The acrAB locus is involved in modulating intracellular acetyl coenzyme A levels in a strain of Escherichia coli CM2555 expressing the chloramphenicol acetyltransferase (cat) gene.
Recently, an Escherichia coli CM2555 strain was described as sensitive to chloramphenicol when expressing the chloramphenicol resistance gene (cat) from a multicopy plasmid. This sensitivity was linked to dysfunction of the acrA gene, which encodes a component of the AcrAB-TolC multidrug efflux pump. Preliminary data indicate that the sensitivity phenotype might be due to a decline in intracellular acetyl coenzyme A concentration accompanying the reaction catalyzed by chloramphenicol acetyltransferase, the cat-encoded resistance protein. Here, we demonstrate that the acrA dysfunction is the factor impairing the intracellular acetyl coenzyme A levels in the cat-expressing CM2555 strain. This effect might be alleviated by the interplay of proteins constituting two homologous efflux systems: AcrAB-TolC and AcrEF-TolC. However, our results show also that this is a genetic background-specific phenomenon, as the decrease in acetyl coenzyme A level is not evident in a cat-bearing DeltaacrAB derivative of the commonly used strain C600.
Potrykus
Joanna
J
Department of Molecular Biology, University of Gdansk, Kladki 24, 80-822 Gdansk, Poland.
Wegrzyn
Grzegorz
G
D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000378:metabolism*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000502:physiology*; D002701:Chloramphenicol / Q000494:pharmacology; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D005798:Genes, Bacterial; D008074:Lipoproteins / Q000235:genetics / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D026901:Membrane Transport Proteins / Q000235:genetics; D027425:ATP-Binding Cassette, Sub-Family C Proteins
D000085:Acetates; D000105:Acetyl Coenzyme A; D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D002352:Carrier Proteins; D002701:Chloramphenicol; D015500:Chloramphenicol O-Acetyltransferase; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C073126:tolC protein, E coli