Overexpression of nuc in a codY mutant requires saeR. Strains were grown exponentially and nuc transcript abundance measured using qRT-PCR. Data are presented as the mean ± standard error of at least two independent experiments. A. UAMS-1: WT, SRB337; codY::erm, SRB372; codY::erm saeR::φΝΣ[erm::tet(M)], SRB759. B. USA300 LAC: WT, SRB687; codY, SRB746; codY saeR::φΝΣ[erm::tet(M)], SRB761. C. Loss of CodY-mediated repression at saePQRS leads to subsequent loss of nuc repression. CodY-repressed gene targets coding for the Sae TCS (saePQRS) and thermonuclease (nuc) are shown. Values in CodY variant strains are presented as a percentage of the value obtained in the codY mutant strain, set to 100% expression.