title: Adaptation of the base-paired double-helix molecular architecture to extreme pressure.
abstract: The behaviour of the d(GGTATACC) oligonucleotide has been investigated by X-ray crystallography at 295 K in the range from ambient pressure to 2 GPa (approximately 20,000 atm). Four 3D-structures of the A-DNA form (at ambient pressure, 0.55, 1.09 and 1.39 GPa) were refined at 1.60 or 1.65 A resolution. In addition to the diffraction pattern of the A-form, the broad meridional streaks previously explained by occluded B-DNA octamers within the channels of the crystalline A-form matrix were observed up to at least 2 GPa. This work highlights an important property of nucleic acids, their capability to withstand very high pressures, while keeping in such conditions a nearly invariant geometry of base pairs that store and carry genetic information. The double-helix base-paired architecture behaves as a molecular spring, which makes it especially adapted to very harsh conditions. These features may have contributed to the emergence of a RNA World at prebiotic stage.
authors.affiliation: Synchrotron-SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France. eric.girard@synchrotron-soleil.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Girard
authors.forename: Thierry
authors.initials: T
authors.lastname: Prangé
authors.forename: Anne-Claire
authors.initials: AC
authors.lastname: Dhaussy
authors.forename: Evelyne
authors.initials: E
authors.lastname: Migianu-Griffoni
authors.forename: Marc
authors.initials: M
authors.lastname: Lecouvey
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Chervin
authors.forename: Mohamed
authors.initials: M
authors.lastname: Mezouar
authors.forename: Richard
authors.initials: R
authors.lastname: Kahn
authors.forename: Roger
authors.initials: R
authors.lastname: Fourme
mesh_terms: D020029:Base Pairing; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D044704:DNA, A-Form / Q000737:chemistry*; D006874:Hydrostatic Pressure; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*
chemical_list: D044704:DNA, A-Form; D009838:Oligodeoxyribonucleotides; C057781:d(GGTATACC); D004247:DNA