Table 2.
Leakage of β-galactosidase into the medium of cells lacking folding factorsa
| Strain or relevant genotype | β-Galactosidase activity (μmol/min) |
|---|---|
| Strain BW30270 (wt) | <1 |
| surA | 43 |
| ppiD | <1 |
| fkpA | 1 |
| dsbA | 4 |
| dsbC | <1 |
| tsp | 9 |
| degP | 5 |
| ptrA | 1 |
| yfgC | 2 |
| ydgD | 1 |
| dsbA fkpA | 10 |
| degP dsbA | 41 |
| degP yfgC | 13 |
| degP tsp | 81 |
| surA dsbC | 24 |
| tsp fkpA | 23 |
| tsp ydgD | 24 |
| tsp ppiD | 7 |
a
Mutant strains were grown to mid-log phase in liquid rich medium at 37°C. Activity of cytoplasmic β-galactosidase in cell culture supernatant was determined as an indicator of a membrane defect. Assays were done with two biological and three statistical replicates, and standard deviation was <40%. Total β-galactosidase activity of cells was on average 970 μmol/min.