Table 3.
Amino acid residues at positions involved in hydrogen bonds with β-fructofuranose in B.longum-GH32 and L.gasseri-GH32
| B.longum-GH32* | L.gasseri-GH32** | Cluster 1 (n = 6) |
Cluster 2 (n = 5) |
Cluster 3 (n = 3) |
Cluster 4 (N = 3) |
|
|---|---|---|---|---|---|---|
| Asn53 | Asn46 | Asn | Asn | Asn | Gly | NDPNG motif Catalytic triad, NDPNG motif |
| Asp54 | Asp47 | Asp | Asp | Asp | Asp | |
| Gln70 | Gln63 | Gln | Gln | Gln | Gln, Leu | |
| Trp78 | (His71)*** | Trp | Gly, His | Trp | Gly, Ala, Arg | |
| (Met81)*** | Lys74 | Met | Lys | Met, Leu | Thr, Phe | |
| Ser114 | Ser107 | Ser | Ser | Thr, Ala | Ser |
RDP motif Catalytic triad, RDP motif Catalytic triad, ECP motif |
| Arg180 | Arg166 | Arg | Arg | Arg | Arg | |
| Asp181 | Asp167 | Asp | Asp | Asp | Asp | |
| Glu235 | Glu222 | Glu | Glu | Glu | Glu |
Amino acids identical with those of the two reference enzymes are written in bold. Clusters 1 to 4 correspond to clusters shown in Fig. 5.
*Eight amino acid residues involved in hydrogen bonds with β-fructofuranose in B.longum-GH32
**Eight amino acid residues involved in hydrogen bonds with β-fructofuranose in L.gasseri-GH32
***(Met81) in B.longum-GH32 and (His71) in L.gasseri-GH32 are not involved in forming a hydrogen bond with β-fructofuranose but are equivalent loci to Lys74 in L.gasseri-GH32 and Trp78 in B.longum-GH32, respectively