fig4

Figure 4. Comparison of the active site structures between BiBga42A and BlGal42A. (A) Superimposition of the active sites of BiBga42A (E318S-LNT, green for protein and yellow for LNT) and BlGal42A (orange for protein and Gal); (B) Molecular surface of BiBga42A (left) and BlGal42A (right). Right, LNT in BiBga42A is superimposed as thin sticks. Surface areas of the residues contributing to shaping the different entrance sizes are colored green or orange.BiBga42A: a glycoside hydrolase family 42 β-galactosidase; LNT: lacto-N-tetraose; BlGal42A: β-1,6-1,3-galactosidase.