Chemically accurate coarse graining of double-stranded DNA.
Coarse-grained (CG) modeling approaches are widely used to simulate many important biological processes involving DNA, including chromatin folding and genomic packaging. The bending propensity of a semiflexible DNA molecule critically influences these processes. However, existing CG DNA models do not retain a sufficient fidelity of the important local chain motions, whose propagation at larger length scales would generate correct DNA persistent lengths, in particular when the solution's ionic strength is widely varied. Here we report on a development of an accurate CG model for the double-stranded DNA chain, with explicit treatment of mobile ions, derived systematically from all-atom molecular dynamics simulations. Our model generates complex local motions of the DNA chain, similar to fully atomistic dynamics, leading also to a quantitative agreement of our simulation results with the experimental data on the dependence of the DNA persistence length on the solution ionic strength. We also predict a structural transition in a torsionally stressed DNA nanocircle as the buffer ionic strength is increased beyond a threshold value.
Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA.
Alexey
A
Savelyev
Garegin A
GA
Papoian
D004247:DNA / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D009690:Nucleic Acid Conformation; D012965:Sodium Chloride / Q000737:chemistry; D055672:Static Electricity
D007477:Ions; D012965:Sodium Chloride; D004247:DNA