9QOO | pdb_00009qoo

Composite model: Ternary complex of the human 20S proteasome in complex with Importin-9 and two homodimers of Akirin-2

• PDB DOI: https://doi.org/10.2210/pdb9QOO/pdb
• EM Map EMD-53265: EMDB EMDataResource

• Classification: PROTEIN TRANSPORT
• Organism(s): Homo sapiens
• Expression System: Escherichia coli, Spodoptera frugiperda
• Mutation(s): No 


• Deposited: 2025-03-26 Released: 2026-01-28 
• Deposition Author(s): Brunner, H.L., Grundmann, L., David, H.
• Funding Organization(s): H2020 Marie Curie Actions of the European Commission, Austrian Science Fund

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Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.30 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

A multivalent adaptor mechanism drives the nuclear import of proteasomes

Brunner, H., Kalis, R.W., Grundmann, L., Hodakova, Z., Koskova, Z., Grishkovskaya, I., de Almeida, M., Hinterndorfer, M., Hoefflin, S., Andersch, F., Kotisch, H., Dickmanns, A., Cuylen-Haering, S., Zuber, J., Haselbach, D.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 12-mer - A2B1C1D1E1F1G1H1I1J1K1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 12-mer - A7B2C2D1 

Biological assembly 1 assigned by authors and generated by (software)

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 401.48 kDa 
• Atom Count: 20,499 
• Modeled Residue Count: 2,867 
• Deposited Residue Count: 3,601 
• Unique protein chains: 9

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Importin-9	A	1,041	Homo sapiens	Mutation(s): 0  Gene Names: IPO9, IMP9, KIAA1192, RANBP9, HSPC273
UniProt & NIH Common Fund Data Resources
Find proteins for Q96P70 (Homo sapiens) Explore Q96P70  Go to UniProtKB:  Q96P70
PHAROS:  Q96P70 GTEx:  ENSG00000198700

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Akirin-2	B, C, D, G [auth I]	203	Homo sapiens	Mutation(s): 0  Gene Names: AKIRIN2, C6orf166
UniProt & NIH Common Fund Data Resources
Find proteins for Q53H80 (Homo sapiens) Explore Q53H80  Go to UniProtKB:  Q53H80
PHAROS:  Q53H80 GTEx:  ENSG00000135334

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-3	E [auth F]	255	Homo sapiens	Mutation(s): 0  Gene Names: PSMA3, HC8, PSC8
UniProt & NIH Common Fund Data Resources
Find proteins for P25788 (Homo sapiens) Explore P25788  Go to UniProtKB:  P25788
PHAROS:  P25788 GTEx:  ENSG00000100567

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-6	F [auth G]	246	Homo sapiens	Mutation(s): 0  Gene Names: PSMA6, PROS27
UniProt & NIH Common Fund Data Resources
Find proteins for P60900 (Homo sapiens) Explore P60900  Go to UniProtKB:  P60900
PHAROS:  P60900 GTEx:  ENSG00000100902

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-2	H [auth O]	234	Homo sapiens	Mutation(s): 0  Gene Names: PSMA2, HC3, PSC3
UniProt & NIH Common Fund Data Resources
Find proteins for P25787 (Homo sapiens) Explore P25787  Go to UniProtKB:  P25787
PHAROS:  P25787 GTEx:  ENSG00000106588

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-4	I [auth P]	261	Homo sapiens	Mutation(s): 0  Gene Names: PSMA4, HC9, PSC9
UniProt & NIH Common Fund Data Resources
Find proteins for P25789 (Homo sapiens) Explore P25789  Go to UniProtKB:  P25789
PHAROS:  P25789 GTEx:  ENSG00000041357

Entity ID: 7
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-7	J [auth Q]	248	Homo sapiens	Mutation(s): 0  Gene Names: PSMA7, HSPC
UniProt & NIH Common Fund Data Resources
Find proteins for O14818 (Homo sapiens) Explore O14818  Go to UniProtKB:  O14818
PHAROS:  O14818 GTEx:  ENSG00000101182

Entity ID: 8
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-5	K [auth R]	241	Homo sapiens	Mutation(s): 0  Gene Names: PSMA5
UniProt & NIH Common Fund Data Resources
Find proteins for P28066 (Homo sapiens) Explore P28066  Go to UniProtKB:  P28066
PHAROS:  P28066 GTEx:  ENSG00000143106

Entity ID: 9
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-1	L [auth S]	263	Homo sapiens	Mutation(s): 0  Gene Names: PSMA1, HC2, NU, PROS30, PSC2
UniProt & NIH Common Fund Data Resources
Find proteins for P25786 (Homo sapiens) Explore P25786  Go to UniProtKB:  P25786
PHAROS:  P25786 GTEx:  ENSG00000129084

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.30 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2026-01-28 
Deposition Author(s): Brunner, H.L., Grundmann, L., David, H.

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Funding Organization	Location	Grant Number
H2020 Marie Curie Actions of the European Commission	European Union	847548
Austrian Science Fund	Austria	10.55776/F79

Revision History  

• Version 1.0: 2026-01-28
  Type: Initial release