Shift in Ribonucleotide Reductase Gene Expression in Pseudomonas aeruginosa during Infection

Sjöberg, Britt‐Marie; Torrents, Eduard

doi:10.1128/iai.01212-10

Cited by 34 publications

(75 citation statements)

References 31 publications

(39 reference statements)

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“…Several pathogens encode multiple RNRs of different classes and upregulate class III RNR, also known as NrdDs (“Nrd” for nucleotide reductase, “D” specifies class III RNR), to cope with oxygen limitation within biofilms (Cendra Mdel et al , 2012, Crespo et al , 2016). Knockouts of NrdDs in bacteria cause decreased virulence in animal infection models, suggesting that these enzymes enhance the ability of the bacteria to infect the host (Kirdis et al , 2007, Sjoberg and Torrents, 2011). …”

Section: Gre Ribonucleotide Reductasesmentioning

confidence: 99%

New tricks for the glycyl radical enzyme family

Backman

Funk

Dawson

et al. 2017

Critical Reviews in Biochemistry and Molecular Biology

129

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Glycyl radical enzymes (GREs) are important biological catalysts in both strict and facultative anaerobes, playing key roles both in the human microbiota and in the environment. GREs contain a backbone glycyl radical that is post-translationally installed, enabling radical-based mechanisms. GREs function in several metabolic pathways including mixed acid fermentation, ribonucleotide reduction, and the anaerobic breakdown of the nutrient choline and the pollutant toluene. By generating a substrate-based radical species within the active site, GREs enable C-C, C-O, and C-N bond breaking and formation steps that are otherwise challenging for non-radical enzymes. Identification of previously unknown family members from genomic data and the determination of structures of well-characterized GREs have expanded the scope of GRE-catalyzed reactions as well as defined key features that enable radical catalysis. Here we review the structures and mechanisms of characterized GREs, classifying members into five categories. We consider the open questions about each of the five GRE classes and evaluate the tools available to interrogate uncharacterized GREs.

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Section: Gre Ribonucleotide Reductasesmentioning

confidence: 99%

New tricks for the glycyl radical enzyme family

Backman

Funk

Dawson

et al. 2017

Critical Reviews in Biochemistry and Molecular Biology

129

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“…This method used the family of plasmids derived from pETS130-GFP (see Supporting Information Table S1), which encode transcriptional fusions of the promoters of all nrd operons with GFP. 42,45 To evaluate the expression of these operons under different oxygenation conditions, a full experiment was conducted for each desired oxygen concentration using strains containing each transcriptional fusion, as well as one with a promoterless GFP plasmid to evaluate the fluorescence level of a blank reaction.…”

Section: Gene Reporter Assay In a Controlled Atmospherementioning

confidence: 99%

“…39,41 On the other hand, P aeruginosa encodes class Ia, II, and III RNRs. 42 Class I RNR is constitutively expressed, as Anr/Dnr do not repress aerobic metabolism. 30 Class II and III RNRs are induced under reduced oxygen tension by Anr and Dnr.…”

Section: Introductionmentioning

confidence: 99%

Gradual adaptation of facultative anaerobic pathogens to microaerobic and anaerobic conditions

2019

Self Cite

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Many notable human pathogens are facultative anaerobes. These pathogens exhibit redundant metabolic pathways and a whole array of regulatory systems to adapt to changing oxygen levels. However, our knowledge of facultative anaerobic pathogens is mostly based on fully aerobic or anaerobic cultures, which does not reflect real infection conditions, while the microaerobic range remains understudied. Here, we examine the behavior of pathogenic and nonpathogenic strains of two facultative anaerobes, Escherichia coli and Pseudomonas aeruginosa, during the aerobicanaerobic transition. To do so, we introduce a new technique named AnaeroTrans, in which we allow self-consumption of oxygen by steady-state cultures and monitor the system by measuring the gas-phase oxygen concentration. We explore the different behavior of the studied species toward oxygen and examine how this behavior is associated with the targeted infection sites. As a model, we characterize the adaptation profile of the ribonucleotide reductase network, a complex oxygen-dependent enzymatic system responsible for the generation of the deoxyribonucleotides. We also explore the actions of the most important anaerobic regulators and how these regulators influence bacterial fitness. Our results allow us to classify the different elements that compose the aerobic-anaerobic transition into reproducible stages, thus showing the different adaptation mechanisms of the studied species. K E Y W O R D Sbiofilm, Escherichia, oxygen, Pseudomonas, ribonucleotide

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“…The proteins were electroblotted onto polyvinylidene difluoride (PVDF) membranes (Immun-Blot; Bio-Rad) using a semidry transfer system (BioRad), and the membranes were blocked overnight at 4°C in 5% skim milk in phosphate-buffered saline (PBS). The membranes were probed with a 1:10,000 dilution of rabbit anti-Pseudomonas aeruginosa NrdA (20). The detection of primary antibodies was performed using donkey anti-rabbit (Bio-Rad) horseradish peroxidase-conjugated secondary antibodies at a 1/50,000 dilution and visualized using the Amersham ECL Prime Western blotting reagent (GE Healthcare) according the manufacturer's protocol.…”

Section: Methodsmentioning

confidence: 99%

H-NS Is a Novel Transcriptional Modulator of the Ribonucleotide Reductase Genes in Escherichia coli

Cendra

Juárez

Madrid

et al. 2013

Journal of Bacteriology

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bRibonucleotide reductases (RNRs) are essential enzymes for DNA synthesis because they are responsible for the production of the four deoxyribonucleotides (dNTPs) from their corresponding ribonucleotides. Escherichia coli contains two classes of aerobic RNRs, encoded by the nrdAB (class Ia) and nrdHIEF (class Ib) operons, and a third RNR class, which is functional under anaerobic conditions and is encoded by the nrdDG (class III) operon. Because cellular imbalances in the amounts of the four dNTPs cause an increase in the rate of mutagenesis, the activity and the expression of RNRs must be tightly regulated during bacterial chromosome replication. The transcriptional regulation of these genes requires several transcription factors (including DnaA, IciA, FIS [factor for inversion stimulation], Fnr, Fur, and NrdR), depending on the RNR class; however, the factors that dictate the expression of some RNR genes in response to different environmental conditions are not known. We show that H-NS modulates the expression of the nrdAB and nrdDG operons. H-NS represses expression both in aerobically and in anaerobically growing cells. Under aerobic conditions, repression occurs at the exponential phase of growth as well as at the transition from the exponential to the stationary phase, a period when no dNTPs are needed. Under anoxic conditions, repression occurs mainly in exponentially growing cells. Electrophoretic mobility assays performed with two DNA fragments from the regulatory region of the nrdAB operon demonstrated the direct interaction of H-NS with these sequences.

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Shift in Ribonucleotide Reductase Gene Expression in Pseudomonas aeruginosa during Infection

Cited by 34 publications

References 31 publications

New tricks for the glycyl radical enzyme family

New tricks for the glycyl radical enzyme family

Gradual adaptation of facultative anaerobic pathogens to microaerobic and anaerobic conditions

H-NS Is a Novel Transcriptional Modulator of the Ribonucleotide Reductase Genes in Escherichia coli

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