The basic lectin from Artocarpus hirsuta specific towards methyl α-galactose has been purified and crystallized using the hanging-drop vapour-diffusion method with ammonium sulfate as precipitant. Three different crystal forms, orthorhombic I, orthorhombic II and hexagonal, were grown under the same crystallization conditions. The orthorhombic forms belonged to space group P212121 with unit-cell dimensions a = 92.9, b = 99.8, c = 166.2 Å and a = 89.9, b = 121.9, c = 131.6 Å, respectively. The unit-cell dimensions of the hexagonal form were a = b = 84.1 and c = 271.7 Å and the space group was P6122.
