Unzipping of DNA with correlated base-sequence

TL;DR

This paper investigates how correlated base-sequences in DNA affect the force-induced unzipping transition, revealing that correlations can enhance stability and lead to diverse unzipping behaviors, which may explain biological functions.

Contribution

It analyzes the impact of finite-range and long-range correlations in DNA sequences on unzipping transitions, highlighting novel effects of correlations on stability and transition dynamics.

Findings

Finite-range correlations increase DNA stability against unzipping force.

Long-range correlations can eliminate or alter the unzipping phase transition.

Unzipping behavior varies significantly depending on sequence correlations.

Abstract

We consider force-induced unzipping transition for a heterogeneous DNA model with a correlated base-sequence. Both finite-range and long-range correlated situations are considered. It is shown that finite-range correlations increase stability of DNA with respect to the external unzipping force. Due to long-range correlations the number of unzipped base-pairs displays two widely different scenarios depending on the details of the base-sequence: either there is no unzipping phase-transition at all, or the transition is realized via a sequence of jumps with magnitude comparable to the size of the system. Both scenarios are different from the behavior of the average number of unzipped base-pairs (non-self-averaging). The results can be relevant for explaining the biological purpose of correlated structures in DNA.