RRC ID 78028
著者 Mendoza J, Purchal M, Yamada K, Koutmos M.
タイトル Structure of full-length cobalamin-dependent methionine synthase and cofactor loading captured in crystallo.
ジャーナル Nat Commun
Abstract Cobalamin-dependent methionine synthase (MS) is a key enzyme in methionine and folate one-carbon metabolism. MS is a large multi-domain protein capable of binding and activating three substrates: homocysteine, folate, and S-adenosylmethionine for methylation. Achieving three chemically distinct methylations necessitates significant domain rearrangements to facilitate substrate access to the cobalamin cofactor at the right time. The distinct conformations required for each reaction have eluded structural characterization as its inherently dynamic nature renders structural studies difficult. Here, we use a thermophilic MS homolog (tMS) as a functional MS model. Its exceptional stability enabled characterization of MS in the absence of cobalamin, marking the only studies of a cobalamin-binding protein in its apoenzyme state. More importantly, we report the high-resolution full-length MS structure, ending a multi-decade quest. We also capture cobalamin loading in crystallo, providing structural insights into holoenzyme formation. Our work paves the way for unraveling how MS orchestrates large-scale domain rearrangements crucial for achieving challenging chemistries.
巻・号 14(1)
ページ 6365
公開日 2023-10-11
DOI 10.1038/s41467-023-42037-4
PII 10.1038/s41467-023-42037-4
PMID 37821448
PMC PMC10567725
MeSH 5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase* / metabolism Folic Acid Methionine* / metabolism S-Adenosylmethionine / metabolism Vitamin B 12 / metabolism
IF 12.121
リソース情報
遺伝子材料 Thermus thermophilus expression plasmid TEx15A10 (THR006010)