bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunoglobulin E Reactivity of Recombinant Allergen Tyr p 13 from
Tyrophagus putrescentiae
Homologous to Fatty Acid Binding Protein
Authors: Jeong Kyoung Yong , Kim Woo Kyung , Lee Jae Sik , Lee Jongweon , Lee In-Yong , Kim Kyu-Earn , Park Jung Won , Hong Chein-Soo , Ree Han-Il , Yong Tai-Soon 
Published: May 2005

ABSTRACT

The storage mite,
Tyrophagus putrescentiae
, is one of the important causes of allergic disorders. Fifteen allergenic components were demonstrated in storage mite by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting, but only the group 2 allergen Tyr p 2 has been cloned and characterized. In this study, we attempted to identify and characterize new allergens from
T. putrescentiae
, which is a dominant species of storage mite in Korea. Expressed sequence tags were analyzed to identify possible storage mite allergens, and the cDNA sequence encoding a protein homologous to fatty acid binding protein, a mite group 13 allergen, was identified and named Tyr p 13. Its deduced amino acid sequence showed 61.1 to 85.3% identity with other mite group 13 allergens. The recombinant protein was expressed in
Escherichia coli
using a pET 28b vector system, and its allergenicity was investigated by enzyme-linked immunosorbent assay (ELISA). The recombinant allergen was detected in 5 of 78 (6.4%)
T. putrescentiae
-positive sera tested, and it inhibited 61.9% of immunoglobulin E binding to crude extract at an inhibitor concentration of 10 μg/ml by inhibition ELISA using serum from the patient who showed the strongest reaction by ELISA. In this study, a novel allergen was identified in
T. putrescentiae
. This allergen could be helpful for more-detailed characterizations of storage mite allergy.
Development of Recombinant Chimeric Antigen Expressing Immunodominant B Epitopes ofLeishmania infantumfor Serodiagnosis of Visceral Leishmaniasis
Authors: Boarino A. , Scalone A. , Gradoni L. , Ferroglio E. , Vitale F. , Zanatta R. , Giuffrida M. G. , Rosati S. 
Published: May 2005

ABSTRACTWild canids and domestic dogs are the main reservoir of zoonotic visceral leishmaniasis (VL) caused byLeishmania infantum(syn.:Leishmania chagasi). Serological diagnosis of VL is therefore important in both human and dog leishmaniasis from a clinical and epidemiological point of view. Routine diagnosis of VL is traditionally carried out by immunofluorescent antibody test (IFAT), which is laborious and difficult to standardize and to interpret. In the last decade, however, several specific antigens ofLeishmania infantumhave been characterized, allowing the development of a recombinant-based immunoassay. Among them, the whole open reading frame encoding K9 antigen, the gene fragment encoding the repetitive sequence of K26, and the 3′-terminal gene fragment of the kinesin-related protein (K39sub) were previously evaluated as diagnostic markers for canine leishmaniasis and proved to be independent in their antibody reactivity. Since sensitivity of serological test is usually higher in multiple-epitope format, in this study the relevant epitopes of K9, K26, and K39 antigens were joined by PCR strategy to produce the chimeric recombinant protein. The resulting mosaic antigen was found highly expressed inEscherichia coliand efficiently purified by affinity chromatography. Antigenic properties of this recombinant antigen were evaluated by indirect enzyme-linked immunosorbent assay (ELISA) using a panel of human and dog sera previously characterized by parasitological and/or serological techniques. Chimeric ELISA showed 99% specificity in both human (n= 180) and canine (n= 343) control groups, while sensitivity was higher in canine VL (96%,n= 213) than in human VL (82%,n= 185). Accordingly, concordance between IFAT and canine chimeric ELISA (k= 0.95, 95% confidence interval = 0.93 to 0.98) was higher than between IFAT and human chimeric ELISA (k= 0.81, 95% confidence interval = 0.76 to 0.87). Results suggest the potential use of this new antigen for routine serodiagnosis of VL in both human and canine hosts.
Detection by Radioligand Assay of Antibodies against Borna Disease Virus in Patients with Various Psychiatric Disorders
Authors: Matsunaga Hidenori , Tanaka Susumu , Sasao Fuyoko , Nishino Yoshii , Takeda Masatoshi , Tomonaga Keizo , Ikuta Kazuyoshi , Amino Nobuyuki 
Published: May 2005

ABSTRACT
Using a radioligand assay, which preserves the natural form of the antigen, antibodies against Borna disease virus nucleoprotein and phosphoprotein were detected in 11 and 19 sera of 171 psychiatric patients, respectively. Compared with results by Western blotting, three and nine sera were concordantly positive, respectively. The four sera showing the highest levels of antibodies by radioligand assay were all negative by Western blotting; however, dilution and inhibition tests supported the positive results. Our results suggest the importance of conformational structure to detect human anti-Borna disease virus antibodies.
Strongyloides Hyperinfection and Hypogammaglobulinemia
Authors: Seet Raymond C. S. , Lau Lee Gong , Tambyah Paul Ananth 
Published: May 2005

ABSTRACT
We report strongyloides hyperinfection in two patients with generalized hypogammaglobulinemia from multiple myeloma and nephrotic syndrome, despite a significant strongyloides-specific immunoglobulin G (IgG) response. In contrast to reports on animals, where human IgG was shown to be a protective antibody, our observation suggests that in humans, immunity to the infective-stage larvae is not protective against the autoinfective larvae, which are the causative agents of strongyloides hyperinfection.
Respiration and Growth of
Shewanella oneidensis
MR-1 Using Vanadate as the Sole Electron Acceptor
Authors: Carpentier Wesley , De Smet Lina , Van Beeumen Jozef , Brigé Ann 
Published: May 2005

ABSTRACT

Shewanella oneidensis
MR-1 is a free-living gram-negative γ-proteobacterium that is able to use a large number of oxidizing molecules, including fumarate, nitrate, dimethyl sulfoxide, trimethylamine
N
-oxide, nitrite, and insoluble iron and manganese oxides, to drive anaerobic respiration. Here we show that
S. oneidensis
MR-1 is able to grow on vanadate as the sole electron acceptor. Oxidant pulse experiments demonstrated that proton translocation across the cytoplasmic membrane occurs during vanadate reduction. Proton translocation is abolished in the presence of protonophores and the inhibitors 2-heptyl-4-hydroxyquinoline
N
-oxide and antimycin A. Redox difference spectra indicated the involvement of membrane-bound menaquinone and cytochromes
c
, which was confirmed by transposon mutagenesis and screening for a vanadate reduction-deficient phenotype. Two mutants which are deficient in menaquinone synthesis were isolated. Another mutant with disruption in the cytochrome
c
maturation gene
ccmA
was unable to produce any cytochrome
c
and to grow on vanadate. This phenotype could be restored by complementation with the pEC86 plasmid expressing
ccm
genes from
Escherichia coli
. To our knowledge, this is the first report of
E. coli ccm
genes being functional in another organism. Analysis of an
mtrB
-deficient mutant confirmed the results of a previous paper indicating that OmcB may function as a vanadate reductase or may be part of a vanadate reductase complex.
Global Transcriptional and Proteomic Analysis of the Sig1 Heat Shock Regulon ofDeinococcus radiodurans
Authors: Schmid Amy K. , Howell Heather A. , Battista John R. , Peterson Scott N. , Lidstrom Mary E. 
Published: May 2005

ABSTRACTThesig1gene, predicted to encode an extracytoplasmic function-type heat shock sigma factor ofDeinococcus radiodurans, has been shown to play a central role in the positive regulation of the heat shock operonsgroESLanddnaKJ.To determine if Sig1 is required for the regulation of additional heat shock genes, we monitored the global transcriptional and proteomic profiles of aD. radioduransR1sig1mutant and wild-type cells in response to elevated temperature stress. Thirty-one gene products were identified that showed heat shock induction in the wild type but not in thesig1mutant. Quantitative real-time PCR experiments verified the transcriptional requirement of Sig1 for the heat shock induction of the mRNA of five of these genes—dnaK,groES, DR1314,pspA, andhsp20. hsp20appears to encode a new member of the small heat shock protein superfamily, DR1314 is predicted to encode a hypothetical protein with no recognizable orthologs, andpspAis predicted to encode a protein involved in maintenance of membrane integrity. Deletion mutation analysis demonstrated the importance in heat shock protection ofhsp20and DR1314. The promoters ofdnaKJE,groESL, DR1314,pspA, andhsp20were mapped and, combined with computer-based pattern searches of the upstream regions of the 26 other Sig1 regulon members, these results suggested that Sig1 might recognize both σ70-type and σW-type promoter consensus sequences. These results expand theD. radioduransSig1 heat shock regulon to include 31 potential new members, including not only factors with cytoplasmic functions, such asgroESanddnaK, but also those with extracytoplasmic functions, likepspA.
Horizontal Transfer of the High-Pathogenicity Island ofYersinia pseudotuberculosis
Authors: Lesic Biliana , Carniel Elisabeth 
Published: May 2005

ABSTRACTThe horizontal transfer of genetic elements plays a major role in bacterial evolution. The high-pathogenicity island (HPI), which codes for an iron uptake system, is present and highly conserved in variousEnterobacteriaceae, suggesting its recent acquisition by lateral gene transfer. The aim of this work was to determine whether the HPI has kept its ability to be transmitted horizontally. We demonstrate here that the HPI is indeed transferable from a donor to a recipientYersinia pseudotuberculosisstrain. This transfer was observable only when the donor and recipient bacteria were cocultured at low temperatures in a liquid medium. When optimized conditions were used (bacteria actively growing in an iron-deprived medium at 4°C), the frequency of HPI transfer reached ∼10−8. The island was transferable to various serotype I strains ofY. pseudotuberculosisand toYersinia pestis, but not toY. pseudotuberculosisstrains of serotypes II and IV or toYersinia enterocolitica. Upon transfer, the HPI was inserted almost systematically into theasn3tRNA locus. Acquisition of the HPI resulted in the loss of the resident island, suggesting an incompatibility between two copies of the HPI within the same strain. Transfer of the island did not require a functional HPI-borne insertion-excision machinery and was RecA dependent in the recipient but not the donor strain, suggesting that integration of the island into the recipient chromosome occurs via a mechanism of homologous recombination. This lateral transfer also involved the HPI-adjacent sequences, leading to the mobilization of a chromosomal region at least 46 kb in size.
Defective O-Antigen Polymerization intolAandpalMutants ofEscherichia coliin Response to Extracytoplasmic Stress
Authors: Vinés Enrique D. , Marolda Cristina L. , Balachandran Aran , Valvano Miguel A. 
Published: May 2005

ABSTRACTWe have previously shown that the TolA protein is required for the correct surface expression of theEscherichia coliO7 antigen lipopolysaccharide (LPS). In this work, ΔtolAand Δpalmutants ofE. coliK-12 W3110 were transformed with pMF19 (encoding a rhamnosyltransferase that reconstitutes the expression of O16-specific LPS), pWQ5 (encoding theKlebsiella pneumoniaeO1 LPS gene cluster), or pWQ802 (encoding the genes necessary for the synthesis ofSalmonella entericaO:54). Both ΔtolAand Δpalmutants exhibited reduced surface expression of O16 LPS as compared to parental W3110, but no significant differences were observed in the expression ofK. pneumoniaeO1 LPS andS. entericaO:54 LPS. Therefore, TolA and Pal are required for the correct surface expression of O antigens that are assembled in awzy(polymerase)-dependent manner (like those ofE. coliO7 and O16) but not for O antigens assembled bywzy-independent pathways (likeK. pneumoniaeO1 andS. entericaO:54). Furthermore, we show that the reduced surface expression of O16 LPS in ΔtolAand Δpalmutants was associated with a partial defect in O-antigen polymerization and it was corrected by complementation with intacttolAandpalgenes, respectively. Using derivatives of W3110ΔtolAand W3110ΔpalcontaininglacZreporter fusions tofkpAanddegP, we also demonstrate that the RpoE-mediated extracytoplasmic stress response is upregulated in these mutants. Moreover, an altered O16 polymerization was also detected under conditions that stimulate RpoE-mediated extracytoplasmic stress responses intol+andpal+genetic backgrounds. A Wzy derivative with an epitope tag at the C-terminal end of the protein was stable in all the mutants, ruling out stress-mediated proteolysis of Wzy. We conclude that the absence of TolA and Pal elicits a sustained extracytoplasmic stress response that in turn reduces O-antigen polymerization but does not affect the stability of the Wzy O-antigen polymerase.
In Vitro Characterization of theBacillus subtilisProtein Tyrosine Phosphatase YwqE
Authors: Mijakovic Ivan , Musumeci Lucia , Tautz Lutz , Petranovic Dina , Edwards Robert A. , Jensen Peter Ruhdal , Mustelin Tomas , Deutscher Josef , Bottini Nunzio 
Published: May 2005

ABSTRACTBoth gram-negative and gram-positive bacteria possess protein tyrosine phosphatases (PTPs) with a catalytic Cys residue. In addition, many gram-positive bacteria have acquired a new family of PTPs, whose first characterized member was CpsB fromStreptococcus pneumoniae. Bacillus subtiliscontains one such CpsB-like PTP, YwqE, in addition to two class II Cys-based PTPs, YwlE and YfkJ. The substrates for both YwlE and YfkJ are presently unknown, while YwqE was shown to dephosphorylate two phosphotyrosine-containing proteins implicated in UDP-glucuronate biosynthesis, YwqD and YwqF. In this study, we characterize YwqE, compare the activities of the threeB. subtilisPTPs (YwqE, YwlE, and YfkJ), and demonstrate that the twoB. subtilisclass II PTPs do not dephosphorylate the physiological substrates of YwqE.
Identification of
cptA
, a PmrA-Regulated Locus Required for Phosphoethanolamine Modification of the
Salmonella enterica
Serovar Typhimurium Lipopolysaccharide Core
Authors: Tamayo R. , Choudhury B. , Septer A. , Merighi M. , Carlson R. , Gunn J. S. 
Published: May 2005

ABSTRACT

In response to the in vivo environment, the
Salmonella enterica
serovar Typhimurium lipopolysaccharide (LPS) is modified. These modifications are controlled in part by the two-component regulatory system PmrA-PmrB, with the addition of 4-aminoarabinose (Ara4N) to the lipid A and phosphoethanolamine (pEtN) to the lipid A and core. Here we demonstrate that the PmrA-regulated STM4118 (
cptA
) gene is necessary for the addition of pEtN to the LPS core.
pmrC
, a PmrA-regulated gene necessary for the addition of pEtN to lipid A, did not affect core pEtN addition. Although imparting a similar surface charge modification as Ara4N, which greatly affects polymyxin B resistance and murine virulence, neither
pmrC
nor
cptA
plays a dramatic role in antimicrobial peptide resistance in vitro or virulence in the mouse model. Therefore, factors other than surface charge/electrostatic interaction contribute to resistance to antimicrobial peptides such as polymyxin B.
Mechanisms of Strand Replacement Synthesis for Plasmid DNA Transferred by Conjugation
Authors: Parker Christopher , Meyer Richard 
Published: May 2005

ABSTRACT

A single strand of plasmid DNA is transferred during conjugation. We examined the mechanism of complementary strand synthesis in recipient cells following conjugative mobilization of derivatives of the IncQ plasmid R1162. A system for electroporation of donor cells, followed by immediate mating, was used to eliminate plasmid-specific replicative functions. Under these conditions,
Escherichia coli
recipients provided a robust mechanism for initiation of complementary strand synthesis on transferred DNA. In contrast, plasmid functions were important for efficient strand replacement in recipient cells of
Salmonella enterica
serovar Typhimurium. The mobilizing vector for R1162 transfer, the IncP1 plasmid R751, encodes a DNA primase with low specificity for initiation. This protein increased the frequency of transfer of R751 into
Salmonella
, but despite its low specificity, it was inactive on the R1162 derivatives. The R751 primase was slightly inhibitory for the transfer of both R751 and R1162 into
E. coli
. The results show that there is a chromosomally encoded mechanism for complementary strand synthesis of incoming transferred DNA in
E. coli
, while plasmid-specific mechanisms for this synthesis are important in
Salmonella
.
Role ofMycobacterium tuberculosisSer/Thr Kinase PknF: Implications in Glucose Transport and Cell Division
Authors: Deol Parampal , Vohra Reena , Saini Adesh Kumar , Singh Amit , Chandra Harish , Chopra Puneet , Das Taposh K. , Tyagi Anil K. , Singh Yogendra 
Published: May 2005

ABSTRACTProtein kinases have a diverse array of functions in bacterial physiology, with a distinct role in the regulation of development, stress responses, and pathogenicity.pknF, one of the 11 kinases ofMycobacterium tuberculosis, encodes an autophosphorylating, transmembrane serine/threonine protein kinase, which is absent in the fast-growing, nonpathogenicMycobacterium smegmatis. Herein, we investigate the physiological role of PknF using an antisense strategy withM. tuberculosisand expressing PknF and its kinase mutant (K41M) inM. smegmatis. Expression of PknF inM. smegmatisled to reduction in the growth rate and shortening and swelling of cells with constrictions. Interestingly, an antisense strain ofM. tuberculosisexpressing a low level of PknF displayed fast growth and a deformed cell morphology compared to the wild-type strain. Electron microscopy showed that most of the cells of the antisense strain were of a smaller size with an aberrant septum. Furthermore, nutrient transport analysis of these strains was conducted using3H-labeled and14C-labeled substrates. A significant increase in the uptake ofd-glucose but not of glycerol, leucine, or oleic acid was observed in the antisense strain compared to the wild-type strain. The results suggest that PknF plays a direct/indirect role in the regulation of glucose transport, cell growth, and septum formation inM. tuberculosis.
Piv Site-Specific Invertase Requires a DEDD Motif Analogous to the Catalytic Center of the RuvC Holliday Junction Resolvases
Authors: Buchner John M. , Robertson Anne E. , Poynter David J. , Denniston Shelby S. , Karls Anna C. 
Published: May 2005

ABSTRACT

Piv, a unique prokaryotic site-specific DNA invertase, is related to transposases of the insertion elements from the IS
110
/IS
492
family and shows no similarity to the site-specific recombinases of the tyrosine- or serine-recombinase families. Piv tertiary structure is predicted to include the RNase H-like fold that typically encompasses the catalytic site of the recombinases or nucleases of the retroviral integrase superfamily, including transposases and RuvC-like Holliday junction resolvases. Analogous to the DDE and DEDD catalytic motifs of transposases and RuvC, respectively, four Piv acidic residues D9, E59, D101, and D104 appear to be positioned appropriately within the RNase H fold to coordinate two divalent metal cations. This suggests mechanistic similarity between site-specific inversion mediated by Piv and transposition or endonucleolytic reactions catalyzed by enzymes of the retroviral integrase superfamily. The role of the DEDD motif in Piv catalytic activity was addressed using Piv variants that are substituted individually or multiply at these acidic residues and assaying for in vivo inversion, intermolecular recombination, and DNA binding activities. The results indicate that all four residues of the DEDD motif are required for Piv catalytic activity. The DEDD residues are not essential for
inv
recombination site recognition and binding, but this acidic tetrad does appear to contribute to the stability of Piv-
inv
interactions. On the basis of these results, a working model for Piv-mediated inversion that includes resolution of a Holliday junction is presented.
The Iron-Regulated
iupABC
Operon Is Required for Saprophytic Growth of the Intracellular Pathogen
Rhodococcus equi
at Low Iron Concentrations
Authors: Miranda-CasoLuengo Raúl , Duffy Pamela S. , O'Connell Enda P. , Graham Brian J. , Mangan Michael W. , Prescott John F. , Meijer Wim G. 
Published: May 2005

ABSTRACT

Rhodococcus equi
is a facultative intracellular pathogen which proliferates rapidly in both manure-enriched soil and alveolar macrophages. Although both environments are characterized by extremely low concentrations of free iron, very little is known regarding the strategies employed by
R. equi
to thrive under these conditions. This paper reports the characterization of an
R. equi
transposome mutant that fails to grow at low iron concentrations. The transposome was shown to be inserted into
iupA
, the first gene of the
iupABC
operon encoding an ABC transport system highly similar to siderophore uptake systems. Disruption of the
iupA
gene also resulted in a failure of
R. equi
to utilize heme and hemoglobin as a source of iron. Introduction of the
iupABC
operon in
trans
restored the wild-type phenotype of the mutant strain.
iupABC
transcripts were 180-fold more abundant in
R. equi
grown in iron-depleted medium than in organisms grown in iron-replete medium. Proliferation of the
iupABC
mutant strain in macrophages was comparable to that of the wild-type strain. Furthermore, the
iupABC
mutant was not attenuated in mice, showing that the
iupABC
operon is not required for virulence.
The
repA
Gene of the Linear
Yersinia enterocolitica
Prophage PY54 Functions as a Circular Minimal Replicon in
Escherichia coli
Authors: Ziegelin Günter , Tegtmeyer Nicole , Lurz Rudi , Hertwig Stefan , Hammerl Jens , Appel Bernd , Lanka Erich 
Published: May 2005

ABSTRACT

The
Yersinia enterocolitica
prophage PY54 replicates as a linear DNA molecule with covalently closed ends. For replication of a circular PY54 minimal replicon that has been derived from a linear minireplicon, two phage-encoded loci are essential in
Escherichia coli
: (i) the reading frame of the replication initiation gene
repA
and (ii) its 212-bp origin located within the 3′ portion of
repA
. The RepA protein acts in
trans
on the origin since we have physically separated the PY54 origin and
repA
onto a two-plasmid origin test system. For this
trans
action, the
repA
3′ end carrying the origin is dispensable. Mutagenesis by alanine scan demonstrated that the motifs for primase and for nucleotide binding present in the protein are essential for RepA activity. The replication initiation functions of RepA are replicon specific. The replication initiation proteins DnaA, DnaG, and DnaB of the host are unable to promote origin replication in the presence of mutant RepA proteins that carry single residue exchanges in these motifs. The proposed origins of the known related hairpin prophages PY54, N15, and PKO2 are all located toward the 3′ end of the corresponding
repA
genes, where several structure elements are conserved. Origin function depends on the integrity of these elements.