Biological Assembly 1  

 3D View: Structure | 1D-3D View | Validation Report

Global Symmetry: Dihedral - D2  (3D View)
Global Stoichiometry: Homo 4-mer - A4 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 6.73 kDa 
• Atom Count: 515 
• Modelled Residue Count: 60 
• Deposited Residue Count: 62 
• Unique protein chains: 1

1VIE

STRUCTURE OF DIHYDROFOLATE REDUCTASE

• PDB DOI: 10.2210/pdb1VIE/pdb

• Classification: OXIDOREDUCTASE
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1996-10-03 Released: 1997-10-22 
• Deposition Author(s): Narayana, N., Matthews, D.A., Howell, E.E., Xuong, N.-H.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Work: 0.192 
• R-Value Observed: 0.192 

Literature

A plasmid-encoded dihydrofolate reductase from trimethoprim-resistant bacteria has a novel D2-symmetric active site.

Narayana, N., Matthews, D.A., Howell, E.E., Nguyen-huu, X.

(1995) Nat Struct Biol 2: 1018-1025

• PubMed: 7583655 
• DOI: 10.1038/nsb1195-1018
• Primary Citation of Related Structures:  
  1VIE, 1VIF


• PubMed Abstract: 
  

Bacteria expressing R67-plasmid encoded dihydrofolate reductase (R67 DHFR) exhibit high-level resistance to the antibiotic trimethoprim. Native R67 DHFR is a 34,000 M(r) homotetramer which exists in equilibrium with an inactive dimeric form. The structure of native R67 DHFR has now been solved at 1.7 A resolution and is unrelated to that of chromosomal DHFR. Homotetrameric R67 DHFR has an unusual pore, 25 A in length, passing through the middle of the molecule. Two folate molecules bind asymmetrically within the pore indicating that the enzyme's active site consists of symmetry related binding surfaces from all four identical units.

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Related Citations: 

• Does R67 Dihydrofolate Reductase Possess a Proton Donor?
  Holland, J.C., Linn, C.E., Digiammarino, E., Nichols, R., Howell, E.E.
  (1993) Adv Exp Med Biol 338: 493

• Construction of a Synthetic Gene for an R-Plasmid-Encoded Dihydrofolate Reductase and Studies on the Role of the N-Terminus in the Protein
  Reece, L.J., Nichols, R., Ogden, R.C., Howell, E.E.
  (1991) Biochemistry 30: 10895

• Crystal Structure of a Novel Trimethoprim-Resistant Dihydrofolate Reductase Specified in Escherichia Coli by R-Plasmid R67
  Matthews, D.A., Smith, S.L., Baccanari, D.P., Burchall, J.J., Oatley, S.J., Kraut, J.
  (1986) Biochemistry 25: 4194

• The Amino Acid Sequence of the Trimethoprim-Resistant Dihydrofolate Reductase Specified in Escherichia Coli by R-Plasmid R67
  Stone, D., Smith, S.L.
  (1979) J Biol Chem 254: 10857

• Trimethoprim Resistance Determined by R Factors
  Fleming, M.P., Datta, N., Gruneberg, R.N.
  (1972) Br Med J 1: 726

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Organizational Affiliation: 

Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla 92093, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
DIHYDROFOLATE REDUCTASE	A	62	Escherichia coli	Mutation(s): 0  Gene Names: SYNTHETIC GENE EC: 1.5.1.3
UniProt
Find proteins for P00383 (Escherichia coli) Explore P00383  Go to UniProtKB:  P00383

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Work: 0.192 
• R-Value Observed: 0.192 
• Space Group: I 4₁ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 68.74	α = 90
b = 68.74	β = 90
c = 52.45	γ = 90

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
UCSD	data reduction
UCSD	data scaling
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1996-10-03 
• Released Date: 1997-10-22 
Deposition Author(s): Narayana, N., Matthews, D.A., Howell, E.E., Xuong, N.-H.

Revision History  

• Version 1.0: 1997-10-22
  Type: Initial release
  
• Version 1.1: 2008-03-24
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance