The crystal structure of AOL (a fucose-specific lectin of Aspergillus oryzae) has been solved by SAD (single wavelength anomalous diffraction) and MAD (multi-wavelength anomalous diffraction) phasing of seleno-fucosides. The overall structure is a six-bladed beta-propeller similar to that of other fucose-specific lectins. The fucose moieties of the seleno-fucosides are located in six fucose-binding sites. Although the Arg and Glu/GIn residues bound to the fucose moiety are common to all fucose-binding sites, the amino acid residues involved in fucose binding at each site are not identical. The varying peak heights of the seleniums in the electron density map suggest that each fucose-binding site has a different carbohydrate binding affinity. (C) 2016 The Authors. Published by Elsevier Inc.