bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasmid Partition System of the P1parFamily from the pWR100 Virulence Plasmid ofShigella flexneri
Authors: Sergueev Kirill , Dabrazhynetskaya Alena , Austin Stuart 
Published: May 2005

ABSTRACTP1parfamily members promote the active segregation of a variety of plasmids and plasmid prophages in gram-negative bacteria. Each has genes for ParA and ParB proteins, followed by aparSpartition site. The large virulence plasmid pWR100 ofShigella flexnericontains a new P1parfamily member: pWR100par. Although typicalparAandparBgenes are present, the putative pWR100parSsite is atypical in sequence and organization. However, pWR100parSpromoted accurate plasmid partition inEscherichia coliwhen the pWR100 Par proteins were supplied. Unique BoxB hexamer motifs withinparSdefine species specificities among previously described family members. Although substantially different from P1parSfrom the P1 plasmid prophage ofE. coli, pWR100parShas the same BoxB sequence. As predicted, the species specificity of the two types proved identical. They also shared partition-mediated incompatibility, consistent with the proposed mechanistic link between incompatibility and species specificity. Among several informative sequence differences between pWR100parSand P1parSis the presence of a 21-bp insert at the center of the pWR100parSsite. Deletion of this insert left much of theparSactivity intact. Tolerance of central inserts with integral numbers of helical DNA turns reflects the critical topology of these sites, which are bent by binding the host IHF protein.
A Novel 3-Deoxy-d-manno-Octulosonic Acid (Kdo) Hydrolase That Removes the Outer Kdo Sugar ofHelicobacter pyloriLipopolysaccharide
Authors: Stead Christopher , Tran An , Ferguson Donald , McGrath Sara , Cotter Robert , Trent Stephen 
Published: May 2005

ABSTRACTThe lipid A domain anchors lipopolysaccharide (LPS) to the outer membrane and is typically a disaccharide of glucosamine that is both acylated and phosphorylated. The core and O-antigen carbohydrate domains are linked to the lipid A moiety through the eight-carbon sugar 3-deoxy-d-manno-octulosonic acid known as Kdo.Helicobacter pyloriLPS has been characterized as having a single Kdo residue attached to lipid A, predicting in vivo a monofunctional Kdo transferase (WaaA). However, using an in vitro assay system we demonstrate thatH. pyloriWaaA is a bifunctional enzyme transferring two Kdo sugars to the tetra-acylated lipid A precursor lipid IVA. In the present work we report the discovery of a Kdo hydrolase in membranes ofH. pyloricapable of removing the outer Kdo sugar from Kdo2-lipid A. Enzymatic removal of the Kdo group was dependent upon prior removal of the 1-phosphate group from the lipid A domain, and mass spectrometric analysis of the reaction product confirmed the enzymatic removal of a single Kdo residue by the Kdo-trimming enzyme. This is the first characterization of a Kdo hydrolase involved in the modification of gram-negative bacterial LPS.
The RssAB Two-Component Signal Transduction System in
Serratia marcescens
Regulates Swarming Motility and Cell Envelope Architecture in Response to Exogenous Saturated Fatty Acids
Authors: Lai Hsin-Chih , Soo Po-Chi , Wei Jun-Rong , Yi Wen-Ching , Liaw Shwu-Jen , Horng Yu-Tze , Lin Shi-Ming , Ho Shen-Wu , Swift Simon , Williams Paul 
Published: May 2005

ABSTRACT

Serratia marcescens
swarms at 30°C but not at 37°C on a nutrient-rich (LB) agar surface. Mini-Tn
5
mutagenesis of
S. marcescens
CH-1 yielded a mutant (WC100) that swarms not only vigorously at 37°C but also earlier and faster than the parent strain swarms at 30°C. Analysis of this mutant revealed that the transposon was inserted into a gene (
rssA
) predicted to encode a bacterial two-component signal transduction sensor kinase, upstream of which a potential response regulator gene (
rssB
) was located.
rssA
and
rssB
insertion-deletion mutants were constructed through homologous recombination, and the two mutants exhibited similar swarming phenotypes on LB swarming agar, in which swarming not only occurred at 37°C but also initiated at a lower cell density, on a surface with a higher agar concentration, and more rapidly than the swarming of the parent strain at 30°C. Both mutants also exhibited increased hemolysin activity and altered cell surface topologies compared with the parent CH-1 strain. Temperature and certain saturated fatty acids (SFAs) were found to negatively regulate
S. marcescens
swarming via the action of RssA-RssB. Analysis of the fatty acid profiles of the parent and the
rssA
and
rssB
mutants grown at 30°C or 37°C and under different nutrition conditions revealed a relationship between cellular fatty acid composition and swarming phenotypes. The cellular fatty acid profile was also observed to be affected by RssA and RssB. SFA-dependent inhibition of swarming was also observed in
Proteus mirabilis
, suggesting that either SFAs per se or the modulation of cellular fatty acid composition and hence homeostasis of membrane fluidity may be a conserved mechanism for regulating swarming motility in gram-negative bacteria.
CrgA Is an Inducible LysR-Type Regulator of
Neisseria meningitidis
, Acting both as a Repressor and as an Activator of Gene Transcription
Authors: Ieva Raffaele , Alaimo Cristina , Delany Isabel , Spohn Gunther , Rappuoli Rino , Scarlato Vincenzo 
Published: May 2005

ABSTRACT

The
crgA
gene of
Neisseria meningitidis
, which codes for a LysR-type regulator, is divergently oriented with respect to the
mdaB
gene, which codes for a hypothetical NADPH-quinone oxidoreductase. Transcriptional studies of the intergenic region between
crgA
and
mdaB
showed that two overlapping and divergent promoters, P

crgA

and P

mdaB

, control transcription of these genes. Deletion of the
crgA
gene led to a strong increase in transcription from the P

crgA

promoter and a concomitant strong decrease in transcription from the P

mdaB

promoter, indicating that CrgA acts both as an autorepressor of transcription at its own promoter and as an activator of transcription at the
mdaB
promoter. Addition of α-methylene-γ-butyrolactone (MBL), an inducer of NADPH-quinone oxidoreductase, to wild-type
N. meningitidis
cells specifically resulted in further activation of transcription of the P

mdaB

promoter and more repression of transcription of the P

crgA

promoter. No such regulation was observed when MBL was added to
crgA
-deficient cells, indicating that the transcriptional response to MBL is CrgA mediated. Under the same experimental conditions, no regulation of transcription by either CrgA or MBL was detected at the pilus and capsule genes. The role of CrgA in the regulation of gene expression during the infectious cycle of
N. meningitidis
is discussed.
Role of
mutS
and
mutL
Genes in Hypermutability and Recombination in
Staphylococcus aureus
Authors: Prunier Anne-Laure , Leclercq Roland 
Published: May 2005

ABSTRACT

The mutator phenotype has been linked in several bacterial genera to a defect in the methyl-mismatch repair system, in which the major components are MutS and MutL. This system is involved both in mismatch repair and in prevention of recombination between homeologous fragments in
Escherichia coli
and has been shown to play an important role in the adaptation of bacterial populations in changing and stressful environments. In this report we describe the molecular analysis of the
mutS
and
mutL
genes of
Staphylococcus aureus
. A genetic analysis of the
mutSL
region was performed in
S. aureus
RN4220. Reverse transcriptase PCR experiments confirmed the operon structure already reported in other gram-positive organisms. Insertional inactivation of
mutS
and
mutL
genes and complementation showed the role of both genes in hypermutability in this species. We also designed an in vitro model to study the role of MutS and MutL in homeologous recombination in
S. aureus
. For this purpose, we constructed a bank of
S. aureus
RN4220 and
mutS
and
mutL
mutants containing the integrative thermosensitive vector pBT1 in which fragments with various levels of identity (74% to 100%) to the
S. aureus sodA
gene were cloned. MutS and MutL proteins seemed to have a limited effect on the control of homeologous recombination. Sequence of
mutS
and
mutL
genes was analyzed in 11 hypermutable
S. aureus
clinical isolates. In four of five isolates with mutated or deleted
mutS
or
mutL
genes, a relationship between alterations and mutator phenotypes could be established by negative complementation of the
mutS
or
mutL
mutants.
YojI ofEscherichia coliFunctions as a Microcin J25 Efflux Pump
Authors: Delgado Mónica A. , Vincent Paula A. , Farías Ricardo N. , Salomón Raúl A. 
Published: May 2005

ABSTRACTIn the present study, we showed thatyojI, anEscherichia coliopen reading frame with an unknown function, mediates resistance to the peptide antibiotic microcin J25 when it is expressed from a multicopy vector. Disruption of the single chromosomal copy ofyojIincreased sensitivity of cells to microcin J25. The YojI protein was previously assumed to be an ATP-binding-cassette-type exporter on the basis of sequence similarities. We demonstrate that YojI is capable of pumping out microcin molecules. Thus, one obvious explanation for the protective effect against microcin J25 is that YojI action keeps the intracellular concentration of the peptide below a toxic level. The outer membrane protein TolC in addition to YojI is required for export of microcin J25 out of the cell. Microcin J25 is thus the first known substrate for YojI.
Agrobacterium tumefaciensVirB9, an Outer-Membrane-Associated Component of a Type IV Secretion System, Regulates Substrate Selection and T-Pilus Biogenesis
Authors: Jakubowski Simon J. , Cascales Eric , Krishnamoorthy Vidhya , Christie Peter J. 
Published: May 2005

ABSTRACTAgrobacterium tumefacienstranslocates DNA and protein substrates between cells via a type IV secretion system (T4SS) whose channel subunits include the VirD4 coupling protein, VirB11 ATPase, VirB6, VirB8, VirB2, and VirB9. In this study, we used linker insertion mutagenesis to characterize the contribution of the outer-membrane-associated VirB9 to assembly and function of the VirB/D4 T4SS. Twenty-five dipeptide insertion mutations were classified as permissive for intercellular substrate transfer (Tra+), completely transfer defective (Tra−), or substrate discriminating, e.g., selectively permissive for transfer only of the oncogenic transfer DNA and the VirE2 protein substrates or of a mobilizable IncQ plasmid substrate. Mutations inhibiting transfer of DNA substrates did not affect formation of close contacts of the substrate with inner membrane channel subunits but blocked formation of contacts with the VirB2 and VirB9 channel subunits, which is indicative of a defect in assembly or function of the distal portion of the secretion channel. Several mutations in the N- and C-terminal regions disrupted VirB9 complex formation with the outer-membrane-associated lipoprotein VirB7 or the inner membrane energy sensor VirB10. Several VirB9.i2-producing Tra+strains failed to elaborate T pilus at detectable levels (Pil−), and three such Tra+Pil−mutant strains were rendered Tra−upon deletion ofvirB2, indicating that the cellular form of pilin protein is essential for substrate translocation. Our findings, together with computer-based analyses, support a model in which distinct domains of VirB9 contribute to substrate selection and translocation, establishment of channel subunit contacts, and T-pilus biogenesis.
Identification of a 521-Kilodalton Protein (Gli521) Involved in Force Generation or Force Transmission for
Mycoplasma mobile
Gliding
Authors: Seto Shintaro , Uenoyama Atsuko , Miyata Makoto 
Published: May 2005

ABSTRACT

Several mycoplasma species are known to glide on solid surfaces such as glass in the direction of the membrane protrusion, but the mechanism underlying this movement is unknown. To identify a novel protein involved in gliding, we raised monoclonal antibodies against a detergent-insoluble protein fraction of
Mycoplasma mobile
, the fastest glider, and screened the antibodies for inhibitory effects on gliding. Five monoclonal antibodies stopped the movement of gliding mycoplasmas, keeping them on the glass surface, and all of them recognized a large protein in immunoblotting. This protein, named Gli521, is composed of 4,738 amino acids, has a predicted molecular mass of 520,559 Da, and is coded downstream of a gene for another gliding protein, Gli349, which is known to be responsible for glass binding during gliding. Edman degradation analysis indicated that the N-terminal region is processed at the peptide bond between the amino acid residues at positions 43 and 44. Analysis of gliding mutants isolated previously revealed that the Gli521 protein is missing in a nonbinding mutant, m9, where the
gli521
gene is truncated by a nonsense mutation at the codon for the amino acid at position 1170. Immunofluorescence and immunoelectron microscopy indicated that Gli521 localizes all around the base of the membrane protrusion, at the “neck,” as previously observed for Gli349. Analysis of the inhibitory effects of the anti-Gli521 antibody on gliding motility revealed that this protein is responsible for force generation or force transmission, a role distinct from that of Gli349, and also suggested conformational changes of Gli349 and Gli521 during gliding.
Structural and Functional Divergence of MutS2 from Bacterial MutS1 and Eukaryotic MSH4-MSH5 Homologs
Authors: Kang Josephine , Huang Shuyan , Blaser Martin J. 
Published: May 2005

ABSTRACTMutS homologs, identified in nearly all bacteria and eukaryotes, include the bacterial proteins MutS1 and MutS2 and the eukaryotic MutS homologs 1 to 7, and they often are involved in recognition and repair of mismatched bases and small insertion/deletions, thereby limiting illegitimate recombination and spontaneous mutation. To explore the relationship of MutS2 to other MutS homologs, we examined conserved protein domains. Fundamental differences in structure between MutS2 and other MutS homologs suggest that MutS1 and MutS2 diverged early during evolution, with all eukaryotic homologs arising from a MutS1 ancestor. Data from MutS1 crystal structures, biochemical results from MutS2 analyses, and our phylogenetic studies suggest that MutS2 has functions distinct from other members of the MutS family. AmutS2mutant was constructed inHelicobacter pylori, which lacksmutS1and mismatch repair genesmutLandmutH. We show that MutS2 plays no role in mismatch or recombinational repair or deletion between direct DNA repeats. In contrast, MutS2 plays a significant role in limiting intergenomic recombination across a range of donor DNA tested. This phenotypic analysis is consistent with the phylogenetic and biochemical data suggesting that MutS1 and MutS2 have divergent functions.
Comparative Analysis of Differentially Expressed Genes in
Shewanella oneidensis
MR-1 following Exposure to UVC, UVB, and UVA Radiation
Authors: Qiu Xiaoyun , Sundin George W. , Wu Liyou , Zhou Jizhong , Tiedje James M. 
Published: May 2005

ABSTRACT

We previously reported that
Shewanella oneidensis
MR-1 is highly sensitive to UVC (254 nm), UVB (290 to 320 nm), and UVA (320 to 400 nm). Here we delineated the cellular response of MR-1 to UV radiation damage by analyzing the transcriptional profile during a 1-h recovering period after UVC, UVB, and UVA exposure at a dose that yields about a 20% survival rate. Although the SOS response was observed with all three treatments, the induction was more robust in response to short-wavelength UV radiation (UVB and UVC). Similarly, more prophage-related genes were induced by short-wavelength UV radiation. MR-1 showed an active detoxification mechanism in response to UVA, which included the induction of antioxidant enzymes and iron-sequestering proteins to scavenge reactive oxygen species. In addition, a great number of genes encoding multidrug and heavy metal efflux pumps were induced following UVA irradiation. Our data suggested that activation of prophages appears the major lethal factor in MR-1 following UVC or UVB irradiation, whereas oxidative damage contributes greatly to the high UVA sensitivity in MR-1.
Developmental-Stage-Specific Assembly of ParB Complexes inStreptomyces coelicolorHyphae
Authors: Jakimowicz Dagmara , Gust Bertolt , Zakrzewska-Czerwinska Jolanta , Chater Keith F. 
Published: May 2005

ABSTRACTInStreptomyces coelicolorParB is required for accurate chromosome partitioning during sporulation. Using a functional ParB-enhanced green fluorescent protein fusion, we observed bright tip-associated foci and other weaker, irregular foci inS. coelicolorvegetative hyphae. In contrast, in aerial hyphae regularly spaced bright foci accompanied sporulation-associated chromosome condensation and septation.
Bacteriophage Mu Targets the Trinucleotide Sequence CGG
Authors: Manna Dipankar , Deng Shuang , Breier Adam M. , Higgins N. Patrick 
Published: May 2005

ABSTRACT
Target specificity for bacteriophage Mu was studied using a new phage derivative that enabled cloning of Mu-host junctions from phage DNA. Insertions distributed throughout the chromosome showed no orientation bias with respect to transcription or replication polarity. Genes with a high frequency of the triplet CGG were preferred targets.
Transcriptome Analysis of the Progressive Adaptation of
Lactococcus lactis
to Carbon Starvation
Authors: Redon Emma , Loubiere Pascal , Cocaign-Bousquet Muriel 
Published: May 2005

ABSTRACT

Adaptation of
Lactococcus lactis
towards progressive carbon starvation is mediated by three different types of transcriptomic responses: (i) global responses, i.e., general decreases of functions linked to bacterial growth and lack of induction of the general stress response; (ii) specific responses functionally related to glucose exhaustion, i.e., underexpression of central metabolism genes, induction of alternative sugar transport and metabolism, and induction of the arginine deiminase pathway; and (iii) other responses never described previously during carbon starvation.
New internationalism
Authors: Mohan Brij 
Published: May 2005

English Globalization and its many faces have essentially changed the content and character of inter- and intra-societal relationships. A new kind of social work will have to embrace universalization of values, knowledge and skills that promote inclusive world citizenship and global coexistence. French La mondialisation et ses multiples visages ont essentiellement changé le contenu et le caractère des relations inter- et intra-sociétales. Une nouvelle forme de travail social devra se fonder sur des valeurs, des connaissances et des habiletés universelles qui mettent de l'avant des notions de citoyenneté mondiale inclusive et de coexistence globale. Spanish La globalización y sus muchas facetas han cambiado esencialmente el contenido y el carácter de las relaciones inter e intrasociales. Un nuevo tipo de trabajo social tendrá que abrazar la universalización de los valores, el conocimiento y las destrezas que promuevan una ciudadanía mundial y una coexistencia global inclusivas.
The role of nonprofit organizations in the delivery of family services in 11 EU member and applicant states
Authors: Appleton Louise 
Published: May 2005

English This article explores how family services are delivered across EU member and applicant states through nonprofit organizations. Historical, political, cultural and financial factors are shown to impact upon the role of NPOs at both the national and sub-national levels, which may determine the efficacy of measures to increase nonprofit sector involvement in policy implementation. French Cet article explore les faµons par lesquelles les organismes à but non lucratif desservent les familles dans les états membres de l'Union européenne et dans les pays requérants. La recherche démontre que des facteurs historiques, politiques, culturels et financiers ont un impact sur le rôle des organismes à but non lucratif tant au niveau national que régional. Ces facteurs peuvent déterminer l'efficacité des mesures utilisées pour hausser l'implication du secteur des organismes à but non lucratif dans l'implémentation des politiques. Spanish Este trabajo explora la manera en que son otorgados los servicios familiares, en diferentes estados de la Unión Europea, a través de las organizaciones altruistas. Se muestra cómo los factores históricos, políticos, culturales y financieros influyen sobre el papel que cumplen estas organizaciones tanto a nivel nacional como a nivel local; lo cual puede determinar la eficacia de las medidas para incrementar la participación del sector altruista en la implementación de políticas.
Marital conflict and social support of Korean immigrants in the United States
Authors: Lee Eunju 
Published: May 2005

English The goal is to study the relationship between marital conflict and social support in Korean immigrants. Both the cultural values of male dominance and life stress are major factors in marital conflict. Social support has an important role in reducing its incidence. French Le but de cette étude est d'explorer les relations entre les conflits conjugaux et le soutien social parmi les immigrants coréens. Les valeurs culturelles de dominance masculine et de stress de la vie constituent des facteurs majeurs dans les conflits de couples. Le soutien social joue un rôle important dans la'réduction d'incidences de conflits conjugaux. Spanish La meta es estudiar la relación entre el conflicto matrimonial y el apoyo social en los inmigrantes Coreanos. Tanto los valores culturales de dominación hacia las mujeres como el estrés cotidiano son factores importantes en el conflicto matrimonial. El apoyo social juega un papel importante en la reducción de la incidencia del conflicto matrimonial.
Disseminated intravascular coagulation associated with acute hemoglobinemia or hemoglobinuria following Rho(D) immune globulin intravenous administration for immune thrombocytopenic purpura
Authors: Gaines Ann Reed 
Published: May 2005

Abstract
The Food and Drug Administration (FDA) licensed Rho(D) immune globulin intravenous (anti-D IGIV) on March 24, 1995, for treatment of immune thrombocytopenic purpura (ITP). A previous review described data on 15 patients who experienced acute hemoglobinemia or hemoglobinuria following anti-D IGIV administration for ITP or secondary thrombocytopenia. Eleven of those patients also experienced clinically compromising anemia, transfusion with packed red blood cells, renal insufficiency, dialysis, or death. That review suggested that patients receiving anti-D IGIV be monitored for those and other potential complications of hemoglobinemia, particularly disseminated intravascular coagulation (DIC). Through November 30, 2004, the FDA received 6 reports of DIC associated with “acute hemolysis” (or similar terms), 5 of which involved fatalities. The attending or consulting physicians assessed that acute hemolysis or DIC caused or contributed to each death. This review presents the first case series of DIC associated with acute hemoglobinemia or hemoglobinuria following anti-D IGIV administration for ITP. The purpose of this review is to increase awareness among physicians and other health care professionals that DIC may be a rare but potentially severe complication of anti-D IGIV treatment. Increased awareness of DIC as a diagnostic possibility may enable prompt recognition and medical intervention in affected patients.