FIG. 1.

Effects of regulatory mutations on exoprotein production in S. aureus SDS–10% (wt/vol) polyacrylamide gels show total extracellular protein production during growth as described in Materials and Methods. (A) S. aureus 8325-4 lanes 1 to 4 and PC1839 (sarA) (lanes 5 to 8) at T = 2, 4, 6, and 8 h, corresponding to log, early and late post-exponential, and stationary phases of growth, respectively. (B) S. aureus 8325-4 (lane 1), PC6911 (agr) (lane 2), PC1839 (sarA) (lane 3), and PC18391 (sarA agr) (lane 4), all in stationary phase (T = 8 h). All lanes contain exoproteins from the equivalent of 0.05 OD₆₀₀ units of original culture. Representative sarA-regulated proteins are indicated by arrows. The molecular masses of protein standards (in kilodaltons) are shown.