3TYP

The crystal structure of the inorganic triphosphatase NE1496


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.215 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

A specific inorganic triphosphatase from Nitrosomonas europaea: structure and catalytic mechanism.

Delvaux, D.Murty, M.R.V.S.Gabelica, V.Lakaye, B.Lunin, V.V.Skarina, T.Onopriyenko, O.Kohn, G.Wins, P.De Pauw, E.Bettendorff, L.

(2011) J Biol Chem 286: 34023-34035

  • DOI: 10.1074/jbc.M111.233585
  • Primary Citation of Related Structures:  
    3TYP

  • PubMed Abstract: 
  • The CYTH superfamily of proteins is named after its two founding members, the CyaB adenylyl cyclase from Aeromonas hydrophila and the human 25-kDa thiamine triphosphatase. Because these proteins often form a closed β-barrel, they are also referred to as triphosphate tunnel metalloenzymes (TTM) ...

    The CYTH superfamily of proteins is named after its two founding members, the CyaB adenylyl cyclase from Aeromonas hydrophila and the human 25-kDa thiamine triphosphatase. Because these proteins often form a closed β-barrel, they are also referred to as triphosphate tunnel metalloenzymes (TTM). Functionally, they are characterized by their ability to bind triphosphorylated substrates and divalent metal ions. These proteins exist in most organisms and catalyze different reactions depending on their origin. Here we investigate structural and catalytic properties of the recombinant TTM protein from Nitrosomonas europaea (NeuTTM), a 19-kDa protein. Crystallographic data show that it crystallizes as a dimer and that, in contrast to other TTM proteins, it has an open β-barrel structure. We demonstrate that NeuTTM is a highly specific inorganic triphosphatase, hydrolyzing tripolyphosphate (PPP(i)) with high catalytic efficiency in the presence of Mg(2+). These data are supported by native mass spectrometry analysis showing that the enzyme binds PPP(i) (and Mg-PPP(i)) with high affinity (K(d) < 1.5 μm), whereas it has a low affinity for ATP or thiamine triphosphate. In contrast to Aeromonas and Yersinia CyaB proteins, NeuTTM has no adenylyl cyclase activity, but it shares several properties with other enzymes of the CYTH superfamily, e.g. heat stability, alkaline pH optimum, and inhibition by Ca(2+) and Zn(2+) ions. We suggest a catalytic mechanism involving a catalytic dyad formed by Lys-52 and Tyr-28. The present data provide the first characterization of a new type of phosphohydrolase (unrelated to pyrophosphatases or exopolyphosphatases), able to hydrolyze inorganic triphosphate with high specificity.


    Organizational Affiliation

    GIGA-Neuroscience, University of Liège, B-4000 Liège, Belgium.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Uncharacterized protein AB155Nitrosomonas europaeaMutation(s): 0 
Gene Names: NE1496
EC: 3.6.1.25
Find proteins for Q82UI9 (Nitrosomonas europaea (strain ATCC 19718 / CIP 103999 / KCTC 2705 / NBRC 14298))
Explore Q82UI9 
Go to UniProtKB:  Q82UI9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.213 
  • R-Value Observed: 0.215 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.282α = 90
b = 52.282β = 90
c = 252.484γ = 120
Software Package:
Software NamePurpose
REFMACrefinement

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-05-09
    Type: Initial release
  • Version 1.1: 2012-08-01
    Changes: Structure summary