5FNA image
Deposition Date 2015-11-11
Release Date 2016-03-30
Last Version Date 2024-05-08
Entry Detail
PDB ID:
5FNA
Keywords:
Title:
Cryo-EM reconstruction of caspase-1 CARD
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Host Organism:
Method Details:
Experimental Method:
Resolution:
4.80 Å
Aggregation State:
FILAMENT
Reconstruction Method:
HELICAL
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Caspase-1
Gene (Uniprot):CASP1
Chain IDs:A, B, C, D, E, F, G, H
Chain Length:85
Number of Molecules:8
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Molecular Basis of Caspase-1 Polymerization and its Inhibition by a Novel Capping Mechanism
Nat.Struct.Mol.Biol. 23 416 ? (2016)
PMID: 27043298 DOI: 10.1038/NSMB.3199

Abstact

Inflammasomes are cytosolic caspase-1-activation complexes that sense intrinsic and extrinsic danger signals, and trigger inflammatory responses and pyroptotic cell death. Homotypic interactions among Pyrin domains and caspase recruitment domains (CARDs) in inflammasome-complex components mediate oligomerization into filamentous assemblies. Several cytosolic proteins consisting of only interaction domains exert inhibitory effects on inflammasome assembly. In this study, we determined the structure of the human caspase-1 CARD domain (caspase-1(CARD)) filament by cryo-electron microscopy and investigated the biophysical properties of two caspase-1-like CARD-only proteins: human inhibitor of CARD (INCA or CARD17) and ICEBERG (CARD18). Our results reveal that INCA caps caspase-1 filaments, thereby exerting potent inhibition with low-nanomolar Ki on caspase-1(CARD) polymerization in vitro and inflammasome activation in cells. Whereas caspase-1(CARD) uses six complementary surfaces of three types for filament assembly, INCA is defective in two of the six interfaces and thus terminates the caspase-1 filament.

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Primary Citation of related structures