Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
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Prenatal intrauterine infection has been recognized as an important cause of premature birth, and Ureaplasma urealyticum is one of the commonest pathogens. U. urealyticum consists of 14 serovars that can be divided into two biovars (parvo and T960), and the pathogenicity of U. urealyticum may be different according to the biovar. To detect U. urealyticum and determine its biovar simultaneously, we developed a real-time polymerase chain reaction (PCR) assay targeting urease gene. The real-time PCR biovar-typed two reference strains and 42 culture isolates of U. urealyticum as correctly as conventional PCR with direct sequencing. Subsequently, 87 clinical specimens (amniotic fluid, cord blood, vaginal swab) were tested for culture, conventional PCR, and real-time PCR. When compared with conventional PCR, sensitivity and specificity of real-time PCR were 89.5 and 98.5%, respectively, and those of culture were 47.4 and 100%, respectively. Of 18 clinical specimens that were found positive and biovar-typed by real-time PCR, parvo biovar was 66.7% and T960 biovar was 33.3%. This real-time PCR assay can be useful for the simultaneous detection and biovar discrimination of U. urealyticum in clinical specimens. Further study to quantify U. urealyticum would be facilitated on the basis of this method.
Mol Cell Probes 2005 Aug
PMID:Detection and biovar discrimination of Ureaplasma urealyticum by real-time PCR. 1600 82

Paracoccidioides brasiliensis, the etiologic agent of paracoccidioidomycosis, is a dimorphic fungus, which is found as mycelia at 22-26 degrees C and as yeasts at 37 degrees C. A remarkable feature common to several pathogenic fungi is their ability to differentiate from mycelium to yeast morphologies, or vice-versa. Although P. brasiliensis is a recognized pathogen for humans, little is known about its virulence genes. In this sense, we performed a search for putative virulence genes in the P. brasiliensis transcriptome. BLAST comparative analyses were done among P. brasilienses assembled expressed sequence tags (PbAESTs) and the sequences deposited in GenBank. As a result, the putative virulence PbAESTs were grouped into five classes, metabolism-, cell wall-, detoxification-related, secreted factors, and other determinants. Among these, we have identified orthologs of the glyoxylate cycle enzymes, a metabolic pathway involved in the virulence of bacteria and fungi. Besides the previously described alpha- and beta-glucan synthases, orthologs to chitin synthase and mannosyl transferases, also important in cell wall synthesis and stabilization, were identified. With respect to the enzymes involved in the intracellular survival of P. brasiliensis, orthologs to superoxide dismutase, thiol peroxidase and an alternative oxidase were also found. Among the secreted factors, we were able to find phospholipase and urease orthologs in P. brasiliensis transcriptome. Collectively, our results suggest that this organism may possess a vast arsenal of putative virulence genes, allowing the survival in the different host environments.
Genet Mol Res 2005 Jun 30
PMID:Virulence insights from the Paracoccidioides brasiliensis transcriptome. 1611 Apr 52

The roles that accessory gene products play in activating the Helicobacter pylori urease apoprotein were examined. The activity of the urease apoprotein increased in the following order when it was expressed with the accessory genes: ureG<ureGH<ureFGH<ureEFGH<ureIEFGH. Moreover, stepwise additions of ureE and ureI to ureFGH significantly increased urease activity. Urease apoproteins coexpressed with ureFGH, ureEFGH, and ureIEFGH had similar low chymotrypsin susceptibilities. In vivo and in vitro activation studies showed that the cooperative effect of the accessory proteins involved processes in which the UreFGH complex, UreE, and UreI were implicated. Thus, the UreFGH complex may serve to alter the conformation of the apoprotein into one that is more competent to assemble a stable metallocenter, and that facilitates cooperative effects.
Mol Cells 2005 Dec 31
PMID:Effect of the urease accessory genes on activation of the Helicobacter pylori urease apoprotein. 1640 52

By using internal combinatorial library we were able to identify (4R)-thiazolidines carboxylic acid and its 2-substituted analogs as active inhibitors of urease. Molecular modeling and virtual screening were utilized to find out potential compounds. Computational techniques were employed at database of 90,000 ligands and selected the structure representing the low energy conformations, Grid and FlexX docking algorithms were used and the top binding ligands were synthesized and screened in wet-lab.
Mol Divers 2006 May
PMID:Successful computer guided planned synthesis of (4R)-thiazolidine carboxylic acid and its 2-substituted analogues as urease inhibitors. 1671 Aug 11

The aim of this study was determination and comparison of the levels of myeloperoxidase (MPO), xanthine oxidase (XO), and superoxide dismutase (SOD) in gastric mucosa of children who were infected and noninfected with Helicobacter pylori (HP). The MPO, and XO enzyme activities were detected via kinetic measurement, and the MPO, XO and SOD enzyme protein levels were detected via Western blot, in antral mucosa specimens of 43 patients who underwent upper gastrointestinal endoscopy with various indications. The diagnosis of HP infection was made with a positive rapid urease test and histopathologic detection. MPO activity and enzyme protein levels were measured in 14 [8 HP (+) and 6 HP (-)], and in 9 [5 HP (+) and 4 HP (-)] while XO activity and enzyme protein levels were measured in 16 [10 HP (+) and 6 HP (-)] and in 9 [5 HP (+) and 4 HP (-)] patients, respectively. SOD protein level was detected in 13 [7 HP (+) and 6 HP (-)] patients. Of 43 patients 25 were HP (+) and 18 were HP (-). MPO activities were 75.6 +/- 40.5 and 98.8 +/- 44.1 U/g. protein (p = 0.302) while XO activities were 0.5 +/- 0.3 and 0.4 +/- 0.2 U/g. protein in HP (+) and HP (-) patients, respectively (p = 0.625). Measured enzyme protein levels of MPO, XO and SOD were found statistically indifferent in HP (+) and HP (-) patients (p = 0.327, p = 0.086, and p = 0.775, respectively). The results of this study revealed that, MPO, XO and SOD conditions in gastric mucosa alone were not affected from HP presence. That's why MPO, XO, and SOD may not have important roles in the pathogenesis of HP related gastric disease in children.
Mol Cell Biochem 2006 Oct
PMID:Myeloperoxidase, xanthine oxidase and superoxide dismutase in the gastric mucosa of Helicobacter pylori positive and negative pediatric patients. 1675 2

The survival of Helicobacter pylori in the human stomach critically relies on the availability and use of nickel, an absolute cofactor of the important virulence determinant urease. Nickel-responsive gene regulation is mediated by HpNikR, a protein belonging to the ribbon-helix-helix family of transcriptional regulators. Unlike its homologues, HpNikR acts as both a repressor and an activator within an acid adaptation cascade. We report the crystal structure of the full-length HpNikR in a nickel-free conformation and two nickel-bound structures obtained in different conditions: Ni1-HpNikR and Ni2-HpNikR. Apo-HpNikR shows the same global fold as its bacterial homologues although with an unusual closed trans-conformation and asymmetrical quaternary arrangement. The structure of Ni1-HpNikR in the presence of nickel has two different sides, one showing nickel binding similar to that of known NikRs and the other reflecting an intermediate state. The structure of Ni2-HpNikR obtained using a shorter exposure to nickel provides another snapshot of the nickel incorporation. Altogether, the three structures have allowed us to determine the route for nickel within HpNikR and reveal the cooperativity between the tetramerization domain and the DNA-binding domain. Experiments using point mutations of HpnikR residues involved in nickel internalisation confirm that these residues are critical for HpNikR functions in vivo.
J Mol Biol 2006 Aug 25
PMID:Structural basis of the nickel response in Helicobacter pylori: crystal structures of HpNikR in Apo and nickel-bound states. 1687 29

Amplified fragment-length polymorphism analysis (AFLP) has been shown to be a suitable method for subtyping of bacteria belonging to the genus Campylobacter. Campylobacter lari is a phenotypically and genotypically diverse species that comprises the classical nalidixic acid-resistant thermophilic campylobacters and the biochemical C. lari variants, urease-positive, nalidixic acid-susceptible, and urease producing nalidixic acid-susceptible strains. AFLP profiling and whole-cell protein profile analysis are suitable methods for studying the taxonomic and epidemiological relationships among strains of the C. lari variants. Numerical analysis of AFLP profiles and of partial protein profiles allows the discrimination of distinct C. lari genogroups. No correlation of these genogroups with different sources of the strains has been identified until now.
Methods Mol Biol 2006
PMID:Amplified fragment-length polymorphism and protein profiling for identification of Campylobacter lari subgroups. 1695 52

The study of protein interactions constitutes an important domain to understand the physiology and pathogenesis of microorganisms. The two-dimensional blue native/SDS-PAGE was initially reported to analyze membrane protein complexes. In this study, both cytoplasmic and membrane complexes of a bacterium, the strain J99 of the gastric pathogen Helicobacter pylori, were analyzed by this method. It was possible to identify 34 different proteins grouped in 13 multiprotein complexes, 11 from the cytoplasm and two from the membrane, either previously reported partially or totally in the literature. Besides complexes involved in H. pylori physiology, this method allowed the description of interactions involving known pathogenic factors such as (i) urease with the heat shock protein GroEL or with the putative ketol-acid reductoisomerase IlvC and (ii) the cag pathogenicity island CagA protein with the DNA gyrase GyrA as well as insight on the partners of TsaA, a peroxide reductase/stress-dependent molecular chaperone. The two-dimensional blue native/SDS-PAGE combined with mass spectrometry is a potential tool to study the differences in complexes isolated in various situations and also to study the interactions between bacterial and eucaryotic cell proteins.
Mol Cell Proteomics 2007 Feb
PMID:Two-dimensional blue native/SDS gel electrophoresis of multiprotein complexes from Helicobacter pylori. 1709 30

Two new soybean [Glycine max (L.) Merr. cv. Williams] loci, designated Eu2 and Eu3, were identified in which ethyl methanesulfonate (EMS)-induced mutation eliminated urease activity. These loci showed no linkage to each other or to the "Sun-Eul" locus described in the accompanying paper (Meyer-Bothling and Polacco 1987). Unlike sun (seed urease-null) mutations those at Eu2 and Eu3 affected both urease isozymes: the embryo-specific (seed) and the ubiquitous (leaf) urease. The eu2/eu2 mutant had no leaf activity and 0.6% normal seed activity. Two mutant Eu3 alleles were recovered, eu3-e1 and Eu3-e3. The eu3-e1/eu3-e1 genotype lacked both activities while Eu3-e3/Eu3-e3 had coordinately reduced leaf (0.1%) and seed (0.1%) activities. Only the Eu3-e3 mutation showed partial dominance, yielding about 5%-10% normal activity for each urease in the heterozygous state. Each homozygous mutant contained normal levels of embryo-specific urease mRNA and protein subunit, both of normal size. However, urease polymerization was aberrant in all three mutants. In all cases where urease could be measured, it was found to be temperature sensitive and, in addition, the embryo-specific urease of Eu3-e3/Eu3-e3 had an altered pH dependence. These mutants may be defective in a urease maturation function common to both isozymes as suggested by the normal levels of urease gene product, coordinately (or nearly so) reduced urease isozyme activities, temperature sensitivity in both ureases (Eu3-e3) and the non-linkage of Eu2 and Eu3 to the locus encoding embryo-specific urease (Sun-Eul). Ubiquitous urease activity is reduced in mutant seed coat and callus culture as well as in leaf and cotyledon tissue. No mutant callus utilized urea (5 to 10 nM0 as sole nitrogen source. However, all mutant cell lines tolerated normally toxic levels of urea (25 to 250 mM) added to medium containing KNO3/NH4No3 as nitrogen source. Urea thus may be used in cell culture as a selection agent for phenotypes either lacking or regaining an active ubiquitous urease.
Mol Gen Genet 1987 Oct
PMID:Pleiotropic soybean mutants defective in both urease isozymes. 1719 6

By a non-destructive urease screen of M2 soybean (Glycine max [L.] Merr. cv. Williams) seeds, four true-breeding mutants (n4, n6, n7 and n8) were recovered which lack most (n6, n8) or all (n4, n7) embryo-specific urease activity. This trait was due to a single, recessive lesion at the Sun (seed urease-null) locus identified earlier in an exotic germplasm (PI 229324, Itachi). All sun mutants produced normal ubiquitous urease, the low abundance isozyme found in all soybean tissues examined. Tight mutants n4 and n7 accumulated no detectable embryo-specific urease protein or mRNA; n6 and n8 accumulated normal or near normal levels of urease mRNA but had seed urease protein levels approximately 5% and .05%, respectively, of the progenitor. Mutant n8 appeared to produce a low level of fully active urease (approximately 0.7% activity level, approximately 0.5% protein level) while n6 produced a higher level of an altered, nearly inactive urease (.0.09% activity level, approximately 5% protein level). Urease alterations in n6 were manifested by its increased temperature sensitivity and variation in aggregation state and pH preference. Thus, mutations in the Sun locus affected both the level and the nature of the embryo-specific urease gene products indicating that Sun encodes the embryo-specific urease. We reported earlier that the Eul locus, which controls the aggregation state of the embryo-specific urease, is on mep unit from Sun and that the Eul allele is cis to sun is not expressed (Kloth et al. 1987). That the level of urease gene product, its aggregation state and other enzyme properties can be affected by induced sun mutations, suggests that the Eul and sun alleles are at the same locus.
Mol Gen Genet 1987 Oct
PMID:Mutational analysis of the embryo-specific urease locus of soybean. 1719 7


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