TABLE 3.
AmrZ residues Lys18, Val20, and Arg22 are absolutely required for repression of amrZ transcriptiona
| Strain | Genotype | AmrZ expressed | Avg β-galactosidase activity (Miller units) ± SD | % of wild-type activity |
|---|---|---|---|---|
| FRD1310 | mucA22 attB::amrZ-lacZ | Wild type | 2,054 ± 41 | 100 |
| FRD1312 | mucA22 amrZ::xylE aacC1 attB::amrZ-lacZ | 3,157 ± 214 | 154 | |
| FRD2528 | mucA22 amrZ37 attB::amrZ-lacZ | AmrZ R14A | 1,588 ± 38 | 77 |
| FRD2530 | mucA22 amrZ17 attB::amrZ-lacZ | AmrZ K18A | 3,913 ± 100 | 191 |
| FRD2532 | mucA22 amrZ18 attB::amrZ-lacZ | AmrZ V20A | 4,377 ± 109 | 213 |
| FRD2503 | mucA22 amrZ19 attB::amrZ-lacZ | AmrZ R22A | 3,946 ± 104 | 192 |
a
Single-copy amrZ-lacZ transcriptional fusions were placed at the neutral attB site in isogenic amrZ+ (FRD1310), AmrZ R14A (FRD2528), AmrZ K18A (FRD2530), AmrZ V20A (FRD2532), and AmrZ R22A (FRD2503) strains of P. aeruginosa. All strains were engineered in an FRD1 (mucA22) background. β-Galactosidase activity was recorded in Miller units, and results are average data from three separate experiments. Percentages of wild-type values are also listed for comparison purposes.