A Novel OxyR Sensor and Regulator of Hydrogen Peroxide Stress with One Cysteine Residue in Deinococcus radiodurans

In bacteria, OxyR is a peroxide sensor and transcription regulator, which can sense the presence of reactive oxygen species and induce antioxidant system. When the cells are exposed to H2O2, OxyR protein is activated via the formation of a disulfide bond between the two conserved cysteine residues (C199 and C208). 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 only 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). Because OxyR regulates Mn and Fe ion transporter genes, Mn/Fe ion ratio is changed in dr0615 mutant, suggesting that the genes involved in Mn/Fe ion homeostasis, and the genes involved in antioxidant mechanism are highly cooperative under extremely oxidant stress. In conclusion, these findings expand the OxyR family, which could be divided into two classes: typical 2-Cys OxyR and 1-Cys OxyR

Comparative analyses imply that the enigmatic sigma factor 54 is a central controller of the bacterial exterior

Contains fulltext : 95738.pdf (publisher's version ) (Open Access)BACKGROUND: Sigma-54 is a central regulator in many pathogenic bacteria and has been linked to a multitude of cellular processes like nitrogen assimilation and important functional traits such as motility, virulence, and biofilm formation. Until now it has remained obscure whether these phenomena and the control by Sigma-54 share an underlying theme. RESULTS: We have uncovered the commonality by performing a range of comparative genome analyses. A) The presence of Sigma-54 and its associated activators was determined for all sequenced prokaryotes. We observed a phylum-dependent distribution that is suggestive of an evolutionary relationship between Sigma-54 and lipopolysaccharide and flagellar biosynthesis. B) All Sigma-54 activators were identified and annotated. The relation with phosphotransfer-mediated signaling (TCS and PTS) and the transport and assimilation of carboxylates and nitrogen containing metabolites was substantiated. C) The function annotations, that were represented within the genomic context of all genes encoding Sigma-54, its activators and its promoters, were analyzed for intra-phylum representation and inter-phylum conservation. Promoters were localized using a straightforward scoring strategy that was formulated to identify similar motifs. We found clear highly-represented and conserved genetic associations with genes that concern the transport and biosynthesis of the metabolic intermediates of exopolysaccharides, flagella, lipids, lipopolysaccharides, lipoproteins and peptidoglycan. CONCLUSION: Our analyses directly implicate Sigma-54 as a central player in the control over the processes that involve the physical interaction of an organism with its environment like in the colonization of a host (virulence) or the formation of biofilm

Abstract book of the 26. dvs Hochschultag from 20.-22.09.2023

Czyrnick-Leber U, Kuhrs K, Kraft C, Wicker P, Gröben B. Der Effekt eines tänzerischen Kampfkunsttrainings auf die Konzentrationsfähigkeit von Strafgefangenen. In: Schlesinger T, Grimminger-Seidensticker E, Ferrauti A, et al., eds. Leistung steuern. Gesundheit stärken. Entwicklung fördern. . Bochum; 2023: 44

MONITORING AND CONTROL OF BIOTECHNOLOGICAL PRODUCTION PROCESSES BY BIO-FET-FIA-SENSORS

Single and multisensor Field Effect Transistors FET with a pH-sensitive Si/SiO2/SizN4/TazOs-gate and reference electrode (for single semsor) were developed and used for manufacturing the following BIO-FETs: for glucose analysis: Glucose Oxidase-FETs (GOD-FET), for penicillin G and V analysis: Penicillin G Amidase- and Penicillinase-FETs, for urea analysis: Urease-FET, and for cephalosporin C analysis: Cephalosporinase-FET. The GOD-FETswereintegrated into the FIA-system of Eppendorf (EVA) and used for monitoring the glucose concentration in microbial cultivation and production processes with recombinant_Escherichia coli K12 MF, recombinant Escherichia coli JM103, Saccharomyces cerevisiae H620, and Candida boidinii. Urease-FET-FIA was used to monitor the urea concentration in a simulatedcultivation of Cephalosporium acremonium and UREASE-FET-FIA and GOD-FET-FIA for the monitoring of urea and glucose concentrations in simulated Saccharomyces cerevisiae cultivations