Doubling time of E. coli ΔssrA or ΔsmpB mutants expressing SmpBHpWT, SsrAHpWT or mutants. Doubling times were calculated for E. coli strains expressing SmpBHp, SsrAHpand different mutant versions of SsrAHpfrom plasmids. Doubling times (g values) correspond to the mean generation time. As a control, growth complementation of the E. coli ΔssrA with Ec-ssrA is presented. Empty vector corresponds to a vector without insert.