title: Production of New Cladosporin Analogues by Reconstitution of the Polyketide Synthases Responsible for the Biosynthesis of this Antimalarial Agent.
abstract: The antimalarial agent cladosporin is a nanomolar inhibitor of the Plasmodium falciparum lysyl-tRNA synthetase, and exhibits activity against both blood- and liver-stage infection. Cladosporin can be isolated from the fungus Cladosporium cladosporioides, where it is biosynthesized by a highly reducing (HR) and a non-reducing (NR) iterative type I polyketide synthase (PKS) pair. Genome sequencing of the host organism and subsequent heterologous expression of these enzymes in Saccharomyces cerevisiae produced cladosporin, confirming the identity of the putative gene cluster. Incorporation of a pentaketide intermediate analogue indicated a 5+3 assembly by the HR PKS Cla2 and the NR PKS Cla3 during cladosporin biosynthesis. Advanced-intermediate analogues were synthesized and incorporated by Cla3 to furnish new cladosporin analogues. A putative lysyl-tRNA synthetase resistance gene was identified in the cladosporin gene cluster. Analysis of the active site emphasizes key structural features thought to be important in resistance to cladosporin.
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
authors.forename: Rachel V K
authors.initials: RV
authors.lastname: Cochrane
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
authors.forename: Randy
authors.initials: R
authors.lastname: Sanichar
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
authors.forename: Gareth R
authors.initials: GR
authors.lastname: Lambkin
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada).
authors.forename: Béla
authors.initials: B
authors.lastname: Reiz
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA).
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: Department of Chemical and Biomolecular Engineering and Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095 (USA).
authors.forename: Yi
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Department of Chemistry, University of Alberta, Edmonton, Alberta, T6G 2G2 (Canada). john.vederas@ualberta.ca.
authors.forename: John C
authors.initials: JC
authors.lastname: Vederas
mesh_terms: D000962:Antimalarials / Q000378:metabolism*; D049934:Isocoumarins / Q000737:chemistry* / Q000378:metabolism; D048630:Polyketide Synthases / Q000378:metabolism*
chemical_list: D000962:Antimalarials; D049934:Isocoumarins; D048630:Polyketide Synthases; C000488:cladosporin
keywords: antimalarial agents; biosynthesis; cladosporin; heterologous expression; polyketides