View source for 3oiq


==Crystal structure of yeast telomere protein Cdc13 OB1 and the catalytic subunit of DNA polymerase alpha Pol1==
<StructureSection load='3oiq' size='340' side='right'caption='[[3oiq]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3oiq]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3OIQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3OIQ 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]] 2.4&#8491;</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=3oiq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3oiq OCA], [https://pdbe.org/3oiq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3oiq RCSB], [https://www.ebi.ac.uk/pdbsum/3oiq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3oiq ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CDC13_YEAST CDC13_YEAST] Single-stranded telomeric DNA-binding protein that regulates telomere replication. Has a role in both positive and negative regulation. Promotes [TG(1-3)] strand lengthening via interaction with EST1. Promotes [C(1-3)A] strand re-synthesis by DNA polymerase alpha via interaction with POL1. Negatively regulates telomere elongation of the G strand via binding with STN1 thereby inhibiting telomerase activity.<ref>PMID:11230149</ref> <ref>PMID:11390652</ref> <ref>PMID:10898792</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Budding yeast Cdc13-Stn1-Ten1 (CST) complex plays an essential role in telomere protection and maintenance, and has been proposed to be a telomere-specific replication protein A (RPA)-like complex. Previous genetic and structural studies revealed a close resemblance between Stn1-Ten1 and RPA32-RPA14. However, the relationship between Cdc13 and RPA70, the largest subunit of RPA, has remained unclear. Here, we report the crystal structure of the N-terminal OB (oligonucleotide/oligosaccharide binding) fold of Cdc13. Although Cdc13 has an RPA70-like domain organization, the structures of Cdc13 OB folds are significantly different from their counterparts in RPA70, suggesting that they have distinct evolutionary origins. Furthermore, our structural and biochemical analyses revealed unexpected dimerization by the N-terminal OB fold and showed that homodimerization is probably a conserved feature of all Cdc13 proteins. We also uncovered the structural basis of the interaction between the Cdc13 N-terminal OB fold and the catalytic subunit of DNA polymerase alpha (Pol1), and demonstrated a role for Cdc13 dimerization in Pol1 binding. Analysis of the phenotypes of mutants defective in Cdc13 dimerization and Cdc13-Pol1 interaction revealed multiple mechanisms by which dimerization regulates telomere lengths in vivo. Collectively, our findings provide novel insights into the mechanisms and evolution of Cdc13.

Structural bases of dimerization of yeast telomere protein Cdc13 and its interaction with the catalytic subunit of DNA polymerase alpha,Sun J, Yang Y, Wan K, Mao N, Yu TY, Lin YC, Dezwaan DC, Freeman BC, Lin JJ, Lue NF, Lei M Cell Res. 2010 Sep 28. PMID:20877309<ref>PMID:20877309</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3oiq" style="background-color:#fffaf0;"></div>

==See Also==
*[[DNA polymerase 3D structures|DNA polymerase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae]]
[[Category: DeZwaan DC]]
[[Category: Freeman BC]]
[[Category: Lei M]]
[[Category: Lin JJ]]
[[Category: Lin YC]]
[[Category: Lue NF]]
[[Category: Mao N]]
[[Category: Sun J]]
[[Category: Wan K]]
[[Category: Yang Y]]
[[Category: Yu TY]]