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bioRxiv · 10.1101/770578

Non-enzymatic primer extension with strand displacement

Zhou, L.·Kim, S. C.·Ho, K. H.·O'Flaherty, D. K.·Giurgiu, C.·Wright, T. H.·Szostak, J. W.
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Abstract

Non-enzymatic RNA self-replication is integral to the RNA World hypothesis. Despite considerable progress in non-enzymatic template copying, true replication remains challenging due to the difficulty of separating the strands of the product duplex. Here, we report a prebiotically plausible solution to this problem in which short invader oligonucleotides unwind an RNA duplex through a toehold/branch migration mechanism, allowing non-enzymatic primer extension on a template that was previously occupied by its complementary strand. Kinetic studies of single-step reactions suggest that following invader binding, branch migration results in a 2:3 partition of the template between open and closed states. Finally, we demonstrate continued primer extension with strand displacement by employing activated 3'-aminonucleotides, a more reactive proxy for ribonucleotides. Our study suggests that complete cycles of non-enzymatic replication of the primordial genetic material may have been catalyzed by short RNA oligonucleotides.

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Zhou, L., Kim, S. C., Ho, K. H., O'Flaherty, D. K., Giurgiu, C., Wright, T. H., Szostak, J. W.. 2019-09-16. Non-enzymatic primer extension with strand displacement. https://doi.org/10.1101/770578

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