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Title | Dynamic inter-domain transformations mediate the allosteric regulation of human 5, 10-methylenetetrahydrofolate reductase. |
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Journal, issue, pages | Nat Commun, Vol. 15, Issue 1, Page 3248, Year 2024 |
Publish date | Apr 15, 2024 |
Authors | Linnea K M Blomgren / Melanie Huber / Sabrina R Mackinnon / Céline Bürer / Arnaud Baslé / Wyatt W Yue / D Sean Froese / Thomas J McCorvie / |
PubMed 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 ...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. |
External links | Nat Commun / PubMed:38622112 / PubMed Central |
Methods | EM (single particle) |
Resolution | 2.8 - 3.14 Å |
Structure data | EMDB-18298, PDB-8qa4: EMDB-18299, PDB-8qa5: EMDB-18300, PDB-8qa6: |
Chemicals | ChemComp-SAH: ChemComp-HOH: ChemComp-FAD: ChemComp-SAM: |
Source |
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Keywords | FLAVOPROTEIN / Dis-inhibited / allosteric / folate / S-adenosylhomocysteine / Inhibited / S-Adenosylmethionin |