TABLE 2.
Regulation of B. subtilis hemN and hemZ
| Strain | β-Galactosidase activity (U/mg of protein)a
|
|||
|---|---|---|---|---|
| +O2 | +H2O2b | −O2 | −O2 + 10 mM nitrate | |
| HZ01(hemZ::bgaB) | 9 | 52 | 4 | 47 |
| ARB1(hemZ::bgaB resDE) | 10 | NT | 3 | 10 |
| ARB2(hemZ::bgaB fnr) | 9 | NT | 2 | 4 |
| ARB3(hemZ::bgaB ywiD) | 14 | NT | 1 | 2 |
| AM10(hemN::bgaB) | 7 | 6 | 4 | 34 |
| ARB4(hemN::bgaB resDE) | 8 | NT | 4 | 8 |
| ARB5(hemN::bgaB fnr) | 9 | NT | 2 | 5 |
| ARB6(hemN::bgaB ywiD) | 9 | NT | 2 | 3 |
| AM7(bgaB) | 2 | 2 | 2 | 3 |
| ARB7(bgaB resDE) | 2 | NT | 2 | 2 |
| ARB8(bgaB fnr) | 3 | NT | 2 | 2 |
| ARB9(bgaB ywiD) | 2 | NT | 2 | 3 |
a
Strains were grown aerobically or anaerobically as described in Materials and Methods. All cell extracts were prepared and assayed for β-galactosidase activity as described before (28). The results represent averages of three different experiments performed in triplicate. A standard deviation of approximately 1.5 U/mg of protein was observed. NT, not tested.
b
Growing cultures were treated for 15 min with 0.1 mM H2O2 before assaying for reporter gene expression.