Elucidation of the biosynthesis of the hydrazine containing compound negamycin – ENHANCE

Negamycin, a specialized metabolite of the hydrazine family, is produced by the actinobacterium Kitasatospora purpeofusca. In addition, two metabolites of the negamycin family, 3-epi-deoxynegamycin (3-Dneg) and leucyl-3-epi-deoxynegamycin (L-3-Dneg) produced by the actinobacterium Streptomyces goshikiensis, have been identified. Negamycin metabolites are pseudopeptides with hydroxy-ß-lysine as the central amino acid.
Negamycin (but not 3-Dneg and L-3-Dneg) possesses antibacterial activity, especially against bacteria from the ESKAPE list (Klebsiella pneumonia, Enterobacter sp. and Pseudomonas aeruginosa), for which new antibiotics are urgently needed. Its mode of action is based on binding to ribosomes via a novel mechanism, stimulating miscoding and inhibiting ribosome translocation. Moreover, like 3-Dneg and L-3-Dneg, it possesses stop-codon readthrough activity. Negamycin metabolites could therefore be used for the treatment of genetic diseases caused by mutations leading to in-frame stop codons (e.g. some forms of the Duchenne muscular dystrophy or cystic fibrosis). In this project, we aim to (i) identify the genes involve the biosynthesis of the metabolites of the negamycin family, (ii) elucidate the function of the encoded enzymes (iii) increase the production of negamycin metabolites in order to isolate quantities sufficient for biological studies and, (v) further investigate the antibacterial and readthrough activities of negamycin and its analogues toward nonsense mutations.