2BE7

Crystal structure of the unliganded (T-state) aspartate transcarbamoylase of the psychrophilic bacterium Moritella profunda


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.214 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural investigation of cold activity and regulation of aspartate carbamoyltransferase from the extreme psychrophilic bacterium Moritella profunda.

De Vos, D.Xu, Y.Hulpiau, P.Vergauwen, B.Van Beeumen, J.J.

(2007) J Mol Biol 365: 379-395

  • DOI: 10.1016/j.jmb.2006.09.064
  • Primary Citation of Related Structures:  
    2BE7

  • PubMed Abstract: 
  • Aspartate carbamoyltransferase (EC 2.1.3.2) is extensively studied as a model for cooperativity and allosteric regulation. The structure of the Escherichia coli enzyme has been thoroughly analyzed by X-ray crystallography, and recently the crystal structures of two hyperthermophilic ATCases of the same structural class have been characterized ...

    Aspartate carbamoyltransferase (EC 2.1.3.2) is extensively studied as a model for cooperativity and allosteric regulation. The structure of the Escherichia coli enzyme has been thoroughly analyzed by X-ray crystallography, and recently the crystal structures of two hyperthermophilic ATCases of the same structural class have been characterized. We here report the detailed functional and structural investigation of the ATCase from the psychrophilic deep sea bacterium Moritella profunda. Our analysis indicates that the enzyme conforms to the E. coli model in that two allosteric states exist that are influenced by similar homotropic interactions. The heterotropic properties differ in that CTP and UTP inhibit the holoenzyme, but ATP seems to exhibit a dual regulatory pattern, activating the enzyme at low concentrations and inhibiting it in the mM range. The crystal structure of the unliganded M. profunda ATCase shows resemblance to a more extreme T state reported previously for an E. coli ATCase mutant. A detailed molecular analysis reveals potential features of adaptation to cold activity and cold regulation. Moreover, M. profunda ATCase presents similarities with certain mutants of E. coli ATCase altered in their kinetic properties or temperature relationships. Finally, structural and functional comparison of ATCases across the full physiological temperature range agrees with an important, but fundamentally different role for electrostatics in protein adaptation at both extremes, i.e. an increased stability through the formation of ion pairs and ion pair networks at high physiological temperatures, and an increased flexibility through enhanced protein solvation at low temperatures.


    Related Citations: 
    • Expression, purification, crystallization and preliminary X-ray crystallographic studies of a cold-adapted aspartate carbamoyltransferase from Moritella profunda.
      De Vos, D., Hulpiau, P., Vergauwen, B., Savvides, S.N., Van Beeumen, J.
      (2005) Acta Crystallogr Sect F Struct Biol Cryst Commun 61: 279

    Organizational Affiliation

    Laboratory of Protein Biochemistry and Protein Engineering, Ghent University, K.L. Ledeganckstraat 35, 9000 Gent, Belgium.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Aspartate Carbamoyltransferase Catalytic Chain ABC326Moritella profundaMutation(s): 0 
Gene Names: pyrB
EC: 2.1.3.2
Find proteins for D0VWV8 (Moritella profunda)
Explore D0VWV8 
Go to UniProtKB:  D0VWV8
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Aspartate Carbamoyltransferase Regulatory Chain DEF153Moritella profundaMutation(s): 0 
Gene Names: pyrI
Find proteins for D0VWV9 (Moritella profunda)
Explore D0VWV9 
Go to UniProtKB:  D0VWV9
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.85 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.212 
  • R-Value Observed: 0.214 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 129.238α = 90
b = 129.238β = 90
c = 207.232γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-10-31
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance
  • Version 1.3: 2017-12-20
    Changes: Database references