2EG6

The crystal structure of the ligand-free dihydroorotase from E. coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.174 
  • R-Value Observed: 0.176 

wwPDB Validation   3D Report Full Report


This is version 1.5 of the entry. See complete history


Literature

Structures of Ligand-free and Inhibitor Complexes of Dihydroorotase from Escherichia coli: Implications for Loop Movement in Inhibitor Design

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

(2007) J Mol Biol 370: 812-825

  • DOI: https://doi.org/10.1016/j.jmb.2007.05.019
  • Primary Citation of Related Structures:  
    2EG6, 2EG7, 2EG8

  • PubMed Abstract: 

    Dihydroorotase (DHOase) catalyzes the reversible cyclization of N-carbamyl-L-aspartate (CA-asp) to L-dihydroorotate (DHO) in the de novo biosynthesis of pyrimidine nucleotides. DHOase is a potential anti-malarial drug target as malarial parasites can only synthesize pyrimidines via the de novo pathway and do not possess a salvage pathway. Here we report the structures of Escherichia coli DHOase crystallized without ligand (1.7 A resolution) and in the presence of the inhibitors 2-oxo-1,2,3,6-tetrahydropyrimidine-4,6-dicarboxylate (HDDP; 2.0 A) and 5-fluoroorotate (FOA, 2.2 A). These are the first crystal structures of DHOase-inhibitor complexes, providing structural information on the mode of inhibitor binding. HDDP possesses features of both the substrate and product, and ligates the Zn atoms in the active site. In addition, HDDP forms hydrogen bonds to the flexible loop (residues 105-115) stabilizing the "loop-in" conformation of the flexible loop normally associated with the presence of CA-asp in the active site. By contrast, FOA, a product-like inhibitor, binds to the active site in a similar fashion to DHO but does not ligate the Zn atoms directly nor stabilize the loop-in conformation. These structures define the necessary features for the future design of improved inhibitors of DHOase.


  • Organizational Affiliation

    School of Molecular and Microbial Biosciences, University of 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
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.214 
  • R-Value Work: 0.174 
  • R-Value Observed: 0.176 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 51.426α = 90
b = 79.674β = 90
c = 180.987γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MAR345dtbdata collection
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-07-03
    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