Identification of the 216kbp gene cluster and structure elucidation of gargantulides B and C, new complex 52-membered macrolides from Amycolatopsis sp.

Carretero-Molina, D.; Ortiz-Lopez, F. J.; Gren, T.; Oves-Costales, D.; Martin, J.; Roman-Hurtado, F.; Jorgensen, T. S.; de la Cruz, M.; Diaz, C.; Vicente, F.; Blin, K.; Reyes, F.; Weber, T.; Genilloud, O.

doi:10.1101/2021.08.11.455926

bioRxiv · 10.1101/2021.08.11.455926

Identification of the 216kbp gene cluster and structure elucidation of gargantulides B and C, new complex 52-membered macrolides from Amycolatopsis sp.

Carretero-Molina, D.·Ortiz-Lopez, F. J.·Gren, T.·Oves-Costales, D.·Martin, J.·Roman-Hurtado, F.·Jorgensen, T. S.·de la Cruz, M.·Diaz, C.·Vicente, F.·Blin, K.·Reyes, F.·Weber, T.·Genilloud, O.

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Abstract

Gargantulides B and C, two new and highly complex 52-membered glycosylated macrolactones, were isolated from Amycolatopsis sp. strain CA-230715 during an antibacterial screening campaign. The structures of these giant macrolides were elucidated by 2D NMR spectroscopy and shown to be related to gargantulide A, although containing additional {beta}-glucopyranose and/or -arabinofuranose monosaccharides separately attached to their backbones. Genome sequencing allowed the identification of a strikingly large 216 kbp biosynthetic gene cluster, among the largest type I PKS clusters described so far, and the proposal of a biosynthetic pathway for gargantulides A-C. Additionally, genes putatively responsible for the biosynthesis of the amino sugar {beta}-3,6-deoxy-3-methylamino glucose, reported exclusively in gargantulide macrolides, were also found in the cluster and described in this work. The absolute configurations of gargantulides B and C were assigned based on a combination of NMR and bioinformatics analysis of ketoreductase and enoylreductase domains within the multimodular type I PKS. Furthermore, the absolute stereochemistry of the related macrolide gargantulide A has now been revised and completed. Gargantulides B and C display potent antibacterial activity against a set of drug-resistant Gram-positive bacteria and moderate activity against the clinically relevant Gram-negative pathogen Acinetobacter baumannii.

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Carretero-Molina, D., Ortiz-Lopez, F. J., Gren, T., Oves-Costales, D., Martin, J., Roman-Hurtado, F., Jorgensen, T. S., de la Cruz, M., Diaz, C., Vicente, F., Blin, K., Reyes, F., Weber, T., Genilloud, O.. 2021-08-11. Identification of the 216kbp gene cluster and structure elucidation of gargantulides B and C, new complex 52-membered macrolides from Amycolatopsis sp.. https://doi.org/10.1101/2021.08.11.455926

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