View source for 7tnx


==Cryo-EM structure of RIG-I in complex with p3dsRNA==
<StructureSection load='7tnx' size='340' side='right'caption='[[7tnx]], [[Resolution|resolution]] 3.54&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7tnx]] is a 3 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=7TNX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TNX FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.54&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GTP:GUANOSINE-5-TRIPHOSPHATE'>GTP</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=7tnx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7tnx OCA], [https://pdbe.org/7tnx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7tnx RCSB], [https://www.ebi.ac.uk/pdbsum/7tnx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7tnx ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/RIGI_HUMAN RIGI_HUMAN] Singleton-Merten dysplasia. The disease is caused by variants affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/RIGI_HUMAN RIGI_HUMAN] Innate immune receptor that senses cytoplasmic viral nucleic acids and activates a downstream signaling cascade leading to the production of type I interferons and pro-inflammatory cytokines (PubMed:15208624, PubMed:15708988, PubMed:16125763, PubMed:16127453, PubMed:16153868, PubMed:17190814, PubMed:18636086, PubMed:19122199, PubMed:19211564, PubMed:24366338, PubMed:28469175, PubMed:29117565, PubMed:31006531, PubMed:34935440, PubMed:35263596, PubMed:36793726). Forms a ribonucleoprotein complex with viral RNAs on which it homooligomerizes to form filaments (PubMed:15208624, PubMed:15708988). The homooligomerization allows the recruitment of RNF135 an E3 ubiquitin-protein ligase that activates and amplifies the RIG-I-mediated antiviral signaling in an RNA length-dependent manner through ubiquitination-dependent and -independent mechanisms (PubMed:28469175, PubMed:31006531). Upon activation, associates with mitochondria antiviral signaling protein (MAVS/IPS1) that activates the IKK-related kinases TBK1 and IKBKE which in turn phosphorylate the interferon regulatory factors IRF3 and IRF7, activating transcription of antiviral immunological genes including the IFN-alpha and IFN-beta interferons (PubMed:28469175, PubMed:31006531). Ligands include 5'-triphosphorylated ssRNAs and dsRNAs but also short dsRNAs (<1 kb in length) (PubMed:15208624, PubMed:15708988, PubMed:19576794, PubMed:19609254, PubMed:21742966). In addition to the 5'-triphosphate moiety, blunt-end base pairing at the 5'-end of the RNA is very essential (PubMed:15208624, PubMed:15708988, PubMed:19576794, PubMed:19609254, PubMed:21742966). Overhangs at the non-triphosphorylated end of the dsRNA RNA have no major impact on its activity (PubMed:15208624, PubMed:15708988, PubMed:19576794, PubMed:19609254, PubMed:21742966). A 3'overhang at the 5'triphosphate end decreases and any 5'overhang at the 5' triphosphate end abolishes its activity (PubMed:15208624, PubMed:15708988, PubMed:19576794, PubMed:19609254, PubMed:21742966). Detects both positive and negative strand RNA viruses including members of the families Paramyxoviridae: Human respiratory syncytial virus and measles virus (MeV), Rhabdoviridae: vesicular stomatitis virus (VSV), Orthomyxoviridae: influenza A and B virus, Flaviviridae: Japanese encephalitis virus (JEV), hepatitis C virus (HCV), dengue virus (DENV) and west Nile virus (WNV) (PubMed:21616437, PubMed:21884169). It also detects rotaviruses and reoviruses (PubMed:21616437, PubMed:21884169). Detects and binds to SARS-CoV-2 RNAs which is inhibited by m6A RNA modifications (Ref.70). Also involved in antiviral signaling in response to viruses containing a dsDNA genome such as Epstein-Barr virus (EBV) (PubMed:19631370). Detects dsRNA produced from non-self dsDNA by RNA polymerase III, such as Epstein-Barr virus-encoded RNAs (EBERs). May play important roles in granulocyte production and differentiation, bacterial phagocytosis and in the regulation of cell migration.<ref>PMID:15208624</ref> <ref>PMID:15708988</ref> <ref>PMID:16125763</ref> <ref>PMID:16127453</ref> <ref>PMID:16153868</ref> <ref>PMID:17190814</ref> <ref>PMID:18636086</ref> <ref>PMID:19122199</ref> <ref>PMID:19211564</ref> <ref>PMID:19576794</ref> <ref>PMID:19609254</ref> <ref>PMID:19631370</ref> <ref>PMID:21742966</ref> <ref>PMID:24366338</ref> <ref>PMID:28469175</ref> <ref>PMID:29117565</ref> <ref>PMID:31006531</ref> <ref>PMID:34935440</ref> <ref>PMID:35263596</ref> <ref>PMID:36793726</ref> [REFERENCE:70]<ref>PMID:21616437</ref> <ref>PMID:21884169</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
RIG-I is an essential innate immune receptor for detecting and responding to infection by RNA viruses. RIG-I specifically recognizes the unique molecular features of viral RNA molecules and selectively distinguishes them from closely related RNAs abundant in host cells. The physical basis for this exquisite selectivity is revealed through a series of high-resolution cryo-EM structures of RIG-I in complex with host and viral RNA ligands. These studies demonstrate that RIG-I actively samples double-stranded RNAs in the cytoplasm and distinguishes them by adopting two different types of protein folds. Upon binding viral RNA, RIG-I adopts a high-affinity conformation that is conducive to signaling, while host RNA induces an autoinhibited conformation that stimulates RNA release. By coupling protein folding with RNA binding selectivity, RIG-I distinguishes RNA molecules that differ by as little as one phosphate group, thereby explaining the molecular basis for selective antiviral sensing and the induction of autoimmunity upon RIG-I dysregulation.

The RIG-I receptor adopts two different conformations for distinguishing host from viral RNA ligands.,Wang W, Pyle AM Mol Cell. 2022 Nov 3;82(21):4131-4144.e6. doi: 10.1016/j.molcel.2022.09.029. Epub , 2022 Oct 21. PMID:36272408<ref>PMID:36272408</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7tnx" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Pyle AM]]
[[Category: Wang W]]