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| - | [[Image:287d.gif|left|200px]] | |
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| - | <!--
| + | ==X-RAY AND SOLUTION STUDIES OF DNA OLIGOMERS AND IMPLICATIONS FOR THE STRUCTURAL BASIS OF A-TRACT-DEPENDENT CURVATURE== |
| - | The line below this paragraph, containing "STRUCTURE_287d", creates the "Structure Box" on the page.
| + | <StructureSection load='287d' size='340' side='right'caption='[[287d]], [[Resolution|resolution]] 2.20Å' scene=''> |
| - | You may change the PDB parameter (which sets the PDB file loaded into the applet)
| + | == Structural highlights == |
| - | or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
| + | <table><tr><td colspan='2'>[[287d]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=287D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=287D FirstGlance]. <br> |
| - | or leave the SCENE parameter empty for the default display.
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.2Å</td></tr> |
| - | -->
| + | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=287d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=287d OCA], [https://pdbe.org/287d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=287d RCSB], [https://www.ebi.ac.uk/pdbsum/287d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=287d ProSAT]</span></td></tr> |
| - | {{STRUCTURE_287d| PDB=287d | SCENE= }}
| + | </table> |
| - | | + | __TOC__ |
| - | '''X-RAY AND SOLUTION STUDIES OF DNA OLIGOMERS AND IMPLICATIONS FOR THE STRUCTURAL BASIS OF A-TRACT-DEPENDENT CURVATURE'''
| + | </StructureSection> |
| - | | + | [[Category: Large Structures]] |
| - | | + | [[Category: Eisenstein M]] |
| - | ==Overview== | + | [[Category: Shakked Z]] |
| - | DNA containing short periodic stretches of adenine residues (known as A-tracts), which are aligned with the helical repeat, exhibit a pronounced macroscopic curvature. This property is thought to arise from the cumulative effects of a distinctive structure of the A-tract. It has also been observed by gel electrophoresis that macroscopic curvature is largely retained when inosine bases are introduced singly into A-tracts but decreases abruptly for pure I-tracts. The structural basis of this effect is unknown. Here we describe X-ray and gel electrophoretic analyses of several oligomers incorporating adenine or inosine bases or both. We find that macroscopic curvature is correlated with a distinctive base-stacking geometry characterized by propeller twisting of the base-pairs. Regions of alternating adenine and inosine bases display large propeller twisting comparable to that of pure A-tracts, whereas the values observed for pure I-tracts are significantly smaller. We also observe in the crystal structures that propeller twist leads to close cross-strand contacts between amino groups from adenine and cytosine bases, indicating an attractive NH-N interaction, which is analogous to the NH-O interaction proposed for A-tracts. This interaction also occurs between adenine bases across an A-T step and may explain in part the different behavior of A-T versus T-A steps in the context of A-tract-induced curvature. We also note that hydration patterns may contribute to propeller-twisted conformation. Based on the present data and other structural and biophysical studies, we propose that DNA macroscopic curvature is related to the structural invariance of A-tract and A-tract-like regions conferred by high propeller twist, cross-strand interactions and characteristic hydration. The implications of these findings to the mechanism of DNA bending are discussed.
| + | [[Category: Shatzky-Schwartz M]] |
| - | | + | |
| - | ==About this Structure== | + | |
| - | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=287D OCA]. | + | |
| - | | + | |
| - | ==Reference== | + | |
| - | X-ray and solution studies of DNA oligomers and implications for the structural basis of A-tract-dependent curvature., Shatzky-Schwartz M, Arbuckle ND, Eisenstein M, Rabinovich D, Bareket-Samish A, Haran TE, Luisi BF, Shakked Z, J Mol Biol. 1997 Apr 4;267(3):595-623. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/9126841 9126841] | + | |
| - | [[Category: Eisenstein, M.]] | + | |
| - | [[Category: Shakked, Z.]] | + | |
| - | [[Category: Shatzky-Schwartz, M.]] | + | |
| - | [[Category: B-dna]] | + | |
| - | [[Category: Double helix]] | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sat May 3 18:25:32 2008''
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