Mutation in the predicted porter domain of MexB affected the selective efflux of aycl-HSLs by MexAB-OprM.P. aeruginosa strains were grown in LB medium with acyl-HSLs, and lasB expression analyses were performed as described in Materials and Methods. Promoter activities are expressed in fluorescence intensities (arbitrary units) depending on amounts of green-fluorescence protein (GFP) derived from PlasB-gfp at emission (490 nm; excitation, 510 nm). The following MexB mutant strains were used: KG7403, KG7503, KG7503 carrying pKTA113 (wild-type MexB), pYT57 (MexB Phe136Ala), and pYT81 (MexB Asp681Ala). The data represent mean values of three independent experiments. Error bars represent the standard errors of the means.
Minagawa et al. BMC Microbiology 2012 12:70 doi:10.1186/1471-2180-12-70