In the present paper we address a model of DNA-protein selective interaction. The biochemical model is chosen on the basis of existing literature, both theoretical and experimental. This consists of a restriction enzyme, EcoRI, binding selectively to a 6 base-pair subsequence of an oligonucleotide to cleave it. A signature of the specific partnership of the two molecules is first obtained by applying the so-called Resonant Recognition Model. Then the same system is investigated by means of a model inspired to the standard Davydov and Holstein-Fröhlich models describing the electron motion along a biomolecule. Starting with a model Hamiltonian written in second quantization, the Time Dependent Variational Principle is used to work out the dynamical equations of the system. The time-Fourier spectra of the electron currents numerically computed for the DNA fragment and for the EcoRI enzyme, respectively, are multiplied to get a crossspectrum which displays a sharp peak of co-resonance. The remarkable result is the replacement of this sharp peak with a broad and noisy frequency pattern when the recognition sequence GAATTC on the DNA is randomized. This sequence-dependent charge transfer phenomenology is suggestive of a potentially rich variety of selective electrodynamic interactions of DNA molecules and transcription factors under the action of electron excitation.