Reductive Release from a Hybrid PKS-NRPS during the Biosynthesis of Pyrichalasin H

authored by: Henrike Heinemann, Haili Zhang, Russell J. Cox
Abstract: Three central steps during the biosynthesis of cytochalasan precursors, including reductive release, Knoevenagel cyclisation and Diels Alder cyclisation are not yet understood at a detailed molecular level. In this work we investigated the reductive release step catalysed by a hybrid polyketide synthase non-ribosomal peptide synthetase (PKS-NRPS) from the pyrichalasin H pathway. Synthetic thiolesters were used as substrate mimics for in vitro studies with the isolated reduction (R) and holo-thiolation (T) domains of the PKS-NRPS hybrid PyiS. These assays demonstrate that the PyiS R-domain mainly catalyses an NADPH-dependent reductive release of an aldehyde intermediate that quickly undergoes spontaneous Knoevenagel cyclisation. The R-domain can only process substrates that are covalently bound to the phosphopantetheine thiol of the upstream T-domain, but it shows little selectivity for the polyketide.
Organisation(s): Institute of Organic Chemistry
Centre of Biomolecular Drug Research (BMWZ)
Type: Article
Journal: Chemistry - a European journal
Volume: 30
No. of pages: 8
ISSN: 0947-6539
Publication date: 16.01.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Catalysis, General Chemistry, Organic Chemistry
Electronic version(s): https://doi.org/10.1002/chem.202302590 (Access: Open)

BibTeX

@article{a34bab20d9d54876a85c8544bac42717,
title = "Reductive Release from a Hybrid PKS-NRPS during the Biosynthesis of Pyrichalasin H",
abstract = "Three central steps during the biosynthesis of cytochalasan precursors, including reductive release, Knoevenagel cyclisation and Diels Alder cyclisation are not yet understood at a detailed molecular level. In this work we investigated the reductive release step catalysed by a hybrid polyketide synthase non-ribosomal peptide synthetase (PKS-NRPS) from the pyrichalasin H pathway. Synthetic thiolesters were used as substrate mimics for in vitro studies with the isolated reduction (R) and holo-thiolation (T) domains of the PKS-NRPS hybrid PyiS. These assays demonstrate that the PyiS R-domain mainly catalyses an NADPH-dependent reductive release of an aldehyde intermediate that quickly undergoes spontaneous Knoevenagel cyclisation. The R-domain can only process substrates that are covalently bound to the phosphopantetheine thiol of the upstream T-domain, but it shows little selectivity for the polyketide.",
keywords = "cytochalasan, non-ribosomal peptide, polyketide, reductive release, SDR",
author = "Henrike Heinemann and Haili Zhang and Cox, {Russell J.}",
note = "Funding Information: HH was funded by LUH. DFG Forschergruppe 5170 CytoLabs is also thanked for funding. H.Z. was funded by the China Scholarship Council (CSC 201506200065). Open Access funding enabled and organized by Projekt DEAL. ",
year = "2024",
month = jan,
day = "16",
doi = "10.1002/chem.202302590",
language = "English",
volume = "30",
journal = "Chemistry - a European journal",
issn = "0947-6539",
publisher = "Wiley-VCH Verlag",
number = "4",
}