title: Characterization of the role of the RadS/RadR two-component system in the radiation resistance of Deinococcus radiodurans.
abstract: Deinococcus radiodurans shows extraordinary tolerance to DNA damage, and exhibits differential gene expression and protein recycling. A putative response regulator, the DRB0091 (RadR) ORF, was identified from a pool of DNA-binding proteins induced in response to gamma radiation in this bacterium. radR is located upstream of drB0090, which encodes a putative sensor histidine kinase (RadS) on the megaplasmid. Deletion of these genes both individually and together resulted in hypersensitivity to DNA-damaging agents and a delayed or altered double-strand break repair. A ΔradRradS double mutant and a ΔradR single mutant showed nearly identical responses to gamma radiation and UVC. Wild-type RadR and RadS complemented the corresponding mutant strains, but also exhibited significant cross-complementation, albeit at lower doses of gamma radiation. The radS transcript was not detected in the ΔradR mutant, suggesting the existence of a radRS operon. Recombinant RadS was autophosphorylated and could catalyse the transfer of γ phosphate from ATP to RadR in vitro. These results indicated the functional interaction of RadS and RadR, and suggested a role for the RadS/RadR two-component system in the radiation resistance of this bacterium.
authors: Centre for Advanced Studies in Zoology, Department of Zoology, University of Pune, Pune 411007, India.|Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors: Shruti S
authors: SS
authors: Desai
authors: Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors: Yogendra S
authors: YS
authors: Rajpurohit
authors: Molecular Biology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
authors: Hari S
authors: HS
authors: Misra
authors: Centre for Advanced Studies in Zoology, Department of Zoology, University of Pune, Pune 411007, India.
authors: Dileep N
authors: DN
authors: Deobagkar
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D034301:Deinococcus / Q000201:enzymology / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D005720:Gamma Rays; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D009876:Operon; D018384:Oxidative Stress; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D011836:Radiation Tolerance; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D011494:Protein Kinases; D000071677:Histidine Kinase