Download MendeleyOligosaccharide binding to family 11 xylanases: both covalent intermediate and mutant product complexes display (2,5)B conformations at the active centre.
Sabini, E., Wilson, K.S., Danielsen, S., Schulein, M., Davies, G.J.(2001) Acta Crystallogr D Biol Crystallogr 57: 1344-1347
- PubMed: 11526340
- DOI: https://doi.org/10.1107/s0907444901010873
- Primary Citation of Related Structures:
1H4G, 1H4H - 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.
- Department of Chemistry, Structural Biology Laboratory, University of York, Heslington, York YO10 5DD, England.
Organizational Affiliation:
