  Recent experimental data indicate that the elastic wormlike rod model of DNA
that works well on long length scales may break down on shorter scales relevant
to biology. According to Noy and Golestanian (Phys. Rev. Lett. 109, 228101,
2012) molecular dynamics (MD) simulations predict DNA rigidity close to
experimental data and confirm one scenario of such breakdown, namely, that for
lengths of a few helical turns, DNA dynamics exhibit long-range bending and
stretching correlations. Earlier studies using similar forcefields concluded
that (i) MD systematically overestimate the DNA rigidity, and (ii) no
deviations from the WLR model are detectable. Here it is argued that the data
analysis in the above mentioned paper was incorrect and that the earlier
conclusions are valid.
