Abstract: Staphylococcus aureus can bind a number of different extracellular matrix proteins. Recent studies have shown that one particular Staphylococcus protein has the capacity of binding several different matrix proteins. The gene encoding this staphylococcal protein has been cloned and sequenced and the nucleic acid and amino acid sequences are provided as a feature of the present invention. This staphylococcal protein has a high degree of homology with eukaryotic MHC Class II antigens. Further analyses of the binding specificities of this protein reveal that it functionally resembles an MHC II antigen in that it binds synthetic peptides. Additionally, the present invention provides a vaccine and an in vivo vaccine against staphylococcal infections, and methods for using same.