3UB6 : Periplasmic portion of the Helicobacter pylori chemoreceptor TlpB with urea bound

  • Kevin G. Hicks (Contributor)
  • S. James Remington (Contributor)
  • Raghuveer Parthasarathy (Contributor)
  • Karen Guillemin (Contributor)
  • Emily Goers Sweeney (Contributor)
  • John Goers (Contributor)
  • Christopher Wreden (Contributor)
  • Emily Goers Sweeney (Contributor)
  • J. Nathan Henderson (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2012-06-27
Deposition Date:2011-10-23
Revision Date:2013-01-09#2017-11-08
Molecular Weight:42718.3
Macromolecule Type:Protein
Residue Count:362
Atom Site Count:2774

pH sensing is crucial for survival of most organisms, yet the molecular basis of such sensing is poorly understood. Here, we present an atomic resolution structure of the periplasmic portion of the acid-sensing chemoreceptor, TlpB, from the gastric pathogen Helicobacter pylori. The structure reveals a universal signaling fold, a PAS domain, with a molecule of urea bound with high affinity. Through biophysical, biochemical, and in vivo mutagenesis studies, we show that urea and the urea-binding site residues play critical roles in the ability of H. pylori to sense acid. Our signaling model predicts that protonation events at Asp114, affected by changes in pH, dictate the stability of TlpB through urea binding.
Date made availableJun 27 2012

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