title: Arginine-phosphate salt bridges between histones and DNA: intermolecular actuators that control nucleosome architecture.
abstract: Structural bioinformatics and van der Waals density functional theory are combined to investigate the mechanochemical impact of a major class of histone-DNA interactions, namely, the formation of salt bridges between arginine residues in histones and phosphate groups on the DNA backbone. Principal component analysis reveals that the configurational fluctuations of the sugar-phosphate backbone display sequence-specific directionality and variability, and clustering of nucleosome crystal structures identifies two major salt-bridge configurations: a monodentate form in which the arginine end-group guanidinium only forms one hydrogen bond with the phosphate, and a bidentate form in which it forms two. Density functional theory calculations highlight that the combination of sequence, denticity, and salt-bridge positioning enables the histones to apply a tunable mechanochemical stress to the DNA via precise and specific activation of backbone deformations. The results suggest that selection for specific placements of van der Waals contacts, with high-precision control of the spatial distribution of intermolecular forces, may serve as an underlying evolutionary design principle for the structure and function of nucleosomes, a conjecture that is corroborated by previous experimental studies.
authors.affiliation: Department of Physics and Astronomy, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA.
authors.forename: Tahir I
authors.initials: TI
authors.lastname: Yusufaly
authors.affiliation: Department of Chemistry and Biochemistry, Delaware Valley College, Doylestown, Pennsylvania 18901, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Chemistry and Chemical Biology and BioMaPS Institute for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA.
authors.forename: Gautam
authors.initials: G
authors.lastname: Singh
authors.affiliation: Department of Chemistry and Chemical Biology and BioMaPS Institute for Quantitative Biology, Rutgers, the State University of New Jersey, Piscataway, New Jersey 08854, USA.
authors.forename: Wilma K
authors.initials: WK
authors.lastname: Olson
mesh_terms: D001120:Arginine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D006657:Histones / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009707:Nucleosomes / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011487:Protein Conformation; D011789:Quantum Theory
chemical_list: D006657:Histones; D009707:Nucleosomes; D010710:Phosphates; D004247:DNA; D001120:Arginine