Hemsworth, GR orcid.org/0000-0002-8226-1380, Thompson, AJ, Stepper, J et al. (8 more authors) (2016) Structural dissection of a complex Bacteroides ovatus gene locus conferring xyloglucan metabolism in the human gut. Open Biology, 6 (7). ISSN 2046-2441
Abstract
The human gastrointestinal tract harbours myriad bacterial species, collectively termed the microbiota, that strongly influence human health. Symbiotic members of our microbiota play a pivotal role in the digestion of complex carbohydrates that are otherwise recalcitrant to assimilation. Indeed, the intrinsic human polysaccharide-degrading enzyme repertoire is limited to various starch based substrates; more complex polysaccharides demand microbial degradation. Select Bacteroidetes are responsible for the degradation of the ubiquitous vegetable xyloglucans (XyGs), through the concerted action of cohorts of enzymes and glycan-binding proteins encoded by specific xyloglucan utilization loci (XyGULs). Extending recent (meta)genomic, transcriptomic, and biochemical analyses, significant questions remain regarding the structural biology of the molecular machinery required for XyG saccharification. Here, we reveal the three-dimensional structures of an α−xylosidase, a β−glucosidase, and two α−L arabinofuranosidases from the Bacteroides ovatus XyGUL. Aided by bespoke ligand synthesis, our analyses highlight key adaptations in these enzymes that confer individual specificity for xyloglucan sidechains and dictate concerted, stepwise disassembly of xyloglucan oligosaccharides. In harness with our recent structural characterization of the vanguard endo-xyloglucanse and cell-surface glycan-binding proteins, the present analysis provides a near-complete structural view of xyloglucan recognition and catalysis by XyGUL proteins.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2016 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited. |
Keywords: | Xyloglucan; Polysaccharide Utilisation Loci; Glycoside hydrolases |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) The University of Leeds > Faculty of Biological Sciences (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 28 Jul 2016 14:55 |
Last Modified: | 05 Oct 2017 16:19 |
Published Version: | http://dx.doi.org/10.1098/rsob.160142 |
Status: | Published |
Publisher: | Royal Society, The |
Identification Number: | 10.1098/rsob.160142 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:102986 |