Download MendeleyEnzymatic Pyridine Aromatization during Thiopeptide Biosynthesis.
Rice, A.J., Pelton, J.M., Kramer, N.J., Catlin, D.S., Nair, S.K., Pogorelov, T.V., Mitchell, D.A., Bowers, A.A.(2022) J Am Chem Soc 144: 21116-21124
- PubMed: 36351243
- DOI: https://doi.org/10.1021/jacs.2c07377
- Primary Citation of Related Structures:
8EJY, 8EJZ - PubMed Abstract:
Thiazole-containing pyritides (thiopeptides) are ribosomally synthesized and post-translationally modified peptides (RiPPs) that have attracted interest owing to their potent biological activities and structural complexity. The class-defining feature of a thiopeptide is a six-membered, nitrogenous heterocycle formed by an enzymatic [4 + 2]-cycloaddition. In rare cases, piperidine or dehydropiperidine (DHP) is present; however, the aromatized pyridine is considerably more common. Despite significant effort, the mechanism by which the central pyridine is formed remains poorly understood. Building on our recent observation of the Bycroft-Gowland intermediate (i.e., the direct product of the [4 + 2]-cycloaddition), we interrogated thiopeptide pyridine synthases using a combination of targeted mutagenesis, kinetic assays, substrate analogs, enzyme-substrate cross-linking, and chemical rescue experiments. Collectively, our data delineate roles for several conserved residues in thiopeptide pyridine synthases. A critical tyrosine facilitates the final aromatization step of pyridine formation. This work provides a foundation for further exploration of the [4 + 2]-cycloaddition reaction and future customization of pyridine-containing macrocyclic peptides.
Organizational Affiliation:
Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, United States.
