We study the nonlinear dynamics of a deformed Deoxyribonucleic acid (DNA) molecular
chain which is governed by a perturbed sine-Gordon equation coupled with a linear wave
equation representing the lattice deformation. The DNA chain considered here is assumed
to be deformed periodically which is the energetically favourable configuration, and the
periodic deformation is due to the repulsive force between base pairs, stress in the helical
backbones and due to the elastic strain force in both the strands. A multiple scale soliton …