View source for 9uxh


==type II Lamassu, LmuACB with DNA==
<StructureSection load='9uxh' size='340' side='right'caption='[[9uxh]], [[Resolution|resolution]] 3.03&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9uxh]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Vibrio_cholerae Vibrio cholerae] and [https://en.wikipedia.org/wiki/Synthetic_construct Synthetic construct]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9UXH OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9UXH 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]] 3.03&#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=9uxh FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9uxh OCA], [https://pdbe.org/9uxh PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9uxh RCSB], [https://www.ebi.ac.uk/pdbsum/9uxh PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9uxh ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Bacteria have developed a variety of immune systems to combat phage infections. The Lamassu system is a prokaryotic immune system with a core conserved structural maintenance of chromosomes (SMC) superfamily protein LmuB and diverse effectors named LmuA, whose mechanism remains unclear. Here we present a series of cryo-electron microscopy structures of the type-I Lamassu complex from Bacillus cellulasensis and the type-II Lamassu complex from Vibrio cholerae, both in apo and dsDNA-bound states, revealing an unexpected stoichiometry and topological architecture distinct from canonical SMC complexes. Combined structural and biochemical analyses show how the nuclease effector LmuA is sequestered in an inactive monomeric form within the Lamassu complex and, upon sensing foreign DNA ends, dissociates and assembles into an active tetramer capable of DNA cleavage. Our findings elucidate the mechanism by which Lamassu systems detect viral replication and implement antiphage defense, highlighting the roles of SMC proteins in prokaryotic immunity.

Structural insights into type-I and type-II Lamassu antiphage systems.,Li M, Zhao X, Zhao X, Li D, Xiong W, Gao Z, Huang L, An L, Gao Y, Li S, Feng Y, Zhang K, Zhang Y Nat Chem Biol. 2026 Jan 2. doi: 10.1038/s41589-025-02102-z. PMID:41482579<ref>PMID:41482579</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9uxh" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Synthetic construct]]
[[Category: Vibrio cholerae]]
[[Category: Feng Y]]
[[Category: Li M]]
[[Category: Li S]]
[[Category: Zhang K]]
[[Category: Zhao X]]