Abstract
The three-dimensional structures of endo-1,4-xylanase II (XYNII) from Trichoderma reesei complexed with 4,5-epoxypentyl beta-D-xyloside (X-O-C5),3,4-epoxybutyl beta-D-xyloside (X-O-C4), and 2,3-epoxypropyl beta-D-xyloside (X-O-C3) were determined by X-ray crystallography. High-resolution measurement revealed clear electron densities for each ligand. Both X-O-C5 and X-O-C3 were found to form a covalent bond with the putative nucleophile Glu86. Unexpectedly, X-O-C4 was found to bind to the putative acid/base catalyst Glu177. In all three complexes, clear conformational changes were found in XYNII compared to the native structure. These changes were largest in the X-O-C3 complex structure.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Benzoates / metabolism
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Benzoic Acid
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Binding Sites
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Carbohydrate Conformation
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Carbohydrate Sequence
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Crystallography, X-Ray
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Endo-1,4-beta Xylanases
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Enzyme Inhibitors / chemistry
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Enzyme Inhibitors / metabolism*
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Epoxy Compounds / metabolism*
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Glycosides / chemistry
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Glycosides / metabolism*
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Hydrogen Bonding
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Hydrogen-Ion Concentration
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Models, Molecular
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Molecular Sequence Data
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Molecular Structure
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Oligosaccharides / chemistry
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Oligosaccharides / metabolism
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Protein Conformation
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Trichoderma / enzymology*
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Xylosidases / antagonists & inhibitors
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Xylosidases / chemistry*
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Xylosidases / metabolism
Substances
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Benzoates
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Enzyme Inhibitors
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Epoxy Compounds
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Glycosides
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Oligosaccharides
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xylosides
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Benzoic Acid
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Xylosidases
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Endo-1,4-beta Xylanases