4BJH : Crystal Structure of the Aquifex Reactor Complex Formed by Dihydroorotase (H180A, H232A) with Dihydroorotate and Aspartate Transcarbamoylase with N-(phosphonacetyl)-L-aspartate (PALA)

  • Philip D. Martin (Contributor)
  • Asmita Vaishnav (Contributor)
  • Joseph S. Brunzelle (Contributor)
  • Roshini Fernando (Contributor)
  • Hedeel I. Guy-Evans (Contributor)
  • David R. Evans (Contributor)
  • Brian F P Edwards (Contributor)
  • Edward Grimley (Contributor)
  • Melissa Cordes (Contributor)
  • Hedeel Guy Evans (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2013-12-18
Deposition Date:2013-04-18
Revision Date:2017-06-28
Molecular Weight:89175.7
Macromolecule Type:Protein
Residue Count:778
Atom Site Count:5706

Dihydroorotase (DHO) is a zinc metalloenzyme, although the number of active site zinc ions has been controversial. E. coli DHO was initially thought to have a mononuclear metal center, but the subsequent X-ray structure clearly showed two zinc ions, α and β, at the catalytic site. Aquifex aeolicus DHO, is a dodecamer comprised of six DHO and six aspartate transcarbamoylase (ATC) subunits. The isolated DHO monomer, which lacks catalytic activity, has an intact α-site and conserved β-site ligands, but the geometry of the second metal binding site is completely disrupted. However, the putative β-site is restored when the complex with ATC is formed and DHO activity is regained. Nevertheless, the X-ray structure of the complex revealed a single zinc ion at the active site. The structure of DHO from the pathogenic organism, S. aureus showed that it also has a single active site metal ion.
Date made available2013

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