1h4h
From Proteopedia
| Line 4: | Line 4: | ||
==Overview== | ==Overview== | ||
| - | The glycoside hydrolase sequence-based classification reveals two families | + | The glycoside hydrolase sequence-based classification reveals two families of enzymes which hydrolyse the beta-1,4-linked backbone of xylan, xylanases, termed families GH-10 and GH-11. Family GH-11 xylanases are intriguing in that catalysis is performed via a covalent intermediate adopting an unusual (2,5)B (boat) conformation, a conformation which also fulfils the stereochemical constraints of the oxocarbenium ion-like transition state. Here, the 1.9 A structure of a nucleophile, E94A, mutant of the Xyn11 from Bacillus agaradhaerens in complex with xylotriose is presented. Intriguingly, this complex also adopts the (2,5)B conformation in the -1 subsite, with the vacant space provided by the Glu-->Ala mutation allowing the sugar to adopt the alpha-configuration at C1. The structure of the covalent 2-deoxy-2-fluoroxylobiosyl-enzyme intermediate has been extended to atomic (1.1 A) resolution. |
==About this Structure== | ==About this Structure== | ||
| Line 15: | Line 15: | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Danielsen, S.]] | [[Category: Danielsen, S.]] | ||
| - | [[Category: Davies, G | + | [[Category: Davies, G J.]] |
[[Category: Sabini, E.]] | [[Category: Sabini, E.]] | ||
[[Category: Schulein, M.]] | [[Category: Schulein, M.]] | ||
| - | [[Category: Wilson, K | + | [[Category: Wilson, K S.]] |
[[Category: boat conformation]] | [[Category: boat conformation]] | ||
[[Category: intermediate]] | [[Category: intermediate]] | ||
| Line 26: | Line 26: | ||
[[Category: xylanase]] | [[Category: xylanase]] | ||
| - | ''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 12:57:16 2008'' |
Revision as of 10:57, 21 February 2008
|
OLIGOSACCHARIDE-BINDING TO FAMILY 11 XYLANASES: BOTH COVALENT INTERMEDIATE AND MUTANT-PRODUCT COMPLEXES DISPLAY 2,5B CONFORMATIONS AT THE ACTIVE-CENTRE
Overview
The glycoside hydrolase sequence-based classification reveals two families of enzymes which hydrolyse the beta-1,4-linked backbone of xylan, xylanases, termed families GH-10 and GH-11. Family GH-11 xylanases are intriguing in that catalysis is performed via a covalent intermediate adopting an unusual (2,5)B (boat) conformation, a conformation which also fulfils the stereochemical constraints of the oxocarbenium ion-like transition state. Here, the 1.9 A structure of a nucleophile, E94A, mutant of the Xyn11 from Bacillus agaradhaerens in complex with xylotriose is presented. Intriguingly, this complex also adopts the (2,5)B conformation in the -1 subsite, with the vacant space provided by the Glu-->Ala mutation allowing the sugar to adopt the alpha-configuration at C1. The structure of the covalent 2-deoxy-2-fluoroxylobiosyl-enzyme intermediate has been extended to atomic (1.1 A) resolution.
About this Structure
1H4H is a Single protein structure of sequence from Bacillus agaradhaerens. Active as Endo-1,4-beta-xylanase, with EC number 3.2.1.8 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Oligosaccharide binding to family 11 xylanases: both covalent intermediate and mutant product complexes display (2,5)B conformations at the active centre., Sabini E, Wilson KS, Danielsen S, Schulein M, Davies GJ, Acta Crystallogr D Biol Crystallogr. 2001 Sep;57(Pt 9):1344-7. Epub 2001, Aug 23. PMID:11526340
Page seeded by OCA on Thu Feb 21 12:57:16 2008
