PP1 H66K in complex with Microcystin LR

Experimental Data Snapshot

  • Resolution: 1.84 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.232 

wwPDB Validation   3D Report Full Report

This is version 2.0 of the entry. See complete history


SDS22 selectively recognizes and traps metal-deficient inactive PP1.

Choy, M.S.Moon, T.M.Ravindran, R.Bray, J.A.Robinson, L.C.Archuleta, T.L.Shi, W.Peti, W.Tatchell, K.Page, R.

(2019) Proc Natl Acad Sci U S A 116: 20472-20481

  • DOI: https://doi.org/10.1073/pnas.1908718116
  • Primary Citation of Related Structures:  
    6OBN, 6OBP, 6OBQ, 6OBR, 6OBS, 6OBU

  • PubMed Abstract: 

    The metalloenzyme protein phosphatase 1 (PP1), which is responsible for ≥50% of all dephosphorylation reactions, is regulated by scores of regulatory proteins, including the highly conserved SDS22 protein. SDS22 has numerous diverse functions, surprisingly acting as both a PP1 inhibitor and as an activator. Here, we integrate cellular, biophysical, and crystallographic studies to address this conundrum. We discovered that SDS22 selectively binds a unique conformation of PP1 that contains a single metal (M2) at its active site, i.e., SDS22 traps metal-deficient inactive PP1. Furthermore, we showed that SDS22 dissociation is accompanied by a second metal (M1) being loaded into PP1, as free metal cannot dissociate the complex and M1-deficient mutants remain constitutively trapped by SDS22. Together, our findings reveal that M1 metal loading and loss are essential for PP1 regulation in cells, which has broad implications for PP1 maturation, activity, and holoenzyme subunit exchange.

  • Organizational Affiliation

    Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721.

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): 1 
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

Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Microcystin LR
C, D
7Microcystis aeruginosaMutation(s): 0 
Sequence Annotations
  • Reference Sequence
Biologically Interesting Molecules (External Reference) 1 Unique
Experimental Data & Validation

Experimental Data

  • Resolution: 1.84 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.230 
  • R-Value Observed: 0.232 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 64.916α = 90
b = 76.619β = 90
c = 130.927γ = 90
Software Package:
Software NamePurpose
PROTEUM PLUSdata reduction
PROTEUM PLUSdata scaling

Structure Validation

View Full Validation Report

Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
National Institutes of Health/National Human Genome Research Institute (NIH/NHGRI)United States--

Revision History  (Full details and data files)

  • Version 1.0: 2019-09-18
    Type: Initial release
  • Version 1.1: 2019-09-25
    Changes: Data collection, Database references
  • Version 1.2: 2019-10-02
    Changes: Data collection, Database references
  • Version 1.3: 2019-10-23
    Changes: Data collection, Database references
  • Version 1.4: 2019-12-18
    Changes: Author supporting evidence
  • Version 1.5: 2023-10-11
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 2.0: 2023-11-15
    Changes: Atomic model, Data collection, Derived calculations