Table 1.
The effect of the MtrC hairpin on the vancomycin resistance of Escherichia coli cells expressing MtrE
| Strain | Vancomycin sensitivity (mm) |
|---|---|
| MtrE | NI |
| MtrE/MtrC | 9 ± 1 |
| MtrE E434K | NI |
| MtrE E434K/MtrC | NG |
| MtrE E434K/gIII-NT-MtrC | NG |
| MtrE/gIII-Hairpin | NI |
| MtrE E434K/gIII-Hairpin | NI |
| MtrC/MtrD/MtrE | NI |
| MtrC/MtrD/MtrE E434K | 10 ± 1 |
The indicated MtrE proteins were expressed from pACYC (and pET21a) and the MtrC and hairpin, with an N-terminal gIII signal sequence, proteins from pET24a in KAM3(DE3) E. coli cells in the presence of 30 μg of vancomycin. The inhibitory zone diameter is given in mm. All disc-diffusion assays were undertaken in triplicate and the average result given. Abbreviations: NI, no inhibition of growth; NG, no growth.