Involved in countering the first line of host defense mechanisms. Specifically inhibits the response of human neutrophils and monocytes to complement anaphylatoxin C5a and formylated peptides, like N-formyl-methionyl-leucyl-phenylalanine (fMLP). Acts by binding directly to the C5a receptor (C5aR) and formylated peptide receptor (FPR), thereby blocking the C5a- and fMLP-induced calcium responses. Prevents phagocytosis of the bacterium. Chemotaxis inhibitory Protein, S. aureus (strain MRSA252), Recombinant (His) is expressed in yeast with N-6xHis tag. The predicted molecular weight is 16.1 kDa and the accession number is Q6GFB3.