Data and code from: A small polymerase ribozyme that can synthesize itself and its complementary strand

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.