Non-ribosomal Peptide Synthetases


Background


Non-ribosomal peptide synthetases (NRPSs) are large enzymes that generate a variety of important natural products, from antibiotics to immunosuppressants. In fact, a majority of drugs in clinical use today were inspired by non-ribosomal peptide or polyketide natural products, discovered from environmental sources. These modular enzymes function like an assembly line, selecting and incorporating specific (and frequently non- proteinogenic) amino acids into a growing peptide chain. This modular structure offers promise for re-engineering NRPS units to generate new useful products, but progress has to date been limited by the complex and dynamic nature of key domains, and a failure to define generally applicable “rules” to guide engineering efforts. NRPS research in the Ackerley lab explores ways to overcome these hurdles, aiming to re-engineer NRPS biosynthetic gene clusters to produce novel natural products with useful bioactivities, or superior drug leads.

NRPS Figure
Above: Depicted are the biosynthetic gene clusters (blue arrows) and their encoded NRPS assembly lines involved in the biosynthesis of pyoverdine (a), and the corresponding chemical structure for pyoverdine (b). The NRPS module Pa11 is highlighted in blue in a, as is the corresponding L-Thr residue that it incorporates into pyoverdine in b. NRPS domains are labelled as follow: ACL acyl-CoA ligase, C condensation, A adenylation, T thiolation, E epimerisation, and Te thioesterase. The following non-standard amino acid abbreviations are used: Dab, 2,4-diaminobutyric acid; fhOrn, N5-formyl-N5-hydroxyornithine; Orn, ornithine. 


Research Projects


NRPS Engineering

 

Combinatorial biosynthesis of natural products

 

Heterologous expression of biosynthetic gene clusters