2his
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The catalytic mechanism of 'retaining' beta-glycosidases has been the | + | The catalytic mechanism of 'retaining' beta-glycosidases has been the subject of considerable interest and debate for many years. The visualization of a covalent glycosyl enzyme intermediate by X-ray crystallography was first accomplished with a saccharide substrate substituted with fluorine at its 2-position. The structure implicated major roles for residue His 205 and for the 2-hydroxyl position of the proximal saccharide in binding and catalysis. Here we have studied the kinetic behavior of various His 205 mutants. One of these mutants, a double mutant H205N/E127A, has been used to stabilize a covalent glycosyl-enzyme intermediate involving an unsubstituted sugar, permitting crystallographic analysis of the interactions between its 2-hydroxyl group and the enzyme. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Nitz, M.]] | [[Category: Nitz, M.]] | ||
[[Category: Notenboom, V.]] | [[Category: Notenboom, V.]] | ||
| - | [[Category: Rose, D | + | [[Category: Rose, D R.]] |
| - | [[Category: Warren, R | + | [[Category: Warren, R A.J.]] |
| - | [[Category: Wither, S | + | [[Category: Wither, S G.]] |
[[Category: a/b barrel]] | [[Category: a/b barrel]] | ||
[[Category: hydrolase]] | [[Category: hydrolase]] | ||
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[[Category: xylanase/cellulase]] | [[Category: xylanase/cellulase]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:42:20 2008'' |
Revision as of 15:42, 21 February 2008
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CELLULOMONAS FIMI XYLANASE/CELLULASE DOUBLE MUTANT E127A/H205N WITH COVALENT CELLOBIOSE
Overview
The catalytic mechanism of 'retaining' beta-glycosidases has been the subject of considerable interest and debate for many years. The visualization of a covalent glycosyl enzyme intermediate by X-ray crystallography was first accomplished with a saccharide substrate substituted with fluorine at its 2-position. The structure implicated major roles for residue His 205 and for the 2-hydroxyl position of the proximal saccharide in binding and catalysis. Here we have studied the kinetic behavior of various His 205 mutants. One of these mutants, a double mutant H205N/E127A, has been used to stabilize a covalent glycosyl-enzyme intermediate involving an unsubstituted sugar, permitting crystallographic analysis of the interactions between its 2-hydroxyl group and the enzyme.
About this Structure
2HIS is a Single protein structure of sequence from Cellulomonas fimi. Active as Cellulose 1,4-beta-cellobiosidase, with EC number 3.2.1.91 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Insights into transition state stabilization of the beta-1,4-glycosidase Cex by covalent intermediate accumulation in active site mutants., Notenboom V, Birsan C, Nitz M, Rose DR, Warren RA, Withers SG, Nat Struct Biol. 1998 Sep;5(9):812-8. PMID:9731776
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