UC Berkeley

Amino acids are one of nature’s privileged scaffolds for chemical and biomolecular diversification. Beyond the standard twenty amino acids used in protein synthesis, hundreds more noncanonical amino acids (ncAAs) have been found in natural products with useful chemical features. Here we present a resistance-guided approach to discovering ncAA natural products with an emerging class of enzymes: tRNA-deacylases (tRDs). Beginning with the discovery and characterization of a tRD with specificity towards a ncAA, we performed family-wide analyses of tRDs in biosynthetic gene clusters (BGCs) and established tRDs as a widely present genomic marker of ncAA metabolism. These efforts enabled us to discover and elucidate biosynthetic pathways for several new ncAAs and natural products. Through strategies like protein engineering and cascade design, we employed several of these enzymes as biocatalysts to achieve transformations that have been challenging to access otherwise. We anticipate the advances in genome mining and experimental characterization developed in this work will have broad applications for discovering new natural products with ncAAs and useful biocatalysts.