Structures of a human blood group glycosyltransferase in complex with a photo-activatable UDP-Gal derivative reveal two different binding conformations

The structure of AA(Gly)B, a dual-specificity blood group synthase, in complex with UDP-galactose, the O6'' atom of which is protected by an 2-nitrobenzyl group, has been determined in two space groups. The so-called caged substrate exhibits various distinct conformations in the active site.