1H4H

Oligosaccharide-binding to family 11 xylanases: both covalent intermediate and mutant-product complexes display 2,5B conformations at the active-centre

Summary for 1H4H

• Entry DOI: 10.2210/pdb1h4h/pdb
• Related: 1H4G
• Descriptor: XYLANASE, beta-D-xylopyranose-(1-4)-beta-D-xylopyranose-(1-4)-alpha-D-xylopyranose (3 entities in total)
• Functional Keywords: glycoside hydrolase, xylanase, oligosaccharide, transition-state, intermediate, mutant, boat conformation
• Biological source: BACILLUS AGARADHAERENS
• Total number of polymer chains: 4
• Total formula weight: 94904.53

Authors

Sabini, E.,Wilson, K.S.,Danielsen, S.,Schulein, M.,Davies, G.J. (deposition date: 2001-05-11, release date: 2002-05-09, Last modification date: 2025-08-13)

Primary citation

Sabini, E.,Wilson, K.S.,Danielsen, S.,Schulein, M.,Davies, G.J.
Oligosaccharide binding to family 11 xylanases: both covalent intermediate and mutant product complexes display (2,5)B conformations at the active centre.
Acta Crystallogr.,Sect.D, 57:1344-1347, 2001

PubMed Abstract: 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.

PubMed: 11526340
DOI: 10.1107/s0907444901010873

Experimental method

X-RAY DIFFRACTION (1.9 Å)