Glycosyl hydrolase family 43 protein such as Bacillus subtilis subsp. subtilis str. 168 endo-alpha-1,5-L-arabinanase Arb43A. This glycosyl hydrolase family 43 (GH43) subgroup belongs to the glycosyl hydrolase clan F (according to carbohydrate-active enzymes database (CAZY)) which includes family 43 (GH43) and 62 (GH62) families. GH43 are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. The GH43 ABN enzymes hydrolyze alpha-1,5-L-arabinofuranoside linkages while the ABF enzymes cleave arabinose side chains so that the combined actions of these two enzymes reduce arabinan to L-arabinose and/or arabinooligosaccharides. Many of these enzymes such as the Bacillus subtilis arabinanase Abn2, that hydrolyzes sugar beet arabinan (branched), linear alpha-1,5-L-arabinan and pectin, are different from other arabinases; they are organized into two different domains with a divalent metal cluster close to the catalytic residues to guarantee the correct protonation state of the catalytic residues and consequently the enzyme activity. These arabinan-degrading enzymes are important in the food industry for efficient production of L-arabinose from agricultural waste; L-arabinose is often used as a bioactive sweetener. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain 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 hydrolase family 43 such as arabinan endo-1 5-alpha-L-arabinosidase. This glycosyl hydrolase family 43 (GH43) subgroup includes mostly enzymes with endo-alpha-L-arabinanase (ABN; EC 3.2.1.99) activity. These are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. The GH43 ABN enzymes hydrolyze alpha-1,5-L-arabinofuranoside linkages. These arabinan-degrading enzymes are important in the food industry for efficient production of L-arabinose from agricultural waste; L-arabinose is often used as a bioactive sweetener. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain 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 hydrolase family 43 protein such as Cellvibrio japonicus Ueda107 endo-alpha-1,5-L-arabinanase / exo-alpha-1,5-L-arabinanase 43A (ArbA;CJA_0805) (Arb43A). This glycosyl hydrolase family 43 (GH43) subgroup includes mostly enzymes annotated with alpha-L-arabinofuranosidase (ABF; EC 3.2.1.55) and endo-alpha-L-arabinanase (ABN; EC 3.2.1.99) activities, and includes the bifunctional Cellvibrio japonicus Ueda107 endo-alpha-1,5-L-arabinanase / exo-alpha-1,5-L-arabinanase 43A (ArbA;CJA_0805) (Arb43A). It belongs to the glycosyl hydrolase clan F (according to carbohydrate-active enzymes database (CAZY)) which includes family 43 (GH43) and 62 (GH62) families. GH43 are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. The GH43 ABN enzymes hydrolyze alpha-1,5-L-arabinofuranoside linkages while the ABF enzymes cleave arabinose side chains so that the combined actions of these two enzymes reduce arabinan to L-arabinose and/or arabinooligosaccharides. Many of these enzymes such as the Bacillus subtilis arabinanase Abn2, that hydrolyzes sugar beet arabinan (branched), linear alpha-1,5-L-arabinan and pectin, are different from other arabinases; they are organized into two different domains with a divalent metal cluster close to the catalytic residues to guarantee the correct protonation state of the catalytic residues and consequently the enzyme activity. These arabinan-degrading enzymes are important in the food industry for efficient production of L-arabinose from agricultural waste; L-arabinose is often used as a bioactive sweetener. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain 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 hydrolase family 43 protein such as Geobacillus stearothermophilus endo-alpha-1,5-L-arabinanase AbnA. This glycosyl hydrolase family 43 (GH43) subgroup includes mostly enzymes with alpha-L-arabinofuranosidase (ABF; EC 3.2.1.55) and endo-alpha-L-arabinanase (ABN; EC 3.2.1.99) activities. It includes Geobacillus stearothermophilus T-6 NCIMB 40222 AbnA, Bacillus subtilis subsp. subtilis str. 168 (Abn2;YxiA;J3A;BSU39330) (Arb43B), and Thermotoga petrophila RKU-1 (AbnA;TpABN;Tpet_0637). These are inverting enzymes (i.e. they invert the stereochemistry of the anomeric carbon atom of the substrate) that have an aspartate as the catalytic general base, a glutamate as the catalytic general acid and another aspartate that is responsible for pKa modulation and orienting the catalytic acid. The GH43 ABN enzymes hydrolyze alpha-1,5-L-arabinofuranoside linkages while the ABF enzymes cleave arabinose side chains so that the combined actions of these two enzymes reduce arabinan to L-arabinose and/or arabinooligosaccharides. Many of these enzymes are different from other arabinases; they are organized into two different domains with a divalent metal cluster close to the catalytic residues to guarantee the correct protonation state of the catalytic residues and consequently the enzyme activity. These arabinan-degrading enzymes are important in the food industry for efficient production of L-arabinose from agricultural waste; L-arabinose is often used as a bioactive sweetener. A common structural feature of GH43 enzymes is a 5-bladed beta-propeller domain 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 43. The glycosyl hydrolase family 43 contains members that are arabinanases. Arabinanases hydrolyze the alpha-1,5-linked L-arabinofuranoside backbone of plant cell wall arabinans. The structure of arabinanase Arb43A from Cellvibrio japonicus reveals a five-bladed beta-propeller fold. A long V-shaped groove, partially enclosed at one end, forms a single extended substrate-binding surface across the face of the propeller.

Structureof the thermostable arabinanase [Geobacillus thermodenitrificans]

Highresolution crystal structure of 1,5-alpha-L-arabinanase from Geobacillus Stearothermophilus [Geobacillus stearothermophilus]

Crystalstructure of endo-arabinanase ABN-TS D147N mutant in complex with arabinohexaose [Geobacillus thermodenitrificans],6A8I_B Crystal structure of endo-arabinanase ABN-TS D147N mutant in complex with arabinohexaose [Geobacillus thermodenitrificans]

ChainA, Intracellular arabinanase [Geobacillus stearothermophilus],3D5Z_A Chain A, Intracellular arabinanase [Geobacillus stearothermophilus]

Thestructure of AbnB-E201A, an intracellular 1,5-alpha-L-arabinanase from Geobacillus stearothermophilus, in complex with arabinopentaose [Geobacillus stearothermophilus]

Intracellular endo-alpha-(1->5)-L-arabinanase OS=Geobacillus thermodenitrificans OX=33940 GN=abn-ts PE=1 SV=1

Intracellular endo-alpha-(1->5)-L-arabinanase OS=Geobacillus stearothermophilus OX=1422 GN=abnB PE=1 SV=1

Extracellular endo-alpha-(1->5)-L-arabinanase OS=Thermotoga petrophila (strain ATCC BAA-488 / DSM 13995 / JCM 10881 / RKU-1) OX=390874 GN=Tpet_0637 PE=1 SV=1

Extracellular endo-alpha-(1->5)-L-arabinanase 2 OS=Bacillus subtilis (strain 168) OX=224308 GN=abn2 PE=1 SV=2

Extracellular endo-alpha-(1->5)-L-arabinanase 1 OS=Bacillus subtilis (strain 168) OX=224308 GN=abnA PE=1 SV=3