Glycosyl hydrolase family 43 protein most having a F5/8 type C domain C-terminal to the GH43 domain. This glycosyl hydrolase family 43 (GH43) subgroup includes enzymes that have been annotated as having beta-xylosidase (EC 3.2.1.37), xylanase (EC 3.2.1.8), and beta-galactosidase (EC 3.2.1.145) activities, and some as F5/8 type C domain (also known as the discoidin (DS) domain)-containing proteins. Most contain a F5/8 type C domain C-terminal to the GH43 domain. 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. Many GH43 enzymes display both alpha-L-arabinofuranosidase and beta-D-xylosidase activity using aryl-glycosides as substrates. Characterized enzymes belonging to this subgroup include Lactobacillus brevis (LbAraf43) and Weissella sp (WAraf43) which show activity with similar catalytic efficiency on 1,5-alpha-L-arabinooligosaccharides with a degree of polymerization (DP) of 2-3; size is limited by an extended loop at the entrance to the active site. 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 Bacteroides thetaiotaomicron VPI-5482 alpha-L-arabinofuranosidases (BT3675;BT_3675) and (BT3662;BT_3662); includes mostly xylanases. This glycosyl hydrolase family 43 (GH43) subgroup includes enzymes that have been annotated as xylan-digesting beta-xylosidase (EC 3.2.1.37) and xylanase (endo-alpha-L-arabinanase, EC 3.2.1.8) activities, as well the Bacteroides thetaiotaomicron VPI-5482 alpha-L-arabinofuranosidases (EC 3.2.1.55) (BT3675;BT_3675) and (BT3662;BT_3662). 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. 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.

Carbohydrate Binding Module 6 (CBM6); many are appended to glycoside hydrolase (GH) family 11 and GH43 xylanase domains. This family includes carbohydrate binding module 6 (CBM6) domains that are appended mainly to glycoside hydrolase (GH) family domains, including GH3, GH11, and GH43 domains. These CBM6s are non-catalytic carbohydrate binding domains that facilitate the strong binding of the GH catalytic modules with their dedicated, insoluble substrates. Examples of proteins having CMB6s belonging to this family are Microbispora bispora GghA, a 1,4-beta-D-glucan glucohydrolase (GH3); Clostridium thermocellum xylanase U (GH11), and Penicillium purpurogenum ABF3, a bifunctional alpha-L-arabinofuranosidase/xylobiohydrolase (GH43). GH3 comprises enzymes with activities including beta-glucosidase (hydrolyzes beta-galactosidase) and beta-xylosidase (hydrolyzes 1,4-beta-D-xylosidase). GH11 family comprises enzymes with xylanase (endo-1,4-beta-xylanase) activity which catalyze the hydrolysis of beta-1,4 bonds of xylan, the major component of hemicelluloses, to generate xylooligosaccharides and xylose. GH43 includes beta-xylosidases and beta-xylanases, using aryl-glycosides as substrates. CBM6 is an unusual CBM as it represents a chimera of two distinct binding sites with different modes of binding: binding site I within the loop regions and binding site II on the concave face of the beta-sandwich fold.

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 Aspergillus niger DMS1957 xylanase D (XlnD); includes mostly xylanases. This glycosyl hydrolase family 43 (GH43) subgroup includes enzymes that have mostly been annotated as xylanases (endo-alpha-L-arabinanase, EC 3.2.1.8). It belongs to the GH43_bXyl-like subgroup of the glycosyl hydrolase clan F (according to carbohydrate-active enzymes database (CAZY)) which includes family 43 (GH43) and 62 (GH62) families. The GH43_bXyl-like subgroup includes enzymes that have been annotated as xylan-digesting beta-xylosidases (EC 3.2.1.37) and xylanases, as well the Bacteroides thetaiotaomicron VPI-5482 alpha-L-arabinofuranosidases (EC 3.2.1.55) (BT3675;BT_3675) and (BT3662;BT_3662). 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.

Glycosidehydrolase BT_3662 [Bacteroides thetaiotaomicron VPI-5482],5MSX_B Glycoside hydrolase BT_3662 [Bacteroides thetaiotaomicron VPI-5482],5MSX_C Glycoside hydrolase BT_3662 [Bacteroides thetaiotaomicron VPI-5482]

Crystalstructure of an Endo-1,4-beta-xylanase D (BT_3675) from Bacteroides thetaiotaomicron VPI-5482 at 1.74 A resolution [Bacteroides thetaiotaomicron],3QZ4_B Crystal structure of an Endo-1,4-beta-xylanase D (BT_3675) from Bacteroides thetaiotaomicron VPI-5482 at 1.74 A resolution [Bacteroides thetaiotaomicron]

CrystalStructure of a Family 6 Carbohydrate-Binding Module from Clostridium cellulolyticum in complex with xylose [Ruminiclostridium cellulolyticum]

ChainA, S-layer domain-containing protein [Acetivibrio thermocellus ATCC 27405]

Crystalstructure of a glycoside hydrolase family 43 arabinoxylan arabinofuranohydrolase from Bacillus subtilis. [Bacillus subtilis],3C7F_A Crystal structure of a glycoside hydrolase family 43 arabinoxylan arabinofuranohydrolase from bacillus subtilis in complex with xylotriose. [Bacillus subtilis],3C7H_A Crystal structure of glycoside hydrolase family 43 arabinoxylan arabinofuranohydrolase from Bacillus subtilis in complex with AXOS-4-0.5. [Bacillus subtilis],3C7O_A Crystal structure of a glycoside hydrolase family 43 arabinoxylan arabinofuranohydrolase from Bacillus subtilis in complex with cellotetraose. [Bacillus subtilis]

Arabinoxylan arabinofuranohydrolase OS=Bacillus subtilis (strain 168) OX=224308 GN=xynD PE=1 SV=2

Endo-1,4-beta-xylanase Z OS=Acetivibrio thermocellus (strain ATCC 27405 / DSM 1237 / JCM 9322 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372) OX=203119 GN=xynZ PE=1 SV=3

Endo-1,4-beta-xylanase A OS=Thermoclostridium stercorarium OX=1510 GN=xynA PE=1 SV=2

Endo-1,4-beta-xylanase A OS=Thermoclostridium stercorarium OX=1510 GN=xynA PE=1 SV=2