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Blomgren LKM, Huber M, Mackinnon SR, Bürer C, Baslé A, Yue WW, Froese DS, McCorvie TJ. Dynamic inter-domain transformations mediate the allosteric regulation of human 5, 10-methylenetetrahydrofolate reductase. Nat Commun 2024; 15:3248. [PMID: 38622112 PMCID: PMC11018872 DOI: 10.1038/s41467-024-47174-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 03/22/2024] [Indexed: 04/17/2024] Open
Abstract
5,10-methylenetetrahydrofolate reductase (MTHFR) commits folate-derived one-carbon units to generate the methyl-donor S-adenosyl-L-methionine (SAM). Eukaryotic MTHFR appends to the well-conserved catalytic domain (CD) a unique regulatory domain (RD) that confers feedback inhibition by SAM. Here we determine the cryo-electron microscopy structures of human MTHFR bound to SAM and its demethylated product S-adenosyl-L-homocysteine (SAH). In the active state, with the RD bound to a single SAH, the CD is flexible and exposes its active site for catalysis. However, in the inhibited state the RD pocket is remodelled, exposing a second SAM-binding site that was previously occluded. Dual-SAM bound MTHFR demonstrates a substantially rearranged inter-domain linker that reorients the CD, inserts a loop into the active site, positions Tyr404 to bind the cofactor FAD, and blocks substrate access. Our data therefore explain the long-distance regulatory mechanism of MTHFR inhibition, underpinned by the transition between dual-SAM and single-SAH binding in response to cellular methylation status.
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Affiliation(s)
- Linnea K M Blomgren
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, CH-8032, Switzerland
| | - Melanie Huber
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, CH-8032, Switzerland
| | - Sabrina R Mackinnon
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Céline Bürer
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, CH-8032, Switzerland
| | - Arnaud Baslé
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Wyatt W Yue
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, OX3 7DQ, UK.
| | - D Sean Froese
- Division of Metabolism and Children's Research Center, University Children's Hospital Zürich, University of Zürich, Zürich, CH-8032, Switzerland.
| | - Thomas J McCorvie
- Biosciences Institute, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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Mackinnon SR, Bezerra GA, Krojer T, Szommer T, von Delft F, Brennan PE, Yue WW. Novel Starting Points for Human Glycolate Oxidase Inhibitors, Revealed by Crystallography-Based Fragment Screening. Front Chem 2022; 10:844598. [PMID: 35601556 PMCID: PMC9114433 DOI: 10.3389/fchem.2022.844598] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/18/2022] [Indexed: 11/13/2022] Open
Abstract
Primary hyperoxaluria type I (PH1) is caused by AGXT gene mutations that decrease the functional activity of alanine:glyoxylate aminotransferase. A build-up of the enzyme’s substrate, glyoxylate, results in excessive deposition of calcium oxalate crystals in the renal tract, leading to debilitating renal failure. Oxidation of glycolate by glycolate oxidase (or hydroxy acid oxidase 1, HAO1) is a major cellular source of glyoxylate, and siRNA studies have shown phenotypic rescue of PH1 by the knockdown of HAO1, representing a promising inhibitor target. Here, we report the discovery and optimization of six low-molecular-weight fragments, identified by crystallography-based fragment screening, that bind to two different sites on the HAO1 structure: at the active site and an allosteric pocket above the active site. The active site fragments expand known scaffolds for substrate-mimetic inhibitors to include more chemically attractive molecules. The allosteric fragments represent the first report of non-orthosteric inhibition of any hydroxy acid oxidase and hold significant promise for improving inhibitor selectivity. The fragment hits were verified to bind and inhibit HAO1 in solution by fluorescence-based activity assay and surface plasmon resonance. Further optimization cycle by crystallography and biophysical assays have generated two hit compounds of micromolar (44 and 158 µM) potency that do not compete with the substrate and provide attractive starting points for the development of potent and selective HAO1 inhibitors.
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Affiliation(s)
- Sabrina R. Mackinnon
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Gustavo A. Bezerra
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Tobias Krojer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Tamas Szommer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Frank von Delft
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, United Kingdom
| | - Paul E. Brennan
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Target Discovery Institute, University of Oxford, Oxford, United Kingdom
- *Correspondence: Paul E. Brennan, ; Wyatt W. Yue,
| | - Wyatt W. Yue
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- *Correspondence: Paul E. Brennan, ; Wyatt W. Yue,
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