View source for 9nyg


==LmuABC-DNA==
<StructureSection load='9nyg' size='340' side='right'caption='[[9nyg]], [[Resolution|resolution]] 2.93&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9nyg]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9NYG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9NYG 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]] 2.93&#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=9nyg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9nyg OCA], [https://pdbe.org/9nyg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9nyg RCSB], [https://www.ebi.ac.uk/pdbsum/9nyg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9nyg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A060KYQ4_VIBCL A0A060KYQ4_VIBCL] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacterial immune systems exhibit remarkable diversity and modularity, as a consequence of the continuous selective pressures imposed by phage predation. Despite recent mechanistic advances, the evolutionary origins of many antiphage immune systems remain elusive, especially for those that encode homologs of the structural maintenance of chromosomes (SMC) superfamily, which are essential for chromosome maintenance and DNA repair across domains of life. Here, we elucidate the structural basis and evolutionary emergence of Lamassu, a bacterial immune system family featuring diverse effectors but a core conserved SMC-like sensor. Using cryo-EM, we determined structures of the Vibrio cholerae Lamassu complex in both apo- and dsDNA-bound states, revealing unexpected stoichiometry and topological architectures. We further demonstrate how Lamassu specifically senses dsDNA ends in vitro and phage replication origins in vivo, thereby triggering the formation of LmuA tetramers that activate its Cap4 nuclease domain. Our findings reveal that Lamassu evolved via exaptation of the bacterial Rad50-Mre11 DNA repair system to form a compact, modular sensor for viral replication, exemplifying how cellular machinery can be co-opted for novel immune functions.

Structural basis for Lamassu-based antiviral immunity and its evolution from DNA repair machinery.,Haudiquet M, Chakravarti A, Zhang Z, Ramirez JL, Herrero Del Valle A, Olinares PDB, Lavenir R, Ahmed MA, de la Cruz MJ, Chait BT, Sternberg SH, Bernheim A, Patel DJ Proc Natl Acad Sci U S A. 2025 Nov 25;122(47):e2519643122. doi: , 10.1073/pnas.2519643122. Epub 2025 Nov 18. PMID:41252147<ref>PMID:41252147</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9nyg" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Vibrio cholerae]]
[[Category: Chakravarti A]]
[[Category: Zhang Z]]