A1 Refereed original research article in a scientific journal

Three-Enzyme Cascade Catalyzes Conversion of Auramycinone to Resomycin in Chartreusin Biosynthesis




AuthorsNiemczura, Magdalena; Nuutila, Aleksi; Wang, Rongbin; Rauhanen, Katariina; Nybo, S. Eric; Metsä-Ketelä, Mikko

PublisherAmerican Chemical Society (ACS)

Publishing placeWASHINGTON

Publication year2025

JournalACS Chemical Biology

Journal name in sourceACS Chemical Biology

Journal acronymACS CHEM BIOL

Volume20

Issue7

First page 1457

Last page1463

Number of pages7

ISSN1554-8929

eISSN1554-8937

DOIhttps://doi.org/10.1021/acschembio.5c00205

Web address https://doi.org/10.1021/acschembio.5c00205

Self-archived copy’s web addresshttps://research.utu.fi/converis/portal/detail/Publication/499245790


Abstract
Chartreusin is a potent antiproliferative agent that contains a unique aromatic pentacyclic bislactone carbon scaffold. The biosynthesis of type II polyketide aglycone has been extensively investigated and shown to proceed through a tetracyclic anthracycline intermediate. The last remaining unknown steps are the conversion of auramycinone to resomycin C. Here we have discovered three enzymes that play crucial roles in two mechanistically distinct dehydration reactions. We show that ChaX is an NAD(P)H-dependent auramycinone quinone reductase that allows the cyclase-like ChaU to catalyze the formation of 9,10-dehydroauramycinone via a carbanion intermediate. In contrast, the cyclase-like ChaJ, homologous to ChaU, is responsible for subsequent 7,8-dehydration via a canonical carbocation intermediate, yielding resomycin C. The results were confirmed via assembly of the biosynthetic pathway for production of resomycin C in Streptomyces coelicolor M1152 Delta matAB. The work expands the catalytic repertoire of the SnoaL protein family, which has previously been associated with anthracycline fourth-ring cyclization and two-component 1-hydroxylation.

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Funding information in the publication
The authors would like to acknowledge funding from the Academy of Finland (Grant Nos. 340013 and 354998 to M.M.- K.), the National Science Foundation (Grant Nos. ENG-2015951, ENG-2321976, and CHE-2348596 to S.E.N.) and the Turku University Foundation (to M.N.).


Last updated on 2025-13-08 at 13:26