ジャーナル: Nat Commun / 年: 2024 タイトル: Dynamic inter-domain transformations mediate the allosteric regulation of human 5, 10-methylenetetrahydrofolate reductase. 著者: Linnea K M Blomgren / Melanie Huber / Sabrina R Mackinnon / Céline Bürer / Arnaud Baslé / Wyatt W Yue / D Sean Froese / Thomas J McCorvie / 要旨: 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.
超分子 #1: Human 5,10-methylenetetrahydrofolate reductase in complex with S-...
超分子
名称: Human 5,10-methylenetetrahydrofolate reductase in complex with S-Adenosyl-L-homocysteine, regulatory domains with one catalytic domain タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: #1