Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| inhibition of plant-pathogenic bacteria by short synthetic cecropin a-melittin hybrid peptides. | short peptides of 11 residues were synthesized and tested against the economically important plant pathogenic bacteria erwinia amylovora, pseudomonas syringae, and xanthomonas vesicatoria and compared to the previously described peptide pep3 (wklfkkilkvl-nh(2)). the antimicrobial activity of pep3 and 22 analogues was evaluated in terms of the mic and the 50% effective dose (ed(50)) for growth. peptide cytotoxicity against human red blood cells and peptide stability toward protease degradation we ... | 2006 | 16672470 |
| wrba from escherichia coli and archaeoglobus fulgidus is an nad(p)h:quinone oxidoreductase. | wrba (tryptophan [w] repressor-binding protein) was discovered in escherichia coli, where it was proposed to play a role in regulation of the tryptophan operon; however, this has been put in question, leaving the function unknown. here we report a phylogenetic analysis of 30 sequences which indicated that wrba is the prototype of a distinct family of flavoproteins which exists in a diversity of cell types across all three domains of life and includes documented nad(p)h:quinone oxidoreductases (n ... | 2006 | 16672604 |
| direct visualization of red fluorescent lipoproteins indicates conservation of the membrane sorting rules in the family enterobacteriaceae. | chimeras created by fusing the monomeric red fluorescent protein (rfp) to a bacterial lipoprotein signal peptide (liporfps) were visualized in the cell envelope by epifluorescence microscopy. plasmolysis of the bacteria separated the inner and outer membranes, allowing the specific subcellular localization of liporfps to be determined in situ. when equipped with the canonical inner membrane lipoprotein retention signal cdsr, liporfp was located in the inner membrane in escherichia coli, whereas ... | 2006 | 16672606 |
| application of comparative phylogenomics to study the evolution of yersinia enterocolitica and to identify genetic differences relating to pathogenicity. | yersinia enterocolitica, an important cause of human gastroenteritis generally caused by the consumption of livestock, has traditionally been categorized into three groups with respect to pathogenicity, i.e., nonpathogenic (biotype 1a), low pathogenicity (biotypes 2 to 5), and highly pathogenic (biotype 1b). however, genetic differences that explain variation in pathogenesis and whether different biotypes are associated with specific nonhuman hosts are largely unknown. in this study, we applied ... | 2006 | 16672618 |
| detecting uber-operons in prokaryotic genomes. | we present a study on computational identification of uber-operons in a prokaryotic genome, each of which represents a group of operons that are evolutionarily or functionally associated through operons in other (reference) genomes. uber-operons represent a rich set of footprints of operon evolution, whose full utilization could lead to new and more powerful tools for elucidation of biological pathways and networks than what operons have provided, and a better understanding of prokaryotic genome ... | 2006 | 16682449 |
| comparative genomics reveals what makes an enterobacterial plant pathogen. | the bacterial family enterobacteriaceae contains some of the most devastating human and animal pathogens, including escherichia coli, salmonella enterica and species of yersinia and shigella. these are among the best-studied of any organisms, yet there is much to be learned about the nature and evolution of interactions with their hosts and with the wider environment. comparative and functional genomics have fundamentally improved our understanding of their modes of adaptation to different ecolo ... | 2006 | 16704357 |
| evolution of immunity and host chromosome integration site of p2-like coliphages. | the amount and distribution of variation in the genomic region containing the genes in the lytic-lysogenic genetic switch and the sequence that determines the integration site into the host chromosome were analyzed for 38 p2-like phages from escherichia coli. the genetic switch consists of two convergent mutually exclusive promoters, pe and pc, and two repressors, c and cox. the immunity repressor c blocks the early pe promoter, leading to the establishment of lysogeny. the cox repressor blocks ... | 2006 | 16707684 |
| structural and functional characterization of three polyketide synthase gene clusters in bacillus amyloliquefaciens fzb 42. | although bacterial polyketides are of considerable biomedical interest, the molecular biology of polyketide biosynthesis in bacillus spp., one of the richest bacterial sources of bioactive natural products, remains largely unexplored. here we assign for the first time complete polyketide synthase (pks) gene clusters to bacillus antibiotics. three giant modular pks systems of the trans-acyltransferase type were identified in bacillus amyloliquefaciens fzb 42. one of them, pks1, is an ortholog of ... | 2006 | 16707694 |
| altering glucosinolate profiles modulates disease resistance in plants. | plant diseases are major contributing factors for crop loss in agriculture. here, we show that arabidopsis plants with high levels of novel glucosinolates (gss) as a result of the introduction of single cyp79 genes exhibit altered disease resistance. arabidopsis expressing cyp79d2 from cassava accumulated aliphatic isopropyl and methylpropyl gs, and showed enhanced resistance against the bacterial soft-rot pathogen erwinia carotovora, whereas arabidopsis expressing the sorghum cyp79a1 or over-ex ... | 2006 | 16709192 |
| outer membrane protein genes and their small non-coding rna regulator genes in photorhabdus luminescens. | three major outer membrane protein genes of escherichia coli, ompf, ompc, and ompa respond to stress factors. transcripts from these genes are regulated by the small non-coding rnas micf, micc, and mica, respectively. here we examine photorhabdus luminescens, an organism that has a different habitat from e. coli for outer membrane protein genes and their regulatory rna genes. | 2006 | 16716220 |
| biology of pseudomonas stutzeri. | pseudomonas stutzeri is a nonfluorescent denitrifying bacterium widely distributed in the environment, and it has also been isolated as an opportunistic pathogen from humans. over the past 15 years, much progress has been made in elucidating the taxonomy of this diverse taxonomical group, demonstrating the clonality of its populations. the species has received much attention because of its particular metabolic properties: it has been proposed as a model organism for denitrification studies; many ... | 2006 | 16760312 |
| cooperative control of drosophila immune responses by the jnk and nf-kappab signaling pathways. | jun n-terminal kinase (jnk) signaling is a highly conserved pathway that controls both cytoskeletal remodeling and transcriptional regulation in response to a wide variety of signals. despite the importance of jnk in the mammalian immune response, and various suggestions of its importance in drosophila immunity, the actual contribution of jnk signaling in the drosophila immune response has been unclear. drosophila tak1 has been implicated in the nf-kappab/relish-mediated activation of antimicrob ... | 2006 | 16763552 |
| [effect of exogenous plasmid r68.45 on productive and lisogenic development of temperate bacteriophage zf40 erwinia carotovora]. | the erwinia carotoerora strains bearing exogenous plasmid r68.45 have been obtained by means of transconjugation. dynamics and frequency characteristics of plasmid transfer to erwinia cells have been studied. plasmid-phage interrelations have been studied for the first time in e. carotovora. it has been established that the presence of exogenous plasmid r68.45 affects essentially the culture growth parameters and lisogenization of e. carotovora by the wild phage zf40 and its clear-mutants. the p ... | 2006 | 16786628 |
| genomic analysis of carbon source metabolism of shewanella oneidensis mr-1: predictions versus experiments. | genomic sequences have been used to find the genetic foundation for carbon source metabolism in shewanella oneidensis mr-1. annotated s. oneidensis mr-1 gene products were examined for their sequence similarity to enzymes participating in pathways for utilization of carbon and energy as described in the biocyc database (http://www.biocyc.org/) or in the primary literature. a picture emerges that relegates five- and six-carbon sugars to minor roles as carbon sources, whereas multiple pathways for ... | 2006 | 16788168 |
| erwinia carotovora subspecies produce duplicate variants of expr, luxr homologs that activate rsma transcription but differ in their interactions with n-acylhomoserine lactone signals. | the n-acylhomoserine lactone (ahl) signaling system comprises a producing system that includes acylhomoserine synthase (ahli, a luxi homolog) and a receptor, generally a luxr homolog. ahl controls exoprotein production in erwinia carotovora and consequently the virulence for plants. in previous studies we showed that expr, a luxr homolog, is an ahl receptor and that it activates transcription of rsma, the gene encoding an rna binding protein which is a global negative regulator of exoproteins an ... | 2006 | 16788181 |
| bacteriocin-like substance inhibits potato soft rot caused by erwinia carotovora. | soft rot is a major problem encountered in potatoes during postharvest storage. the soft rot bacterium erwinia carotovora was inhibited by a novel bacteriocin-like substance (bls) produced by bacillus licheniformis p40. the bls caused a bactericidal effect on e. carotovora cells at 30 microg ml(-1). transmission electron microscopy showed that bls-treated cells presented wrinkled bacterial surfaces and shrinkage of the whole cell, indicating plasmolysis. erwinia carotovora cells treated with bls ... | 2006 | 16788721 |
| prevalence of local immune response against oral infection in a drosophila/pseudomonas infection model. | pathogens have developed multiple strategies that allow them to exploit host resources and resist the immune response. to study how drosophila flies deal with infectious diseases in a natural context, we investigated the interactions between drosophila and a newly identified entomopathogen, pseudomonas entomophila. flies orally infected with p. entomophila rapidly succumb despite the induction of both local and systemic immune responses, indicating that this bacterium has developed specific stra ... | 2006 | 16789834 |
| cooperation of two distinct expr regulators controls quorum sensing specificity and virulence in the plant pathogen erwinia carotovora. | quorum sensing, the population density-dependent regulation mediated by n-acylhomoserine lactones (ahsl), is essential for the control of virulence in the plant pathogen erwinia carotovora ssp. carotovora (ecc). in erwinia carotovora ssp. the ahsl signal with an acyl chain of either 6 or 8 carbons is generated by an ahsl synthase, the expi gene product. this work demonstrates that the ahsl receptor, expr1, of ecc strain scc3193 has strict specificity for the cognate ahsl 3-oxo-c8-hsl. we have al ... | 2006 | 16796682 |
| molecular characterization of pantoea stewartii subsp. stewartii hrpy, a conserved response regulator of the hrp type iii secretion system, and its interaction with the hrps promoter. | pantoea stewartii subsp. stewartii is a bacterial pathogen of corn. its pathogenicity depends on the translocation of effector proteins into host cells by the hrp type iii secretion system. we previously showed by genetic analysis that the hrpx sensor kinase and the hrpy response regulator are at the head of a complex cascade of regulators controlling hrp/hrc secretion and wts effector genes. this cascade also includes the hrps response regulator and the hrpl alternative sigma factor. these regu ... | 2006 | 16816181 |
| prediction of csra-regulating small rnas in bacteria and their experimental verification in vibrio fischeri. | the role of small rnas as critical components of global regulatory networks has been highlighted by several recent studies. an important class of such small rnas is represented by csrb and csrc of escherichia coli, which control the activity of the global regulator csra. given the critical role played by csra in several bacterial species, an important problem is the identification of csra-regulating small rnas. in this paper, we develop a computer program (csrna_find) designed to locate potentia ... | 2006 | 16822857 |
| herbivore-induced resistance against microbial pathogens in arabidopsis. | caterpillars of the herbivore pieris rapae stimulate the production of jasmonic acid (ja) and ethylene (et) in arabidopsis (arabidopsis thaliana) and trigger a defense response that affects insect performance on systemic tissues. to investigate the spectrum of effectiveness of p. rapae-induced resistance, we examined the level of resistance against different pathogens. although the necrotrophic fungus alternaria brassicicola is sensitive to ja-dependent defenses, herbivore-induced resistance was ... | 2006 | 16829584 |
| restraining erwinia virulence by expression of n-acyl homoserine lactonase gene pro3a-aiia in bacillus thuringiensis subsp leesis. | to widen the biological control function of a genetically modified bacillus thuringiensis subsp leesis strain bmb-005, an acyl homoserine lactonase (ahl lactonase) gene aiia transcribed by the promoter of insecticidal crystal protein coding gene cry3a, was transformed into strain bmb-005. the amount of ahl lactonase protein produced by transformant bmb821a was 2.4-fold more than that produced by bmb-005. ahl-degradation assay showed that transformant bmb821a could degrade more ahls molecules tha ... | 2006 | 16838380 |
| n-acylhomoserine lactonase producing rhodococcus spp. with different ahl-degrading activities. | n-acylhomoserine lactones (ahls) are conserved signal molecules that control diverse biological activities in quorum sensing system of gram-negative bacteria. recently, several soil bacteria were found to degrade ahls, thereby interfering with the quorum sensing system. previously, rhodococcus erythropolis w2 was reported to degrade ahls by both oxido-reductase and ahl-acylase. in the present study, two ahl-utilizing bacteria, strains ls31 and pi33, were isolated and identified as the genus rhod ... | 2006 | 16842366 |
| bacterial conversations: talking, listening and eavesdropping. a nerc discussion meeting held at the royal society on 7 december 2005. | 2006 | 16849274 | |
| an essential complementary role of nf-kappab pathway to microbicidal oxidants in drosophila gut immunity. | in the drosophila gut, reactive oxygen species (ros)-dependent immunity is critical to host survival. this is in contrast to the nf-kappab pathway whose physiological function in the microbe-laden epithelia has yet to be convincingly demonstrated despite playing a critical role during systemic infections. we used a novel in vivo approach to reveal the physiological role of gut nf-kappab/antimicrobial peptide (amp) system, which has been 'masked' in the presence of the dominant intestinal ros-dep ... | 2006 | 16858400 |
| [functional organization of prophage and lysogeny in erwinia carotovora with participation of a temperate bacteriophage zf40]. | functional organization of a prophage of the temperate bacteriophage zf40 of erwinia carotovora subsp. carotovora which includes its immunity and inducibility as well as its effect on the host phenotype. it was established that the prophage zf40 forms several different states in e. carotovora which are distinguished by the indices of spontaneous and lysogenic induction. in contrast to other prophages, including the lambdoid ones, the prophage zf40 is capable to establish cytoplasmic overimmunity ... | 2006 | 16869142 |
| [characteristics of lysogenic induction of bacteriocins in thymine mutants of erwinia carotovora]. | peculiarities of lisogenic induction of bacteriocins in thymine-dependent mutants of erwinia carotovora subsp. carotovora have been studied. it was shown for the first time that availability of carotovoricins of two (and above) types characterized the defect polylysogeny of strains of different geographic origin. use of various methods of induction of thy--mutants or inducing agents of different nature leads to a selective accumulation of carotovoricins of certain types in the cell lysates. resu ... | 2006 | 16869143 |
| erwinia carotovora evf antagonizes the elimination of bacteria in the gut of drosophila larvae. | erwinia virulence factor (evf) has been identified in erwinia carotovora carotovora 15 (ecc15) as a virulence factor that promotes colonization of the drosophila larval gut and provokes the triggering of a systemic immune response. here we have analysed how evf promotes persistence and colonization of bacteria inside the larval gut. erwinia evf mutants do not persist in immune-deficient drosophila, indicating that evf does not act by counteracting immunity. the results indicated that evf is not ... | 2007 | 16879453 |
| global gene expression analysis of the heat shock response in the phytopathogen xylella fastidiosa. | xylella fastidiosa is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. although different strains have been studied, little is known about x. fastidiosa stress responses. one of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. to investigate x. fastidio ... | 2006 | 16885450 |
| two gaca-dependent small rnas modulate the quorum-sensing response in pseudomonas aeruginosa. | in pseudomonas aeruginosa, the gacs/gaca two-component system positively controls the quorum-sensing machinery and the expression of extracellular products via two small regulatory rnas, rsmy and rsmz. an rsmy rsmz double mutant and a gaca mutant were similarly impaired in the synthesis of the quorum-sensing signal n-butanoyl-homoserine lactone, the disulfide bond-forming enzyme dsba, and the exoproducts hydrogen cyanide, pyocyanin, elastase, chitinase (chic), and chitin-binding protein (cbpd). ... | 2006 | 16885472 |
| the drosophila inhibitor of apoptosis protein diap2 functions in innate immunity and is essential to resist gram-negative bacterial infection. | the founding member of the inhibitor of apoptosis protein (iap) family was originally identified as a cell death inhibitor. however, recent evidence suggests that iaps are multifunctional signaling devices that influence diverse biological processes. to investigate the in vivo function of drosophila melanogaster iap2, we have generated diap2 null alleles. diap2 mutant animals develop normally and are fully viable, suggesting that diap2 is dispensable for proper development. however, these animal ... | 2006 | 16894030 |
| [oligomerization of l-asparaginase from erwinia carotovora]. | bacterial l-asparaginases catalyzing hydrolysis of l-asparagine up to l-aspartate and ammonia, are used in medical practice for treatment of acute lymphoblastic leukemia. the long-term therapy with these preparations is accompanied by a number of side effects, which are attributed to glutaminase activity of l-asparaginase. substrate specificity and activity of l-asparaginases are directly associated with the process of enzyme oligomerization. it is active only in the tetrameric form as the activ ... | 2006 | 16898584 |
| gacs-dependent production of 2r, 3r-butanediol by pseudomonas chlororaphis o6 is a major determinant for eliciting systemic resistance against erwinia carotovora but not against pseudomonas syringae pv. tabaci in tobacco. | root colonization by a plant-beneficial rhizobacterium, pseudomonas chlororaphis o6, induces disease resistance in tobacco against leaf pathogens erwinia carotovora subsp. carotovora scc1, causing soft-rot, and pseudomonas syringae pv. tabaci, causing wildfire. in order to identify the bacterial determinants involved in induced systemic resistance against plant diseases, extracellular components produced by the bacterium were fractionated and purified. factors in the culture filtrate inducing sy ... | 2006 | 16903358 |
| genetic analysis of the requirement for flp-2, tadv, and rcpb in actinobacillus actinomycetemcomitans biofilm formation. | the tad locus of actinobacillus actinomycetemcomitans encodes a molecular transport system required for tenacious, nonspecific adherence to surfaces and formation of extremely strong biofilms. this locus is dedicated to the biogenesis of flp pili, which are required for colonization and virulence. we have previously shown that 11 of the 14 tad locus genes are required for adherence and flp pilus production. here, we present genetic and phylogenetic analyses of flp-2, tadv, and rcpb genes in biof ... | 2006 | 16923904 |
| transcriptional downregulator hexs controlling prodigiosin and serrawettin w1 biosynthesis in serratia marcescens. | serratia marcescens has been known as a temperature-dependent producer of two chemically different exolipids (red pigment prodigiosin and biosurfactant serrawettin w1) in parallel. during genetic investigation of such control mechanisms, mini-tn 5 insertional mutant tan1 overproducing these exolipids was isolated. the gene concerning such disregulation was identified as hexs by dna cloning followed by sequencing and homology analysis of the presumed product with 314 amino-acids. the product hexs ... | 2006 | 16924143 |
| bacterial elicitation and evasion of plant innate immunity. | recent research on plant responses to bacterial attack has identified extracellular and intracellular host receptors that recognize conserved pathogen-associated molecular patterns and more specialized virulence proteins, respectively. these findings have shed light on our understanding of the molecular mechanisms by which bacteria elicit host defences and how pathogens have evolved to evade or suppress these defences. | 2006 | 16936700 |
| effectiveness of two-sided uv-c treatments in inhibiting natural microflora and extending the shelf-life of minimally processed 'red oak leaf' lettuce. | the use of uv-c radiation treatments to inhibit the microbial growth and extend the shelf-life of minimally processed 'red oak leaf' lettuce was investigated. initially, uv-c resistance of 20 bacterial strains from different genera often associated with fresh produce (enterobacter, erwinia, escherichia, leuconostoc, pantoea, pseudomonas, rahnela, salmonella, serratia and yersinia) were tested in vitro. most of the bacterial strains were inhibited with the minimum dose (30 j m(-2)). erwinia carot ... | 2006 | 16943010 |
| interspecific transfer of bacterial endosymbionts between tsetse fly species: infection establishment and effect on host fitness. | tsetse flies (glossina spp.) can harbor up to three distinct species of endosymbiotic bacteria that exhibit unique modes of transmission and evolutionary histories with their host. two mutualist enterics, wigglesworthia and sodalis, are transmitted maternally to tsetse flies' intrauterine larvae. the third symbiont, from the genus wolbachia, parasitizes developing oocytes. in this study, we determined that sodalis isolates from several tsetse fly species are virtually identical based on a phylog ... | 2006 | 16950907 |
| tungsten transport protein a (wtpa) in pyrococcus furiosus: the first member of a new class of tungstate and molybdate transporters. | a novel tungstate and molybdate binding protein has been discovered from the hyperthermophilic archaeon pyrococcus furiosus. this tungstate transport protein a (wtpa) is part of a new abc transporter system selective for tungstate and molybdate. wtpa has very low sequence similarity with the earlier-characterized transport proteins moda for molybdate and tupa for tungstate. its structural gene is present in the genome of numerous archaea and some bacteria. the identification of this new tungstat ... | 2006 | 16952940 |
| nucleotide sequences and organization of the genes for carotovoricin (ctv) from erwinia carotovora indicate that ctv evolved from the same ancestor as salmonella typhi prophage. | carotovoricin er (ctver), which is produced by a plant soft rot disease causative agent, erwinia carotovora subsp. carotovora er, is a high-molecular-weight bacteriocin showing myoviridae phage-tail-like morphology with contractile sheath and plural tail fibers. we determined the complete nucleotide sequences of ctver genes on the e. carotovora er chromosome and report that ctver genes consist of lysis cassette, major and minor structural protein gene clusters. four promoters were identified. th ... | 2006 | 16960352 |
| genetic differences between blight-causing erwinia species with differing host specificities, identified by suppression subtractive hybridization. | pcr-based subtractive hybridization was used to isolate sequences from erwinia amylovora strain ea110, which is pathogenic on apples and pears, that were not present in three closely related strains with differing host specificities: e. amylovora mr1, which is pathogenic only on rubus spp.; erwinia pyrifoliae ep1/96, the causal agent of shoot blight of asian pears; and erwinia sp. strain ejp556, the causal agent of bacterial shoot blight of pear in japan. in total, six subtractive libraries were ... | 2006 | 16963554 |
| structural organization and functional properties of miniature dna insertion sequences in yersiniae. | ypals (yersinia palindromic sequences) are miniature dna insertions scattered along the chromosomes of yersiniae. the spread of these intergenic repeats likely occurred via transposition, as suggested by the presence of target site duplications at their termini and the identification of syntenic chromosomal regions which differ in the presence/absence of ypal dna among yersinia strains. ypals tend to be inserted closely downstream from the stop codon of flanking genes, and many ypal targets over ... | 2006 | 16963573 |
| diverse bacterial genomes encode an operon of two genes, one of which is an unusual class-i release factor that potentially recognizes atypical mrna signals other than normal stop codons. | while all codons that specify amino acids are universally recognized by trna molecules, codons signaling termination of translation are recognized by proteins known as class-i release factors (rf). in most eukaryotes and archaea a single rf accomplishes termination at all three stop codons. in most bacteria, there are two rfs with overlapping specificity, rf1 recognizes ua(a/g) and rf2 recognizes u(a/g)a. | 2006 | 16970810 |
| transcriptional analysis of the reca gene of streptococcus thermophilus. | reca is a highly conserved prokaryotic protein that not only plays several important roles connected to dna metabolism but also affects the cell response to various stress conditions. while reca is highly conserved, the mechanism of transcriptional regulation of its structural gene is less conserved. in escherichia coli the lexa protein acts as a reca repressor and is able, in response to dna damage, of reca-promoted self-cleavage, thus allowing reca transcription. the lexa paradigm, although co ... | 2006 | 16972988 |
| the cation-responsive protein nhar of escherichia coli activates pgaabcd transcription, required for production of the biofilm adhesin poly-beta-1,6-n-acetyl-d-glucosamine. | the pgaabcd operon of escherichia coli is required for production of the biofilm adhesin poly-beta-1,6-n-acetyl-d-glucosamine (pga). we establish here that nhar, a dna-binding protein of the lysr family of transcriptional regulators, activates transcription of this operon. disruption of the nhar gene decreased biofilm formation without affecting planktonic growth. pga production was undetectable in an nhar mutant strain. expression of a pgaa'-'lacz translational fusion was induced by nacl and al ... | 2006 | 16997959 |
| the rcs phosphorelay system is specific to enteric pathogens/commensals and activates ydei, a gene important for persistent salmonella infection of mice. | bacteria utilize phosphorelay systems to respond to environmental or intracellular stimuli. salmonella enterica encodes a four-step phosphorelay system that involves two sensor kinase proteins, rcsc and rcsd, and a response regulator, rcsb. the physiological stimulus for rcs phosphorelay activation is unknown; however, rcs-regulated genes can be induced in vitro by osmotic shock, low temperature and antimicrobial peptide exposure. in this report we investigate the role of the rcs pathway using p ... | 2006 | 17010160 |
| cloning, crystallization and preliminary x-ray study of xc1258, a cn-hydrolase superfamily protein from xanthomonas campestris. | cn-hydrolase superfamily proteins are involved in a wide variety of non-peptide carbon-nitrogen hydrolysis reactions, producing some important natural products such as auxin, biotin, precursors of antibiotics etc. these reactions all involve attack on a cyano or carbonyl carbon by a conserved novel catalytic triad glu-lys-cys through a thiol acylenzyme intermediate. however, classification into the cn-hydrolase superfamily based on sequence similarity alone is not straightforward and further str ... | 2006 | 17012795 |
| biological characterization of white line-inducing principle (wlip) produced by pseudomonas reactans ncppb1311. | the biological activities of the lipodepsipeptides (ldp) white line-inducing principle (wlip), produced by pseudomonas reactans ncppb1311, and tolaasin i, produced by r tolaasii ncppb2192, were compared. antimicrobial assays showed that both ldp inhibited the growth of fungi-including the cultivated mushrooms agaricus bisporus, lentinus edodes, and pleurotus spp.--chromista, and gram-positive bacteria. assays of the two ldp on blocks of agaricus bisporus showed their capacity to alter the mushro ... | 2006 | 17022175 |
| gata factors participate in tissue-specific immune responses in drosophila larvae. | drosophila responds to infection by producing a broad range of antimicrobial agents in the fat body and more restricted responses in tissues such as the gut, trachea, and malpighian tubules. the regulation of antimicrobial genes in larval fat depends on linked rel/nf-kappab and gata binding sites. serpent functions as the major gata transcription factor in the larval fat body. however, the transcriptional regulation of other tissue-specific responses is less well understood. here, we present evi ... | 2006 | 17032752 |
| production of soft rot resistant calla lily by expressing a ferredoxin-like protein gene (pflp) in transgenic plants. | an efficient protocol for the agrobacterium tumefaciens-mediated transformation of calla lily (zantedeschia elliottiana (w. wats.) engl. cultivar 'florex gold') is described. shoot basal discs were co-cultivated with a. tumefaciens c58c1 carrying a plasmid containing neomycin phosphotransferase (nptii) and plant ferredoxin-like protein (pflp) genes. after agrobacterium co-cultivation, the shoot basal discs were exposed to 100 mg l(-1) kanamycin for selection. twenty-eight out of 260 discs (10.8% ... | 2007 | 17033825 |
| [molecular identification and genetic diversity in konnyaku's soft rot bacteria]. | the soft rot bacteria erwinia are an important pathogens of konnyaku and other ornamental plants. thirty-three strains were isolated from soft-rotted konnyaku and other ornamental plants. according to the characteristics of pathogenicity and culture character on semi selective medium (crystal violet pectate, cvp), most of strains tested caused rotten symptom in tubers and stems of konnyaku, and characteristic deep cavities were formed on cvp. to amplify 16s-23s rdna intergenic transcribed spacer ... | 2006 | 17037047 |
| molecular evolution of the h-ns protein: interaction with hha-like proteins is restricted to enterobacteriaceae. | we show here that chromosomal hha-like genes are restricted to the enterobacteriaceae. the h-ns n-terminal domain of members of this family includes an unaltered seven-amino-acid sequence located between helixes 1 and 2, termed the hha signature, that contains key residues for h-ns-hha interaction. | 2007 | 17041043 |
| molecular evolution of the h-ns protein: interaction with hha-like proteins is restricted to enterobacteriaceae. | we show here that chromosomal hha-like genes are restricted to the enterobacteriaceae. the h-ns n-terminal domain of members of this family includes an unaltered seven-amino-acid sequence located between helixes 1 and 2, termed the hha signature, that contains key residues for h-ns-hha interaction. | 2007 | 17041043 |
| caspar, a suppressor of antibacterial immunity in drosophila. | drosophila has a primitive yet highly effective innate immune system. although the infection-dependent activation mechanisms of the drosophila immune system are well understood, its inhibitory regulation remains elusive. to find novel suppressors of the immune system, we performed a genetic screening for drosophila mutants with hyperactivated immune responses and isolated a loss-of-function mutant of caspar whose product is homologous to fas-associating factor 1 in mammals. interestingly, caspar ... | 2006 | 17050695 |
| early responsive to dehydration 15, a negative regulator of abscisic acid responses in arabidopsis. | early responsive to dehydration 15 (erd15) is rapidly induced in response to various abiotic and biotic stress stimuli in arabidopsis (arabidopsis thaliana). modulation of erd15 levels by overexpression or rnai silencing altered the responsiveness of the transgenic plants to the phytohormone abscisic acid (aba). overexpression of erd15 reduced the aba sensitivity of arabidopsis manifested in decreased drought tolerance and in impaired ability of the plants to increase their freezing tolerance in ... | 2006 | 17056758 |
| cloning and expression of the erwinia carotovora subsp. carotovora gene encoding the low-molecular-weight bacteriocin carocin s1. | the purpose of this study was to clone the carocin s1 gene and express it in a non-carocin-producing strain of erwinia carotovora. a mutant, th22-10, which produced a high-molecular-weight bacteriocin but not a low-molecular-weight bacteriocin, was obtained by tn5 insertional mutagenesis using h-rif-8-2 (a spontaneous rifampin-resistant mutant of erwinia carotovora subsp. carotovora 89-h-4). using thermal asymmetric interlaced pcr, the dna sequence from the tn5 insertion site and the dna sequenc ... | 2007 | 17071754 |
| the quorum-quenching metallo-gamma-lactonase from bacillus thuringiensis exhibits a leaving group thio effect. | lactone-hydrolyzing enzymes derived from some bacillus species are capable of disrupting quorum sensing in bacteria that use n-acyl-l-homoserine lactones (ahls) as intercellular signaling molecules. despite the promise of these quorum-quenching enzymes as therapeutic and anti-biofouling agents, the ring opening mechanism and the role of metal ions in catalysis have not been elucidated. labeling studies using (18)o, (2)h, and the ahl lactonase from bacillus thuringiensis implicate an addition-eli ... | 2006 | 17073460 |
| leaner and meaner genomes in escherichia coli. | a 'better' escherichia coli k-12 genome has recently been engineered in which about 15% of the genome has been removed by planned deletions. comparison with related bacterial genomes that have undergone a natural reduction in size suggests that there is plenty of scope for yet more deletions. | 2006 | 17076878 |
| genomic structure and phylogeny of the plant pathogen ralstonia solanacearum inferred from gene distribution analysis. | in the present study, we investigated the gene distribution among strains of the highly polymorphic plant pathogenic beta-proteobacterium ralstonia solanacearum, paying particular attention to the status of known or candidate pathogenicity genes. based on the use of comparative genomic hybridization on a pangenomic microarray for the gmi1000 reference strain, we have defined the conditions that allowed comparison of the repertoires of genes among a collection of 18 strains that are representativ ... | 2007 | 17085551 |
| genomic structure and phylogeny of the plant pathogen ralstonia solanacearum inferred from gene distribution analysis. | in the present study, we investigated the gene distribution among strains of the highly polymorphic plant pathogenic beta-proteobacterium ralstonia solanacearum, paying particular attention to the status of known or candidate pathogenicity genes. based on the use of comparative genomic hybridization on a pangenomic microarray for the gmi1000 reference strain, we have defined the conditions that allowed comparison of the repertoires of genes among a collection of 18 strains that are representativ ... | 2007 | 17085551 |
| synthesis of n-acyl homoserine lactone analogues reveals strong activators of sdia, the salmonella enterica serovar typhimurium luxr homologue. | n-acyl homoserine lactones (ahls) are molecules that are synthesized and detected by many gram-negative bacteria to monitor the population density, a phenomenon known as quorum sensing. salmonella enterica serovar typhimurium is an exceptional species since it does not synthesize its own ahls, while it does encode a luxr homologue, sdia, which enables this bacterium to detect ahls that are produced by other species. to obtain more information about the specificity of the ligand binding by sdia, ... | 2007 | 17085703 |
| synthesis of n-acyl homoserine lactone analogues reveals strong activators of sdia, the salmonella enterica serovar typhimurium luxr homologue. | n-acyl homoserine lactones (ahls) are molecules that are synthesized and detected by many gram-negative bacteria to monitor the population density, a phenomenon known as quorum sensing. salmonella enterica serovar typhimurium is an exceptional species since it does not synthesize its own ahls, while it does encode a luxr homologue, sdia, which enables this bacterium to detect ahls that are produced by other species. to obtain more information about the specificity of the ligand binding by sdia, ... | 2007 | 17085703 |
| autoinducer-2 of the fire blight pathogen erwinia amylovora and other plant-associated bacteria. | autoinducers are important for cellular communication of bacteria. the luxs gene has a central role in the synthesis of autoinducer-2 (ai-2). the gene was identified in a shotgun library of erwinia amylovora and primers designed for pcr amplification from bacterial dna. supernatants of several erwinia amylovora strains were assayed for ai-2 activity with a vibrio harveyi mutant and were positive. many other plant-associated bacteria also showed ai-2 activity such as erwinia pyrifoliae and erwini ... | 2007 | 17092294 |
| the thiol:disulfide oxidoreductase dsbb mediates the oxidizing effects of the toxic metalloid tellurite (teo32-) on the plasma membrane redox system of the facultative phototroph rhodobacter capsulatus. | the highly toxic oxyanion tellurite (teo3(2-)) is a well known pro-oxidant in mammalian and bacterial cells. this work examines the effects of tellurite on the redox state of the electron transport chain of the facultative phototroph rhodobacter capsulatus, in relation to the role of the thiol:disulfide oxidoreductase dsbb. under steady-state respiration, the addition of tellurite (2.5 mm) to membrane fragments generated an extrareduction of the cytochrome pool (c- and b-type hemes); further, in ... | 2007 | 17098900 |
| the thiol:disulfide oxidoreductase dsbb mediates the oxidizing effects of the toxic metalloid tellurite (teo32-) on the plasma membrane redox system of the facultative phototroph rhodobacter capsulatus. | the highly toxic oxyanion tellurite (teo3(2-)) is a well known pro-oxidant in mammalian and bacterial cells. this work examines the effects of tellurite on the redox state of the electron transport chain of the facultative phototroph rhodobacter capsulatus, in relation to the role of the thiol:disulfide oxidoreductase dsbb. under steady-state respiration, the addition of tellurite (2.5 mm) to membrane fragments generated an extrareduction of the cytochrome pool (c- and b-type hemes); further, in ... | 2007 | 17098900 |
| [introduction of transpozon tn9 to endogenic plasmids of erwinia carotovora during lysogenization of cells by coliphage p1]. | it has been shown that phage p1 of escherichia coli is able not only to lysogenize the cells of erwinia carotovora but also to be a source of transpozon tn9 for mutagenesis of cryptic plasmids of this important phytopathogen. since the amount of the introduction in one of plasmids pca25::tn9 is 3.8 kb, at an average, it is supposed that tn9 is inherited as a double tandem structure. a convenient method is offered for selecting bacterial clones carrying the plasmid pca25::tn9 which is based on co ... | 2006 | 17100326 |
| detection and characterization of bacteria from the potato rhizosphere degrading n-acyl-homoserine lactone. | quorum sensing plays a role in the regulation of soft rot diseases caused by the plant pathogenic bacterium pectobacterium carotovorum subsp. carotovorum. the signal molecules involved in quorum sensing in p. carotovorum subsp. carotovorum belong to the group of n-acyl homoserine lactones (ahls). in our study, we screened bacteria isolated from the potato rhizosphere for the ability to degrade ahls produced by p. carotovorum subsp. carotovorum. six isolates able to degrade ahls were selected for ... | 2006 | 17110970 |
| novel type iv secretion system involved in propagation of genomic islands. | type iv secretion systems (t4sss) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. a gene cluster of the haemophilus influenzae genomic island icehin1056 has been identified as a t4ss involved in the propagation of genomic islands. this t4ss is novel and evolutionarily distant from the previously described systems. mutation analysis showed that inactivation of key ge ... | 2007 | 17122343 |
| novel type iv secretion system involved in propagation of genomic islands. | type iv secretion systems (t4sss) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. a gene cluster of the haemophilus influenzae genomic island icehin1056 has been identified as a t4ss involved in the propagation of genomic islands. this t4ss is novel and evolutionarily distant from the previously described systems. mutation analysis showed that inactivation of key ge ... | 2007 | 17122343 |
| the presence of n-terminal secretion signal sequences leads to strong stimulation of the total expression levels of three tested medically important proteins during high-cell-density cultivations of escherichia coli. | genetic optimizations to achieve high-level production of three different proteins of medical importance for humans, granulocyte-macrophage colony-stimulating factor (gm-csf), interferon alpha 2b (ifn-alpha2b), and single-chain antibody variable fragment (scfv-phox), were investigated during high-cell-density cultivations of escherichia coli. all three proteins were poorly expressed when put under control of the strong pm/xyls promoter/regulator system, but high volumetric yields of gm-csf and s ... | 2007 | 17142370 |
| the presence of n-terminal secretion signal sequences leads to strong stimulation of the total expression levels of three tested medically important proteins during high-cell-density cultivations of escherichia coli. | genetic optimizations to achieve high-level production of three different proteins of medical importance for humans, granulocyte-macrophage colony-stimulating factor (gm-csf), interferon alpha 2b (ifn-alpha2b), and single-chain antibody variable fragment (scfv-phox), were investigated during high-cell-density cultivations of escherichia coli. all three proteins were poorly expressed when put under control of the strong pm/xyls promoter/regulator system, but high volumetric yields of gm-csf and s ... | 2007 | 17142370 |
| atptr3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in arabidopsis. | mutation in the wound-induced peptide transporter gene atptr3 (at5g46050) of arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. the heterologous expression in yeast was utilized to verify that the atptr3 protein transports di-and tripeptides. the t-dna insert in the atptr3-1 mutant in the arabidopsis ecotype c24 revealed two t-dna copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the atptr3 gene. an a ... | 2007 | 17143616 |
| substrate recognition by the hetero-octameric atp phosphoribosyltransferase from lactococcus lactis. | two families of atp phosphoribosyl transferases (atp-prt) join atp and 5-phosphoribosyl-1 pyrophosphate (prpp) in the first reaction of histidine biosynthesis. these consist of a homohexameric form found in all three kingdoms and a hetero-octameric form largely restricted to bacteria. hetero-octameric atp-prts consist of four hisgs catalytic subunits related to periplasmic binding proteins and four hisz regulatory subunits that resemble histidyl-trna synthetases. to clarify the relationship betw ... | 2006 | 17154531 |
| hpar, a putative marr family transcriptional regulator, is positively controlled by hrpg and hrpx and involved in the pathogenesis, hypersensitive response, and extracellular protease production of xanthomonas campestris pathovar campestris. | the marr family of transcriptional regulators of bacteria are involved in the regulation of many cellular processes, including pathogenesis. in this work, we have demonstrated genetically that hpar (hpa, hrp associated), which encodes a putative marr family regulator, is involved in the hypersensitive response (hr), pathogenicity, and extracellular protease production of the phytopathogenic bacterium xanthomonas campestris pathovar campestris. a mutation in hpar resulted in complete loss of viru ... | 2007 | 17158655 |
| hpar, a putative marr family transcriptional regulator, is positively controlled by hrpg and hrpx and involved in the pathogenesis, hypersensitive response, and extracellular protease production of xanthomonas campestris pathovar campestris. | the marr family of transcriptional regulators of bacteria are involved in the regulation of many cellular processes, including pathogenesis. in this work, we have demonstrated genetically that hpar (hpa, hrp associated), which encodes a putative marr family regulator, is involved in the hypersensitive response (hr), pathogenicity, and extracellular protease production of the phytopathogenic bacterium xanthomonas campestris pathovar campestris. a mutation in hpar resulted in complete loss of viru ... | 2007 | 17158655 |
| messing with bacterial quorum sensing. | quorum sensing is widely recognized as an efficient mechanism to regulate expression of specific genes responsible for communal behavior in bacteria. several bacterial phenotypes essential for the successful establishment of symbiotic, pathogenic, or commensal relationships with eukaryotic hosts, including motility, exopolysaccharide production, biofilm formation, and toxin production, are often regulated by quorum sensing. interestingly, eukaryotes produce quorum-sensing-interfering (qsi) compo ... | 2006 | 17158701 |
| how phosphotransferase system-related protein phosphorylation regulates carbohydrate metabolism in bacteria. | the phosphoenolpyruvate(pep):carbohydrate phosphotransferase system (pts) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. to carry out its catalytic function in sugar transport and phosphorylation, the pts uses pep as an energy source and phosphoryl donor. the phosphoryl group of pep is usually transferred via four distinct proteins (domains) to the transported sugar bo ... | 2006 | 17158705 |
| characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering. | sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ... | 2007 | 17163981 |
| characterization of the thermotoga maritima chemotaxis methylation system that lacks pentapeptide-dependent methyltransferase cher:mcp tethering. | sensory adaptation in bacterial chemotaxis is mediated by covalent modifications of specific glutamate and glutamine residues within the cytoplasmic domains of methyl-accepting chemotaxis proteins (mcps). in escherichia coli and salmonella enterica, efficient methylation of mcps depends on the localization of methyltransferase cher to mcp clusters through an interaction between the cher beta-subdomain and a pentapeptide sequence (nwetf or nwesf) at the c-terminus of the mcp. in vitro methylation ... | 2007 | 17163981 |
| high precision multi-genome scale reannotation of enzyme function by eficaz. | the functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. we have performed a reannotation of 245 genomes using an updated version of eficaz, a highly precise method for enzyme function prediction. | 2006 | 17166279 |
| the complete genome sequence and comparative genome analysis of the high pathogenicity yersinia enterocolitica strain 8081. | the human enteropathogen, yersinia enterocolitica, is a significant link in the range of yersinia pathologies extending from mild gastroenteritis to bubonic plague. comparison at the genomic level is a key step in our understanding of the genetic basis for this pathogenicity spectrum. here we report the genome of y. enterocolitica strain 8081 (serotype 0:8; biotype 1b) and extensive microarray data relating to the genetic diversity of the y. enterocolitica species. our analysis reveals that the ... | 2006 | 17173484 |
| global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of erwinia chrysanthemi 3937. | production of the plant hormone indole-3-acetic acid (iaa) is widespread among plant-associated microorganisms. the non-gall-forming phytopathogen erwinia chrysanthemi 3937 (strain ech3937) possesses iaam (asap16562) and iaah (asap16563) gene homologues. in this work, the null knockout iaam mutant strain ech138 was constructed. the iaa production by ech138 was reduced in m9 minimal medium supplemented with l-tryptophan. compared with wild-type ech3937, ech138 exhibited reduced ability to produce ... | 2007 | 17189441 |
| global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of erwinia chrysanthemi 3937. | production of the plant hormone indole-3-acetic acid (iaa) is widespread among plant-associated microorganisms. the non-gall-forming phytopathogen erwinia chrysanthemi 3937 (strain ech3937) possesses iaam (asap16562) and iaah (asap16563) gene homologues. in this work, the null knockout iaam mutant strain ech138 was constructed. the iaa production by ech138 was reduced in m9 minimal medium supplemented with l-tryptophan. compared with wild-type ech3937, ech138 exhibited reduced ability to produce ... | 2007 | 17189441 |
| low-abundance kutznerides from kutzneria sp. 744. | five new (5-9) and four known (1-4) kutznerides were isolated from the actinomycete kutzneria sp. 744. compounds 1-9 all consisted of a cyclohexadepsipeptide core with the general structure 2-(1-methylcyclopropyl)-d-glycine-(2s,3ar,8as)-6,7-dichloro-3a-hydroxy-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid-3-hydroxy-d-glutamic acid-o-methyl-l-serine-l-piperazic acid-(s)-2-hydroxy-3,3-dimethylbutyric acid. compounds 5, 6, and 8 contained erythro-3-hydroxy-d-glutamic acid, whereas 7 ... | 2006 | 17190458 |
| phytotoxicity and innate immune responses induced by nep1-like proteins. | we show that oomycete-derived nep1 (for necrosis and ethylene-inducing peptide1)-like proteins (nlps) trigger a comprehensive immune response in arabidopsis thaliana, comprising posttranslational activation of mitogen-activated protein kinase activity, deposition of callose, production of nitric oxide, reactive oxygen intermediates, ethylene, and the phytoalexin camalexin, as well as cell death. transcript profiling experiments revealed that nlps trigger extensive reprogramming of the arabidopsi ... | 2006 | 17194768 |
| diversity of the abundant pklc102/pagi-2 family of genomic islands in pseudomonas aeruginosa. | the known genomic islands of pseudomonas aeruginosa clone c strains are integrated into trna(lys) (pklc102) or trna(gly) (pagi-2 and pagi-3) genes and differ from their core genomes by distinctive tetranucleotide usage patterns. pklc102 and the related island papi-1 from p. aeruginosa pa14 were spontaneously mobilized from their host chromosomes at frequencies of 10% and 0.3%, making pklc102 the most mobile genomic island known with a copy number of 30 episomal circular pklc102 molecules per cel ... | 2007 | 17194795 |
| diversity of the abundant pklc102/pagi-2 family of genomic islands in pseudomonas aeruginosa. | the known genomic islands of pseudomonas aeruginosa clone c strains are integrated into trna(lys) (pklc102) or trna(gly) (pagi-2 and pagi-3) genes and differ from their core genomes by distinctive tetranucleotide usage patterns. pklc102 and the related island papi-1 from p. aeruginosa pa14 were spontaneously mobilized from their host chromosomes at frequencies of 10% and 0.3%, making pklc102 the most mobile genomic island known with a copy number of 30 episomal circular pklc102 molecules per cel ... | 2007 | 17194795 |
| functional analysis of arabidopsis wrky25 transcription factor in plant defense against pseudomonas syringae. | a common feature of plant defense responses is the transcriptional regulation of a large number of genes upon pathogen infection or treatment with pathogen elicitors. a large body of evidence suggests that plant wrky transcription factors are involved in plant defense including transcriptional regulation of plant host genes in response to pathogen infection. however, there is only limited information about the roles of specific wrky dna-binding transcription factors in plant defense. | 2007 | 17214894 |
| fusion of the genes for ahl-lactonase and s-layer protein in bacillus thuringiensis increases its ability to inhibit soft rot caused by erwinia carotovora. | two genes, ctc and ctc2, responsible for surface layer (s-layer) protein synthesis in bacillus thuringiensis ctc, were mutated and resulted in b. thuringiensis tr5. to synthesize and express the n-acyl-homoserine lactonase (ahl-lactonase) in the extracellular space of b. thuringiensis, the aiia ( 4q7 ) gene (an ahl-lactonase gene from b. thuringiensis 4q7), which confers the ability to inhibit plant soft rot disease in b. thuringiensis 4q7, was fused with the upstream sequence of the ctc gene, w ... | 2007 | 17216466 |
| acid ph activation of the pmra/pmrb two-component regulatory system of salmonella enterica. | acid ph often triggers changes in gene expression. however, little is known about the identity of the gene products that sense fluctuations in extracytoplasmic ph. the gram-negative pathogen salmonella enterica serovar typhimurium experiences a number of acidic environments both inside and outside animal hosts. growth in mild acid (ph 5.8) promotes transcription of genes activated by the response regulator pmra, but the signalling pathway(s) that mediates this response has thus far remained unex ... | 2007 | 17229213 |
| [phage system for studying the restriction-modification of erwinia carotovora]. | a model for revealing and type identifying the systems of restriction-modification of phytopathogenic bacterium ewinia carotovora with the help of two virulent polyvalent phages-fe 44 and t7 is proposed in the work. the joint use of the phages permits to identify both the limitations of phages development on the part of rm-systems of three major types, and on the part of the competing episomes. the proposed system also allows to reveal other kinds of limitations, in particular those connected wi ... | 2006 | 17243364 |
| [intragenome heterogeneity of the temperate bacteriophage zf40 erwinia carotovora]. | it has been shown that the temperate bacteriophage zf40 erwinia carotovora combines in it two kinds of intragenome heterogeneity--cyclic permutation and cohesive end structures. the latter reassociate more quickly than analogous cos-sites of the phage lambda escherichia coli. a series of clear-mutants was found after the temperature inactivation of the phage particles; they are the components of the complementation group being involved in the repressor gene. one of the mutants, zf40c(5/5), was i ... | 2006 | 17243365 |
| salmonella typhimurium flhe, a conserved flagellar regulon gene required for swarming. | the salmonella typhimurium gene flhe is located at the end of a large flagellar locus in at least 10 peritrichously flagellated gram-negative bacterial genera, but it shares no significant similarity with other genes. this study shows that flhe is transcribed as part of an flhbae flagellar operon, under the control of the flagellar master regulator flhd(2)c(2). deletion of the chromosomal flhe gene did not affect swimming motility, but it abolished swarming motility across solid agar. swarming w ... | 2007 | 17259626 |
| effective asparagine depletion with pegylated asparaginase results in improved outcomes in adult acute lymphoblastic leukemia: cancer and leukemia group b study 9511. | calgb 9511 used pegaspargase (peg-asp) in lieu of the native enzyme. the aim was to compare differences in overall survival (os) and disease-free survival (dfs) between patients who did and did not achieve asparagine depletion, defined by enzyme levels greater than 0.03 u/ml plasma for 14 consecutive days after at least 1 of 4 planned peg-asp administrations. samples were available from 85 eligible patients. on univariate analyses, the 22 patients who did not achieve asparagine depletion had inf ... | 2007 | 17264295 |
| an informatic pipeline for the data capture and submission of quantitative proteomic data using itraq. | proteomics continues to play a critical role in post-genomic science as continued advances in mass spectrometry and analytical chemistry support the separation and identification of increasing numbers of peptides and proteins from their characteristic mass spectra. in order to facilitate the sharing of this data, various standard formats have been, and continue to be, developed. still not fully mature however, these are not yet able to cope with the increasing number of quantitative proteomic te ... | 2007 | 17270041 |
| characterization of the signaling domain of the no-responsive regulator norr from ralstonia eutropha h16 by site-directed mutagenesis. | in ralstonia eutropha h16, the nitric oxide (no)-responsive transcriptional activator norr controls the expression of a dicistronic operon that encodes a membrane-bound no reductase, norb, and a protein of unknown function, nora. the n-terminal domain (ntd) of norr is responsible for perception of the signal molecule, nitric oxide. thirteen out of 29 conserved residues of the ntd were exchanged by site-directed mutagenesis. replacement of r63, r72, d93, d96, c112, d130, or f137 strongly decrease ... | 2007 | 17277050 |
| species-specific functioning of the pseudomonas xcpq secretin: role for the c-terminal homology domain and lipopolysaccharide. | secretins are oligomeric proteins that mediate the export of macromolecules across the bacterial outer membrane. the members of the secretin superfamily possess a c-terminal homology domain that is important for oligomerization and channel formation, while their n-terminal halves are thought to be involved in system-specific interactions. the xcpq secretin of pseudomonas spp. is a component of the type ii secretion pathway. xcpq from pseudomonas alcaligenes is not able to functionally replace th ... | 2007 | 17277064 |
| interplay between crp-camp and pii-ntr systems forms novel regulatory network between carbon metabolism and nitrogen assimilation in escherichia coli. | in escherichia coli, utilization of carbon sources is regulated by the phosphoenolpyruvate-dependent phosphotransferase system (pts), which modulates the intracellular levels of camp. the camp receptor protein (crp) controls the transcription of many catabolic genes. the availability of nitrogen is sensed by the pii protein at the level of intracellular glutamine. glutamine is transported mainly by glnhpq, and synthesized by glutamine synthetase (gs) encoded by glna. previous studies suggest tha ... | 2007 | 17284458 |
| purification of l-asparaginase from a bacteria erwinia carotovora and effect of a dihydropyrimidine derivative on some of its kinetic parameters. | l-asparaginase shows antileukemic activity and is generally administered in the body in combination with other anticancer drugs like pyrimidine derivatives. in the present study, l-asparaginase was purified from a bacteria erwinia carotovora and the effect of a dihydropyrimidine derivative (1-amino-6-methyl-4-phenyl-2-thioxo, 1,2,3,4-tetrahydropyrimidine-5-carboxylic acid methyl ester) was studied on the kinetic parameters km and vmax of the enzyme using l-asparagine as substrate. the enzyme had ... | 2006 | 17285805 |
| cross talk between type iii secretion and flagellar assembly systems in pseudomonas aeruginosa. | pseudomonas aeruginosa cytotoxicity is linked to a type iii secretion system (t3ss) that delivers effectors into the host cell. we show here that a negative cross-control exists between t3ss and flagellar assembly. we observed that, in a strain lacking flagella, t3ss gene expression, effector secretion, and cytotoxicity were increased. conversely, we revealed that flagellar-gene expression and motility were decreased in a strain overproducing exsa, the t3ss master regulator. interestingly, a non ... | 2007 | 17307856 |