Figure 4.

Accessory gene regulator quorum sensing system in Staphylococcus aureus. Homologous short peptide signaling systems exist in other Gram-positive bacterial species and genera. agr, accessory gene regulator; AIP, autoinducer peptide; P, promoter site; P*, phosphorylated protein; RAP, RNAIII-activating protein; RIP, RNAIII-inhibiting peptide; TRAP, target of RNAIII-activating protein.