Origin & Evolution of Life

Assembly Of Catalytic Complexes From Randomized Oligonucleotides

By Keith Cowing

Status Report

Science Advances via PubMed

May 3, 2025

Filed under catalytic RNA, DNA, oligomer, oligonucleotide, ribozyme, RNA, Science Advances via PubMed

Assembly Of Catalytic Complexes From Randomized Oligonucleotides — A) Sequence alignment tree of the 45 biochemically tested RNAs. Clustering of the RNAs by sequence alignment coincided by the RNA’s use of specific DNA cofactors as coded by different colors. Clusters were determined by both RNA sequence distances and the DNA cofactors they recruited. The name of each of the 14 clusters and its most abundant sequence are given on the right. Sequences given in parentheses name the representative RNAs that were tested biochemically. The detailed tree with all 1331 sequences is shown in fig. S4. (B) Network illustrating the edit distances between the biochemically tested 45 RNAs (circles). The size of the circles represents the relative abundance of the RNA in selection round 6. The color of the circles reflects DNA cofactor use and is the same as the 14 clusters in panel A and Fig. 2. The numbers on the lines are the edit distances between the two connected RNAs. — Science Advances via PubMed

The early evolution of life relied on catalytic RNAs (ribozymes) for central functions.

To test whether early catalysts could have assembled from multiple short nucleic acid fragments in random sequence environments, we performed an in vitro selection from a short RNA library in the presence of 256 different DNA 20-nucleotide oligomers. High-throughput sequencing and biochemical analysis showed that most of the selected 1331 RNA sequences required at least one DNA for activity.

Representatives for four of six RNA clusters that depended on DNA cofactors were active even when the 256 DNAs were replaced by completely random DNA 20-nucleotide oligomers.

The formation of these catalytic complexes and the recruitment of oligonucleotide cofactors from completely random libraries demonstrate an important principle for the emergence of the earliest oligonucleotide catalysts.

Assembly of catalytic complexes from randomized oligonucleotides, Science Advances via PubMed

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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