FIG 1.
Mupirocin and stationary-phase conditions stimulate (p)ppGpp sensor responses and inhibit malonyl-CoA production and accBC activity. S. aureus Newman strains contain reporter systems as indicated. Strains were grown in BHI and BHI containing 0.1 μg/ml mupirocin (Mupi) for 1 h (A and C), or in SerFA at exponential (A600∼4.0, Exp) and stationary phase (A600 ∼10.0, Stat) (B and D). PilvD-lacZ and PcshA-lacZ expression were evaluated by β-gal assays. Total malonyl-CoA levels were determined by immunoassay (ELISA) and deduced from PaccBC-lacZ expression. Genes ilvD and cshA are upregulated and downregulated, respectively, by stringent response induction. Data presented are means ± standard deviations from triplicate independent experiments. *, P ≤ 0.05 using the Mann-Whitney test.