High Resolution Solution NMR Structure of the Z Domain of Staphylococcal Protein A. Analysis of Secondary Structure for Free Z Domain and Bounded to IgG Antibody

Staphylococcal protein A (SpA) is a cell-wall-bound pathogenicity factor from the bacterium Staphylcoccus aureus. It exhibits tight binding to many IgG, IgA and IgM molecules at site(s) different from antigen-combining site. Because of their small size and immunoglobulin (IgG)-binding activities, domains of protein A are important targets for protein engineering efforts and for the development of computational approaches for de novo protein folding.