View source for 9cz2


==Cryo-EM structure of a nautilus-like HflK/C assembly in complex with FtsH AAA protease==
<StructureSection load='9cz2' size='340' side='right'caption='[[9cz2]], [[Resolution|resolution]] 4.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9cz2]] is a 36 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_BL21 Escherichia coli BL21]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9CZ2 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9CZ2 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]] 4.4&#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=9cz2 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9cz2 OCA], [https://pdbe.org/9cz2 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9cz2 RCSB], [https://www.ebi.ac.uk/pdbsum/9cz2 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9cz2 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/HFLK_ECOLI HFLK_ECOLI] HflC and HflK help govern the stability of phage lambda cII protein, and thereby control the lysogenization frequency of phage lambda. HflKC inhibits the SecY-degrading activity of FtsH, possibly helping quality control of integral membrane proteins.<ref>PMID:8947034</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The AAA protease FtsH associates with HflK/C subunits to form a megadalton-size complex that spans the inner membrane and extends into the periplasm of E. coli. How this bacterial complex and homologous assemblies in eukaryotic organelles recruit, extract, and degrade membrane-embedded substrates is unclear. Following the overproduction of protein components, recent cryo-EM structures showed symmetric HflK/C cages surrounding FtsH in a manner proposed to inhibit the degradation of membrane-embedded substrates. Here, we present structures of native protein complexes, in which HflK/C instead forms an asymmetric nautilus-shaped assembly with an entryway for membrane-embedded substrates to reach and be engaged by FtsH. Consistent with this nautilus-like structure, proteomic assays suggest that HflK/C enhances FtsH degradation of certain membrane-embedded substrates. Membrane curvature in our FtsH*HflK/C complexes is opposite that of surrounding membrane regions, a property that correlates with lipid scramblase activity and possibly with FtsH's function in the degradation of membrane-embedded proteins.

An asymmetric nautilus-like HflK/C assembly controls FtsH proteolysis of membrane proteins.,Ghanbarpour A, Telusma B, Powell BM, Zhang JJ, Bolstad I, Vargas C, Keller S, Baker TA, Sauer RT, Davis JH EMBO J. 2025 May;44(9):2501-2513. doi: 10.1038/s44318-025-00408-1. Epub 2025 Mar , 13. PMID:40082723<ref>PMID:40082723</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9cz2" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli BL21]]
[[Category: Large Structures]]
[[Category: Davis JH]]
[[Category: Ghanbarpour A]]
[[Category: Sauer RT]]