FIG. 2.

sarT genes and expression. (A) Southern blot. Genomic DNAs extracted from a collection of S. aureus and other staphlyococcal species were digested with HindIII (expected fragment size, 9,470 bp) and probed with a 0.4-kb fragment encompassing the putative sarT. The sarT probe did not hybridize with chromosomal DNA from S. epidermidis or S. haemolyticus. (B) Northern blots to determine if the sarT message is influenced by the sarA/agr regulatory system. RNA extracted from wild-type (RN6390) and mutant strains of S. aureus was probed with ³²P-labeled sarT at exponential phase (OD₆₅₀ = 0.7) (lane 1), late exponential phase (OD₆₅₀ = 1.1) (lane 2), and postexponential phase (OD₆₅₀ = 1.7) (lane 3).