TABLE 5.
Effects of hypoxanthine and ammonium on expression from Φ(hpxD-lacZ) and Φ(hpxR-lacZ) constructs
| Strain | Fusionb | hpxRc | LacZ sp acta
|
||
|---|---|---|---|---|---|
| − Hyx/ + NH4+ | − Hyx/ − NH4+ | + Hyx/ − NH4+ | |||
| VJSK2966 | Φ(hpxD-lacZ) | + | 7 | 42 | 2,420 |
| VJSK2968 | Φ(hpxD-lacZ) | − | <1 | <1 | <1 |
| VJSK2967 | Φ(hpxR-lacZ) | + | 30 | 40 | 29 |
| VJSK2969 | Φ(hpxR-lacZ) | − | 100 | 200 | 180 |
a
Strains were cultured to the mid-exponential phase in MOPS medium, with nitrate as the nitrogen source. Ammonium or hypoxanthine (Hyx) was added as indicated.
b
Operon fusion construct integrated at the chromosomal rha locus.
c
+, hpxR+; −, hpxR113::Ω-Cm.