Fig. 5From: Escherichia coli σ70 promoters allow expression rate control at the cellular level in genome-integrated expression systemsSchematic of lac operators in the native lac operon (top panels) and its regulation of the gene of interest (bottom panels). Lacl (pink tetramer) production effects are shown, when the promoter for the gene of interest was regulated by a one lac operator or b two lac operators, respectively. Ka = association constant; red cross = stopped productionBack to article page