0000000000394719

AUTHOR

Daniela Lehnen

showing 3 related works from this author

Regulation of type 1 fimbriae synthesis and biofilm formation by the transcriptional regulator LrhA of Escherichia coli

2005

Type 1 fimbriae ofEscherichia colifacilitate attachment to the host mucosa and promote biofilm formation on abiotic surfaces. The transcriptional regulator LrhA, which is known as a repressor of flagellar, motility and chemotaxis genes, regulates biofilm formation and expression of type 1 fimbriae. Whole-genome expression profiling revealed that inactivation oflrhAresults in an increased expression of structural components of type 1 fimbriae.In vitro, LrhA bound to the promoter regions of the twofimrecombinases (FimB and FimE) that catalyse the inversion of thefimApromoter, and to the invertible element itself. TranslationallacZfusions with these genes and quantification offimEtranscript le…

urinary-tractphase variationFimbrialac operonRepressorsuicide vectorBiologyFlagellummedicine.disease_causeMicrobiologyBacterial AdhesionMicrobiologylysr homologMiceglobal regulatorh-nsEscherichia colimedicineAnimalsHumansgenetic-analysisPromoter Regions GeneticEscherichia coliEscherichia coli InfectionsOligonucleotide Array Sequence AnalysisPhase variationRegulation of gene expressionfim switchEscherichia coli ProteinsGene Expression ProfilingBiofilmGene Expression Regulation Bacterialbiochemical phenomena metabolism and nutritionintegration host factorBiofilmsFimbriae BacterialMutationUrinary Tract Infectionsvirulence determinantsTranscription Factors
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LrhA as a new transcriptional key regulator of flagella, motility and chemotaxis genes in Escherichia coli

2002

The function of the LysR-type regulator LrhA of Escherichia coli was defined by comparing whole-genome mRNA profiles from wild-type E. coli and an isogenic lrhA mutant on a DNA microarray. In the lrhA mutant, a large number (48) of genes involved in flagellation, motility and chemotaxis showed relative mRNA abundances increased by factors between 3 and 80. When a representative set of five flagellar, motility and chemotaxis genes was tested in lacZ reporter gene fusions, similar factors for derepression were found in the lrhA mutant. In gel retardation experiments, the LrhA protein bound specifically to flhD and lrhA promoter DNA (apparent K-D approximate to 20 nM), whereas the promoters of…

DNA BacterialbindingTranscription GeneticRecombinant Fusion ProteinsMolecular Sequence DataMutantacetyl phosphatelac operonBiologymedicine.disease_causeMicrobiologyh-ns proteink-12lysr homologBacterial ProteinsGenes ReporterTranscription (biology)expressionEscherichia colimedicinernaRNA MessengerPromoter Regions GeneticMolecular BiologyGeneEscherichia coliDerepressionOligonucleotide Array Sequence AnalysisBase SequenceChemotaxisEscherichia coli ProteinsGene Expression ProfilingPromoterChemotaxisGene Expression Regulation BacterialMolecular biologyco2 fixationmaster operonDNA-Binding ProteinsRNA BacterialLac OperonFlagellaTrans-ActivatorssignalTranscription Factors
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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…

DNA BacterialTranscription GeneticMolecular Sequence DataBiologymedicine.disease_causeMicrobiologychemistry.chemical_compoundFumaratesEscherichia colimedicinePhosphorylationBinding sitePromoter Regions GeneticEscherichia coliBinding SitesBase SequenceEscherichia coli ProteinsHistidine kinasePromoterGene Expression Regulation BacterialMolecular biologyTwo-component regulatory systemDNA-Binding ProteinsResponse regulatorchemistryBiochemistryPhosphorylationProtein KinasesDNASignal TransductionTranscription FactorsMicrobiology
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