Fowler, Claire A, Hemsworth, Glyn R orcid.org/0000-0002-8226-1380, Cuskin, Fiona et al. (5 more authors) (2018) Structure and function of a glycoside hydrolase family 8 endoxylanase from Teredinibacter turnerae. Acta crystallographica. Section D, Structural biology. pp. 946-955. ISSN 2059-7983
Abstract
The biological conversion of lignocellulosic matter into high-value chemicals or biofuels is of increasing industrial importance as the sector slowly transitions away from nonrenewable sources. Many industrial processes involve the use of cellulolytic enzyme cocktails - a selection of glycoside hydrolases and, increasingly, polysaccharide oxygenases - to break down recalcitrant plant polysaccharides. ORFs from the genome of Teredinibacter turnerae, a symbiont hosted within the gills of marine shipworms, were identified in order to search for enzymes with desirable traits. Here, a putative T. turnerae glycoside hydrolase from family 8, hereafter referred to as TtGH8, is analysed. The enzyme is shown to be active against β-1,4-xylan and mixed-linkage (β-1,3,β-1,4) marine xylan. Kinetic parameters, obtained using high-performance anion-exchange chromatography with pulsed amperometric detection and 3,5-dinitrosalicyclic acid reducing-sugar assays, show that TtGH8 catalyses the hydrolysis of β-1,4-xylohexaose with a k cat/K m of 7.5 × 10 7 M -1 min -1 but displays maximal activity against mixed-linkage polymeric xylans, hinting at a primary role in the degradation of marine polysaccharides. The three-dimensional structure of TtGH8 was solved in uncomplexed and xylobiose-, xylotriose- and xylohexaose-bound forms at approximately 1.5 Å resolution; the latter was consistent with the greater k cat/K m for hexasaccharide substrates. A 2,5B boat conformation observed in the -1 position of bound xylotriose is consistent with the proposed conformational itinerary for this class of enzyme. This work shows TtGH8 to be effective at the degradation of xylan-based substrates, notably marine xylan, further exemplifying the potential of T. turnerae for effective and diverse biomass degradation.
Metadata
Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2018, The Author(s). | ||||
Keywords: | Biofuels, Biomass, Cellulolytic enzymes, Glycoside hydrolase, Marine polysaccharides, Shipworms, Teredinibacter turnerae, Xylans/metabolism, Plants/chemistry, Polysaccharides/metabolism, Gram-Negative Facultatively Anaerobic Rods/enzymology, Gammaproteobacteria/enzymology, Endo-1,4-beta Xylanases/chemistry, Protein Conformation, Bacterial Proteins/chemistry, Kinetics, Glycoside Hydrolases/chemistry, Plant Cells/metabolism | ||||
Dates: |
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Institution: | The University of York | ||||
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) | ||||
Funding Information: |
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Depositing User: | Pure (York) | ||||
Date Deposited: | 15 Oct 2018 11:10 | ||||
Last Modified: | 06 Dec 2023 12:34 | ||||
Published Version: | https://doi.org/10.1107/S2059798318009737 | ||||
Status: | Published | ||||
Refereed: | Yes | ||||
Identification Number: | https://doi.org/10.1107/S2059798318009737 | ||||
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