7ZCG image
Entry Detail
PDB ID:
7ZCG
EMDB ID:
Title:
CHMP2A-CHMP3 heterodimer (430 Angstrom diameter)
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2022-03-28
Release Date:
2023-01-18
Method Details:
Experimental Method:
Resolution:
3.30 Å
Aggregation State:
FILAMENT
Reconstruction Method:
HELICAL
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Charged multivesicular body protein 3
Chain IDs:B (auth: A)
Chain Length:159
Number of Molecules:1
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Charged multivesicular body protein 2a
Chain IDs:A (auth: B)
Chain Length:147
Number of Molecules:1
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural basis of CHMP2A-CHMP3 ESCRT-III polymer assembly and membrane cleavage.
Nat.Struct.Mol.Biol. 30 81 90 (2023)
PMID: 36604498 DOI: 10.1038/s41594-022-00867-8

Abstact

The endosomal sorting complex required for transport (ESCRT) is a highly conserved protein machinery that drives a divers set of physiological and pathological membrane remodeling processes. However, the structural basis of ESCRT-III polymers stabilizing, constricting and cleaving negatively curved membranes is yet unknown. Here we present cryo-EM structures of membrane-coated CHMP2A-CHMP3 filaments from Homo sapiens of two different diameters at 3.3 and 3.6 Å resolution. The structures reveal helical filaments assembled by CHMP2A-CHMP3 heterodimers in the open ESCRT-III conformation, which generates a partially positive charged membrane interaction surface, positions short N-terminal motifs for membrane interaction and the C-terminal VPS4 target sequence toward the tube interior. Inter-filament interactions are electrostatic, which may facilitate filament sliding upon VPS4-mediated polymer remodeling. Fluorescence microscopy as well as high-speed atomic force microscopy imaging corroborate that VPS4 can constrict and cleave CHMP2A-CHMP3 membrane tubes. We therefore conclude that CHMP2A-CHMP3-VPS4 act as a minimal membrane fission machinery.

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Primary Citation of related structures