Table 3.
Competition between Pol I, Pol II and Pol IV DNA polymerases.a
| lac G·C→T·A (per 108) | ||||
|---|---|---|---|---|
| Strain |
lac orientation (strand) |
polA+ | polAexo | polAexo effect |
| A. mutL strains | ||||
| dnaE+ | R(lagging) | 3.3 ± 0.9 | 9.1 ± 2.8 | 2.7 |
| dnaE+ ΔdinB | R(lagging) | 4.0 ± 1.2 | 11.5 ± 1.3 | 2.9 |
| dnaE+ ΔpolB | R(lagging) | 3.0 ± 1.2 | 10.5 ± 2.7 | 3.5 |
| dnaE+ ΔdinB ΔpolB | R(lagging) | 4.6 ± 1.8 | 12.4 ± 2.7 | 2.7 |
| B. mutL+ strains | ||||
| dnaE486 | R(lagging) | 4.2 ± 1.7 | 5.9 ± 2.2 | 1.4 |
| dnaE486 ΔdinB | R(lagging) | 2.7 ± 1.3 | 3.1 ± 1.4 | 1.1 |
| dnaE486 ΔpolB | R(lagging) | 8.4 ± 2.5 | 6.3 ± 3.9 | 0.8 |
| dnaE486 ΔdinB ΔpolB | R(lagging) | 0.8 ± 0.6 | 1.3 ± 0.7 | 1.6 |
a
The experiments were performed with the lac G·C→T·A allele in the R(lagging) orientation. The mutL strains were mutL::Tn10. Mutant frequencies were determined as described in Experimental procedures. Each entry is based on the median value for 10 independent cultures grown at 37°C (dnaE+) or 34°C (dnaE486). No statistically significant effects are observed for the ΔpolB, ΔdinB, or ΔpolB ΔdinB strains in the polA+ dnaE+ series (both mutL+ and mutL) (P > 0.05). The corresponding differences in the polA+ dnaE486 series are significant (P < 0.05).
Statistically significant polAexo mutator effects are indicated in bold.