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Showing 1 to 20 of 31 for “"LuxR"”.
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Transcriptional Control during Quorum Sensing by LuxR and LuxR Homologues
… is recognized and bound by the activator protein LuxR. LuxR subsequently binds to the lux box centered at à 42.5 bp upstream of the transcription initiation site and activates transcription from the lux operon promoter, resulting in the emission of light at high cell densities. LuxR consists of …
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Engineering LuxR-type quorum sensing proteins for new functions
… diffusion rate and expression profile of a given LuxR-family module are not modular. Here, we develop chimeric proteins that can accept the small molecule cognate belonging to the las operon from Pseudomonas aeruginosa while activating the cognate promoter of other quorum sensing systems. The …
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Analysis of the Regulons Controlled by Transcriptional Regulators LuxR and LitR in Vibrio fischeri
… MJ-100 whose expression was dependent on LuxR and 3-oxo-hexanoyl-L-homoserine lactone (3-oxo-C6-HSL). A lacZ reporter was used to show that the promoters for qsrP, acfA, and ribB were directly activated via LuxR-3-oxo-C6-HSL in recombinant Escherichia coli. The sites of transcription …
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The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit
… C8-HSL) and the transcriptional activator LuxR regulate the luminescence system in a cell-density dependent manner by a process termed quorum sensing. In this study, five additional proteins whose production is regulated by quorum sensing are described, and the genes encoding four of the …
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The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinduce/LuxR regulatory circuit
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Biology, 1999.
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Amino Acid Residues in LuxR Critical for its Mechanism of Transcriptional Activation during Quorum Sensing
… the N-terminal domain of a regulatory protein, LuxR. In response to autoinducer binding, LuxR is believed to undergo a conformational change that allows the C-terminal domain to activate transcription of the luminescence or <I>lux</I> operon. To further understand the mechanism of LuxR-dependent …
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The Functional Characterization of QSEC a Bacterial Adrenergic Receptor and the LuxR Homologue SDIA in EHEC
… of EHEC. We have shown that mutation of the LuxR homologue SdiA, decreases EHEC’s ability to colonize the bovine intestine. The LuxR proteins are transcription factors that are activated or repressed by the quorum sensing molecules, autoinducer-1 (AI-1) which are N-acyl homoserine lactones …
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Multi-tiered Regulation of luxR Provides Precise Timing and Maintenance of the Quorum Sensing Response of Vibrio fischeri
… A key regulator of this system is LuxR, which is the transcriptional activator of the lux operon as well as several other genes in. LuxR also autoregulates its own transcription, which we have shown causes bistability and hysteresis in the quorum-sensing response. This behavior …
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The Influence of Changes In theMolecular Structure of N-Acylhomoserine Lactones On the Complexation and Dna-Binding of Luxr Protein
… range of Gram-negative Proteobacteria possess LuxR-type transcriptional regulatory proteins which can perceive and bind cognate autoinducer N-acylhomoserine lactones (AHLs), thereby inducing a conformational change and subsequently binding to lux box-like target genes to regulate transcription. …
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Role of the C-terminal domain of the <font face = "symbol">a</font> subunit of RNA polymerase in transcriptional activation of the <i>lux</i> operon during quorum sensing
… a cell density-dependent manner by the activator LuxR in the presence of an acylated homoserine lactone autoinducer molecule (3-oxo-hexanoyl homoserine lactone). LuxR, which binds to the <i>lux</i> operon promoter at position -42.5, is thought to function as an ambidextrous activator making …
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Role of region 4 of the sigma 70 subunit of RNA polymerase in transcriptional activation of the lux operon during quorum sensing
… autoinducer-dependent transcriptional activator LuxR. LuxR, a 250 amino acid polypeptide, binds to a site known as the lux box centered at position -42.5 relative to the luxI transcriptional start site. During transcriptional activation of the lux operon, LuxR is thought to function as an …
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Structure-Function Analysis of the EsaR N-terminal Domain
The LuxR protein family is a class of quorum-sensing regulated bacterial transcription factors that alter gene expression as a function of ligand detection. This coincides with a high population density and/or a low rate of signal ligand diffusion. The majority of LuxR proteins are activated only …
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Development of Methods for Structural Characterization of Pantoea stewartii Quorum-Sensing Regulator EsaR
The LuxR family of proteins serves as quorum-sensing transcriptional regulators in proteobacteria. At high population densities, a small acyl-homoserine lactone (AHL) molecule, produced by a LuxI homologue, accumulates in the environment. The LuxR proteins bind to their respective AHL when the …
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Structure/Function Analysis of the Quorum-sensing Regulator EsaR from the Plant Pathogen Pantoea stewartii
… to the process of quorum sensing, the LuxI and LuxR homologues EsaI and EsaR. Most LuxR homologues function as activators of transcription in the presence of their cognate acylated homoserine lactone signal (AHL). EsaR utilizes an AHL-response opposite of the majority of the LuxR homologues. …
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Structural and Mechanistic Roles of Novel Chemical Ligands on Quorum Sensing Transcription Regulator SdiA in Enterohemorrhagic Escherichia coli
… unclear. Most Gram-negative bacteria use the LuxR family of transcription factors to regulate gene expression to coordinate population behavior by sensing endogenously produced chemical signaling molecules, acyl-homoserine lactones (AHLs) [1]. However, some bacteria such as Escherichia coli …
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Regulatory Control of Brucella Genetic Transcription
… sensing system. Major findings include that the LuxR protein BabR contributes to Brucella survival, that 3-OXO-C12 is likely physiologically relevant to the bacterium, and that the quorum sensing system regulates denitrification. Chapter 3 describes a new method for identifying transcription …
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Phenotypic and transcriptional analysis of secondary metabolites production in Pseudomonas corrugata CFBP5454
… che codificano per i regolatori trascrizionali LuxR, P. corrugata GL2 (pcoR-) e GLRFIA (rfiA-), in cui la produzione di lipopeptidi ciclici (CLP) risulta alterata, hanno mostrato un'attività antimicrobica ridotta, a seconda del ceppo batterico, patogeno e substrato, ma indicano chiaramente la …
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Experimental Methods in Support of the Development of a Computational Model for Quorum Sensing in Vibrio fischeri
… in two divergent transcriptional units: luxR and luxICDABEG. The latter contains the genes required for luminescence and the luxI gene necessary for synthesis of an N-acyl-homoserine lactone commonly called autoinducer (AI). The luxR gene codes for a transcriptional regulatory protein …
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Investigation of the quorum-sensing regulon in the corn pathogen Pantoea stewartii
… of capsule production. EsaR is a member of the LuxR family of QS-dependent transcriptional factors. Most LuxR homologs are unstable and/or insoluble in the absence of AHL which has hindered structural studies. Chapter Two describes the changes in the structure of EsaR due to binding of AHL …
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Identification of Quorum Sensing Genes in Halococcus Hamelinensis SP. Nov. 100Na1
… for transcriptional regulator could be a luxR homolog since LuxR protein is a transcriptional regulator. Future experiments will determine the actual luxI homologs, the structure of the signal, and the genetic regulation of this genetic system.</p>
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