A Unique Mechanism for Methyl Ester Formation via an Amide Intermediate Found in Myxobacteria
| Autor: | Birgitte Kunze, Inga Müller, Rolf Müller, Sheeba Veluthoor, Taifo Mahmud, Heinrich Steinmetz, Stefan Weinig |
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| Rok vydání: | 2006 |
| Předmět: |
Methyl Ethers
Stereochemistry Molecular Sequence Data Biology Biochemistry chemistry.chemical_compound Biosynthesis Amide Moiety Myxococcales Stigmatella aurantiaca Molecular Biology Chromatography High Pressure Liquid chemistry.chemical_classification Molecular Structure Sequence Homology Amino Acid Myxothiazol Organic Chemistry biology.organism_classification Amides Amino acid Thiazoles Acrylates chemistry Glycine Methacrylates Molecular Medicine Heterologous expression Polyketide Synthases Sequence Alignment |
| Zdroj: | ChemBioChem. 7:1197-1205 |
| ISSN: | 1439-4227 |
| Popis: | Secondary metabolism involves a broad diversity of biochemical reactions that result in a wide variety of biologically active compounds. Terminal amide formation during the biosynthesis of the myxobacterial electron-transport inhibitor, myxothiazol, was analyzed by heterologous expression of the unique nonribosomal-peptide synthetase, MtaG, and incubation with a synthesized substrate mimic. These experiments provide evidence that the terminal amide is formed from a carrier protein-bound myxothiazol acid that is thioesterified to MtaF. This intermediate is transformed to an amide by extension with glycine and subsequent oxidative cleavage by MtaG. The final steps of melithiazol assembly involve a highly similar protein-bound intermediate (attached to MelF, a homologue of MtaF), which is transformed to an amide by MelG (homologue of MtaG). In this study, we also show that the amide moiety of myxothiazol A can be hydrolyzed in vivo to the formerly unknown free myxothiazol acid by heterologous expression of melJ in the myxothiazol producer Stigmatella aurantiaca DW4/3-1. The methyltransferase MelK can finally methylate the acid to give rise to the methyl ester, which is produced as the final product in the melithiazol A biosynthetic pathway. These experiments clarify the role of MelJ and MelK during melithiazol assembly. |
| Databáze: | OpenAIRE |
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