Grant: Project Grant

Nonribosomal peptide synthetases (NRPSs) are large microbial enzymes that catalyze peptide bond formation. Instead of making proteins like the ribosome does, these megaenzymes produce a vast variety of small molecules with important biological activity, such as antifungals, antibacterials, antivirals, antitumours, immunosuppressants, and green chemicals. These NRPS products have revolutionized human health: Penicillin, cyclosporin, cephalosporin and daptomycin have saved tens of millions of lives worldwide. NRPSs are true macromolecular machines, huge proteins with multiple active sites, moving parts and a coordinated production cycle. They consist of a series of multidomain modules, with each module responsible for adding one specific amino acid to the growing peptide molecule, in assembly line fashion. The focus of this research is to expand the structural knowledge of nonribosomal peptide synthetases and the mechanisms they employ to synthesize bio-active molecules. We will use chemical biology, biochemistry, biophysics and structural biology, including X-ray crystallography and cryo-electron microscopy, to characterize NRPSs and determine their three-dimensional structures at different points in the process of making different natural products. We will address a range of questions, including elucidating the precise details of how building blocks are chemically assembled into the peptide products, how peptides are modified to gain proper function and how the NRPSs perform the gymnastics and large-scale rearrangements they need to perform to create these green chemicals and therapeutics. The wide-ranging activities of NRPS small molecule products, combined with the potential to engineer NRPSs to produce novel bio-active molecules, make them a promising source of new therapeutics. Our studies further fundamental understanding of these vast and complex enzymes and potentiate their bioengineering.