Biosynthesis at the Intersection of Primary and Specialized Metabolism: the α-Ketoacid Dehydrogenase Example (BiosynKADH)

• Applicants: Professor Dr. Helge Björn Bode; Professor Dr. Andriy Luzhetskyy
• Subject Area: Biological and Biomimetic Chemistry
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 545768238

Multiple bacterial natural products including the pepteridine virulence factors and the therapeutically-relevant antibiotic virginiamycin M, are biosynthesized at the intersection between primary and specialized metabolism. In these cases, primary metabolic alpha-ketoacid dehydrogenase complexes (KADHs) provide essential acyl building blocks to multienzyme complexes of specialized metabolism, including modular polyketide synthases (PKSs) and non-ribosomal peptide synthetases (NRPSs). More remarkably, in certain pathways, the KADH components are fully integrated into the PKS/NRPS mega-enzymes. At present, nothing is known about the sequence, mechanistic and architectural adaptations that were required relative to the ancestral KADHs to afford such chimaeras - information which is necessary for creating novel types of hybrids in the laboratory by genetic engineering. In this context, the present German-French collaborative project aims to investigate this type of system in detail. Specifically, we will: (i) generate an exhaustive catalog of specialized metabolic pathways that incorporate KADH machinery using genome mining; (ii) structurally characterize the products of newly-identified systems by heterologous expression; (iii) use ancestral protein reconstruction to propose a reasonable evolutionary trajectory to present day KADH enzymes; (iv) deploy an integrative structural biology approach to elucidate key architectural features of multienzyme-integrated KADHs (i.e. oligomerization state, stoichiometry of KADH component binding, and interactions with partner domains within the multienzymes); and (v) exploit the obtained fundamental insights to genetically engineer biosynthetic systems, towards the goal of generating bespoke natural product analogs bearing KADH-derived moieties. This project follows on from previous successful collaboration between three of the partner laboratories, and is fully anchored in all groups’ strong, highly-complementary expertise.

• DFG Programme: Research Grants
• International Connection: France
• Partner Organisation: Agence Nationale de la Recherche / The French National Research Agency
• Co-Investigator: Dr. Georg Hochberg
• Cooperation Partners: Dr. Yanyan Li; Professorin Kira J. Weissman, Ph.D.