In vitro translation study using single molecule fluorescence resonance energy transfer

Single molecule fluorescence resonance energy transfer (FRET) reveals the mechanism of tRNA selection by ribosome. In biological protein synthesis, or translation, a ribosome selects correct tRNAs according to the genetic code written on an mRNA with an unusually low error frequency (1/10,000). Single molecule study showed that a correct tRNA has slightly stronger interaction with the mRNA than an incorrect tRNA, resulting in tighter binding to the ribosome. Results further suggest that a small difference in the initial tRNA-mRNA interaction induces a significant difference in the fluctuation of the system to proceed to the next step. Only correct tRNA-mRNA interaction often leads the system to the correct pathway to the next step with a high energy barrier, i.e. GTP hydrolysis. Such induction process overcoming a high energy barrier is found to be critical in explaining the abnormally low translation error.