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arXiv · 2403.15352

Universal Cold RNA Phase Transitions

Paolo Rissone·Aurelien Severino·Isabel Pastor·Felix Ritort
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Abstract

RNA's diversity of structures and functions impacts all life forms since primordia. We use calorimetric force spectroscopy to investigate RNA folding landscapes in previously unexplored low-temperature conditions. We find that Watson-Crick RNA hairpins, the most basic secondary structure elements, undergo a glass-like transition below $\mathbf{T_G\sim 20 ^{\circ}}$C where the heat capacity abruptly changes and the RNA folds into a diversity of misfolded structures. We hypothesize that an altered RNA biochemistry, determined by sequence-independent ribose-water interactions, outweighs sequence-dependent base pairing. The ubiquitous ribose-water interactions lead to universal RNA phase transitions below $\mathbf{T_G}$, such as maximum stability at $\mathbf{T_S\sim 5 ^{\circ}}$C where water density is maximum, and cold denaturation at $\mathbf{T_C\sim-50^{\circ}}$C. RNA cold biochemistry may have a profound impact on RNA function and evolution.

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Paolo Rissone, Aurelien Severino, Isabel Pastor, Felix Ritort. 2024-03-22. Universal Cold RNA Phase Transitions. https://arxiv.org/abs/2403.15352

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