CRC 235 Emergence of Life

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tRNA sequences can assemble into a replicator

A. Kühnlein 2021 eLife


Alexandra Kühnlein, Simon A. Lanzmich, and Dieter Braun



Can replication and translation emerge in a single mechanism via self-assembly? Thekey molecule, transfer RNA (tRNA), is one of the most ancient molecules and contains the geneticcode. Our experiments show how a pool of oligonucleotides, adapted with minor mutations fromtRNA, spontaneously formed molecular assemblies and replicated information autonomously usingonly reversible hybridization under thermal oscillations. The pool of cross-complementary hairpinsself-selected by agglomeration and sedimentation. The metastable DNA hairpins bound to atemplate and then interconnected by hybridization. Thermal oscillations separated replicates fromtheir templates and drove an exponential, cross-catalytic replication. The molecular assembly couldencode and replicate binary sequences with a replication fidelity corresponding to 85–90 % pernucleotide. The replication by a self-assembly of tRNA-like sequences suggests that early forms oftRNA could have been involved in molecular replication. This would link the evolution of translationto a mechanism of molecular replication.

LMU Press Release: Origin of Life: The chicken-and-the-egg problem