Evolution of the biosynthesis of thiazolyl-indole metabolites in bacteria and plants

ERICH GLAWISCHNIG
Lehrstuhl für Genetik
Technische Universität München
Am Hochanger 8
D-85350 Freising
egl@wzw.tum.de
http://www.wzw.tu-muenchen.de/genetik/Research-Glawischnig.html

To study secondary metabolism in distantly related organisms, the biosynthesis of the thiazolyl-indole metabolites camalexin (the Arabidopsis phytoalexin) and BE-10988 (a tumour-inhibitory compound isolated from a Streptomyces strain) is comparatively investigated. Camalexin is synthesized from Tryptophan and Cystein and two cytochrome P450 reactions, catalyzed by CYP79B2 and CYP71B15 have been characterized. In the biosynthesis of BE-10988 we have identified two candidate genes, a cytochrome P450 gene and a non-ribosomal peptide synthetase (NRPS) as targets for the isolation of a biosynthetic gene cluster. Knock-out mutants in candidate genes will clarify their role in the pathway and currently a conjugation system is established. When the BE-10988 biosynthetic pathway is identified a comparison with camalexin biosynthesis will show, whether homologous genes have been recruited or structural and mechanistic features are shared between independently evolved enzymes.

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