389d

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=TAF:2-DEOXY-2-FLUORO-ARABINO-FURANOSYL+THYMINE-5-PHOSPHATE'>TAF</scene></td></tr>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The fundamental conformational states of right-handed double helical DNA, the A- and B-forms, are associated with distinct puckers of the sugar moieties. The furanose conformation itself is affected by the steric and electronic nature of the ring substituents. For example, a strongly electronegative substituent at the C2' position, such as in the 2'-deoxy-2'-fluoro ribo furanosyl analogue, will drive the conformational equilibrium towards the C3'- endo type (north). Conversely, the 2'-deoxy-2'-fluoro arabino furanosyl modification with opposite stereochemistry at C2' appears to have a preference for a C2'- endo type pucker (south). Incorporation of 2'-fluoroarabinofuranosyl thymines was previously shown to enhance the thermodynamic stability of B-DNA duplexes. We have determined the crystal structures of the B-DNA dodecamer duplexes [d(CGCGAASSCGCG)]2and [d(CGCGAASTCGCG)]2with incorporated 2'-deoxy-2'-fluoroarabinofuranosyl thymines S (south) at 1.55 A resolution. In the crystal structures, all S residues adopt an O4'- endo conformation (east), well compatible with an overall B-form duplex geometry. In addition to the increased rigidity of S nucleosides, a clathrate-like ordered water structure around the 2'-fluorines may account for the observed larger thermodynamic stability of DNA duplexes containing 2'-deoxy-2'-fluoroarabino thymidines.

Crystal structures of B-DNA with incorporated 2'-deoxy-2'-fluoro-arabino-furanosyl thymines: implications of conformational preorganization for duplex stability.,Berger I, Tereshko V, Ikeda H, Marquez VE, Egli M Nucleic Acids Res. 1998 May 15;26(10):2473-80. PMID:9580702<ref>PMID:9580702</ref>

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

</div>

<div class="pdbe-citations 389d" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Berger, I]]

[[Category: Egli, M]]

[[Category: Ikeda, H]]

[[Category: Marquez, V E]]

[[Category: Tereshko, V]]

[[Category: Modified]]