3UB9: Periplasmic portion of the Helicobacter pylori chemoreceptor TlpB with hydroxyurea bound

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.
PDB ID: 3UB9Download
MMDB ID: 100836
PDB Deposition Date: 2011/10/23
Updated in MMDB: 2017/11
Experimental Method:
x-ray diffraction
Resolution: 1.42  Å
Source Organism:
Similar Structures:
Biological Unit for 3UB9: dimeric; determined by author and by software (PISA)
Molecular Components in 3UB9
Label Count Molecule
Proteins (2 molecules)
Chemoreceptor Tlpb
Molecule annotation
Chemicals (10 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB