We report a first-principle study of the electronic and conduction properties of a quadruple-helix guanine wire (G4 wire), a DNA derivative, with inner potassium ions. The analysis of the electronic structure highlights the presence of energy manifolds that are equivalent to the bands of (semi)conducting materials and reveals the formation of extended electron channels available for charge transport along the wire. The specific metal-nucleobase interactions affect the electronic properties at the Fermi level, leading the wire to behave as an intrinsically p-doped system.