2D0K

Methionine-free mutant of Escherichia coli dihydrofolate reductase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.205 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Evolutional Design of a Hyperactive Cysteine- and Methionine-free Mutant of Escherichia coli Dihydrofolate Reductase

Iwakura, M.Maki, K.Takahashi, H.Takenawa, T.Yokota, A.Katayanagi, K.Kamiyama, T.Gekko, K.

(2006) J.Biol.Chem. 281: 13234-13246

  • DOI: 10.1074/jbc.M508823200

  • PubMed Abstract: 
  • We developed a strategy for finding out the adapted variants of enzymes, and we applied it to an enzyme, dihydrofolate reductase (DHFR), in terms of its catalytic activity so that we successfully obtained several hyperactive cysteine- and methionine- ...

    We developed a strategy for finding out the adapted variants of enzymes, and we applied it to an enzyme, dihydrofolate reductase (DHFR), in terms of its catalytic activity so that we successfully obtained several hyperactive cysteine- and methionine-free variants of DHFR in which all five methionyl and two cysteinyl residues were replaced by other amino acid residues. Among them, a variant (M1A/M16N/M20L/M42Y/C85A/M92F/C152S), named as ANLYF, has an approximately seven times higher k(cat) value than wild type DHFR. Enzyme kinetics and crystal structures of the variant were investigated for elucidating the mechanism of the hyperactivity. Steady-state and transient binding kinetics of the variant indicated that the kinetic scheme of the catalytic cycle of ANLYF was essentially the same as that of wild type, showing that the hyperactivity was brought about by an increase of the dissociation rate constants of tetrahydrofolate from the enzyme-NADPH-tetrahydrofolate ternary complex. The crystal structure of the variant, solved and refined to an R factor of 0.205 at 1.9-angstroms resolution, indicated that an increased structural flexibility of the variant and an increased size of the N-(p-aminobenzoyl)-L-glutamate binding cleft induced the increase of the dissociation constant. This was consistent with a large compressibility (volume fluctuation) of the variant. A comparison of folding kinetics between wild type and the variant showed that the folding of these two enzymes was similar to each other, suggesting that the activity enhancement of the enzyme can be attained without drastic changes of the folding mechanism.


    Organizational Affiliation

    National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan. masa-iwakura@aist.go.jp




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Dihydrofolate reductase
A, B
159Escherichia coli (strain K12)Mutation(s): 7 
Gene Names: folA (tmrA)
EC: 1.5.1.3
Find proteins for P0ABQ4 (Escherichia coli (strain K12))
Go to UniProtKB:  P0ABQ4
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CL
Query on CL

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

Download SDF File 
Download CCD File 
A, B
FOLIC ACID
C19 H19 N7 O6
OVBPIULPVIDEAO-LBPRGKRZSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
FOLKd: 9510 nM BINDINGMOAD
FOLKd: 9510 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.284 
  • R-Value Work: 0.205 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 79.580α = 90.00
b = 56.690β = 106.81
c = 85.140γ = 90.00
Software Package:
Software NamePurpose
AMoREphasing
DENZOdata reduction
X-PLORrefinement
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

  • Deposited Date: 2005-08-04 
  • Released Date: 2006-02-28 
  • Deposition Author(s): Katayanagi, K.

Revision History 

  • Version 1.0: 2006-02-28
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance