Biosynthetic strategies for tetramic acid formation.

Covering: up to the end of 2020Natural products bearing tetramic acid units as part of complex molecular architectures exhibit a broad range of potent biological activities. These compounds thus attract significant interest from both the biosynthetic and synthetic communities. Biosynthetically, most of the tetramic acids are derived from hybrid polyketide synthase (PKS) and nonribosomal peptide synthetase (NRPS) machineries. To date, over 30 biosynthetic gene clusters (BGCs) involved in tetramate formation have been identified, from which different biosynthetic strategies evolved in Nature to assemble this intriguing structural unit were characterized. In this Highlight we focus on the biosynthetic concepts of tetramic acid formation and discuss the molecular mechanism towards selected representatives in detail, providing a systematic overview for the development of strategies for targeted tetramate genome mining and future applications of tetramate-forming biocatalysts for chemo-enzymatic synthesis.