Causative agent of the symptoms associated with scarlet fever, have been associated with streptococcal toxic shock-like disease and may play a role in the early events of rheumatic fever. Superantigen that binds to major histocompatibility complex class II beta chain in a zinc-dependent manner, it may activate up to 20% of all T-cells. Superantigens bind simultaneously TCRs and MHC class II molecules resulting in a massive release of pyrogenic and inflammatory cytokines (By similarity). Belongs to the staphylococcal/streptococcal toxin family.