  While the behavior of double stranded DNA at mesoscopic scales is fairly well
understood, less is known about its relation to the rich mechanical properties
in the base-pair scale, which is crucial, for instance, to understand
DNA-protein interactions and the nucleosome diffusion mechanism. Here, by
employing the rigid base pair model, we connect its microscopic parameters to
the persistence length. Combined with all-atom molecular dynamic simulations,
our scheme identifies relevant couplings between different degrees of freedom
at each coarse-graining step. This allows us to clarify how the scale
dependence of the elastic moduli is determined in a systematic way encompassing
the role of previously unnoticed off site couplings between deformations with
different parity.
