title: The intrinsic mechanics of B-DNA in solution characterized by NMR.
abstract: Experimental characterization of the structural couplings in free B-DNA in solution has been elusive, because of subtle effects that are challenging to tackle. Here, the exploitation of the NMR measurements collected on four dodecamers containing a substantial set of dinucleotide sequences provides new, consistent correlations revealing the DNA intrinsic mechanics. The difference between two successive residual dipolar couplings (ΔRDCs) involving C6/8-H6/8, C3'-H3' and C4'-H4' vectors are correlated to the(31)P chemical shifts (δP), which reflect the populations of the BI and BII backbone states. The δPs are also correlated to the internucleotide distances (Dinter) involving H6/8, H2' and H2″ protons. Calculations of NMR quantities on high resolution X-ray structures and controlled models of DNA enable to interpret these couplings: the studied ΔRDCs depend mostly on roll, while Dinterare mainly sensitive to twist or slide. Overall, these relations demonstrate how δP measurements inform on key inter base parameters, in addition to probe the BI↔BII backbone equilibrium, and shed new light into coordinated motions of phosphate groups and bases in free B-DNA in solution. Inspection of the 5' and 3' ends of the dodecamers also supplies new information on the fraying events, otherwise neglected.
authors.affiliation: Laboratoire de Biologie et Pharmacologie Appliquée, ENS Cachan, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan cedex, France Université Pierre et Marie Curie, 4 Place Jussieu, 75005 Paris, France.
authors.forename: Akli Ben
authors.initials: AB
authors.lastname: Imeddourene
authors.affiliation: Laboratoire de Biologie et Pharmacologie Appliquée, ENS Cachan, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan cedex, France Department of Life Sciences, East China Normal University, 200062 Shanghai, People's Republic of China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Xu
authors.affiliation: Laboratoire de Biologie et Pharmacologie Appliquée, ENS Cachan, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan cedex, France.
authors.forename: Loussiné
authors.initials: L
authors.lastname: Zargarian
authors.affiliation: Laboratoire de Physique Théorique et Modélisation, UMR 8089, CNRS, Université de Cergy-Pontoise, Cergy-Pontoise, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Oguey
authors.affiliation: 51 Natal Road, Cambridge CB1 3NY, UK.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foloppe
authors.affiliation: Laboratoire de Biologie et Pharmacologie Appliquée, ENS Cachan, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan cedex, France olivier.mauffret@lbpa.ens-cachan.fr.
authors.forename: Olivier
authors.initials: O
authors.lastname: Mauffret
authors.affiliation: Laboratoire de Biologie et Pharmacologie Appliquée, ENS Cachan, CNRS, Université Paris-Saclay, 61 avenue du Président Wilson, 94235 Cachan cedex, France bhartman@ens-cachan.fr.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Hartmann
mesh_terms: D059371:DNA, B-Form / Q000737:chemistry*; D003854:Deoxyribonucleotides / Q000737:chemistry; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D009690:Nucleic Acid Conformation
chemical_list: D059371:DNA, B-Form; D003854:Deoxyribonucleotides