Structural and functional studies of the glycoside hydrolase family 3 beta-glucosidase Cel3A from the moderately thermophilic fungus Rasamsonia emersonii

Abstract

The filamentous fungus Hypocrea jecorina produces a number of cellulases and hemicellulases that act in a concerted fashion on biomass and degrade it into monomeric or oligomeric sugars. beta-Glucosidases are involved in the last step of the degradation of cellulosic biomass and hydrolyse the beta-glycosidic linkage between two adjacent molecules in dimers and oligomers of glucose. In this study, it is shown that substituting the beta-glucosidase from H. jecorina (HjCel3A) with the beta-glucosidase Cel3A from the thermophilic fungus Rasamsonia emersonii (ReCel3A) in enzyme mixtures results in increased efficiency in the saccharification of lignocellulosic materials. Biochemical characterization of ReCel3A, heterologously produced in H. jecorina, reveals a preference for disaccharide substrates over longer gluco-oligosaccharides. Crystallographic studies of ReCel3A revealed a highly N-glycosylated three-domain dimeric protein, as has been observed previously for glycoside hydrolase family 3 beta-glucosidases. The increased thermal stability and saccharification yield and the superior biochemical characteristics of ReCel3A compared with HjCel3A and mixtures containing HjCel3A make ReCel3A an excellent candidate for addition to enzyme mixtures designed to operate at higher temperatures.

Keywords

glycoside hydrolase; beta-glucosidase; biodegradation; crystal structure; Rasamsonia emersonii; Cel3A; glycoproteins; thermophilic fungus

Published in

Acta Crystallographica. Section d, Structural Biology
2016, volume: 72, pages: 860-870
Publisher: INT UNION CRYSTALLOGRAPHY

SLU Authors

• Gudmundsson, Mikael

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

• Hansson, Henrik

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

• Karkehabadi, Saeid

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

• Sandgren, Mats

  • The Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Biochemistry and Molecular Biology
Structural Biology
Biophysics

Publication identifier

• DOI: https://doi.org/10.1107/S2059798316008482

Permanent link to this page (URI)

https://res.slu.se/id/publ/79376