FIG. 4.

Western and Northern analyses of the alpha-hemolysin gene product. (A) An immunoblot of extracellular proteins of ALC1001, its isogenic parent RN6390, and complemented strain ALC1497 from the late log phase was probed with rabbit anti–alpha-hemolysin antibody (1:2,500 dilution). (B) Ten micrograms of total cellular RNA obtained from the late log to early stationary phases was applied to each lane. The probe was a 3-kb EcoRI-HindIII fragment of the alpha-hemolysin gene (7). Similar complementation results were obtained with another sigB mutant (RUSA168) and plasmid pALC1496. These experiments were repeated three times, with similar results. The results of a representative experiment are shown.