View source for 1k8g


==Crystal Structure of the N-terminal domain of Oxytricha nova telomere end binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA==
<StructureSection load='1k8g' size='340' side='right'caption='[[1k8g]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1k8g]] is a 5 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=1K8G OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1K8G 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1k8g FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k8g OCA], [https://pdbe.org/1k8g PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1k8g RCSB], [https://www.ebi.ac.uk/pdbsum/1k8g PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1k8g 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/k8/1k8g_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=1k8g ConSurf].
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== Publication Abstract from PubMed ==
Oxytricha nova telomere end-binding protein specifically recognizes and caps single strand (T(4)G(4))(n) telomeric DNA at the very 3'-ends of O. nova macronuclear chromosomes. Proteins homologous to the N-terminal domain of OnTEBP alpha subunit have now been identified in Oxytricha trifallax, Stylonychia mytilis, Euplotes crassus, Schizosaccharomyces pombe, and Homo sapiens, suggesting that this protein is widely distributed in eukaryotes. We describe here the crystal structures of the N-terminal single-stranded DNA (ssDNA)-binding domain of O. nova telomere end-binding protein alpha subunit both uncomplexed and complexed with single strand telomeric DNA. These structures show how the N-terminal domain of alpha alone, in the absence of the beta subunit and without alpha dimerization, can bind single-stranded telomeric DNA in a sequence-specific and 3'-end-specific manner. Furthermore, comparison of the uncomplexed and complexed forms of this protein shows that the ssDNA-binding site is largely pre-organized in the absence of ssDNA with modest, but interesting, rearrangements of amino acid side-chains that compose the ssDNA-binding site. The structures described here extend our understanding of structures of O. nova telomeric complexes by adding uncomplexed and complexed forms of monomeric alpha to previously described structures for (alpha 56/ssDNA)(2) dimer and alpha 56/beta 28/ssDNA ternary complexes. We believe that each of these four structures represent intermediates in an ordered assembly/disassembly pathway for O. nova telomeric complexes.

Crystal structure of the N-terminal domain of Oxytricha nova telomere end-binding protein alpha subunit both uncomplexed and complexed with telomeric ssDNA.,Classen S, Ruggles JA, Schultz SC J Mol Biol. 2001 Dec 14;314(5):1113-25. PMID:11743727<ref>PMID:11743727</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1k8g" style="background-color:#fffaf0;"></div>

==See Also==
*[[End-binding protein|End-binding protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Sterkiella nova]]
[[Category: Classen S]]
[[Category: Ruggles JA]]
[[Category: Schultz SC]]