3AM5

K316A mutant of Enoyl-ACP Reductase from Plasmodium falciparum (PfENR) in complex with triclosan


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.164 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Effect of substrate binding loop mutations on the structure, kinetics, and inhibition of enoyl acyl carrier protein reductase from plasmodium falciparum

Maity, K.Banerjee, T.Prabakaran, N.Surolia, N.Surolia, A.Suguna, K.

(2011) Iubmb Life 63: 30-41

  • DOI: 10.1002/iub.412
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Enoyl acyl carrier protein reductase (ENR), which catalyzes the final and rate limiting step of fatty acid elongation, has been validated as a potential drug target. Triclosan is known to be an effective inhibitor for this enzyme. We mutated the subs ...

    Enoyl acyl carrier protein reductase (ENR), which catalyzes the final and rate limiting step of fatty acid elongation, has been validated as a potential drug target. Triclosan is known to be an effective inhibitor for this enzyme. We mutated the substrate binding site residue Ala372 of the ENR of Plasmodium falciparum (PfENR) to Methionine and Valine which increased the affinity of the enzyme towards triclosan to almost double, close to that of Escherichia coli ENR (EcENR) which has a Methionine at the structurally similar position of Ala372 of PfENR. Kinetic studies of the mutants of PfENR and the crystal structure analysis of the A372M mutant revealed that a more hydrophobic environment enhances the affinity of the enzyme for the inhibitor. A triclosan derivative showed a threefold increase in the affinity towards the mutants compared to the wild type, due to additional interactions with the A372M mutant as revealed by the crystal structure. The enzyme has a conserved salt bridge which stabilizes the substrate binding loop and appears to be important for the active conformation of the enzyme. We generated a second set of mutants to check this hypothesis. These mutants showed loss of function, except in one case, where the crystal structure showed that the substrate binding loop is stabilized by a water bridge network.


    Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Enoyl-ACP reductase
A, B
329Plasmodium falciparumMutation(s): 1 
Gene Names: FabI
Find proteins for Q9BJJ9 (Plasmodium falciparum)
Go to UniProtKB:  Q9BJJ9
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAD
Query on NAD

Download SDF File 
Download CCD File 
A, B
NICOTINAMIDE-ADENINE-DINUCLEOTIDE
C21 H27 N7 O14 P2
BAWFJGJZGIEFAR-NNYOXOHSSA-N
 Ligand Interaction
TCL
Query on TCL

Download SDF File 
Download CCD File 
A, B
TRICLOSAN
C12 H7 Cl3 O2
XEFQLINVKFYRCS-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
TCLKi: 0 - 13.7 nM (98) BINDINGDB
TCLIC50: 49 - 200 nM (99) BINDINGDB
TCLKi: 38 nM BINDINGMOAD
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.164 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 131.110α = 90.00
b = 131.110β = 90.00
c = 82.780γ = 90.00
Software Package:
Software NamePurpose
MAR345dtbdata collection
SCALAdata scaling
PHASERphasing
REFMACrefinement
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-03-16
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance