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| {{STRUCTURE_388d| PDB=388d | SCENE= }} | | {{STRUCTURE_388d| PDB=388d | SCENE= }} |
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| '''CRYSTAL STRUCTURE OF B-DNA WITH INCORPORATED 2'-DEOXY-2'-FLUORO-ARABINO-FURANOSYL THYMINES: IMPLICATIONS OF CONFORMATIONAL PREORGANIZATION FOR DUPLEX STABILITY'''
| | ===CRYSTAL STRUCTURE OF B-DNA WITH INCORPORATED 2'-DEOXY-2'-FLUORO-ARABINO-FURANOSYL THYMINES: IMPLICATIONS OF CONFORMATIONAL PREORGANIZATION FOR DUPLEX STABILITY=== |
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| ==Overview==
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| 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.
| | The line below this paragraph, {{ABSTRACT_PUBMED_9580702}}, adds the Publication Abstract to the page |
| | (as it appears on PubMed at http://www.pubmed.gov), where 9580702 is the PubMed ID number. |
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| | {{ABSTRACT_PUBMED_9580702}} |
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| ==About this Structure== | | ==About this Structure== |
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| [[Category: Double helix]] | | [[Category: Double helix]] |
| [[Category: Modified]] | | [[Category: Modified]] |
| ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 20:18:28 2008'' | | |
| | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jul 28 20:22:44 2008'' |
