. coliin the absence of OxyR. We confirmed that the H2O2tolerance ofoxyRmutants reflected the activation of theycgZ-ymgABCoperon, whose expression is activated by H2O2in an OxyR-independent manner. Thus, the results of the present study showed that PprM could be exploited to improve the robustness ofE. coli.
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Sun-Ha
authors.initials: SH
authors.lastname: Park
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Harinder
authors.initials: H
authors.lastname: Singh
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Deepti
authors.initials: D
authors.lastname: Appukuttan
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Sunwook
authors.initials: S
authors.lastname: Jeong
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Yong Jun
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Jung
authors.affiliation: Radiation Microbiology Laboratory, Department of Life Sciences, Faculty of Life Sciences, Toyo University Gunma, Japan.
authors.forename: Issay
authors.initials: I
authors.lastname: Narumi
authors.affiliation: Research Division for Biotechnology, Korea Atomic Energy Research Institute Jeongeup, South Korea.
authors.forename: Sangyong
authors.initials: S
authors.lastname: Lim
keywords: Deinococcus radiodurans; Escherichia coli; MntH (proton-dependent Mn transporter); PprM; oxidative stress tolerance; ycgA-ymgABC operon