High-throughput engineering of ligand-activated splicing ribozyme through domain insertion.

Domain insertion is an established method to engineer ligand-mediated control of activity in protein scaffolds. Whether this strategy can be systematically applied to large, structured RNAs remains unclear. In this study, we investigated the feasibility of engineering ligand-activated splicing ribozymes (LASRs) from group I catalytic introns. Using domain-insertion profiling coupled with high-throughput screening, we mapped the nucleotide-resolution landscape of aptamer insertion across the ribozyme and identified sites that support robust ligand-dependent control. We showed LASRs function across multiple kingdoms of life, including diverse species of bacteria and even fungi, and can be used to regulate various genetic outputs. Finally, we integrated LASRs with a genetic recorder that writes information into ribosomal RNA, enabling sequencing-based recovery of intracellular chemical signals from microbial consortia. This work establishes LASRs as an RNA-based inducible control platform for sensing diverse chemical inputs, regulating the expression of diverse genes of interest, and recording intracellular information.