Figure 5.

Schematic representation of the hydrogen-bond networks between loops β2–β3, β5–β6, β7–β8 and β9–β10 in wild-type Fbs1 SBD (a), loop-mutant 1 (b) and FBG3 (c). The four loops β2–β3, β5–β6, β7–β8 and β9–β10 are indicated in blue, cyan, magenta and yellow, respectively. The hydrogen bonds between each loop are indicated with red lines. The residues of the carbohydrate-binding pocket of wild-type Fbs1 SBD and the corresponding residues of loop-mutant 1 and the FBG3 SBD are underlined. The corresponding residues, based on sequence alignments of wild-type Fbs1 SBD and loop-mutant 1 or of Fbs1 SBD loop-mutant 1 and the SBD of FBG3, are located in the relative positions and are marked with asterisks.