Quartromicin biosynthesis: two alternative polyketide chains produced by one polyketide synthase assembly line.

Area of Science:

• Natural Product Biosynthesis
• Molecular Biology
• Biochemistry

Background:

• Quartromicins are unique antiviral compounds belonging to the spirotetronate natural product family.
• Understanding their biosynthesis is crucial for developing novel antiviral agents.

Purpose of the Study:

• To identify the biosynthetic gene cluster responsible for quartromicin production.
• To elucidate the mechanism of tetronate ring formation and polyketide chain generation.

Main Methods:

• Degenerate primer PCR amplification was used to identify key genes in the biosynthetic pathway.
• In vitro reconstruction experiments were performed to confirm biochemical steps.
• Analysis of polyketide synthase (PKS) assembly line strategies.

Main Results:

• The biosynthetic gene cluster for quartromicins was successfully identified.
• Biochemical assays confirmed the incorporation of 1,3-bisphosphoglycerate into the tetronate ring.
• Evidence for a module skipping strategy in polyketide synthesis was observed, leading to alternative product formation.

Conclusions:

• The study provides a foundational understanding of quartromicin biosynthesis.
• The findings shed light on the stereodivergent intermolecular cyclization and C2 symmetric molecule construction.
• This work opens avenues for future research into natural product drug discovery and synthetic biology.