4C6C

Crystal structure of the dihydroorotase domain of human CAD in apo- form obtained recombinantly from HEK293 cells.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.148 
  • R-Value Work: 0.122 
  • R-Value Observed: 0.124 

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This is version 1.1 of the entry. See complete history


Literature

Structure, Functional Characterization and Evolution of the Dihydroorotase Domain of Human Cad.

Grande-Garcia, A.Lallous, N.Diaz-Tejada, C.Ramon-Maiques, S.

(2014) Structure 22: 185

  • DOI: 10.1016/j.str.2013.10.016
  • Primary Citation of Related Structures:  
    4C6B, 4C6C, 4C6D, 4C6E, 4C6F, 4C6O, 4C6P, 4C6Q, 4C6I, 4C6J

  • PubMed Abstract: 
  • Upregulation of CAD, the multifunctional protein that initiates and controls the de novo biosynthesis of pyrimidines in animals, is essential for cell proliferation. Deciphering the architecture and functioning of CAD is of interest for its potential usa ...

    Upregulation of CAD, the multifunctional protein that initiates and controls the de novo biosynthesis of pyrimidines in animals, is essential for cell proliferation. Deciphering the architecture and functioning of CAD is of interest for its potential usage as an antitumoral target. However, there is no detailed structural information about CAD other than that it self-assembles into hexamers of ∼1.5 MDa. Here we report the crystal structure and functional characterization of the dihydroorotase domain of human CAD. Contradicting all assumptions, the structure reveals an active site enclosed by a flexible loop with two Zn²⁺ ions bridged by a carboxylated lysine and a third Zn coordinating a rare histidinate ion. Site-directed mutagenesis and functional assays prove the involvement of the Zn and flexible loop in catalysis. Comparison with homologous bacterial enzymes supports a reclassification of the DHOase family and provides strong evidence against current models of the architecture of CAD.


    Organizational Affiliation

    Structural Bases of Genome Integrity Group, Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), 28029 Madrid, Spain. Electronic address: sramon@cnio.es.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
CAD PROTEIN A393Homo sapiensMutation(s): 0 
Gene Names: CAD
EC: 6.3.5.5 (UniProt), 2.1.3.2 (UniProt), 3.5.2.3 (UniProt)
Find proteins for P27708 (Homo sapiens)
Explore P27708 
Go to UniProtKB:  P27708
NIH Common Fund Data Resources
PHAROS:  P27708
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.45 Å
  • R-Value Free: 0.148 
  • R-Value Work: 0.122 
  • R-Value Observed: 0.124 
  • Space Group: C 2 2 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 82.11α = 90
b = 158.8β = 90
c = 60.76γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling
PHASERphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-01-08
    Type: Initial release
  • Version 1.1: 2014-02-19
    Changes: Database references