View source for 9cs9


==KHNYN KH1-KH2==
<StructureSection load='9cs9' size='340' side='right'caption='[[9cs9]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9cs9]] 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=9CS9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9CS9 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]] 2.5&#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=9cs9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9cs9 OCA], [https://pdbe.org/9cs9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9cs9 RCSB], [https://www.ebi.ac.uk/pdbsum/9cs9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9cs9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KHNYN_HUMAN KHNYN_HUMAN] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Detecting viral infection is a key role of the innate immune system. The genomes of some RNA viruses have a high CpG dinucleotide content relative to most vertebrate cell RNAs, making CpGs a molecular marker of infection. The human zinc-finger antiviral protein (ZAP) recognizes CpG, mediates clearance of the foreign CpG-rich RNA, and causes attenuation of CpG-rich RNA viruses. While ZAP binds RNA, it lacks enzymatic activity that might be responsible for RNA degradation and thus requires interacting cofactors for its function. One of these cofactors, KHNYN, has a predicted nuclease domain. Using biochemical approaches, we found that the KHNYN NYN domain is a single-stranded RNA ribonuclease that does not have sequence specificity and digests RNA with or without CpG dinucleotides equivalently in vitro. We show that unlike most KH domains, the KHNYN KH domain does not bind RNA. Indeed, a crystal structure of the KH region revealed a double-KH domain with a negatively charged surface that accounts for the lack of RNA binding. Rather, the KHNYN C-terminal domain (CTD) interacts with the ZAP RNA-binding domain (RBD) to provide target RNA specificity. We define a minimal complex composed of the ZAP RBD and the KHNYN NYN-CTD and use a fluorescence polarization assay to propose a model for how this complex interacts with a CpG dinucleotide-containing RNA. In the context of the cell, this module would represent the minimum ZAP and KHNYN domains required for CpG-recognition and ribonuclease activity essential for attenuation of viruses with clusters of CpG dinucleotides.

A minimal complex of KHNYN and zinc-finger antiviral protein binds and degrades single-stranded RNA.,Yeoh ZC, Meagher JL, Kang CY, Bieniasz PD, Smith JL, Ohi MD Proc Natl Acad Sci U S A. 2024 Dec 24;121(52):e2415048121. doi: , 10.1073/pnas.2415048121. Epub 2024 Dec 18. PMID:39693345<ref>PMID:39693345</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9cs9" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Ohi MD]]
[[Category: Smith JL]]
[[Category: Yeoh ZC]]