Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| essential role of the sycp chaperone in type iii secretion of the yspp effector. | the ysa type iii secretion (t3s) system enhances gastrointestinal infection by yersinia enterocolitica bv. 1b. one effector protein targeted into host cells is yspp, a protein tyrosine phosphatase. it was determined in this study that the secretion of yspp requires a chaperone, sycp. genetic analysis showed that deletion of sycp completely abolished the secretion of yspp without affecting the secretion of other ysps by the ysa t3s system. analysis of the secretion and translocation signals of ys ... | 2009 | 19114483 |
| regulation of cyclic lipopeptide biosynthesis in pseudomonas fluorescens by the clpp protease. | cyclic lipopeptides produced by pseudomonas species exhibit potent surfactant and broad-spectrum antibiotic properties. their biosynthesis is governed by large multimodular nonribosomal peptide synthetases, but little is known about the genetic regulatory network. this study provides, for the first time, evidence that the serine protease clpp regulates the biosynthesis of massetolides, cyclic lipopeptides involved in swarming motility, biofilm formation, and antimicrobial activity of pseudomonas ... | 2009 | 19114474 |
| regulation of cyclic lipopeptide biosynthesis in pseudomonas fluorescens by the clpp protease. | cyclic lipopeptides produced by pseudomonas species exhibit potent surfactant and broad-spectrum antibiotic properties. their biosynthesis is governed by large multimodular nonribosomal peptide synthetases, but little is known about the genetic regulatory network. this study provides, for the first time, evidence that the serine protease clpp regulates the biosynthesis of massetolides, cyclic lipopeptides involved in swarming motility, biofilm formation, and antimicrobial activity of pseudomonas ... | 2009 | 19114474 |
| genomic resources and tools for gene function analysis in potato. | potato, a highly heterozygous tetraploid, is undergoing an exciting phase of genomics resource development. the potato research community has established extensive genomic resources, such as large expressed sequence tag (est) data collections, microarrays and other expression profiling platforms, and large-insert genomic libraries. moreover, potato will now benefit from a global potato physical mapping effort, which is serving as the underlying resource for a full potato genome sequencing projec ... | 2008 | 19107214 |
| phosphate availability alters lateral root development in arabidopsis by modulating auxin sensitivity via a mechanism involving the tir1 auxin receptor. | the survival of plants, as sessile organisms, depends on a series of postembryonic developmental events that determine the final architecture of plants and allow them to contend with a continuously changing environment. modulation of cell differentiation and organ formation by environmental signals has not been studied in detail. here, we report that alterations in the pattern of lateral root (lr) formation and emergence in response to phosphate (pi) availability is mediated by changes in auxin ... | 2008 | 19106375 |
| the poly(a)-dependent degradation pathway of rpso mrna is primarily mediated by rnase r. | polyadenylation is an important factor controlling rna degradation and rna quality control mechanisms. in this report we demonstrate for the first time that rnase r has in vivo affinity for polyadenylated rna and can be a key enzyme involved in poly(a) metabolism. rnase ii and pnpase, two major rna exonucleases present in escherichia coli, could not account for all the poly(a)-dependent degradation of the rpso mrna. rnase ii can remove the poly(a) tails but fails to degrade the mrna as it cannot ... | 2009 | 19103951 |
| elicitor-induced transcription factors for metabolic reprogramming of secondary metabolism in medicago truncatula. | exposure of medicago truncatula cell suspension cultures to pathogen or wound signals leads to accumulation of various classes of flavonoid and/or triterpene defense molecules, orchestrated via a complex signalling network in which transcription factors (tfs) are essential components. | 2008 | 19102779 |
| pseudomonas savastanoi pv. savastanoi contains two iaal paralogs, one of which exhibits a variable number of a trinucleotide (tac) tandem repeat. | in this study, pseudomonas savastanoi pv. savastanoi isolates were demonstrated to contain two iaal paralogs, which are both chromosomally located in most strains. comparative analysis of iaal nucleotide sequences amplified from these two paralogs revealed that one paralog, iaal(psn), is 100% identical to iaal from p. savastanoi pv. nerii, while the other paralog, iaal(psv), exhibited 93% identity to iaal from pseudomonas syringae pv. tomato (iaal(pto)). a 3-nucleotide motif (tac) comprised of 3 ... | 2009 | 19098222 |
| pseudomonas savastanoi pv. savastanoi contains two iaal paralogs, one of which exhibits a variable number of a trinucleotide (tac) tandem repeat. | in this study, pseudomonas savastanoi pv. savastanoi isolates were demonstrated to contain two iaal paralogs, which are both chromosomally located in most strains. comparative analysis of iaal nucleotide sequences amplified from these two paralogs revealed that one paralog, iaal(psn), is 100% identical to iaal from p. savastanoi pv. nerii, while the other paralog, iaal(psv), exhibited 93% identity to iaal from pseudomonas syringae pv. tomato (iaal(pto)). a 3-nucleotide motif (tac) comprised of 3 ... | 2009 | 19098222 |
| rna silencing is required for arabidopsis defence against verticillium wilt disease. | rna silencing is a conserved mechanism in eukaryotes that plays an important role in various biological processes including regulation of gene expression. rna silencing also plays a role in genome stability and protects plants against invading nucleic acids such as transgenes and viruses. recently, rna silencing has been found to play a role in defence against bacterial plant pathogens in arabidopsis through modulating host defence responses. in this study, it is shown that gene silencing plays ... | 2009 | 19098131 |
| rna silencing is required for arabidopsis defence against verticillium wilt disease. | rna silencing is a conserved mechanism in eukaryotes that plays an important role in various biological processes including regulation of gene expression. rna silencing also plays a role in genome stability and protects plants against invading nucleic acids such as transgenes and viruses. recently, rna silencing has been found to play a role in defence against bacterial plant pathogens in arabidopsis through modulating host defence responses. in this study, it is shown that gene silencing plays ... | 2009 | 19098131 |
| defence reactions in the apoplastic proteome of oilseed rape (brassica napus var. napus) attenuate verticillium longisporum growth but not disease symptoms. | verticillium longisporum is one of the most important pathogens of brassicaceae that remains strictly in the xylem during most stages of its development. it has been suggested that disease symptoms are associated with clogging of xylem vessels. the aim of our study was to investigate extracellular defence reactions induced by v. longisporum in the xylem sap and leaf apoplast of brassica napus var. napus in relation to the development of disease symptoms, photosynthesis and nutrient status. | 2008 | 19094241 |
| xanthomonas campestris overcomes arabidopsis stomatal innate immunity through a dsf cell-to-cell signal-regulated virulence factor. | pathogen-induced stomatal closure is part of the plant innate immune response. phytopathogens using stomata as a way of entry into the leaf must avoid the stomatal response of the host. in this article, we describe a factor secreted by the bacterial phytopathogen xanthomonas campestris pv campestris (xcc) capable of interfering with stomatal closure induced by bacteria or abscisic acid (aba). we found that living xcc, as well as ethyl acetate extracts from xcc culture supernatants, are capable o ... | 2009 | 19091877 |
| overexpression of lipid transfer protein (ltp) genes enhances resistance to plant pathogens and ltp functions in long-distance systemic signaling in tobacco. | the lipid signal is essential for the activation of plant defense responses, but downstream components of the signaling pathway are still poorly defined. to investigate the biological functions of pepper lipid transfer protein (ltp), we carried out virus-induced gene silencing (vigs) in pepper, constitutive expression of caltps and grafting experiments in the tobacco plant. suppression of endogenous caltpi and caltpii by vigs, respectively, resulted in enhanced susceptibility to xanthomonas camp ... | 2009 | 19089429 |
| an orphan luxr homolog of sinorhizobium meliloti affects stress adaptation and competition for nodulation. | the sin/expr quorum-sensing system of sinorhizobium meliloti plays an important role in the symbiotic association with its host plant, medicago sativa. the luxr-type response regulators of the sin system include the synthase (sini)-associated sinr and the orphan regulator expr. interestingly, the s. meliloti rm1021 genome codes for four additional putative orphan luxr homologs whose regulatory roles remain to be identified. these response regulators contain the characteristic domains of the luxr ... | 2009 | 19088317 |
| an orphan luxr homolog of sinorhizobium meliloti affects stress adaptation and competition for nodulation. | the sin/expr quorum-sensing system of sinorhizobium meliloti plays an important role in the symbiotic association with its host plant, medicago sativa. the luxr-type response regulators of the sin system include the synthase (sini)-associated sinr and the orphan regulator expr. interestingly, the s. meliloti rm1021 genome codes for four additional putative orphan luxr homologs whose regulatory roles remain to be identified. these response regulators contain the characteristic domains of the luxr ... | 2009 | 19088317 |
| a chromosomally located trahijkclmn operon encoding a putative type iv secretion system is involved in the virulence of yersinia ruckeri. | nucleotide sequence analysis of the region surrounding the pivet8 insertion site in yersinia ruckeri 150rivixii, previously selected by in vivo expression technology (ivet), revealed the presence of eight genes (trahijkclmn [hereafter referred to collectively as the tra operon or tra cluster]), which are similar both in sequence and organization to the tra operon cluster found in the virulence-related plasmid padap from serratia entomophila. interestingly, the tra cluster of y. ruckeri is chromo ... | 2009 | 19088314 |
| a chromosomally located trahijkclmn operon encoding a putative type iv secretion system is involved in the virulence of yersinia ruckeri. | nucleotide sequence analysis of the region surrounding the pivet8 insertion site in yersinia ruckeri 150rivixii, previously selected by in vivo expression technology (ivet), revealed the presence of eight genes (trahijkclmn [hereafter referred to collectively as the tra operon or tra cluster]), which are similar both in sequence and organization to the tra operon cluster found in the virulence-related plasmid padap from serratia entomophila. interestingly, the tra cluster of y. ruckeri is chromo ... | 2009 | 19088314 |
| molecular analysis of a large subtelomeric nucleotide-binding-site-leucine-rich-repeat family in two representative genotypes of the major gene pools of phaseolus vulgaris. | in common bean, the b4 disease resistance gene cluster is a complex cluster localized at the end of linkage group (lg) b4, containing at least three r specificities to the fungus colletotrichum lindemuthianum. to investigate the evolution of this r cluster since the divergence of andean and mesoamerican gene pools, dna sequences were characterized from two representative genotypes of the two major gene pools of common bean (bat93: mesoamerican; jaloeep558: andean). sequences encoding 29 b4-cc nu ... | 2009 | 19087965 |
| the chromatin remodeler splayed regulates specific stress signaling pathways. | organisms are continuously exposed to a myriad of environmental stresses. central to an organism's survival is the ability to mount a robust transcriptional response to the imposed stress. an emerging mechanism of transcriptional control involves dynamic changes in chromatin structure. alterations in chromatin structure are brought about by a number of different mechanisms, including chromatin modifications, which covalently modify histone proteins; incorporation of histone variants; and chromat ... | 2008 | 19079584 |
| gdsl lipase-like 1 regulates systemic resistance associated with ethylene signaling in arabidopsis. | systemic resistance is induced by necrotizing pathogenic microbes and non-pathogenic rhizobacteria and confers protection against a broad range of pathogens. here we show that arabidopsis gdsl lipase-like 1 (glip1) plays an important role in plant immunity, eliciting both local and systemic resistance in plants. glip1 functions independently of salicylic acid but requires ethylene signaling. enhancement of glip1 expression in plants increases resistance to pathogens including alternaria brassici ... | 2009 | 19077166 |
| de novo assembly of the pseudomonas syringae pv. syringae b728a genome using illumina/solexa short sequence reads. | illumina's genome analyzer generates ultra-short sequence reads, typically 36 nucleotides in length, and is primarily intended for resequencing. we tested the potential of this technology for de novo sequence assembly on the 6 mbp genome of pseudomonas syringae pv. syringae b728a with several freely available assembly software packages. using an unpaired data set, velvet assembled >96% of the genome into contigs with an n50 length of 8289 nucleotides and an error rate of 0.33%. edena generated s ... | 2009 | 19077061 |
| a metasystem of framework model organisms to study emergence of new host-microbe adaptations. | an unintended consequence of global industrialization and associated societal rearrangements is new interactions of microbes and potential hosts (especially mammals and plants), providing an opportunity for the rapid emergence of host-microbe adaptation and eventual establishment of new microbe-related diseases. we describe a new model system comprising the model plant arabidopsis thaliana and several microbes, each representing different modes of interaction, to study such "maladaptations". the ... | 2008 | 19066631 |
| the arabidopsis homologs of ccr4-associated factor 1 show mrna deadenylation activity and play a role in plant defence responses. | messenger rna (mrna) turnover in eukaryotic cells begins with shortening of the poly (a) tail at the 3' end, a process called deadenylation. in yeast, the deadenylation reaction is predominantly mediated by ccr4 and ccr4-associated factor 1 (caf1), two components of the well-characterised protein complex named ccr4-not. we report here that atcaf1a and atcaf1b, putative arabidopsis homologs of the yeast caf1 gene, partially complement the growth defect of the yeast caf1 mutant in the presence of ... | 2009 | 19065152 |
| arabidopsis thaliana genes encoding defense signaling and recognition proteins exhibit contrasting evolutionary dynamics. | the interplay between pathogen effectors, their host targets, and cognate recognition proteins provides various opportunities for antagonistic cycles of selection acting on plant and pathogen to achieve or abrogate resistance, respectively. selection has previously been shown to maintain diversity in plant proteins involved in pathogen recognition and some of their cognate pathogen effectors. we analyzed the signatures of selection on 10 arabidopsis thaliana genes encoding defense signal transdu ... | 2009 | 19064707 |
| plant pattern-recognition receptor fls2 is directed for degradation by the bacterial ubiquitin ligase avrptob. | an important layer of active defense in plant immunity is the detection of pathogen-associated molecular patterns (pamps) mediated by cell-surface receptors. for the establishment of disease, pathogens depend on the ability to overcome pamp perception and disable plant signaling pathways activated in response to pamps. pattern recognition receptors (prrs) are therefore prime targets for pathogen effectors. fls2, its coreceptor bak1, and efr encode receptor-like kinases that play a role in immuni ... | 2008 | 19062288 |
| identification of novel type iii secretion effectors in xanthomonas oryzae pv. oryzae. | many gram-negative bacteria secrete so-called effector proteins via a type iii secretion (t3s) system. through genome screening for genes encoding potential t3s effectors, 60 candidates were selected from rice pathogen xanthomonas oryzae pv. oryzae maff311018 using these criteria: i) homologs of known t3s effectors in plant-pathogenic bacteria, ii) genes with expression regulated by hrp regulatory protein hrpx, or iii) proteins with n-terminal amino acid patterns associated with t3s substrates o ... | 2009 | 19061406 |
| gmrar1 and gmsgt1 are required for basal, r gene-mediated and systemic acquired resistance in soybean. | rar1, sgt1, and hsp90 are important components of effector-triggered immunity (eti) in diverse plants, where rar1 and sgt1 are thought to serve as hsp90 co-chaperones. we show that eti in soybean requires rar1 and sgt1 but not hsp90. rsv1-mediated extreme resistance to soybean mosaic virus (smv) and rpg-1b-mediated resistance to pseudomonas syringae were compromised in plants silenced for gmrar1 and gmsgt1-2 but not gmhsp90. this suggests that rar1- or sgt1-dependant signaling is not always asso ... | 2009 | 19061405 |
| a draft genome sequence of pseudomonas syringae pv. tomato t1 reveals a type iii effector repertoire significantly divergent from that of pseudomonas syringae pv. tomato dc3000. | diverse gene products including phytotoxins, pathogen-associated molecular patterns, and type iii secreted effectors influence interactions between pseudomonas syringae strains and plants, with additional yet uncharacterized factors likely contributing as well. of particular interest are those interactions governing pathogen-host specificity. comparative genomics of closely related pathogens with different host specificity represents an excellent approach for identification of genes contributing ... | 2009 | 19061402 |
| production of glucaric acid from a synthetic pathway in recombinant escherichia coli. | a synthetic pathway has been constructed for the production of glucuronic and glucaric acids from glucose in escherichia coli. coexpression of the genes encoding myo-inositol-1-phosphate synthase (ino1) from saccharomyces cerevisiae and myo-inositol oxygenase (miox) from mice led to production of glucuronic acid through the intermediate myo-inositol. glucuronic acid concentrations up to 0.3 g/liter were measured in the culture broth. the activity of miox was rate limiting, resulting in the accum ... | 2009 | 19060162 |
| production of glucaric acid from a synthetic pathway in recombinant escherichia coli. | a synthetic pathway has been constructed for the production of glucuronic and glucaric acids from glucose in escherichia coli. coexpression of the genes encoding myo-inositol-1-phosphate synthase (ino1) from saccharomyces cerevisiae and myo-inositol oxygenase (miox) from mice led to production of glucuronic acid through the intermediate myo-inositol. glucuronic acid concentrations up to 0.3 g/liter were measured in the culture broth. the activity of miox was rate limiting, resulting in the accum ... | 2009 | 19060162 |
| y4lo of rhizobium sp. strain ngr234 is a symbiotic determinant required for symbiosome differentiation. | type 3 (t3) effector proteins, secreted by nitrogen-fixing rhizobia with a bacterial t3 secretion system, affect the nodulation of certain host legumes. the open reading frame y4lo of rhizobium sp. strain ngr234 encodes a protein with sequence similarities to t3 effectors from pathogenic bacteria (the yopj effector family). transcription studies showed that the promoter activity of y4lo depended on the transcriptional activator ttsi. recombinant y4lo protein expressed in escherichia coli did not ... | 2009 | 19060155 |
| y4lo of rhizobium sp. strain ngr234 is a symbiotic determinant required for symbiosome differentiation. | type 3 (t3) effector proteins, secreted by nitrogen-fixing rhizobia with a bacterial t3 secretion system, affect the nodulation of certain host legumes. the open reading frame y4lo of rhizobium sp. strain ngr234 encodes a protein with sequence similarities to t3 effectors from pathogenic bacteria (the yopj effector family). transcription studies showed that the promoter activity of y4lo depended on the transcriptional activator ttsi. recombinant y4lo protein expressed in escherichia coli did not ... | 2009 | 19060155 |
| purine utilization by klebsiella oxytoca m5al: genes for ring-oxidizing and -opening enzymes. | the enterobacterium klebsiella oxytoca uses a variety of inorganic and organic nitrogen sources, including purines, nitrogen-rich compounds that are widespread in the biosphere. we have identified a 23-gene cluster that encodes the enzymes for utilizing purines as the sole nitrogen source. growth and complementation tests with insertion mutants, combined with sequence comparisons, reveal functions for the products of these genes. here, we report our characterization of 12 genes, one encoding gua ... | 2009 | 19060149 |
| purine utilization by klebsiella oxytoca m5al: genes for ring-oxidizing and -opening enzymes. | the enterobacterium klebsiella oxytoca uses a variety of inorganic and organic nitrogen sources, including purines, nitrogen-rich compounds that are widespread in the biosphere. we have identified a 23-gene cluster that encodes the enzymes for utilizing purines as the sole nitrogen source. growth and complementation tests with insertion mutants, combined with sequence comparisons, reveal functions for the products of these genes. here, we report our characterization of 12 genes, one encoding gua ... | 2009 | 19060149 |
| cloning and characterization of uronate dehydrogenases from two pseudomonads and agrobacterium tumefaciens strain c58. | uronate dehydrogenase has been cloned from pseudomonas syringae pv. tomato strain dc3000, pseudomonas putida kt2440, and agrobacterium tumefaciens strain c58. the genes were identified by using a novel complementation assay employing an escherichia coli mutant incapable of consuming glucuronate as the sole carbon source but capable of growth on glucarate. a shotgun library of p. syringae was screened in the mutant e. coli by growing transformed cells on minimal medium containing glucuronic acid. ... | 2009 | 19060141 |
| cloning and characterization of uronate dehydrogenases from two pseudomonads and agrobacterium tumefaciens strain c58. | uronate dehydrogenase has been cloned from pseudomonas syringae pv. tomato strain dc3000, pseudomonas putida kt2440, and agrobacterium tumefaciens strain c58. the genes were identified by using a novel complementation assay employing an escherichia coli mutant incapable of consuming glucuronate as the sole carbon source but capable of growth on glucarate. a shotgun library of p. syringae was screened in the mutant e. coli by growing transformed cells on minimal medium containing glucuronic acid. ... | 2009 | 19060141 |
| mycobacterium avium genes mav_5138 and mav_3679 are transcriptional regulators that play a role in invasion of epithelial cells, in part by their regulation of cipa, a putative surface protein interacting with host cell signaling pathways. | the mycobacterium avium complex (mac) is an important group of opportunistic pathogens for birds, cattle, swine, and immunosuppressed humans. although invasion of epithelial cells lining the intestine is the chief point of entry for these organisms, little is known about the mechanisms by which members of the mac are taken up by these cells. studies with m. avium have shown that cytoskeletal rearrangement via activation of the small g-protein cdc42 is involved and that this activation is regulat ... | 2009 | 19060135 |
| mycobacterium avium genes mav_5138 and mav_3679 are transcriptional regulators that play a role in invasion of epithelial cells, in part by their regulation of cipa, a putative surface protein interacting with host cell signaling pathways. | the mycobacterium avium complex (mac) is an important group of opportunistic pathogens for birds, cattle, swine, and immunosuppressed humans. although invasion of epithelial cells lining the intestine is the chief point of entry for these organisms, little is known about the mechanisms by which members of the mac are taken up by these cells. studies with m. avium have shown that cytoskeletal rearrangement via activation of the small g-protein cdc42 is involved and that this activation is regulat ... | 2009 | 19060135 |
| how nature morphs peptide scaffolds into antibiotics. | the conventional notion that peptides are poor candidates for orally available drugs because of protease-sensitive peptide bonds, intrinsic hydrophilicity, and ionic charges contrasts with the diversity of antibiotic natural products with peptide-based frameworks that are synthesized and utilized by nature. several of these antibiotics, including penicillin and vancomycin, are employed to treat bacterial infections in humans and have been best-selling therapeutics for decades. others might provi ... | 2009 | 19058272 |
| global transcriptional responses of pseudomonas syringae dc3000 to changes in iron bioavailability in vitro. | pseudomonas syringae pv tomato dc3000 (dc3000) is a gram-negative model plant pathogen that is found in a wide variety of environments. to survive in these diverse conditions it must sense and respond to various environmental cues. one micronutrient required for most forms of life is iron. bioavailable iron has been shown to be an important global regulator for many bacteria where it not only regulates a wide variety of genes involved in general cell physiology but also virulence determinants. i ... | 2008 | 19055731 |
| reversal of an immunity associated plant cell death program by the growth regulator auxin. | abstract: | 2008 | 19055721 |
| the pseudomonas syringae effector protein, avrrps4, requires in planta processing and the krvy domain to function. | a pseudomonas syringae pv. pisi effector protein, avrrps4, triggers rps4-dependent immunity in arabidopsis. we characterized biochemical and genetic aspects of avrrps4 function. secretion of avrrps4 from pst dc3000 is type iii secretion-dependent, and avrrps4 is processed into a smaller form in plant cells but not in bacteria or yeast. agrobacterium-mediated transient expression analysis of n-terminally truncated avrrps4 mutants revealed that the c-terminal 88 amino acids are sufficient to trigg ... | 2009 | 19054367 |
| global phenotypic characterization of bacteria. | the measure of the quality of a systems biology model is how well it can reproduce and predict the behaviors of a biological system such as a microbial cell. in recent years, these models have been built up in layers, and each layer has been growing in sophistication and accuracy in parallel with a global data set to challenge and validate the models in predicting the content or activities of genes (genomics), proteins (proteomics), metabolites (metabolomics), and ultimately cell phenotypes (phe ... | 2008 | 19054113 |
| global phenotypic characterization of bacteria. | the measure of the quality of a systems biology model is how well it can reproduce and predict the behaviors of a biological system such as a microbial cell. in recent years, these models have been built up in layers, and each layer has been growing in sophistication and accuracy in parallel with a global data set to challenge and validate the models in predicting the content or activities of genes (genomics), proteins (proteomics), metabolites (metabolomics), and ultimately cell phenotypes (phe ... | 2008 | 19054113 |
| combining subproteome enrichment and rubisco depletion enables identification of low abundance proteins differentially regulated during plant defense. | transgenic arabidopsis conditionally expressing the bacterial avrrpm1 type iii effector under the control of a dexamethasone-responsive promoter were used for proteomics studies. this model system permits study of an individual effector without interference from additional bacterial components. coupling of different prefractionation approaches to high resolution 2-de facilitated the discovery of low abundance proteins - enabling the identification of proteins that have escaped detection in simil ... | 2009 | 19053141 |
| possible effects of microbial ecto-nucleoside triphosphate diphosphohydrolases on host-pathogen interactions. | in humans, purinergic signaling plays an important role in the modulation of immune responses through specific receptors that recognize nucleoside tri- and diphosphates as signaling molecules. ecto-nucleoside triphosphate diphosphohydrolases (ecto-ntpdases) have important roles in the regulation of purinergic signaling by controlling levels of extracellular nucleotides. this process is key to pathophysiological protective responses such as hemostasis and inflammation. ecto-ntpdases are found in ... | 2008 | 19052327 |
| identification and characterization of sigma, a novel component of the staphylococcus aureus stress and virulence responses. | s. aureus is a highly successful pathogen that is speculated to be the most common cause of human disease. the progression of disease in s. aureus is subject to multi-factorial regulation, in response to the environments encountered during growth. this adaptive nature is thought to be central to pathogenesis, and is the result of multiple regulatory mechanisms employed in gene regulation. in this work we describe the existence of a novel s. aureus regulator, an as yet uncharacterized ecf-sigma f ... | 2008 | 19050758 |
| gef-h1 mediated control of nod1 dependent nf-kappab activation by shigella effectors. | shigella flexneri has evolved the ability to modify host cell function with intracellular active effectors to overcome the intestinal barrier. the detection of these microbial effectors and the initiation of innate immune responses are critical for rapid mucosal defense activation. the guanine nucleotide exchange factor h1 (gef-h1) mediates rhoa activation required for cell invasion by the enteroinvasive pathogen shigella flexneri. surprisingly, gef-h1 is requisite for nf-kappab activation in re ... | 2008 | 19043560 |
| mosaic: an online database dedicated to the comparative genomics of bacterial strains at the intra-species level. | the recent availability of complete sequences for numerous closely related bacterial genomes opens up new challenges in comparative genomics. several methods have been developed to align complete genomes at the nucleotide level but their use and the biological interpretation of results are not straightforward. it is therefore necessary to develop new resources to access, analyze, and visualize genome comparisons. | 2008 | 19038022 |
| an important role of a bahd acyl transferase-like protein in plant innate immunity. | salicylic acid (sa) is an important regulator of plant resistance to biotrophic and hemi-biotrophic pathogens. the enhanced pseudomonas susceptibility 1 (eps1) mutant in arabidopsis thaliana is hypersusceptible to both virulent and avirulent strains of the bacterial pathogen pseudomonas syringae. through positional cloning, the eps1 gene was isolated and found to encode a novel member of the bahd acyltransferase superfamily. pathogen-induced accumulation of sa and expression of pathogenesis-rela ... | 2009 | 19036031 |
| interaction of cisplatin and analogues with a met-rich protein site. | the chaperone protein copc from pseudomonas syringae features high-affinity binding sites (k (d) ~ 10(-13) m) for both cu(i) (met-rich) and cu(ii) (his-rich). when presented with these sites in the apoprotein, electrospray ionisation mass spectrometry confirmed that cis-pt(nh(3))(2)cl(2) (cisplatin) and the fragments [pt(ii)l](2+) (l is 1,2-diaminoethane, 2,2'-bipyridine) occupied the cu(i) site specifically in the 1:1 pt-copc adducts (purified by cation-exchange chromatography). the cis-pt(nh(3 ... | 2009 | 19034536 |
| the transcriptional activator pti4 is required for the recruitment of a repressosome nucleated by repressor sebf at the potato pr-10a gene. | transcriptional reprogramming is critical for plant disease resistance responses. in potato (solanum tuberosum), the marker gene pathogenesis-related-10a (pr-10a) is transcriptionally activated by pathogens, wounding, or elicitor treatment. activation of pr-10a requires the recruitment of the activator why1 to its promoter. in addition, pr-10a is negatively regulated by the repressor sebf (for silencer element binding factor). here, we show through a yeast two-hybrid screen that sebf interacts w ... | 2008 | 19028963 |
| oryr is a luxr-family protein involved in interkingdom signaling between pathogenic xanthomonas oryzae pv. oryzae and rice. | xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight in rice, contains a regulator that is encoded in the genome, designated oryr, which belongs to the n-acyl homoserine lactone (ahl)-dependent quorum-sensing luxr subfamily of proteins. however, we previously reported that x. oryzae pv. oryzae does not make ahls and does not possess a luxi-family ahl synthase and that the oryr protein is solubilized by a compound present in rice. in this study we obtained further evidence tha ... | 2009 | 19028884 |
| oryr is a luxr-family protein involved in interkingdom signaling between pathogenic xanthomonas oryzae pv. oryzae and rice. | xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight in rice, contains a regulator that is encoded in the genome, designated oryr, which belongs to the n-acyl homoserine lactone (ahl)-dependent quorum-sensing luxr subfamily of proteins. however, we previously reported that x. oryzae pv. oryzae does not make ahls and does not possess a luxi-family ahl synthase and that the oryr protein is solubilized by a compound present in rice. in this study we obtained further evidence tha ... | 2009 | 19028884 |
| geographic, seasonal, and precipitation chemistry influence on the abundance and activity of biological ice nucleators in rain and snow. | biological ice nucleators (in) function as catalysts for freezing at relatively warm temperatures (warmer than -10 degrees c). we examined the concentration (per volume of liquid) and nature of in in precipitation collected from montana and louisiana, the alps and pyrenees (france), ross island (antarctica), and yukon (canada). the temperature of detectable ice-nucleating activity for more than half of the samples was > or = -5 degrees c based on immersion freezing testing. digestion of the samp ... | 2008 | 19028877 |
| pcr-based rapid genotyping of stenotrophomonas maltophilia isolates. | all bacterial genomes contain repetitive sequences which are members of specific dna families. such repeats may occur as single units, or found clustered in multiple copies in a head-to-tail configuration at specific loci. the number of clustered units per locus is a strain-defining parameter. assessing the length variability of clusters of repeats is a versatile typing methodology known as multilocus variable number of tandem repeat analysis (mlva). | 2008 | 19025624 |
| engineering and applications of fungal laccases for organic synthesis. | laccases are multi-copper containing oxidases (ec 1.10.3.2), widely distributed in fungi, higher plants and bacteria. laccase catalyses the oxidation of phenols, polyphenols and anilines by one-electron abstraction, with the concomitant reduction of oxygen to water in a four-electron transfer process. in the presence of small redox mediators, laccase offers a broader repertory of oxidations including non-phenolic substrates. hence, fungal laccases are considered as ideal green catalysts of great ... | 2008 | 19019256 |
| genome-wide survey of prokaryotic serine proteases: analysis of distribution and domain architectures of five serine protease families in prokaryotes. | serine proteases are one of the most abundant groups of proteolytic enzymes found in all the kingdoms of life. while studies have established significant roles for many prokaryotic serine proteases in several physiological processes, such as those associated with metabolism, cell signalling, defense response and development, functional associations for a large number of prokaryotic serine proteases are relatively unknown. current analysis is aimed at understanding the distribution and probable b ... | 2008 | 19019219 |
| identification of vcea and vcec, two members of the vjbr regulon that are translocated into macrophages by the brucella type iv secretion system. | survival and replication inside host cells by brucella spp. requires a type iv secretion system (t4ss), encoded by the virb locus. however, the identity of the molecules secreted by the t4ss has remained elusive. we hypothesized that proteins translocated by the t4ss would be co-regulated with the virb operon. the luxr family regulator vjbr, known to regulate virb, bound a fragment of the virb promoter containing an 18 bp palindromic motif (virb promoter box), showing that vjbr regulated the vir ... | 2008 | 19019140 |
| wtse, an avre-family type iii effector protein of pantoea stewartii subsp. stewartii, causes cell death in non-host plants. | pantoea stewartii subsp. stewartii (pnss) causes stewart's bacterial wilt of sweet corn and leaf blight of maize. the pathogenicity of pnss depends on synthesis of extracellular polysaccharide and an hrp type iii secretion system. wtse, a type iii secreted effector protein, is essential for the virulence of pnss on corn. it belongs to the avre family of effectors, which includes dspa/e from erwinia amylovora and avre1 from pseudomonas syringae. previously, wtse was shown to cause disease-associa ... | 2008 | 19018993 |
| de novo assembly using low-coverage short read sequence data from the rice pathogen pseudomonas syringae pv. oryzae. | we developed a novel approach for de novo genome assembly using only sequence data from high-throughput short read sequencing technologies. by combining data generated from 454 life sciences (roche) and illumina (formerly known as solexa sequencing) sequencing platforms, we reliably assembled genomes into large scaffolds at a fraction of the traditional cost and without use of a reference sequence. we applied this method to two isolates of the phytopathogenic bacteria pseudomonas syringae. seque ... | 2009 | 19015323 |
| the legionella pneumophila replication vacuole: making a cosy niche inside host cells. | the pathogenesis of legionella pneumophila is derived from its growth within lung macrophages after aerosols are inhaled from contaminated water sources. interest in this bacterium stems from its ability to manipulate host cell vesicular-trafficking pathways and establish a membrane-bound replication vacuole, making it a model for intravacuolar pathogens. establishment of the replication compartment requires a specialized translocation system that transports a large cadre of protein substrates a ... | 2009 | 19011659 |
| the legionella pneumophila replication vacuole: making a cosy niche inside host cells. | the pathogenesis of legionella pneumophila is derived from its growth within lung macrophages after aerosols are inhaled from contaminated water sources. interest in this bacterium stems from its ability to manipulate host cell vesicular-trafficking pathways and establish a membrane-bound replication vacuole, making it a model for intravacuolar pathogens. establishment of the replication compartment requires a specialized translocation system that transports a large cadre of protein substrates a ... | 2009 | 19011659 |
| xylella fastidiosa afimbrial adhesins mediate cell transmission to plants by leafhopper vectors. | the interactions between the economically important plant-pathogenic bacterium xylella fastidiosa and its leafhopper vectors are poorly characterized. we used different approaches to determine how x. fastidiosa cells interact with the cuticular surface of the foreguts of vectors. we demonstrate that x. fastidiosa binds to different polysaccharides with various affinities and that these interactions are mediated by cell surface carbohydrate-binding proteins. in addition, competition assays showed ... | 2009 | 19011051 |
| xylella fastidiosa afimbrial adhesins mediate cell transmission to plants by leafhopper vectors. | the interactions between the economically important plant-pathogenic bacterium xylella fastidiosa and its leafhopper vectors are poorly characterized. we used different approaches to determine how x. fastidiosa cells interact with the cuticular surface of the foreguts of vectors. we demonstrate that x. fastidiosa binds to different polysaccharides with various affinities and that these interactions are mediated by cell surface carbohydrate-binding proteins. in addition, competition assays showed ... | 2009 | 19011051 |
| the blcc (attm) lactonase of agrobacterium tumefaciens does not quench the quorum-sensing system that regulates ti plasmid conjugative transfer. | the conjugative transfer of agrobacterium plasmids is controlled by a quorum-sensing system consisting of trar and its acyl-homoserine lactone (hsl) ligand. the acyl-hsl is essential for the trar-mediated activation of the ti plasmid tra genes. strains a6 and c58 of agrobacterium tumefaciens produce a lactonase, blcc (attm), that can degrade the quormone, leading some to conclude that the enzyme quenches the quorum-sensing system. we tested this hypothesis by examining the effects of the mutatio ... | 2009 | 19011037 |
| the blcc (attm) lactonase of agrobacterium tumefaciens does not quench the quorum-sensing system that regulates ti plasmid conjugative transfer. | the conjugative transfer of agrobacterium plasmids is controlled by a quorum-sensing system consisting of trar and its acyl-homoserine lactone (hsl) ligand. the acyl-hsl is essential for the trar-mediated activation of the ti plasmid tra genes. strains a6 and c58 of agrobacterium tumefaciens produce a lactonase, blcc (attm), that can degrade the quormone, leading some to conclude that the enzyme quenches the quorum-sensing system. we tested this hypothesis by examining the effects of the mutatio ... | 2009 | 19011037 |
| molecular analysis of post-harvest withering in grape by aflp transcriptional profiling. | post-harvest withering of grape berries is used in the production of dessert and fortified wines to alter must quality characteristics and increase the concentration of simple sugars. the molecular processes that occur during withering are poorly understood, so a detailed transcriptomic analysis of post-harvest grape berries was carried out by aflp-transcriptional profiling analysis. this will help to elucidate the molecular mechanisms of berry withering and will provide an opportunity to select ... | 2008 | 19010774 |
| rapid evolution and the importance of recombination to the gastroenteric pathogen campylobacter jejuni. | responsible for the majority of bacterial gastroenteritis in the developed world, campylobacter jejuni is a pervasive pathogen of humans and animals, but its evolution is obscure. in this paper, we exploit contemporary genetic diversity and empirical evidence to piece together the evolutionary history of c. jejuni and quantify its evolutionary potential. our combined population genetics-phylogenetics approach reveals a surprising picture. campylobacter jejuni is a rapidly evolving species, subje ... | 2009 | 19008526 |
| rapid evolution and the importance of recombination to the gastroenteric pathogen campylobacter jejuni. | responsible for the majority of bacterial gastroenteritis in the developed world, campylobacter jejuni is a pervasive pathogen of humans and animals, but its evolution is obscure. in this paper, we exploit contemporary genetic diversity and empirical evidence to piece together the evolutionary history of c. jejuni and quantify its evolutionary potential. our combined population genetics-phylogenetics approach reveals a surprising picture. campylobacter jejuni is a rapidly evolving species, subje ... | 2009 | 19008526 |
| an inositolphosphorylceramide synthase is involved in regulation of plant programmed cell death associated with defense in arabidopsis. | the arabidopsis thaliana resistance gene rpw8 triggers the hypersensitive response (hr) to restrict powdery mildew infection via the salicylic acid-dependent signaling pathway. to further understand how rpw8 signaling is regulated, we have conducted a genetic screen to identify mutations enhancing rpw8-mediated hr-like cell death (designated erh). here, we report the isolation and characterization of the arabidopsis erh1 mutant, in which the at2g37940 locus is knocked out by a t-dna insertion. l ... | 2008 | 19001565 |
| systemic resistance and lipoxygenase-related defence response induced in tomato by pseudomonas putida strain btp1. | previous studies showed the ability of pseudomonas putida strain btp1 to promote induced systemic resistance (isr) in different host plants. since isr is long-lasting and not conducive for development of resistance of the targeted pathogen, this phenomenon can take part of disease control strategies. however, in spite of the numerous examples of isr induced by pgpr in plants, only a few biochemical studies have associated the protective effect with specific host metabolic changes. | 2008 | 19000301 |
| structure of the shigella t3ss effector ipah defines a new class of e3 ubiquitin ligases. | ipah proteins are e3 ubiquitin ligases delivered by the type iii secretion apparatus into host cells upon infection of humans by the gram-negative pathogen shigella flexneri. these proteins comprise a variable leucine-rich repeat-containing n-terminal domain and a conserved c-terminal domain harboring an invariant cysteine residue that is crucial for activity. ipah homologs are encoded by diverse animal and plant pathogens. here we demonstrate that the ipah c-terminal domain carries the catalyti ... | 2008 | 18997778 |
| a novel l-amino acid ligase is encoded by a gene in the phaseolotoxin biosynthetic gene cluster from pseudomonas syringae pv. phaseolicola 1448a. | in the phaseolotoxin biosynthetic gene cluster of pseudomonas syringae pv. phaseolicola 1448a, the pspph_4299 gene encodes a novel l-amino acid ligase. the pspph_4299 protein synthesized various hetero-dipeptides containing basic amino acids in an atp-dependent manner, and also synthesized alanyl-homoarginine, part of the phaseolotoxin scaffold. | 2008 | 18997422 |
| two dissimilar n-acyl-homoserine lactone acylases of pseudomonas syringae influence colony and biofilm morphology. | plant aerial surfaces comprise a complex habitat for microorganisms, and many plant-associated bacteria, such as the pathogen pseudomonas syringae, exhibit density-dependent survival on leaves by utilizing quorum sensing (qs). qs is often mediated by diffusible signals called n-acyl-homoserine lactones (ahls), and p. syringae utilizes n-3-oxo-hexanoyl-dl-homoserine lactone (3oc6hsl) to control traits influencing epiphytic fitness and virulence. the p. syringae pathovar syringae b728a genome sequ ... | 2009 | 18997027 |
| two dissimilar n-acyl-homoserine lactone acylases of pseudomonas syringae influence colony and biofilm morphology. | plant aerial surfaces comprise a complex habitat for microorganisms, and many plant-associated bacteria, such as the pathogen pseudomonas syringae, exhibit density-dependent survival on leaves by utilizing quorum sensing (qs). qs is often mediated by diffusible signals called n-acyl-homoserine lactones (ahls), and p. syringae utilizes n-3-oxo-hexanoyl-dl-homoserine lactone (3oc6hsl) to control traits influencing epiphytic fitness and virulence. the p. syringae pathovar syringae b728a genome sequ ... | 2009 | 18997027 |
| the diverse chec-type phosphatases: chemotaxis and beyond. | a new class of protein phosphatases has emerged in the study of bacterial/archaeal chemotaxis, the chec-type phosphatases. these proteins are distinct and unrelated to the well-known chey-p phosphatase chez, though they have convergently evolved to dephosphorylate the same target. the family contains a common consensus sequence d/s-x(3)-e-x(2)-n-x(22)-p that defines the phosphatase active site, of which there are often two per protein. three distinct subgroups make up the family: chec, fliy and ... | 2008 | 18990184 |
| pilus operon evolution in streptococcus pneumoniae is driven by positive selection and recombination. | the evolution of bacterial organelles involved in host-pathogen interactions is subject to intense and competing selective pressures due to the need to maintain function while escaping the host immune response. to characterize the interplay of these forces in an important pathogen, we sequenced the rlra islet, a chromosomal region encoding for a pilus-like structure involved in adherence to lung epithelial cells in vitro and in colonization in a murine model of infection, in 44 clinical isolates ... | 2008 | 18987753 |
| identification of proteins from membrane preparations by a combination of maldi tof-tof and lc-coupled linear ion trap ms analysis of an antarctic bacterium pseudomonas syringae lz4w, a strain with unsequenced genome. | multidimensional protein identification technology helps in identifying a large number of proteins with esi by sequencing several peptides with ms/ms methods. when ionization and separation of different hydrophobic and hydrophilic peptides in a single process are difficult, a combination of lc-coupled linear ion trap ms and maldi tof/tof can be used for identification of proteins as shown in the present study. we have used this combinational approach to identify membrane proteins of the antarcti ... | 2008 | 18985660 |
| the arabidopsis gras protein scl14 interacts with class ii tga transcription factors and is essential for the activation of stress-inducible promoters. | the plant signaling molecule salicylic acid (sa) and/or xenobiotic chemicals like the auxin mimic 2,4-d induce transcriptional activation of defense- and stress-related genes that contain activation sequence-1 (as-1)-like cis-elements in their promoters. as-1-like sequences are recognized by basic/leucine zipper transcription factors of the tga family. expression of genes related to the sa-dependent defense program systemic acquired resistance requires the tga-interacting protein npr1. however, ... | 2008 | 18984675 |
| long-term effects of inducible mutagenic dna repair on relative fitness and phenotypic diversification in pseudomonas cichorii 302959. | mutagenic dna repair (mdr) employs low-fidelity dna polymerases capable of replicating past dna lesions resulting from exposure to high-energy ultraviolet radiation (uvr). mdr confers uvr tolerance and activation initiates a transient mutator phenotype that may provide opportunities for adaptation. to investigate the potential role of mdr in adaptation, we have propagated parallel lineages of the highly mutable epiphytic plant pathogen pseudomonas cichorii 302959 with daily uvr activation (uvr l ... | 2009 | 18984570 |
| the pseudomonas syringae type iii effector avrrpm1 induces significant defenses by activating the arabidopsis nucleotide-binding leucine-rich repeat protein rps2. | plant disease resistance (r) proteins recognize potential pathogens expressing corresponding avirulence (avr) proteins through 'gene-for-gene' interactions. rpm1 is an arabidopsis r-protein that triggers a robust defense response upon recognizing the pseudomonas syringae effector avrrpm1. avr-proteins of phytopathogenic bacteria include type iii effector proteins that are often capable of enhancing virulence when not recognized by an r-protein. in rpm1 plants, avrrpm1 suppresses basal defenses i ... | 2009 | 18980653 |
| separable roles of the pseudomonas syringae pv. phaseolicola accessory protein hrpz1 in ion-conducting pore formation and activation of plant immunity. | the hrpz1 gene product from phytopathogenic pseudomonas syringae is secreted in a type-iii secretion system-dependent manner during plant infection. the ability of hrpz1 to form ion-conducting pores is proposed to contribute to bacterial effector delivery into host cells, or may facilitate the nutrition of bacteria in the apoplast. furthermore, hrpz1 is reminiscent of a pathogen-associated molecular pattern (pamp) that triggers immunity-associated responses in a variety of plants. here, we provi ... | 2009 | 18980650 |
| the transcriptome of syncytia induced by the cyst nematode heterodera schachtii in arabidopsis roots. | arabidopsis thaliana is a host for the sugar beet cyst nematode heterodera schachtii. juvenile nematodes invade the roots and induce the development of a syncytium, which functions as a feeding site for the nematode. here, we report on the transcriptome of syncytia induced in the roots of arabidopsis. microaspiration was employed to harvest pure syncytium material, which was then used to prepare rna for hybridization to affymetrix genechips. initial data analysis showed that the gene expression ... | 2008 | 18980640 |
| the transcriptome of syncytia induced by the cyst nematode heterodera schachtii in arabidopsis roots. | arabidopsis thaliana is a host for the sugar beet cyst nematode heterodera schachtii. juvenile nematodes invade the roots and induce the development of a syncytium, which functions as a feeding site for the nematode. here, we report on the transcriptome of syncytia induced in the roots of arabidopsis. microaspiration was employed to harvest pure syncytium material, which was then used to prepare rna for hybridization to affymetrix genechips. initial data analysis showed that the gene expression ... | 2008 | 18980640 |
| a genomic distance based on mum indicates discontinuity between most bacterial species and genera. | the fundamental unit of biological diversity is the species. however, a remarkable extent of intraspecies diversity in bacteria was discovered by genome sequencing, and it reveals the need to develop clear criteria to group strains within a species. two main types of analyses used to quantify intraspecies variation at the genome level are the average nucleotide identity (ani), which detects the dna conservation of the core genome, and the dna content, which calculates the proportion of dna share ... | 2009 | 18978054 |
| a genomic distance based on mum indicates discontinuity between most bacterial species and genera. | the fundamental unit of biological diversity is the species. however, a remarkable extent of intraspecies diversity in bacteria was discovered by genome sequencing, and it reveals the need to develop clear criteria to group strains within a species. two main types of analyses used to quantify intraspecies variation at the genome level are the average nucleotide identity (ani), which detects the dna conservation of the core genome, and the dna content, which calculates the proportion of dna share ... | 2009 | 18978054 |
| pseudomonas genome database: facilitating user-friendly, comprehensive comparisons of microbial genomes. | pseudomonas aeruginosa is a well-studied opportunistic pathogen that is particularly known for its intrinsic antimicrobial resistance, diverse metabolic capacity, and its ability to cause life threatening infections in cystic fibrosis patients. the pseudomonas genome database (http://www.pseudomonas.com) was originally developed as a resource for peer-reviewed, continually updated annotation for the pseudomonas aeruginosa pao1 reference strain genome. in order to facilitate cross-strain and cros ... | 2009 | 18978025 |
| pseudomonas genome database: facilitating user-friendly, comprehensive comparisons of microbial genomes. | pseudomonas aeruginosa is a well-studied opportunistic pathogen that is particularly known for its intrinsic antimicrobial resistance, diverse metabolic capacity, and its ability to cause life threatening infections in cystic fibrosis patients. the pseudomonas genome database (http://www.pseudomonas.com) was originally developed as a resource for peer-reviewed, continually updated annotation for the pseudomonas aeruginosa pao1 reference strain genome. in order to facilitate cross-strain and cros ... | 2009 | 18978025 |
| direct identification of the meloidogyne incognita secretome reveals proteins with host cell reprogramming potential. | the root knot nematode, meloidogyne incognita, is an obligate parasite that causes significant damage to a broad range of host plants. infection is associated with secretion of proteins surrounded by proliferating cells. many parasites are known to secrete effectors that interfere with plant innate immunity, enabling infection to occur; they can also release pathogen-associated molecular patterns (pamps, e.g., flagellin) that trigger basal immunity through the nematode stylet into the plant cell ... | 2008 | 18974830 |
| temporal control of message stability in the life cycle of double-stranded rna bacteriophage phi8. | the cystoviruses have genomes of three double-stranded rna segments. the genes of the l transcript are expressed early in infection, while those of m and s are expressed late. in all cystovirus groups but one, the quantity of the l transcript late in infection is lower than those of the other two because of transcriptional control. in bacteriophage phi8 and its close relatives, transcription of l is not controlled; instead, the l transcript is turned over rapidly late in infection. the three mes ... | 2008 | 18971268 |
| temporal control of message stability in the life cycle of double-stranded rna bacteriophage phi8. | the cystoviruses have genomes of three double-stranded rna segments. the genes of the l transcript are expressed early in infection, while those of m and s are expressed late. in all cystovirus groups but one, the quantity of the l transcript late in infection is lower than those of the other two because of transcriptional control. in bacteriophage phi8 and its close relatives, transcription of l is not controlled; instead, the l transcript is turned over rapidly late in infection. the three mes ... | 2008 | 18971268 |
| identification of an isr-related metabolite produced by pseudomonas chlororaphis o6 against the wildfire pathogen pseudomonas syringae pv.tabaci in tobacco. | pseudomonas chlororaphis o6 exhibits induced systemic resistance (isr) against p. syringae pv. tabaci in tobacco. to identify one of the isr metabolites, o6 cultures were extracted with organic solvents, and the organic extracts were subjected to column chromatography followed by spectroscopy analyses. the isr bioassay-guided fractionation was carried out for isolation of the metabolite. highresolution mass spectrometric analysis of the metabolite found c(9)h(9)o(3)n with an exact mass of 179.05 ... | 2008 | 18955815 |
| using mahalanobis distance to compare genomic signatures between bacterial plasmids and chromosomes. | plasmids are ubiquitous mobile elements that serve as a pool of many host beneficial traits such as antibiotic resistance in bacterial communities. to understand the importance of plasmids in horizontal gene transfer, we need to gain insight into the 'evolutionary history' of these plasmids, i.e. the range of hosts in which they have evolved. since extensive data support the proposal that foreign dna acquires the host's nucleotide composition during long-term residence, comparison of nucleotide ... | 2008 | 18953039 |
| stress-induced cell death is mediated by ceramide synthesis in neurospora crassa. | the combined stresses of moderate heat shock (45 degrees c) and analog-induced glucose deprivation constitute a lethal stress for neurospora crassa. we found that this cell death requires fatty acid synthesis and the cofactor biotin. in the absence of the cofactor, the stressed cells are particularly sensitive to exogenous ceramide, which is lethal at low concentrations. when we extracted endogenous sphingolipids, we found that unique ceramides were induced (i) by the inhibitory glucose analog 2 ... | 2008 | 18952903 |
| development of an autofluorescent whole-cell biocatalyst by displaying dual functional moieties on escherichia coli cell surfaces and construction of a coculture with organophosphate-mineralizing activity . | surface display of the active proteins on living cells has enormous potential in the degradation of numerous toxic compounds. here, we report the codisplay of organophosphorus hydrolase (oph) and enhanced green fluorescent protein (gfp) on the cell surface of escherichia coli by use of the truncated ice nucleation protein (inpnc) and lpp-ompa fusion systems. the surface localization of both inpnc-oph and lpp-ompa-gfp was demonstrated by western blot analysis, immunofluorescence microscopy, and a ... | 2008 | 18952884 |
| in silico analysis of methyltransferase domains involved in biosynthesis of secondary metabolites. | secondary metabolites biosynthesized by polyketide synthase (pks) and nonribosomal peptide synthetase (nrps) family of enzymes constitute several classes of therapeutically important natural products like erythromycin, rapamycin, cyclosporine etc. in view of their relevance for natural product based drug discovery, identification of novel secondary metabolite natural products by genome mining has been an area of active research. a number of different tailoring enzymes catalyze a variety of chemi ... | 2008 | 18950525 |
| host-plant-mediated effects of nadefensin on herbivore and pathogen resistance in nicotiana attenuata. | the adage from shakespeare, "troubles, not as single spies, but in battalions come," holds true for nicotiana attenuata, which is commonly attacked by both pathogens (pseudomonas spp.) and herbivores (manduca sexta) in its native habitats. defense responses targeted against the pathogens can directly or indirectly influence the responses against the herbivores. nadefensin is an effective induced defense gene against the bacterial pathogen pseudomonas syringae pv tomato (pst dc3000), which is als ... | 2008 | 18950524 |
| life history determines genetic structure and evolutionary potential of host-parasite interactions. | measures of population genetic structure and diversity of disease-causing organisms are commonly used to draw inferences regarding their evolutionary history and potential to generate new variation in traits that determine interactions with their hosts. parasite species exhibit a range of population structures and life-history strategies, including different transmission modes, life-cycle complexity, off-host survival mechanisms and dispersal ability. these are important determinants of the freq ... | 2008 | 18947899 |