beta-N-acetylglucosaminidase. This family has previously been described as a hyaluronidase. However, more recently it has been shown that this family has beta-N-acetylglucosaminidase activity.

Glycosyl hydrolase family 20 (GH20) catalytic domain of dispersin B (DspB), lacto-N-biosidase (LnbB) and related proteins. Dispersin B is a soluble beta-N-acetylglucosamidase found in bacteria that hydrolyzes the beta-1,6-linkages of PGA (poly-beta-(1,6)-N-acetylglucosamine), a major component of the extracellular polysaccharide matrix. Lacto-N-biosidase hydrolyzes lacto-N-biose (LNB) type I oligosaccharides at the nonreducing terminus to produce lacto-N-biose as part of the GNB/LNB (galacto-N-biose/lacto-N-biose I) degradation pathway. The lacto-N-biosidase from Bifidobacterium bifidum has this GH20 domain, a carbohydrate binding module 32, and a bacterial immunoglobulin-like domain 2, as well as a YSIRK signal peptide and a G5 membrane anchor at the N and C termini, respectively. The GH20 hexosaminidases are thought to act via a catalytic mechanism in which the catalytic nucleophile is not provided by solvent or the enzyme, but by the substrate itself.

Beta-N-acetylhexosaminidases of glycosyl hydrolase family 20 (GH20) catalyze the removal of beta-1,4-linked N-acetyl-D-hexosamine residues from the non-reducing ends of N-acetyl-beta-D-hexosaminides including N-acetylglucosides and N-acetylgalactosides. These enzymes are broadly distributed in microorganisms, plants and animals, and play roles in various key physiological and pathological processes. These processes include cell structural integrity, energy storage, cellular signaling, fertilization, pathogen defense, viral penetration, the development of carcinomas, inflammatory events and lysosomal storage disorders. The GH20 enzymes include the eukaryotic beta-N-acetylhexosaminidases A and B, the bacterial chitobiases, dispersin B, and lacto-N-biosidase. The GH20 hexosaminidases are thought to act via a catalytic mechanism in which the catalytic nucleophile is not provided by the solvent or the enzyme, but by the substrate itself.

Glycosyl hydrolase family 20, catalytic domain. This domain has a TIM barrel fold.

N-acetyl-beta-hexosaminidase [Carbohydrate transport and metabolism].

Structureof CpGH84A [Clostridium perfringens ATCC 13124],6PV4_B Structure of CpGH84A [Clostridium perfringens ATCC 13124],6PV4_C Structure of CpGH84A [Clostridium perfringens ATCC 13124],6PV4_D Structure of CpGH84A [Clostridium perfringens ATCC 13124]

Structureof CpGH84D [Clostridium perfringens ATCC 13124],6PWI_B Structure of CpGH84D [Clostridium perfringens ATCC 13124]

Crystallizationanalysis of a beta-N-acetylhexosaminidase (Am2136) from Akkermansia muciniphila [Akkermansia muciniphila ATCC BAA-835]

Structureof CpGH84B [Clostridium perfringens ATCC 13124]

Structureof a Family 84 Glycoside Hydrolase and a Family 32 Carbohydrate-Binding Module in Tandem from Clostridium perfringens. [Clostridium perfringens]

Hyaluronoglucosaminidase OS=Clostridium perfringens (strain 13 / Type A) OX=195102 GN=nagH PE=1 SV=2

Beta-hexosaminidase Amuc_2136 OS=Akkermansia muciniphila (strain ATCC BAA-835 / DSM 22959 / JCM 33894 / BCRC 81048 / CCUG 64013 / CIP 107961 / Muc) OX=349741 GN=Amuc_2136 PE=1 SV=1

O-GlcNAcase NagJ OS=Clostridium perfringens (strain ATCC 13124 / DSM 756 / JCM 1290 / NCIMB 6125 / NCTC 8237 / Type A) OX=195103 GN=nagJ PE=1 SV=1

O-GlcNAcase NagJ OS=Clostridium perfringens (strain 13 / Type A) OX=195102 GN=nagJ PE=1 SV=1

O-GlcNAcase BT_4395 OS=Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50) OX=226186 GN=BT_4395 PE=1 SV=1