We used a blastp search for the amino acid sequence of IPO [GenBank: BAA14024.1] against the algorithm of the National Center for Biotechnology Information (NCBI) protein databank database for searching structural templates. The amino acid sequence of Calystegia sepium agglutinin (Calsepa), a JRL (PDB: 1OUW), showed 53% sequence identity to that of IPO. The monomeric structure of Calsepa was further used in a search to determine the structure of apo IPO by molecular replacement with use of the program CNS [39] . After cross-rotation and translation of molecular replacement, 4 values were obtained. Initial rigid body refinement for the 4 monomeric structures gave a 48.8% R-factor. Clear continuous electron density could be observed after calculation of Fourier maps, and the 5 th molecule of apo IPO was further built accordingly. Because of different space groups for the structures of the IPO-Me-Man, IPO-Me-Glc and IPO-Me-Gal complexes, the resolved monomeric apo IPO was used as a search template in the following molecular replacement method. The solutions of cross-rotation and translation could be obtained with 2 molecules for the IPO-Me-Man complex, 4 molecules for IPO-Me-Glc and 4 molecules for IPO-Me-Gal. Those solutions were further applied to initial rigid body refinement, and reasonable values were obtained (e.g., 36 .7% Rfactor for IPO-Me-Man, 35.4% for IPO-Me-Glc, and 32.9% for IPO-Me-Gal).