Resistance Gene-Guided Genome Mining Reveals RPL10 as the Target of Ligustrone A

The ribosome is essential for protein synthesis and targeting its function serves as a platform for many therapies. Resistance gene-guided genome mining for <i>a priori</i> target identification has emerged as a useful workflow in natural product drug discovery, allowing for identification of a compound's target before the time-consuming work of isolation and characterization is performed. In this work, we identify the previously unknown <i>lig</i> biosynthetic gene cluster (BGC) which contains a predicted resistance gene that shares sequence identity with the gene for human ribosomal protein RPL10. Through both heterologous expression and <i>in situ</i> BGC engineering, we identify ligustrone A (<b>1</b>) as this BGC's product. Utilizing chemical genetics and chemoproteomics, we validate that <b>1</b> engages RPL10. Taken together, via resistance gene-guided mining we both discover a new target for a known natural product and elucidate its biosynthesis.