  We study the transport of charge due to polarons in a model of DNA which
takes in account its 3D structure and the coupling of the electron wave
function with the H--bond distortions and the twist motions of the base pairs.
Perturbations of the ground states lead to moving polarons which travel long
distances. The influence of parametric and structural disorder, due to the
impact of the ambient, is considered, showing that the moving polarons survive
to a certain degree of disorder. Comparison of the linear and tail analysis and
the numerical results makes possible to obtain further information on the
moving polaron properties.
