TABLE 1.
Binding and inducing properties of mutant proteins
| Activator | Fold activation from:
|
Fold repression from O1-pCc | |
|---|---|---|---|
| I1-I2-pBADa | pFGHb | ||
| None (no AraC) | 1 | 1 | 1 |
| AraC | 100 | 190 | |
| H213Y AraC | 59 | 90 | |
| Parental chimera | 63 | 21 | 16 |
| H213Y chimera | 4 | 15 | 12 |
a
Activation from I1-I2-pBAD was quantitated with the arabinose isomerase assay. The strain without parental chimeric AraC contained 140 arabinose isomerase units, and that with the parental chimera contained 8,600 arabinose isomerase units.
b
Activation from pFGH-lacZ was measured by the β-galactosidase assay. The strain with parental chimeric AraC contained 4,200 Miller units, and the strain without AraC contained 200 Miller units.
c
Repression from pC-lacZ in cells grown in the absence of arabinose was quantitated with the β-galactosidase assay. The strain with parental chimeric AraC contained 10 Miller units, and the strain without AraC contained 160 Miller units.