Glycoside hydrolase 97. This domain is the catalytic region of the bacterial glycosyl-hydrolase family 97. This central part of the GH97 family protein sequences represents a typical and complete (beta/alpha)8-barrel or catalytic TIM-barrel type domain. The N- and C-terminal parts of the sequences, mainly consisting of beta-strands, form two additional non-catalytic domains. In all known glycosidases with the (beta-alpha)8-barrel fold, the amino acid residues at the active site are located on the C-termini of the beta-strands.

Glycosyl-hydrolase 97 N-terminal. This N-terminal domain of glycosyl-hydrolase-97 contributes part of the active site pocket. It is also important for contact with the catalytic and C-terminal domains of the whole.

Glycosyl-hydrolase 97 C-terminal, oligomerization. Glycosyl-hydrolase-97 is made up of three tightly linked and highly conserved globular domains. The C-terminal domain is found to be necessary for oligomerization of the whole molecule in order to create the active-site pocket and the Ca++-binding site.

The chitobiase of Serratia marcescens is a beta-N-1,4-acetylhexosaminidase with a glycosyl hydrolase family 20 (GH20) domain that hydrolyzes the beta-1,4-glycosidic linkages in oligomers derived from chitin. Chitin is degraded by a two step process: i) a chitinase hydrolyzes the chitin to oligosaccharides and disaccharides such as di-N-acetyl-D-glucosamine and chitobiose, ii) chitobiase then further degrades these oligomers into monomers. This GH20 domain family includes an N-acetylglucosamidase (GlcNAcase A) from Pseudoalteromonas piscicida and an N-acetylhexosaminidase (SpHex) from Streptomyces plicatus. SpHex lacks the C-terminal PKD (polycystic kidney disease I)-like domain found in the chitobiases. 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.

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

AGlycoside Hydrolase Family 97 enzyme from Pseudoalteromonas sp. strain K8 [Pseudoalteromonas sp. K8],5HQA_A A Glycoside Hydrolase Family 97 enzyme in complex with Acarbose from Pseudoalteromonas sp. strain K8 [Pseudoalteromonas sp. K8]

AGlycoside Hydrolase Family 97 enzyme R171K variant from Pseudoalteromonas sp. strain K8 [Pseudoalteromonas sp. K8]

AGlycoside Hydrolase Family 97 enzyme (E480Q) in complex with Panose from Pseudoalteromonas sp. strain K8 [Pseudoalteromonas sp. K8]

Catalyticrole of the calcium ion in GH97 inverting glycoside hydrolase [Bacteroides thetaiotaomicron],3WFA_B Catalytic role of the calcium ion in GH97 inverting glycoside hydrolase [Bacteroides thetaiotaomicron]

Nativestructure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482],2JKA_B Native structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron [Bacteroides thetaiotaomicron VPI-5482],2JKE_A Structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron in complex with deoxynojirimycin [Bacteroides thetaiotaomicron VPI-5482],2JKE_B Structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron in complex with deoxynojirimycin [Bacteroides thetaiotaomicron VPI-5482],2JKP_A Structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron in complex with castanospermine [Bacteroides thetaiotaomicron VPI-5482],2JKP_B Structure of a family 97 alpha-glucosidase from Bacteroides thetaiotaomicron in complex with castanospermine [Bacteroides thetaiotaomicron VPI-5482]

Glucan 1,4-alpha-glucosidase SusB OS=Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50) OX=226186 GN=susB PE=1 SV=1

Retaining alpha-galactosidase OS=Bacteroides thetaiotaomicron (strain ATCC 29148 / DSM 2079 / JCM 5827 / CCUG 10774 / NCTC 10582 / VPI-5482 / E50) OX=226186 GN=BT_1871 PE=1 SV=1

Probable retaining alpha-galactosidase OS=Streptomyces bingchenggensis (strain BCW-1) OX=749414 GN=SBI_01652 PE=3 SV=1