Literature summary for 3.2.1.8 extracted from

Mamo, G.; Thunnissen, M.; Hatti-Kaul, R.; Mattiasson, B.
An alkaline active xylanase: insights into mechanisms of high pH catalytic adaptation (2009), Biochimie, 91, 1187-1196.

Crystallization (Commentary)

Crystallization (Comment)	Organism
purified recombinant enzyme, by hanging drop vapour diffusion method, room temperature, 0.001 ml of protein solution containing 5 mg/ml protein is mixed with 0.001 ml of reservoir solution containing 30% v/v 2-methyl-2,4-pentanediol, 20 mM CaCl2, and 100 mM sodium acetate, pH 4.6, and equilibrated against 1 ml of reservoir solution, X-ray diffraction structure determination and analysis at 2.1 A resolution, molecular replacement method	Halalkalibacterium halodurans

Crystallization (Comment)

Organism

purified recombinant enzyme, by hanging drop vapour diffusion method, room temperature, 0.001 ml of protein solution containing 5 mg/ml protein is mixed with 0.001 ml of reservoir solution containing 30% v/v 2-methyl-2,4-pentanediol, 20 mM CaCl2, and 100 mM sodium acetate, pH 4.6, and equilibrated against 1 ml of reservoir solution, X-ray diffraction structure determination and analysis at 2.1 A resolution, molecular replacement method

Halalkalibacterium halodurans

Protein Variants

Protein Variants	Comment	Organism
V169A/I170F/D171N	site-directed mutagenesis, the mutant shows a pH optimum of pH 7.0, incontrast to the wild-type enzyme which has an optimum at pH 9.0-9.5	Halalkalibacterium halodurans

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
additional information	Halalkalibacterium halodurans	the alkaliphilic bacterium produces an alkaline active xylanase, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues, mechanisms of high pH stability and catalysis, overview	?	-	?
additional information	Halalkalibacterium halodurans S7	the alkaliphilic bacterium produces an alkaline active xylanase, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues, mechanisms of high pH stability and catalysis, overview	?	-	?

Organism

Organism	UniProt	Comment	Textmining
Halalkalibacterium halodurans	Q17TM8	-	-
Halalkalibacterium halodurans S7	Q17TM8	-	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
additional information	the alkaliphilic bacterium produces an alkaline active xylanase, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues, mechanisms of high pH stability and catalysis, overview	Halalkalibacterium halodurans	?	-	?
additional information	residues Val169, Ile170 and Asp171 are important to hydrolyze xylan at high pH	Halalkalibacterium halodurans	?	-	?
additional information	the alkaliphilic bacterium produces an alkaline active xylanase, the alkaline active xylanases have highly acidic surfaces and fewer solvent exposed alkali labile residues, mechanisms of high pH stability and catalysis, overview	Halalkalibacterium halodurans S7	?	-	?
additional information	residues Val169, Ile170 and Asp171 are important to hydrolyze xylan at high pH	Halalkalibacterium halodurans S7	?	-	?

Subunits

Subunits	Comment	Organism
More	the enzyme has the common eightfold TIM-barrel structure of family 10 xylanases, however, unlike non-alkaline active xylanases, it has a highly negatively charged surface and a deeper active site cleft, structure comparisons, overview	Halalkalibacterium halodurans

Synonyms

Synonyms	Comment	Organism
alkaline active xylanase	-	Halalkalibacterium halodurans
xylanase	-	Halalkalibacterium halodurans

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
9	9.5	residues Val169, Ile170 and Asp171 are important to hydrolyze xylan at high pH, mechanisms of high pH stability and catalysis, overview	Halalkalibacterium halodurans