Thiotemplated biosynthesis of bacterial polyyne fatty acids by a designated desaturase tiad.

Kim HJ, Ishida K, Hertweck C (2022) Thiotemplated biosynthesis of bacterial polyyne fatty acids by a designated desaturase tiad. ChemBioChem 23(21), e202200430.

Abstract

Various bacterial species are capable of producing highly modified fatty acid derivatives with conjugated triple bonds, which play important ecological roles as antifungals and toxins in mutualistic and pathogenic interactions. Furthermore, the terminal polyyne moiety is of interest as pharmacophore and as tag in bioorthogonal chemistry and live imaging. To gain insight into the assembly of these highly reactive natural products, we investigated tetrayne (caryoynencin and protegencin) biosynthesis genes from Trinickia caryophylli and Pseudomonas protegens. Pathway dissection and reconstitution in the heterologous host Burkholderia graminis revealed the genes minimally required for polyyne formation. Mutational analyses and biochemical assays demonstrated that polyyne biosynthesis is thiotemplated, involving a fatty acyl-AMP ligase, a designated acyl carrier protein, and a thioesterase. Heterologous expression of pointmutated desaturase genes showed that three desaturases work synergistically to introduce four triple bonds. These findings point to an intricate desaturase complex and provide important information for future bioengineering experiments.

Leibniz-HKI-Autor*innen

Christian Hertweck
Keishi Ishida
Hak Joong Kim

Identifier

doi: 10.1002/cbic.202200430

PMID: 36107027