Phase Transition between 'A' and 'B' forms of DNA: A Free Energy Perspective

TL;DR

This paper investigates the structural transition between 'A' and 'B' forms of DNA using group theory and free energy concepts, proposing a higher symmetry framework and analyzing the nature of observed conformations.

Contribution

It introduces a group theoretic approach to model the DNA phase transition and develops a Landau-like theory with higher symmetry and order parameters.

Findings

The transition is not of the order-disorder type.

A higher symmetry and relevant order parameters are defined.

Discussion on whether observed conformations are fundamentally different.

Abstract

We study the structural transition from `B' form of DNA to 'A' form of DNA using group theoretic methods. The transition is not of the order-disorder type and hence to construct a Landau kind of theory for the transition we define a higher symmetry and relevant order parameters. We also discuss the issue of all the conformations, observed experimentally during the course of transition, being fundamentally different or not.