TABLE 1.

Strains and plasmids

Strain or plasmidDescription or genotypeReference or source
Strain
    DH5αF φ80lacZΔM15 Δ(lacZYA-argF) U169 endA1 recA1 hsdR17 (rK, mK+) supE44 thi-1 gyrA96 relA1 phoA 33
    CE43(DE3)Membrane protein overproducer selected from BL21(DE3) [E. coli B FompT hsdSBgal dcm (DE3)] 21
    HNCE1b marR1 ΔacrA::cat ΔacrB::kan ΔacrD 5
Plasmid
    pUC151AA 6.5-kb bglII fragment containing the entire acrAB operon cloned into pUC19 vector 17
    pAcrB acrB gene cloned into pSportI high-copy-number cloning and expression vector; amp, lac-inducible expression 5
    pAcrABpAcrB containing acrA gene cloned upstream of acrBThis study