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| Line 8: |
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| <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8qlp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8qlp OCA], [https://pdbe.org/8qlp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8qlp RCSB], [https://www.ebi.ac.uk/pdbsum/8qlp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8qlp ProSAT]</span></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=8qlp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8qlp OCA], [https://pdbe.org/8qlp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8qlp RCSB], [https://www.ebi.ac.uk/pdbsum/8qlp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8qlp ProSAT]</span></td></tr> |
| </table> | | </table> |
| <div style="background-color:#fffaf0;">
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| == Publication Abstract from PubMed ==
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| In both prokaryotic and eukaryotic innate immune systems, TIR domains function as NADases that degrade the key metabolite NAD+ or generate signaling molecules. Catalytic activation of TIR domains requires oligomerization, but how this is achieved varies in distinct immune systems. In the Short prokaryotic Argonaute (pAgo)/TIR-APAZ (SPARTA) immune system, TIR NADase activity is triggered upon guide RNA-mediated recognition of invading DNA by an unknown mechanism. Here, we describe cryo-EM structures of SPARTA in the inactive monomeric and target DNA-activated tetrameric states. The monomeric SPARTA structure reveals that in the absence of target DNA, a C-terminal tail of TIR-APAZ occupies the nucleic acid binding cleft formed by the pAgo and TIR-APAZ subunits, inhibiting SPARTA activation. In the active tetrameric SPARTA complex, guide RNA-mediated target DNA binding displaces the C-terminal tail and induces conformational changes in pAgo that facilitate SPARTA-SPARTA dimerization. Concurrent release and rotation of one TIR domain allow it to form a composite NADase catalytic site with the other TIR domain within the dimer, and generate a self-complementary interface that mediates cooperative tetramerization. Combined, this study provides critical insights into the structural architecture of SPARTA and the molecular mechanism underlying target DNA-dependent oligomerization and catalytic activation.
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| Target DNA-dependent activation mechanism of the prokaryotic immune system SPARTA.,Finocchio G, Koopal B, Potocnik A, Heijstek C, Westphal AH, Jinek M, Swarts DC Nucleic Acids Res. 2024 Jan 15:gkad1248. doi: 10.1093/nar/gkad1248. PMID:38224450<ref>PMID:38224450</ref>
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| From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
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| </div>
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| <div class="pdbe-citations 8qlp" style="background-color:#fffaf0;"></div>
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| == References ==
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| <references/>
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| __TOC__ | | __TOC__ |
| </StructureSection> | | </StructureSection> |
