TABLE 4.
Gal4p can activate PUT2 gene expression in the absence of Put3p
| Strainb | Relevant genotype | Plasmid | β-galactosidase net sp acta
|
|
|---|---|---|---|---|
| −Gal | +Gal | |||
| MB838-3C | PUT3 GAL4 PUT2-lacZ | None | 41 | 40 |
| MB838-1B | PUT3 gal4Δ PUT2-lacZ | None | 40 | 19 |
| MB838-2A | put3Δ GAL4 PUT2-lacZ | None | 0 | 19 |
| MB838-2A | put3Δ GAL4 PUT2-lacZ | pMDB6c | 0 | 100 |
| MB838-2B | put3Δ gal4Δ PUT2-lacZ | None | 0 | 0 |
The put3Δ galΔ strain produced a background β-galactosidase specific activity of 22 U in the absence of galactose and 35 U in the presence of galactose. This activity was subtracted from the total activity of each strain under each condition. Values are the averages of three determinations; variation was ≤17%.
Strains MB838-3C, MB838-1B, MB838-2A, and MB838-2B were grown on minimal media containing glucose (0.05%), with or without galactose (2%), and ammonium sulfate (0.2%), adenine sulfate (20 mg/liter), and uracil (20 mg/liter). Uracil was omitted when the strain carried the plasmid.
Plasmid pMDB6 carried a copy of the GAL4 gene under the control of the constitutive ADH1 promoter.