Robertson, A., Cruz-Navarrete, F.A., Wood, H. et al. (6 more authors) (2022) An enzyme with high catalytic proficiency utilizes distal site substrate binding energy to stabilize the closed state but at the expense of substrate inhibition. ACS Catalysis, 12 (5). pp. 3149-3164. ISSN 2155-5435
Abstract
Understanding the factors that underpin the enormous catalytic proficiencies of enzymes is fundamental to catalysis and enzyme design. Enzymes are, in part, able to achieve high catalytic proficiencies by utilizing the binding energy derived from nonreacting portions of the substrate. In particular, enzymes with substrates containing a nonreacting phosphodianion group coordinated in a distal site have been suggested to exploit this binding energy primarily to facilitate a conformational change from an open inactive form to a closed active form, rather than to either induce ground state destabilization or stabilize the transition state. However, detailed structural evidence for the model is limited. Here, we use β-phosphoglucomutase (βPGM) to investigate the relationship between binding a phosphodianion group in a distal site, the adoption of a closed enzyme form, and catalytic proficiency. βPGM catalyzes the isomerization of β-glucose 1-phosphate to glucose 6-phosphate via phosphoryl transfer reactions in the proximal site, while coordinating a phosphodianion group of the substrate(s) in a distal site. βPGM has one of the largest catalytic proficiencies measured and undergoes significant domain closure during its catalytic cycle. We find that side chain substitution at the distal site results in decreased substrate binding that destabilizes the closed active form but is not sufficient to preclude the adoption of a fully closed, near-transition state conformation. Furthermore, we reveal that binding of a phosphodianion group in the distal site stimulates domain closure even in the absence of a transferring phosphoryl group in the proximal site, explaining the previously reported β-glucose 1-phosphate inhibition. Finally, our results support a trend whereby enzymes with high catalytic proficiencies involving phosphorylated substrates exhibit a greater requirement to stabilize the closed active form.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2022 American Chemical Society. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (http://creativecommons.org/licenses/by/4.0) |
Keywords: | Enzyme catalytic proficiency; Phosphoryl transfer mechanism; Transition state analogue; X-ray crystallography; NMR spectroscopy |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Biosciences (Sheffield) |
Funding Information: | Funder Grant number HIGHER EDUCATION FUNDING COUNCIL FOR ENGLAND UNSPECIFIED WELLCOME TRUST (THE) 087850/Z/08/Z BIOTECHNOLOGY AND BIOLOGICAL SCIENCES RESEARCH COUNCIL BB/E017541/1 BIOTECHNOLOGY AND BIOLOGICAL SCIENCES RESEARCH COUNCIL BB/I002146/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S01358X/1 BIOTECHNOLOGY AND BIOLOGICAL SCIENCES RESEARCH COUNCIL BB/R000727/1 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 23 Feb 2022 12:49 |
Last Modified: | 10 Feb 2023 14:12 |
Status: | Published |
Publisher: | American Chemical Society |
Refereed: | Yes |
Identification Number: | 10.1021/acscatal.1c05524 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:183780 |