Structures of bacterial immunoglobulin-binding domains and their complexes with immunoglobulins.

Three-dimensional structures are now available for several immunoglobulin binding domains from bacterial proteins A, G, and L. X-ray diffraction and NMR experiments on complexes of these domains with portions of immunoglobulins have revealed common structural themes used in these interactions. These data expand our understanding of structure/function relationships in these molecular recognition processes and provide the basis for rational design of artificial immunoglobulin-binding molecules.