1d75

</td></tr><tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=A38:8-OXY+DEOXYADENOSINE-5-MONOPHOSPHATE'>A38</scene></td></tr>

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== Publication Abstract from PubMed ==

The structure of the synthetic deoxydodecamer d(CGCGAATT(O8A)GCG)2 (O8A = 8-oxoadenine) has been determined by single-crystal X-ray diffraction techniques. The oligonucleotide crystallizes in the orthorhombic space group P2(1)2(1)2(1) with cell dimensions of a = 25.48 A, b = 41.84 A, and c = 64.91 A. The refinement has converged with an R-factor of 0.151 for 1119 reflections in the resolution range 8.0-2.25 A. Sixty-seven solvent molecules were located during the course of the refinement. The B-DNA helix consists of ten Watson-Crick base pairs and two guanine-8-oxoadenine (G.O8A) base pairs. In order to achieve hydrogen-bonding complementarity between the two bases, an unusual G(anti).O8A-(syn) wobble conformation is adopted. It is proposed that the G.O8A mispairs are held together by a network of four interbase hydrogen bonds which are the result of the formation of two reverse three-center hydrogen-bonding systems. These involve one carbonyl oxygen lone pair interacting with two hydrogen atoms. In a departure from previous observations of the characteristics of purine-purine anti-syn base pairs, lambda 1 and lambda 2, the angles between the glycosidic bonds and the C1'-C1' vector, are symmetric. A reassessment of the other purine-purine mispairs suggests that similar three-center hydrogen bonds may occur and make a contribution to stabilizing other base pairings.

Conformation of guanine-8-oxoadenine base pairs in the crystal structure of d(CGCGAATT(O8A)GCG).,Leonard GA, Guy A, Brown T, Teoule R, Hunter WN Biochemistry. 1992 Sep 15;31(36):8415-20. PMID:1390625<ref>PMID:1390625</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 1d75" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Brown, T]]

[[Category: Guy, A]]

[[Category: Hunter, W N]]

[[Category: Leonard, G A]]

[[Category: Teoule, R]]

[[Category: Modified]]