FIGURE 5.

Structural similarity with GH42 thermophilic β-galactosidase. A, superimposition of TIM barrel domains of GLNBP (yellow) and A4-β-galactosidase (black). B, close-up view of A at the active site. Bound ligands and catalytically important residues in both structures are shown in ball-and-stick and wire frame models, respectively.