Hypothetical glycosyl hydrolase 6. GHL6 is a family of hypothetical glycoside hydrolases.

A4 beta-galactosidase middle domain: a type 1 glutamine amidotransferase (GATase1)-like domain. A4 beta-galactosidase middle domain: a type 1 glutamine amidotransferase (GATase1)-like domain. This group includes proteins similar to beta-galactosidase from Thermus thermophilus. Beta-Galactosidase hydrolyzes the beta-1,4-D-galactosidic linkage of lactose, as well as those of related chromogens, o-nitrophenyl-beta-D-galactopyranoside (ONP-Gal) and 5-bromo-4-chloro-3-indolyl-beta-D-galactoside (X-gal). This A4 beta-galactosidase middle domain lacks the catalytic triad of typical GATase1 domains. The reactive Cys residue found in the sharp turn between a beta strand and an alpha helix termed the nucleophile elbow in typical GATase1 domains is not conserved in this group.

Beta-galactosidase GanA [Carbohydrate transport and metabolism].

Beta-galactosidase trimerisation domain. This is non catalytic domain B of beta-galactosidase enzymes belong to the glycosyl hydrolase 42 family. This domain is related to glutamine amidotransferase enzymes, but the catalytic residues are replaced by non functional amino acids. This domain is involved in trimerisation.

Glycoside Hydrolase Family 66. Glycoside Hydrolase Family 66 contains proteins characterized as cycloisomaltooligosaccharide glucanotransferase (CITase) and dextranases from a variety of bacteria. CITase cyclizes part of a (1-6)-alpha-D-glucan (dextrans) chain by formation of a (1-6)-alpha-D-glucosidic bond. Dextranases catalyze the endohydrolysis of (1-6)-alpha-D-glucosidic linkages in dextran. Some members contain Carbohydrate Binding Module 35 (CBM35) domains, either C-terminal or inserted in the domain or both.

ChainAAA, Alpha-L-fucosidase [Paenibacillus thiaminolyticus]