Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| plant-microbe interactions: identification of epiphytic bacteria and their ability to alter leaf surface permeability. | bacteria were either isolated from leaf surfaces of hedera helix or obtained from a culture collection in order to analyse their effect on barrier properties of isolated hedera and prunus laurocerasus cuticles. on the basis of the 16s rdna sequences the genera of the six bacterial isolates from hedera were identified as pseudomonas sp., stenotrophomonas sp. and achromobacter. water permeability of cuticles isolated from h. helix was measured before and after inoculation with the six bacterial st ... | 2005 | 15819920 |
| deduction of probable events of lateral gene transfer through comparison of phylogenetic trees by recursive consolidation and rearrangement. | when organismal phylogenies based on sequences of single marker genes are poorly resolved, a logical approach is to add more markers, on the assumption that weak but congruent phylogenetic signal will be reinforced in such multigene trees. such approaches are valid only when the several markers indeed have identical phylogenies, an issue which many multigene methods (such as the use of concatenated gene sequences or the assembly of supertrees) do not directly address. indeed, even when the true ... | 2005 | 15819979 |
| molecular properties of the xanthomonas avrrxv effector and global transcriptional changes determined by its expression in resistant tomato plants. | the xanthomonas campestris pv. vesicatoria avirulence gene avrrxv specifies resistance on the tomato line hawaii 7998 by interacting with three nondominant plant resistance genes. avrrxv molecular properties that impinge on its avirulence activity were characterized and transcriptional changes caused by avrrxv expression in resistant tomato plants were extensively examined. avrrxv localized predominantly to the cytoplasm and possibly in association with plasma and nuclear membranes in both resis ... | 2005 | 15828682 |
| identification of a new quorum-sensing-controlled virulence factor in erwinia carotovora subsp. atroseptica secreted via the type ii targeting pathway. | two-dimensional polyacrylamide gel electrophoresis of the secreted proteins of erwinia carotovora subsp. atroseptica revealed a low-abundance protein that was identified by mass spectrometry as a homologue of a xanthomonas campestris avirulence protein with unknown function. the predicted svx protein has an n-terminal signal sequence and zinc binding-region signature, and the mature protein is post-translationally modified. a 2d difference gel electrophoresis (dige) showed that the protein is se ... | 2005 | 15828685 |
| three prochlorococcus cyanophage genomes: signature features and ecological interpretations. | the oceanic cyanobacteria prochlorococcus are globally important, ecologically diverse primary producers. it is thought that their viruses (phages) mediate population sizes and affect the evolutionary trajectories of their hosts. here we present an analysis of genomes from three prochlorococcus phages: a podovirus and two myoviruses. the morphology, overall genome features, and gene content of these phages suggest that they are quite similar to t7-like (p-ssp7) and t4-like (p-ssm2 and p-ssm4) ph ... | 2005 | 15828858 |
| novel roles of ohrr-ohr in xanthomonas sensing, metabolism, and physiological adaptive response to lipid hydroperoxide. | lipid hydroperoxides are highly toxic to biological systems. here, the xanthomonas campestris pv. phaseoli sensing and protective systems against linoleic hydroperoxide (looh) were investigated by examining the phenotypes, biochemical and regulatory characteristics of various xanthomonas mutants in known peroxide resistance pathways. analysis of looh resistance levels indicates that both alkyl hydroperoxide reductase (ahpc) and organic hydroperoxide resistance enzyme (ohr) have important and non ... | 2005 | 15838057 |
| spoilage of vegetable crops by bacteria and fungi and related health hazards. | after harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. the most common bacterial agents are erwinia carotovora, pseudomonas spp., corynebacterium, xanthomonas campestris, and lactic acid bacteria with e. carotovora being the most common, attacking virtually every vegetable type. fungi commonly causing spoilage of fresh vegetables are botrytis cinerea, various species of the genera alternaria, aspergillus, cladosporium, colleto ... | 2005 | 15839403 |
| synthesis and characterization of novel 6-fluoro-4-piperidinyl-1,2-benzisoxazole amides and 6-fluoro-chroman-2-carboxamides: antimicrobial studies. | novel derivatives of 6-fluoro-4-piperidinyl-1,2-benzisoxazole amides 4(i-vi) were obtained by the condensation of different acid chlorides with 6-fluoro-3-piperidin-4yl-benzo[d]isoxazole. also, 6-fluoro-chroman-2-carboxamides 6(i-iii) were synthesized by using nebulic acid chloride with different amines in presence of triethylamine as acid scavenger and dichloroethane as solvent. the synthesized compounds were characterized by ir, 1h nmr, and chn analysis. these molecules were evaluated for thei ... | 2005 | 15846867 |
| antisense suppression of a (+)-delta-cadinene synthase gene in cotton prevents the induction of this defense response gene during bacterial blight infection but not its constitutive expression. | in cotton (gossypium hirsutum) the enzyme (+)-delta-cadinene synthase (cdns) catalyzes the first committed step in the biosynthesis of cadinane-type sesquiterpenes, such as gossypol, that provide constitutive and inducible protection against pests and diseases. a cotton cdna clone encoding cdns (cdn1-c4) was isolated from developing embryos and functionally characterized. southern analysis showed that cdns genes belong to a large multigene family, of which five genomic clones were studied, inclu ... | 2005 | 15849309 |
| characterization of a recombinant type ii 3-deoxy-d-arabino-heptulosonate-7-phosphate synthase from helicobacter pylori. | dah7p (3-deoxy-d-arabino-heptulosonate 7-phosphate) synthase catalyses the condensation reaction between phosphoenolpyruvate (pep) and d-erythrose 4-phosphate (e4p) as the first committed step in the biosynthesis of aromatic compounds in plants and micro-organisms. previous work has identified two families of dah7p synthases based on sequence similarity and molecular mass, with the majority of the mechanistic and structural studies being carried out on the type i paralogues from escherichia coli ... | 2005 | 15853768 |
| biofilm formation and sloughing in serratia marcescens are controlled by quorum sensing and nutrient cues. | we describe here a role for quorum sensing in the detachment, or sloughing, of serratia marcescens filamentous biofilms, and we show that nutrient conditions affect the biofilm morphotype. under reduced carbon or nitrogen conditions, s. marcescens formed a classical biofilm consisting of microcolonies. the filamentous biofilm could be converted to a microcolony-type biofilm by switching the medium after establishment of the biofilm. similarly, when initially grown as a microcolony biofilm, s. ma ... | 2005 | 15866935 |
| bacillus subtilis 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase revisited: resolution of two long-standing enigmas. | the mono/bifunctional and metallo/non-metallo properties of bacillus subtilis dahps (3-deoxy-d-arabino-heptulosonate 7-phosphate synthase) have been controversial for several decades. the present study investigated the dahpss from both the b. subtilis parent marburg strain and the derivative strain 168 in detail and clarified the above two long-standing questions. the dahpss from the parent and the derivative 168 strains have identical sequence and are both bifunctional enzymes with a cm (choris ... | 2005 | 15869469 |
| reduced genetic variation occurs among genes of the highly clonal plant pathogen xanthomonas axonopodis pv. vesicatoria, including the effector gene avrbs2. | the bacterial plant pathogen xanthomonas axonopodis pv. vesicatoria, also known as xanthomonas campestris pv. vesicatoria group a, is the causal agent of bacterial spot in pepper and tomato. in order to test different models that may explain the coevolution of avrbs2 with its host plants, we sequenced avrbs2 and six chromosomal loci (total of 5.5 kb per strain) from a global sample of 55 x. axonopodis pv. vesicatoria strains collected from diseased peppers. we found an extreme lack of genetic va ... | 2005 | 15870329 |
| the unique glutathione reductase from xanthomonas campestris: gene expression and enzyme characterization. | the glutathione reductase gene, gor, was cloned from the plant pathogen xanthomonas campestris pv. phaseoli. its gene expression and enzyme characteristics were found to be different from those of previously studied homologues. northern blot hybridization, promoter-lacz fusion, and enzyme assay experiments revealed that its expression, unlike in escherichia coli, is oxyr-independent and constitutive upon oxidative stress conditions. the deduced amino acid sequence shows a unique nadph binding mo ... | 2005 | 15883020 |
| genomic and proteomic comparisons between bacterial and archaeal genomes and related comparisons with the yeast and fly genomes. | bacterial, archaeal, yeast, and fly genomes are compared with respect to predicted highly expressed (phx) genes and several genomic properties. there is a striking difference in the status of phx ribosomal protein (rp) genes where the archaeal genome generally encodes more rp genes and fewer phx rps compared with bacterial genomes. the increase in rps in archaea and eukaryotes compared with that in bacteria may reflect a more complex set of interactions in archaea and eukaryotes in regulating tr ... | 2005 | 15883367 |
| an sos-regulated operon involved in damage-inducible mutagenesis in caulobacter crescentus. | dna polymerases of the y-family, such as escherichia coli umuc and dinb, are specialized enzymes induced by the sos response, which bypass lesions allowing the continuation of dna replication. umudc orthologs are absent in caulobacter crescentus and other bacteria, raising the question about the existence of sos mutagenesis in these organisms. here, we report that the c.crescentus dinb ortholog is not involved in damage-induced mutagenesis. however, an operon composed of two hypothetical genes a ... | 2005 | 15886391 |
| the tyra family of aromatic-pathway dehydrogenases in phylogenetic context. | the tyra protein family includes members that catalyze two dehydrogenase reactions in distinct pathways leading to l-tyrosine and a third reaction that is not part of tyrosine biosynthesis. family members share a catalytic core region of about 30 kda, where inhibitors operate competitively by acting as substrate mimics. this protein family typifies many that are challenging for bioinformatic analysis because of relatively modest sequence conservation and small size. | 2005 | 15888209 |
| bacteriophage control of foodborne bacteriat. | bacteriophages are measurable components of the natural microflora in the food production continuum from the farm to the retail outlet. phages are remarkably stable in these environments and are readily recovered from soil, sewage, water, farm and processing plant effluents, feces, and retail foods. purified high-titer phage lysates have been used for the species-specific control of bacteria during the pre- and postharvest phases of food production and storage. for example, the inhibition of the ... | 2005 | 15895751 |
| comparative and functional genomic analyses of the pathogenicity of phytopathogen xanthomonas campestris pv. campestris. | xanthomonas campestris pathovar campestris (xcc) is the causative agent of crucifer black rot disease, which causes severe losses in agricultural yield world-wide. this bacterium is a model organism for studying plant-bacteria interactions. we sequenced the complete genome of xcc 8004 (5,148,708 bp), which is highly conserved relative to that of xcc atcc 33913. comparative genomics analysis indicated that, in addition to a significant genomic-scale rearrangement cross the replication axis betwee ... | 2005 | 15899963 |
| prediction of functional modules based on comparative genome analysis and gene ontology application. | we present a computational method for the prediction of functional modules encoded in microbial genomes. in this work, we have also developed a formal measure to quantify the degree of consistency between the predicted and the known modules, and have carried out statistical significance analysis of consistency measures. we first evaluate the functional relationship between two genes from three different perspectives--phylogenetic profile analysis, gene neighborhood analysis and gene ontology ass ... | 2005 | 15901854 |
| gene expression analysis of six gc-rich gram-negative phytopathogens. | predicted highly expressed (phx) genes are comparatively analyzed for six gc-rich gram-negative phytopathogens, i.e., ralstonia solanacearum, agrobacterium tumefaciens, xanthomonas campestris pv. campestris (xcc), xanthomonas axonopodis pv. citri (xac), pseudomonas syringae pv. tomato, and xylella fastidiosa. enzymes involved in energy metabolism, such as atp synthase, and genes involved in tca cycle, are phx in most bacteria except x. fastidiosa, which prefers an anaerobic environment. most pat ... | 2005 | 15910748 |
| functional analysis of the early chlorosis factor gene. | chlorosis is one of the symptoms of bacterial spot disease caused by xanthomonas campestris pv. vesicatoria, which induces chlorosis before any other symptoms appear on tomato. we report characterization of a 2.1-kb gene called early chlorosis factor (ecf). the gene ecf encodes a hydrophobic protein with similarity to four other proteins in plant pathogens, including holpsyae, and uncharacterized gene products from x. campestris pv. campestris and x. axonopodis pv. citri, and, at the tertiary st ... | 2005 | 15915646 |
| the arabidopsis plastidic methionine sulfoxide reductase b proteins. sequence and activity characteristics, comparison of the expression with plastidic methionine sulfoxide reductase a, and induction by photooxidative stress. | two types of methionine (met) sulfoxide reductases (msr) catalyze the reduction of met sulfoxide (metso) back to met. msra, well characterized in plants, exhibits an activity restricted to the met-s-so-enantiomer. recently, a new type of msr enzyme, called msrb, has been identified in various organisms and shown to catalytically reduce the r-enantiomer of metso. in plants, very little information is available about msrb and we focused our attention on arabidopsis (arabidopsis thaliana) msrb prot ... | 2005 | 15923321 |
| automatic selection of representative proteins for bacterial phylogeny. | although there are now about 200 complete bacterial genomes in genbank, deep bacterial phylogeny remains a difficult problem, due to confounding horizontal gene transfers and other phylogenetic "noise". previous methods have relied primarily upon biological intuition or manual curation for choosing genomic sequences unlikely to be horizontally transferred, and have given inconsistent phylogenies with poor bootstrap confidence. | 2005 | 15927057 |
| emergent mechanistic diversity of enzyme-catalysed beta-diketone cleavage. | the enzymatic cleavage of c-c bonds in beta-diketones is, comparatively, a little studied biochemical process, but one that has important relevance to human metabolism, bioremediation and preparative biocatalysis. in recent studies, four types of enzymes have come to light that cleave c-c bonds in the beta-diketone functionality using different chemical mechanisms. oph [oxidized poly(vinyl alcohol) hydrolase from pseudomonas sp. strain vm15c], which cleaves nonane-4,6-dione to butyrate and penta ... | 2005 | 15934927 |
| pseudomonas syringae type iii chaperones shco1, shcs1, and shcs2 facilitate translocation of their cognate effectors and can substitute for each other in the secretion of hopo1-1. | the pseudomonas syringae type iii secretion system (ttss) translocates effector proteins into plant cells. several p. syringae effectors require accessory proteins called type iii chaperones (ttcs) to be secreted via the ttss. we characterized the hopo1-1, hops1, and hops2 operons in p. syringae pv. tomato dc3000; these operons encode three homologous ttcs, shco1, shcs1, and shcs2. shco1, shcs1, and shcs2 facilitated the type iii secretion and/or translocation of their cognate effectors hopo1-1, ... | 2005 | 15937188 |
| systemic acquired tolerance to virulent bacterial pathogens in tomato. | recent studies on the interactions between plants and pathogenic microorganisms indicate that the processes of disease symptom development and pathogen growth can be uncoupled. thus, in many instances, the symptoms associated with disease represent an active host response to the presence of a pathogen. these host responses are frequently mediated by phytohormones. for example, ethylene and salicylic acid (sa) mediate symptom development but do not influence bacterial growth in the interaction be ... | 2005 | 15937273 |
| unraveling the secret lives of bacteria: use of in vivo expression technology and differential fluorescence induction promoter traps as tools for exploring niche-specific gene expression. | a major challenge for microbiologists is to elucidate the strategies deployed by microorganisms to adapt to and thrive in highly complex and dynamic environments. in vitro studies, including those monitoring genomewide changes, have proven their value, but they can, at best, mimic only a subset of the ensemble of abiotic and biotic stimuli that microorganisms experience in their natural habitats. the widely used gene-to-phenotype approach involves the identification of altered niche-related phen ... | 2005 | 15944455 |
| the tetr family of transcriptional repressors. | we have developed a general profile for the proteins of the tetr family of repressors. the stretch that best defines the profile of this family is made up of 47 amino acid residues that correspond to the helix-turn-helix dna binding motif and adjacent regions in the three-dimensional structures of tetr, qacr, cprb, and ethr, four family members for which the function and three-dimensional structure are known. we have detected a set of 2,353 nonredundant proteins belonging to this family by scree ... | 2005 | 15944459 |
| protein length in eukaryotic and prokaryotic proteomes. | we analyzed length differences of eukaryotic, bacterial and archaeal proteins in relation to function, conservation and environmental factors. comparing eukaryotes and prokaryotes, we found that the greater length of eukaryotic proteins is pervasive over all functional categories and involves the vast majority of protein families. the magnitude of these differences suggests that the evolution of eukaryotic proteins was influenced by processes of fusion of single-function proteins into extended m ... | 2005 | 15951512 |
| clp upregulates transcription of enga gene encoding a virulence factor in xanthomonas campestris by direct binding to the upstream tandem clp sites. | in xanthomonas campestris, the causative agent of black rot in crucifers, the endoglucanase level is greatly decreased in the mutant deficient in clp, a homologue of cyclic amp receptor protein (crp). it is established that clp has the same dna binding specificity as crp at positions 5, 6, and 7 (gtg motif) of the dna half site. in this study, the enga transcription initiation site was determined by the 5' race method, and two consensus clp-binding sites, site i and site ii centered at -69.5 and ... | 2005 | 15955530 |
| [the gene wxca of xanthomonas campestris pv. campestris 8004 strain involved in eps yield]. | xanthomonas campestris pv. campestris (xcc), the pathogenic agent of black rot disease in cruciferous plants, produces large amount of extracellular polysaccharide (eps), which has found wide applications in industry. for the great commercial value of the xanthan gum, many of the genes involved in eps biosynthesis have been cloned and the mechanism of eps biosynthesis also has been studied. in order to clone genes involved in eps biosynthesis, xcc wild-type strain 8004 was mutagenized with trans ... | 2004 | 15968974 |
| non-gamma-proteobacteria gene islands contribute to the xanthomonas genome. | horizontal gene transfer, a process through which genomes acquire sequences from distantly related organisms, is believed to be a major source of genetic diversity in bacteria. a central question concerning the impact of gene transfer on bacterial genome evolution is the proportion of horizontally transferred sequences within genomes. through blast search, we found that the genomes of two phytopathogens, xanthomonas campestris pv. campestris and xanthomonas axonopodis pv. citri, have close to 40 ... | 2005 | 15969648 |
| [identification and cloning of a novel gene involved in eps biosynthesis of xanthomonas campestris pv. campestris]. | xanthomonas campestris pv. campestris ( xcc), causative agent of the black rot disease of cruciferous crops worldwide, produces large amount of extracellular polysaccharide( eps), which has found wide applications in industry. in order to clone genes involved in eps biosynthesis, xcc wild-type strain 8004 was mutagenized with transposon tn5gus a5, and a number of eps-defective mutants were isolated. the tn5gusa5 insertion sites in the mutants were analyzed by using thermal asymmetric interlaced ... | 2003 | 15971576 |
| novel approach to mapping of resistance mutations in whole genomes by using restriction enzyme modulation of transformation efficiency. | restriction enzyme modulation of transformation efficiencies (remote) is a method that makes use of genome restriction maps and experimentally observed differences in transformation efficiencies of genomic dna restriction digests to discover the location of mutations in genomes. the frequency with which digested genomic dna from a resistant strain transforms a susceptible strain to resistance is primarily determined by the size of the fragment containing the resistance mutation and the distance ... | 2005 | 15980348 |
| identification of plant-induced genes of the bacterial pathogen xanthomonas campestris pathovar campestris using a promoter-probe plasmid. | a promoter-probe plasmid suitable for use in xanthomonas campestris pathovar campestris (causal agent of crucifer black rot) was constructed by ligating a broad host range incq replicon into the promoter-probe plasmid pkk232-8, which contains a promoterless chloramphenicol acetyltransferase gene. xanthomonas chromosomal dna fragments were 'shotgun' cloned into a restriction site in front of this gene, and the resulting library was transferred en masse into xanthomonas. individual transconjugants ... | 1987 | 15981331 |
| the map kinase substrate mks1 is a regulator of plant defense responses. | arabidopsis map kinase 4 (mpk4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (sa)-dependent resistance and for activation of jasmonate (ja)-dependent defense gene expression. to understand mpk4 signaling mechanisms, we used yeast two-hybrid screening to identify the mpk4 substrate mks1. analyses of transgenic plants and genome-wide transcript profiling indicated that mks1 is required for full sa-dependent resistance in mpk4 ... | 2005 | 15990873 |
| oxyr mediated compensatory expression between ahpc and kata and the significance of ahpc in protection from hydrogen peroxide in xanthomonas campestris. | kata and ahpc, encoding monofunctional catalase and alkyl hydroperoxide reductase, respectively, play important protective roles against peroxide toxicity in xanthomonas campestris pv. phaseoli (xp). the expression of both kata and ahpc is controlled by the global peroxide sensor and transcriptional activator, oxyr. in xp, these two genes have compensatory expression patterns. inactivation of kata leads to an increase in the level of ahpc and a concomitant increase in resistance to tert-butyl hy ... | 2005 | 15993009 |
| specific control of endogenous ccf10 pheromone by a conserved domain of the pcf10-encoded regulatory protein prgy in enterococcus faecalis. | conjugative transfer of enterococcus faecalis plasmid pcf10 is induced by the heptapeptide pheromone ccf10. ccf10 produced by plasmid-free recipient cells is detected by pcf10-containing donor cells, which respond by induction of plasmid-encoded transfer functions. the pcf10-encoded membrane protein prgy is essential to prevent donor cells from responding to endogenously produced pheromone while maintaining the ability to respond to pheromone from an exogenous source; this function has not been ... | 2005 | 15995198 |
| functional and topological analysis of the burkholderia cenocepacia priming glucosyltransferase bceb, involved in the biosynthesis of the cepacian exopolysaccharide. | the bceb protein of the cystic fibrosis mucoid isolate burkholderia cenocepacia ist432 is proposed to catalyze the first step of the exopolysaccharide repeat unit assembly. extracts of escherichia coli cells overexpressing bceb were shown to contain glycosyltransferase activity and mediate incorporation of glucose-1-phosphate into membrane lipids. the amino acid sequence of bceb exhibits two conserved regions, one comprising two invariant aspartic acid residues (asp339 and asp355) that are essen ... | 2005 | 15995219 |
| potential application of ribosomal intergenic spacer analysis to the microbial community analysis of agronomic products. | ribosomal intergenic spacer analysis (risa) has been applied to the microbial community analysis of agronomic products in combination with a simple and rapid dna extraction method, consisting of a one-step extraction and two-step purification, for a variety of agronomic products. risa appears to be a useful tool for the study of the community structures of food-associated microbes and their use as a unique fingerprinting signature for each agronomic product. sequencing analyses of amplicons gene ... | 2005 | 15998122 |
| relative importance of bacteriocin-like genes in antagonism of xanthomonas perforans tomato race 3 to xanthomonas euvesicatoria tomato race 1 strains. | in a previous study, tomato race 3 (t3) strains of xanthomonas perforans became predominant in fields containing both x. euvesicatoria and x. perforans races t1 and t3, respectively. this apparent ability to take over fields led to the discovery that there are three bacteriocin-like compounds associated with t3 strains. t3 strain 91-118 produces at least three different bacteriocin-like compounds (bcn-a, bcn-b, and bcn-c) antagonistic toward t1 strains. we determined the relative importance of t ... | 2005 | 16000765 |
| changes in race-specific virulence in pseudomonas syringae pv. phaseolicola are associated with a chimeric transposable element and rare deletion events in a plasmid-borne pathogenicity island. | virulence for bean and soybean is determined by effector genes in a plasmid-borne pathogenicity island (pai) in race 7 strain 1449b of pseudomonas syringae pv. phaseolicola. one of the effector genes, avrpphf, confers either pathogenicity, virulence, or avirulence depending on the plant host and is absent from races 2, 3, 4, 6, and 8 of this pathogen. analysis of cosmid clones and comparison of dna sequences showed that the absence of avrpphf from strain 1448a is due to deletion of a continuous ... | 2005 | 16000789 |
| phylogenetic analysis of the phytochrome superfamily reveals distinct microbial subfamilies of photoreceptors. | phys (phytochromes) are a superfamily of photochromic photoreceptors that employ a bilin-type chromophore to sense red and far-red light. although originally thought to be restricted to plants, accumulating genetic and genomic analyses now indicate that they are also prevalent among micro-organisms. by a combination of phylogenetic and biochemical studies, we have expanded the phy superfamily and organized its members into distinct functional clades which include the phys (plant phys), bphps (ba ... | 2005 | 16004604 |
| effect of the lactoperoxidase system against three major causal agents of disease in mangoes. | the antibacterial activity of the lactoperoxidase system (lps) on the growth of xanthomonas campestris, the causal agent of bacterial black spot in mangoes, botryodiplodia theobromae, the causal agent of stem-end rot disease in mangoes, and colletotrichum gloeosporioides, the causal agent of anthracnose disease in mangoes, was determined during culture at 30 degrees c and at several ph values (4.5, 5.5, and 6.5). when the results of using the lps were compared with those from control cultures wi ... | 2005 | 16013395 |
| origin and evolution of the archaeo-eukaryotic primase superfamily and related palm-domain proteins: structural insights and new members. | we report an in-depth computational study of the protein sequences and structures of the superfamily of archaeo-eukaryotic primases (aeps). this analysis greatly expands the range of diversity of the aeps and reveals the unique active site shared by all members of this superfamily. in particular, it is shown that eukaryotic nucleo-cytoplasmic large dna viruses, including poxviruses, asfarviruses, iridoviruses, phycodnaviruses and the mimivirus, encode aeps of a distinct family, which also includ ... | 2005 | 16027112 |
| use of suppression-subtractive hybridization to identify genes in the burkholderia cepacia complex that are unique to burkholderia cenocepacia. | we have previously shown differences in virulence between species of the burkholderia cepacia complex using the alfalfa infection model and the rat agar bead chronic infection model. burkholderia cenocepacia strains were more virulent in these two infection models than burkholderia multivorans and burkholderia stabilis strains. in order to identify genes that may account for the increased virulence of b. cenocepacia, suppression-subtractive hybridization was performed between b. cenocepacia k56- ... | 2005 | 16030222 |
| a computational approach for identifying pathogenicity islands in prokaryotic genomes. | pathogenicity islands (pais), distinct genomic segments of pathogens encoding virulence factors, represent a subgroup of genomic islands (gis) that have been acquired by horizontal gene transfer event. up to now, computational approaches for identifying pais have been focused on the detection of genomic regions which only differ from the rest of the genome in their base composition and codon usage. these approaches often lead to the identification of genomic islands, rather than pais. | 2005 | 16033657 |
| the zinc uptake regulator zur is essential for the full virulence of xanthomonas campestris pv. campestris. | zur is a regulator of the high-affinity zinc uptake system in many bacteria. in xanthomonas campestris pv. campestris 8004, a putative protein encoded by the open reading frame designated as xc1430 shows 42% amino acid similarity with the zur of escherichia coli. an xc1430-disrupted mutant 1430nk was constructed by homologous suicide plasmid integration. 1430nk failed to grow in rich medium supplemented with zn2+ at a concentration of 400 microm and in nonrich medium supplemented with zn2+ at a ... | 2005 | 16042011 |
| characterization of the xanthomonas campestris pv. campestris lipopolysaccharide substructures essential for elicitation of an oxidative burst in tobacco cells. | the lipopolysaccharides (lps) of gram-negative bacteria are essential for perception of pathogens by animals and plants. to identify the lps substructure or substructures recognized by plants, we isolated water-phase (w)lps from different xanthomonas campestris pv. campestris mutants and analyzed their sugar content and ability to elicit an oxidative burst in tobacco cell cultures. the different wlps species are characterized by lacking repetitive subunits of the o-antigen, the complete o-antige ... | 2005 | 16042013 |
| the elicitation of plant innate immunity by lipooligosaccharide of xanthomonas campestris. | lipopolysaccharides (lpss) and lipooligosaccharides (loss) are major components of the cell surface of gram-negative bacteria with diverse roles in bacterial pathogenesis of animals and plants that include elicitation of host defenses. little is known about the mechanisms of perception of these molecules by plants and about the associated signal transduction pathways that trigger plant immunity. here we address the issue of the molecular basis of elicitation of plant defenses through the structu ... | 2005 | 16048996 |
| decoding microbial chatter: cell-cell communication in bacteria. | 2005 | 16077095 | |
| important role for methionine sulfoxide reductase in the oxidative stress response of xanthomonas campestris pv. phaseoli. | a methionine sulfoxide reductase gene (msra) from xanthomonas campestris pv. phaseoli has unique expression patterns and physiological function. msra expression is growth dependent and is highly induced by exposure to oxidants and n-ethylmaleimide in an oxyr- and ohrr-independent manner. an msra mutant showed increased sensitivity to oxidants but only during stationary phase. | 2005 | 16077131 |
| roles of the minor pseudopilins, xpsh, xpsi and xpsj, in the formation of xpsg-containing pseudopilus in xanthomonas campestris pv. campestris. | due to their similarity to type iv pilus (tfp) subunits, the pseudopilins, xpsg, -h, -i, -j and -k, have been predicted to form a pilus-like structure in the type ii secretion (t2s) pathway. while overexpression of gspg can result in the formation of bundle structures, the functions of other pseudopilin are not known yet. in this study, we investigate the mutual interaction among the pseudopilins and characterize the specialized minor pseudopilin, xpsj. by using gel filtration and ni-nta affinit ... | 2005 | 16078004 |
| resistance of cotton towards xanthomonas campestris pv. malvacearum. | interactions between gossypium spp. and the bacterial pathogen xanthomonas campestris pv. malvacearum are understood in the context of the gene-for-gene concept. reviewed here are the genetic basis for cotton resistance, with reference to resistance genes, resistance gene analogs, and bacterial avirulence genes, together with the physiological mechanisms involved in the hypersensitive response to the pathogen, including production of signaling hormones, synthesis of antimicrobial molecules and a ... | 2005 | 16078877 |
| proteins encoded by sphingomonas elodea atcc 31461 rmla and ugpg genes, involved in gellan gum biosynthesis, exhibit both dtdp- and udp-glucose pyrophosphorylase activities. | the commercial gelling agent gellan is a heteropolysaccharide produced by sphingomonas elodea atcc 31461. in this work, we carried out the biochemical characterization of the enzyme encoded by the first gene (rmla) of the rml 4-gene cluster present in the 18-gene cluster required for gellan biosynthesis (gel cluster). based on sequence homology, the putative rml operon is presumably involved in the biosynthesis of dtdp-rhamnose, the sugar necessary for the incorporation of rhamnose in the gellan ... | 2005 | 16085866 |
| structural and dynamic properties of bacterial type iv secretion systems (review). | the type iv secretion systems (t4ss) are widely distributed among the gram-negative and -positive bacteria. these systems mediate the transfer of dna and protein substrates across the cell envelope to bacterial or eukaryotic cells generally through a process requiring direct cell-to-cell contact. bacteria have evolved t4ss for survival during establishment of pathogenic or symbiotic relationships with eukaryotic hosts. the agrobacterium tumefaciens virb/d4 t4ss and related conjugation machines s ... | 2005 | 16092524 |
| reclassification of xanthomonas campestris pv. citri (ex hasse 1915) dye 1978 forms a, b/c/d, and e as x. smithii subsp. citri (ex hasse) sp. nov. nom. rev. comb. nov., x. fuscans subsp. aurantifolii (ex gabriel 1989) sp. nov. nom. rev. comb. nov., and x. alfalfae subsp. citrumelo (ex riker and jones) gabriel et al., 1989 sp. nov. nom. rev. comb. nov.; x. campestris pv malvacearum (ex smith 1901) dye 1978 as x. smithii subsp. smithii nov. comb. nov. nom. nov.; x. campestris pv. alfalfae (ex riker and jones, 1935) dye 1978 as x. alfalfae subsp. alfalfae (ex riker et al., 1935) sp. nov. nom. rev.; and "var. fuscans" of x. campestris pv. phaseoli (ex smith, 1987) dye 1978 as x. fuscans subsp. fuscans sp. nov. | bacterial canker of citrus is a serious disease of citrus worldwide. five forms of the disease have been described, cankers "a", "b", "c", "d", and "e". although considerable genetic diversity has been described among the causal agents of the five forms of citrus canker and supports multiple taxons, the causal agents currently are classified as pathovars citri ("a"), aurantifolii ("b/c/d") and citrumelo ("e") of a single species, xanthomonas campestris pv. citri (or x. axonopodis pv. citri). to ... | 2005 | 16104350 |
| the heat shock genes dnak, dnaj, and grpe are involved in regulation of putisolvin biosynthesis in pseudomonas putida pcl1445. | pseudomonas putida pcl1445 produces two cyclic lipopeptides, putisolvins i and ii, which possess surfactant activity and play an important role in biofilm formation and degradation. in order to identify genes and traits that are involved in the regulation of putisolvin production of pcl1445, a tn5luxab library was generated and mutants were selected for the lack of biosurfactant production using a drop-collapsing assay. sequence analysis of the tn5luxab flanking region of one biosurfactant mutan ... | 2005 | 16109938 |
| domain structure of hrpe, the hrp pilus subunit of xanthomonas campestris pv. vesicatoria. | the plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria possesses a type iii secretion (tts) system necessary for pathogenicity in susceptible hosts and induction of the hypersensitive response in resistant plants. this specialized protein transport system is encoded by a 23-kb hrp (hypersensitive response and pathogenicity) gene cluster. x. campestris pv. vesicatoria produces filamentous structures, hrp pili, at the cell surface under hrp-inducing conditions. the hrp pilus acts as ... | 2005 | 16109959 |
| xanthomonas campestris pv. campestris possesses a single gluconeogenic pathway that is required for virulence. | disruption of ppsa, a key gene in gluconeogenesis, of xanthomonas campestris pv. campestris resulted in the failure of the pathogen to grow in medium with pyruvate or c4-dicarboxylates as the sole carbon source and a significant reduction in virulence, indicating that x. campestris pv. campestris possesses only the malic enzyme-ppsa route in gluconeogenesis, which is required for virulence. | 2005 | 16109965 |
| opsx from haemophilus influenzae represents a novel type of heptosyltransferase i in lipopolysaccharide biosynthesis. | the inner core region of the lipopolysaccharide (lps) of haemophilus influenzae is characterized by the presence of a phosphorylated 3-deoxy-alpha-d-manno-octulosonic acid (kdo). in this study, we show that the heptosyltransferase i adding the first l-glycero-d-manno-heptose residue to this acceptor is encoded by the gene opsx, which differs in substrate specificity from the other heptosyltransferase i, known as waac. | 2005 | 16109967 |
| deduction of upstream sequences of xanthomonas campestris flagellar genes responding to transcription activation by fleq. | xanthomonas campestris pv. campestris (xcc), a close relative to pseudomonas aeruginosa, is the pathogen causing black rot in cruciferous plants. in p. aeruginosa, fleq serves as a cognate activator of sigma54 in transcription from several sigma54-dependent promoters of flagellar genes. these p. aeruginosa promoters have been analyzed for fleq-binding sequences; however, no consensus was deduced. xcc, although lacks flesr, has a fleq homologue residing among over 40 contiguously clustered flagel ... | 2005 | 16111660 |
| gh97 is a new family of glycoside hydrolases, which is related to the alpha-galactosidase superfamily. | as a rule, about 1% of genes in a given genome encode glycoside hydrolases and their homologues. on the basis of sequence similarity they have been grouped into more than ninety gh families during the last 15 years. the gh97 family has been established very recently and initially included only 18 bacterial proteins. however, the evolutionary relationship of the genes encoding proteins of this family remains unclear, as well as their distribution among main groups of the living organisms. | 2005 | 16131397 |
| characterization of avrbs3-like effectors from a brassicaceae pathogen reveals virulence and avirulence activities and a protein with a novel repeat architecture. | xanthomonas campestris pv. armoraciae strain 5 is a brassicaceae pathogen that expresses three members of the highly related avrbs3 gene family of type iii effectors. here, we report on the isolation and characterization of these genes, designated hax2, hax3, and hax4 (homolog of avrbs3 in xanthomonas). all three hax proteins are translocated from xanthomonas spp. into the plant cell via the type iii secretion system. hax3 and hax4 show the typical structure of avrbs3-like effectors and contain ... | 2005 | 16134896 |
| use of plant growth-promoting bacteria for biocontrol of plant diseases: principles, mechanisms of action, and future prospects. | 2005 | 16151072 | |
| new chitosan-degrading strains that produce chitosanases similar to choa of mitsuaria chitosanitabida. | the betaproteobacterium mitsuaria chitosanitabida (formerly matsuebacter chitosanotabidus) 3001 produces a chitosanase (choa) that is classified in glycosyl hydrolase family 80. while many chitosanase genes have been isolated from various bacteria to date, they show limited homology to the m. chitosanitabida 3001 chitosanase gene (choa). to investigate the phylogenetic distribution of chitosanases analogous to choa in nature, we identified 67 chitosan-degrading strains by screening and investiga ... | 2005 | 16151097 |
| novel lectin-like bacteriocins of biocontrol strain pseudomonas fluorescens pf-5. | bacteriocin llpa, produced by pseudomonas sp. strain bw11m1, is a peculiar antibacterial protein due to its homology to mannose-binding lectins mostly found in monocots (a. h. a. parret, g. schoofs, p. proost, and r. de mot, j. bacteriol. 185:897-908, 2003). biocontrol strain pseudomonas fluorescens pf-5 contains two llpa-like genes, named llpa1(pf-5) and llpa2(pf-5). recombinant escherichia coli cells expressing llpa1(pf-5) or llpa2(pf-5) acquired bacteriocin activity and secreted a 31-kda prot ... | 2005 | 16151105 |
| prediction of gas-liquid mass transfer coefficient in sparged stirred tank bioreactors. | oxygen mass transfer in sparged stirred tank bioreactors has been studied. the rate of oxygen mass transfer into a culture in a bioreactor is affected by operational conditions and geometrical parameters as well as the physicochemical properties of the medium (nutrients, substances excreted by the micro-organism, and surface active agents that are often added to the medium) and the presence of the micro-organism. thus, oxygen mass transfer coefficient values in fermentation broths often differ s ... | 2005 | 16155951 |
| new media for the semiselective isolation and enumeration of xanthomonas campestris pv. mangiferaeindicae, the causal agent of mango bacterial black spot. | mango bacterial black spot, caused by xanthomonas campestris pv. mangiferaeindicae, is a potentially severe disease in several tropical and subtropical areas. data describing the life cycle of the pathogen are needed for improving integrated pest management strategies. because of the important bacterial microflora associated with mango leaves, isolation of the pathogen is often difficult using nonselective agar media. | 2005 | 16162231 |
| comparative genomic analysis reveals a novel mitochondrial isoform of human rts protein and unusual phylogenetic distribution of the rts gene. | the rts gene (enosf1), first identified in homo sapiens as a gene complementary to the thymidylate synthase (tyms) mrna, is known to encode two protein isoforms, rtsalpha and rtsbeta. the rtsbeta isoform appears to be an enzyme responsible for the synthesis of signaling molecules involved in the down-regulation of thymidylate synthase, but the exact cellular functions of rts genes are largely unknown. | 2005 | 16162288 |
| structure and function of the xpse n-terminal domain, an essential component of the xanthomonas campestris type ii secretion system. | secretion of fully folded extracellular proteins across the outer membrane of gram-negative bacteria is mainly assisted by the atp-dependent type ii secretion system (t2ss). depending on species, 12-15 proteins are usually required for the function of t2ss by forming a trans-envelope multiprotein secretion complex. here we report crystal structures of an essential component of the xanthomonas campestris t2ss, the 21-kda n-terminal domain of cytosolic secretion atpase xpse (xpsen), in two conform ... | 2005 | 16162504 |
| the alpha-(1-->6) glycosidic linkage as a novel conformational entropic regulator in osmoregulated periplasmic alpha-cyclosophorohexadecaose. | molecular dynamics simulations were performed to explain the conformational effect of an alpha-(1-->6)-glycosidic linkage upon the cyclic osmoregulated periplasmic glucan (opg) produced by xanthomonas campestris pv. citri. we suggest that a single alpha-(1-->6)-glycosidic linkage in cyclic opg functions as a novel entropic regulator, which reduces the conformational entropy of cyclic opg and increases the motional entropy of solvent water molecules. | 2005 | 16169537 |
| diversity in domain architectures of ser/thr kinases and their homologues in prokaryotes. | ser/thr/tyr kinases (styks) commonly found in eukaryotes have been recently reported in many bacterial species. recent studies elucidating their cellular functions have established their roles in bacterial growth and development. however functions of a large number of bacterial styks still remain elusive. the organisation of domains in a large dataset of bacterial styks has been investigated here in order to recognise variety in domain combinations which determine functions of bacterial styks. | 2005 | 16171520 |
| virulence deficiency caused by a transposon insertion in the purh gene of xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. we have identified a tn5-induced virulence-deficient mutant (bxo1704) of x. oryzae pv. oryzae. the bxo1704 mutant exhibited growth deficiency in minimal medium but was proficient in inducing a hypersensitive response in a non-host tomato plant. sequence analysis of the chromosomal dna flanking the tn5 insertion indicated that the tn5 insertion is in the purh gene, which is highly homologous to purh genes of ot ... | 2005 | 16175206 |
| mathematical design of prokaryotic clone-based microarrays. | clone-based microarrays, on which each spot represents a random genomic fragment, are a good alternative to open reading frame-based microarrays, especially for microorganisms for which the complete genome sequence is not available. since the generation of a genomic dna library is a random process, it is beforehand uncertain which genes are represented. nevertheless, the genome coverage of such an array, which depends on different variables like the insert size and the number of clones in the li ... | 2005 | 16191193 |
| myxoxanthophyll is required for normal cell wall structure and thylakoid organization in the cyanobacterium synechocystis sp. strain pcc 6803. | myxoxanthophyll is a carotenoid glycoside in cyanobacteria that is of unknown biological significance. the sugar moiety of myxoxanthophyll in synechocystis sp. strain pcc 6803 was identified as dimethyl fucose. the open reading frame sll1213 encoding a fucose synthetase orthologue was deleted to probe the role of fucose and to determine the biological significance of myxoxanthophyll in synechocystis sp. strain pcc 6803. upon deletion of sll1213, a pleiotropic phenotype was obtained: when propaga ... | 2005 | 16199557 |
| community structure and diversity of biofilms from a beer bottling plant as revealed using 16s rrna gene clone libraries. | the microbial composition of biofilms from a beer bottling plant was analyzed by a cultivation independent analysis of the 16s rrna genes. clone libraries were differentiated by amplified 16s rrna gene restriction analysis and representative clones from each group were sequenced. the diversity of the clone libraries was comparable with the diversity found for environmental samples. no evidences for the presence of strictly anaerobic taxa or important beer spoilers were found, indicating that bio ... | 2005 | 16204578 |
| the subsystems approach to genome annotation and its use in the project to annotate 1000 genomes. | the release of the 1000th complete microbial genome will occur in the next two to three years. in anticipation of this milestone, the fellowship for interpretation of genomes (fig) launched the project to annotate 1000 genomes. the project is built around the principle that the key to improved accuracy in high-throughput annotation technology is to have experts annotate single subsystems over the complete collection of genomes, rather than having an annotation expert attempt to annotate all of t ... | 2005 | 16214803 |
| phydbac "gene function predictor": a gene annotation tool based on genomic context analysis. | the large amount of completely sequenced genomes allows genomic context analysis to predict reliable functional associations between prokaryotic proteins. major methods rely on the fact that genes encoding physically interacting partners or members of shared metabolic pathways tend to be proximate on the genome, to evolve in a correlated manner and to be fused as a single sequence in another organism. | 2005 | 16221304 |
| differentiation of regions with atypical oligonucleotide composition in bacterial genomes. | complete sequencing of bacterial genomes has become a common technique of present day microbiology. thereafter, data mining in the complete sequence is an essential step. new in silico methods are needed that rapidly identify the major features of genome organization and facilitate the prediction of the functional class of orfs. we tested the usefulness of local oligonucleotide usage (ou) patterns to recognize and differentiate types of atypical oligonucleotide composition in dna sequences of ba ... | 2005 | 16225667 |
| alpha-anomer-selective glucosylation of menthol with high yield through a crystal accumulation reaction using lyophilized cells of xanthomonas campestris wu-9701. | l-menthyl alpha-d-glucopyranoside (alpha-meng) is a desirable derivative of l-menthol with useful properties for the production of new flavors and novel food additives. bacteria were screened for alpha-anomer-selective glucosylation activity toward l-menthol, resulting in the isolation of two strains, xanthomonas campestris wu-9701 and stenotrophomonas maltophilia wu-9702, from independent soil samples. since the safety of x. campestris for use in the food industry is well established, wu-9701 w ... | 2000 | 16232716 |
| alpha-anomer-selective glucosylation of (+)-catechin by the crude enzyme, showing glucosyl transfer activity, of xanthomonas campestris wu-9701. | alpha-anomer-selective glucosylation of (+)-catechin was carried out using the crude enzyme, showing alpha-glucose transferring activity, of xanthomonas campestris wu-9701 with maltose as a glucosyl donor. when 60 mg of (+)-catechin and 50 mg of the enzyme (5.25 units as maltose hydrolysing activity) were incubated in 10 ml of 10 mm citrate-na2hpo4 buffer (ph 6.5) containing 1.2 m maltose at 45 degrees c, only one (+)-catechin glucoside was selectively obtained as a product. the (+)-catechin glu ... | 2000 | 16232922 |
| enzymatic synthesis of alpha-arbutin by alpha-anomer-selective glucosylation of hydroquinone using lyophilized cells of xanthomonas campestris wu-9701. | alpha-arbutin, a useful cosmetic ingredient, was selectively synthesized by alpha-anomer-selective glucosylation of hydroquinone with maltose as a glucosyl donor using lyophilized cells of xanthomonas campestris wu-9701 as a biocatalyst. when 45 mm hydroquinone and 120 mg of lyophilized cells showing 11 nkat of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mm h3bo3naohkcl buffer (ph 7.5) containing 1.2 m maltose at 40 degrees c, only one form of hydroquinone glucoside was selectivel ... | 2002 | 16233209 |
| enzymatic synthesis of l-menthyl alpha-maltoside and l-menthyl alpha-maltooligosides from l-menthyl alpha-glucoside by cyclodextrin glucanotransferase. | l-menthyl alpha-d-glucopyranosyl-(1-->4)-alpha-d-glucopyranoside (alpha-meng2), a novel glycoside of l-menthol, was synthesized enzymatically and its physicochemical properties were characterized. production of alpha-meng2 from l-menthyl alpha-d-glucopyranoside (alpha-meng) was attempted since we had already succeeded in the high-yield production of alpha-meng using a xanthomonas campestris enzyme (nakagawa h., et al. j. biosci. bioeng., 89, 138-144, 2000). through production tests on enzymes, i ... | 2002 | 16233280 |
| selective alpha-glucosylation of eugenol by alpha-glucosyl transfer enzyme of xanthomonas campestris wu-9701. | for one-step enzymatic synthesis of eugenyl alpha-glucoside as a promising pro-drug for a hair restorer and a derivative of spices, selective alpha-glucosylation of eugenol was carried out using the alpha-glucosyl transfer enzyme of xanthomonas campestris wu-9701. when 130 micromol eugenol and crude enzyme showing 1.0 unit of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mm h3bo3-naoh-kcl buffer (ph 8.0) containing 1.2 m maltose as a glucosyl donor at 40 degrees c, only one form of ... | 2003 | 16233510 |
| insights into genome plasticity and pathogenicity of the plant pathogenic bacterium xanthomonas campestris pv. vesicatoria revealed by the complete genome sequence. | the gram-negative plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria is the causative agent of bacterial spot disease in pepper and tomato plants, which leads to economically important yield losses. this pathosystem has become a well-established model for studying bacterial infection strategies. here, we present the whole-genome sequence of the pepper-pathogenic xanthomonas campestris pv. vesicatoria strain 85-10, which comprises a 5.17-mb circular chromosome and four plasmids. th ... | 2005 | 16237009 |
| cpse from type 2 streptococcus pneumoniae catalyzes the reversible addition of glucose-1-phosphate to a polyprenyl phosphate acceptor, initiating type 2 capsule repeat unit formation. | the majority of the 90 capsule types made by the gram-positive pathogen streptococcus pneumoniae are assembled by a block-type mechanism similar to that utilized by the wzy-dependent o antigens and capsules of gram-negative bacteria. in this mechanism, initiation of repeat unit formation occurs by the transfer of a sugar to a lipid acceptor. in s. pneumoniae, this step is catalyzed by cpse, a protein conserved among the majority of capsule types. membranes from s. pneumoniae type 2 strain d39 an ... | 2005 | 16237026 |
| a study of archaeal enzymes involved in polar lipid synthesis linking amino acid sequence information, genomic contexts and lipid composition. | cellular membrane lipids, of which phospholipids are the major constituents, form one of the characteristic features that distinguish archaea from other organisms. in this study, we focused on the steps in archaeal phospholipid synthetic pathways that generate polar lipids such as archaetidylserine, archaetidylglycerol, and archaetidylinositol. only archaetidylserine synthase (ass), from methanothermobacter thermautotrophicus, has been experimentally identified. other enzymes have not been fully ... | 2005 | 16243780 |
| increased calcium levels and prolonged shelf life in tomatoes expressing arabidopsis h+/ca2+ transporters. | here we demonstrate that fruit from tomato (lycopersicon esculentum) plants expressing arabidopsis (arabidopsis thaliana) h(+)/cation exchangers (cax) have more calcium (ca2+) and prolonged shelf life when compared to controls. previously, using the prototypical cax1, it has been demonstrated that, in yeast (saccharomyces cerevisiae) cells, cax transporters are activated when the n-terminal autoinhibitory region is deleted, to give an n-terminally truncated cax (scax), or altered through specifi ... | 2005 | 16244156 |
| analysis of the cdnas of hypothetical genes on arabidopsis chromosome 2 reveals numerous transcript variants. | in the fully sequenced arabidopsis (arabidopsis thaliana) genome, many gene models are annotated as "hypothetical protein," whose gene structures are predicted solely by computer algorithms with no support from either expressed sequence matches from arabidopsis, or nucleic acid or protein homologs from other species. in order to confirm their existence and predicted gene structures, a high-throughput method of rapid amplification of cdna ends (race) was used to obtain their cdna sequences from 1 ... | 2005 | 16244158 |
| biological control of bacterial spot of tomato caused by xanthomonas campestris pv. vesicatoria by rahnella aquatilis. | xanthomonas campestris pv. vesicatoria strain 2 was isolated from infected tomato seedlings grown in open field in egypt. this strain produced irregular yellow-necrotic areas on tomato leaves and spotting of the stem. in an attempt to control this disease biologically, four experiments were conducted and tomato seedlings were pretreated, before the pathogen, with either of two antagonistic strains of rahnella aquatilis through leaves, roots, soil or seeds. in all experiments, seedlings pretreate ... | 2005 | 16255138 |
| different catalytic mechanisms in mammalian selenocysteine- and cysteine-containing methionine-r-sulfoxide reductases. | selenocysteine (sec) is found in active sites of several oxidoreductases in which this residue is essential for catalytic activity. however, many selenoproteins have fully functional orthologs, wherein cysteine (cys) occupies the position of sec. the reason why some enzymes evolve into selenoproteins if the cys versions may be sufficient is not understood. among three mammalian methionine-r-sulfoxide reductases (msrbs), msrb1 is a sec-containing protein, whereas msrb2 and msrb3 contain cys in th ... | 2005 | 16262444 |
| novel virulence gene of pseudomonas syringae pv. tomato strain dc3000. | previously, we conducted a mutant screen of pseudomonas syringae pv. tomato strain dc3000 to identify genes that contribute to virulence on arabidopsis thaliana plants. here we describe the characterization of one mutant strain, db4h2, which contains a single tn5 insertion in pspto3576, an open reading frame that is predicted to encode a protein belonging to the tetr family of transcriptional regulators. we demonstrate that pspto3576 is necessary for virulence in dc3000 and designate the encoded ... | 2005 | 16267304 |
| rhodopseudomonas palustris regulons detected by cross-species analysis of alphaproteobacterial genomes. | rhodopseudomonas palustris, an alpha-proteobacterium, carries out three of the chemical reactions that support life on this planet: the conversion of sunlight to chemical-potential energy; the absorption of carbon dioxide, which it converts to cellular material; and the fixation of atmospheric nitrogen into ammonia. insight into the transcription-regulatory network that coordinates these processes is fundamental to understanding the biology of this versatile bacterium. with this goal in mind, we ... | 2005 | 16269786 |
| first synthesis of the beta-d-rhamnosylated trisaccharide repeating unit of the o-antigen from xanthomonas campestris pv. campestris 8004. | the trisaccharide repeating unit of the o-antigen of the lipopolysaccharide from xanthomonas campestris pv. campestris 8004, a pathogen of cruciferous crops, presents some structural features that renders it a challenging synthetic target: the presence of a beta-d-rhamnosidic linkage, the steric crowd on a 1,2-cis-diglycosylated d-rhamnose, and finally the noncommercial availability of its monosaccharide constituents. the synthesis of this trisaccharide as methyl glycoside has been accomplished ... | 2005 | 16277328 |
| exploration of phylogenetic data using a global sequence analysis method. | molecular phylogenetic methods are based on alignments of nucleic or peptidic sequences. the tremendous increase in molecular data permits phylogenetic analyses of very long sequences and of many species, but also requires methods to help manage large datasets. | 2005 | 16280081 |
| genome-wide transcriptional analysis of the phosphate starvation stimulon of bacillus subtilis. | bacillus subtilis responds to phosphate starvation stress by inducing the phop and sigb regulons. while the phop regulon provides a specific response to phosphate starvation stress, maximizing the acquisition of phosphate (p(i)) from the environment and reducing the cellular requirement for this essential nutrient, the sigb regulon provides nonspecific resistance to stress by protecting essential cellular components, such as dna and membranes. we have characterized the phosphate starvation stres ... | 2005 | 16291680 |
| identification of erwinia amylovora genes induced during infection of immature pear tissue. | the enterobacterium erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. in this study, we used a modified in vivo expression technology system to identify e. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. we identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes a ... | 2005 | 16291682 |
| evaluation of the antimicrobial activities of plant oxylipins supports their involvement in defense against pathogens. | plant oxylipins are a large family of metabolites derived from polyunsaturated fatty acids. the characterization of mutants or transgenic plants affected in the biosynthesis or perception of oxylipins has recently emphasized the role of the so-called oxylipin pathway in plant defense against pests and pathogens. in this context, presumed functions of oxylipins include direct antimicrobial effect, stimulation of plant defense gene expression, and regulation of plant cell death. however, the preci ... | 2005 | 16299186 |