Bacterial pathogen channels medium-sized fatty acids into malleicyprol biosynthesis.

Trottmann F, Fiedler J, Ishida K, Ishida-Ito M, Little RF, Hertweck C (2023) Bacterial pathogen channels medium-sized fatty acids into malleicyprol biosynthesis. ACS Chem Biol 18(7), 1557-1563.


Bacterial pathogens of the Burkholderia pseudomallei (BP) group cause life-threatening infections in both humans and animals. Critical for the virulence of these often antibiotic-resistant pathogens is the polyketide hybrid metabolite malleicyprol, which features two chains, a short cyclopropanol-substituted chain and a long hydrophobic alkyl chain. The biosynthetic origin of the latter has remained unknown. Here, we report the discovery of novel overlooked malleicyprol congeners with varied chain lengths and identify medium-sized fatty acids as polyketide synthase (PKS) starter units that constitute the hydrophobic carbon tails. Mutational and biochemical analyses show that a designated coenzyme A-independent fatty acyl-adenylate ligase (FAAL, BurM) is essential for recruiting and activating fatty acids in malleicyprol biosynthesis. In vitro reconstitution of the BurM-catalyzed PKS priming reaction and analysis of ACP-bound building blocks reveal a key role of BurM in the toxin assembly. Insights into the function and role of BurM hold promise for the development of enzyme inhibitors as novel antivirulence therapeutics to combat infections with BP pathogens.


Jonas Fiedler
Christian Hertweck
Keishi Ishida
Mie Ishida-Ito
Rory Little
Felix Trottmann


doi: 10.1021/acschembio.3c00188

PMID: 37319349