FIG. 6.

Northern blots of sarA, spa, and coa transcripts in the wild type, sarU mutant, trans-complemented strains, sarA, agr, and sarT mutants. A total of 10 μg of RNA was applied to each lane. RNAs extracted from the wild type (RN6390), various mutants, and complemented strains are from the exponential (OD₆₅₀, 0.7) and postexponential (OD₆₅₀, 1.7) phases. (A) The blot was probed with a 400-bp fragment containing the sarA open reading frame. The transcripts are the larger sarA P2 (1.2 kb), sarA P3 (0.8 kb), and the smaller sarA P1 (0.5 kb) transcripts, respectively (4). (B and C) The blot was hybridized with a 1.4-kb DNA fragment containing the spa gene (B) and a labeled 4.5-kb coa fragment of S. aureus as a probe (C).