Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.212 

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This is version 1.3 of the entry. See complete history


The structure and properties of methylenetetrahydrofolate reductase from Escherichia coli suggest how folate ameliorates human hyperhomocysteinemia.

Guenther, B.D.Sheppard, C.A.Tran, P.Rozen, R.Matthews, R.G.Ludwig, M.L.

(1999) Nat Struct Biol 6: 359-365

  • DOI: https://doi.org/10.1038/7594
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Elevated plasma homocysteine levels are associated with increased risk for cardiovascular disease and neural tube defects in humans. Folate treatment decreases homocysteine levels and dramatically reduces the incidence of neural tube defects. The flavoprotein methylenetetrahydrofolate reductase (MTHFR) is a likely target for these actions of folate. The most common genetic cause of mildly elevated plasma homocysteine in humans is the MTHFR polymorphism A222V (base change C677-->T). The X-ray analysis of E. coli MTHFR, reported here, provides a model for the catalytic domain that is shared by all MTHFRs. This domain is a beta8alpha8 barrel that binds FAD in a novel fashion. Ala 177, corresponding to Ala 222 in human MTHFR, is near the bottom of the barrel and distant from the FAD. The mutation A177V does not affect Km or k(cat) but instead increases the propensity for bacterial MTHFR to lose its essential flavin cofactor. Folate derivatives protect wild-type and mutant E. coli enzymes against flavin loss, and protect human MTHFR and the A222V mutant against thermal inactivation, suggesting a mechanism by which folate treatment reduces homocysteine levels.

  • Organizational Affiliation

    Biophysics Research Division, University of Michigan, Ann Arbor 48109-1055, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B, C
275Escherichia coliMutation(s): 0 
Gene Names: METF
Find proteins for P0AEZ1 (Escherichia coli (strain K12))
Explore P0AEZ1 
Go to UniProtKB:  P0AEZ1
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP0AEZ1
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.263 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.212 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 103α = 90
b = 128.2β = 121.6
c = 98.2γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1999-01-20
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2024-02-07
    Changes: Data collection, Database references, Derived calculations