View source for 3u4z


==Crystal Structure of the Tetrahymena telomerase processivity factor Teb1 OB-B==
<StructureSection load='3u4z' size='340' side='right'caption='[[3u4z]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3u4z]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Tetth Tetth]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3U4Z OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3U4Z FirstGlance]. <br>
</td></tr><tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[3u4v|3u4v]], [[3u50|3u50]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">TAP82 ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=5911 TETTH])</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=3u4z FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3u4z OCA], [https://pdbe.org/3u4z PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3u4z RCSB], [https://www.ebi.ac.uk/pdbsum/3u4z PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3u4z ProSAT]</span></td></tr>
</table>
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== Publication Abstract from PubMed ==
Telomerase copies its internal RNA template to synthesize telomeric DNA repeats. Unlike other polymerases, telomerase can retain its single-stranded product through multiple rounds of template dissociation and repositioning to accomplish repeat addition processivity (RAP). Tetrahymena telomerase holoenzyme RAP depends on a subunit, Teb1, with autonomous DNA-binding activity. Sequence homology and domain modeling suggest that Teb1 is a paralog of RPA70C, the largest subunit of the single-stranded DNA-binding factor replication protein (RPA), but unlike RPA, Teb1 binds DNA with high specificity for telomeric repeats. To understand the structural basis and significance of telomeric-repeat DNA recognition by Teb1, we solved crystal structures of three proposed Teb1 DNA-binding domains and defined amino acids of each domain that contribute to DNA interaction. Our studies indicate that two central Teb1 DNA-binding oligonucleotide/oligosaccharide-binding-fold domains, Teb1A and Teb1B, achieve high affinity and selectivity of telomeric-repeat recognition by principles similar to the telomere end-capping protein POT1 (protection of telomeres 1). An additional C-terminal Teb1 oligonucleotide/oligosaccharide-binding-fold domain, Teb1C, has features shared with the RPA70 C-terminal domain including a putative direct DNA-binding surface that is critical for high-RAP activity of reconstituted holoenzyme. The Teb1C zinc ribbon motif does not contribute to DNA binding but is nonetheless required for high-RAP activity, perhaps contributing to Teb1 physical association with the remainder of the holoenzyme. Our results suggest the biological model that high-affinity DNA binding by Teb1AB recruits holoenzyme to telomeres and subsequent Teb1C-DNA association traps product in a sliding-clamp-like manner that does not require high-affinity DNA binding for high stability of enzyme-product association.

Structural basis for Tetrahymena telomerase processivity factor Teb1 binding to single-stranded telomeric-repeat DNA.,Zeng Z, Min B, Huang J, Hong K, Yang Y, Collins K, Lei M Proc Natl Acad Sci U S A. 2011 Dec 20;108(51):20357-61. Epub 2011 Dec 5. PMID:22143754<ref>PMID:22143754</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Telomerase-associated protein|Telomerase-associated protein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Tetth]]
[[Category: Huang, J]]
[[Category: Lei, M]]
[[Category: Yang, Y]]
[[Category: Zeng, Z]]
[[Category: Dna binding protein]]
[[Category: Processivity factor]]
[[Category: Teb1]]
[[Category: Telomerase]]
[[Category: Tetrahymena]]