View source for 10uj


==Hna Monomer==
<StructureSection load='10uj' size='340' side='right'caption='[[10uj]], [[Resolution|resolution]] 3.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[10uj]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Sinorhizobium_meliloti Sinorhizobium meliloti]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=10UJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=10UJ 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]] 3.9&#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=10uj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=10uj OCA], [https://pdbe.org/10uj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=10uj RCSB], [https://www.ebi.ac.uk/pdbsum/10uj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=10uj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q92XN4_RHIME Q92XN4_RHIME] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Prokaryotic organisms have evolved unique strategies to acquire immunity against the constant threat of bacteriophage (phage) and mobile genetic elements. Hna is a broadly distributed anti-phage immune system that confers resistance against diverse phage by eliciting an abortive infection response. Using a combination of biochemistry, cryo-electron microscopy, and single-molecule fluorescence imaging, we reveal that Hna functions as a 3'-5' single-stranded DNA exonuclease that forms an auto-inhibited dimer under physiological ATP concentrations. Biochemical and mutational analyses demonstrate that Hna catalytic outputs are governed by kinetic partitioning between ATPase and nuclease active sites. Disruption of this balance enhances DNA cleavage and causes cellular toxicity. Furthermore, we show that a phage-encoded single-stranded DNA-binding protein (5 A SSB) destabilizes the autoinhibited Hna dimer and shifts catalytic partitioning toward dysregulated nuclease activation. Conversely, phage escape mutants encode SSB variants that evade Hna surveillance by adopting higher order stoichiometries with enhanced DNA binding affinity. Our work establishes the molecular basis of Hna-mediated anti-phage activity and provides insights into how phage-encoded proteins can directly stimulate a bacterial immune response.

Phage-encoded factor stimulates DNA degradation by the Hna anti-phage defense system.,Hooper MM, Hoover BT, Zhang H, Franco AS, Finkelstein IJ, Taylor DW Nat Commun. 2026 May 18. doi: 10.1038/s41467-026-73157-2. PMID:42151145<ref>PMID:42151145</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 10uj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Sinorhizobium meliloti]]
[[Category: Hooper M]]