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 Halothermothrix orenii H 168 alpha-L-arabinofuranosidase (HoAraf43;Hore_20580). This glycosyl hydrolase family 43 (GH43) subgroup includes Halothermothrix orenii H 168 alpha-L-arabinofuranosidase (EC 3.2.1.55) (HoAraf43;Hore_20580). It belongs to the glycosyl hydrolase clan F (according to carbohydrate-active enzymes database (CAZY)) which includes family 43 (GH43) and 62 (GH62) families. This GH43_ HoAraf43-like subgroup includes enzymes that have been annotated as having xylan-digesting beta-xylosidase (EC 3.2.1.37) and xylanase (endo-alpha-L-arabinanase, EC 3.2.1.8) activities. 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. Many GH43 enzymes display both alpha-L-arabinofuranosidase and beta-D-xylosidase activity using aryl-glycosides as substrates. 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 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 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 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.

Crystalstructure of Endo-1,4-beta-xylanase (NP_811807.1) from BACTEROIDES THETAIOTAOMICRON VPI-5482 at 1.70 A resolution [Bacteroides thetaiotaomicron VPI-5482],3KST_B Crystal structure of Endo-1,4-beta-xylanase (NP_811807.1) from BACTEROIDES THETAIOTAOMICRON VPI-5482 at 1.70 A resolution [Bacteroides thetaiotaomicron VPI-5482]

Crystalstructure of a thermostable family-43 glycoside hydrolase [Halothermothrix orenii H 168],4QQS_B Crystal structure of a thermostable family-43 glycoside hydrolase [Halothermothrix orenii H 168]

Structureof Cellvibrio cellulosa alpha-L-arabinanase [Cellvibrio japonicus]

Structureof D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus],1GYH_B Structure of D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus],1GYH_C Structure of D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus],1GYH_D Structure of D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus],1GYH_E Structure of D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus],1GYH_F Structure of D158A Cellvibrio cellulosa alpha-L-arabinanase mutant [Cellvibrio japonicus]

Structureof Cellvibrio cellulosa alpha-L-arabinanase complexed with Arabinohexaose [Cellvibrio japonicus]

Extracellular exo-alpha-(1->5)-L-arabinofuranosidase ArbA OS=Cellvibrio japonicus (strain Ueda107) OX=498211 GN=arbA PE=1 SV=1

Probable arabinan endo-1,5-alpha-L-arabinosidase A OS=Aspergillus flavus (strain ATCC 200026 / FGSC A1120 / IAM 13836 / NRRL 3357 / JCM 12722 / SRRC 167) OX=332952 GN=abnA PE=3 SV=1

Probable arabinan endo-1,5-alpha-L-arabinosidase A OS=Aspergillus oryzae (strain ATCC 42149 / RIB 40) OX=510516 GN=abnA PE=3 SV=1

Probable arabinan endo-1,5-alpha-L-arabinosidase A OS=Aspergillus niger (strain CBS 513.88 / FGSC A1513) OX=425011 GN=abnA PE=3 SV=1

Arabinan endo-1,5-alpha-L-arabinosidase A OS=Aspergillus niger OX=5061 GN=abnA PE=1 SV=1