9CZ2 image
Entry Detail
PDB ID:
9CZ2
EMDB ID:
Keywords:
Title:
Cryo-EM structure of a nautilus-like HflK/C assembly in complex with FtsH AAA protease
Biological Source:
Source Organism:
Host Organism:
PDB Version:
Deposition Date:
2024-08-03
Release Date:
2024-11-13
Method Details:
Experimental Method:
Resolution:
4.40 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:ATP-dependent zinc metalloprotease FtsH
Chain IDs:Y (auth: A), Z (auth: B), AA (auth: C), BA (auth: D), CA (auth: E), DA (auth: F), EA (auth: G), FA (auth: H), GA (auth: I), HA (auth: J), IA (auth: K), JA (auth: L)
Chain Length:644
Number of Molecules:12
Biological Source:Escherichia coli BL21
Polymer Type:polypeptide(L)
Description:Modulator of FtsH protease HflK
Chain IDs:A (auth: XA), C (auth: XC), E (auth: XE), G (auth: XG), I (auth: XI), K (auth: XK), M (auth: XM), O (auth: XO), Q (auth: XQ), S (auth: XS), U (auth: XU), X (auth: XW)
Chain Length:419
Number of Molecules:12
Biological Source:Escherichia coli BL21
Polymer Type:polypeptide(L)
Description:Modulator of FtsH protease HflC
Chain IDs:B (auth: XB), D (auth: XD), F (auth: XF), H (auth: XH), J (auth: XJ), L (auth: XL), N (auth: XN), P (auth: XP), R (auth: XR), T (auth: XT), V (auth: XX), W (auth: XV)
Chain Length:334
Number of Molecules:12
Biological Source:Escherichia coli BL21
Ligand Molecules
Primary Citation
An asymmetric nautilus-like HflK/C assembly controls FtsH proteolysis of membrane proteins.
Embo J. 44 2501 2513 (2025)
PMID: 40082723 DOI: 10.1038/s44318-025-00408-1

Abstact

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.

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Primary Citation of related structures