TY - JOUR

T1 - Reductive Release from a Hybrid PKS-NRPS during the Biosynthesis of Pyrichalasin H

AU - Heinemann, Henrike

AU - Zhang, Haili

AU - Cox, Russell J.

N1 - 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.

PY - 2024/1/16

Y1 - 2024/1/16

N2 - 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.

AB - 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.

KW - cytochalasan

KW - non-ribosomal peptide

KW - polyketide

KW - reductive release

KW - SDR

UR - http://www.scopus.com/inward/record.url?scp=85178107839&partnerID=8YFLogxK

U2 - 10.1002/chem.202302590

DO - 10.1002/chem.202302590

M3 - Article

C2 - 37926691

AN - SCOPUS:85178107839

VL - 30

JO - Chemistry - a European journal

JF - Chemistry - a European journal

SN - 0947-6539

IS - 4

M1 - e202302590

ER -