Structure of PP1-Phactr1 chimera [PP1(7-304) + linker (SGSGS) + Phactr1(526-580)]

Experimental Data Snapshot

  • Resolution: 1.78 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.242 
  • R-Value Observed: 0.243 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Molecular basis for substrate specificity of the Phactr1/PP1 phosphatase holoenzyme.

Fedoryshchak, R.O.Prechova, M.Butler, A.Lee, R.O'Reilly, N.Flynn, H.R.Snijders, A.P.Eder, N.Ultanir, S.Mouilleron, S.Treisman, R.

(2020) Elife 9

  • DOI: https://doi.org/10.7554/eLife.61509
  • Primary Citation of Related Structures:  
    6ZEE, 6ZEF, 6ZEG, 6ZEH, 6ZEI, 6ZEJ

  • PubMed Abstract: 

    PPP-family phosphatases such as PP1 have little intrinsic specificity. Cofactors can target PP1 to substrates or subcellular locations, but it remains unclear how they might confer sequence-specificity on PP1. The cytoskeletal regulator Phactr1 is a neuronally enriched PP1 cofactor that is controlled by G-actin. Structural analysis showed that Phactr1 binding remodels PP1's hydrophobic groove, creating a new composite surface adjacent to the catalytic site. Using phosphoproteomics, we identified mouse fibroblast and neuronal Phactr1/PP1 substrates, which include cytoskeletal components and regulators. We determined high-resolution structures of Phactr1/PP1 bound to the dephosphorylated forms of its substrates IRSp53 and spectrin αII. Inversion of the phosphate in these holoenzyme-product complexes supports the proposed PPP-family catalytic mechanism. Substrate sequences C-terminal to the dephosphorylation site make intimate contacts with the composite Phactr1/PP1 surface, which are required for efficient dephosphorylation. Sequence specificity explains why Phactr1/PP1 exhibits orders-of-magnitude enhanced reactivity towards its substrates, compared to apo-PP1 or other PP1 holoenzymes.

  • Organizational Affiliation

    Signalling and Transcription Laboratory, The Francis Crick Institute, London, United Kingdom.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Serine/threonine-protein phosphatase PP1-alpha catalytic subunit,Phosphatase and actin regulator363Homo sapiensMutation(s): 0 
Gene Names: PPP1CAPPP1APHACTR1hCG_1818446
UniProt & NIH Common Fund Data Resources
Find proteins for Q9C0D0 (Homo sapiens)
Explore Q9C0D0 
Go to UniProtKB:  Q9C0D0
GTEx:  ENSG00000112137 
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 GroupsQ9C0D0P62136
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on GOL

Download Ideal Coordinates CCD File 
I [auth A]
J [auth A]
N [auth F]
Q [auth I]
V [auth O]
I [auth A],
J [auth A],
N [auth F],
Q [auth I],
V [auth O],
W [auth O],
X [auth O]
C3 H8 O3
Query on EDO

Download Ideal Coordinates CCD File 
K [auth A]1,2-ETHANEDIOL
C2 H6 O2
Query on MN

Download Ideal Coordinates CCD File 
G [auth D]
H [auth D]
L [auth A]
M [auth A]
O [auth F]
G [auth D],
H [auth D],
L [auth A],
M [auth A],
O [auth F],
P [auth F],
R [auth I],
S [auth I],
T [auth L],
U [auth L],
Y [auth O],
Z [auth O]
Experimental Data & Validation

Experimental Data

  • Resolution: 1.78 Å
  • R-Value Free: 0.271 
  • R-Value Work: 0.242 
  • R-Value Observed: 0.243 
  • Space Group: P 65
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 137.37α = 90
b = 137.37β = 90
c = 238.02γ = 120
Software Package:
Software NamePurpose
xia2data reduction
Aimlessdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2020-09-30
    Type: Initial release
  • Version 1.1: 2020-10-07
    Changes: Database references
  • Version 1.2: 2024-01-24
    Changes: Data collection, Database references, Refinement description