TABLE 2.
Exonuclease III activity in crude cell extracts and resistance to hydrogen peroxide of the sppA-ansA-pncA insertion mutant and 42°C+ revertants
|
Strain |
Genotype | Exonuclease activitya | % survival after H2O2 treatmentb |
|---|---|---|---|
| LT2 | Wild type | 6.2 | 7.6 |
| TR6630 | sppA-ansA-pncA insertion | 245 | 26 |
| TR6632 | 42°C+ revertant of TR6630 | 5.9 | 4.0 |
| TR6633 | 42°C+ revertant of TR6630 | 5.6 | 7.7 |
| TR6634 | 42°C+ revertant of TR6630 | 5.4 | 5.4 |
| TR6635 | 42°C+ revertant of TR6630 | 4.7 | 7.1 |
| TR6636 | 42°C+ revertant of TR6630 | 4.8 | 19 |
| TR6637 | 42°C+ revertant of TR6630 | 5.8 | 29 |
| TR6638 | 42°C+ revertant of TR6630 | 6.8 | 4.1 |
| TR6639 | 42°C+ revertant of TR6630 | 3.8 | 0.2 |
| TR6640 | 42°C+ revertant of TR6630 | 5.4 | 7.7 |
| TR6641 | 42°C+ revertant of TR6630 | 5.5 | 8.5 |
a
Activity is expressed in micrograms of DNA degraded per minute per milligram of protein.
b
The percentage compares the number of viable colonies from cells exposed to 5 mM H2O2 for 30 min to the number of colonies from untreated cells.