Fig. 6

Comparison of two ECF σ/anti-σ switches encoded on medium copy plasmid and chromosomally integrated. Optical density (measured at 600 nm) and luciferase activity (shown in relative luminescence units normalized by the optical density measured at 600 nm) from an ECF16 σ-dependent promoter (a) and an ECF22 σ-dependent promoter (b), in presence or absence of the cognate anti-σ. The growth defects observed in both circuits encoded on medium copy number plasmids are abolished when integrated into the genome, while the ability of the anti-σ to sequester the cognate ECF σ is maintained. The data indicate averages from three independent biological assays and error bars denote standard deviations