Structures of the apo- and the metal ion-activated forms of the diphtheria tox repressor from Corynebacterium diphtheriae Academic Article Article uri icon


MeSH Major

  • National Institutes of Health (U.S.)
  • Translational Medical Research


  • The diphtheria tox repressor (DtxR) of Corynebacterium diphtheriae plays a critical role in the regulation of diphtheria toxin expression and the control of other iron-sensitive genes. The crystal structures of apo-DtxR and of the metal ion-activated form of the repressor have been solved and used to identify motifs involved in DNA and metal ion binding. Residues involved in binding of the activated repressor to the diphtheria tox operator, glutamine 43, arginine 47, and arginine 50, were located and confirmed by site-directed mutagenesis. Previous biochemical and genetic data can be explained in terms of these structures. Conformational differences between apo- and Ni-DtxR are discussed with regard to the mechanism of action of this repressor.

publication date

  • October 10, 1995



  • Academic Article


Digital Object Identifier (DOI)

  • 10.1073/pnas.92.21.9843

PubMed ID

  • 7568230

Additional Document Info

start page

  • 9843

end page

  • 50


  • 92


  • 21