Researchers at the University of Tokyo and RIKEN have developed a groundbreaking method to synthesize all 21 types of transfer RNA (tRNA) simultaneously in vitro, marking a significant step toward creating self-replicating artificial molecular systems.

This achievement overcomes a major technical barrier by enabling the production of all tRNA types, complementing previous success in reproducing the 20 aminoacyl-tRNA synthetases essential for protein synthesis, bringing us closer to a complete, self-sustaining protein synthesis system in vitro.

Such synthetic systems could surpass natural organisms in stability, scalability, and customizability, with promising applications in pharmaceuticals, industrial enzymes, and bespoke biomolecules.

The platform developed is expected to evolve into a versatile, cell-like environment for studying molecular biology outside living cells, with broad implications for biofabrication and synthetic life research.

This method facilitates the incorporation of non-standard amino acids into proteins, advancing protein engineering and expanding the genetic code, while also simplifying genetic modifications for artificial proteins and peptides.

This milestone supports the broader goal of constructing life-like molecular machines capable of reproducing their components, providing valuable insights into the origins of life and evolution.

The breakthrough addresses a major challenge in synthetic biology by enabling the creation of artificial systems capable of self-reproduction, which could lead to more stable and controllable production platforms for pharmaceuticals and food.

Future developments aim to add more genes to this system, increasing its complexity and functionality, potentially surpassing natural biological systems in design flexibility.

The transcribed tRNAs are processed into mature, functional molecules using HDV ribozyme and RNase P enzymes, streamlining the production process and eliminating the need for individual handling and purification.

The new 'tRNA array method' involves encoding all tRNA genes for the 20 amino acids on a single DNA plasmid, transcribing them collectively, and then using HDV ribozyme and RNase P to isolate individual tRNAs for direct use in protein translation.

This research was published in Nature Communications on August 26, 2025, under the title 'Simultaneous in vitro expression of minimal 21 transfer RNAs by tRNA array method,' highlighting its significance in synthetic biology.

The advancements also open pathways for incorporating non-natural amino acids into proteins, paving the way for novel artificial peptides and proteins with unique properties.