View source for 5the


==Crystal structure of the C-terminal lobe of a budding yeast Argonaute==
<StructureSection load='5the' size='340' side='right'caption='[[5the]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5the]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BL21(DE3) Escherichia coli BL21(DE3)] and [https://en.wikipedia.org/wiki/Vanderwaltozyma_polyspora_DSM_70294 Vanderwaltozyma polyspora DSM 70294]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5THE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5THE 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]] 2.097&#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=5the FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5the OCA], [https://pdbe.org/5the PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5the RCSB], [https://www.ebi.ac.uk/pdbsum/5the PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5the ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A7TMA9_VANPO A7TMA9_VANPO] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Some gene transcripts have cellular functions as regulatory noncoding RNAs. For example, ~23 nucleotide (nt)-long small interfering RNAs (siRNAs) are loaded into Argonaute proteins. The resultant ribonucleoprotein assembly, the RNA-induced silencing complex (RISC), cleaves RNAs that are extensively base-paired with the loaded siRNA. To date, base complementarity is recognized as the major determinant of specific target cleavage (or slicing), but little is known about how Argonaute inspects base pairing before cleavage. A hallmark of Argonaute proteins is their bilobal structure, but despite the significance of this structure for curtailing slicing activity against mismatched targets, the molecular mechanism remains elusive. Here, our structural and functional studies of a bilobed yeast Argonaute protein and its isolated catalytic C-terminal lobe (C-lobe) revealed that the C-lobe alone retains almost all properties of bilobed Argonaute: siRNA-duplex loading, passenger cleavage/ejection, and siRNA-dependent RNA cleavage. A 2.1 A-resolution crystal structure revealed that the catalytic C-lobe mirrors the bilobed Argonaute in terms of guide-RNA recognition and that all requirements for transitioning to the catalytically active conformation reside in the C-lobe. Nevertheless, we found that in the absence of the N-terminal lobe (N-lobe), target RNAs are scanned for complementarity only at positions 5-14 on a 23-nt guide RNA before endonucleolytic cleavage, thereby allowing for some off-target cleavage. Of note, acquisition of an N-lobe expanded the range of the guide RNA strand used for inspecting target complementarity to positions 2-23. These findings offer clues to the evolution of the bilobal structure of catalytically active Argonaute proteins.

Structural and functional analyses reveal the contributions of the C- and N-lobes of Argonaute protein to selectivity of RNA target cleavage.,Dayeh DM, Kruithoff BC, Nakanishi K J Biol Chem. 2018 Mar 8. pii: RA117.001051. doi: 10.1074/jbc.RA117.001051. PMID:29519815<ref>PMID:29519815</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5the" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vanderwaltozyma polyspora DSM 70294]]
[[Category: Dayeh DM]]
[[Category: Nakanishi K]]