1Q0A : Crystal structure of the Zn(II) form of E. coli ZntR, a zinc-sensing transcriptional regulator (space group C222)

  • Anita Changela (Contributor)
  • Kui Chen (Contributor)
  • Yi Xue (Contributor)
  • Jackie Holschen (Contributor)
  • Caryn E. Outten (Contributor)
  • Thomas V. O'Halloran (Contributor)
  • Alfonso Mondragon (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2003-09-16
Deposition Date:2003-07-15
Revision Date:2008-04-29#2011-07-13
Molecular Weight:22742.39
Macromolecule Type:Protein
Residue Count:198
Atom Site Count:1456

The earliest of a series of copper efflux genes in Escherichia coli are controlled by CueR, a member of the MerR family of transcriptional activators. Thermodynamic calibration of CueR reveals a zeptomolar (10(-21) molar) sensitivity to free Cu+, which is far less than one atom per cell. Atomic details of this extraordinary sensitivity and selectivity for +1transition-metal ions are revealed by comparing the crystal structures of CueR and a Zn2+-sensing homolog, ZntR. An unusual buried metal-receptor site in CueR restricts the metal to a linear, two-coordinate geometry and uses helix-dipole and hydrogen-bonding interactions to enhance metal binding. This binding mode is rare among metalloproteins but well suited for an ultrasensitive genetic switch.
Date made available2003

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