Protein A; Plays a role in the inhibition of the host innate and adaptive immune responses. Possesses five immunoglobulin-binding domains that capture both the fragment crystallizable region (Fc region) and the Fab region (part of Ig that identifies antigen) of immunoglobulins. In turn, Staphylococcus aureus is protected from phagocytic killing via inhibition of Ig Fc region. In addition, the host elicited B-cell response is prevented due to a decrease of antibody-secreting cell proliferation that enter the bone marrow, thereby decreasing long-term antibody production. Inhibits osteoge [...]

Glutamyl endopeptidase precursor, putative; Preferentially cleaves peptide bonds on the carboxyl-terminal side of aspartate and glutamate. Along with other extracellular proteases it is involved in colonization and infection of human tissues. Required for proteolytic maturation of thiol protease SspB and inactivation of SspC, an inhibitor of SspB. It is the most important protease for degradation of fibronectin-binding protein (FnBP) and surface protein A, which are involved in adherence to host cells. May also protect bacteria against host defense mechanism by cleaving the immunoglobu [...]

Lipase precursor.

Transcriptional regulator, merR family, putative.

Alpha-hemolysin precursor; Alpha-toxin binds to the membrane of eukaryotic cells resulting in the release of low-molecular weight molecules and leading to an eventual osmotic lysis. Inhibits host neutrophil chemotaxis to the lesion region (Probable). Heptamer oligomerization and pore formation is required for lytic activity (By similarity). Belongs to the aerolysin family.

Cysteine protease precursor, putative; Cysteine protease that plays an important role in the inhibition of host innate immune response. Degrades host elastin, fibrogen, fibronectin and kininogen. Blocks phagocytosis of opsonised S. aureus by neutrophils and monocytes by inducing their death in a proteolytic activity-dependent manner. Decreases surface expression of the 'don't eat me' signal CD31 on neutrophils. Cleaves host galectin- 3/LGALS3, thereby inhibiting the neutrophil-activating ability of the lectin.

Serine protease SplC.

Clumping factor; Cell surface-associated protein implicated in virulence. Promotes bacterial attachment exclusively to the gamma-chain of human fibrinogen. Induces formation of bacterial clumps, which diminish the ability of group IIA phospholipase A2 to cause bacterial phospholipid hydrolysis and killing. Significantly decreases macrophage phagocytosis possibly thanks to the clumps, clumped bacteria being too large to be phagocytosed. Dominant factor responsible for human platelet aggregation, which may be an important mechanism for initiating infective endocarditis. Enhances spleen c [...]