Fig. 1

The common 3D structure of high symmetric β-trefoil fold protein. a 3D structure of galactose-binding lectin (PDB ID: 2RST). The number of residues is 132. The three β-trefoil units are colored in red, green, and blue, respectively, from the N- to C-termini. b Schematic drawing of β-trefoil topology. β-strands colored in orange and green form a barrel and the cap structures, respectively