Fig. 5

(A) Growth curves of S. aureus USA300 WT cultured in SMM minimal medium supplemented with 0.5% glucose or fructose. (B) RT-qPCR analysis of fruRKT gene expression levels in SMM minimal medium supplemented with 0.5% glucose or fructose. Expression levels were normalized to the baseline measurements obtained prior to the introduction of either sugar. (C) The pQLV003 derived P_fruRKT_lacZ reporter plasmid was transformed into S. aureus WT, Δ03670 and Δ03675 strains. The lacZ enzyme activity of the cell lysates of each strain growing in the presence or absence of fructose was measured. (^****P ≤ 0.0001 relative to the level without fructose induction. ns, not significant). Each assay was performed three times and the data was presented as the mean plus standard deviation. (D) D-Fructose 1-phosphate (D-Fru-1-P) disrupted the binding of the FruR protein to the promoter sequence DNA fragment. Glucose (Glu) and galactose (Gla) at a concentration of 200 μM each were employed as controls