1.45 A Resolution Crystal Structure of Protein Phosphatase 1

Experimental Data Snapshot

  • Resolution: 1.45 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.151 

wwPDB Validation   3D Report Full Report

This is version 1.3 of the entry. See complete history


Understanding the antagonism of retinoblastoma protein dephosphorylation by PNUTS provides insights into the PP1 regulatory code.

Choy, M.S.Hieke, M.Kumar, G.S.Lewis, G.R.Gonzalez-Dewhitt, K.R.Kessler, R.P.Stein, B.J.Hessenberger, M.Nairn, A.C.Peti, W.Page, R.

(2014) Proc Natl Acad Sci U S A 111: 4097-4102

  • DOI: https://doi.org/10.1073/pnas.1317395111
  • Primary Citation of Related Structures:  
    4MOV, 4MOY, 4MP0

  • PubMed Abstract: 

    The serine/threonine protein phosphatase 1 (PP1) dephosphorylates hundreds of key biological targets by associating with nearly 200 regulatory proteins to form highly specific holoenzymes. However, how these proteins direct PP1 specificity and the ability to predict how these PP1 interacting proteins bind PP1 from sequence alone is still missing. PP1 nuclear targeting subunit (PNUTS) is a PP1 targeting protein that, with PP1, plays a central role in the nucleus, where it regulates chromatin decondensation, RNA processing, and the phosphorylation state of fundamental cell cycle proteins, including the retinoblastoma protein (Rb), p53, and MDM2. The molecular function of PNUTS in these processes is completely unknown. Here, we show that PNUTS, which is intrinsically disordered in its free form, interacts strongly with PP1 in a highly extended manner. Unexpectedly, PNUTS blocks one of PP1's substrate binding grooves while leaving the active site accessible. This interaction site, which we have named the arginine site, allowed us to define unique PP1 binding motifs, which advances our ability to predict how more than a quarter of the known PP1 regulators bind PP1. Additionally, the structure shows how PNUTS inhibits the PP1-mediated dephosphorylation of critical substrates, especially Rb, by blocking their binding sites on PP1, insights that are providing strategies for selectively enhancing Rb activity.

  • Organizational Affiliation

    Departments of Molecular Pharmacology, Physiology, and Biotechnology, Molecular Biology, Cell Biology, and Biochemistry, and Chemistry, Brown University, Providence, RI 02912.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein phosphatase PP1-alpha catalytic subunit
A, B
299Homo sapiensMutation(s): 0 
Gene Names: PPP1CAPPP1A
UniProt & NIH Common Fund Data Resources
Find proteins for P62136 (Homo sapiens)
Explore P62136 
Go to UniProtKB:  P62136
PHAROS:  P62136
GTEx:  ENSG00000172531 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP62136
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.45 Å
  • R-Value Free: 0.167 
  • R-Value Work: 0.150 
  • R-Value Observed: 0.151 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 65.724α = 90
b = 77.6β = 90
c = 133.035γ = 90
Software Package:
Software NamePurpose
SCALAdata scaling
PDB_EXTRACTdata extraction
CBASSdata collection
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2014-03-26
    Type: Initial release
  • Version 1.1: 2014-04-23
    Changes: Database references
  • Version 1.2: 2017-11-15
    Changes: Refinement description
  • Version 1.3: 2023-09-20
    Changes: Data collection, Database references, Derived calculations, Refinement description