2. Academic Validation
  3. Polyketide Synthase-Mediated O-Methyloxime Formation in the Biosynthesis of the Oximidine Anticancer Agents

Polyketide Synthase-Mediated O-Methyloxime Formation in the Biosynthesis of the Oximidine Anticancer Agents

  • Angew Chem Int Ed Engl. 2023 Aug 21;62(34):e202304476. doi: 10.1002/anie.202304476.
Eveline Vriens 1 2,  Dries De Ruysscher 1 2,  Angus N M Weir 1 2,  Sofie Dekimpe 1 2,  Gert Steurs 3,  Ahmed Shemy 4,  Leentje Persoons 5,  Ana Rita Santos 6,  Christopher Williams 7,  Dirk Daelemans 5,  Matthew P Crump 7,  Arnout Voet 4,  Wim De Borggraeve 8,  Eveline Lescrinier 9,  Joleen Masschelein 1 2
Affiliations

Affiliations

  • 1 Laboratory for Biomolecular Discovery and Engineering, Department of Biology, KU Leuven, 3001, Heverlee, Belgium.
  • 2 VIB-KU Leuven Center for Microbiology, 3001, Heverlee, Belgium.
  • 3 Department of Chemistry, KU Leuven, 3001, Heverlee, Belgium.
  • 4 Laboratory for Biomolecular Modelling and Design, Department of Chemistry, KU Leuven, 3001, Heverlee, Belgium.
  • 5 Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven, 3000, Leuven, Belgium.
  • 6 VIB Discovery Sciences, 3001, Heverlee, Belgium.
  • 7 School of Chemistry, University of Bristol, Bristol, BS8 1TS, UK.
  • 8 Sustainable Chemistry for Metals and Molecules, Department of Chemistry, KU Leuven, 3001, Heverlee, Belgium.
  • 9 Laboratory for Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, 3000, Leuven, Belgium.
PMID: 37218580 DOI: 10.1002/anie.202304476
Abstract

Bacterial trans-acyltransferase polyketide synthases (trans-AT PKSs) are modular megaenzymes that employ unusual catalytic domains to assemble diverse bioactive natural products. One such PKS is responsible for the biosynthesis of the oximidine Anticancer agents, oxime-substituted benzolactone enamides that inhibit vacuolar H+ -ATPases. Here, we describe the identification of the oximidine gene cluster in Pseudomonas baetica and the characterization of four novel oximidine variants, including a structurally simpler intermediate that retains potent Anticancer activity. Using a combination of in vivo, in vitro and computational approaches, we experimentally elucidate the oximidine biosynthetic pathway and reveal an unprecedented mechanism for O-methyloxime formation. We show that this process involves a specialized monooxygenase and methyltransferase domain and provide insight into their activity, mechanism and specificity. Our findings expand the catalytic capabilities of trans-AT PKSs and identify potential strategies for the production of novel oximidine analogues.

Keywords

Bacterial Natural Products; Biosynthesis; Enzymology; Genome Mining; Polyketides.

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