Suppressive mutations do not stimulate promoters of replication genes

§Promoter activity was measured in PykA+ and PykA− strains carrying (i) the lacZ ORF downstream of the promoter of dnaE, dnaC or polC and (ii) the replication genes under the control of Pspac-I. The β-galactosidase activity was measured in cells growing exponentially at 37°C in LB containing 1 mM IPTG (in these growth conditions, the IPTG-driven expression of dnaE, dnaC and polC has no effect on cell growth and morphology [5], [93], [96]. Values correspond to Miller units/mg.