Mechanism underlying the observed co-resonance of DNA–EcoRI electron currents

Explain the physical mechanism that produces the co-resonance peak observed in the time-domain Fourier cross-spectrum of alternating electron currents along a DNA fragment and the EcoRI enzyme when the DNA contains the specific six-base-pair recognition sequence GAATTC.

Background

Using a second-quantized Davydov/Holstein-Fröhlich-inspired model, the authors compute electron currents along DNA and EcoRI and find a sharp co-resonance peak in their cross-spectrum for the canonical EcoRI target sequence, which disappears upon sequence randomization. This sequence-dependent effect suggests selective electrodynamic interactions.

Despite the robust numerical phenomenology, the authors state that the underlying physics of the co-resonance requires clarification, indicating an unresolved mechanistic account linking model dynamics, biophysical interactions, and potential water-mediated or dispersion-driven effects.