Translating protein enzymes without aminoacyl-tRNA synthetases

Protein translation from the ribosome seemingly requires dozens of sophisticated aminoacyl-tRNA synthetases (aaRSs). Despite the discovery of tRNA-aminoacylating ribozymes, such as the flexizyme, synthesizing protein enzymes from highly simplified translation systems in the absence of aaRS remains undemonstrated. Here, we show the translation of multiple protein enzymes of distinct functions using solely flexizyme-charged tRNAs, through improving the translation yield by concentrating cation-depleted tRNAs. Notably, we used the aaRS-free translation system to produce an active aaRS (TrpRS), which in turn catalyzed the charging of more tRNAs. Moreover, toward realizing mirror-image translation, we performed the mirror-image tRNA charging with D-amino acids by a synthetic L-flexizyme. Our work demonstrates the feasibility of translating protein enzymes from a highly simplified translation apparatus without aaRS and drastically reduces the requirement to chemically synthesize dozens of large aaRS proteins for realizing mirror-image translation.

Automated summary

The study demonstrates the feasibility of translating protein enzymes without the need for aaRS using flexizyme-charged tRNAs, and successfully produced an active aaRS in the process. This research has made progress in achieving mirror-image translation.