A new synthetic biology system for investigating the biosynthesis of antibiotics and other secondary metabolites in streptomycetes.

We have created a novel synthetic biology expression system allowing easy refactoring of biosynthetic gene clusters (BGCs) as monocistronic transcriptional units. The system is based on a set of plasmids containing a strong kasOp* promoter, RBS and terminators. It allows the cloning of biosynthetic genes into transcriptional units kasOp*-gene(s)-terminator flanked by several rare restriction cloning sites that can be sequentially combined into the artificial BGC in three compatible Streptomyces integration vectors. They allow a simultaneous integration of these BGCs at three different attB sites in the Streptomyces chromosome. The system was validated with biosynthetic genes from two known BGCs for aromatic polyketides landomycin and mithramycin.