RNA-catalysed RNA replication is widely considered a key step in the emergence of life's first genetic system. However, RNA replication can be impeded by the extraordinary stability of duplex RNA products, which must be dissociated for re-initiation of the next replication cycle. Here we have explored rolling circle synthesis (RCS) as a potential solution to this strand separation problem. We observe sustained RCS by a triplet polymerase ribozyme beyond full-length circle synthesis with strand displacement yielding concatemeric RNA products. Furthermore, we show RCS of a circular Hammerhead ribozyme capable of self-cleavage and re-circularisation. Thus, all steps of a viroid-like RNA replication pathway can be catalysed by RNA alone. Finally, we explore potential RCS mechanisms by molecular dynamics simulations, which indicate a progressive build-up of conformational strain upon RCS' with destabilisation of nascent strand 5'- and 3'-ends. Our results have implications for the emergence of RNA replication and for understanding the potential of RNA to support complex genetic processes.
All data generated or analyzed in this manuscript is supplied within the manuscript or supporting file; Source Data files containing original unedited gels images as well as numeric data have been provided for Figures 1,2,4 and 5, as well as figure supplements when relevant.Modelling data and sequencing data are provided as described in the data availability section in the manuscript.
Deep Sequencing data for document titled: Rolling Circle RNA Synthesis Catalysed by RNADryad Digital Repository, doi:10.5061/dryad.tht76hf10.
- Emil Laust Kristoffersen
- Philipp Holliger
- Agnes Noy
- Matthew Burman
- Agnes Noy
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Timothy W Nilsen, Case Western Reserve University, United States
© 2022, Kristoffersen et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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