Chiral selection in wrapping, crossover, and braiding of DNA mediated by asymmetric bend-writhe elasticity

摘要: Wrapping, crossover, and braiding of DNA are the motifs fundamental interest in genome packaging, gene regulation, enzyme recognition. This study explores elastic mechanisms for selection chirality wrapping, based on a coarse-grained model. The model consists two chains that mutually intertwine right-handed manner forming double-stranded helix with distinction between major minor grooves. Although individual potential energy functions have no asymmetry terms left right twist, as whole exhibits an asymmetric propensity to writhe direction upon bending due helical geometry. Monte Carlo simulations this suggest has prefer left-handed wrapping around spherical core particle also uniform rod coupling writhing. result indicates origin nucleosomes implications rod-like molecules. juxtaposed molecules can braid each other spontaneously under moderate attractive interactions preference suggests importance elasticity pair