Orthorhombic crystal structure of the A-DNA octamer d(GTACGTAC). Comparison with the tetragonal structure.
The X-ray crystal structure of the double-helical A-DNA octanucleotide d(GTACGTAC) has been solved by molecular replacement and refined to a resolution of 0.219 nm. The final R-factor is equal to 16.1% for 1516 observed reflections with F > 4 sigma(F). The sequence crystallizes as an A-DNA-type double helix in the orthorhombic space group P2(1)2(1)2, with one duplex molecule solvated by 66 water molecules in the asymmetric unit. Cell parameters are a = 3.860 nm, b = 5.082 nm, c = 2.174 nm. It is the first time that such a crystal form has been observed. This orthorhombic structure has been compared with the tetragonal structure of the same oligonucleotide. It adopts a bent structure with an unusual packing between symmetry-related molecules.
Langlois d'Estaintot
B
B
Laboratoire de Cristallographie et de Physique Cristalline, Unité de Recherche Associée 144, Centre National de la Recherche Scientifique, Université de Bordeaux I, France.
Dautant
A
A
Courseille
C
C
Precigoux
G
G
D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000737:chemistry*; D014961:X-Ray Diffraction / Q000379:methods
D009838:Oligodeoxyribonucleotides; D004247:DNA