Regulatory protein involved in autolytic activity, multidrug resistance and virulence (By similarity). Negatively controls spa (surface protein A) transcription. Activates type 8 capsular polysaccharide (cap8) and nuclease (nuc) biosynthesis. Represses coagulase and protease production. In strain Becker, gene disruption may lead to increase in alpha-hemolysin (hla).