TABLE 2.
Growth of E. coli strains in LB and M63 with added SDSa
| Strain | Protein(s) with mutation | Growth (Klett units) with SDS at:
|
||
|---|---|---|---|---|
| 10% | 5% | 0.5% | ||
| SG20250 | None (parent, MC4100) | 105 ± 3 | 130 ± 3 | 215 ± 0 |
| JT4000 | Lon | 107 ± 5 | 142 ± 2 | 232 ± 1 |
| KNSR-1 | ClpP | 7 ± 5 | 1 ± 0 | 23 ± 5 |
| KNSR-2 | ClpA | 4 ± 0 | 42 ± 9 | 198 ± 5 |
| KNSR-3 | ClpX | 2 ± 0 | 38 ± 5 | 143 ± 7 |
| KNSR-8 | ClpB | 2 ± 0 | 5 ± 0 | 11 ± 0 |
| SG22178 | ClpA and ClpX | 30 ± 6 | 42 ± 5 | 198 ± 10 |
| SG22091 | ClpA, ClpB, and ClpX | 1 ± 0 | 2 ± 0 | 5 ± 0 |
| KNSR-4 | ClpX ClpP | 7 ± 2 | 9 ± 0 | 15 ± 4 |
| KNSR-5 | ClpA ClpP | 2 ± 0 | 8 ± 0 | 19 ± 2 |
| KNSR-6 | ClpB ClpP | 1 ± 0 | 5 ± 5 | 16 ± 9 |
a
Cultures were grown at 37°C in LB with 0.1% glucose, the appropriate antibiotic, and the indicated concentration of SDS in 250-ml Nephalo flasks with 14-mm-diameter side arms. Growth levels were recorded on a Klett colorimeter with a red 660-nm filter. Values are averages of triplicate experiments with standard errors. For the clpP mutants, the absence of growth was confirmed by plate counts on LB agar. Cellular responses to SDS were the same for growth in LB (rich) and defined M63 (18) media except for the clpA clpX double mutant, which exhibited some growth in LB plus 10% SDS but no growth in M63 plus 10% SDS.