TABLE 1.
Effects of position +3 promoter mutations on expression and regulation of short and long carAp1::lacZ operon fusions
| Strain (carAp1 mutation) | Promoter region length | β-Galactosidase activity (nmol/min/mg)a
|
Fold regulation | |
|---|---|---|---|---|
| Uracil | UMP | |||
| CLT5174 (none [wtb]) | Shortc | 992 | 2,820 | 2.8 |
| CLT5175 (T to G) | Short | 3,610 | 4,910 | 1.4 |
| CLT5177 (T to C) | Short | 2,040 | 2,430 | 1.2 |
| CLT5192 (none [wt]) | Longd | 132 | 2,340 | 18 |
| CLT5202 (T to G) | Long | 563 | 3,480 | 6.2 |
| CLT5203 (T to C) | Long | 305 | 2,710 | 8.9 |
a
Values are the means of at least three independent determinations with a variation of <8%. Doubling times were 46 ± 2 min for cells grown on uracil and 68 ± 2 min for cells grown on UMP.
b
wt, wild type.
c
The short carAB P1 promoter region contained bp −58 to +40.
d
The long carAB P1 promoter region contained bp −355 to +40.