Sommaire:

We investigate the influence of non-local couplings on the torsional and bending elasticities of DNA. Such couplings have been observed in the past by several simulation studies. Here, we use a description of DNA conformations based on the variables tilt, roll and twist. Our analysis of both coarse-grained (oxDNA) and all-atom models indicates that these share strikingly similar features: there are strong off-site couplings for tilt-tilt and twist-twist, while they are much weaker in the roll-roll case. By developing an analytical framework to estimate bending and torsional persistence lengths in non-local DNA models, we show how off-site interactions generate a length scale dependent elasticity. Based on the simulation generated elasticity data the theory predicts a significant length scale dependent effect on torsional fluctuations, but only a modest effect on bending fluctuations. These results are in agreement with experiments probing DNA mechanics from single base pair to kilobase pair scales.

Pour plus d'informations, merci de contacter Parmeggiani A.