Identification of the First Diketomorpholine Biosynthetic Pathway Using FAC-MS Technology

Area of Science:

• Biochemistry
• Genomics
• Metabolomics

Background:

• Filamentous fungi are a rich source of secondary metabolites with therapeutic potential.
• Genome sequencing reveals numerous uncharacterized biosynthetic gene clusters.
• Accessing and characterizing these metabolites is crucial for drug discovery.

Discussion:

• A novel platform combining fungal artificial chromosomes and metabolomic scoring (FAC-MS) was developed for screening and heterologous expression of gene clusters.
• This platform enabled the identification of the biosynthetic machinery for acu-dioxomorpholine from Aspergillus aculeatus.
• The acu-dioxomorpholine nonribosomal peptide synthetase contains a unique condensation domain (C_R) potentially involved in ester bond formation.

Key Insights:

• Stable isotope labeling and mass spectrometry (MS) confirmed the incorporation of a phenyllactate monomer derived from phenylalanine into the diketomorpholine scaffold.
• Acu-dioxomorpholine shows structural similarity to P-glycoprotein inhibitors, relevant for multidrug-resistant cancers.
• The identified biosynthetic pathway facilitates genome mining for related compounds.

Outlook:

• The FAC-MS platform can be applied to discover and characterize other fungal secondary metabolites.
• Further investigation into the C_R domain may reveal novel enzymatic mechanisms.
• This work opens avenues for developing new therapeutic agents targeting drug-resistant cancers.