New structural insights into lectin-type proteins of the immune system

New structural data have emerged for the ligand-binding sites of C-type lec tin domains and C-type lectin-like domains of receptors of the immune syste m. These include binding sites for oligosaccharide or polypeptide ligands, or both oligosaccharide and polypeptide ligands. The structural basis for t he binding of a lectin domain of the beta -trefoil family to different sulf o-oligosaccharide sequences has been revealed. Lectin activity has been doc umented for a beta/alpha, TIM barrel fold that does not have the chitinase activity of the prototype enzyme with this fold.