Literature summary for 3.2.1.37 extracted from

Bruex, C.; Ben-David, A.; Shallom-Shezifi, D.; Leon, M.; Niefind, K.; Shoham, G.; Shoham, Y.; Schomburg, D.
The structure of an inverting GH43 beta-xylosidase from Geobacillus stearothermophilus with its substrate reveals the role of the three catalytic residues (2006), J. Mol. Biol., 359, 97-109.

Crystallization (Commentary)

Crystallization (Comment)	Organism
in complex with substrate xylobiose. The xylose moiety at the K1 subsite is held by a large number of hydrogen bonds, whereas only one hydroxyl of the xylose unit at the C1 subsite can create hydrogen bonds with the enzyme. The general base, Asp15, is located on the alpha-side of the K1 xylose sugar ring, 5.2 A from the anomeric carbon. This location enables it to activate a water molecule for a single displacement attack on the anomeric carbon, resulting in inversion of the anomeric configuration. Glu187, the general acid, is 2.4 A from the glycosidic oxygen atom and can protonate the leaving aglycon. The third catalytic carboxylic acid, Asp128, is 4 A from the general acid, modulating its pKa and keeping it in the correct orientation relative to the substrate	Geobacillus stearothermophilus

Crystallization (Comment)

Organism

in complex with substrate xylobiose. The xylose moiety at the K1 subsite is held by a large number of hydrogen bonds, whereas only one hydroxyl of the xylose unit at the C1 subsite can create hydrogen bonds with the enzyme. The general base, Asp15, is located on the alpha-side of the K1 xylose sugar ring, 5.2 A from the anomeric carbon. This location enables it to activate a water molecule for a single displacement attack on the anomeric carbon, resulting in inversion of the anomeric configuration. Glu187, the general acid, is 2.4 A from the glycosidic oxygen atom and can protonate the leaving aglycon. The third catalytic carboxylic acid, Asp128, is 4 A from the general acid, modulating its pKa and keeping it in the correct orientation relative to the substrate

Geobacillus stearothermophilus

Organism

Organism	UniProt	Comment	Textmining
Geobacillus stearothermophilus	-	isoform XynB3	-

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
xylobiose + H2O	-	Geobacillus stearothermophilus	2 beta-D-xylose	-	?

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Release 2023.1 (January 2023)