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Glycosidases: Functions, Families and Folds

  1. Miriam P Kötzler,
  2. Susan M Hancock,
  3. Stephen G Withers

Published Online: 15 JUL 2014

DOI: 10.1002/9780470015902.a0020548.pub2

eLS

eLS

How to Cite

Kötzler, M. P., Hancock, S. M. and Withers, S. G. 2014. Glycosidases: Functions, Families and Folds. eLS. .

Author Information

  1. University of British Columbia, Vancouver, Canada

  1. Based in part on the previous version of this eLS article ‘Glycosidases: Functions, Families and Folds’ (2007) by Susan M Hancock and Stephen G Withers.

Publication History

  1. Published Online: 15 JUL 2014

Abstract

Glycosidases catalyse the hydrolysis of glycosidic linkages, thereby degrading oligosaccharides and glycoconjugates, the structurally most diverse class of biopolymers. These efficient and highly specific catalysts play important roles in biological processes thus a detailed knowledge of glycosidase function is invaluable for understanding and controlling diseases and for industrial applications. The classification of this huge class of enzymes into families on the basis of amino acid sequence has provided a highly valuable tool for the analysis of structure–function relationships. Furthermore, the steady increase in three-dimensional structural information is revealing further evolutionary relationships between glycosidase families. In addition to the majority of glycosidases that act via the classical Koshland mechanisms, a growing number of such enzymes that use unusual mechanisms are being uncovered. This confluence of bioinformatics, structural and mechanistic studies has greatly advanced glycosidase engineering and the development of specific glycosidase inhibitors.

Key Concepts:

  • Classification of glycosidases by sequence similarity in a comprehensive database CAZy has proven to be an invaluable tool to analyse their structures and functions.

  • Glycosidases adopt a variety of folds.

  • The vast majority of glycosidases act via Koshland mechanisms with either retention or inversion of the anomeric configuration.

  • Some glycosidases use unusual mechanisms employing hydration, elimination and/or redox steps.

  • Detailed mechanistic understanding of glycosidase mechanism has allowed the engineering of glycosynthases and the development of specific inhibitors.

Keywords:

  • glycosidase;
  • carbohydrate;
  • glycoconjugate;
  • enzyme;
  • hydrolysis;
  • mechanism;
  • catalysis;
  • hydrolase