8CVR image
Entry Detail
PDB ID:
8CVR
EMDB ID:
Title:
Human 20S proteasome with MG-132
Biological Source:
Source Organism:
PDB Version:
Deposition Date:
2022-05-18
Release Date:
2022-11-02
Method Details:
Experimental Method:
Resolution:
2.70 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-6
Chain IDs:A, O
Chain Length:246
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-2
Chain IDs:B, P
Chain Length:264
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-4
Chain IDs:C, Q
Chain Length:261
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-7
Chain IDs:D, R
Chain Length:248
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-5
Chain IDs:E, S
Chain Length:241
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-1
Chain IDs:F, T
Chain Length:263
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit alpha type-3
Chain IDs:G, U
Chain Length:255
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-6
Chain IDs:H, V
Chain Length:205
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-7
Chain IDs:I, W
Chain Length:234
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-3
Chain IDs:J, X
Chain Length:205
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-2
Chain IDs:K, Y
Chain Length:201
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-5
Chain IDs:L, Z
Chain Length:204
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-1
Chain IDs:M, AA (auth: a)
Chain Length:246
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Description:Proteasome subunit beta type-4
Chain IDs:N, BA (auth: b)
Chain Length:264
Number of Molecules:2
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural insights into the human PA28-20S proteasome enabled by efficient tagging and purification of endogenous proteins.
Proc.Natl.Acad.Sci.USA 119 e2207200119 e2207200119 (2022)
PMID: 35858375 DOI: 10.1073/pnas.2207200119

Abstact

The ability to produce folded and functional proteins is a necessity for structural biology and many other biological sciences. This task is particularly challenging for numerous biomedically important targets in human cells, including membrane proteins and large macromolecular assemblies, hampering mechanistic studies and drug development efforts. Here we describe a method combining CRISPR-Cas gene editing and fluorescence-activated cell sorting to rapidly tag and purify endogenous proteins in HEK cells for structural characterization. We applied this approach to study the human proteasome from HEK cells and rapidly determined cryogenic electron microscopy structures of major proteasomal complexes, including a high-resolution structure of intact human PA28αβ-20S. Our structures reveal that PA28 with a subunit stoichiometry of 3α/4β engages tightly with the 20S proteasome. Addition of a hydrophilic peptide shows that polypeptides entering through PA28 are held in the antechamber of 20S prior to degradation in the proteolytic chamber. This study provides critical insights into an important proteasome complex and demonstrates key methodologies for the tagging of proteins from endogenous sources.

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Primary Citation of related structures