The course of the enigmatic iterative use of a polyketide synthase module was deduced from targeted domain inactivation in the aureothin assembly line. Mutational analyses revealed that the N-terminus of AurA is not involved in the iteration process, ruling out an ACP-ACP shuttle. Furthermore, an AurA(KS°, ACP°)-AurA(AT(0)) heterodimer proved to be nonfunctional, whereas aureothin production was restored in a ΔaurA mutant complemented with AurA(KS°)-AurA(ACP°). This finding supports a model according to which the ACP-bound polyketide intermediate is transferred back to the KS domain on the opposite PKS strand.
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http://dx.doi.org/10.1021/ja304454r | DOI Listing |
Microb Cell Fact
January 2025
Chair of Technical Biochemistry, Technische Universität Dresden, Bergstraße 66, 01069, Dresden, Germany.
Background: The biosynthesis of the natural product family of the polycyclic tetramate macrolactams (PoTeMs) employs an uncommon iterative polyketide synthase/non-ribosomal peptide synthetase (iPKS/NRPS). This machinery produces a universal PoTeM biosynthetic precursor that contains a tetramic acid moiety connected to two unsaturated polyene side chains. The enormous structural and hence functional diversity of PoTeMs is enabled by pathway-specific tailoring enzymes, particularly cyclization-catalyzing oxidases that process the polyene chains to form distinct ring systems, and further modifying enzymes.
View Article and Find Full Text PDFAntibiotics (Basel)
December 2024
Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Miklukho-Maklaya 16/10, Moscow 117997, Russia.
Irumamycin (Iru) is a complex polyketide with pronounced antifungal activity produced by a type I polyketide (PKS) synthase. Iru features a unique hemiketal ring and an epoxide group, making its biosynthesis and the structural diversity of related compounds particularly intriguing. In this study, we performed a detailed analysis of the biosynthetic gene cluster (BGC) to uncover the mechanisms underlying Iru formation.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2024
TU Dresden: Technische Universitat Dresden, Faculty of Chemistry and Food Chemistry, Bergstraße 66, 01069, Dresden, GERMANY.
Polycyclic tetramate macrolactams (PoTeMs) represent a growing class of bioactive natural products that are derived from a common tetramate polyene precursor, lysobacterene A, produced by an unusual bacterial iterative polyketide synthase (PKS) / non-ribosomal peptide synthetase (NRPS). The structural and functional diversity of PoTeMs is biosynthetically elaborated from lysobacterene A by pathway-specific cyclizing and modifying enzymes. This results in diverse core structure decoration and cyclization patterns.
View Article and Find Full Text PDFACS Catal
November 2024
School of Chemistry, The University of Edinburgh, Edinburgh EH9 3FJ, U.K.
In nature, thousands of diverse and bioactive polyketides are assembled by a family of multifunctional, "assembly line" enzyme complexes called polyketide synthases (PKS). Since the late 20th century, there have been several attempts to decode, rearrange, and "reprogram" the PKS assembly line to generate valuable materials such as biofuels and platform chemicals. Here, the first module from () PKS12, an unorthodox, "modularly iterative" PKS, was modified and repurposed toward the formation of 2-methyl Guerbet lipids, which have wide applications in industry.
View Article and Find Full Text PDFChem Commun (Camb)
November 2024
Department of Chemistry, University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, UK.
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