Fig. 3.

Effect of agr on PSM expression in various strain backgrounds. (A) Expression of the psmα and psmβ operons was determined using qRT-PCR as previously described (35). (B) Concentrations of all S. aureus PSMs (see legend) in culture filtrates were measured as described previously (35). Samples for measurements were taken from 8-h (strains LAC and RN6390) or 10-h (strain 252) cultures. Striped parts of bars represent the N-deformylated fraction of a particular PSM. Note that strain 252 contains the psm-mec gene in contrast to strains LAC and RN6390.