1XGE

Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between subunits


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 

Starting Model: experimental
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This is version 1.5 of the entry. See complete history


Literature

Dihydroorotase from Escherichia coli: Loop Movement and Cooperativity between Subunits

Lee, M.Chan, C.W.Guss, J.M.Christopherson, R.I.Maher, M.J.

(2005) J Mol Biol 348: 523-533

  • DOI: https://doi.org/10.1016/j.jmb.2005.01.067
  • Primary Citation of Related Structures:  
    1XGE

  • PubMed Abstract: 

    Escherichia coli dihydroorotase has been crystallized in the presence of the product, L-dihydroorotate (L-DHO), and the structure refined at 1.9A resolution. The structure confirms that previously reported (PDB entry 1J79), crystallized in the presence of the substrate N-carbamyl-D,L-aspartate (D, L-CA-asp), which had a dimer in the asymmetric unit, with one subunit having the substrate, L-CA-asp bound at the active site and the other having L-DHO. Importantly, no explanation for the unusual structure was given. Our results now show that a loop comprised of residues 105-115 has different conformations in the two subunits. In the case of the L-CA-asp-bound subunit, this loop reaches in toward the active site and makes hydrogen-bonding contact with the bound substrate molecule. For the L-DHO-bound subunit, the loop faces in the opposite direction and forms part of the surface of the protein. Analysis of the kinetics for conversion of L-DHO to L-CA-asp at low concentrations of L-DHO shows positive cooperativity with a Hill coefficient n=1.57(+/-0.13). Communication between subunits in the dimer may occur via cooperative conformational changes of the side-chains of a tripeptide from each subunit: Arg256-His257-Arg258, near the subunit interface.


  • Organizational Affiliation

    School of Molecular and Microbial Biosciences, University of Sydney, Sydney, New South Wales 2006, Australia.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Dihydroorotase
A, B
347Escherichia coliMutation(s): 1 
Gene Names: pyrC
EC: 3.5.2.3
UniProt
Find proteins for P05020 (Escherichia coli (strain K12))
Explore P05020 
Go to UniProtKB:  P05020
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP05020
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
KCX
Query on KCX
A, B
L-PEPTIDE LINKINGC7 H14 N2 O4LYS
Binding Affinity Annotations 
IDSourceBinding Affinity
DOR PDBBind:  1XGE Kd: 2.08e+4 (nM) from 1 assay(s)
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.90 Å
  • R-Value Free: 0.211 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.582α = 90
b = 78.826β = 90
c = 180.222γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-04-26
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2017-10-11
    Changes: Refinement description
  • Version 1.4: 2023-10-25
    Changes: Data collection, Database references, Derived calculations, Refinement description
  • Version 1.5: 2023-11-15
    Changes: Data collection