FIG. 6.

Transcriptional activation of the σ³²-controlled groESL promoter. Expression from the groESL promoter was determined using the E. coli groESL::lacZ reporter strain SR6618 and β-galactosidase assays. A significant increase in β-galactosidase levels (▴) (P < 0.05) was observed between 60 and 90 min. Cell division was monitored by determination of cell counts (*) (cells/ml). Promoter activity is given as ΔmOD₄₂₀/min/OD₆₀₀. Means and standard deviations for three independent experiments, with each sample measured in duplicate, are plotted.