Bacterial alpha-L-rhamnosidase 6 hairpin glycosidase domain. This family consists of bacterial rhamnosidase A and B enzymes. L-Rhamnose is abundant in biomass as a common constituent of glycolipids and glycosides, such as plant pigments, pectic polysaccharides, gums or biosurfactants. Some rhamnosides are important bioactive compounds. For example, terpenyl glycosides, the glycosidic precursor of aromatic terpenoids, act as important flavouring substances in grapes. Other rhamnosides act as cytotoxic rhamnosylated terpenoids, as signal substances in plants or play a role in the antigenicity of pathogenic bacteria.

Glycosyl-hydrolase family 116, catalytic region. This represents a family of archaeal, bacterial and eukaryotic glycosyl hydrolases, that belong to superfamily GH116. The primary catabolic pathway for glucosylceramide is catalysis by the lysosomal enzyme glucocerebrosidase. In higher eukaryotes, glucosylceramide is the precursor of glycosphingolipids, a complex group of ubiquitous membrane lipids. Mutations in the human protein cause motor-neurone defects in hereditary spastic paraplegia. The catalytic nucleophile, identified in UniProtKB:Q97YG8_SULSO, is a glutamine-335, with the likely acid/base at Asp-442 and the aspartates at Asp-406 and Asp-458 residues also playing a role in the catalysis of glucosides and xylosides that are beta-bound to hydrophobic groups. The family is defined as GH116, which presently includes enzymes with beta-glucosidase, EC:3.2.1.21, beta-xylosidase, EC:3.2.1.37, and glucocerebrosidase EC:3.2.1.45 activity.

Bacterial alpha-L-rhamnosidase C-terminal domain. This family consists of bacterial rhamnosidase A and B enzymes. L-Rhamnose is abundant in biomass as a common constituent of glycolipids and glycosides, such as plant pigments, pectic polysaccharides, gums or biosurfactants. Some rhamnosides are important bioactive compounds. For example, terpenyl glycosides, the glycosidic precursor of aromatic terpenoids, act as important flavouring substances in grapes. Other rhamnosides act as cytotoxic rhamnosylated terpenoids, as signal substances in plants or play a role in the antigenicity of pathogenic bacteria.

Glycosyl hydrolase 36 superfamily, catalytic domain. This is the catalytic region of the superfamily of enzymes referred to as GH36. UniProtKB:Q76IQ9 is a chitobiose phosphorylase that catalyzes the reversible phosphorolysis of chitobiose into alpha-GlcNAc-1-phosphate and GlcNAc with inversion of the anomeric configuration. The full-length enzyme comprises a beta sandwich domain and an (alpha/alpha)(6) barrel domain. The alpha-helical barrel component of the domain, this family, is the catalytic region.

Crystalstructure of GH78 family rhamnosidase of Bacillus SP. GL1 AT 1.9 A [Bacillus sp. GL1],2OKX_B Crystal structure of GH78 family rhamnosidase of Bacillus SP. GL1 AT 1.9 A [Bacillus sp. GL1]