Crystallization and preliminary analysis of the deoxyoligonucleotide d(CGTAGATCTACG)

Two crystal forms of the self-complementary DNA 12-mer d(CGTAGATCTACG) were grown by the vapour diffusion technique. Form I is in space group C2 with a = 64.8 A, b = 35.4 A, c = 24.4 A and beta = 92.2 (1 A = 0.1 nm). The crystals are grown as monoclinic blocks or hexagonal plates. There are two strands (one duplex) in the asymmetric unit. Form II crystallizes as monoclinic blocks, space group P21 with a = 64.5 A, b = 35.1 A, c = 25.2 A and beta = 91.8 degrees. This form contains four strands (2 duplexes) in the asymmetric unit. Both forms are suitable for high resolution X-ray analysis. The diffraction patterns suggest that the DNA is in a B-type conformation and that the packing in the two forms is very similar.