In addition to impacting binding between DNA and the entire polyarginine chain, chain length also impacted the dynamics of interactions between DNA and individual arginine residues. We calculated the contact fraction (i.e., the fraction of simulation snapshots in which the residue was in contact with DNA) for each arginine residue (Figure ). For each type of peptide, ~15 residues form stable interactions with the DNA and remain in contact with the DNA throughout the simulation (contact fraction > 0.99). About 50 additional residues contact the DNA at some point during the simulation (contact fraction between 0.01 and 0.99). For the ~50 arginine residues most commonly in contact with the DNA, there appears to be a relationship between the contact fraction and chain length, as the long R20 tends to have more residues that make a higher contact fraction (fraction greater than 0.5) than the other two systems.