9HMN image
Deposition Date 2024-12-09
Release Date 2025-03-05
Last Version Date 2025-07-02
Entry Detail
PDB ID:
9HMN
Keywords:
Title:
CryoEM structure of human 20S proteasome in complex with proteasome inhibitor Salinosporamid A
Biological Source:
Source Organism:
Homo sapiens (Taxon ID: 9606)
Method Details:
Experimental Method:
Resolution:
2.55 Å
Aggregation State:
PARTICLE
Reconstruction Method:
SINGLE PARTICLE
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-6
Gene (Uniprot):PSMA6
Chain IDs:A, O
Chain Length:246
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-2
Gene (Uniprot):PSMA2
Chain IDs:B, P
Chain Length:233
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-4
Gene (Uniprot):PSMA4
Chain IDs:C, Q
Chain Length:261
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-7
Gene (Uniprot):PSMA7
Chain IDs:K (auth: D), Y
Chain Length:248
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-5
Gene (Uniprot):PSMA5
Chain IDs:D (auth: E), R
Chain Length:241
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-1
Gene (Uniprot):PSMA1
Chain IDs:E (auth: F), S
Chain Length:263
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit alpha type-3
Gene (Uniprot):PSMA3
Chain IDs:F (auth: G), T
Chain Length:254
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-6
Gene (Uniprot):PSMB6
Chain IDs:L (auth: H), Z
Chain Length:205
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-7
Gene (Uniprot):PSMB7
Chain IDs:M (auth: I), AA (auth: a)
Chain Length:246
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-3
Gene (Uniprot):PSMB3
Chain IDs:G (auth: J), U
Chain Length:204
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-2
Gene (Uniprot):PSMB2
Chain IDs:H (auth: K), V
Chain Length:201
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-5
Gene (Uniprot):PSMB5
Chain IDs:N (auth: L), BA (auth: b)
Chain Length:233
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-1
Gene (Uniprot):PSMB1
Chain IDs:I (auth: M), W
Chain Length:213
Number of Molecules:2
Biological Source:Homo sapiens
Polymer Type:polypeptide(L)
Molecule:Proteasome subunit beta type-4
Gene (Uniprot):PSMB4
Chain IDs:J (auth: N), X
Chain Length:219
Number of Molecules:2
Biological Source:Homo sapiens
Ligand Molecules
Primary Citation
Structural Insights into Salinosporamide a Mediated Inhibition of the Human 20S Proteasome.
Molecules 30 ? ? (2025)
PMID: 40142161 DOI: 10.3390/molecules30061386

Abstact

The 20S proteasome, a critical component of the ubiquitin-proteasome system, plays a central role in regulating protein degradation in eukaryotic cells. Marizomib (MZB), also known as salinosporamide A, is a natural γ-lactam-β-lactone compound derived from Salinispora tropica and is a potent 20S proteasome covalent inhibitor with demonstrated anticancer properties. Its broad-spectrum inhibition of all three proteasome subunits and its ability to cross the blood-brain barrier has made it a promising therapeutic candidate for glioblastoma. In addition to this, MZB also demonstrates significant inhibition against the 20S proteasome of Trichomonas vaginalis (Tv20S), a protozoan parasite, suggesting its potential for parasitic treatments. Here, we present the cryo-EM structure of the human 20S proteasome in complex with MZB at 2.55 Å resolution. This structure reveals the binding mode of MZB to all six catalytic subunits within the two β-rings of the 20S proteasome, providing a detailed molecular understanding of its irreversible inhibitory mechanism. These findings enhance the therapeutic potential of MZB for both cancer and parasitic diseases at the molecular level and highlight marine-derived natural products in targeting the proteasome for therapeutic applications.

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Primary Citation of related structures