8EJZ

[4+2] Aza-Cyclase Y293F variant

Summary for 8EJZ

• Entry DOI: 10.2210/pdb8ejz/pdb
• Related: 8EJY
• Descriptor: PbtD (2 entities in total)
• Functional Keywords: enzyme, thiopeptide, ripp, biosynthesis., antibiotic
• Biological source: Planobispora rosea
• Total number of polymer chains: 2
• Total formula weight: 74199.59

Authors

Nair, S.K. (deposition date: 2022-09-19, release date: 2022-11-23, Last modification date: 2023-10-25)

Primary citation

Rice, A.J.,Pelton, J.M.,Kramer, N.J.,Catlin, D.S.,Nair, S.K.,Pogorelov, T.V.,Mitchell, D.A.,Bowers, A.A.
Enzymatic Pyridine Aromatization during Thiopeptide Biosynthesis.
J.Am.Chem.Soc., 144:21116-21124, 2022

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.

PubMed: 36351243
DOI: 10.1021/jacs.2c07377

Experimental method

X-RAY DIFFRACTION (1.7 Å)