  DNA toroidal bundles form upon condensation of one or multiple DNA filaments.
DNA filaments in toroidal bundles are hexagonally packed, and collectively
twist around the center line of the toroid. In a previous study, we and our
coworkers argue that the filaments' curvature locally correlates with their
density in the bundle, with the filaments less closely packed where their
curvature appears to be higher. We base our claim on the assumption that twist
has a negligible effect on the local curvature of filaments in DNA toroids.
However, this remains to be proven. We fill this gap here, by calculating the
distribution of filaments' curvature in a geometric model of twisted toroidal
bundle, which we use to describe DNA toroids by an appropriate choice of
parameters. This allows us to substantiate our previous study and suggest
directions for future experiments.
