View source for 9k4a


==Cryo-EM structure of depolymerase S2-4 from Klebsiella phage K64-1==
<StructureSection load='9k4a' size='340' side='right'caption='[[9k4a]], [[Resolution|resolution]] 2.24&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9k4a]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Klebsiella_phage_K64-1 Klebsiella phage K64-1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9K4A OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9K4A 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]] 2.24&#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=9k4a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9k4a OCA], [https://pdbe.org/9k4a PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9k4a RCSB], [https://www.ebi.ac.uk/pdbsum/9k4a PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9k4a ProSAT]</span></td></tr>
</table>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The infection rate and drug resistance of Klebsiella pneumoniae containing capsular polysaccharides (CPSs) have been increasing annually, resulting in severe human and animal infections. Depolymerases derived from bacteriophages can degrade CPSs and thus hold potential for treating bacterial infections. However, little is known about the mechanism by which K. pneumoniae phage depolymerases hydrolyze CPSs. In this study, the S2-4 encoded by the phage PhiK64 was identified as a potent depolymerase against K1 serotype Klebsiella CPSs. Cryo-electron microscopy structural analysis revealed that S2-4 forms a homotrimer with a spindle-like structure comprising a particle-binding domain, a core receptor-binding domain, an insertion domain, and a C-terminal domain. The results of structural assays suggest that S2-4 possesses multiple catalytic centers, which may contribute to its potent depolymerase activity. S2-4 inhibited K. pneumoniae biofilm formation, disrupted preformed biofilms, and enhanced macrophage adhesion and phagocytosis in depolymerase-treated bacteria. In a murine model, a single dose of 5â¯microg of S2-4 provided full protection against bacterial infection, underscoring the potent depolymerase activity of S2-4. These results indicate that S2-4 is a potent depolymerase against K1 serotype Klebsiella CPSs and has the potential to be a promising candidate for the clinical control of K. pneumoniae infections.

Characterization of the phage PhiK64 depolymerase S2-4 and its therapeutic effect against K1 serotype Klebsiella pneumoniae.,Zhao R, Du T, Ji Y, Ren Z, Jiang S, Ru H, Gu J Microbiol Res. 2026 Jun;307:128475. doi: 10.1016/j.micres.2026.128475. Epub 2026 , Feb 13. PMID:41702136<ref>PMID:41702136</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9k4a" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Klebsiella phage K64-1]]
[[Category: Large Structures]]
[[Category: Du T]]
[[Category: Gu J]]
[[Category: Ren Z]]
[[Category: Ru H]]
[[Category: Zhao R]]