Biological Assembly 1  

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Global Symmetry: Dihedral - D3  (3D View)
Global Stoichiometry: Homo 6-mer - A6 

Biological assembly 1 assigned by authors and generated by PISA,PQS (software)

Macromolecule Content

• Total Structure Weight: 19597.33 
• Atom Count: 1327 
• Residue Count: 175 
• Unique protein chains: 1

1FAJ

INORGANIC PYROPHOSPHATASE

• DOI: 10.2210/pdb1FAJ/pdb

• Classification: INORGANIC PYROPHOSPHATASE
• Organism(s): Escherichia coli (strain K12)


• Deposited: 1996-01-10 Released: 1996-11-08 
• Deposition Author(s): Kankare, J.A., Salminen, T., Goldman, A.

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Experimental Data Snapshot

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

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.,Sect.D 52: 551-563

• PubMed: 15299678 
• DOI: 10.1107/S0907444996000376
• Primary Citation of Related Structures:  
  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. 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.

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Related Citations: 

• 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
• 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.,Sect.D 51: 399




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Organizational Affiliation: 

Centre for Biotechnology, Turku, Finland.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
SOLUBLE INORGANIC PYROPHOSPHATASE	A	175	Escherichia coli (strain K12)	Mutation(s): 0  Gene Names: ppa EC: 3.6.1.1
Find proteins for P0A7A9 (Escherichia coli (strain K12)) Go to UniProtKB:  P0A7A9

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.15 Å
• R-Value Work: 0.187 
• Space Group: H 3 2

Unit Cell:

Length (Å)	Angle (°)
a = 111.500	α = 90.00
b = 111.500	β = 90.00
c = 76.500	γ = 120.00

Software Package:

Software Name	Purpose
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing
DENZO	data reduction

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1996-01-10 
• Released Date: 1996-11-08 
• Deposition Author(s): Kankare, J.A., Salminen, T., Goldman, A.

Revision History 

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