Structural basis of S-adenosylmethionine-dependent allosteric transition from active to inactive states in methylenetetrahydrofolate reductase.
Nat Commun
; 15(1): 5167, 2024 Jun 17.
Article
in En
| MEDLINE
| ID: mdl-38886362
ABSTRACT
Methylenetetrahydrofolate reductase (MTHFR) is a pivotal flavoprotein connecting the folate and methionine methyl cycles, catalyzing the conversion of methylenetetrahydrofolate to methyltetrahydrofolate. Human MTHFR (hMTHFR) undergoes elaborate allosteric regulation involving protein phosphorylation and S-adenosylmethionine (AdoMet)-dependent inhibition, though other factors such as subunit orientation and FAD status remain understudied due to the lack of a functional structural model. Here, we report crystal structures of Chaetomium thermophilum MTHFR (cMTHFR) in both active (R) and inhibited (T) states. We reveal FAD occlusion by Tyr361 in the T-state, which prevents substrate interaction. Remarkably, the inhibited form of cMTHFR accommodates two AdoMet molecules per subunit. In addition, we conducted a detailed investigation of the phosphorylation sites in hMTHFR, three of which were previously unidentified. Based on the structural framework provided by our cMTHFR model, we propose a possible mechanism to explain the allosteric structural transition of MTHFR, including the impact of phosphorylation on AdoMet-dependent inhibition.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
S-Adenosylmethionine
/
Chaetomium
/
Methylenetetrahydrofolate Reductase (NADPH2)
Limits:
Humans
Language:
En
Journal:
Nat Commun
Journal subject:
BIOLOGIA
/
CIENCIA
Year:
2024
Document type:
Article
Affiliation country: