UniProt functional annotation for A3DIH0



	UniProt functional annotation for A3DIH0

UniProt code: A3DIH0.

Organism: Hungateiclostridium thermocellum (strain ATCC 27405 / DSM 1237 / JCM 9322 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372) (Clostridium thermocellum).

Taxonomy: Bacteria; Firmicutes; Clostridia; Eubacteriales; Oscillospiraceae; Acetivibrio.

Function: Involved in the degradation of arabinan and is a key enzyme in the complete degradation of the plant cell wall. Catalyzes the cleavage of terminal alpha-(1->5)-arabinofuranosyl bonds in small oligosaccharides as alpha-(1->5)-linked arabinobiose/arabinotriose, but does not display significant activity against linear non-substituted arabinan. It is also highly efficient in the cleavage of alpha-(1->3)- linked arabinoside of xylobiose and of the alpha-(1->3)-linked arabinoside decorations of polymeric wheat arabinoxylan. It exhibits very low activity against sugar beet arabinan. {ECO:0000269|PubMed:16336192}.

Catalytic activity: Reaction=Hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides.; EC=3.2.1.55; Evidence={ECO:0000269|PubMed:16336192};

Biophysicochemical properties: Kinetic parameters: KM=5.5 uM for wheat arabinoxylan (at 37 degrees Celsius and at pH 7) {ECO:0000269|PubMed:16336192}; KM=0.25 mM for p-nitrophenyl alpha-L-arabinofuranoside (pNP-Araf)(at 37 degrees Celsius and at pH 7) {ECO:0000269|PubMed:16336192}; KM=0.55 mM for alpha-(1->5)-linked arabinotriose (at 37 degrees Celsius and at pH 7) {ECO:0000269|PubMed:16336192}; KM=0.95 mM for alpha-(1->3)-linked arabinoside of xylobiose (at 37 degrees Celsius and at pH 7) {ECO:0000269|PubMed:16336192}; pH dependence: Optimum pH is 6.0. {ECO:0000269|PubMed:16336192}; Temperature dependence: Optimum temperature is 60 degrees Celsius. {ECO:0000269|PubMed:16336192};

Pathway: Glycan metabolism; L-arabinan degradation.

Subunit: Homohexamer; trimer of dimers. {ECO:0000269|PubMed:16336192}.

Subcellular location: Cytoplasm {ECO:0000305|PubMed:16336192}.

Similarity: Belongs to the glycosyl hydrolase 51 family. {ECO:0000305}.

Annotations taken from UniProtKB at the EBI.


Organism:		Hungateiclostridium thermocellum (strain ATCC 27405 / DSM 1237 / JCM 9322 / NBRC 103400 / NCIMB 10682 / NRRL B-4536 / VPI 7372) (Clostridium thermocellum).
Taxonomy:		Bacteria; Firmicutes; Clostridia; Eubacteriales; Oscillospiraceae; Acetivibrio.



Function:		Involved in the degradation of arabinan and is a key enzyme in the complete degradation of the plant cell wall. Catalyzes the cleavage of terminal alpha-(1->5)-arabinofuranosyl bonds in small oligosaccharides as alpha-(1->5)-linked arabinobiose/arabinotriose, but does not display significant activity against linear non-substituted arabinan. It is also highly efficient in the cleavage of alpha-(1->3)- linked arabinoside of xylobiose and of the alpha-(1->3)-linked arabinoside decorations of polymeric wheat arabinoxylan. It exhibits very low activity against sugar beet arabinan. {ECO:0000269\|PubMed:16336192}.


Catalytic activity:		Reaction=Hydrolysis of terminal non-reducing alpha-L-arabinofuranoside residues in alpha-L-arabinosides.; EC=3.2.1.55; Evidence={ECO:0000269\|PubMed:16336192};
Biophysicochemical properties:		Kinetic parameters: KM=5.5 uM for wheat arabinoxylan (at 37 degrees Celsius and at pH 7) {ECO:0000269\|PubMed:16336192}; KM=0.25 mM for p-nitrophenyl alpha-L-arabinofuranoside (pNP-Araf)(at 37 degrees Celsius and at pH 7) {ECO:0000269\|PubMed:16336192}; KM=0.55 mM for alpha-(1->5)-linked arabinotriose (at 37 degrees Celsius and at pH 7) {ECO:0000269\|PubMed:16336192}; KM=0.95 mM for alpha-(1->3)-linked arabinoside of xylobiose (at 37 degrees Celsius and at pH 7) {ECO:0000269\|PubMed:16336192}; pH dependence: Optimum pH is 6.0. {ECO:0000269\|PubMed:16336192}; Temperature dependence: Optimum temperature is 60 degrees Celsius. {ECO:0000269\|PubMed:16336192};
Pathway:		Glycan metabolism; L-arabinan degradation.
Subunit:		Homohexamer; trimer of dimers. {ECO:0000269\|PubMed:16336192}.
Subcellular location:		Cytoplasm {ECO:0000305\|PubMed:16336192}.
Similarity:		Belongs to the glycosyl hydrolase 51 family. {ECO:0000305}.