Search results for "Response regulator"
showing 10 items of 25 documents
Alternative respiratory pathways of Escherichia coli: energetics and transcriptional regulation in response to electron acceptors
1997
AbstractThe electron-transport chains of Escherichia coli are composed of many different dehydrogenases and terminal reductases (or oxidases) which are linked by quinones (ubiquinone, menaquinone and demethylmenaquinone). Quinol:cytochrome c oxido-reductase (`bc1 complex') is not present. For various electron acceptors (O2, nitrate) and donors (formate, H2, NADH, glycerol-3-P) isoenzymes are present. The enzymes show great variability in membrane topology and energy conservation. Energy is conserved by conformational proton pumps, or by arrangement of substrate sites on opposite sides of the membrane resulting in charge separation. Depending on the enzymes and isoenzymes used, the H+/e− rat…
The Agr communication system provides a benefit to the populations of Listeria monocytogenes in soil
2014
International audience; In this study, we investigated whether the Agr communication system of the pathogenic bacterium Listeria monocytogenes was involved in adaptation and competitiveness in soil. Alteration of the ability to communicate, either by deletion of the gene coding the response regulator AgrA (response-negative mutant) or the signal pro-peptide AgrD (signal-negative mutant), did not affect population dynamics in soil that had been sterilized but survival was altered in biotic soil suggesting that the Agr system of L. monocytogenes was involved to face the complex soil biotic environment. This was confirmed by a set of co-incubation experiments. The fitness of the response-negat…
Requirement of the Lactobacillus casei MaeKR two-component system for L-malic acid utilization via a malic enzyme pathway.
2009
ABSTRACTLactobacillus caseican metabolizel-malic acid via malolactic enzyme (malolactic fermentation [MLF]) or malic enzyme (ME). Whereas utilization ofl-malic acid via MLF does not support growth, the ME pathway enablesL. caseito grow onl-malic acid. In this work, we have identified in the genomes ofL. caseistrains BL23 and ATCC 334 a cluster consisting of two diverging operons,maePEandmaeKR, encoding a putative malate transporter (maeP), an ME (maeE), and a two-component (TC) system belonging to the citrate family (maeKandmaeR). Homologous clusters were identified inEnterococcus faecalis,Streptococcus agalactiae,Streptococcus pyogenes, andStreptococcus uberis. Our results show that ME is …
Phosphorylation and DNA binding of the regulator DcuR of the fumarate-responsive two-component system DcuSR of Escherichia coli
2004
The function of the response regulator DcuR of the DcuSR fumarate two-component sensory system of Escherichia coli was analysed in vitro. Isolated DcuR protein was phosphorylated by the sensory histidine kinase, DcuS, and ATP, or by acetyl phosphate. In gel retardation assays with target promoters (frdA, dcuB, dctA), phosphoryl DcuR (DcuR-P) formed a high-affinity complex, with an apparent K D (app. K D) of 0·2–0·3 μM DcuR-P, and a low-affinity (app. K D 0·8–2 μM) complex. The high-affinity complex was formed only with promoters transcriptionally-regulated by DcuSR, whereas low-affinity binding was seen also with some DcuSR-independent promoters. The binding site of DcuR-P at the dcuB promo…
The sensor kinase DcuS of Escherichia coli: two stimulus input sites and a merged signal pathway in the DctA/DcuS sensor unit
2012
Abstract The membrane-integral sensor kinase DcuS of Escherichia coli consists of a periplasmically located sensory PASP domain, transmembrane helices TM1 and TM2, a cytoplasmic PASC domain and the kinase domain. Stimulus (C4-dicarboxylate) binding at PASP is required to stimulate phosphorylation of the kinase domain, resulting in phosphoryl transfer to the response regulator DcuR. PASC functions as a signaling device or a relay in signal transfer from TM2 to the kinase. Phosphorylated DcuR induces the expression of the target genes. Sensing by DcuS requires the presence of the C4-dicarboxylate transporter DctA during aerobic growth. DctA forms a sensor unit with DcuS, and a short C-termina…
Oligomeric Sensor Kinase DcuS in the Membrane of Escherichia coli and in Proteoliposomes: Chemical Cross-linking and FRET Spectroscopy
2010
The DcuSR (dicarboxylate uptake sensor and regulator) system of Escherichia coli is a typical two-component system consisting of a membranous sensor kinase (DcuS) and a cytoplasmic response regulator (DcuR) (11, 26, 48). DcuS responds to C4-dicarboxylates like fumarate, malate, or succinate (19). In the presence of the C4-dicarboxlates, the expression of the genes of anaerobic fumarate respiration (dcuB, fumB, and frdABCD) and of aerobic C4-dicarboxylate uptake (dctA) is activated. DcuS is a histidine protein kinase composed of two transmembrane helices with an intermittent sensory PAS domain in the periplasm (PASP) that was also termed the PDC domain (for PhoQ/DcuS/DctB/CitA domain or fold…
Phosphate-controlled regulator for the biosynthesis of the dalbavancin precursor A40926
2007
ABSTRACT The actinomycete Nonomuraea sp. strain ATCC 39727 produces the glycopeptide A40926, the precursor of the novel antibiotic dalbavancin. Previous studies have shown that phosphate limitation results in enhanced A40926 production. The A40926 biosynthetic gene ( dbv ) cluster, which consists of 37 genes, encodes two putative regulators, Dbv3 and Dbv4, as well as the response regulator (Dbv6) and the sensor-kinase (Dbv22) of a putative two-component system. Reverse transcription-PCR (RT-PCR) and real-time RT-PCR analysis revealed that the dbv14 - dbv8 and the dbv30 - dbv35 operons, as well as dbv4 , were negatively influenced by phosphate. Dbv4 shows a putative helix-turn-helix DNA-bind…
High osmolarity glycerol (HOG) signalling in Magnaporthe oryzae: Identification of MoYPD1 and its role in osmoregulation, fungicide action, and patho…
2015
AbstractThis study comprises a first functional analysis of an YPD1-homologue in filamentous phytopathogenic fungi and its role in the HOG signalling pathway. We generated a gene deletion mutant of the gene MoYPD1 in Magnaporthe oryzae and characterized the resulting mutant strain. We have shown that MoYpd1p is a component of the phosphorelay system acting in the HOG pathway due to its Y2H protein interaction with the HKs MoHik1p and MoSln1p as well as with the response regulator MoSsk1p. Fungicidal activity of fludioxonil was reported to be based on the inhibition of MoHik1p resulting in hyperactivation of the HOG signalling pathway and lethality. Western analysis proved that both, osmotic…
Evolutionary history of the OmpR/IIIA family of signal transduction two component systems in Lactobacillaceae and Leuconostocaceae
2011
15 pages, 3 tables, 7 figures.
Fumarate regulation of gene expression in Escherichia coli by the DcuSR (dcuSR genes) two-component regulatory system.
1998
ABSTRACT In Escherichia coli the genes encoding the anaerobic fumarate respiratory system are transcriptionally regulated by C 4 -dicarboxylates. The regulation is effected by a two-component regulatory system, DcuSR, consisting of a sensory histidine kinase (DcuS) and a response regulator (DcuR). DcuS and DcuR are encoded by the dcuSR genes (previously yjdHG ) at 93.7 min on the calculated E. coli map. Inactivation of the dcuR and dcuS genes caused the loss of C 4 -dicarboxylate-stimulated synthesis of fumarate reductase ( frdABCD genes) and of the anaerobic fumarate-succinate antiporter DcuB ( dcuB gene). DcuS is predicted to contain a large periplasmic domain as the supposed site for C 4…