Crystal structure of a DNA sequence d(CGTGAATTCACG) at 130K

The crystal structure of the oligonucleotide d(CGTGAATTCACG)has previously been reported as a B-type double helix at a resolution of 2.5 angstrom. Here, the structure of this sequence was determined at a higher resolution of 2.00 angstrom in space group P2(1)2(1)2(1). The adjustmentsin crystal packing between the former and latter are described. The present structure allowed more in depth description of the interactions between the oligonucleotides and with the surrounding solvent: the presence of Mg and Cl ions, a greater number of water molecules and non-classical G center dot center dot center dot G hydrogen bonding interactions between adjacent DNA duplexes.