9SZV | pdb_00009szv

Co-chaperone Bag1-bound human 26S proteasome in SBAG1.3 state

• PDB DOI: https://doi.org/10.2210/pdb9SZV/pdb
• EM Map EMD-52194: EMDB EMDataResource

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2025-10-15 Released: 2025-12-31 
• Deposition Author(s): Cheng, T.C., Sakata, E., Muntaner, J., Maestro-Lopez, M., Cuellar, J., Valpuesta, J.M.
• Funding Organization(s): German Research Foundation (DFG), Spanish Ministry of Science, Innovation, and Universities

---

Experimental Data Snapshot

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

Literature

Structure of the 26S proteasome in complex with cochaperone Bag1

Maestro-Lopez, M., Cheng, T.C., Muntaner, J., Menedez, M., Alonso, M., Schweitzer, A., Cuellar, J., Valpuesta, J.M., Sakata, E.

To be published.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 47-mer - A2B2C2D2E2F2G2H2I2J2K2L2M2N2O1P1Q1R1S1T1U1V1W1X1Y1Z1a1b1c1d1e1f1g1 Pseudo Symmetry: Asymmetric - C1 
Pseudo Stoichiometry: Hetero 47-mer - A28B6C2D1E1F1G1H1I1J1K1L1M1N1 Local Symmetry: Cyclic - C2  (Explore in 3D)
Local Stoichiometry: Hetero 28-mer - A2B2C2D2E2F2G2H2I2J2K2L2M2N2 

Local Symmetry: Cyclic - C2  (Explore in 3D)
Local Stoichiometry: Hetero 28-mer - A2B2C2D2E2F2G2H2I2J2K2L2M2N2 

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

Biological Assembly Evidence: electron microscopy

Macromolecule Content 

• Total Structure Weight: 1,693.89 kDa 
• Atom Count: 104,040 
• Modeled Residue Count: 13,334 
• Deposited Residue Count: 15,118 
• Unique protein chains: 33

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-6	A [auth G], I [auth g]	246	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P60900 (Homo sapiens) Explore P60900  Go to UniProtKB:  P60900
PHAROS:  P60900 GTEx:  ENSG00000100902

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

Entity ID: 3
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-4	C [auth I], K [auth i]	261	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P25789 (Homo sapiens) Explore P25789  Go to UniProtKB:  P25789
PHAROS:  P25789 GTEx:  ENSG00000041357

Entity ID: 4
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-7	D [auth J], L [auth j]	248	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for O14818 (Homo sapiens) Explore O14818  Go to UniProtKB:  O14818
PHAROS:  O14818 GTEx:  ENSG00000101182

Entity ID: 5
Molecule	Chains	Sequence Length	Organism	Details	Image
Isoform Long of Proteasome subunit alpha type-1	E [auth L], H [auth l]	269	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P25786 (Homo sapiens) Go to UniProtKB:  P25786
PHAROS:  P25786 GTEx:  ENSG00000129084

Entity ID: 6
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-3	F [auth M], N [auth m]	255	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P25788 (Homo sapiens) Explore P25788  Go to UniProtKB:  P25788
PHAROS:  P25788 GTEx:  ENSG00000100567

Entity ID: 7
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit alpha type-5	G [auth K], M [auth k]	241	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P28066 (Homo sapiens) Explore P28066  Go to UniProtKB:  P28066
PHAROS:  P28066 GTEx:  ENSG00000143106

Entity ID: 8
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-6	O [auth n], V [auth N]	239	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P28072 (Homo sapiens) Explore P28072  Go to UniProtKB:  P28072
PHAROS:  P28072 GTEx:  ENSG00000142507

Entity ID: 9
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-7	P [auth o], W [auth O]	277	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for Q99436 (Homo sapiens) Explore Q99436  Go to UniProtKB:  Q99436
PHAROS:  Q99436 GTEx:  ENSG00000136930

Entity ID: 10
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-3	Q [auth p], Y [auth P]	205	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P49720 (Homo sapiens) Explore P49720  Go to UniProtKB:  P49720
PHAROS:  P49720 GTEx:  ENSG00000277791

Entity ID: 11
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-2	R [auth q], X [auth Q]	201	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P49721 (Homo sapiens) Explore P49721  Go to UniProtKB:  P49721
PHAROS:  P49721 GTEx:  ENSG00000126067

Entity ID: 12
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-5	S [auth r], Z [auth R]	263	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P28074 (Homo sapiens) Explore P28074  Go to UniProtKB:  P28074
PHAROS:  P28074 GTEx:  ENSG00000100804

Entity ID: 13
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-1	AA [auth S], T [auth s]	241	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P20618 (Homo sapiens) Explore P20618  Go to UniProtKB:  P20618
PHAROS:  P20618 GTEx:  ENSG00000008018

Entity ID: 14
Molecule	Chains	Sequence Length	Organism	Details	Image
Proteasome subunit beta type-4	BA [auth T], U [auth t]	264	Homo sapiens	Mutation(s): 0  EC: 3.4.25.1
UniProt & NIH Common Fund Data Resources
Find proteins for P28070 (Homo sapiens) Explore P28070  Go to UniProtKB:  P28070
PHAROS:  P28070 GTEx:  ENSG00000159377

Entity ID: 15
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 2	CA [auth f]	908	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for Q13200 (Homo sapiens) Explore Q13200  Go to UniProtKB:  Q13200
PHAROS:  Q13200 GTEx:  ENSG00000175166

Entity ID: 16
Molecule	Chains	Sequence Length	Organism	Details	Image
BAG family molecular chaperone regulator 1	DA [auth x]	230	Homo sapiens	Mutation(s): 0  Gene Names: BAG1, HAP
UniProt & NIH Common Fund Data Resources
Find proteins for Q99933 (Homo sapiens) Explore Q99933  Go to UniProtKB:  Q99933
PHAROS:  Q99933 GTEx:  ENSG00000107262

Entity ID: 17
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 13	EA [auth a]	376	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UNM6 (Homo sapiens) Explore Q9UNM6  Go to UniProtKB:  Q9UNM6
PHAROS:  Q9UNM6 GTEx:  ENSG00000185627

Entity ID: 18
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 4	FA [auth b]	377	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P55036 (Homo sapiens) Explore P55036  Go to UniProtKB:  P55036
PHAROS:  P55036 GTEx:  ENSG00000159352

Entity ID: 19
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 14	GA [auth c]	310	Homo sapiens	Mutation(s): 0  EC: 3.4.19
UniProt & NIH Common Fund Data Resources
Find proteins for O00487 (Homo sapiens) Explore O00487  Go to UniProtKB:  O00487
PHAROS:  O00487 GTEx:  ENSG00000115233

Entity ID: 20
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 8	HA [auth d]	350	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P48556 (Homo sapiens) Explore P48556  Go to UniProtKB:  P48556
PHAROS:  P48556 GTEx:  ENSG00000099341

Entity ID: 21
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome complex subunit SEM1	IA [auth e]	70	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P60896 (Homo sapiens) Explore P60896  Go to UniProtKB:  P60896
PHAROS:  P60896 GTEx:  ENSG00000127922

Entity ID: 22
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 1	JA [auth U]	953	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for Q99460 (Homo sapiens) Explore Q99460  Go to UniProtKB:  Q99460
PHAROS:  Q99460 GTEx:  ENSG00000173692

Entity ID: 23
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 3	KA [auth V]	534	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for O43242 (Homo sapiens) Explore O43242  Go to UniProtKB:  O43242
PHAROS:  O43242 GTEx:  ENSG00000108344

Entity ID: 24
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 11	LA [auth X]	422	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for O00231 (Homo sapiens) Explore O00231  Go to UniProtKB:  O00231
PHAROS:  O00231 GTEx:  ENSG00000108671

Entity ID: 25
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 6	MA [auth Y]	389	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for Q15008 (Homo sapiens) Explore Q15008  Go to UniProtKB:  Q15008
PHAROS:  Q15008 GTEx:  ENSG00000163636

Entity ID: 26
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 7	NA [auth Z]	324	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P51665 (Homo sapiens) Explore P51665  Go to UniProtKB:  P51665
PHAROS:  P51665 GTEx:  ENSG00000103035

Entity ID: 27
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome non-ATPase regulatory subunit 12	OA [auth W]	456	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for O00232 (Homo sapiens) Explore O00232  Go to UniProtKB:  O00232
PHAROS:  O00232 GTEx:  ENSG00000197170

Entity ID: 28
Molecule	Chains	Sequence Length	Organism	Details	Image
26S protease regulatory subunit 7	PA [auth A]	433	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P35998 (Homo sapiens) Explore P35998  Go to UniProtKB:  P35998
PHAROS:  P35998 GTEx:  ENSG00000161057

Entity ID: 29
Molecule	Chains	Sequence Length	Organism	Details	Image
26S protease regulatory subunit 4	QA [auth B]	440	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P62191 (Homo sapiens) Explore P62191  Go to UniProtKB:  P62191
GTEx:  ENSG00000100764

Entity ID: 30
Molecule	Chains	Sequence Length	Organism	Details	Image
Isoform 2 of 26S proteasome regulatory subunit 8	RA [auth C]	398	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P62195 (Homo sapiens) Go to UniProtKB:  P62195
PHAROS:  P62195 GTEx:  ENSG00000087191

Entity ID: 31
Molecule	Chains	Sequence Length	Organism	Details	Image
26S protease regulatory subunit 6B	SA [auth D]	418	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P43686 (Homo sapiens) Explore P43686  Go to UniProtKB:  P43686
PHAROS:  P43686 GTEx:  ENSG00000013275

Entity ID: 32
Molecule	Chains	Sequence Length	Organism	Details	Image
26S proteasome regulatory subunit 10B	TA [auth E]	403	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for A0A087X2I1 (Homo sapiens) Explore A0A087X2I1  Go to UniProtKB:  A0A087X2I1
GTEx:  ENSG00000100519

Entity ID: 33
Molecule	Chains	Sequence Length	Organism	Details	Image
26S protease regulatory subunit 6A	UA [auth F]	439	Homo sapiens	Mutation(s): 0
UniProt & NIH Common Fund Data Resources
Find proteins for P17980 (Homo sapiens) Explore P17980  Go to UniProtKB:  P17980
PHAROS:  P17980 GTEx:  ENSG00000165916

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ATP (Subject of Investigation/LOI)	VA [auth A]	ADENOSINE-5'-TRIPHOSPHATE C10 H16 N5 O13 P3 ZKHQWZAMYRWXGA-KQYNXXCUSA-N
ADP (Subject of Investigation/LOI)	AB [auth F], WA [auth B], XA [auth C], YA [auth D], ZA [auth E]	ADENOSINE-5'-DIPHOSPHATE C10 H15 N5 O10 P2 XTWYTFMLZFPYCI-KQYNXXCUSA-N

Experimental Data & Validation

Experimental Data

• Method: ELECTRON MICROSCOPY
• Resolution: 3.60 Å
• Aggregation State: PARTICLE 
• Reconstruction Method: SINGLE PARTICLE 

EM Software:

Task	Software Package	Version
MODEL REFINEMENT	PHENIX	1.21_5207:
RECONSTRUCTION	cryoSPARC

Structure Validation

Entry History & Funding Information

Deposition Data

• Released Date: 2025-12-31 
Deposition Author(s): Cheng, T.C., Sakata, E., Muntaner, J., Maestro-Lopez, M., Cuellar, J., Valpuesta, J.M.

---

Funding Organization	Location	Grant Number
German Research Foundation (DFG)	Germany	154113120
German Research Foundation (DFG)	Germany	EXC 2067/1-390729940
German Research Foundation (DFG)	Germany	448415290
Spanish Ministry of Science, Innovation, and Universities	Spain	PID2022-137175NB-I00
Spanish Ministry of Science, Innovation, and Universities	Spain	AEI/10.13039/5011000110
Spanish Ministry of Science, Innovation, and Universities	Spain	CEX2023-001386-S

Revision History  

• Version 1.0: 2025-12-31
  Type: Initial release