Crystal structure of the 2H-phosphatase domain of Sts-2

Experimental Data Snapshot

  • Resolution: 1.95 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.210 

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Structural and functional characterization of the 2H-phosphatase domain of Sts-2 reveals an acid-dependent phosphatase activity.

Chen, Y.Jakoncic, J.Carpino, N.Nassar, N.

(2009) Biochemistry 48: 1681-1690

  • DOI: https://doi.org/10.1021/bi802219n
  • Primary Citation of Related Structures:  
    3D4I, 3D6A, 3DB1

  • PubMed Abstract: 

    The suppressors of T cell receptor (TCR) signaling 1 and 2 (Sts-1 and -2, respectively) are multidomain proteins that negatively regulate the signaling of membrane-bound receptors, including TCR and the epidermal growth factor receptor (EGFR). Sts-1 was recently shown to be a new type of protein tyrosine phosphatase (PTP), with the phosphatase activity located within its C-terminal phosphoglycerate mutase (PGM) homology domain and key for the regulation of TCR signaling in T cells. The activity of the related Sts-2 enzyme is significantly less than that of Sts-1. Here we investigate the phosphatase activity of the PGM domain of Sts-2, Sts-2(PGM). The crystal structure of Sts-2(PGM) is remarkably similar to Sts-1(PGM), including conservation of all catalytic residues. Insight into mechanistic details is provided by the structures of the apo, tungstate-bound, and phosphate-bound enzyme. The active site shows stringent specificity, with the k(cat) optimum at pH 5.0 suggesting that Sts-2 might function as an acid-dependent phosphatase. Mutation of active site residues Gln372, Ala446, Glu481, Ser552, and Ser582 to their equivalents in Sts-1 increases the phosphatase activity of Sts-2(PGM) toward model substrates. Overall, our data demonstrate that Sts-2(PGM) adopts the conformation of an active phosphatase whose activity is fundamentally different from that of Sts-1 despite the strong structural homology. They also demonstrate that nonconserved active site residues are responsible for the difference in activity between the two isoforms. These differences reflect possible distinct physiological substrates.

  • Organizational Affiliation

    Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York 11794-8661, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Sts-2 protein
A, B, C, D
273Mus musculusMutation(s): 0 
Gene Names: Ubash3a
UniProt & NIH Common Fund Data Resources
Find proteins for Q3V3E1 (Mus musculus)
Explore Q3V3E1 
Go to UniProtKB:  Q3V3E1
IMPC:  MGI:1926074
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ3V3E1
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on CL

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 1.95 Å
  • R-Value Free: 0.248 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.210 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 77.887α = 90
b = 115.707β = 90
c = 121.222γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-03-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance