View source for 9ngu


==In situ cryo-EM structure of outer membrane cap (OMC) of the Legionella Dot/Icm T4SS machine==
<StructureSection load='9ngu' size='340' side='right'caption='[[9ngu]], [[Resolution|resolution]] 2.96&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9ngu]] is a 130 chain structure with sequence from [https://en.wikipedia.org/wiki/Legionella_pneumophila_subsp._pneumophila Legionella pneumophila subsp. pneumophila]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9NGU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9NGU 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]] 2.96&#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=9ngu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9ngu OCA], [https://pdbe.org/9ngu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9ngu RCSB], [https://www.ebi.ac.uk/pdbsum/9ngu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9ngu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q5ZS45_LEGPH Q5ZS45_LEGPH] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The Dot/Icm machine in Legionella pneumophila is one of the most versatile type IV secretion systems (T4SSs), with a remarkable capacity to translocate over 330 different effector proteins across the bacterial envelope into host cells. At least 27 Dot and Icm proteins are required for assembly and function of the system, yet the architecture and activation mechanism remain poorly understood at the molecular level. Here, we deploy cryo-electron microscopy to reveal in-situ structures of the Dot/Icm machine at near-atomic resolution. Importantly, two proteins essential for effector translocation, DotA and IcmX, form a pentameric protochannel at an inactive state. Upon activation, the DotA-IcmX protochannel undergoes extensive rearrangements to form an extended transenvelope passage capable of transporting effector proteins from the bacterial cytoplasm into host cells as revealed by cryo-electron tomography. Collectively, our findings suggest that the DotA-IcmX complex functions as the gatekeeper for effector translocation of the Dot/Icm T4SS.

In-situ structures of the Legionella Dot/Icm T4SS identify the DotA-IcmX complex as the gatekeeper for effector translocation.,Yue J, Heydari S, Park D, Chetrit D, Tachiyama S, Guo W, Botting JM, Wu S, Roy CR, Liu J bioRxiv [Preprint]. 2025 Jun 25:2025.06.23.660953. doi: , 10.1101/2025.06.23.660953. PMID:40666918<ref>PMID:40666918</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9ngu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Legionella pneumophila subsp. pneumophila]]
[[Category: Jun L]]
[[Category: Yue J]]