@article {17,
	title = {DNA-DNA interactions in tight supercoils are described by a small effective charge density},
	journal = {Phys Rev Lett},
	volume = {105},
	year = {2010},
	month = {2010 Oct 8},
	pages = {158101},
	abstract = {<p>DNA-DNA interactions are important for genome compaction and transcription regulation. In studies of such complex processes, DNA is often modeled as a homogeneously charged cylinder and its electrostatic interactions are calculated within the framework of the Poisson-Boltzmann equation. Commonly, a charge adaptation factor is used to address limitations of this theoretical approach. Despite considerable theoretical and experimental efforts, a rigorous quantitative assessment of this parameter is lacking. Here, we comprehensively characterized DNA-DNA interactions in the presence of monovalent ions by analyzing the supercoiling behavior of single DNA molecules held under constant tension. Both a theoretical model and coarse-grained simulations of this process revealed a surprisingly small effective DNA charge of 40\% of the nominal charge density, which was additionally supported by all-atom molecular dynamics simulations.</p>
},
	keywords = {Biomechanical Phenomena, DNA, Superhelical, Molecular Dynamics Simulation, Monte Carlo Method, Salts, Static Electricity},
	issn = {1079-7114},
	doi = {10.1103/PhysRevLett.105.158101 },
	url = {http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.105.158101},
	author = {Christopher Maffeo and Sch{\"o}pflin, Robert and Brutzer, Hergen and Stehr, Ren{\'e} and Aleksei Aksimentiev and Wedemann, Gero and Seidel, Ralf}
}
