Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| quantitative detection of the nosz gene, encoding nitrous oxide reductase, and comparison of the abundances of 16s rrna, narg, nirk, and nosz genes in soils. | nitrous oxide (n2o) is an important greenhouse gas in the troposphere controlling ozone concentration in the stratosphere through nitric oxide production. in order to quantify bacteria capable of n2o reduction, we developed a sybr green quantitative real-time pcr assay targeting the nosz gene encoding the catalytic subunit of the nitrous oxide reductase. two independent sets of nosz primers flanking the nosz fragment previously used in diversity studies were designed and tested (k. kloos, a. mer ... | 2006 | 16885263 |
| protein-translocating trimeric autotransporters of gram-negative bacteria. | 2006 | 16885434 | |
| characterization of the mrgrs locus of the opportunistic pathogen burkholderia pseudomallei: temperature regulates the expression of a two-component signal transduction system. | burkholderia pseudomallei is a saprophyte in tropical environments and an opportunistic human pathogen. this versatility requires a sensing mechanism that allows the bacterium to respond rapidly to altered environmental conditions. we characterized a two-component signal transduction locus from b. pseudomallei 204, mrgr and mrgs, encoding products with extensive homology with response regulators and histidine protein kinases of escherichia coli, bordetella pertussis, and vibrio cholerae. | 2006 | 16893462 |
| mutations in the lrpe gene of ralstonia solanacearum affects hrp pili production and virulence. | the ralstonia solanacearum hrpb-regulated gene lrpe (hpx5/brg24) encodes a popc-like leucine-rich repeat (lrr) protein that carries 11 tandem lrr in the central region. defects in the lrpe gene slightly reduced the virulence of r. solanacearum on host plants and changed the bacterial morphology leading to the formation of large aggregates in a minimal medium. the aggregation in the deltalrpe background required the presence of a functional hrp type iii secretion system. in wild-type r. solanacea ... | 2006 | 16903354 |
| pseudomonas syringae hrpj is a type iii secreted protein that is required for plant pathogenesis, injection of effectors, and secretion of the hrpz1 harpin. | the bacterial plant pathogen pseudomonas syringae requires a type iii protein secretion system (ttss) to cause disease. the p. syringae ttss is encoded by the hrp-hrc gene cluster. one of the genes within this cluster, hrpj, encodes a protein with weak similarity to yopn, a type iii secreted protein from the animal pathogenic yersinia species. here, we show that hrpj is secreted in culture and translocated into plant cells by the p. syringae pv. tomato dc3000 ttss. a dc3000 hrpj mutant, unl140, ... | 2006 | 16923873 |
| the structure of mbti from mycobacterium tuberculosis, the first enzyme in the biosynthesis of the siderophore mycobactin, reveals it to be a salicylate synthase. | the ability to acquire iron from the extracellular environment is a key determinant of pathogenicity in mycobacteria. mycobacterium tuberculosis acquires iron exclusively via the siderophore mycobactin t, the biosynthesis of which depends on the production of salicylate from chorismate. salicylate production in other bacteria is either a two-step process involving an isochorismate synthase (chorismate isomerase) and a pyruvate lyase, as observed for pseudomonas aeruginosa, or a single-step conve ... | 2006 | 16923875 |
| evolution of vitamin b2 biosynthesis: 6,7-dimethyl-8-ribityllumazine synthases of brucella. | the penultimate step in the biosynthesis of riboflavin (vitamin b2) involves the condensation of 3,4-dihydroxy-2-butanone 4-phosphate with 5-amino-6-ribitylamino-2,4(1h,3h)-pyrimidinedione, which is catalyzed by 6,7-dimethyl-8-ribityllumazine synthase (lumazine synthase). pathogenic brucella species adapted to an intracellular lifestyle have two genes involved in riboflavin synthesis, ribh1 and ribh2, which are located on different chromosomes. the ribh2 gene was shown previously to specify a lu ... | 2006 | 16923880 |
| residues involved in fecr binding are localized on one side of the feca signaling domain in escherichia coli. | ferric citrate transport in escherichia coli involves proteins encoded by the fec genes, including the transport and signaling protein feca and the signal transducing protein fecr. randomly isolated feca point mutants showed a reduced interaction with fecr and a reduced transcription initiation of the ferric citrate transport genes. the mutations were localized on one side of the feca signaling domain, which might form the interface to fecr. some of the mutants showed strongly reduced iron trans ... | 2006 | 16923915 |
| exopolysaccharide-associated protein sorting in environmental organisms: the pep-cterm/epsh system. application of a novel phylogenetic profiling heuristic. | protein translocation to the proper cellular destination may be guided by various classes of sorting signals recognizable in the primary sequence. detection in some genomes, but not others, may reveal sorting system components by comparison of the phylogenetic profile of the class of sorting signal to that of various protein families. | 2006 | 16930487 |
| integrated regulation of the type iii secretion system and other virulence determinants in ralstonia solanacearum. | in many plant and animal bacterial pathogens, the type iii secretion system (ttss) that directly translocates effector proteins into the eukaryotic host cells is essential for the development of disease. in all species studied, the transcription of the ttss and most of its effector substrates is tightly regulated by a succession of consecutively activated regulators. however, the whole genetic programme driven by these regulatory cascades is still unknown, especially in bacterial plant pathogens ... | 2006 | 16933989 |
| specific binding of the xanthomonas campestris pv. vesicatoria arac-type transcriptional activator hrpx to plant-inducible promoter boxes. | the pathogenicity of the plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria depends on a type iii secretion system which is encoded by the 23-kb hrp (hypersensitive response and pathogenicity) gene cluster. expression of the hrp operons is strongly induced in planta and in a special minimal medium and depends on two regulatory proteins, hrpg and hrpx. in this study, dna affinity enrichment was used to demonstrate that the arac-type transcriptional activator hrpx binds to a conserv ... | 2006 | 16936021 |
| 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 |
| the barley erf-type transcription factor hvraf confers enhanced pathogen resistance and salt tolerance in arabidopsis. | we isolated hvraf (hordeum vulgare root abundant factor), a cdna encoding a novel ethylene response factor (erf)-type transcription factor, from young seedlings of barley. in addition to the most highly conserved apetala2/erf dna-binding domain, the encoded protein contained an n-terminal mcggail signature sequence, a putative nuclear localization sequence, and a c-terminal acidic transcription activation domain containing a novel mammalian hemopexin domain signature-like sequence. their homolog ... | 2007 | 16937017 |
| elucidation of the hrp clusters of xanthomonas oryzae pv. oryzicola that control the hypersensitive response in nonhost tobacco and pathogenicity in susceptible host rice. | xanthomonas oryzae pv. oryzicola, the cause of bacterial leaf streak in rice, possesses clusters of hrp genes that determine its ability to elicit a hypersensitive response (hr) in nonhost tobacco and pathogenicity in host rice. a 27-kb region of the genome of x. oryzae pv. oryzicola (rs105) was identified and sequenced, revealing 10 hrp, 9 hrc (hrp conserved), and 8 hpa (hrp-associated) genes and 7 regulatory plant-inducible promoter boxes. while the region from hpa2 to hpab and the hrpf operon ... | 2006 | 16957248 |
| genotypic diversity in a localized population of ralstonia solanacearum as revealed by random amplified polymorphic dna markers. | to assess genotypic diversity within ralstonia solanacearum isolates of a single field. | 2006 | 16968291 |
| 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 |
| pirin regulates pyruvate catabolism by interacting with the pyruvate dehydrogenase e1 subunit and modulating pyruvate dehydrogenase activity. | the protein pirin, which is involved in a variety of biological processes, is conserved from prokaryotic microorganisms, fungi, and plants to mammals. it acts as a transcriptional cofactor or an apoptosis-related protein in mammals and is involved in seed germination and seedling development in plants. in prokaryotes, while pirin is stress induced in cyanobacteria and may act as a quercetinase in escherichia coli, the functions of pirin orthologs remain mostly uncharacterized. we show that the s ... | 2007 | 16980458 |
| pirin regulates pyruvate catabolism by interacting with the pyruvate dehydrogenase e1 subunit and modulating pyruvate dehydrogenase activity. | the protein pirin, which is involved in a variety of biological processes, is conserved from prokaryotic microorganisms, fungi, and plants to mammals. it acts as a transcriptional cofactor or an apoptosis-related protein in mammals and is involved in seed germination and seedling development in plants. in prokaryotes, while pirin is stress induced in cyanobacteria and may act as a quercetinase in escherichia coli, the functions of pirin orthologs remain mostly uncharacterized. we show that the s ... | 2007 | 16980458 |
| ralstonia solanacearum requires f-box-like domain-containing type iii effectors to promote disease on several host plants. | the phytopathogenic bacterium ralstonia solanacearum encodes a family of seven type iii secretion system (t3ss) effectors that contain both a leucine-rich repeat and an f-box domain. this structure is reminiscent of a class of typical eukaryotic proteins called f-box proteins. the latter, together with skp1 and cullin1 subunits, constitute the scf-type e3 ubiquitin ligase complex and control specific protein ubiquitinylation. in the eukaryotic cell, depending on the nature of the polyubiquitin c ... | 2006 | 16983093 |
| burkholderia xenovorans lb400 harbors a multi-replicon, 9.73-mbp genome shaped for versatility. | burkholderia xenovorans lb400 (lb400), a well studied, effective polychlorinated biphenyl-degrader, has one of the two largest known bacterial genomes and is the first nonpathogenic burkholderia isolate sequenced. from an evolutionary perspective, we find significant differences in functional specialization between the three replicons of lb400, as well as a more relaxed selective pressure for genes located on the two smaller vs. the largest replicon. high genomic plasticity, diversity, and speci ... | 2006 | 17030797 |
| kinase activity of overexpressed hipa is required for growth arrest and multidrug tolerance in escherichia coli. | overexpression of the hipa protein of the hipba toxin/antitoxin module leads to multidrug tolerance in escherichia coli. hipa is a "toxin" that causes reversible dormancy, whereas hipb is an antitoxin that binds hipa and acts as a transcriptional repressor of the hipba operon. comparative sequence analysis shows that hipa is a member of the phosphatidylinositol 3/4-kinase superfamily. the kinase activity of hipa was examined. hipa was autophosphorylated in the presence of atp in vitro, and the p ... | 2006 | 17041039 |
| the effect of the chemical, biological, and physical environment on quorum sensing in structured microbial communities. | as researchers attempt to study quorum sensing in relevant clinical or environmental settings, it is apparent that many factors have the potential to affect signaling. these factors span a range of physical, chemical, and biological variables that can impact signal production, stability and distribution. optimizing experimental systems to natural or clinical environments may be crucial for defining when and where quorum sensing occurs. these points are illustrated in our case study of s. aureus ... | 2006 | 17047948 |
| the effect of the chemical, biological, and physical environment on quorum sensing in structured microbial communities. | as researchers attempt to study quorum sensing in relevant clinical or environmental settings, it is apparent that many factors have the potential to affect signaling. these factors span a range of physical, chemical, and biological variables that can impact signal production, stability and distribution. optimizing experimental systems to natural or clinical environments may be crucial for defining when and where quorum sensing occurs. these points are illustrated in our case study of s. aureus ... | 2006 | 17047948 |
| an inventory of yeast proteins associated with nucleolar and ribosomal components. | although baker's yeast is a primary model organism for research on eukaryotic ribosome assembly and nucleoli, the list of its proteins that are functionally associated with nucleoli or ribosomes is still incomplete. we trained a naïve bayesian classifier to predict novel proteins that are associated with yeast nucleoli or ribosomes based on parts lists of nucleoli in model organisms and large-scale protein interaction data sets. phylogenetic profiling and gene expression analysis were carried ou ... | 2006 | 17067374 |
| the rpot regulon of pseudomonas putida dot-t1e and its role in stress endurance against solvents. | pseudomonas putida encodes 20 extracytoplasmic sigma factors (ecfs). in this study, we show that one of these ecfs, known as ecf-pp12 (pp3006), plays a role in tolerance of toluene and other organic solvents. based on this finding, we have called the gene that encodes this new ecf rpot. the rpot gene forms an operon with the preceding gene and with the gene located downstream. the translated gene product of the open reading frame pp3005 is an inner membrane protein, whereas the pp3007 protein is ... | 2007 | 17071759 |
| the rpot regulon of pseudomonas putida dot-t1e and its role in stress endurance against solvents. | pseudomonas putida encodes 20 extracytoplasmic sigma factors (ecfs). in this study, we show that one of these ecfs, known as ecf-pp12 (pp3006), plays a role in tolerance of toluene and other organic solvents. based on this finding, we have called the gene that encodes this new ecf rpot. the rpot gene forms an operon with the preceding gene and with the gene located downstream. the translated gene product of the open reading frame pp3005 is an inner membrane protein, whereas the pp3007 protein is ... | 2007 | 17071759 |
| regulation of the type iii secretion system in phytopathogenic bacteria. | the type iii secretion system (ttss) is a specialized protein secretion machinery used by numerous gram-negative bacterial pathogens of animals and plants to deliver effector proteins directly into the host cells. in plant-pathogenic bacteria, genes encoding the ttss were discovered as hypersensitive response and pathogenicity (hrp) genes, because mutation of these genes typically disrupts the bacterial ability to cause diseases on host plants and to elicit hypersensitive response on nonhost pla ... | 2006 | 17073299 |
| the evolution of two-component systems in bacteria reveals different strategies for niche adaptation. | two-component systems including histidine protein kinases represent the primary signal transduction paradigm in prokaryotic organisms. to understand how these systems adapt to allow organisms to detect niche-specific signals, we analyzed the phylogenetic distribution of nearly 5,000 histidine protein kinases from 207 sequenced prokaryotic genomes. we found that many genomes carry a large repertoire of recently evolved signaling genes, which may reflect selective pressure to adapt to new environm ... | 2006 | 17083272 |
| 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 |
| glycosylation of pseudomonas aeruginosa strain pa5196 type iv pilins with mycobacterium-like alpha-1,5-linked d-araf oligosaccharides. | pseudomonas aeruginosa is a gram-negative bacterium that uses polar type iv pili for adherence to various materials and for rapid colonization of surfaces via twitching motility. within the p. aeruginosa species, five distinct alleles encoding variants of the structural subunit pila varying in amino acid sequence, length, and presence of posttranslational modifications have been identified. in this work, a combination of mass spectrometry and nuclear magnetic resonance spectroscopy was used to i ... | 2007 | 17085575 |
| glycosylation of pseudomonas aeruginosa strain pa5196 type iv pilins with mycobacterium-like alpha-1,5-linked d-araf oligosaccharides. | pseudomonas aeruginosa is a gram-negative bacterium that uses polar type iv pili for adherence to various materials and for rapid colonization of surfaces via twitching motility. within the p. aeruginosa species, five distinct alleles encoding variants of the structural subunit pila varying in amino acid sequence, length, and presence of posttranslational modifications have been identified. in this work, a combination of mass spectrometry and nuclear magnetic resonance spectroscopy was used to i ... | 2007 | 17085575 |
| dynamic state of dna topology is essential for genome condensation in bacteria. | in bacteria, dps is one of the critical proteins to build up a condensed nucleoid in response to the environmental stresses. in this study, we found that the expression of dps and the nucleoid condensation was not simply correlated in escherichia coli, and that fis, which is an e. coli (gamma-proteobacteria)-specific nucleoid protein, interfered with the dps-dependent nucleoid condensation. atomic force microscopy and northern blot analyses indicated that the inhibitory effect of fis was due to ... | 2006 | 17093499 |
| selection for unequal densities of sigma70 promoter-like signals in different regions of large bacterial genomes. | the evolutionary processes operating in the dna regions that participate in the regulation of gene expression are poorly understood. in escherichia coli, we have established a sequence pattern that distinguishes regulatory from nonregulatory regions. the density of promoter-like sequences, that could be recognizable by rna polymerase and may function as potential promoters, is high within regulatory regions, in contrast to coding regions and regions located between convergently transcribed genes ... | 2006 | 17096598 |
| plant nbs-lrr proteins in pathogen sensing and host defense. | plant proteins belonging to the nucleotide-binding site-leucine-rich repeat (nbs-lrr) family are used for pathogen detection. like the mammalian nod-lrr protein 'sensors' that detect intracellular conserved pathogen-associated molecular patterns, plant nbs-lrr proteins detect pathogen-associated proteins, most often the effector molecules of pathogens responsible for virulence. many virulence proteins are detected indirectly by plant nbs-lrr proteins from modifications the virulence proteins inf ... | 2006 | 17110940 |
| functional analysis of burkholderia cepacia genes bced and bcef, encoding a phosphotyrosine phosphatase and a tyrosine autokinase, respectively: role in exopolysaccharide biosynthesis and biofilm formation. | the biosynthesis of the exopolysaccharide (eps) cepacian by burkholderia cepacia complex strains requires the 16.2-kb bce cluster of genes. two of the clustered genes, bced and bcef, code for two proteins homologous to phosphotyrosine phosphatases and tyrosine kinases, respectively. we show experimental evidence indicating that bcef is phosphorylated on tyrosine and that the conserved lysine residue present at position 563 in the walker a atp-binding motif is required for this autophosphorylatio ... | 2007 | 17114319 |
| functional analysis of burkholderia cepacia genes bced and bcef, encoding a phosphotyrosine phosphatase and a tyrosine autokinase, respectively: role in exopolysaccharide biosynthesis and biofilm formation. | the biosynthesis of the exopolysaccharide (eps) cepacian by burkholderia cepacia complex strains requires the 16.2-kb bce cluster of genes. two of the clustered genes, bced and bcef, code for two proteins homologous to phosphotyrosine phosphatases and tyrosine kinases, respectively. we show experimental evidence indicating that bcef is phosphorylated on tyrosine and that the conserved lysine residue present at position 563 in the walker a atp-binding motif is required for this autophosphorylatio ... | 2007 | 17114319 |
| the transcription factors wrky11 and wrky17 act as negative regulators of basal resistance in arabidopsis thaliana. | transcription factors are believed to play a pivotal role in the activation and fine-tuning of plant defense responses, but little is known about the exact function of individual transcription factors in this process. we analyzed the role of the iid subfamily of wrky transcription factors in the regulation of basal resistance to pseudomonas syringae pv tomato (pst). the expression of four members of the subfamily was induced upon challenge with virulent and avirulent strains of pst. mutant analy ... | 2006 | 17114354 |
| dissecting the wrky web of plant defense regulators. | 2006 | 17121464 | |
| protein homology network families reveal step-wise diversification of type iii and type iv secretion systems. | from the analysis of 251 prokaryotic genomes stored in public databases, the 761,260 deduced proteins were used to reconstruct a complete set of bacterial proteic families. using the new overlap algorithm, we have partitioned the protein homology network (phn), where the proteins are the nodes and the links represent homology relationships. the algorithm identifies the densely connected regions of the phn that define the families of homologous proteins, here called phn-families, recognizing the ... | 2006 | 17140285 |
| coverage of whole proteome by structural genomics observed through protein homology modeling database. | we have been developing famsbase, a protein homology-modeling database of whole orfs predicted from genome sequences. the latest update of famsbase ( http://daisy.nagahama-i-bio.ac.jp/famsbase/ ), which is based on the protein three-dimensional (3d) structures released by november 2003, contains modeled 3d structures for 368,724 open reading frames (orfs) derived from genomes of 276 species, namely 17 archaebacterial, 130 eubacterial, 18 eukaryotic and 111 phage genomes. those 276 genomes are pr ... | 2006 | 17146617 |
| expression of a novel small antimicrobial protein from the seeds of motherwort (leonurus japonicus) confers disease resistance in tobacco. | medicinal plants are valuable resources of natural antimicrobial materials. a novel small protein with antimicrobial activities, designated ljamp1, was purified from the seeds of a medicinal herb, motherwort (leonurus japonicus houtt). ljamp1 is a heat-stable protein with a molecular mass of 7.8 kda and a determined isoelectric point of 8.2. in vitro assays showed that ljamp1 inhibits the growth of an array of fungi and bacteria. the hyphal growth inhibition by ljamp1 was more evident against hy ... | 2007 | 17158620 |
| 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 |
| whole-genome analysis of the methyl tert-butyl ether-degrading beta-proteobacterium methylibium petroleiphilum pm1. | methylibium petroleiphilum pm1 is a methylotroph distinguished by its ability to completely metabolize the fuel oxygenate methyl tert-butyl ether (mtbe). strain pm1 also degrades aromatic (benzene, toluene, and xylene) and straight-chain (c(5) to c(12)) hydrocarbons present in petroleum products. whole-genome analysis of pm1 revealed an approximately 4-mb circular chromosome and an approximately 600-kb megaplasmid, containing 3,831 and 646 genes, respectively. aromatic hydrocarbon and alkane deg ... | 2007 | 17158667 |
| whole-genome analysis of the methyl tert-butyl ether-degrading beta-proteobacterium methylibium petroleiphilum pm1. | methylibium petroleiphilum pm1 is a methylotroph distinguished by its ability to completely metabolize the fuel oxygenate methyl tert-butyl ether (mtbe). strain pm1 also degrades aromatic (benzene, toluene, and xylene) and straight-chain (c(5) to c(12)) hydrocarbons present in petroleum products. whole-genome analysis of pm1 revealed an approximately 4-mb circular chromosome and an approximately 600-kb megaplasmid, containing 3,831 and 646 genes, respectively. aromatic hydrocarbon and alkane deg ... | 2007 | 17158667 |
| stimulus perception in bacterial signal-transducing histidine kinases. | two-component signal-transducing systems are ubiquitously distributed communication interfaces in bacteria. they consist of a histidine kinase that senses a specific environmental stimulus and a cognate response regulator that mediates the cellular response, mostly through differential expression of target genes. histidine kinases are typically transmembrane proteins harboring at least two domains: an input (or sensor) domain and a cytoplasmic transmitter (or kinase) domain. they can be identifi ... | 2006 | 17158704 |
| transcriptional activator tsrf1 reversely regulates pathogen resistance and osmotic stress tolerance in tobacco. | increasing evidences show that ethylene-responsive factor (erf) proteins regulate plant stress response and the interaction of different stress responsive pathways through interacting with different cis-acting elements, even other transcription factors. here, we report a transcriptional activator tsrf1, which was previously demonstrated to regulate plant resistance to ralstonia solanacearum, reversely regulates pathogen resistance and osmotic stress tolerance in tobacco. sequence analysis reveal ... | 2007 | 17160455 |
| 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 mi-9 gene from solanum arcanum conferring heat-stable resistance to root-knot nematodes is a homolog of mi-1. | resistance conferred by the mi-1 gene from solanum peruvianum is effective and widely used for limiting root-knot nematode (meloidogyne spp.) yield loss in tomato (solanum lycopersicum), but the resistance is ineffective at soil temperatures above 28 degrees c. previously, we mapped the heat-stable resistance gene mi-9 in solanum arcanum accession la2157 to the short arm of chromosome 6, in a genetic interval as mi-1 and the cladosporium fulvum resistance gene cf2. we developed a fine map of the ... | 2007 | 17172289 |
| capa, an autotransporter protein of campylobacter jejuni, mediates association with human epithelial cells and colonization of the chicken gut. | two putative autotransporter proteins, capa and capb, were identified in silico from the genome sequence of campylobacter jejuni nctc11168. the genes encoding each protein contain homopolymeric tracts, suggestive of phase variation mediated by a slipped-strand mispairing mechanism; in each case the gene sequence contained frameshifts at these positions. the c-terminal two-thirds of the two genes, as well as a portion of the predicted signal peptides, were identical; the remaining n-terminal port ... | 2007 | 17172331 |
| capa, an autotransporter protein of campylobacter jejuni, mediates association with human epithelial cells and colonization of the chicken gut. | two putative autotransporter proteins, capa and capb, were identified in silico from the genome sequence of campylobacter jejuni nctc11168. the genes encoding each protein contain homopolymeric tracts, suggestive of phase variation mediated by a slipped-strand mispairing mechanism; in each case the gene sequence contained frameshifts at these positions. the c-terminal two-thirds of the two genes, as well as a portion of the predicted signal peptides, were identical; the remaining n-terminal port ... | 2007 | 17172331 |
| the sphingomonas plasmid pcar3 is involved in complete mineralization of carbazole. | we determined the complete 254,797-bp nucleotide sequence of the plasmid pcar3, a carbazole-degradative plasmid from sphingomonas sp. strain ka1. a region of about 65 kb involved in replication and conjugative transfer showed similarity to a region of plasmid pnl1 isolated from the aromatic-degrading novosphingobium aromaticivorans strain f199. the presence of many insertion sequences, transposons, repeat sequences, and their remnants suggest plasticity of this plasmid in genetic structure. alth ... | 2007 | 17172338 |
| the sphingomonas plasmid pcar3 is involved in complete mineralization of carbazole. | we determined the complete 254,797-bp nucleotide sequence of the plasmid pcar3, a carbazole-degradative plasmid from sphingomonas sp. strain ka1. a region of about 65 kb involved in replication and conjugative transfer showed similarity to a region of plasmid pnl1 isolated from the aromatic-degrading novosphingobium aromaticivorans strain f199. the presence of many insertion sequences, transposons, repeat sequences, and their remnants suggest plasticity of this plasmid in genetic structure. alth ... | 2007 | 17172338 |
| insights on the evolution of trehalose biosynthesis. | the compatible solute trehalose is a non-reducing disaccharide, which accumulates upon heat, cold or osmotic stress. it was commonly accepted that trehalose is only present in extremophiles or cryptobiotic organisms. however, in recent years it has been shown that although higher plants do not accumulate trehalose at significant levels they have actively transcribed genes encoding the corresponding biosynthetic enzymes. | 2006 | 17178000 |
| development of signature-tagged mutagenesis in burkholderia pseudomallei to identify genes important in survival and pathogenesis. | burkholderia pseudomallei, the causative agent of melioidosis, is an important human pathogen in southeast asia and northern australia for which a vaccine is unavailable. a panel of 892 double signature-tagged mutants was screened for virulence using an intranasal balb/c mouse model of infection. a novel dna tag microarray identified 33 mutants as being attenuated in spleens, while 6 were attenuated in both lungs and spleens. the transposon insertion sites in spleen-attenuated mutants revealed g ... | 2007 | 17189432 |
| development of signature-tagged mutagenesis in burkholderia pseudomallei to identify genes important in survival and pathogenesis. | burkholderia pseudomallei, the causative agent of melioidosis, is an important human pathogen in southeast asia and northern australia for which a vaccine is unavailable. a panel of 892 double signature-tagged mutants was screened for virulence using an intranasal balb/c mouse model of infection. a novel dna tag microarray identified 33 mutants as being attenuated in spleens, while 6 were attenuated in both lungs and spleens. the transposon insertion sites in spleen-attenuated mutants revealed g ... | 2007 | 17189432 |
| evolutionary dynamics of ralstonia solanacearum. | we investigated the genetic diversity, extent of recombination, natural selection, and population divergence of ralstonia solanacearum samples obtained from sources worldwide. this plant pathogen causes bacterial wilt in many crops and constitutes a serious threat to agricultural production due to its very wide host range and aggressiveness. five housekeeping genes, dispersed around the chromosome, and three virulence-related genes, located on the megaplasmid, were sequenced from 58 strains belo ... | 2007 | 17189443 |
| evolutionary dynamics of ralstonia solanacearum. | we investigated the genetic diversity, extent of recombination, natural selection, and population divergence of ralstonia solanacearum samples obtained from sources worldwide. this plant pathogen causes bacterial wilt in many crops and constitutes a serious threat to agricultural production due to its very wide host range and aggressiveness. five housekeeping genes, dispersed around the chromosome, and three virulence-related genes, located on the megaplasmid, were sequenced from 58 strains belo ... | 2007 | 17189443 |
| type iii effector diversification via both pathoadaptation and horizontal transfer in response to a coevolutionary arms race. | the concept of the coevolutionary arms race holds a central position in our understanding of pathogen-host interactions. here we identify the molecular mechanisms and follow the stepwise progression of an arms race in a natural system. we show how the evolution and function of the hopz family of type iii secreted effector proteins carried by the plant pathogen pseudomonas syringae are influenced by a coevolutionary arms race between pathogen and host. we surveyed 96 isolates of p. syringae and i ... | 2006 | 17194219 |
| natural variation in partial resistance to pseudomonas syringae is controlled by two major qtls in arabidopsis thaliana. | low-level, partial resistance is pre-eminent in natural populations, however, the mechanisms underlying this form of resistance are still poorly understood. | 2006 | 17205127 |
| phylogenetic tree information aids supervised learning for predicting protein-protein interaction based on distance matrices. | protein-protein interactions are critical for cellular functions. recently developed computational approaches for predicting protein-protein interactions utilize co-evolutionary information of the interacting partners, e.g., correlations between distance matrices, where each matrix stores the pairwise distances between a protein and its orthologs from a group of reference genomes. | 2007 | 17212819 |
| 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 |
| genetics and expression of the carbapenem-hydrolyzing oxacillinase gene blaoxa-23 in acinetobacter baumannii. | the genetic structures surrounding the plasmid-carried blaoxa-23 oxacillinase gene, encoding resistance to carbapenems, were studied in acinetobacter baumannii. isaba1 and the novel element isaba4 were detected upstream of the blaoxa-23 gene, providing promoter sequences for its expression. these insertion elements were likely involved in transposition processes at the origin of acquisition of this beta-lactamase gene. | 2007 | 17220422 |
| identifying bacterial genes and endosymbiont dna with glimmer. | the glimmer gene-finding software has been successfully used for finding genes in bacteria, archaea and viruses representing hundreds of species. we describe several major changes to the glimmer system, including improved methods for identifying both coding regions and start codons. we also describe a new module of glimmer that can distinguish host and endosymbiont dna. this module was developed in response to the discovery that eukaryotic genome sequencing projects sometimes inadvertently captu ... | 2007 | 17237039 |
| chromosome-encoded narrow-spectrum ambler class a beta-lactamase gil-1 from citrobacter gillenii. | a novel beta-lactamase gene was cloned from the whole-cell dna of an enterobacterial citrobacter gillenii reference strain that displayed a weak narrow-spectrum beta-lactam-resistant phenotype and was expressed in escherichia coli. it encoded a clavulanic acid-inhibited ambler class a beta-lactamase, gil-1, with a pi value of 7.5 and a molecular mass of ca. 29 kda. gil-1 had the highest percent amino acid sequence identity with tem-1 and shv-1, 77%, and 67%, respectively, and only 46%, 31%, and ... | 2007 | 17242148 |
| pathogen-induced calmodulin isoforms in basal resistance against bacterial and fungal pathogens in tobacco. | thirteen tobacco calmodulin (cam) genes fall into three distinct amino acid homology types. wound-inducible type i isoforms ntcam1 and 2 were moderately induced by tobacco mosaic virus (tmv)-mediated hypersensitive reaction, and the type iii isoform ntcam13 was highly induced, while the type ii isoforms ntcam3-ntcam12 showed little response. type i and iii knockdown tobacco lines were generated using inverted repeat sequences from ntcam1 and 13, respectively, to evaluate the contribution of path ... | 2007 | 17251204 |
| exploitation of eukaryotic ubiquitin signaling pathways by effectors translocated by bacterial type iii and type iv secretion systems. | the specific and covalent addition of ubiquitin to proteins, known as ubiquitination, is a eukaryotic-specific modification central to many cellular processes, such as cell cycle progression, transcriptional regulation, and hormone signaling. polyubiquitination is a signal for the 26s proteasome to destroy earmarked proteins, but depending on the polyubiquitin chain topology, it can also result in new protein properties. both ubiquitin-orchestrated protein degradation and modification have also ... | 2007 | 17257058 |
| 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 |
| prevalence of shiga toxin-producing escherichia coli stx1, stx2, eaea, and rfbe genes and survival of e. coli o157:h7 in manure from organic and low-input conventional dairy farms. | manure samples were collected from 16 organic (org) and 9 low-input conventional (lic) dutch dairy farms during august and september 2004 to determine the prevalence of the stec virulence genes stx(1) (encoding shiga toxin 1), stx(2) (encoding shiga toxin 2), and eaea (encoding intimin), as well as the rfbe gene, which is specific for escherichia coli o157. the rfbe gene was present at 52% of the farms. the prevalence of rfbe was higher at org farms (61%) than at lic farms (36%), but this was no ... | 2007 | 17277204 |
| phylogenetic signal and functional categories in proteobacteria genomes. | a comprehensive evolutionary analysis of bacterial genomes implies to identify the hallmark of vertical and non-vertical signals and to discriminate them from the presence of mere phylogenetic noise. in this report we have addressed the impact of factors like the universal distribution of the genes, their essentiality or their functional role in the cell on the inference of vertical signal through phylogenomic methods. | 2007 | 17288580 |
| a conserved carboxylesterase is a suppressor of avrbst-elicited resistance in arabidopsis. | avrbst is a type iii effector from xanthomonas campestris pv vesicatoria that is translocated into plant cells during infection. avrbst is predicted to encode a cys protease that targets intracellular host proteins. to dissect avrbst function and recognition in arabidopsis thaliana, 71 ecotypes were screened to identify lines that elicit an avrbst-dependent hypersensitive response (hr) after xanthomonas campestris pv campestris (xcc) infection. the hr was observed only in the pi-0 ecotype infect ... | 2007 | 17293566 |
| a novel role for the tir domain in association with pathogen-derived elicitors. | plant innate immunity is mediated by resistance (r) proteins, which bear a striking resemblance to animal molecules of similar function. tobacco n is a tir-nb-lrr r gene that confers resistance to tobacco mosaic virus, specifically the p50 helicase domain. an intriguing question is how plant r proteins recognize the presence of pathogen-derived avirulence (avr) elicitor proteins. we have used biochemical cell fraction and immunoprecipitation in addition to confocal fluorescence microscopy of liv ... | 2007 | 17298188 |
| [isolation and ardra analysis of cucumber entophytic antagonists against ralstonia solanacearum]. | cucumber bacteria wilt, caused by ralstonia solanacearum, is one of soilborne plant diseases of worldwide origin. biological control is considered the most environment-safe and efficacious approaches to control this disease. in this study, a total of 469 entophytic bacteria were isolated from cucumber plant roots at different growth stages and 59 of these isolates were shown antagonistic against ralstonia solanacearum. an analysis of the level of biodiversity of the isolates at the species level ... | 2006 | 17302166 |
| isolation and characterisation of ralstonia solanacearum strains from solanaceae crops in ethiopia. | eighty one isolates of ralstonia solanacearum -like bacteria on triphenyl tetrazolium chloride (ttc) medium were collected from different solanaceae crops (i.e. potato, tomato and pepper plants and potato tubers) at various sites in ethiopia. of these, 62 strains were identified as r. solanacearum based on their cultural characteristics on ttc medium, tomato pathogenicity bioassay, carbon source utilisation patterns and a specific pcr-based assay. by hayward's classification method, based on car ... | 2007 | 17304617 |
| plant carbohydrate scavenging through tonb-dependent receptors: a feature shared by phytopathogenic and aquatic bacteria. | tonb-dependent receptors (tbdrs) are outer membrane proteins mainly known for the active transport of iron siderophore complexes in gram-negative bacteria. analysis of the genome of the phytopathogenic bacterium xanthomonas campestris pv. campestris (xcc), predicts 72 tbdrs. such an overrepresentation is common in xanthomonas species but is limited to only a small number of bacteria. here, we show that one xcc tbdr transports sucrose with a very high affinity, suggesting that it might be a sucro ... | 2007 | 17311090 |
| characterization of the interaction between the bacterial wilt pathogen ralstonia solanacearum and the model legume plant medicago truncatula. | the soilborne pathogen ralstonia solanacearum is the causal agent of bacterial wilt and attacks more than 200 plant species, including some legumes and the model legume plant medicago truncatula. we have demonstrated that m. truncatula accessions jemalong a17 and f83005.5 are susceptible to r. solanacearum and, by screening 28 r. solanacearum strains on the two m. truncatula lines, differential interactions were identified. r. solanacearum gmi1000 infected jemalong a17 line, and disease symptoms ... | 2007 | 17313167 |
| x-ray crystallographic analysis of the sulfur carrier protein soxy from chlorobium limicola f. thiosulfatophilum reveals a tetrameric structure. | dissimilatory oxidation of thiosulfate in the green sulfur bacterium chlorobium limicola f. thiosulfatophilum is carried out by the ubiquitous sulfur-oxidizing (sox) multi-enzyme system. in this system, soxy plays a key role, functioning as the sulfur substrate-binding protein that offers its sulfur substrate, which is covalently bound to a conserved c-terminal cysteine, to another oxidizing sox enzyme. here, we report the crystal structures of a stand-alone soxy protein of c. limicola f. thiosu ... | 2007 | 17327392 |
| two host-induced ralstonia solanacearum genes, acra and dinf, encode multidrug efflux pumps and contribute to bacterial wilt virulence. | multidrug efflux pumps (mdrs) are hypothesized to protect pathogenic bacteria from toxic host defense compounds. we created mutations in the ralstonia solanacearum acra and dinf genes, which encode putative mdrs in the broad-host-range plant pathogen. both mutations reduced the ability of r. solanacearum to grow in the presence of various toxic compounds, including antibiotics, phytoalexins, and detergents. both acrab and dinf mutants were significantly less virulent on the tomato plant than the ... | 2007 | 17337552 |
| insertion sequence diversity in archaea. | insertion sequences (iss) can constitute an important component of prokaryotic (bacterial and archaeal) genomes. over 1,500 individual iss are included at present in the isfinder database (www-is.biotoul.fr), and these represent only a small portion of those in the available prokaryotic genome sequences and those that are being discovered in ongoing sequencing projects. in spite of this diversity, the transposition mechanisms of only a few of these ubiquitous mobile genetic elements are known, a ... | 2007 | 17347521 |
| impairment of cellulose synthases required for arabidopsis secondary cell wall formation enhances disease resistance. | cellulose is synthesized by cellulose synthases (cesas) contained in plasma membrane-localized complexes. in arabidopsis thaliana, three types of cesa subunits (cesa4/irregular xylem5 [irx5], cesa7/irx3, and cesa8/irx1) are required for secondary cell wall formation. we report that mutations in these proteins conferred enhanced resistance to the soil-borne bacterium ralstonia solanacearum and the necrotrophic fungus plectosphaerella cucumerina. by contrast, susceptibility to these pathogens was ... | 2007 | 17351116 |
| crystal structures of the pilus retraction motor pilt suggest large domain movements and subunit cooperation drive motility. | pilt is a hexameric atpase required for bacterial type iv pilus retraction and surface motility. crystal structures of adp- and atp-bound aquifex aeolicus pilt at 2.8 and 3.2 a resolution show n-terminal pas-like and c-terminal reca-like atpase domains followed by a set of short c-terminal helices. the hexamer is formed by extensive polar subunit interactions between the atpase core of one monomer and the n-terminal domain of the next. an additional structure captures a nonsymmetric pilt hexamer ... | 2007 | 17355871 |
| burkholderia hep_hag autotransporter (buha) proteins elicit a strong antibody response during experimental glanders but not human melioidosis. | the bacterial biothreat agents burkholderia mallei and burkholderia pseudomallei are the cause of glanders and melioidosis, respectively. genomic and epidemiological studies have shown that b. mallei is a recently emerged, host restricted clone of b. pseudomallei. | 2007 | 17362501 |
| final report on the safety assessment of capsicum annuum extract, capsicum annuum fruit extract, capsicum annuum resin, capsicum annuum fruit powder, capsicum frutescens fruit, capsicum frutescens fruit extract, capsicum frutescens resin, and capsaicin. | capsicum-derived ingredients function as skin-conditioning agents--miscellaneous, external analgesics, flavoring agents, or fragrance components in cosmetics. these ingredients are used in 19 cosmetic products at concentrations as high as 5%. cosmetic-grade material may be extracted using hexane, ethanol, or vegetable oil and contain the full range of phytocompounds that are found in the capsicum annuum or capsicum frutescens plant (aka red chiles), including capsaicin. aflatoxin and n-nitroso c ... | 2007 | 17365137 |
| a symbiotic plant peroxidase involved in bacterial invasion of the tropical legume sesbania rostrata. | aquatic nodulation on the tropical legume sesbania rostrata occurs at lateral root bases via intercellular crack-entry invasion. a gene was identified (srprx1) that is transiently up-regulated during the nodulation process and codes for a functional class iii plant peroxidase. the expression strictly depended on bacterial nodulation factors (nfs) and could be modulated by hydrogen peroxide, a downstream signal for crack-entry invasion. expression was not induced after wounding or pathogen attack ... | 2007 | 17384158 |
| transcriptional regulatory network discovery via multiple method integration: application to e. coli k12. | transcriptional regulatory network (trn) discovery from one method (e.g. microarray analysis, gene ontology, phylogenic similarity) does not seem feasible due to lack of sufficient information, resulting in the construction of spurious or incomplete trns. we develop a methodology, trnd, that integrates a preliminary trn, microarray data, gene ontology and phylogenic similarity to accurately discover trns and apply the method to e. coli k12. the approach can easily be extended to include other me ... | 2007 | 17397539 |
| evaluation of somatic hybrids of potato with solanum stenotomum after a long-term in vitro conservation. | somatic hybrids of potato with a cultivated relative, solanum stenotomum also called solanum tuberosum stenotomum group, were evaluated for their physiological and agronomical characteristics as well as the stability of the introgressed resistance to bacterial wilt, caused by ralstonia solanacearum, after a long-term in vitro conservation for more than 5 years. analysis of photosynthesis showed that the pepc/rubisco ratio remained lower than 0.5 for all vitroplants of potato and the somatic hybr ... | 2007 | 17400465 |
| [high speed separation and quantitation of ralstonia solanacearum of different virulence using high performance ion exchange chromatography]. | high performance ion exchange chromatography coupled with laser light scattering instrument was employed for the rapid separation and quantitation of ralstonia solanacearum of different virulence. the pure culture of ralstonia solanacearum was successfully separated into three characteristic fractions. each fraction was collected and inoculated onto 2,3,5-triphenyltetrazolium chloride (ttc) plates to identify its virulence. the shapes and colors of the colonies were imaged, and the average atten ... | 2007 | 17432579 |
| signal mimics derived from a metagenomic analysis of the gypsy moth gut microbiota. | bacterial signaling is an important part of community life, but little is known about the signal transduction pathways of the as-yet-uncultured members of microbial communities. to address this gap, we aimed to identify genes directing the synthesis of signals in uncultured bacteria associated with the midguts of gypsy moth larvae. we constructed a metagenomic library consisting of dna extracted directly from the midgut microbiota and analyzed it using an intracellular screen designated metrex, ... | 2007 | 17435000 |
| [characterization of ralstonia solanacearum in different growth phases by high performance ion exchange liquid chromatography analysis]. | high performance ion exchange liquid chromatography and laser light scattering instrument were employed to characterize ralstonia solanacearum in different growth phases. the pure culture of ralstonia solanacearum was successfully separated into three characteristic fractions. chromatographic behaviors of ralstonia solanacearum in lag phase, logarithmic phase and stationary phase were carefully investigated, and their relationships to the cell concentration, ph of fermentation broth and extracel ... | 2007 | 17436642 |
| staphylococcal biofilm exopolysaccharide protects against caenorhabditis elegans immune defenses. | staphylococcus epidermidis and staphylococcus aureus are leading causes of hospital-acquired infections that have become increasingly difficult to treat due to the prevalence of antibiotic resistance in these organisms. the ability of staphylococci to produce biofilm is an important virulence mechanism that allows bacteria both to adhere to living and artificial surfaces and to resist host immune factors and antibiotics. here, we show that the icaadbc locus, which synthesizes the biofilm-associa ... | 2007 | 17447841 |
| repeat domain diversity of avrbs3-like genes in ralstonia solanacearum strains and association with host preferences in the field. | genes homologous to avrbs3 of xanthomonas were detected in 309 strains of ralstonia solanacearum biovars 3, 4, and 5 but not biovar 1 or 2. a statistically significant association between the originating plant species and internal repeats of the gene was found. sequences of repeats and variation between nearly clonal strains revealed evidence of frequent recombination. | 2007 | 17468277 |
| using the ralstonia solanacearum tat secretome to identify bacterial wilt virulence factors. | to identify secreted virulence factors involved in bacterial wilt disease caused by the phytopathogen ralstonia solanacearum, we mutated tatc, a key component of the twin-arginine translocation (tat) secretion system. the r. solanacearum tatc mutation was pleiotropic; its phenotypes included defects in cell division, nitrate utilization, polygalacturonase activity, membrane stability, and growth in plant tissue. bioinformatic analysis of the r. solanacearum strain gmi1000 genome predicted that t ... | 2007 | 17468289 |
| combinatorial regulation of genes essential for myxococcus xanthus development involves a response regulator and a lysr-type regulator. | myxococcus xanthus is a bacterium that undergoes multicellular development. c-signaling influences gene expression and movement of cells into aggregates. expression of the dev operon, which includes genes essential for efficient sporulation, depends in part on c-signaling and reaches its highest level in cells within aggregates, ensuring that spores form within fruiting bodies. here, an upstream dna element was found to be essential for dev promoter activity and was bound by frua, a response reg ... | 2007 | 17470804 |
| genomics of glycopeptidolipid biosynthesis in mycobacterium abscessus and m. chelonae. | the outermost layer of the bacterial surface is of crucial importance because it is in constant interaction with the host. glycopeptidolipids (gpls) are major surface glycolipids present on various mycobacterial species. in the fast-grower model organism mycobacterium smegmatis, gpl biosynthesis involves approximately 30 genes all mapping to a single region of 65 kb. | 2007 | 17490474 |
| yscu recognizes translocators as export substrates of the yersinia injectisome. | yscu is an essential component of the export apparatus of the yersinia injectisome. it consists of an n-terminal transmembrane domain and a long cytoplasmic c-terminal domain, which undergoes auto-cleavage at a npth site. substitutions n263a and p264a prevented cleavage of yscu and abolished export of lcrv, yopb and yopd but not of yop effectors. as a consequence, yscu(n263a) mutant bacteria made needles without the lcrv tip complex and they could not form translocation pores. the graft of the e ... | 2007 | 17510628 |
| physiological and molecular responses of lactuca sativa to colonization by salmonella enterica serovar dublin. | this paper describes the physiological and molecular interactions between the human-pathogenic organism salmonella enterica serovar dublin and the commercially available mini roman lettuce cv. tamburo. the association of s. enterica serovar dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. the latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and ... | 2007 | 17513585 |
| nucleotide sequence of plasmid pcnb1 from comamonas strain cnb-1 reveals novel genetic organization and evolution for 4-chloronitrobenzene degradation. | the nucleotide sequence of a new plasmid pcnb1 from comamonas sp. strain cnb-1 that degrades 4-chloronitrobenzene (4cnb) was determined. pcnb1 belongs to the incp-1beta group and is 91,181 bp in length. a total of 95 open reading frames appear to be involved in (i) the replication, maintenance, and transfer of pcnb1; (ii) resistance to arsenate and chromate; and (iii) the degradation of 4cnb. the 4cnb degradative genes and arsenate resistance genes were located on an extraordinarily large transp ... | 2007 | 17526790 |