|
|
| (10 intermediate revisions not shown.) |
| Line 1: |
Line 1: |
| - | [[Image:167d.gif|left|200px]] | |
| | | | |
| - | <!--
| + | ==THE CRYSTAL STRUCTURE OF C-C-A-T-T-A-A-T-G-G: IMPLICATIONS FOR BENDING OF B-DNA AT T-A STEPS== |
| - | The line below this paragraph, containing "STRUCTURE_167d", creates the "Structure Box" on the page.
| + | <StructureSection load='167d' size='340' side='right'caption='[[167d]], [[Resolution|resolution]] 2.30Å' 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'>[[167d]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=167D OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=167D 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]] 2.3Å</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=167d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=167d OCA], [https://pdbe.org/167d PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=167d RCSB], [https://www.ebi.ac.uk/pdbsum/167d PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=167d ProSAT]</span></td></tr> |
| - | {{STRUCTURE_167d| PDB=167d | SCENE= }}
| + | </table> |
| - | | + | __TOC__ |
| - | '''THE CRYSTAL STRUCTURE OF C-C-A-T-T-A-A-T-G-G: IMPLICATIONS FOR BENDING OF B-DNA AT T-A STEPS'''
| + | </StructureSection> |
| - | | + | [[Category: Large Structures]] |
| - | | + | [[Category: Dickerson RE]] |
| - | ==Overview== | + | [[Category: Goodsell DS]] |
| - | The single-crystal X-ray analysis of trigonal C-C-A-T-T-A-A-T-G-G, and its comparison with orthorhombic C-G-A-T-T-A-A-T-C-G, have shown that the A-T-T-A-A-T sequence has limited polymorphism under the influence of packing forces from neighboring molecules in the crystal. The T-A step is intrinsically variable. It is not inconsistent with a large propeller twist, a narrow minor groove, and a single spine of hydration, as has sometimes been claimed on theoretical grounds. The T-A step does show a persistent positive roll, in a direction that compresses the major groove, and this may be a significant factor in macroscopic DNA curvature induced by phased A-tracts. A-tracts, as understood in this paper, include A-A and A-T steps, but not the T-A step, which is disruptive. Three conclusions regarding A-tract-induced curvature can be drawn from this and other X-ray crystal structure analyses, and from key gel retardation experiments: (1) The A-tract bending model is disqualified on two grounds: (i) tilt-wedge bending within A-tracts is incompatible with the observed direction of curvature; (ii) roll-wedge bending within A-tracts is contradicted by every crystal structure analysis, and is inconsistent with gel retardation results for (G-C-A-A-A-A-T-T-T-T)n and for (A-A-A-A-A-T-T-T-T-T)n. (2) The junction bend model is contradicted by crystallography because: (i) the inclination of base-pairs does not change between A-tract and non-A-tract regions of helix; and (ii) the observed bends at GC/AT junctions are roll-wedge bends, not tilt-wedge as the junction bend model demands. (3) The non-A-tract bending model is consistent with both gel retardation data and with X-ray crystallography, and must be regarded as the only consistent model for A-tract bending.
| + | [[Category: Kaczor-Grzeskowiak M]] |
| - | | + | |
| - | ==About this Structure== | + | |
| - | Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=167D OCA]. | + | |
| - | | + | |
| - | ==Reference== | + | |
| - | The crystal structure of C-C-A-T-T-A-A-T-G-G. Implications for bending of B-DNA at T-A steps., Goodsell DS, Kaczor-Grzeskowiak M, Dickerson RE, J Mol Biol. 1994 May 27;239(1):79-96. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8196049 8196049]
| + | |
| - | [[Category: Dickerson, R E.]] | + | |
| - | [[Category: Goodsell, D S.]] | + | |
| - | [[Category: Kaczor-Grzeskowiak, M.]] | + | |
| - | [[Category: B-dna]] | + | |
| - | [[Category: Double helix]] | + | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 09:32:15 2008''
| + | |
