1TUG

Aspartate Transcarbamoylase Catalytic Chain Mutant E50A Complex with Phosphonoacetamide, Malonate, and Cytidine-5-Prime-Triphosphate (CTP)


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.272 
  • R-Value Observed: 0.220 

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This is version 1.3 of the entry. See complete history


Literature

Monitoring the Transition from the T to the R State in E.coli Aspartate Transcarbamoylase by X-ray Crystallography: Crystal Structures of the E50A Mutant Enzyme in Four Distinct Allosteric States.

Stieglitz, K.Stec, B.Baker, D.P.Kantrowitz, E.R.

(2004) J Mol Biol 341: 853-868

  • DOI: 10.1016/j.jmb.2004.06.002
  • Primary Citation of Related Structures:  
    1TTH, 1TU0, 1TUG

  • PubMed Abstract: 
  • A detailed description of the transition that allosteric enzymes undergo constitutes a major challenge in structural biology. We have succeeded in trapping four distinct allosteric states of a mutant enzyme of Escherichia coli aspartate transcarbomylase and determining their structures by X-ray crystallography ...

    A detailed description of the transition that allosteric enzymes undergo constitutes a major challenge in structural biology. We have succeeded in trapping four distinct allosteric states of a mutant enzyme of Escherichia coli aspartate transcarbomylase and determining their structures by X-ray crystallography. The mutant version of aspartate transcarbamoylase in which Glu50 in the catalytic chains was replaced by Ala destabilizes the native R state and shifts the equilibrium towards the T state. This behavior allowed the use of substrate analogs such as phosphonoacetamide and malonate to trap the enzyme in T-like and R-like structures that are distinct from the T-state structure of the wild-type enzyme (as represented by the structure of the enzyme with CTP bound and the R-state structure as represented by the structure with N-(phosphonacetyl)-L-aspartate bound). These structures shed light on the nature and the order of internal structural rearrangements during the transition from the T to the R state. They also suggest an explanation for diminished activity of the E50A enzyme and for the change in reaction mechanism from ordered to random for this mutant enzyme.


    Organizational Affiliation

    Department of Chemistry, Merkert Chemistry Center, Boston College, Chestnut Hill, MA 02467, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Aspartate carbamoyltransferase catalytic chainA, C310Escherichia coliMutation(s): 1 
Gene Names: pyrBb4245C5345Z5856ECS5222SF4245S4507
EC: 2.1.3.2
UniProt
Find proteins for P0A786 (Escherichia coli (strain K12))
Explore P0A786 
Go to UniProtKB:  P0A786
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 chainB, D153Escherichia coliMutation(s): 0 
Gene Names: pyrIb4244C5344Z5855ECS5221
UniProt
Find proteins for P0A7F3 (Escherichia coli (strain K12))
Explore P0A7F3 
Go to UniProtKB:  P0A7F3
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.272 
  • R-Value Observed: 0.220 
  • Space Group: P 3 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 122.29α = 90
b = 122.29β = 90
c = 142.41γ = 120
Software Package:
Software NamePurpose
SHELXmodel building
SHELXL-97refinement
SDMSdata reduction
SDMSdata scaling
X-PLORphasing

Structure Validation

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Ligand Structure Quality Assessment  



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2004-07-20
    Type: Initial release
  • Version 1.1: 2008-04-30
    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