6JPT

Crystal structure of human PAC3 homodimer (trigonal form)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.96 Å
  • R-Value Free: 0.146 
  • R-Value Work: 0.136 
  • R-Value Observed: 0.136 

wwPDB Validation   3D Report Full Report


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Literature

Molecular and Structural Basis of the Proteasome alpha Subunit Assembly Mechanism Mediated by the Proteasome-Assembling Chaperone PAC3-PAC4 Heterodimer.

Satoh, T.Yagi-Utsumi, M.Okamoto, K.Kurimoto, E.Tanaka, K.Kato, K.

(2019) Int J Mol Sci 20

  • DOI: 10.3390/ijms20092231
  • Primary Citation of Related Structures:  
    6JPT

  • PubMed Abstract: 
  • The 26S proteasome is critical for the selective degradation of proteins in eukaryotic cells. This enzyme complex is composed of approximately 70 subunits, including the structurally homologous proteins α1-α7, which combine to form heptameric rings. The correct arrangement of these α subunits is essential for the function of the proteasome, but their assembly does not occur autonomously ...

    The 26S proteasome is critical for the selective degradation of proteins in eukaryotic cells. This enzyme complex is composed of approximately 70 subunits, including the structurally homologous proteins α1-α7, which combine to form heptameric rings. The correct arrangement of these α subunits is essential for the function of the proteasome, but their assembly does not occur autonomously. Assembly of the α subunit is assisted by several chaperones, including the PAC3-PAC4 heterodimer. In this study we showed that the PAC3-PAC4 heterodimer functions as a molecular matchmaker, stabilizing the α4-α5-α6 subcomplex during the assembly of the α-ring. We solved a 0.96-Å atomic resolution crystal structure for a PAC3 homodimer which, in conjunction with nuclear magnetic resonance (NMR) data, highlighted the mobility of the loop comprised of residues 51 to 61. Based on these structural and dynamic data, we created a three-dimensional model of the PAC3-4/α4/α5/α6 quintet complex, and used this model to investigate the molecular and structural basis of the mechanism of proteasome α subunit assembly, as mediated by the PAC3-PAC4 heterodimeric chaperone. Our results provide a potential basis for the development of selective inhibitors against proteasome biogenesis.


    Organizational Affiliation

    Institute for Molecular Science, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan. kkatonmr@ims.ac.jp.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Proteasome assembly chaperone 3A122Homo sapiensMutation(s): 0 
Gene Names: PSMG3C7orf48PAC3
UniProt & NIH Common Fund Data Resources
Find proteins for Q9BT73 (Homo sapiens)
Explore Q9BT73 
Go to UniProtKB:  Q9BT73
PHAROS:  Q9BT73
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9BT73
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SCN
Query on SCN

Download Ideal Coordinates CCD File 
B [auth A]THIOCYANATE ION
C N S
ZMZDMBWJUHKJPS-UHFFFAOYSA-M
 Ligand Interaction
K
Query on K

Download Ideal Coordinates CCD File 
C [auth A]POTASSIUM ION
K
NPYPAHLBTDXSSS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 0.96 Å
  • R-Value Free: 0.146 
  • R-Value Work: 0.136 
  • R-Value Observed: 0.136 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.229α = 90
b = 71.229β = 90
c = 47.074γ = 120
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
Aimlessdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Ministry of Education, Culture, Sports, Science and Technology (Japan)JapanJP26460051, JP25102008, JP15H02491

Revision History  (Full details and data files)

  • Version 1.0: 2019-05-29
    Type: Initial release