Reentrant melting of RNA with quenched sequence randomness

Area of Science:

• Thermodynamics
• Biophysics
• Computational Biology

Background:

• RNA secondary structures are crucial for biological functions.
• Understanding RNA folding thermodynamics is essential for predicting structure and function.
• Sequence disorder can significantly impact RNA stability and behavior.

Purpose of the Study:

• To investigate the effect of quenched sequence disorder on RNA secondary structure formation thermodynamics.
• To analytically determine the temperature dependence of free energy, specific heat, and helicity.
• To explore potential mechanisms for RNA cold denaturation.

Main Methods:

• Utilized the constrained annealing approach for thermodynamic calculations.
• Analyzed two- and four-letter alphabet models of RNA sequences.
• Performed analytical derivations for thermodynamic properties.

Main Results:

• Identified reentrant melting behavior at low temperatures due to competing base pairing energies.
• Achieved excellent agreement between analytical results and numerical simulations.
• Demonstrated the influence of quenched disorder on thermodynamic profiles.

Conclusions:

• Quenched sequence disorder introduces a novel mechanism for RNA cold denaturation.
• The findings provide a theoretical framework for understanding experimental observations in RNA folding.
• This research contributes to the fundamental understanding of RNA biophysics and sequence-structure relationships.