Engineering Atypical Tetracycline Formation in Amycolatopsis sulphurea for the Production of Modified Chelocardin Antibiotics

• DOI: 10.1021/acschembio.8b01125
• Publication Date: 2019-02-12T17:31:07Z
• Authors: Tadeja Lukežič; Antoine Abou Fayad; Chantal Bader; Kirsten Harmrolfs; Johannes Bartuli; Sebastian Groß; Urška Lešnik; Fabienne Hennessen; Jennifer Herrmann; Špela Pikl; Hrvoje Petković; Rolf Müller
• Keywords: 0301 basic medicine; 0303 health sciences; Glycosylation; Molecular Structure; Stereoisomerism; Methyltransferases; Microbial Sensitivity Tests; Streptomyces; Anti-Bacterial Agents; Structure-Activity Relationship; 03 medical and health sciences; Tetracyclines; Actinomycetales; Drug Discovery; Mutation; Polyketide Synthases; Transaminases

To combat the increasing spread of antimicrobial resistance and shortage novel anti-infectives, one strategy for development new antibiotics is to optimize known chemical scaffolds. Here, we focus on biosynthetic engineering Amycolatopsis sulphurea derivatization atypical tetracycline chelocardin its potent broad-spectrum derivative 2-carboxamido-2-deacetyl-chelocardin. Heterologous genes were introduced into this producer modify functional groups generate derivatives. We demonstrate cooperation polyketide synthase with tailoring enzymes involved in biosynthesis oxytetracycline from Streptomyces rimosus. An interesting feature chelocardin, compared oxytetracycline, opposite stereochemistry C4 amino group. Genes transamination N,N-dimethylation heterologously expressed an A. mutant lacking C4-aminotransferase. Chelocardin derivatives group, as N,N-dimethyl-epi-chelocardin N,N-dimethyl-2-carboxamido-2-deacetyl-epi-chelocardin, produced only when aminotransferase was coexpressed N-methyltransferase OxyT. Surprisingly, OxyT exclusively accepted intermediates carrying S-configured group at chelocardin. Applying medicinal chemistry approaches, several 2-carboxamido-2-deacetyl-epi-chelocardin modified produced. Analysis activities compounds demonstrated that primary amine R configuration a crucial structural activity Unexpectedly, C10 glycosylated analogues identified, thus revealing glycosylation potential sulphurea. However, efficient backbone occurred after dimethylated position S configuration, which suggests some evolutionary remains glycosylation.