2C07

Oxoacyl-ACP reductase of Plasmodium falciparum


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.202 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Kinetic, Inhibition and Structural Studies on 3-Oxoacyl-Acp Reductase from Plasmodium Falciparum, a Key Enzyme in Fatty Acid Biosynthesis.

Wickramasinghe, S.R.Inglis, K.A.Urch, J.E.Muller, S.Van Aalten, D.M.F.Fairlamb, A.H.

(2006) Biochem.J. 393: 447

  • DOI: 10.1042/BJ20050832

  • PubMed Abstract: 
  • Type II fatty acid biosynthesis represents an attractive target for the discovery of new antimalarial drugs. Previous studies have identified malarial ENR (enoyl acyl-carrier-protein reductase, or FabI) as the target for the antiseptic triclosan. In ...

    Type II fatty acid biosynthesis represents an attractive target for the discovery of new antimalarial drugs. Previous studies have identified malarial ENR (enoyl acyl-carrier-protein reductase, or FabI) as the target for the antiseptic triclosan. In the present paper, we report the biochemical properties and 1.5 A (1 A=0.1 nm) crystal structure of OAR (3-oxoacyl acyl-carrier-protein reductase, or FabG), the second reductive step in fatty acid biosynthesis and its inhibition by hexachlorophene. Under optimal conditions of pH and ionic strength, Plasmodium falciparum OAR displays kinetic properties similar to those of OAR from bacteria or plants. Activity with NADH is <3% of that with NADPH. Fluorescence enhancement studies indicate that NADPH can bind to the free enzyme, consistent with kinetic and product inhibition studies suggesting a steady-state ordered mechanism. The crystal structure reveals a tetramer with a sulphate ion bound in the cofactor-binding site such that the side chains of the catalytic triad of serine, tyrosine and lysine are aligned in an active conformation, as previously observed in the Escherichia coli OAR-NADP+ complex. A cluster of positively charged residues is positioned at the entrance to the active site, consistent with the proposed recognition site for the physiological substrate (3-oxoacyl-acyl-carrier protein) in E. coli OAR. The antibacterial and anthelminthic agent hexachlorophene is a potent inhibitor of OAR (IC50 2.05 microM) displaying non-linear competitive inhibition with respect to NADPH. Hexachlorophene (EC50 6.2 microM) and analogues such as bithionol also have antimalarial activity in vitro, suggesting they might be useful leads for further development.


    Organizational Affiliation

    Division of Biological Chemistry and Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
3-OXOACYL-(ACYL-CARRIER PROTEIN) REDUCTASE
A
285Plasmodium falciparumMutation(s): 0 
Find proteins for Q8I2S7 (Plasmodium falciparum)
Go to UniProtKB:  Q8I2S7
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.5 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.202 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 73.121α = 90.00
b = 73.121β = 90.00
c = 100.176γ = 90.00
Software Package:
Software NamePurpose
SCALEPACKdata scaling
AMoREphasing
CNSrefinement
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-20
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance