| a synonymous mutation in yersinia enterocolitica yope affects the function of the yope type iii secretion signal. | yersinia spp. inject virulence proteins called yops into the cytosol of target eukaryotic cells in an effort to evade phagocytic killing via a dedicated protein-sorting pathway termed type iii secretion. previous studies have proposed that, unlike other protein translocation mechanisms, yops are not recognized as substrates for secretion via a solely proteinaceous signal. rather, at least some of this information may be encoded within yop mrna. herein, we report that the first seven codons of yo ... | 2005 | 15629941 |
| evidence for two flagellar stators and their role in the motility of pseudomonas aeruginosa. | pseudomonas aeruginosa is a ubiquitous bacterium capable of twitching, swimming, and swarming motility. in this study, we present evidence that p. aeruginosa has two flagellar stators, conserved in all pseudomonads as well as some other gram-negative bacteria. either stator is sufficient for swimming, but both are necessary for swarming motility under most of the conditions tested, suggesting that these two stators may have different roles in these two types of motility. | 2005 | 15629949 |
| protection of xanthomonas against arsenic toxicity involves the peroxide-sensing transcription regulator oxyr. | arsenic has been shown to mediate its toxicity through induced generation of reactive oxygen species. here, we examined the role of oxidative stress-inducible genes (kata, ahpc and ohr) and their regulators (oxyr and ohrr) in the response to arsenic treatment in a plant pathogenic bacterium, xanthomonas campestris pv. phaseoli (xp). overproduction of peroxide-scavenging enzymes (kata, ahpcf and ohr) did not enhance arsenic tolerance in wild-type xp. furthermore, inactivation of kata, ahpc, ohr, ... | 2005 | 15636745 |
| diversity of green-like and red-like ribulose-1,5-bisphosphate carboxylase/oxygenase large-subunit genes (cbbl) in differently managed agricultural soils. | a pcr-based approach was developed to detect ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) form i large-subunit genes (cbbl) as a functional marker of autotrophic bacteria that fix carbon dioxide via the calvin-benson-bassham cycle. we constructed two different primer sets, targeting the green-like and red-like phylogenetic groups of cbbl genes. the diversity of these cbbl genes was analyzed by the use of three differently managed agricultural soils from a long-term field experiment. ... | 2005 | 15640185 |
| a clp gene homologue belonging to the crp gene family globally regulates lytic enzyme production, antimicrobial activity, and biological control activity expressed by lysobacter enzymogenes strain c3. | lysobacter enzymogenes strain c3, a biological control agent for plant diseases, produces multiple extracellular hydrolytic enzymes and displays antimicrobial activity against various fungal and oomycetous species. however, little is known about the regulation of these enzymes or their roles in antimicrobial activity and biocontrol. a study was undertaken to identify mutants of strain c3 affected in extracellular enzyme production and to evaluate their biocontrol efficacy. a single mini-tn5-lacz ... | 2005 | 15640196 |
| sensitive and specific detection of xanthomonas campestris pv campestris by pcr using species-specific primers based on hrpf gene sequences. | a sensitive and specific assay was developed to detect bacterial black rot of crucifers caused by xanthomonas campestris pv. campestris (x. c. pv. campestris), in cabbage seed and plant. primers xcf and xcr from hrpf homologous to nolx, host recognition protein, were used to amplify a 525 bp dna fragment. pcr technique was applied to detect the pathogen in naturally infected seed and plant of cabbage. the pcr product was only produced from x. c. pv. campestris among 40 isolates of xanthomonas st ... | 2004 | 15646387 |
| in silico analysis of nonribosomal peptide synthetases of xanthomonas axonopodis pv. citri: identification of putative siderophore and lipopeptide biosynthetic genes. | the genomes of the plant pathogens xanthomonas axonopodis (xac) and xanthomonas campestris (xcc) were analysed with the aim of deducing their ability to produce nonribosomal peptides. nonribosomal peptide synthetase (nrps) genes were identified in two separate loci of xac. while the genes of locus 1 are common to both strains, locus 2 was only found in xac. dissection and phylogenetic analysis of the condensation and thioesterase domains of the nrpss of loci 1 and 2 of xac revealed homology, res ... | 2004 | 15646388 |
| induction of rapid detachment in shewanella oneidensis mr-1 biofilms. | active detachment of cells from microbial biofilms is a critical yet poorly understood step in biofilm development. we discovered that detachment of cells from biofilms of shewanella oneidensis mr-1 can be induced by arresting the medium flow in a hydrodynamic biofilm system. induction of detachment was rapid, and substantial biofilm dispersal started as soon as 5 min after the stop of flow. we developed a confocal laser scanning microscopy-based assay to quantify detachment. the extent of bioma ... | 2005 | 15659679 |
| expression profiling of virulence and pathogenicity genes of xanthomonas axonopodis pv. citri. | dna macroarrays of 279 genes of xanthomonas axonopodis pv. citri potentially associated with pathogenicity and virulence were used to compare the transcriptional alterations of this bacterium in response to two synthetic media. data analysis indicated that 31 genes were up-regulated by synthetic medium xvm2, while only 7 genes were repressed. the results suggest that xvm2 could be used as an in vitro system to identify candidate genes involved in pathogenesis of x. axonopodis pv. citri. | 2005 | 15659697 |
| antibacterial activity of seed proteins of robinia pseudoacacia. | a low molecular weight cationic peptide was isolated from robinia pseudoacacia seed and tested in vitro against seven bacteria (corynebacterium michiganense, staphylococcus aureus, bacillus subtilis, erwinia carotovora subsp. carotovora, pseudomonas syringae pv syringae, xanthomonas campestris pv campestris, and escherichia coli). the peptide inhibited the growth of the tested strains. the effective concentrations required for 50% inhibition of bacterial growth ranged between 20 and 120 microg m ... | 2005 | 15664465 |
| the genome sequence of xanthomonas oryzae pathovar oryzae kacc10331, the bacterial blight pathogen of rice. | the nucleotide sequence was determined for the genome of xanthomonas oryzae pathovar oryzae (xoo) kacc10331, a bacterium that causes bacterial blight in rice (oryza sativa l.). the genome is comprised of a single, 4 941 439 bp, circular chromosome that is g + c rich (63.7%). the genome includes 4637 open reading frames (orfs) of which 3340 (72.0%) could be assigned putative function. orthologs for 80% of the predicted xoo genes were found in the previously reported x.axonopodis pv. citri (xac) a ... | 2005 | 15673718 |
| molecular characterization of proteolytic cleavage sites of the pseudomonas syringae effector avrrpt2. | during infection of arabidopsis thaliana, the bacterium pseudomonas syringae pv tomato delivers the effector protein avrrpt2 into the plant cell cytosol. within the plant cell, avrrpt2 undergoes n-terminal processing and causes elimination of arabidopsis rin4. previous work established that avrrpt2 is a putative cysteine protease, and avrrpt2 processing and rin4 elimination require an intact predicted catalytic triad in that avrrpt2. in this work, proteolytic events that depend on avrrpt2 activi ... | 2005 | 15684089 |
| expression of heat-shock genes groesl in xanthomonas campestris is upregulated by clp in an indirect manner. | clp is a homologue of cyclic amp-receptor protein in xanthomonas campestris. in this study, proteomic analysis and western blotting showed that the clp mutant (tc820) of x. campestris synthesizes less groesl proteins than the parental p20h. the groesl upstream regions, nt -583 to -32 (552 bp) and nt -178 to -29 (150 bp) relative to the groesl initiation codon, were cloned for transcriptional fusion assays. the 150-bp region, bearing putative sigma24- and sigma32-binding sites and the circe eleme ... | 2005 | 15686836 |
| regulation of resistance to copper in xanthomonas axonopodis pv. vesicatoria. | copper-resistant strains of xanthomonas axonopodis pv. vesicatoria were previously shown to carry plasmid-borne copper resistance genes related to the cop and pco operons of pseudomonas syringae and escherichia coli, respectively. however, instead of the two-component (coprs and pcors) systems determining copper-inducible expression of the operons in p. syringae and e. coli, a novel open reading frame, copl, was found to be required for copper-inducible expression of the downstream multicopper o ... | 2005 | 15691931 |
| genetic and physiological analysis of the major oxyr-regulated kata from xanthomonas campestris pv. phaseoli. | kata encodes the major catalase that accounts for 90 % of the total catalase activity present in xanthomonas campestris pv. phaseoli. kata is located upstream of an orf designated anka encoding a cytoplasmic membrane protein homologous to eukaryotic ankyrin. transcriptional analysis of kata and anka identified two kata transcripts: a major monocistronic kata transcript and a minor bicistronic kata-anka transcript. kata expression was induced in the presence of various oxidants including h2o2, or ... | 2005 | 15699208 |
| protein domains and architectural innovation in plant-associated proteobacteria. | evolution of new complex biological behaviour tends to arise by novel combinations of existing building blocks. the functional and evolutionary building blocks of the proteome are protein domains, the function of a protein being dependent on its constituent domains. we clustered completely-sequenced proteomes of prokaryotes on the basis of their protein domain content, as defined by pfam (release 16.0). this revealed that, although there was a correlation between phylogeny and domain content, ot ... | 2005 | 15715905 |
| pseudomonas aeruginosa fiml regulates multiple virulence functions by intersecting with vfr-modulated pathways. | virulence of pseudomonas aeruginosa involves the co-ordinate expression of a range of factors including type iv pili (tfp), the type iii secretion system (ttss) and quorum sensing. tfp are required for twitching motility, efficient biofilm formation, and for adhesion and type iii secretion (tts)-mediated damage to mammalian cells. we describe a novel gene (fiml) that is required for tfp biogenesis and function, for tts and for normal biofilm development in p. aeruginosa. the predicted product of ... | 2005 | 15720546 |
| endocytosis of xanthomonas campestris pathovar campestris lipopolysaccharides in non-host plant cells of nicotiana tabacum. | the specific recognition of phytopathogenic bacteria by plant cells is generally mediated by a number of signal molecules. the elicitor-active lipopolysaccharides (lps) of the phytopathogenic bacterium xanthomonas campestris pv. campestris (x.c.c) are recognized by its non-host plant nicotiana tabacum (n.t.). this lps was purified and labelled with fluorescein isothiocyanate (fitc) for monitoring the fate of these signal molecules in intact plant cells of tobacco. in this study we were able to s ... | 2005 | 15720635 |
| structural analyses of novel glycerophosphorylated alpha-cyclosophorohexadecaoses isolated from x. campestris pv. campestris. | novel periplasmic anionic cyclic glucans produced by xanthomonas campestris pv. campestris were isolated by trichloroacetic acid treatment and various chromatographic techniques. no report has been made on the presence of substituted cyclic glucans of the xanthomonas species. we show, for the first time, that x. campestris pv. campestris produces the anionic cyclic glucans with phosphoglycerol residues, the presence of which can be predicted by analyzing the sequence database with the aid of the ... | 2005 | 15721339 |
| molecular and biochemical characterization of an endo-beta-1,3-glucanase from the pinewood nematode bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria. | we report the cloning and functional characterization of an endo-beta-1,3-glucanase from the pinewood nematode bursaphelenchus xylophilus acquired by horizontal gene transfer from bacteria. this is the first gene of this type from any nematode species. we show that a similar cdna is also present in another closely related species b. mucronatus, but that similar sequences are not present in any other nematode studied to date. the b. xylophilus gene is expressed solely in the oesophageal gland cel ... | 2005 | 15727561 |
| variation in the strength of selected codon usage bias among bacteria. | among bacteria, many species have synonymous codon usage patterns that have been influenced by natural selection for those codons that are translated more accurately and/or efficiently. however, in other species selection appears to have been ineffective. here, we introduce a population genetics-based model for quantifying the extent to which selection has been effective. the approach is applied to 80 phylogenetically diverse bacterial species for which whole genome sequences are available. the ... | 2005 | 15728743 |
| induction of some defense-related genes and oxidative burst is required for the establishment of systemic acquired resistance in capsicum annuum. | the inoculation of primary pepper leaves with an avirulent strain of xanthomonas campestris pv. vesicatoria induced systemic acquired resistance (sar) in the non-inoculated, secondary leaves. this sar response was accompanied by the systemic expression of the defense-related genes, a systemic microoxidative burst generating h2o2, and the systemic induction of both ion-leakage and callose deposition in the non-inoculated, secondary leaves. some defense-related genes including those encoding pr-1, ... | 2005 | 15729568 |
| crystal structure of n-acetylornithine transcarbamylase from xanthomonas campestris: a novel enzyme in a new arginine biosynthetic pathway found in several eubacteria. | we have identified in xanthomonas campestris a novel n-acetylornithine transcarbamylase that replaces ornithine transcarbamylase in the canonic arginine biosynthetic pathway of several eubacteria. the crystal structures of the protein in the presence and absence of the reaction product, n-acetylcitrulline, were determined. this new family of transcarbamylases lacks the dxxsmg motif that is characteristic of all ornithine transcarbamylases (otcases) and contains a novel proline-rich loop that for ... | 2005 | 15731101 |
| powerful screens for bacterial virulence proteins. | | 2005 | 15738387 |
| the conserved xanthomonas campestris pv. vesicatoria effector protein xopx is a virulence factor and suppresses host defense in nicotiana benthamiana. | nicotiana benthamiana leaves display a visible plant cell death response when infiltrated with a high titer inoculum of the non-host pathogen, xanthomonas campestris pv. vesicatoria (xcv). this visual phenotype was used to identify overlapping cosmid clones from a genomic cosmid library constructed from the xcv strain, gm98-38. individual cosmid clones from the xcv library were conjugated into x. campestris pv. campestris (xcc) and exconjugants were scored for an altered visual high titer inocul ... | 2005 | 15743446 |
| comparative genomic analysis of the ppt23a plasmid family of pseudomonas syringae. | members of the ppt23a plasmid family of pseudomonas syringae play an important role in the interaction of this bacterial pathogen with host plants. complete sequence analysis of several ppt23a family plasmids (pfps) has provided a glimpse of the gene content and virulence function of these plasmids. we constructed a macroarray containing 161 genes to estimate and compare the gene contents of 23 newly analyzed and eight known pfps from 12 pathovars of p. syringae, which belong to four genomospeci ... | 2005 | 15743960 |
| biosynthesis of auxin by the gram-positive phytopathogen rhodococcus fascians is controlled by compounds specific to infected plant tissues. | the role and metabolism of indole-3-acetic acid in gram-negative bacteria is well documented, but little is known about indole-3-acetic acid biosynthesis and regulation in gram-positive bacteria. the phytopathogen rhodococcus fascians, a gram-positive organism, incites diverse developmental alterations, such as leafy galls, on a wide range of plants. phenotypic analysis of a leafy gall suggests that auxin may play an important role in the development of the symptoms. we show here for the first t ... | 2005 | 15746315 |
| poly(a) polymerase modification and reverse transcriptase pcr amplification of environmental rna. | we describe a combination of two established techniques for a novel application for constructing full-length cdna clone libraries from environmental rna. the cdna was cloned without the use of prescribed primers that target specific genes, and the procedure did not involve random priming. purified rna was first modified by addition of a poly(a) tail and then was amplified by using a commercially available reverse transcriptase pcr (rt-pcr) cdna synthesis kit. to demonstrate the feasibility of th ... | 2005 | 15746328 |
| isolation and characterization of novel giant stenotrophomonas maltophilia phage phisma5. | stenotrophomonas maltophilia is one of the most prevalent opportunistic bacteria causing nosocomial infections. it has become problematic because most of the isolates are resistant to multiple antibiotics, and therefore, development of phage therapy has attracted strong attention. in this study, eight s. maltophilia phages were isolated from clinical samples including patient specimens, catheter-related devices, and wastewater. these phages can be divided into four distinct groups based on host ... | 2005 | 15746341 |
| genomic analysis of bacteriophage phijl001: insights into its interaction with a sponge-associated alpha-proteobacterium. | bacteriophage phijl001 infects a novel marine bacterium in the alpha subclass of the proteobacteria isolated from the marine sponge ircinia strobilina. phijl001 is a siphovirus and forms turbid plaques on its host. the genome sequence of phijl001 was determined in order to better understand the interaction between the marine phage and its sponge-associated host bacterium. the complete genome sequence of phijl001 comprised 63,469 bp with an overall g+c content of 62%. the genome has 91 predicted ... | 2005 | 15746365 |
| molecular genetic evidence for the role of sgt1 in the intramolecular complementation of bs2 protein activity in nicotiana benthamiana. | pepper plants (capsicum annuum) containing the bs2 resistance gene are resistant to strains of xanthomonas campestris pv vesicatoria (xcv) expressing the bacterial effector protein avrbs2. avrbs2 is delivered directly to the plant cell via the type iii protein secretion system (ttss) of xcv. upon recognition of avrbs2 by plants expressing the bs2 gene, a signal transduction cascade is activated leading to a bacterial disease resistance response. here, we describe a novel pathosystem that consist ... | 2005 | 15749757 |
| integrons in xanthomonas: a source of species genome diversity. | integrons are best known for assembling antibiotic resistance genes in clinical bacteria. they capture genes by using integrase-mediated site-specific recombination of mobile gene cassettes. integrons also occur in the chromosomes of many bacteria, notably beta- and gamma-proteobacteria. in a survey of xanthomonas, integrons were found in all 32 strains representing 12 pathovars of two species. their chromosomal location was downstream from the acid dehydratase gene, ilvd, suggesting that an int ... | 2005 | 15755815 |
| detection of and response to signals involved in host-microbe interactions by plant-associated bacteria. | diverse interactions between hosts and microbes are initiated by the detection of host-released chemical signals. detection of these signals leads to altered patterns of gene expression that culminate in specific and adaptive changes in bacterial physiology that are required for these associations. this concept was first demonstrated for the members of the family rhizobiaceae and was later found to apply to many other plant-associated bacteria as well as to microbes that colonize human and anima ... | 2005 | 15755957 |
| the capsular polysaccharide biosynthesis of streptococcus pneumoniae serotype 8: functional identification of the glycosyltransferase wcis (cap8h). | cps (capsular polysaccharide) is a major virulence factor in streptococcus pneumoniae. biosynthesis of cps ru (repeat unit) proceeds by sequential transfer of sugar residues from the appropriate sugar donor to an activated lipid carrier by committed gts (glycosyltransferases). while the nucleotide sequence of many cps loci is already known, the real substrate specificity of the hypothetical gts, as well as the sequence of sugar addition is unclear. in the present paper, we report the biochemical ... | 2005 | 15766331 |
| nmr structure note--solution structure of a bacterial bola-like protein xc975 from a plant pathogen xanthomonas campestris pv. campestris. | | 2005 | 15772757 |
| pseudoxanthomonas koreensis sp. nov. and pseudoxanthomonas daejeonensis sp. nov. | gram-negative, non-spore-forming, rod-shaped bacteria, t7-09(t) and tr6-08(t), were isolated from soil from a ginseng field in south korea and characterized to determine their taxonomic position. 16s rrna gene sequence analysis showed that the two isolates shared 99.5 % sequence similarity. strains t7-09(t) and tr6-08(t) were shown to belong to the proteobacteria and showed the highest levels of sequence similarity to pseudoxanthomonas broegbernensis dsm 12573(t) (98.1 %), pseudoxanthomonas mexi ... | 2005 | 15774663 |
| identification of a tcpc-tcpq outer membrane complex involved in the biogenesis of the toxin-coregulated pilus of vibrio cholerae. | the toxin-coregulated pilus (tcp) of vibrio cholerae and the soluble tcpf protein that is secreted via the tcp biogenesis apparatus are essential for intestinal colonization. the tcp biogenesis apparatus is composed of at least nine proteins but is largely uncharacterized. tcpc is an outer membrane lipoprotein required for tcp biogenesis that is a member of the secretin protein superfamily. in the present study, analysis of tcpc in a series of strains deficient in each of the tcp biogenesis prot ... | 2005 | 15774863 |
| effects on promoter activity of base substitutions in the cis-acting regulatory element of hrpxo regulons in xanthomonas oryzae pv. oryzae. | in xanthomonas oryzae pv. oryzae, the causal agent of bacterial leaf blight of rice, hrpxo is known to be a transcriptional regulator for the hypersensitive response and pathogenicity (hrp) genes. several hrpxo regulons are preceded by a consensus sequence (ttcgc-n(15)-ttcgc), called the plant-inducible promoter (pip) box, which is required for expression of the gene that follows. thus, the pip box can be an effective marker for screening hrpxo regulons from the genome database. it is not known, ... | 2005 | 15774873 |
| identification of new protein-protein interactions involving the products of the chromosome- and plasmid-encoded type iv secretion loci of the phytopathogen xanthomonas axonopodis pv. citri. | the recently sequenced genome of the bacterial plant pathogen xanthomonas axonopodis pv. citri contains two virb gene clusters, one on the chromosome and one on a 64-kb plasmid, each of which codes for a previously uncharacterized type iv secretion system (t4ss). here we used a yeast two-hybrid assay to identify protein-protein interactions in these two systems. our results revealed interactions between known t4ss components as well as previously uncharacterized interactions involving hypothetic ... | 2005 | 15774874 |
| the type iii-dependent hrp pilus is required for productive interaction of xanthomonas campestris pv. vesicatoria with pepper host plants. | the plant pathogenic bacterium xanthomonas campestris pv. vesicatoria expresses a type iii secretion system that is necessary for both pathogenicity in susceptible hosts and the 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. here we show that x. campestris pv. vesicatoria produces filamentous structures, the hrp pili, at the cell surface under hrp-inducing ... | 2005 | 15774889 |
| caalaat1 catalyzes the alanine: 2-oxoglutarate aminotransferase reaction during the resistance response against tobacco mosaic virus in hot pepper. | hot pepper (capsicum annuum l. cv. bugang) plants exhibit a hypersensitive response (hr) upon infection by tobacco mosaic virus (tmv) pathotype p0. to elucidate molecular mechanism that underlies this resistance, hot pepper cv. bugang leaves were inoculated with tmv-p0 and genes specifically up-regulated during the hr were isolated by differential screening. one of the clones, caalaat1 encoding a putative alanine aminotransferase (ec 2.6.1.2) exhibited organ-specific expression pattern and the t ... | 2005 | 15782348 |
| functional insights from the distribution and role of homopeptide repeat-containing proteins. | expansion of "low complex" repeats of amino acids such as glutamine (poly-q) is associated with protein misfolding and the development of degenerative diseases such as huntington's disease. the mechanism by which such regions promote misfolding remains controversial, the function of many repeat-containing proteins (rcps) remains obscure, and the role (if any) of repeat regions remains to be determined. here, a web-accessible database of rcps is presented. the distribution and evolution of rcps t ... | 2005 | 15805494 |
| comprehensive characterization of the contribution of individual sigb-dependent general stress genes to stress resistance of bacillus subtilis. | the sigma(b)-dependent general stress regulon of bacillus subtilis comprises more than 150 members. induction of this regulon by imposition of environmental or metabolic stress confers multiple, nonspecific, and preemptive stress resistance to nongrowing, nonsporulated cells of b. subtilis. in this study we performed a regulon-wide phenotypic screening analysis to determine the stress sensitivity profiles of 94 mutants defective in candidate members of the general stress regulon that were previo ... | 2005 | 15805528 |
| comparative analyses of xanthomonas and xylella complete genomes. | computational analyses of four bacterial genomes of the xanthomonadaceae family reveal new unique genes that may be involved in adaptation, pathogenicity, and host specificity. the xanthomonas genus presents 3636 unique genes distributed in 1470 families, while xylella genus presents 1026 unique genes distributed in 375 families. among xanthomonas-specific genes, we highlight a large number of cell wall degrading enzymes, proteases, and iron receptors, a set of energy metabolism genes, second co ... | 2005 | 15805778 |
| dimerization of the bacterial effector protein avrbs3 in the plant cell cytoplasm prior to nuclear import. | the effector protein avrbs3 from the bacterial phytopathogen xanthomonas campestris pv. vesicatoria is translocated into the plant cell where it specifically induces hypertrophy symptoms or the hypersensitive reaction. activity of avrbs3 depends on nuclear localization signals (nlss) and an acidic activation domain, suggesting a role in regulation of plant transcription. here, we show that avrbs3 dimerizes in the plant cell prior to its nuclear import. avrbs3 deletion derivatives were tested in ... | 2005 | 15807781 |
| co-evolution of trna 3' trailer sequences with 3' processing enzymes in bacteria. | maturation of the trna 3' terminus is a complicated process in bacteria. usually, it is initiated by an endonucleolytic cleavage carried out by rnase e and z in different bacteria. in escherichia coli, rnase e cleaves au-rich sequences downstream of trna, producing processing intermediates with a few extra residues at the 3' end; these are then removed by exoribonuclease trimming to generate the mature 3' end. here we show that essentially all e. coli trna precursors contain a potential rnase e ... | 2005 | 15811923 |
| exposure to cadmium elevates expression of genes in the oxyr and ohrr regulons and induces cross-resistance to peroxide killing treatment in xanthomonas campestris. | cadmium is an important heavy metal pollutant. for this study, we investigated the effects of cadmium exposure on the oxidative stress responses of xanthomonas campestris, a soil and plant pathogenic bacterium. the exposure of x. campestris to low concentrations of cadmium induces cross-protection against subsequent killing treatments with either h2o2 or the organic hydroperoxide tert-butyl hydroperoxide (tbooh), but not against the superoxide generator menadione. the cadmium-induced resistance ... | 2005 | 15812010 |
| xanthomonas axonopodis pv. phaseoli var. fuscans is aggregated in stable biofilm population sizes in the phyllosphere of field-grown beans. | the occurrence of "xanthomonas axonopodis pv. phaseoli var. fuscans" (proposed name) populations as biofilms on bean leaves was investigated during three field experiments on plots established with naturally contaminated bean seeds. behavior of aggregated versus solitary populations was determined by quantification of culturable cells in different fractions of the epiphytic population separated by particle size. x. axonopodis pv. phaseoli var. fuscans population dynamic studies confirmed an asym ... | 2005 | 15812033 |
| characterization of a mobile clpl gene from lactobacillus rhamnosus. | two genes encoding clpl atpase proteins were identified in a probiotic lactobacillus rhamnosus strain, e-97800. sequence analyses revealed that the genes, designated clpl1 and clpl2, share 80% identity. the clpl2 gene showed the highest degree of identity (98.5%) to a clpl gene from lactobacillus plantarum wcfsi, while it was not detected in three other l. rhamnosus strains studied. according to northern analyses, the expression of clpl1 and the clpl2 were induced during heat shock by > 20- and ... | 2005 | 15812039 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |