Bisintercalator depsipeptides are a groupof natural non-ribosomal peptides (NRPs) with a C2-symmetric macrocyclicscaffold. Due to the intricate architectural complexity and antitumor potencyof these molecules, there has been of great interest in their total chemicalsynthesis, modes of action and biosynthesis. As a prototype of thedecadepsipeptide class, luzopeptins displays very strong antitumor andantiviral activities. The rare acylsubstituted tetrahydropyridazine-3-carboxylicacid (Thp) subunits in their structures are critical to the biologicalactivities. However, the biosynthetic mechanism of luzopeptins in nature hasnot been elucidated, therefore preventing the application of modern syntheticbiology approaches to its structural innovation and structure-functionrelationship studies.

Recently, Prof. Yi-Ling Du and colleagues,from the Zhejiang University School of Medcine, revealed the biosyntheticmachinery of luzopeptins in the soil actinomycetes Actinomadura luzonensis (Angew.Chem. Int. Ed. 2021, 60, 19821–19828). In this work, they reconstitute thecomplete enzymatic tailoring pathway in luzopeptin A biosynthesis through invivo genetic and in vitro biochemical approaches. Significantly, we found amultitasking cytochrome P450 enzyme that catalyzes four consecutive oxidations includingthe highly unusual carbon–nitrogen bond desaturation. Moreover, they identifieda membrane-bound acyltransferase that likely mediates the subsequentO-acetylation extracellularly, as a potential self-protective strategy for the producerstrain. Further genome mining of novel decadepsipeptides and an associated P450enzyme have provided mechanistic insights into the P450-mediatedcarbon–nitrogen bond desaturation. These results not only reveal the molecular basisof pharmacophore formation in bisintercalator decadepsipeptides, but also expandthe catalytic versatility of P450 family enzymes.