1FAJ

INORGANIC PYROPHOSPHATASE

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 

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This is version 1.2 of the entry. See complete history. 


Literature

Structure of Escherichia coli inorganic pyrophosphatase at 2.2 A resolution.

Kankare, J., Salminen, T., Lahti, R., Cooperman, B.S., Baykov, A.A., Goldman, A.

(1996) Acta Crystallogr D Biol Crystallogr 52: 551-563

  • DOI: 10.1107/S0907444996000376
  • Primary Citation of Related Structures:  
    1FAJ, 2EIP

  • PubMed Abstract: 

    • The refined crystal structures of hexameric soluble inorganic pyrophosphatase from E. coli (E-PPase) are reported to R factors of 18.7 and 18.3% at 2.15 and 2.2 A, respectively. The first contains one independent monomer; the other, two independent monomers, in an R32 unit cell ...

    The refined crystal structures of hexameric soluble inorganic pyrophosphatase from E. coli (E-PPase) are reported to R factors of 18.7 and 18.3% at 2.15 and 2.2 A, respectively. The first contains one independent monomer; the other, two independent monomers, in an R32 unit cell. Because the E-PPase monomer is small with a large open active site, there are relatively few hydrophobic interactions that connect the active-site loops to the five-stranded twisted beta-barrel that is the hydrophobic core of the molecule. The active-site loops are, however, held in place by interactions between monomers around the threefold and twofold symmetry axes of the D(3) hexamer. Consequently, mutations of active-site residues (such as Glu20 and Lysl04) often affect protein stability and oligomeric structure. Conversely, mutations of residues in the interface between monomers (such as His136 and Hisl40) not only affect oligomeric structure but also affect active-site function. The effects of the H136Q and H140Q variants can be explained by the extended ionic interaction between H140, D143 and H136' of the neighbouring monomer. This interaction is further buttressed by an extensive hydrogen-bonding network that appears to explain why the E-PPase hexamer is so stable and also why the H136Q and H140Q variant proteins are less stable as hexamers.

    Related Citations: 
    • New Crystal Forms of Escherichia Coli and Saccharomyces Cerevisiae Soluble Inorganic Pyrophosphatase
      Heikinheimo, P., Salminen, T., Cooperman, B., Lahti, R., Goldman, A.
      (1995) Acta Crystallogr D Biol Crystallogr 51: 399
    • The Structure of E.Coli Soluble Inorganic Pyrophosphatase at 2.7 A Resolution
      Kankare, J., Neal, G.S., Salminen, T., Glumhoff, T., Cooperman, B.S., Lahti, R., Goldman, A.
      (1994) Protein Eng 7: 823
    Organizational Affiliation: 

    Centre for Biotechnology, Turku, Finland.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
SOLUBLE INORGANIC PYROPHOSPHATASE A175Escherichia coliMutation(s): 0 
EC: 3.6.1.1
Find proteins for P0A7A9 (Escherichia coli (strain K12))
Explore P0A7A9 
Go to UniProtKB:  P0A7A9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.15 Å
  • R-Value Work: 0.187 
  • R-Value Observed: 0.187 
  • Space Group: H 3 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 111.5α = 90
b = 111.5β = 90
c = 76.5γ = 120
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
X-PLORphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1996-11-08
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance