STRUCTURE OF THE COLLAGEN-BINDING DOMAIN FROM A STAPHYLOCOCCUS-AUREUSADHESIN

The crystal structure of the recombinant 19,000 M-r binding domain fro m the Staphylococcus aureus collagen adhesin has been determined at 2 Angstrom resolution. The domain fold Is a jelly-roll, composed of two antiparallel beta-sheets and two short alpha-helices. Triple-helical c ollagen model probes were used in a systematic docking search to ident ify the collagen-binding site. A groove on beta-sheet I exhibited the best surface complementarity to the collagen probes. This site partial ly overlaps with the peptide sequence previously shown to be critical for collagen binding. Recombinant proteins containing single amino aci d mutations designed to disrupt the surface of the putative binding si te exhibited significantly lower affinities for collagen. Here we pres ent a structural perspective for the mode of collagen binding by a bac terial surface protein.