title: Identifying the Minimal Enzymes Required for Biosynthesis of Epoxyketone Proteasome Inhibitors.
abstract: Epoxyketone proteasome inhibitors have attracted much interest due to their potential as anticancer drugs. Although the biosynthetic gene clusters for several peptidyl epoxyketone natural products have recently been identified, the enzymatic logic involved in the formation of the terminal epoxyketone pharmacophore has been relatively unexplored. Here, we report the identification of the minimal set of enzymes from the eponemycin gene cluster necessary for the biosynthesis of novel metabolites containing a terminal epoxyketone pharmacophore in Escherichia coli, a versatile and fast-growing heterologous host. This set of enzymes includes a non-ribosomal peptide synthetase (NRPS), a polyketide synthase (PKS), and an acyl-CoA dehydrogenase (ACAD) homologue. In addition to the in vivo functional reconstitution of these enzymes in E. coli, in vitro studies of the eponemycin NRPS and (13) C-labeled precursor feeding experiments were performed to advance the mechanistic understanding of terminal epoxyketone formation.
authors.affiliation: Department of Bioengineering, University of California, Berkeley, 2151 Berkeley Way, Berkeley, CA, 94704, USA.
authors.forename: Joyce
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Berkeley, 2151 Berkeley Way, Berkeley, CA, 94704, USA.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of California, Berkeley, 2151 Berkeley Way, Berkeley, CA, 94704, USA. wjzhang@berkeley.edu.|Physical Biosciences Division, Lawrence Berkeley National Laboratory, 2151 Berkeley Way, Berkeley, CA, 94704, USA. wjzhang@berkeley.edu.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000577:Amides / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D007659:Ketones / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D005810:Multigene Family; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D048630:Polyketide Synthases / Q000235:genetics / Q000378:metabolism*; D061988:Proteasome Inhibitors / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D012694:Serine / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000737:chemistry
chemical_list: D000577:Amides; D007659:Ketones; D061988:Proteasome Inhibitors; C063282:eponemycin; D012694:Serine; D048630:Polyketide Synthases; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase
keywords: acyl-CoA dehydrogenase; biosynthesis; epoxyketones; peptide/polyketide hybrid; proteasome inhibitor