Structural elucidation of the specificity of the antibacterial agent triclosan for malarial enoyl ACP reductase | Academic Article individual record

The human malaria parasite Plasmodium falciparum synthesizes fatty acids using a type II pathway that is absent in humans. The final step in fatty acid elongation is catalyzed by enoyl acyl carrier protein reductase, a validated antimicrobial drug target. Here, we report the cloning and expression of the P. falciparum enoyl acyl carrier protein reductase gene, which encodes a 50-kDa protein (PfENR) predicted to target to the unique parasite apicoplast. Purified PfENR was crystallized, and its structure resolved as a binary complex with NADH, a ternary complex with triclosan and NAD(+), and as ternary complexes bound to the triclosan analogs 1 and 2 with NADH. Novel structural features were identified in the PfENR binding loop region that most closely resembled bacterial homologs; elsewhere the protein was similar to ENR from the plant Brassica napus (root mean square for Calphas, 0.30 A). Triclosan and its analogs 1 and 2 killed multidrug-resistant strains of intra-erythrocytic P. falciparum parasites at sub to low micromolar concentrations in vitro. These data define the structural basis of triclosan binding to PfENR and will facilitate structure-based optimization of PfENR inhibitors.

author list (cited authors)
Perozzo, R., Kuo, M., Sidhu, A., Valiyaveettil, J. T., Bittman, R., Jacobs, W. R., Fidock, D. A., & Sacchettini, J. C.
publication date
  • Anti-Infective Agents
  • DNA Primers
  • Triclosan
  • Base Sequence
  • Oxidoreductases
  • Amino Acid Sequence
  • Cloning, Molecular
  • Molecular Sequence Data
  • Enoyl-(acyl-carrier-protein) Reductase (nadh)
  • Protein Structure, Tertiary
  • Models, Molecular
  • Animals
  • Sequence Homology, Amino Acid
  • Plasmodium Falciparum
  • Substrate Specificity
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