Three-dimensional structure of a DNA hairpin in solution: two-dimensional NMR studies and distance geometry calculations on d(CGCGTTTTCGCG).
The three-dimensional structure of d(CGCGTTTTCGCG) in solution has been determined from proton NMR data by using distance geometry methods. The rate of dipolar cross-relaxation between protons close together in space is used to calculate distances between proton pairs within 5 A of each other; these distances are used as input to a distance geometry algorithm that embeds this distance matrix in three-dimensional space. The resulting refined structures that best agree with the input distances are all very similar to each other and show that the DNA sequence forms a hairpin in solution; the bases of the loop region are stacked, and the stem region forms a right-handed helix. The advantages and limitations of the technique, as well as the computer requirements of the algorithm, are discussed.
D004247:DNA; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides
D009838:Oligodeoxyribonucleotides; D004247:DNA