2i0q
From Proteopedia
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| - | [[Image:2i0q.png|left|200px]] | ||
| - | + | ==Crystal structure of a telomere single-strand DNA-protein complex from O. nova with full-length alpha and beta telomere proteins== | |
| + | <StructureSection load='2i0q' size='340' side='right'caption='[[2i0q]], [[Resolution|resolution]] 1.91Å' scene=''> | ||
| + | == Structural highlights == | ||
| + | <table><tr><td colspan='2'>[[2i0q]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Sterkiella_nova Sterkiella nova]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I0Q OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2I0Q FirstGlance]. <br> | ||
| + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.91Å</td></tr> | ||
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene></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=2i0q FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i0q OCA], [https://pdbe.org/2i0q PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2i0q RCSB], [https://www.ebi.ac.uk/pdbsum/2i0q PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2i0q ProSAT]</span></td></tr> | ||
| + | </table> | ||
| + | == Function == | ||
| + | [https://www.uniprot.org/uniprot/TEBA_STENO TEBA_STENO] May function as protective capping of the single-stranded telomeric overhang. May also participate in telomere length regulation during DNA replication. Binds specifically to the T4G4-containing extension on the 3'strand and protects this region of the telomere from nuclease digestion and chemical modification. | ||
| + | == Evolutionary Conservation == | ||
| + | [[Image:Consurf_key_small.gif|200px|right]] | ||
| + | Check<jmol> | ||
| + | <jmolCheckbox> | ||
| + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i0/2i0q_consurf.spt"</scriptWhenChecked> | ||
| + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | ||
| + | <text>to colour the structure by Evolutionary Conservation</text> | ||
| + | </jmolCheckbox> | ||
| + | </jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2i0q ConSurf]. | ||
| + | <div style="clear:both"></div> | ||
| + | <div style="background-color:#fffaf0;"> | ||
| + | == Publication Abstract from PubMed == | ||
| + | In Sterkiella nova, alpha and beta telomere proteins bind cooperatively with single-stranded DNA to form a ternary alpha.beta.DNA complex. Association of telomere protein subunits is DNA-dependent, and alpha-beta association enhances DNA affinity. To further understand the molecular basis for binding cooperativity, we characterized several possible stepwise assembly pathways using isothermal titration calorimetry. In one path, alpha and DNA first form a stable alpha.DNA complex followed by the addition of beta in a second step. Binding energy accumulates with nearly equal free energy of association for each of these steps. Heat capacity is nonetheless dramatically different, with DeltaCp = -305 +/- 3 cal mol(-1) K(-1) for alpha binding with DNA and DeltaCp = -2010 +/- 20 cal mol(-1) K(-1) for the addition of beta to complete the alpha.beta.DNA complex. By examining alternate routes including titration of single-stranded DNA with a preformed alpha.beta complex, a significant portion of binding energy and heat capacity could be assigned to structural reorganization involving protein-protein interactions and repositioning of the DNA. Structural reorganization probably affords a mechanism to regulate high affinity binding of telomere single-stranded DNA with important implications for telomere biology. Regulation of telomere complex dissociation is thought to involve post-translational modifications in the lysine-rich C-terminal portion of beta. We observed no difference in binding energetics or crystal structure when comparing complexes prepared with full-length beta or a C-terminally truncated form, supporting interesting parallels between the intrinsically disordered regions of histones and this portion of beta. | ||
| - | + | Structural reorganization and the cooperative binding of single-stranded telomere DNA in Sterkiella nova.,Buczek P, Horvath MP J Biol Chem. 2006 Dec 29;281(52):40124-34. Epub 2006 Nov 2. PMID:17082188<ref>PMID:17082188</ref> | |
| - | + | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |
| - | + | </div> | |
| - | + | <div class="pdbe-citations 2i0q" style="background-color:#fffaf0;"></div> | |
| - | + | == References == | |
| - | + | <references/> | |
| - | == | + | __TOC__ |
| - | < | + | </StructureSection> |
| + | [[Category: Large Structures]] | ||
[[Category: Sterkiella nova]] | [[Category: Sterkiella nova]] | ||
| - | [[Category: Buczek | + | [[Category: Buczek P]] |
| - | [[Category: Horvath | + | [[Category: Horvath MP]] |
| - | + | ||
| - | + | ||
Current revision
Crystal structure of a telomere single-strand DNA-protein complex from O. nova with full-length alpha and beta telomere proteins
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