Figure 4From: Translational independence between overlapping genes for a restriction endonuclease and its transcriptional regulatorExpression of pvuIIC-lacZ and pvuIIR-lacZ translational fusions in the presence and absence of C.PvuII. Cultures of E. coli TOP10 were grown in exponential phase in defined rich medium containing IPTG, and samples were taken at several times for β-galactosidase assays. If the cells are in balanced growth, the plot of activity vs. culture density should be linear. The translational fusions were to pvuIIC (open circles) or pvuIIR (closed circles), and in both cases are transcribed from a C-independent vector promoter. The equations resulting from linear regression are shown. A. A compatible plasmid is providing active C.PvuII in trans. B. As in (A), except the plasmid is providing an inactive version of C.PvuII.Back to article page