View source for 9ftw


==Crystal structure of calcium-activated EndoU==
<StructureSection load='9ftw' size='340' side='right'caption='[[9ftw]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9ftw]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9FTW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9FTW 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]] 1.65&#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=9ftw FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9ftw OCA], [https://pdbe.org/9ftw PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9ftw RCSB], [https://www.ebi.ac.uk/pdbsum/9ftw PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9ftw ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ENDOU_HUMAN ENDOU_HUMAN] Endoribonuclease that cleaves single-stranded RNAs at 5' of uridylates and releases a product with a 2',3'-cyclic phosphate at the 3'-end. The UU and GU sites are more efficiently cleaved than CU and AU sites.<ref>PMID:18936097</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Ribonucleases (RNases) are ubiquitous enzymes that process or degrade RNA, essential for cellular functions and immune responses. The EndoU-like superfamily includes endoribonucleases conserved across bacteria, eukaryotes, and certain viruses, with an ancient evolutionary link to the ribonuclease A-like superfamily. Both bacterial EndoU and animal RNase A share a similar fold and function independently of cofactors. In contrast, the eukaryotic EndoU catalytic domain requires divalent metal ions for catalysis, possibly due to an N-terminal extension near the catalytic core. In this study, we used biophysical and computational techniques along with in vitro assays to investigate the calcium-dependent activation of human EndoU. We determined the crystal structure of EndoU bound to calcium and found that calcium binding remote from the catalytic triad triggers water-mediated intramolecular signaling and structural changes, activating the enzyme through allostery. Calcium-binding involves residues from both the catalytic core and the N-terminal extension, indicating that the N-terminal extension interacts with the catalytic core to modulate activity in response to calcium. Our findings suggest that similar mechanisms may be present across all eukaryotic EndoUs, highlighting a unique evolutionary adaptation that connects endoribonuclease activity to cellular signaling in eukaryotes.

Molecular Basis for the Calcium-Dependent Activation of the Ribonuclease EndoU.,Malard F, Dias K, Baudy M, Thore S, Vialet B, Barthelemy P, Fribourg S, Karginov FV, Campagne S Res Sq [Preprint]. 2024 Jul 15:rs.3.rs-4654759. doi: 10.21203/rs.3.rs-4654759/v1. PMID:39070628<ref>PMID:39070628</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9ftw" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Campagne S]]
[[Category: Fribourg S]]