Impact of loop statistics on the thermodynamics of RNA folding

TL;DR

This paper investigates how loop statistics, modeled by a power-law weight, influence the thermodynamic properties of RNA folding, revealing a sensitive dependence of heat capacity and critical behavior on loop exponents.

Contribution

It introduces a model incorporating loop length statistics into RNA folding thermodynamics and analytically derives how critical temperature and exponents depend on the loop exponent c.

Findings

Heat capacity depends on the loop exponent c.

Critical temperature and exponents vary with c.

Non-universal behavior observed in RNA thermodynamics.

Abstract

Loops are abundant in native RNA structures and proliferate close to the unfolding transition. By including a statistical weight ~ l^{-c} for loops of length l in the recursion relation for the partition function, we show that the calculated heat capacity depends sensitively on the presence and value of the exponent c, even of short t-RNA. For homo-RNA we analytically calculate the critical temperature and critical exponents which exhibit a non-universal dependence on c.