Researchers have expanded on efforts to create a semi-synthetic organism (SSO) using analogs to DNA and RNA. Previously, the team of scientists produced a SSO that had an ‘unnatural’ base pair in its DNA, which it was able to transcribe into messenger RNAs and transfer RNAs that allowed for the production of proteins that contained ‘noncanonical’ amino acids (or amino acids outside of the list of those you typically find in proteins made by life).

In the new study, the team explored different analogues to the base pairs usually found in DNA and RNA (deoxy- and ribo- nucleotides). They found that a variety of nucleotides, which have no structural or functional similarity to natural nucleotides, can be incorporated into the cells. In addition, they have identified what they believe to be the optimal unnatural base pairs for creating the target SSO. The newly optimized SSO is capable of producing proteins that contain multiple noncanonical amino acids.

The study, “Optimization of Replication, Transcription, and Translation in a Semi-Synthetic Organism,” was published in the Journal of the American Chemical Society (JACS). The work was supported by NASA Astrobiology through the Exobiology Program.