Wrinkled DNA.
The B form of poly d(GC):poly d(GC) in orthorhombic microcrystallites in oriented fibers has a secondary structure in which a dinucleotide is the repeated motif rather than a mononucleotide as in standard, smooth B DNA. One set of nucleotides (probably GpC) has the same conformations as the smooth form but the alternate (CpG) nucleotides have a different conformation at C3'-O3'. This leads to a distinctive change in the orientation of the phosphate groups. Similar perturbations can be detected in other poly d(PuPy):poly d(PuPy) DNAs such as poly d(IC):poly d(IC) and poly d(AT):poly d(AT) in their D forms which have tetragonal crystal environments. This suggests that such perturbations are intrinsic to all stretches of duplex DNA where purines and pyrimidines alternate and may play a role in the detection and exploitation of such sequences by regulatory proteins.
D004247:DNA; D015226:Dinucleoside Phosphates; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides; D011089:Polydeoxyribonucleotides; D013329:Structure-Activity Relationship; D014961:X-Ray Diffraction
D015226:Dinucleoside Phosphates; D009841:Oligonucleotides; D011089:Polydeoxyribonucleotides; D004247:DNA