Genomics, Proteomics, Bioinformatics

Triplet-Encoded Prebiotic RNA Aminoacylation

By Keith Cowing

Status Report

J. Am. Chem. Soc.

November 22, 2023

Filed under amino acids, aminoacyl-tRNA synthetases, chemoselectivity, genomics, J. Am. Chem. Soc., origin of life, prebiotic, proteins, stereoselectivity, tRNA

Triplet-Encoded Prebiotic RNA Aminoacylation — the question arises─before these enzymes evolved, how were primordial tRNAs selectively aminoacylated?

The encoding step of translation involves attachment of amino acids to cognate tRNAs by aminoacyl-tRNA synthetases, themselves the product of coded peptide synthesis. So, the question arises─before these enzymes evolved, how were primordial tRNAs selectively aminoacylated?

Here, we demonstrate enzyme-free, sequence-dependent, chemoselective aminoacylation of RNA. We investigated two potentially prebiotic routes to aminoacyl-tRNA acceptor stem-overhang mimics and analyzed those oligonucleotides undergoing the most efficient aminoacylation. Overhang sequences do not significantly influence the chemoselectivity of aminoacylation by either route.

For aminoacyl-transfer from a mixed anhydride donor strand, the chemoselectivity and stereoselectivity of aminoacylation depend on the terminal three base pairs of the stem. The results support early suggestions of a second genetic code in the acceptor stem.

https://pubs.acs.org/doi/10.1021/jacs.3c03931

J. Am. Chem. Soc. 2023, 145, 29, 15971–15980
Triplet-Encoded Prebiotic RNA Aminoacylation (open access)

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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