Figure 2

Portion of the multiple sequence alignment of the sequences analyzed. Ten-letter name for each sequence is indicated in the leftmost column (for origin of the sequences see Table I). The alignment continuously spans three panels. Distances to the N- and C-termini and length of omitted fragments are indicated. Highly conserved residues are highlighted in sequences. Amino acid positions that are highly conserved within several subfamilies but varied in amino acid residues in different subfamilies are coloured. Subfamily belonging of sequences (for family GH97) are indicated in the most right. Amino acid residues, interacting with the substrate in the active center of GH27 and GH31 family glycosidases, are indicated by arrows at the bottom [50-54]. The arrow on the gray background corresponds to the Asp residue, playing the role of the nucleophile in glycosidases of families GH27 and GH31. Red asterisks over and under the alignment indicate three conserved positions (in red) probably corresponding to the nucleophile and proton donor in the glycosidases of family GH97 (see text). Alignment of GH27_ORYSA and GH31_ECOLI is structure-based. At the bottom of the figure, β-strands and α-helixes of the (β/α)₈-barrel are indicated. The first part of the barrel (β1–β4) is shown according to the known structures of GH27 and GH31 family members [51, 54]. The second part of the barrel (α4–α8) is based on generalization of predictions for several GH97 family proteins by 3D-PSSM, GOR IV, and nnpredict programs.