TABLE 1.
Effect of mutations in the LDEVFL or CREEM motif on doxorubicin resistance
E. coli N43 cells carrying the indicated mutation on a plasmid were streaked on M9 plates containing different concentrations of doxorubicin. The growth was scored after incubation of the plates for 24 h at 37 °C. +++, very good growth; ++, good growth; +, some growth; +/−, very weak growth; −, no growth. This experiment was repeated four times. Dox, doxorubicin.
| Motif of DrrA | Mutation | 0 μg/ml Dox | 4 μg/ml Dox | 6 μg/ml Dox | 8 μg/ml Dox | 10 μg/ml Dox |
|---|---|---|---|---|---|---|
| Vector | +++ | − | − | − | − | |
| Wild type | +++ | +++ | +++ | +++ | ++ | |
| CREEM | E321D/E322D/E325D | +++ | +++ | ++ | + | − |
| CREEM | E321G/E322G/E325G | +++ | +++ | ++ | + | − |
| CREEM | E321Q/E322Q/E325Q/E326Q | +++ | +++ | ++ | + | − |
| CREEM | E321G/E322G/E325G/E326G/E327G | +++ | − | − | − | − |
| CREEM | CREEM deletion | +++ | − | − | − | − |
| LDEVFL | L303V | +++ | − | − | − | − |
| LDEVFL | D304N | +++ | ++ | + | +/− | − |
| LDEVFL | V306A/F307A/L308A | +++ | − | − | − | − |
| LDEVFL | L310A/T311A/G312A | +++ | − | − | − | − |
| LDEVFL | LDEVFL deletion | +++ | − | − | − | − |