Table 4. Analysis of expression of HMR GAL1pro::a1 in gal4 mutants.
| Gal4 Allele | DNA Binding Affinitya (% of WT) | GAL1pro::a1 mRNA in sir4∆ as a Percentage of Gal4, sir4∆, GAL1pro::a1 mRNA Expression (%) | Ratio of Gal1pro::a1, sir4∆ mRNA /GAL1pro::a1, SIR mRNA (sir4∆/SIR) | Gal1pro::a1, sir4∆ mRNA |
|---|---|---|---|---|
| WT (GAL4) | 100 | 100 | 1.7 | 2.51 ± 0.12 |
| gal4-147∆768 | 51.7 | 118 | 2.5 | 2.96 ± 0.08 |
| gal4-238∆768 | 75.6 | 63.8 | 1.8 | 1.60 ± 0.06 |
| gal4-763∆851 | 19.1 | 47 | 11.5 | 1.79 ± 0.21 |
| gal4-238∆851 | 28.7 | 8.9 | 10.9 | 0.223 ± 0.01 |
| gal4-848∆ | 85.1 | 5 | 22 | 0.125 ± 0.2 |
| gal4-844∆ | 46.6 | 4.8 | 22.8 | 0.121 ± 0.21 |
| gal4∆ | 0 | 0.4 | ND | 0 ± 0.01 |
a1 transcript levels from GAL1pro::a1 as determined by qRT-PCR in SIR4 and sir4∆ strains upon GAL induction and media switch from noninducing (raffinose) to inducing (galactose) carbon sources. All a1 expression values were normalized to ACT1 mRNA and further to the a1/ACT1 mRNA ratio in HMRa1 sir4∆ strains. Each mRNA expression number represents the average and SEM for three biological replicates.
a
DNA binding affinity of gal4 mutants calculated based on filter binding assay described in Ma and Ptashne (1987).