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Witzgall F, Depke T, Hoffmann M, Empting M, Brönstrup M, Müller R, Blankenfeldt W. The Alkylquinolone Repertoire of Pseudomonas aeruginosa is Linked to Structural Flexibility of the FabH-like 2-Heptyl-3-hydroxy-4(1H)-quinolone (PQS) Biosynthesis Enzyme PqsBC. Chembiochem 2018; 19:1531-1544. [PMID: 29722462 DOI: 10.1002/cbic.201800153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Indexed: 12/22/2022]
Abstract
Pseudomonas aeruginosa is a bacterial pathogen that causes life-threatening infections in immunocompromised patients. It produces a large armory of saturated and mono-unsaturated 2-alkyl-4(1H)-quinolones (AQs) and AQ N-oxides (AQNOs) that serve as signaling molecules to control the production of virulence factors and that are involved in membrane vesicle formation and iron chelation; furthermore, they also have, for example, antibiotic properties. It has been shown that the β-ketoacyl-acyl-carrier protein synthase III (FabH)-like heterodimeric enzyme PqsBC catalyzes the last step in the biosynthesis of the most abundant AQ congener, 2-heptyl-4(1H)-quinolone (HHQ), by condensing octanoyl-coenzyme A (CoA) with 2-aminobenzoylacetate (2-ABA), but the basis for the large number of other AQs/AQNOs produced by P. aeruginosa is not known. Here, we demonstrate that PqsBC uses different medium-chain acyl-CoAs to produce various saturated AQs/AQNOs and that it also biosynthesizes mono-unsaturated congeners. Further, we determined the structures of PqsBC in four different crystal forms at 1.5 to 2.7 Å resolution. Together with a previous report, the data reveal that PqsBC adopts open, intermediate, and closed conformations that alter the shape of the acyl-binding cavity and explain the promiscuity of PqsBC. The different conformations also allow us to propose a model for structural transitions that accompany the catalytic cycle of PqsBC that might have broader implications for other FabH-enzymes, for which such structural transitions have been postulated but have never been observed.
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Affiliation(s)
- Florian Witzgall
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Tobias Depke
- Department Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Michael Hoffmann
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Martin Empting
- Department Drug Design and Optimization, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Mark Brönstrup
- Department Chemical Biology, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany
| | - Rolf Müller
- Department Microbial Natural Products, Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz Centre for Infection Research, Campus E8.1, 66123, Saarbrücken, Germany.,Department of Pharmacy, Saarland University, Campus E8.1, 66123, Saarbrücken, Germany
| | - Wulf Blankenfeldt
- Department Structure and Function of Proteins, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, 38124, Braunschweig, Germany.,Institute for Biochemistry, Biotechnology and Bioinformatics, Technische Universität Braunschweig, Spielmannstrasse 7, 38106, Braunschweig, Germany
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Lee PJ, Bhonsle JB, Gaona HW, Huddler DP, Heady TN, Kreishman-Deitrick M, Bhattacharjee A, McCalmont WF, Gerena L, Lopez-Sanchez M, Roncal NE, Hudson TH, Johnson JD, Prigge ST, Waters NC. Targeting the fatty acid biosynthesis enzyme, beta-ketoacyl-acyl carrier protein synthase III (PfKASIII), in the identification of novel antimalarial agents. J Med Chem 2009; 52:952-63. [PMID: 19191586 DOI: 10.1021/jm8008103] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The importance of fatty acids to the human malaria parasite, Plasmodium falciparum, and differences due to a type I fatty acid synthesis (FAS) pathway in the parasite, make it an attractive drug target. In the present study, we developed and a utilized a pharmacophore to select compounds for testing against PfKASIII, the initiating enzyme of FAS. This effort identified several PfKASIII inhibitors that grouped into various chemical classes of sulfides, sulfonamides, and sulfonyls. Approximately 60% of the submicromolar inhibitors of PfKASIII inhibited in vitro growth of the malaria parasite. These compounds inhibited both drug sensitive and resistant parasites and testing against a mammalian cell line revealed an encouraging in vitro therapeutic index for the most active compounds. Docking studies into the active site of PfKASIII suggest a potential binding mode that exploits amino acid residues at the mouth of the substrate tunnel.
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Affiliation(s)
- Patricia J Lee
- Division of Experimental Therapeutics, Walter Reed Army Institute of Research, Silver Spring, Maryland 20910, USA
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