Involved in biofilm formation, cell division, autolysis and the regulation of acid and oxidative stress tolerance. May be associated with systemic virulence in blood. Cells form longer chains and sparse microcolonies, are more resistant to phagocytosis, show greater level of platelet aggregation, but are unable to form biofilm at least in vitro. As a result of luxS inactivation, brpA expression was decreased by 70% in early-exponential-phase cells. Also, brpA expression was down-regulated in response to the deficiency of smu486 and smu487. Belongs to the LytR/CpsA/Psr (LCP) family.