title: Structure of d(CCCCGGTACCGGGG)2 at 1.65 Å resolution.
abstract: The crystal structure of the tetradecanucleotide d(CCCCGGTACCGGGG)2 has previously been reported as an A-type double helix at a resolution of 2.5 Å in space group P41. Here, the structure of this sequence was determined at a significantly higher resolution of 1.65 Å in space group P4₁2₁2. The differences in crystal packing between the former and latter are described. The crystallographic asymmetric unit consists of one tetradecanucleotide duplex that spans more than one full turn of the A-helix. This structure allowed the unambiguous identification of solvent interactions.
authors.affiliation: CAS in Crystallography and Biophysics, University of Madras, Guindy, Chennai, Tamil Nadu 600 025, India.
authors.forename: Monica
authors.initials: M
authors.lastname: Purushothaman
authors.affiliation: CAS in Crystallography and Biophysics, University of Madras, Guindy, Chennai, Tamil Nadu 600 025, India.
authors.forename: Anna
authors.initials: A
authors.lastname: Varghese
authors.affiliation: Institut Européen de Chimie et Biologie (IECB), 2 Rue Robert Escarpit, 33607 Pessac CEDEX, France.
authors.forename: Pradeep Kumar
authors.initials: PK
authors.lastname: Mandal
authors.affiliation: CAS in Crystallography and Biophysics, University of Madras, Guindy, Chennai, Tamil Nadu 600 025, India.
authors.forename: Namasivayam
authors.initials: N
authors.lastname: Gautham
mesh_terms: D020029:Base Pairing; D018360:Crystallography, X-Ray; D044704:DNA, A-Form / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D044704:DNA, A-Form; D009838:Oligodeoxyribonucleotides; D014867:Water
keywords: A-DNA; double helix; right handed; tetradecanucleotide