  We present a novel electromagnetic model of DNA molecules, in which the
P-bonds act as tunnel junctions and the H-bonds as capacitors. Excess charge in
the model gives rise to two coupled modified sine-Gordon equations, which admit
topological solitonic excitations. We study the dynamics of the solitons, their
effect on the DNA transport properties, and comment about their role in the DNA
functioning. We propose specific experiments in order to test our predictions.
