1DYJ

ISOMORPHOUS CRYSTAL STRUCTURES OF ESCHERICHIA COLI DIHYDROFOLATE REDUCTASE COMPLEXED WITH FOLATE, 5-DEAZAFOLATE AND 5,10-DIDEAZATETRAHYDROFOLATE: MECHANISTIC IMPLICATIONS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Isomorphous crystal structures of Escherichia coli dihydrofolate reductase complexed with folate, 5-deazafolate, and 5,10-dideazatetrahydrofolate: mechanistic implications.

Reyes, V.M.Sawaya, M.R.Brown, K.A.Kraut, J.

(1995) Biochemistry 34: 2710-2723

  • Primary Citation of Related Structures:  1DRH, 1DYH, 1DYI

  • PubMed Abstract: 
  • Crystal structures of Escherichia coli dihydrofolate reductase (ecDHFR, EC 1.5.1.3) in binary complexes with folate, 5-deazafolate (5dfol), and 5,10-dideazatetrahydrofolate (ddTHF) have been refined to R-factors of 13.7%, 14.9%, and 14.5%, respective ...

    Crystal structures of Escherichia coli dihydrofolate reductase (ecDHFR, EC 1.5.1.3) in binary complexes with folate, 5-deazafolate (5dfol), and 5,10-dideazatetrahydrofolate (ddTHF) have been refined to R-factors of 13.7%, 14.9%, and 14.5%, respectively, all at 1.9 A. All three are isomorphous with a previously reported binary complex of ecDHFR with methotrexate (MTX), in space group P6(1), two molecules per asymmetric unit [Bolin, J. T., Filman, D. J., Matthews, D. A., Hamlin, R. C., & Kraut, J. (1982) J. Biol. Chem. 257, 13650-13662]. A hitherto unobserved water molecule is hydrogen bonded to the pteridine N5 and O4 in both molecules of the asymmetric unit of the folate complex (but not the 5dfol or ddTHF complexes), supporting the hypothesis that N5 protonation of bound substrate, an important step of the DHFR reaction, occurs by way of such a water molecule. There is no indication of a hydrogen bond between N8 of 5dfol and the backbone carbonyl of Ile-5, suggesting that the bacterial enzyme, unlike the human enzyme [Davies, J. F., II, Delcamp, T. J., Prendergast, N. J., Ashford, V. A., Freisheim, J. H., & Kraut, J. (1990) Biochemistry 29, 9467-9479], does not favor protonation at N8. Perhaps this explains why bacterial DHFR is much less effective than vertebrate DHFR in folate reduction. When the ecDHFR.NADPH complex (space group P3221; M. R. Sawaya, in preparation) is superimposed on the folate and 5dfol complexes, the distances from pteridine C6 to nicotinamide C4 were found to be 2.9 and 2.8 A, respectively, in close agreement with the theoretically calculated optimal distance in the transition state for hydride transfer [Wu, Y. D., & Houk, K. N. (1987) J. Am. Chem. Soc. 109, 906-908, 2226-2227]. In contrast to the planar ring system of folate or 5dfol, the reduced pteridine ring of ddTHF is severely puckered and bent toward the nicotinamide pocket, with the reduced pyridine ring assuming a half-chair type of conformation. This change in shape causes the pteridine ring to bind with O4 closer to Trp-22(N epsilon 1) by over 0.5 A, so that an invariant water molecule now bridges these two atoms with ideal hydrogen bonds. Furthermore, while the pABA rings of folate and 5dfol are nearly coincident and closer to the alpha C helix than to the alpha B helix, those of MTX and ddTHF are displaced along the binding crevice by approximately 1.1 and 0.6 A, respectively, and are equidistant from alpha B and alpha C.(ABSTRACT TRUNCATED AT 400 WORDS)


    Related Citations: 
    • Crystal Structures of Escherichia Coli and Lactobacillus Casei Dihydrofolate Reductase at 1.7 Angstroms Resolution. II. Environment of Bound Nadph and Implications for Catalysis
      Filman, D.J.,Bolin, J.T.,Matthews, D.A.,Kraut, J.
      (1982) J.Biol.Chem. 257: 13663
    • Crystal Structure of Unliganded Escherichia Coli Dihydrofolate Reductase. Ligand Induced Conformational Changes and Cooperativity Binding
      Bystroff, C.,Kraut, J.
      (1991) Biochemistry 30: 2227
    • Crystal Structures of Escherichia Coli and Lactobacillus Casei Dihydrofolate Reductase Refined at 1.7 Angstroms Resolution I. General Features and Binding of Methotrexate
      Bolin, J.T.,Filman, D.J.,Matthews, D.A.,Hamlin, R.C.,Kraut, J.
      (1982) J.Biol.Chem. 257: 13650
    • Crystal Structures of Recombinant Human Dihydrofolate Reductase Complexed with Folate and 5-Deazafolate
      Davies II, J.F.,Delcamp, T.J.,Prendergast, N.J.,Freisheim, J.H.,Kraut, J.
      (1990) Biochemistry 29: 8467
    • Crystal Structures of Escherichia Coli Dihydrofolate Reductase and Folate.Nadp+ Ternary Complex. Substrate Binding and a Model for the Transition State
      Bystroff, C.,Oatley, S.J.,Kraut, J.
      (1990) Biochemistry 29: 3263


    Organizational Affiliation

    Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla 92093-0317.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DIHYDROFOLATE REDUCTASE
A, B
159Escherichia coli (strain K12)Gene Names: folA (tmrA)
EC: 1.5.1.3
Find proteins for P0ABQ4 (Escherichia coli (strain K12))
Go to UniProtKB:  P0ABQ4
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
DDF
Query on DDF

Download SDF File 
Download CCD File 
A, B
5,10-DIDEAZATETRAHYDROFOLIC ACID
C21 H25 N5 O6
ZUQBAQVRAURMCL-DOMZBBRYSA-N
 Ligand Interaction
CL
Query on CL

Download SDF File 
Download CCD File 
A, B
CHLORIDE ION
Cl
VEXZGXHMUGYJMC-UHFFFAOYSA-M
 Ligand Interaction
CA
Query on CA

Download SDF File 
Download CCD File 
B
CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.85 Å
  • Space Group: P 61
Unit Cell:
Length (Å)Angle (°)
a = 93.114α = 90.00
b = 93.114β = 90.00
c = 73.894γ = 120.00
Software Package:
Software NamePurpose
TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 1994-10-26 
  • Released Date: 1995-06-03 
  • Deposition Author(s): Reyes, V.M., Kraut, J.

Revision History 

  • Version 1.0: 1995-06-03
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance