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Showing 1 to 20 of 37 for “"autoinducer"”.
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The synthesis and biological evaluation of a library of autoinducer-antibiotic conjugates
… using a similar approach, but using bacterial autoinducers instead of siderophores. Autoinducers are required for coordination of bacterial behaviours and are involved in the control of swarming, virulence factor production and biofilm formation. The quorum sensing molecules produced by …
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Autoinducer-2-based quorum sensing of foodborne pathogenic bacteria under food related conditions
… studies was to evaluate potential involvement of autoinducer (AI)-2-based quorum sensing (quorum sensing: cell density dependent cell-to-cell signaling) of foodborne pathogenic bacteria in food environments. Under the conditions of these studies, AI-2 activity of Salmonella and Escherichia coli …
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The quorum-sensing regulation of Vibrio fischeri : novel components of the autoinducer/LuxR regulatory circuit
… low population density by C8-HSL. Probable LuxR/autoinducer binding sites are found in the promoter region of each. QsrP and RibB are encoded monocistronically, whereas AcfA and QsrV appear to be encoded by a two-gene operon. On the basis of sequence similarity to proteins of known function from …
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Mutant analysis of luminescence and autoinduction in a marine bacterium
… is mediated by a signal molecule called the "autoinducer". The mechanistic bases of both luminescence and autoinduction are well known in V. fischeri, but this knowledge is mostly derived from studies of the cloned luminescence and autoinduction genes expressed in Escherichia coli. In this …
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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
… relies on the formation of a complex between the autoinducer molecule, N-(3-oxohexanoyl) homoserine lactone, and the 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 …
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Structural and functional elucidation of four putative PQS-binding proteins in Pseudomonas aeruginosa
… *rhl*, and *pqs* systems rely on a receptor-autoinducer relationship: these receptor-autoinducer complexes are LasR-OdDHL, RhlR-BHL, and PqsR-PQS, respectively. When the receptors (LasR, RhlR, PqsR) bind with their cognate autoinducer (OdDHL, BHL, PQS, respectively), they act as transcription …
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Amino Acid Residues in LuxR Critical for its Mechanism of Transcriptional Activation during Quorum Sensing
… an acylated homoserine chemical signal (autoinducer) is synthesized by the bacteria and used to sense their own species in a given environment. As the autoinducer levels rise, complexes form between the autoinducer and the N-terminal domain of a regulatory protein, LuxR. In response to …
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Mathematical Models of Quorum Sensing
… communication are mediated by molecules called autoinducers that are both synthesized and collected by quorum sensing bacteria. We employ differential equations to investigate and understand the dynamics of underlying signaling processes. The first two models of this study were constructed with …
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Biochemical Assay Optimization and Computational Screening Efforts to Identify Potential LuxS Inhibitors
… QS is regulated by the small signaling molecule autoinducer-2 (AI-2) and is implicated in the infectious behaviors of various bacterial species. AI-2 is biosynthesized from <em>S-</em>ribosylhomocysteine (SRH) by the enzyme LuxS and induces interspecies cell-to-cell communication. Inhibition of …
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The Influence of Changes In theMolecular Structure of N-Acylhomoserine Lactones On the Complexation and Dna-Binding of Luxr Protein
… to surrounding chemical signals known as autoinducers. A wide 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 …
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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
… 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 multiple contacts with RNA polymerase (RNAP). The specific …
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Intercellular communication in uropathogenic Escherichia coli and the probiotic Lactobacillus reuter
… This study sought to characterize the role of autoinducer 2 (AI-2) in the regulation of virulence factors of uropathogenic Escherichia coli J96, determine if the probiotic Lactobacillus reuteri RC-14 produced AI-2, and evaluate if secreted products from the probiotic could affect pathogen …
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Survival and recovery of Escherichia coli O157:H7 during starvation at sub-optimal temperatures
… on agar. The role of quorum sensing (LuxS/autoinducer-2) on starved cell recovery was investigated by supplementing PCA with quorum sensing molecules and using a mutant strain deficient in luxS, a gene encoding the synthase of autoinducer-2. The ability of starved and non-starved cells to …
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Synthesis of S-Ribosyl-L-homocysteine and Analogs Modified at the Homocysteine-C3 Position
… (DPD), which is the precursor of autoinducer-2 (AI-2). Thus, inhibitors of LuxS could prevent QS by halting the conversion of SRH to AI-2 rendering the cell “uncommunicative”. This work shows the successful chemical synthesis of SRH and progress towards the synthesis of SRH analogs …
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HAEMOPHILUS INFLUENZAE AND MORAXELLA CATARRHALIS INTRA- AND INTERSPECIES QUORUM SIGNALING
… is bacterial communication via quorum signaling. Autoinducer-2 (AI-2) is termed an interspecies signal as the genetic determinant for AI-2 production (<italic>luxS</italic>) is highly conserved and many species possess the machinery to respond to AI-2. <italic>H. influenzae</italic> has a …
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Mikrobielle Ökologie N-Acyl-L-Homoserinlacton-produzierender Bakterien in der Rhizosphäre von Tomatenpflanzen
… work characterised the microbial ecology of the autoinducer (AHL) producing bacteria Serratia liquefaciens MG1 and Pseudomonas putida IsoF in the rhizosphere of tomato plants. Gfp- and rfp-tagged strains of the AHL producing wiltypes S. liquefaciens MG1 and P. putida IsoF were compared with its …
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The Functional Characterization of QSEC a Bacterial Adrenergic Receptor and the LuxR Homologue SDIA in EHEC
… receptor which responds to the bacterial signal autoinducer-3 (AI-3) and the host signals epinephrine and norepinephrine. EHEC senses these signals in the gut in order to coordinate expression of multiple virulence factors. These factors include the locus of enterocyte effacement (LEE) genes …
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Biochemical Evaluation of SRH Analogs as Potential LuxS Inhibitors
… facilitated by small molecules called autoinducers. Interspecies quorum sensing is facilitated by the autoinducer AI-2. The enzyme LuxS catalyzes the formation of AI-2 from <em>S</em>-ribosyl homocysteine (SRH) in a wide variety of bacterial species. Inhibition of LuxS would therefore …
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New Sensing Modalities for Bacterial and Environmental Phenomena
… molecules: the universal quorum sensing molecule autoinducer-2 (AI-2), the species-specific Pseudomonas Quinolone Signal (PQS), and the stationary phase indicator molecule indole. SERS substrates were formed by galvanic displacement, a substrate fabrication method that can be adapted to many SERS …
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Chemical Processes That Govern the Natural Attenuation of Microbial Signals: Environments That Simulate Photosynthetic Biofilms
… (DPD) derivatives functionally classified as autoinducer-2 (AI2). Oxidative attenuation of the acylhomoserine lactones (AHLs) by hydroxyl radicals results in the formation of keto- and hydroxo AHLs, some of which are more potent signals (per mole) than the original AHLs. In contrast, parallel …
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