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Title: Structures of Pseudomonas aeruginosa β-ketoacyl-(acyl-carrier-protein) synthase II (FabF) and a C164Q mutant provide templates for antibacterial drug discovery and identify a buried potassium ion and a ligand-binding site that is an artefact of the crystal form

Journal Article · · Acta crystallographica. Section F, Structural biology communications
 [1]; ;  [2];  [3];  [4];  [1]
  1. Johannes Gutenberg-Universität, Staudinger Weg 5, 55128 Mainz (Germany)
  2. University of Dundee, Dundee DD1 4EH, Scotland (United Kingdom)
  3. Johannes Gutenberg-Universität, Jakob Welder Weg 26, 55128 Mainz (Germany)
  4. Karolinska Institutet, 17 177 Stockholm (Sweden)

Three crystal structures of recombinant P. aeruginosa FabF are reported: the apoenzyme, an active-site mutant and a complex with a fragment of a natural product inhibitor. The characterization provides reagents and new information to support antibacterial drug discovery. Bacterial infections remain a serious health concern, in particular causing life-threatening infections of hospitalized and immunocompromised patients. The situation is exacerbated by the rise in antibacterial drug resistance, and new treatments are urgently sought. In this endeavour, accurate structures of molecular targets can support early-stage drug discovery. Here, crystal structures, in three distinct forms, of recombinant Pseudomonas aeruginosa β-ketoacyl-(acyl-carrier-protein) synthase II (FabF) are presented. This enzyme, which is involved in fatty-acid biosynthesis, has been validated by genetic and chemical means as an antibiotic target in Gram-positive bacteria and represents a potential target in Gram-negative bacteria. The structures of apo FabF, of a C164Q mutant in which the binding site is altered to resemble the substrate-bound state and of a complex with 3-(benzoylamino)-2-hydroxybenzoic acid are reported. This compound mimics aspects of a known natural product inhibitor, platensimycin, and surprisingly was observed binding outside the active site, interacting with a symmetry-related molecule. An unusual feature is a completely buried potassium-binding site that was identified in all three structures. Comparisons suggest that this may represent a conserved structural feature of FabF relevant to fold stability. The new structures provide templates for structure-based ligand design and, together with the protocols and reagents, may underpin a target-based drug-discovery project for urgently needed antibacterials.

OSTI ID:
22389088
Journal Information:
Acta crystallographica. Section F, Structural biology communications, Vol. 71, Issue Pt 8; Other Information: PMCID: PMC4528935; PMID: 26249693; PUBLISHER-ID: pq5015; PUBLISHER-ID: S2053230X15010614; OAI: oai:pubmedcentral.nih.gov:4528935; Copyright (c) Baum et al. 2015; This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.; Country of input: International Atomic Energy Agency (IAEA); ISSN 2053-230X
Country of Publication:
United States
Language:
English