The three-dimensional structure of recombinant human α-galactosidase. (a) Monomer showing two domains with an N-terminal (blue) and C-terminal (red). Galactose, with red and yellow atoms, is shown in the active site. β, beta strands;α, alpha helix. (b and c) Two views of the dimer. (d) Filled view of the model showing N-linked glycans in green. Degree of rotation of molecules is indicated. Reproduced with permission from [24].