fig1

Figure 1. The overall structure of BiBga42A. WT-GOL structure (rainbow color) with bound glycerol (magenta) is shown. LNT in E318S-LNT structure (yellow) is superimposed [Figure 2]. (A) Monomer structure; (B) Trimer structure related by a crystallographic 3-fold axis. Trp-200 and Phe-221, which form the substrate binding site of a neighboring subunit, are indicated by arrows. BiBga42A: a glycoside hydrolase family 42 β-galactosidase; LNT: lacto-N-tetraose; WT-GOL: WT enzyme complexed with glycerol.