TABLE 1.
Expression of genes HXT1, HXT7, SUC2, and MTH1 in different yeast strainsa
| Gene | Strain genotype | Activity (nmol min−1 mg of protein−1)c on:
|
|||
|---|---|---|---|---|---|
| 2% Glucose | 2% Maltose | 2% Raffinose | 2% Ethanol | ||
| HXT1 | Wild type | 129 | 2 | 4 | <1 |
| HTR1-23 | <1 | <1 | <1 | <1 | |
| mth1Δ | 128 | 3 | 3 | 14 | |
| HXT7 | Wild type | 3 | 300 | 1,290 | 820 |
| HTR1-23 | 62 | 25 | 35 | 100 | |
| mth1Δ | 3 | 450 | 3,030 | 4,500 | |
| snf3Δ | —b | — | 86 | 166 | |
| grr1Δ | — | — | 38 | 67 | |
| snf3Δ rgt1Δ | — | — | 1,307 | — | |
| HTR1-23 rgt1Δ | 28 | 106 | 670 | 981 | |
| HTR1-23-YEpMTH1 | 230 | 65 | 200 | 190 | |
| Wild type-YEpMTH1 | 200 | 180 | 510 | 220 | |
| MTH1 | Wild type | 1 | 60 | 105 | 100 |
| HTR1-23 | 30 | 12 | 25 | 30 | |
| mth1Δ | 1 | 110 | 230 | 430 | |
| SUC2 | Wild type | 2 | 37 | 866 | — |
| HTR1-23 | 280 | 21 | 99 | — | |
| mth1Δ | 2 | 53 | 1,338 | — | |
| HTR1-23-pFM-HXT1 | 13 | — | — | — | |
| hxt1-7Δ | 980 | — | 1,240 | — | |
a
Cells were grown for about 15 h in YP medium or, in the case of plasmid-bearing cells, in YNB medium lacking uracil supplemented with different carbon sources to a density of 1 × 107 to 3 × 107 cells/ml. Mean values of data from at least two independent experiments are given. Standard deviations were less than 15%.
b
—, not determined.
c
For HXT1, HXT7, and MTH1, β-galactosidase activity; for SUC2, invertase activity.