Aminoacyl-tRNA-dependent enzymes in natural product biosynthesis: structure-function insights

Aminoacyl-tRNAs, charged by aminoacyl-tRNA synthetases with cognate amino acids, are essential for protein synthesis in primary metabolism. Beyond this canonical role, increasing evidence highlights their involvement in natural product biosynthesis. In this review, we first describe the biosynthesis of the aminoacyl nucleoside sulfamate ascamycin from Streptomyces sp. 80H647, highlighting the discovery of the alanyl-tRNA synthetase-like enzyme AcmF through an AI-driven "Forecasting Biosynthesis" approach. Leveraging recent advances in AlphaFold 3, we constructed complex models of a broadened repertoire of aminoacyl-tRNA-dependent enzymes to provide preliminary structure-function insights. These include the isoleucyl-tRNA synthetase-like enzyme SbzA, Gcn5-related N-acetyltransferase-fold transferases, cyclodipeptide synthase family enzymes, and lantibiotic dehydratase-like peptide aminoacyl-tRNA ligases. The catalytic mechanisms of these aminoacyl-tRNA-dependent enzymes are summarized in detail in this review.