1bna

STRUCTURE OF A B-DNA DODECAMER. CONFORMATION AND DYNAMICS

spinqualitylabelsall models 1bna, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1bna is a 2 chain structure. The November 2001 RCSB PDB Molecule of the Month feature on DNA by David S. Goodsell is 10.2210/rcsb_pdb/mom_2001_11. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Resources: FirstGlance, OCA, RCSB, PDBsum Publication Abstract from PubMed The crystal structure of the synthetic DNA dodecamer d(CpGpCpGpApApTpTpCpGpCpG) has been refined to a residual error of R = 17.8% at 1.9-A resolution (two-sigma data). The molecule forms slightly more than one complete turn of right-handed double-stranded B helix. The two ends of the helix overlap and interlock minor grooves with neighboring molecules up and down a 2(1) screw axis, producing a 19 degrees bend in helix axis over the 11-base-pair steps of the dodecamer. In the center of the molecule, where perturbation is least, the helix has a mean rotation of 36.9 degrees per step, or 9.8 base pairs per turn. The mean propeller twist (total dihedral angle between base planes) between A . T base pairs in the center of the molecule is 17.3 degrees, and that between C . G pairs on the two ends averages 11.5 degrees. Individual deoxyribose ring conformations as measured by the C5'-C4'-C3'-O3' torsion angle delta, exhibit an approximately Gaussian distribution centered around the C1'-exo position with delta avg = 123 degrees and a range of 79 degrees to 157 degrees. Purine sugars cluster at high delta values, and pyrimidine sugars cluster at lower delta. A tendency toward 2-fold symmetry in sugar conformation about the center of the molecule is detectable in spite of the destruction of ideal 2-fold symmetry by the molecular bending. More strikingly, sugar conformations of paired based appear to follow a "principle of anticorrelation," with delta values lying approximately the same distance to either side of the center value, delta = 123 degrees. This same anticorrelation is also observed in other DNA and DNA . RNA structures. Structure of a B-DNA dodecamer: conformation and dynamics.,Drew HR, Wing RM, Takano T, Broka C, Tanaka S, Itakura K, Dickerson RE Proc Natl Acad Sci U S A. 1981 Apr;78(4):2179-83. PMID:6941276 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also DNA Highest impact structures PDB identification code

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