9dna

<StructureSection load='9dna' size='340' side='right' caption='[[9dna]], [[Resolution|resolution]] 1.80&Aring;' scene=''>

<table><tr><td colspan='2'>[[9dna]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9DNA OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=9DNA FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=9dna FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9dna OCA], [http://pdbe.org/9dna PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=9dna RCSB], [http://www.ebi.ac.uk/pdbsum/9dna PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=9dna ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

Single crystals of the self-complementary octadeoxyribonucleotide d(GCCCGGGC) have been analysed by X-ray diffraction methods at a resolution of 1.8 A. The tetragonal unit cell of space group P4(3)2(1)2 has dimensions of a = 43.25 A and c = 24.61 A and contains eight strands of the oligonucleotide. The structure was refined by standard crystallographic techniques to an R factor of 17.1% using 1359 3 sigma structure factor observations. Two strands of the oligonucleotide are related by the crystallographic dyad axis to form a DNA helix in the A conformation. The d(GCCCGGGC) helix is characterized by a wide open major groove, a near perpendicular orientation of base pairs to the helix axis and an unusually small average helix twist angle of 31.3 degrees indicating a slightly underwound helix with 11.5 base pairs per turn. Extensive cross-strand stacking between guanine bases at the central cytosine-guanine step is made possible by a number of local conformational adjustments including a fully extended sugar-phosphate backbone of the central guanosine nucleotide.

Crystal structure analysis of an A-DNA fragment at 1.8 A resolution: d(GCCCGGGC).,Heinemann U, Lauble H, Frank R, Blocker H Nucleic Acids Res. 1987 Nov 25;15(22):9531-50. PMID:3684603<ref>PMID:3684603</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 9dna" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Heinemann, U]]

[[Category: A-dna]]

[[Category: Double helix]]