https://www.science.org/doi/10.1126/science.adt2760
Abstract
The emergence of a chemical system capable of self-replication and evolution is a critical event in the origin of life. RNA polymerase ribozymes can replicate RNA, but their large size and structural complexity impede self-replication and preclude their spontaneous emergence. Here we describe QT45: a 45-nucleotide polymerase ribozyme, discovered from random sequence pools, that catalyzes general RNA-templated RNA synthesis using trinucleotide triphosphate (triplet) substrates in mildly alkaline eutectic ice. QT45 can synthesize both its complementary strand using a random triplet pool at 94.1% per-nucleotide fidelity, and a copy of itself using defined substrates, both with yields of ~0.2% in 72 days. The discovery of polymerase activity in a small RNA motif suggests that polymerase ribozymes are more abundant in RNA sequence space than previously thought.
Paper is paywalled so can only go by the abstract. Its surprisingly small, high enough fidelity to copy itself faithfully, but also very slow and low yield (which I suppose shouldn’t be surprising given it’s length).
Will be interesting to see what comes of this going forward.
