Biosynthesis of methyl-proline containing griselimycins, natural products with anti-tuberculosis activity. Issue 11 (21st September 2017)

• Record Type: Journal Article
• Authors: Lukat, Peer; Katsuyama, Yohei; Wenzel, Silke; Binz, Tina; König, Claudia; Blankenfeldt, Wulf; Brönstrup, Mark; Müller, Rolf
• Is Part Of: Chemical science. Volume 8:Issue 11(2017)
• Page Start: 7521
• Page End: 7527
• Publication Date: 2017-09-21
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c7sc02622f
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : The biosynthesis of griselimycins in Streptomyces DSM 40835 and the pathway that stereospecifically convertsl -leucine to (2 S, 4 R )-4-methyl-proline are reported by means of biochemical and structural analysis. Abstract : Griselimycins (GMs) are depsidecapeptides with superb anti-tuberculosis activity. They contain up to three (2 S, 4 R )-4-methyl-prolines (4-MePro), of which one blocks oxidative degradation and increases metabolic stability in animal models. The natural congener with this substitution is only a minor component in fermentation cultures. We showed that this product can be significantly increased by feeding the reaction with 4-MePro and we investigated the molecular basis of 4-MePro biosynthesis and incorporation. We identified the GM biosynthetic gene cluster as encoding a nonribosomal peptide synthetase and a sub-operon for 4-MePro formation. Using heterologous expression, gene inactivation, and in vitro experiments, we showed that 4-MePro is generated by leucine hydroxylation, oxidation to an aldehyde, and ring closure with subsequent reduction. The crystal structures of the leucine hydroxylase GriE have been determined in complex with substrates and products, providing insight into the stereospecificity of the reaction.