Langlois d'Estaintot B, Dautant A, Courseille C, Precigoux G
Laboratoire de Cristallographie et de Physique Cristalline, Unité de Recherche Associée 144, Centre National de la Recherche Scientifique, Université de Bordeaux I, France.
Eur J Biochem. 1993 Apr 15;213(2):673-82. doi: 10.1111/j.1432-1033.1993.tb17807.x.
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.
