Structural insight into industrially relevant glucoamylases: flexible positions of starch-binding domains

Christian Roth, Olga V. Moroz, Antonio Ariza, Lars K. Skov, Keiichi Ayabe, Gideon J. Davies, Keith S. Wilson*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Glucoamylases are one of the most important classes of enzymes in the industrial degradation of starch biomass. They consist of a catalytic domain and a carbohydrate-binding domain (CBM), with the latter being important for the interaction with the polymeric substrate. Whereas the catalytic mechanisms and structures of the individual domains are well known, the spatial arrangement of the domains with respect to each other and its influence on activity are not fully understood. Here, the structures of three industrially used fungal glucoamylases, two of which are full length, have been crystallized and determined. It is shown for the first time that the relative orientation between the CBM and the catalytic domain is flexible, as they can adopt different orientations independently of ligand binding, suggesting a role as an anchor to increase the contact time and the relative concentration of substrate near the active site. The flexibility in the orientations of the two domains presented a considerable challenge for the crystallization of the enzymes.

Original languageEnglish
Pages (from-to)463-470
Number of pages8
JournalActa crystallographica. Section D, Structural biology
Issue number5
Publication statusPublished - 1 May 2018

Bibliographical note

© International Union of Crystallography, 2018. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.


  • Aspergillus niger
  • carbohydrate-binding module
  • glucoamylases
  • Hormoconis resinae
  • Penicillium oxalicum
  • starch biomass degradation

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