AcrS/EnvR Represses Expression of the<i>acrAB</i>Multidrug Efflux Genes in<i>Escherichia coli</i>

Abstract

The acrS regulatory gene is located upstream of the acrEF multidrug efflux system genes. However, the roles of AcrS in regulation of drug efflux pumps have not been clearly understood. Here we show that AcrS represses other multidrug efflux genes, acrAB, which encode a major efflux system in Escherichia coli.