Armstrong, Zachary and Davies, Gideon J orcid.org/0000-0002-7343-776X (2020) Structure and function of Bs164 β-mannosidase from Bacteroides salyersiae the founding member of glycoside hydrolase family GH164. The Journal of biological chemistry. pp. 4316-4326. ISSN 1083-351X
Abstract
Recent work exploring protein sequence space has revealed a new glycoside hydrolase (GH) family (GH164) of putative mannosidases. GH164 genes are present in several commensal bacteria, implicating these genes in the degradation of dietary glycans. However, little is known about the structure, mechanism of action and substrate specificity of these enzymes. Herein we report the biochemical characterization and crystal structures of the founding member of this family (Bs164) from the human gut symbiont Bacteroides salyersiae. Previous reports of this enzyme indicated that it has α-mannosidase activity, however we conclusively show that it cleaves only β-mannose linkages. Using NMR spectroscopy, detailed enzyme kinetics of wild-type and mutant Bs164, and multi-angle light scattering we found that it is a trimeric retaining β-mannosidase, that is susceptible to several known mannosidase inhibitors. X-ray crystallography revealed the structure of Bs164 - the first known structure of a GH164 - at 1.91 Å resolution. Bs164 is composed of three domains: a (β/α)8 barrel, a trimerization domain and a β-sandwich domain, representing a previously unobserved structural fold for β-mannosidases. Structures of Bs164 at 1.80-2.55 Å resolution in complex with the inhibitors noeuromycin, mannoimidazole or DNP 2-deoxy-2-fluoro-mannose reveal the residues essential for specificity and catalysis including the catalytic nucleophile (Glu297) and acid/base residue (Glu160). These findings further our knowledge of the mechanisms commensal microbes use for nutrient acquisition.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Armstrong and Davies. |
Dates: |
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Institution: | The University of York |
Academic Units: | The University of York > Faculty of Sciences (York) > Chemistry (York) |
Funding Information: | Funder Grant number BBSRC (BIOTECHNOLOGY AND BIOLOGICAL SCIENCES RESEARCH COUNCIL) BB/R001162/1 THE ROYAL SOCIETY RSRP\R\210004 |
Depositing User: | Pure (York) |
Date Deposited: | 22 Jan 2020 17:00 |
Last Modified: | 28 Dec 2024 00:10 |
Published Version: | https://doi.org/10.1074/jbc.RA119.011591 |
Status: | Published |
Refereed: | Yes |
Identification Number: | 10.1074/jbc.RA119.011591 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:155946 |
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