1PA1

Crystal structure of the C215D mutant of protein tyrosine phosphatase 1B


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.190 

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This is version 1.3 of the entry. See complete history


Literature

Functional characterization and crystal structure of the C215D mutant of protein-tyrosine phosphatase-1B

Romsicki, Y.Scapin, G.Beaulieu-Audy, V.Patel, S.Becker, J.W.Kennedy, B.P.Asante-Appiah, E.

(2003) J Biol Chem 278: 29009-29015

  • DOI: 10.1074/jbc.M303817200
  • Primary Citation of Related Structures:  
    1PA1

  • PubMed Abstract: 
  • We have characterized the C215D active-site mutant of protein-tyrosine phosphatase-1B (PTP-1B) and solved the crystal structure of the catalytic domain of the apoenzyme to a resolution of 1.6 A. The mutant enzyme displayed maximal catalytic activity at pH approximately 4 ...

    We have characterized the C215D active-site mutant of protein-tyrosine phosphatase-1B (PTP-1B) and solved the crystal structure of the catalytic domain of the apoenzyme to a resolution of 1.6 A. The mutant enzyme displayed maximal catalytic activity at pH approximately 4.5, which is significantly lower than the pH optimum of 6 for wild-type PTP-1B. Although both forms of the enzyme exhibited identical Km values for hydrolysis of p-nitrophenyl phosphate at pH 4.5 and 6, the kcat values of C215D were approximately 70- and approximately 7000-fold lower than those of wild-type PTP-1B, respectively. Arrhenius plots revealed that the mutant and wild-type enzymes displayed activation energies of 61 +/- 1 and 18 +/- 2 kJ/mol, respectively, at their pH optima. Unlike wild-type PTP-1B, C215D-mediated p-nitrophenyl phosphate hydrolysis was inactivated by 1,2-epoxy-3-(p-nitrophenoxy)propane, suggesting a direct involvement of Asp215 in catalysis. Increasing solvent microviscosity with sucrose (up to 40% (w/v)) caused a significant decrease in kcat/Km of the wild-type enzyme, but did not alter the catalytic efficiency of the mutant protein. Structurally, the apoenzyme was identical to wild-type PTP-1B, aside from the flexible WPD loop region, which was in both "open" and "closed" conformations. At physiological pH, the C215D mutant of PTP-1B should be an effective substrate-trapping mutant that can be used to identify cellular substrates of PTP-1B. In addition, because of its insensitivity to oxidation, this mutant may be used for screening fermentation broth and other natural products to identify inhibitors of PTP-1B.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Merck Frosst Centre for Therapeutic Research, Pointe-Claire, Dorval, Quebec H9R 4P8, Canada.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Protein-tyrosine phosphatase, non-receptor type 1A310Homo sapiensMutation(s): 1 
Gene Names: PTPN1PTP1B
EC: 3.1.3.48
UniProt & NIH Common Fund Data Resources
Find proteins for P18031 (Homo sapiens)
Explore P18031 
Go to UniProtKB:  P18031
PHAROS:  P18031
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP18031
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Free: 0.204 
  • R-Value Work: 0.186 
  • R-Value Observed: 0.190 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 88.451α = 90
b = 88.451β = 90
c = 104.356γ = 120
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling
CNXrefinement
CCP4data scaling
CNXphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2003-08-05
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2021-10-27
    Changes: Database references, Derived calculations