Cross-Linked Complex between Oligomeric Periplasmic Lipoprotein AcrA and the Inner-Membrane-Associated Multidrug Efflux Pump AcrB from Escherichia coli
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TLDR
It is shown that AcrA protein forms oligomers, most probably trimers, in this oligomeric form, and interacts specifically with AcrB transporter independently of substrate and TolC.Abstract:
In Escherichia coli, the intrinsic levels of resistance to multiple antimicrobial agents are produced through expression of the three-component multidrug efflux system AcrAB-TolC. AcrB is a proton-motive-force-dependent transporter located in the inner membrane, and AcrA and TolC are accessory proteins located in the periplasm and the outer membrane, respectively. In this study, these three proteins were expressed separately, and the interactions between them were analyzed by chemical cross-linking in intact cells. We show that AcrA protein forms oligomers, most probably trimers. In this oligomeric form, AcrA interacts specifically with AcrB transporter independently of substrate and TolC.read more
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References
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Journal ArticleDOI
Blue native electrophoresis for isolation of membrane protein complexes in enzymatically active form.
TL;DR: The percentage recovery of functional activity depended on the respective protein complex studied and was zero for some complexes, but almost quantitative for others, and the recovery of all respiratory chain complexes was almost quantitative.
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AcrAB efflux pump plays a major role in the antibiotic resistance phenotype of Escherichia coli multiple-antibiotic-resistance (Mar) mutants.
TL;DR: The AcrAB system is identified as the major pump responsible for making the Mar mutants resistant to many agents, including tetracycline, chloramphenicol, ampicillin, nalidixic acid, and rifampin.
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Genes acrA and acrB encode a stress‐induced efflux system of Escherichia coli
Dzwokai Ma,David N. Cook,Marie Alberti,Ning G. Pon,Hiroshi Nikaido,John E. Hearst,John E. Hearst +6 more
TL;DR: The results suggest that one major physiological function of AcrAB is to protect E. coli against cephalothin and other hydrophobic inhibitors and mar (multiple‐antibiotic‐resistant) mutants.
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Molecular cloning and characterization of acrA and acrE genes of Escherichia coli.
TL;DR: The DNA fragment containing the acrA locus of the Escherichia coli chromosome has been cloned by using a complementation test and nucleotide sequence indicates the presence of two open reading frames (ORFs) that encodes a 397-residue lipoprotein with a 24-amino-acid signal peptide at its N terminus.
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Evidence that TolC is required for functioning of the Mar/AcrAB efflux pump of Escherichia coli.
TL;DR: A study examining the influence of TolC on AcrA, AcrR, and MarR1 mutants indicates that functional TolC is required for the operation of the AcrAB efflux system and for the expression of the Mar phenotype.