Discovery of Tetronate-Containing Kongjuemycins from a Coral-Associated Actinomycete and Elucidation of Their Biosynthetic Origin.

Tetronate antibiotics make up a growing family of natural products with a wide variety of biological activities. Herein, we report four new tetronates kongjuemycins (KJMs, 5 - 8 ) from a coral-associated actinomycete Pseudonocardia kongjuensis SCSIO 11457, and the identification and characterization of the KJM biosynthetic gene cluster ( kjm ) by heterologous expression, comparative genomic analysis, isotope labeling, and gene knockout studies. The biosynthesis of KJMs is demonstrated to harness diverse precursors from primary metabolism for building secondary metabolites.