Biological Assembly 1  

 3D View: Structure | Electron Density

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Hetero 2-mer - A1B1 

Biological assembly 1 assigned by authors.

Macromolecule Content

• Total Structure Weight: 43.82 kDa 
• Atom Count: 2708 
• Modelled Residue Count: 324 
• Deposited Residue Count: 373 
• Unique protein chains: 2

4IYP

structure of the nPP2Ac-alpha4 complex

• DOI: 10.2210/pdb4IYP/pdb

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


• Deposited: 2013-01-29 Released: 2013-04-17 
• Deposition Author(s): Jiang, L., Stanevich, V., Satyshur, K.A., Xing, Y.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.222 
• R-Value Work: 0.179 
• R-Value Observed: 0.181 

Literature

Structural basis of protein phosphatase 2A stable latency.

Jiang, L., Stanevich, V., Satyshur, K.A., Kong, M., Watkins, G.R., Wadzinski, B.E., Sengupta, R., Xing, Y.

(2013) Nat Commun 4: 1699-1699

• PubMed: 23591866 
• DOI: 10.1038/ncomms2663
• Primary Citation of Related Structures:  
  4IYP


• PubMed Abstract: 
  

The catalytic subunit of protein phosphatase 2A (PP2Ac) is stabilized in a latent form by α4, a regulatory protein essential for cell survival and biogenesis of all PP2A complexes. Here we report the structure of α4 bound to the N-terminal fragment of PP2Ac. This structure suggests that α4 binding to the full-length PP2Ac requires local unfolding near the active site, which perturbs the scaffold subunit binding site at the opposite surface via allosteric relay. These changes stabilize an inactive conformation of PP2Ac and convert oligomeric PP2A complexes to the α4 complex upon perturbation of the active site. The PP2Ac-α4 interface is essential for cell survival and sterically hinders a PP2A ubiquitination site, important for the stability of cellular PP2Ac. Our results show that α4 is a scavenger chaperone that binds to and stabilizes partially folded PP2Ac for stable latency, and reveal a mechanism by which α4 regulates cell survival, and biogenesis and surveillance of PP2A holoenzymes.

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Organizational Affiliation: 

McArdle Laboratory, Department of Oncology, University of Wisconsin-Madison, School of Medicine and Public Health, Madison, Wisconsin 53706, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Immunoglobulin-binding protein 1	A	222	Homo sapiens	Mutation(s): 0  Gene Names: alpha4, IBP1, IGBP1
UniProt & NIH Common Fund Data Resources
Find proteins for P78318 (Homo sapiens) Explore P78318  Go to UniProtKB:  P78318
PHAROS:  P78318 GTEx:  ENSG00000089289

Entity ID: 2
Molecule	Chains	Sequence Length	Organism	Details	Image
Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform	B [auth C]	151	Homo sapiens	Mutation(s): 0  Gene Names: PP2Ac, ppp2c, PPP2CA EC: 3.1.3.16
UniProt & NIH Common Fund Data Resources
Find proteins for P67775 (Homo sapiens) Explore P67775  Go to UniProtKB:  P67775
PHAROS:  P67775 GTEx:  ENSG00000113575

Small Molecules

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
MSE	A	L-PEPTIDE LINKING	C5 H11 N O2 Se		MET

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.80 Å
• R-Value Free: 0.222 
• R-Value Work: 0.179 
• R-Value Observed: 0.181 
• Space Group: P 3₂ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 116.127	α = 90
b = 116.127	β = 90
c = 81.23	γ = 120

Software Package:

Software Name	Purpose
ADSC	data collection
CRANK	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-01-29 
• Released Date: 2013-04-17 
Deposition Author(s): Jiang, L., Stanevich, V., Satyshur, K.A., Xing, Y.

Revision History  

• Version 1.0: 2013-04-17
  Type: Initial release
  
• Version 1.1: 2013-05-29
  Changes: Database references
• Version 1.2: 2017-11-15
  Changes: Refinement description