A PLP-dependent polyketide chain releasing mechanism in the biosynthesis of mycotoxin fumonisins in Fusarium verticillioides.

摘要: Fumonisins are polyketide-derived mycotoxins produced by several plant pathogenic fungi. The toxins cause fatal diseases in domestic animals and associated with esophageal cancer neural tube defects humans. contain a highly reduced, acyclic 18-carbon chain, which is synthesized an iterative polyketide synthase (PKS). This PKS does not thioesterase or cyclase domain that found other PKSs for the release of covalently linked chain. In this study, we expressed acyl carrier protein (ACP) FUM1 vitro loaded chains to ACP from acyl-CoA using promiscuous 4′-phosphopantetheinyl transferase. We then FUM8, homologous 2-oxoamine genes, yeast showed enzyme able offload ACP. Products resulted decarboxylative condensation between l-alanine acyl-S-ACP were detected GC−MS. activity was dependent on pyridoxal 5′-phosphate (PLP), C18...