The gene cluster in Streptomyces calvus associated with the biosynthesis of the fluoro- and sulfamyl-metabolite nucleocidin was interrogated by systematic gene knockouts. Out of the 26 gene deletions most did not affect fluorometabolite production, nine abolished sulfamylation but not fluorination, and three precluded fluorination, having no effect on sulfamylation. In addition to nucI, nucG, nucJ, nucK, nucL, nucN, nucO, nucQ and nucP we identified two genes (nucW, nucA), belonging to a phosphoadenosine phosphosulfate (PAPS) gene cluster, as required for sulfamyl assembly. Three genes (orf(-3), orf2 and orf3) were found to be essential for fluorination, although the activities of their protein products are unknown. These genes as well as nucK, nucN, nucO and nucPNP, whose knockouts produced results differing from those described in a recent report, were also deleted in Streptomyces virens - with confirmatory outcomes. This genetic profile should inform biochemistry aimed at uncovering the enzymology behind nucleocidin biosynthesis.
We thank the EPSRC, Leverhulme Trust and the EU Horizon 2020 Sinfonia consortia for financial support. The Chinese Scholarship Council is acknowledged for studentship support (Y.C.). We also thank Pfizer Ltd., (Groton, USA) for supplying the nucleocidin-producing strain S. calvus T-3018.
Leverhulme Trust. Grant Number: RPG-2021-028
Chinese Scholarship Council
Engineering and Physical Sciences Research Council
Data Availability StatementThe data that support the findings of this study are available in the supplementary material of this article.
- fluorometabolite biosynthesis
- gene knockouts
- natural products