title: Helicobacter urease: niche construction at the single molecule level.
abstract: The urease of the human pathogen, Helicobacter pylori, is essential for pathogenesis. The ammonia produced by the enzyme neutralizes stomach acid; thereby modifying its environment. The dodecameric enzyme complex has high affinity for its substrate, urea. We compared urease sequences and derivative 3D homology model structures from all published Helicobacter genomes and an equal number of genomes belonging to strains of another enteric bacterium, Escherichia coli. We found that the enzyme's architecture adapts to fit its niche. This finding, coupled to a survey of other physiological features responsible for the bacterium's acid resistance, suggests how it copes with pH changes caused by disease onset and progression.
authors.affiliation: Department of Lifesciences, School of Science and Engineering, Lahore University of Management Sciences, Lahore 54792, Punjab, Pakistan. shahidkh@lums.edu.pk
authors.forename: Shahid
authors.initials: S
authors.lastname: Khan
authors.forename: Asim
authors.initials: A
authors.lastname: Karim
authors.forename: Shaheryar
authors.initials: S
authors.lastname: Iqbal
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000502:physiology; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D016680:Genome, Bacterial; D016480:Helicobacter pylori / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity; D006706:Homeostasis; D006863:Hydrogen-Ion Concentration; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D013379:Substrate Specificity; D014508:Urea / Q000378:metabolism; D014510:Urease / Q000737:chemistry* / Q000502:physiology
chemical_list: D001426:Bacterial Proteins; D014508:Urea; D014510:Urease