Applied Biochemistry and Biotechnology

, Volume 63, Issue 1, pp 315–325

Polysaccharide hydrolase folds diversity of structure and convergence of function

  • Michael E. Himmel
  • P. Andrew Karplus
  • Joshua Sakon
  • Willam S. Adney
  • John O. Baker
  • Steven R. Thomas
Session 2 Biological Research

DOI: 10.1007/BF02920433

Cite this article as:
Himmel, M.E., Karplus, P.A., Sakon, J. et al. Appl Biochem Biotechnol (1997) 63: 315. doi:10.1007/BF02920433

Abstract

Polysaccharide glycosyl hydrolases are a group of enzymes that hydrolyze the glycosidic bond between carbohydrates or between a carbohydrate and a noncarbohydrate moiety. Here we illustrate that traditional schemes for grouping enzymes, such as by substrate specificity or by organism of origin, are not appropriate when thinking of structure-function relationships and protein engineering. Instead, sequence comparisons and structural studies reveal that enzymes with diverse specificities and from diverse organisms can be placed into groups among which mechanisms are largely conserved and insights are likely to be transferrable. In particular, we illustrate how enzymes have been grouped using protein sequence alignment algorithms and hydrophobic cluster analysis. Unfortunately for those who seek to improve cellulase function by design, cellulases are distributed throughout glycosyl hydrolase Families 1,5,6,7,9, and 45. These cellulase families include members from widely different fold types, i.e., the TIM-barrel, βαβ-barrel variant (a TIM-barrel-like structure that is imperfectly superimposable on the TIM-barrel template), β-sandwich, and α-helix circular array. This diversity in cellulase fold structure must be taken into account when considering the transfer and application of design strategies between various cellulases.

Index Entries

Cellulasesxylanasesamylasesglycosyl hydrolasesstructural foldsX-ray structureshydrophobic cluster families

Copyright information

© Humana Press Inc. 1997

Authors and Affiliations

  • Michael E. Himmel
    • 1
  • P. Andrew Karplus
    • 2
  • Joshua Sakon
    • 2
  • Willam S. Adney
    • 1
  • John O. Baker
    • 1
  • Steven R. Thomas
    • 1
  1. 1.Biotechnology Center for Renewable Fuels and ChemicalsNational Renewable Energy LaboratoryGolden
  2. 2.Section of BiochemistryMolecular and Cell Biology Cornell UniversityIthaca