Stability of free and mineral-protected nucleic acids: Implications for the RNA world.
Geochimica et Cosmochimica Acta
360 - 378.
Using molecular dynamics simulations we study the structural stability of three different nucleic acids intercalated within a magnesium aluminium layered double hydroxide (LDH) mineral, at varying degrees of hydration, and free in aqueous solution. The nucleotides investigated are ribose nucleic acid (RNA), deoxyribose nucleic acid (DNA) and peptide nucleic acid (PNA), all in duplex form. Our simulations show that DNA has enhanced Watson–Crick hydrogen-bonding when intercalated within the LDH clay interlayers, compared with intercalated RNA and PNA, whilst the reverse trend is found for the nucleic acids in bulk water. The tendency for LDH to alter the stability of the three nucleic acids persists for higher temperature and pressure conditions. The uncharged protein backbone of PNA is found to have a detrimental effect on the overall stability of the duplex, as it experiences a greatly reduced electrostatic interaction with the charged LDH sheets compared to RNA and DNA. Assuming an RNA world, in which RNA preceded the DNA/protein world, at some point in time DNA must have taken over the role as the information storage molecule from RNA. These results suggest that a mineral based origin of life may have favoured DNA as the information-storage biomolecule over potentially competing RNA and PNA, providing a route to modern biology from the RNA world.
|Title:||Stability of free and mineral-protected nucleic acids: Implications for the RNA world|
|Open access status:||An open access version is available from UCL Discovery|
|Additional information:||This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.|
|UCL classification:||UCL > School of BEAMS > Faculty of Maths and Physical Sciences > Chemistry|
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