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Showing 1 to 17 of 17 for “"TolC"”.
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Computational Study on MFP MexA in MexAB-OprM and RND transporter AcrB in AcrAB-TolC Efflux Pumps
… and E.coli / Salmonella, MexAB-OprM and AcrAB-TolC respectively. In particular, we studied the possible multimerization of the MFP component MexA and the effects of mutations in the AcrB distal binding pocket. The starting point for the first part of our study was the uncertainty about the …
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Structure and Dynamics of AcrA, a Periplasmic Component of a Multidrug Efflux Pump
… component of an efflux system AcrA-AcrB-TolC, which can expel different classes of antibiotics. AcrB is the inner membrane (IM) pump that utilizes proton-motive force for the active transport, TolC is the outer membrane (OM) channel, and AcrA coordinates the actions of AcrB and TolC, so …
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The role of AcrA in the antibiotic resistance and virulence of Salmonella enterica serovar Typhimurium
… component of the major efflux system AcrB-TolC of \(Salmonella\) Typhimurium. AcrA of S. \(Typhimurium\) SL1344 was inactivated and the mutant phenotype characterised. RT-PCR and western blotting were used to confirm expression of \(acrB/AcrB\) was retained in the acrA mutant. The AcrA …
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Structure & Function of Bacterial Transport Machines in their Cellular Context
… bacterial species are the MacA-MacB-TolC (MacAB-TolC) antibiotic efflux pump and the Type I Secretion System (T1SS), responsible respectively for antibiotic resistance and export of protein virulence factors. To pass the Gram-negative envelope in a one-step translocation process, both …
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Molecular recognition, in- and out- of equilibrium, in the actions of bacterial multidrug efflux nanomachines
… pumps present in bacterial lineages, the AcrAB-TolC assembly in Escherichia coli is one of the best studied efflux machines for conferring intrinsic multidrug resistance. This assembly is a representative of a wide family of homologous and analogous nanomachines, including those found in …
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On the Structure and Function of Multidrug Efflux Pumps
… called AcrZ with the tripartite complex AcrAB/TolC, in connection with the lipid environment, and the resulting changes in the latter’s functionality (Chapter 2). A regulatory role of the native membrane lipid environment as well as of small proteins for efflux pump activity have previously …
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The effects of nutrient limitation and growth rate on the regulation of the multi-drug pump genes acrAB in escherichia coli
… gàne products of the multi-drug ef flux acrAB-tolC operon. The primary regulation of acrAB has been investigated in these studies and it has been established by chemostat culture that the expression of acrAB was inversely related to growth rate, and this was irrespective of the limiting …
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The interplay between pathogenic bacteria and bacteriophage Chi: New directions in motility and phage-host interactions in Enterobacterales
… making the key discovery that the AcrABZ-TolC multi-drug efflux system is required for infection to proceed. We additionally found that the host molecular chaperone trigger factor is important for the χ phage lifecycle. In Chapter III, we outline our characterization of the initial binding …
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Molecular analysis of small RNA and small protein regulation of Escherichia coli stress responses
… evidence that the multidrug efflux channel TolC may be involved as tolC mutants exhibit impaired αMG efflux and more impaired growth when combined with an sgrS mutation. While the benefits of SgrS and SgrT to E. coli physiology are clear, the role of the sRNA DicF remains elusive. DicF is …
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Isolation and characterization of channel-forming proteins in the outer membrane of E. coli and Borrelia species
… investigated. In the second part the putative TolC homologue BB0124 of B. burgdorferi, the Lyme borreliosis agent, was studied. In the last part the influence of point mutants within the greasy slide of the maltose specific porin (LamB) of E. coli were shown. In the first part of this study …
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Estudo de virulência de Salmonella spp. isolados de linfonodos mesentéricos suinos: uma abordagem utilizando o sequenciamento de genoma completo
… ttrC, spiC, mgtC, sopB, pagN, sodC1, phoP, phoQ, tolC, sdiA, entF, fhuA, leuO, oxyR, slyA, fimA, flgL, flgK, fliC) apresentaram 100% de frequência nos isolados. Os genes relacionados as ilhas de patogenicidade, regulação, fimbrias e flagelos se mostraram bem conservados em todos os genomas …
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Characterizing and Overcoming Resistance to Aminomethylspectinomycins in Gram-negative Bacteria
… APH (9)-Ia and ANT (3")(9) in E.coli K12 and JW ΔtolC strains. Our agar-based enzyme assay shows the inactivation of spectinomycin by APH(9)-Ia. Phosphorylated spectinomycin and adenylated spectinomycin products upon incubation with APH(9)-Ia and ANT(3",9), respectively, have been identified using …
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From gut microbiome to pathogen genomics: Understanding antimicrobial resistance in Southeast Asia and Salmonella Paratyphi A
… to mutations in the acrB gene of the AcrAB-TolC efflux system. The impact of these mutations on resistance mechanisms was explored, highlighting their contribution to the growing threat of resistance in typhoidal Salmonella. Among the 132 AMR genes identified in the human gut of a Southeast …
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Structural and Mechanistic Studies of Multidrug Resistance Efflux Pumps in Multiple Families
… most well-studied drug efflux complexes: AcrAB-TolC. Though numerous structures exist for this multi-protein assembly, none have been obtained without use of detergents that displace natural lipids which may be needed to support key allosteric states. To better characterize lipid interactions …
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The role of coordinated regulation and aromatic metabolites in activating the mar/sox/rob regulon of Escherichia coli
… the reduction in OmpF expression in tolC mutants is found to be the result of Rob-dependent activation of MicF. Finally, genetic and biochemical data is presented that demonstrates the role of aromatic metabolites in activating the mar/sox/rob regulon through direct interaction with …
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Assay Setup for High Throughput Screening to Identify Novel Efflux Pump Inhibitors against Escherichia coli
… efluksipumppu on kolmiosainen AcrAB-TolC-proteiinikompleksi, joka ulottuu koko soluseinärakenteen läpi, pumpaten solun sisältä solunulkoiseen tilaan laajan kirjon rakenteellisesti toisistaan poikkeavia yhdisteitä, aiheuttaen lopulta ristilääkeaineresistenssiä useammalle eri …
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Interactions of Environmental Pollutants with Human Gut Bacteria
… increased PFAS bioaccumulation when lacking TolC efflux pump, indicating trans-membrane transport in PFAS bioaccumulation. PFAS bioaccumulation by specific gut bacteria is further supported by morphological changes observed in transmission electron microscopy and physiological changes as …