glycoside hydrolase family 32 protein such as Aspergillus ficuum endo-inulinase (Inu2). This subfamily of glycosyl hydrolase family GH32 includes endo-inulinase (inu2, EC 3.2.1.7), exo-inulinase (Inu1, EC 3.2.1.80), invertase (EC 3.2.1.26), and levan fructotransferase (LftA, EC 4.2.2.16), among others. These enzymes cleave sucrose into fructose and glucose via beta-fructofuranosidase activity, producing invert sugar that is a mixture of dextrorotatory D-glucose and levorotatory D-fructose, thus named invertase (EC 3.2.1.26). These retaining enzymes (i.e. they retain the configuration at anomeric carbon atom of the substrate) catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate: an aspartate located close to the N-terminus acts as the catalytic nucleophile and a glutamate acts as the general acid/base; a conserved aspartate residue in the Arg-Asp-Pro (RDP) motif stabilizes the transition state. These enzymes are predicted to display a 5-fold beta-propeller fold as found for GH43 and CH68. The breakdown of sucrose is widely used as a carbon or energy source by bacteria, fungi, and plants. Invertase is used commercially in the confectionery industry, since fructose has a sweeter taste than sucrose and a lower tendency to crystallize. A common structural feature of all these enzymes is a 5-bladed beta-propeller domain, similar to GH43, that contains the catalytic acid and catalytic base. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.

Glycosyl hydrolases family 32.

Glycosyl hydrolases family 32 N-terminal domain. This domain corresponds to the N-terminal domain of glycosyl hydrolase family 32 which forms a five bladed beta propeller structure.

Sucrose-6-phosphate hydrolase SacC, GH32 family [Carbohydrate transport and metabolism].

Glycosyl hydrolase family 32, beta-fructosidases. Glycosyl hydrolase family GH32 cleaves sucrose into fructose and glucose via beta-fructofuranosidase activity, producing invert sugar that is a mixture of dextrorotatory D-glucose and levorotatory D-fructose, thus named invertase (EC 3.2.1.26). This family also contains other fructofuranosidases such as inulinase (EC 3.2.1.7), exo-inulinase (EC 3.2.1.80), levanase (EC 3.2.1.65), and transfructosidases such sucrose:sucrose 1-fructosyltransferase (EC 2.4.1.99), fructan:fructan 1-fructosyltransferase (EC 2.4.1.100), sucrose:fructan 6-fructosyltransferase (EC 2.4.1.10), fructan:fructan 6G-fructosyltransferase (EC 2.4.1.243) and levan fructosyltransferases (EC 2.4.1.-). These retaining enzymes (i.e. they retain the configuration at anomeric carbon atom of the substrate) catalyze hydrolysis in two steps involving a covalent glycosyl enzyme intermediate: an aspartate located close to the N-terminus acts as the catalytic nucleophile and a glutamate acts as the general acid/base; a conserved aspartate residue in the Arg-Asp-Pro (RDP) motif stabilizes the transition state. These enzymes are predicted to display a 5-fold beta-propeller fold as found for GH43 and CH68. The breakdown of sucrose is widely used as a carbon or energy source by bacteria, fungi, and plants. Invertase is used commercially in the confectionery industry, since fructose has a sweeter taste than sucrose and a lower tendency to crystallize. A common structural feature of all these enzymes is a 5-bladed beta-propeller domain, similar to GH43, that contains the catalytic acid and catalytic base. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.

Firstcrystal structure of an endo-inulinase, from Aspergillus ficuum: structural analysis and comparison with other GH32 enzymes. [Aspergillus ficuum],3SC7_X First crystal structure of an endo-inulinase, from Aspergillus ficuum: structural analysis and comparison with other GH32 enzymes. [Aspergillus ficuum]

Crystalstructure of exo-inulinase from Aspergillus awamori in spacegroup P21 [Aspergillus awamori],1Y9G_A Crystal structure of exo-inulinase from Aspergillus awamori complexed with fructose [Aspergillus awamori],1Y9M_A Crystal structure of exo-inulinase from Aspergillus awamori in spacegroup P212121 [Aspergillus awamori]

ChainA, Invertase [Schwanniomyces occidentalis],3KF3_B Chain B, Invertase [Schwanniomyces occidentalis]

ChainA, Invertase [Schwanniomyces occidentalis],3KF5_B Chain B, Invertase [Schwanniomyces occidentalis]

ChainA, Fructofuranosidase [Schwanniomyces occidentalis],3U75_B Chain B, Fructofuranosidase [Schwanniomyces occidentalis],3U75_C Chain C, Fructofuranosidase [Schwanniomyces occidentalis],3U75_D Chain D, Fructofuranosidase [Schwanniomyces occidentalis]

Levanase OS=Bacillus subtilis (strain 168) OX=224308 GN=sacC PE=1 SV=1

Invertase OS=Schizosaccharomyces pombe (strain 972 / ATCC 24843) OX=284812 GN=inv1 PE=1 SV=1

Extracellular endo-inulinase inuA OS=Aspergillus niger (strain CBS 513.88 / FGSC A1513) OX=425011 GN=inuA PE=1 SV=1

Extracellular endo-inulinase inu2 OS=Aspergillus ficuum OX=5058 GN=inu2 PE=1 SV=1

Extracellular endo-inulinase inuA OS=Aspergillus niger OX=5061 GN=inuA PE=1 SV=1