Coarse Graining DNA: Symmetry, Nonlocal Elasticity, and Persistence Length

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.

Automated summary

By utilizing the rigid base-pair model, this study establishes a connection between the microscopic parameters of DNA and its persistence length, shedding light on the determination of the scale dependence of elastic moduli. This has implications for understanding DNA-protein interactions and nucleosome diffusion mechanism.