The conformation of a B-DNA decamer is mainly determined by its sequence and not by crystal environment.
By comparing the conformations adopted by a double-stranded decameric B-DNA fragment in different crystal environments, we address the question of the degree of deformability of DNA helices. The three-dimensional structure of the self-complementary DNA decamer CCAGGCmeCTGG has been determined from crystals of space group P6 at 2.25 A resolution with an R value of 17.2% for 2407 1 sigma structure amplitudes. The oligonucleotide forms a B-type double helix with a characteristic sequence-dependent conformation closely resembling that of the corresponding unmethylated decamer, the structure of which is known from a high-resolution analysis of crystals of space group C2. Evidently, both the effects of single-site methylation and altered crystal environment on the DNA conformation are small. Therefore, double-helical DNA may possess sequence-determined conformational features that are less deformable than previously thought.
Heinemann
U
U
Abteilung Saenger, Institut für Kristallographie, Freie Universität Berlin, FRG.
Alings
C
C
D001483:Base Sequence; D004247:DNA / Q000737:chemistry*; D006860:Hydrogen Bonding; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000737:chemistry*; D013816:Thermodynamics; D014961:X-Ray Diffraction / Q000379:methods
D009838:Oligodeoxyribonucleotides; D004247:DNA