Project description:In Deinococcus radiodurans, a previously unreported special characteristic of DrOxyR (DR0615) is found with only one conserved cysteine. dr0615 gene mutant is hypersensitive to H2O2, but a little to ionizing radiation. Site-directed mutagenesis and subsequent in vivo functional analyses revealed that the conserved cysteine (C210) is necessary for sensing H2O2, but its mutation did not alter the binding characteristics of OxyR on DNA. Under oxidant stress, DrOxyR is oxidized to sulfenic acid form, which can be reduced by reducing reagents. In addition, quantitative real-time PCR and global transcription profile results showed that OxyR is not only a transcriptional activator (e.g., katE, drb0125), but also a transcriptional repressor (e.g., dps, mntH). Transcriptional profiling of comparing wildtype strains with oxyR disruption strains under normal growth conditions. Keywords: Genetic modification
Project description:This study explores the regulatory network of a sRNA named PprS (previously Dsr2) in Deinococcus radiodurans R1. We compared the transcriptomes of two strains with and without exposure to 10 kGy acute ionizing radiation (IR): D. radiodurans R1 (wild-type) and a PprS knockdown mutant (PprSKD) that expresses ~2-fold less PprS compared to WT levels. Analysis of this RNAseq dataset demonstrated significant differential expression of several transcripts in both WT (34) and PprSKD (61) strains during recovery from IR. However, we did not observe any significantly differentially expressed transcripts between the two strains during recovery from IR. 31 transcripts were signficantly differentially expressed when comparing the two strains under unirradiated conditions. To determine the regulatory network that this sRNA, PprS could regulate we performed a MAPS (MS2-affinity purification followed by RNAsequencing) experiment in which a MS2-binding domain tagged PprS was expressed from a constutive promoter from a plasmid (pRADgro) in D. radiodurans R1. A control plasmid (containing only the MS2-binding domain) was also expressed and differential enrichment was compared to this control. MAPS suggested ~130 potential interacting transcripts with PprS and we were able to validate the binding and stabilization of one specific transcript, pprM, for PprS.
