Ribozyme-catalysed RNA synthesis using triplet building blocks
- MRC Laboratory of Molecular Biology, United Kingdom
Abstract
RNA-catalyzed RNA replication is widely believed to have supported a primordial biology. However, RNA catalysis is dependent upon RNA folding, and this yields structures that can block replication of such RNAs. To address this apparent paradox we have re-examined the building blocks used for RNA replication. We report RNA-catalysed RNA synthesis on structured templates when using trinucleotide triphosphates (triplets) as substrates, catalysed by a general and accurate triplet polymerase ribozyme that emerged from in vitro evolution as a mutualistic RNA heterodimer. The triplets cooperatively invaded and unraveled even highly stable RNA secondary structures, and support non-canonical primer-free and bidirectional modes of RNA synthesis and replication. Triplet substrates thus resolve a central incongruity of RNA replication, and here allow the ribozyme to synthesise its own catalytic subunit '+' and '-' strands in segments and assemble them into a new active ribozyme.
Data availability
All data generated during this study and collated sequencing results are included in the manuscript and its supporting files. Source data files have been provided for Figures 1-4, 8 and 9.
Article and author information
Author details
Funding
Medical Research Council (MC_U105178804)
- Philipp Holliger
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2018, Attwater 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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Further reading
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Did life on Earth start with RNA?
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