Mirror-Image Gene Transcription and Reverse Transcription

The flow of genetic information between DNA, RNA, and protein lays themolecular foundation of life. Here, we show the transcription of a mirror-image gene into L-RNA and reverse transcription into L-DNA by synthetic D-polymerases based on designed mutants of the DNA polymerase Dpo4. Furthermore, the reverse-transcribed L-DNA was amplified by mirror-image PCR and sequenced by nucleobase-specific chemical cleavage. As a step toward the synthesis of amirror-image ribosome, we enzymatically transcribed full-length mirror-image 5S rRNA. The realization of a comprehensive mirror-image transcription, reverse transcription, PCR, and sequencing toolbox will enable the directed evolution of nuclease-resistant L-RNA aptamers and ribozymes and spur the development of other functional mirror-image molecular systems.