title: Structural and functional studies of the glycoside hydrolase family 3 β-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. β-Glucosidases are involved in the last step of the degradation of cellulosic biomass and hydrolyse the β-glycosidic linkage between two adjacent molecules in dimers and oligomers of glucose. In this study, it is shown that substituting the β-glucosidase from H. jecorina (HjCel3A) with the β-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 β-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.
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Gudmundsson
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Hansson
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden.
authors.forename: Saeid
authors.initials: S
authors.lastname: Karkehabadi
authors.affiliation: Department of Cell and Molecular Biology, Uppsala University, Box 596, 751 24 Uppsala, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Larsson
authors.affiliation: Laboratory for Protein Biochemistry and Biomolecular Engineering, Ghent University, Ledeganckstraat 35, B-9000 Ghent, Belgium.
authors.forename: Ingeborg
authors.initials: I
authors.lastname: Stals
authors.affiliation: DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA.
authors.forename: Steve
authors.initials: S
authors.lastname: Kim
authors.affiliation: DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA.
authors.forename: Sergio
authors.initials: S
authors.lastname: Sunux
authors.affiliation: DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA.
authors.forename: Meredith
authors.initials: M
authors.lastname: Fujdala
authors.affiliation: DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA.
authors.forename: Edmund
authors.initials: E
authors.lastname: Larenas
authors.affiliation: DuPont Industrial Biosciences, 925 Page Mill Road, Palo Alto, CA 94304, USA.
authors.forename: Thijs
authors.initials: T
authors.lastname: Kaper
authors.affiliation: Department of Chemistry and Biotechnology, Swedish University of Agricultural Sciences, Box 7015, 750 07 Uppsala, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Sandgren
mesh_terms: D018360:Crystallography, X-Ray; D032641:Eurotiales / Q000737:chemistry / Q000201:enzymology* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D006868:Hydrolysis; D035901:Hypocrea / Q000737:chemistry / Q000201:enzymology / Q000378:metabolism; D008031:Lignin / Q000378:metabolism; D008958:Models, Molecular; D011487:Protein Conformation; D055503:Protein Multimerization; D001617:beta-Glucosidase / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; C036909:lignocellulose; D008031:Lignin; D001617:beta-Glucosidase
keywords: Cel3A; Rasamsonia emersonii; biodegradation; crystal structure; glycoproteins; glycoside hydrolase; thermophilic fungus; β-glucosidase