Supramolecular assembly and acid resistance of Helicobacter pylori urease

  title={Supramolecular assembly and acid resistance of Helicobacter pylori urease},
  author={Nam-Chul Ha and Sang-Taek Oh and Jae Young Sung and Kyeung Ah Cha and Mann-Hyung Lee and Byung-Ha Oh},
  journal={Nature Structural Biology},
Helicobacter pylori, an etiologic agent in a variety of gastroduodenal diseases, produces a large amount of urease, which is believed to neutralize gastric acid by producing ammonia for the survival of the bacteria. Up to 30% of the enzyme associates with the surface of intact cells upon lysis of neighboring bacteria. The role of the enzyme at the extracellular location has been a subject of controversy because the purified enzyme is irreversibly inactivated below pH 5. We have determined the… 
The gastric biology of Helicobacter pylori.
Deletion of ureI abolishes the ability of the organism to survive in acid and also to colonize the mouse or gerbil stomach, showing that UreI is essential for gastric survival and that the habitat of H. pylori at the gastric surface must fall to pH 3.5 or below.
Staying alive overdosed: how does Helicobacter pylori control urease activity?
Medium pH-dependent redistribution of the urease of Helicobacter pylori.
The first report of the intracellular transport of molecules in bacteria in response to changes in the extracellular environment is reported, suggesting an additional role of UreI in urease-dependent acid resistance.
The Helicobacter pylori UreI protein: role in adaptation to acidity and identification of residues essential for its activity and for acid activation
UreI behaves like a novel type of urea transporter, and the identification of residues essential for its function in H. pylori provides new insight into the unusual molecular mechanism of low pH activation.
Transcriptional Regulation of the Nickel and Iron Metabolism in Helicobacter pylori
The aim of this thesis was to gain further insight into the transcriptional regulation the ferric uptake regulator Fur and the nickel responsive regulator NikR.
Energetics of Helicobacter pylori and Its Implications for the Mechanism of Urease-Dependent Acid Tolerance at pH 1
It is proposed that cytoplasmic pH is a factor in the in vivo activation of the urease at low external pH values and was about pH 5 in sodium citrate buffer in cell extracts.
Molecular Dynamics Study of Helicobacter pylori Urease
The internal hollow cavity of the H. pylori bacterium is discussed and an additional flap in the active site was elaborated upon that may serve as an exit conduit for hydrolysis products and the distribution of sodium ions over the course of the simulation is discussed.
Title Surface properties of Helicobacter pylori urease complex areessential for persistence
Results indicate that a discrete surface of the urease complex is important for H. pylori persistence during gastric colonisation, and it is proposed that this surface interacts directly with host components important for the hostpathogen interaction, immune modulation or other actions that underlie H.pylori persisted in its special gastric mucosal niche.
Adaptation of Helicobacter pylori Metabolism to Persistent Gastric Colonization
It is proposed that the constrains of the small H. pylori genome and a very specialized niche has resulted in a close association and in overlapping networks between mechanisms of persistence, acid adaptation and metabolic pathways.


Helicobacter pylori Containing Only Cytoplasmic Urease Is Susceptible to Acid
It is concluded that cytoplasmic urease activity alone is not sufficient to allow survival of H. pylori in an acid environment and that the activity of surface-localized ure enzyme is essential for resistance ofH.
Surface localization of Helicobacter pylori urease and a heat shock protein homolog requires bacterial autolysis
Investigation of mechanisms whereby urease and HspB, a GroEL homolog, become surface associated in vitro suggests that H. pylori cells undergo spontaneous autolysis during culture and that ure enzyme and HSPB become surfaceassociated only concomitant with bacterial autolytic activity.
Purification and N-terminal analysis of urease from Helicobacter pylori
The amino acid sequence is conserved among ureases with one, two, and three distinct subunits, suggesting a common ancestral urease gene.
Localization of Helicobacter pylori urease and heat shock protein in human gastric biopsies
The results demonstrate that both urease and HspB are located within the cytoplasm of all bacteria examined in human gastric biopsies, indicating that in vivo, H. pylori has surface characteristics which enable it to adsorbed onto the surface of neighboring viable bacteria.
Purification and characterization of the urease enzymes of Helicobacter species from humans and animals
N-terminal amino acid sequencing of the enzyme subunits from the four species revealed high levels of homology, suggesting a common ancestral origin and an important role for the urease enzymes of these organisms.
Synthesis and activity of Helicobacter pylori urease and catalase at low pH.
Low surrounding pH reduces activity of Urease and synthesis of nascent urease, catalase, and presumably of most other proteins, suggesting that H pylori is not acidophilic although it tolerates short-term exposure to low pH.
A H+-gated urea channel: the link between Helicobacter pylori urease and gastric colonization.
Acidic media trigger cytoplasmic urease activity of the unique human gastric pathogen Helicobacter pylori. Deletion of ureI prevents this activation of cytoplasmic urease that is essential for