A Synthetic Molecular System Capable of Mirror-image Genetic Replication and Transcription

Researchers at Tsinghua University in Beijing have created a mirror-image version of a protein that performs two of the most fundamental processes of life : copying DNA and transcribing it into RNA. Researchers have been making chunks of mirror-DNA for decades, but these endeavors never came to an end because, among other things, the complexity and the size of the targeted proteins, as commonly used polymerases have more than 600 amino-acids. So the researches turned to the smallest known polymerase, African swine fever virus polymerase X, which contains just 174 amino acids.

The team constructed a mirror version of the enzyme and found that, like its natural equivalent, it could extend a mirror-primer consisting of 12 nucleotides (DNA building blocks) to an 18-nucleotide mirror-DNA strand in about four hours ; and to a 56-nucleotide strand in 36 hours. When the normal and mirror-image versions of these systems were mixed together in the same test tube, both replication processes worked independently without interference. The mirror-image polymerase could also transcribe mirror-DNA into mirror-RNA, again at a glacial pace. This master piece in synthetic biology, is by all means a terrific milestone, reinforcing a field were a growing number of researchers are .working on looking-glass versions of bio-molecules and their accompanying bio-chemical processes