1N8F

Crystal structure of E24Q mutant of phenylalanine-regulated 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHP synthase) from Escherichia Coli in complex with Mn2+ and PEP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.209 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The High-Resolution Structure of 3-Deoxy-D-arabino-heptulosonate-7-phosphate Synthase Reveals a Twist in the Plane of Bound Phosphoenolpyruvate

Shumilin, I.A.Bauerle, R.Kretsinger, R.H.

(2003) Biochemistry 42: 3766-3776

  • DOI: 10.1021/bi027257p

  • PubMed Abstract: 
  • 3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS), the first enzyme of the aromatic biosynthetic pathway in microorganisms and plants, catalyzes the aldol-like condensation of phosphoenolpyruvate (PEP) and D-erythrose 4-phosphate (E4P) wit ...

    3-Deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHPS), the first enzyme of the aromatic biosynthetic pathway in microorganisms and plants, catalyzes the aldol-like condensation of phosphoenolpyruvate (PEP) and D-erythrose 4-phosphate (E4P) with the formation of DAHP. The native and the selenomethionine-substituted forms of the phenylalanine-regulated isozyme [DAHPS(Phe)] from Escherichia coli were crystallized in complex with PEP and a metal cofactor, Mn(2+), but the crystals displayed disorder in their unit cells, preventing satisfactory refinement. However, the crystal structure of the E24Q mutant form of DAHPS(Phe) in complex with PEP and Mn(2+) has been determined at 1.75 A resolution. Unlike the tetrameric wild-type enzyme, the E24Q enzyme is dimeric in solution, as a result of the mutational perturbation of four intersubunit salt bridges that are critical for tetramer formation. The protein chain conformation and subunit arrangement in the crystals of E24Q and wild-type DAHPS are very similar. However, the interaction of Mn(2+) and PEP in the enzymatically active E24Q mutant complex differs from the Pb(2+)-PEP and Mn(2+)-phosphoglycolate interactions in two enzymatically inactive wild-type complexes whose structures have been determined previously. The geometry of PEP bound in the active site of the E24Q enzyme deviates from planarity due to a 30 degrees twist of the carboxylate plane relative to the enol plane. In addition, seven water molecules are within contact distance of PEP, two of which are close enough to its C2 atom to serve as the nucleophile required in the reaction.


    Organizational Affiliation

    Department of Biology, University of Virginia, Charlottesville, Virginia 22903-2477, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
DAHP Synthetase
A, B, C, D
350Escherichia coli (strain K12)Gene Names: aroG
EC: 2.5.1.54
Find proteins for P0AB91 (Escherichia coli (strain K12))
Go to UniProtKB:  P0AB91
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MN
Query on MN

Download SDF File 
Download CCD File 
A, B, C, D
MANGANESE (II) ION
Mn
WAEMQWOKJMHJLA-UHFFFAOYSA-N
 Ligand Interaction
SO4
Query on SO4

Download SDF File 
Download CCD File 
A, B, C, D
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
PEP
Query on PEP

Download SDF File 
Download CCD File 
A, B, C, D
PHOSPHOENOLPYRUVATE
C3 H5 O6 P
DTBNBXWJWCWCIK-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.75 Å
  • R-Value Free: 0.237 
  • R-Value Work: 0.209 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 213.224α = 90.00
b = 53.277β = 116.90
c = 150.245γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
CNSphasing
HKL-2000data collection
ARPmodel building
CCP4data scaling
TRUNCATEdata reduction
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2003-04-22
    Type: Initial release
  • Version 1.1: 2008-04-28
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance