Publications

erwinia amylovora secretes dspe, a pathogenicity factor and functional avre homolog, through the hrp (type iii secretion) pathway.	erwinia amylovora was shown to secrete dspe, a pathogenicity factor of 198 kda and a functional homolog of avre of pseudomonas syringae pv. tomato. dspe was identified among the supernatant proteins isolated from cultures grown in an hrp gene-inducing minimal medium by immunodetection with a dspe-specific antiserum. secretion required an intact hrp pathway.	1998	9555912
ptn5cat: a tn5-derived genetic element to facilitate insertion mutagenesis, promoter probing, physical mapping, cloning, and marker exchange in phytopathogenic and other gram-negative bacteria.	a tn5-derived mobile element has been constructed to identify genes and promoters related to pathogenesis and virulence in pseudomonas syringae pv. phaseolicola. to enhance the rate of mutation this tn5 derivative was constructed carrying a mutant transposase which was placed in cis to the transposable element, but just outside the inverted repeats, therefore eliminating secondary transposition and increasing the stability of the insertion. the new element also contains a promoterless cat (chlor ...	1998	9571137
sequence analysis and expression of the filamentous phage phi lf gene i encoding a 48-kda protein associated with host cell membrane.	one viral strand of phi lf, a filamentous phage of xanthomonas campestris pv.campestris, the open reading frame (orf440) behind gene vi was identified as gene i. this gene codes for pi protein (440 aa, 48 kda) which was shown to be membrane-bound in the phi lf-infected host cell by western blot analysis using the antibody raised against the protein expressed in escherichia coli. its predicted amino acid sequence has a nucleotide-binding motif in the n-terminal 97 aa and a membrane-spanning domai ...	1998	9571147
a transposable partitioning locus used to stabilize plasmid-borne hydrogen oxidation and trifolitoxin production genes in a sinorhizobium strain.	improved nitrogen-fixing inoculum strains for leguminous crops must be able to effectively compete with indigenous strains for nodulation, enhance legume productivity compared to the productivity obtained with indigenous strains, and maintain stable expression of any added genes in the absence of selection pressure. we constructed a transposable element containing the tfx region for expression of increased nodulation competitiveness and the par locus for plasmid stability. the transposon was ins ...	1998	9572932
distribution of xanthomonas oryzae pv. oryzae dna modification systems in asia.	the presence or absence of two dna modification systems, xori and xorii, in 195 strains of xanthomonas oryzae pv. oryzae collected from different major rice-growing countries of asia was assessed. all four possible phenotypes (xori+ xorii+, xori+ xorii-, xori- xorii+ and xori- xorii-) were detected in the population at a ratio of approximately 1:2:2:2. the xori+ xorii+ and xori- xorii+ phenotypes were observed predominantly in strains from southeast asia (philippines, malaysia, and indonesia), w ...	1998	9572933
new bradyrhizobium japonicum strains that possess high copy numbers of the repeated sequence rs alpha.	in a survey of dna fingerprints of indigenous bradyrhizobium japonicum with the species-specific repeated sequences rs alpha and rs beta, 21 isolates from three field sites showed numerous rs-specific hybridization bands. the isolates were designated highly reiterated sequence-possessing (hrs) isolates, and their dna hybridization profiles were easily distinguished from the normal patterns. some hrs isolates from two field sites possessed extremely high numbers of rs alpha copies, ranging from 8 ...	1998	9572961
cell-contact-stimulated formation of filamentous appendages by salmonella typhimurium does not depend on the type iii secretion system encoded by salmonella pathogenicity island 1.	the formation of filamentous appendages on salmonella typhimurium has been implicated in the triggering of bacterial entry into host cells (c. c. ginocchio, s. b. olmsted, c. l. wells, and j. e. galán, cell 76:717-724, 1994). we have examined the roles of cell contact and salmonella pathogenicity island 1 (spi1) in appendage formation by comparing the surface morphologies of a panel of s. typhimurium strains adherent to tissue culture inserts, to cultured epithelial cell lines, and to murine int ...	1998	9573083
identification and characterization of a new organic hydroperoxide resistance (ohr) gene with a novel pattern of oxidative stress regulation from xanthomonas campestris pv. phaseoli.	we have isolated a new organic hydroperoxide resistance (ohr) gene from xanthomonas campestris pv. phaseoli. this was done by complementation of an escherichia coli alkyl hydroperoxide reductase mutant with an organic hydroperoxide-hypersensitive phenotype. ohr encodes a 14.5-kda protein. its amino acid sequence shows high homology with several proteins of unknown function. an ohr mutant was subsequently constructed, and it showed increased sensitivity to both growth-inhibitory and killing conce ...	1998	9573147
isolation and characterization of three streptococcus pneumoniae transformation-specific loci by use of a lacz reporter insertion vector.	although more than a dozen new proteins are produced when streptococcus pneumoniae cells become competent for genetic transformation, only a few of the corresponding genes have been identified to date. to find genes responsible for the production of competence-specific proteins, a random lacz transcriptional fusion library was constructed in s. pneumoniae by using the insertional lacz reporter vector pevp3. screening the library for clones with competence-specific beta-galactosidase (beta-gal) p ...	1998	9573156
molecular characterization of the oxalate oxidase involved in the response of barley to the powdery mildew fungus.	previously we reported that oxalate oxidase activity increases in extracts of barley (hordeum vulgare) leaves in response to the powdery mildew fungus (blumeria [syn. erysiphe] graminis f.sp. hordei) and proposed this as a source of h2o2 during plant-pathogen interactions. in this paper we show that the n terminus of the major pathogen-response oxalate oxidase has a high degree of sequence identity to previously characterized germin-like oxalate oxidases. two cdnas were isolated, phvoxoa, which ...	1998	9576772
fructose and mannose metabolism in aeromonas hydrophila: identification of transport systems and catabolic pathways.	aeromonas hydrophila was examined for fructose and mannose transport systems. a. hydrophila was shown to possess a phosphoenolpyruvate (pep): fructose phosphotransferase system (fructose-pts) and a mannose-specific pts, both induced by fructose and mannose. the mannose-pts of a. hydrophila exhibited cross-reactivity with escherichia coli mannose-pts proteins. the fructose-pts proteins exhibited cross-reactivities with e. coli and xanthomonas campestris fructose-pts proteins. in a. hydrophila gro ...	1998	9579084
a tn7-like transposon is present in the glmus region of the obligately chemoautolithotrophic bacterium thiobacillus ferrooxidans.	the region downstream of the thiobacillus ferrooxidans atcc 33020 atp operon was examined, and the genes encoding n-acetylglucosamine-1-uridyltransferase (glmu) and glucosamine synthetase (glms) were found. this atpefhagdc-glmus gene order is identical to that of escherichia coli. the t. ferrooxidans glms gene was shown to complement e. coli glms mutants for growth on minimal medium lacking glucosamine. a tn7-like transposon, tn5468, was found inserted into the region immediately downstream of t ...	1998	9603897
xanthomonas campestris pv. campestris requires a functional pigb for epiphytic survival and host infection.	when cauliflower plants (brassica oleraceae) were misted with bacterial suspensions of xanthomonas campestris pv. campestris (causal agent of black rot of cruciferous plants), two separate populations of the pathogen were associated with the leaves. initially, bacteria removable by sonication and sensitive to sodium hypochlorite treatment predominated (easily removable epiphytic bacteria, ereb). however, after 2 weeks, bacteria not removable by sonication and insensitive to sodium hypochlorite t ...	1998	9612945
entry of xanthomonas campestris pv. campestris into hydathodes of arabidopsis thaliana leaves: a system for studying early infection events in bacterial pathogenesis.	xanthomonas campestris pv. campestris (xcc) is a vascular pathogen of cruciferous plants that normally gains entry to plants via hydathodes. in order to study the basis of the preference for this protal of entry we have developed an arabidopsis thaliana model with attached or detached leaves partially immersed in a bacterial suspension. entry of bacteria into leaves, assessed by resistance to surface sterilization, could be detected after 1 h. dissection of leaves and histochemical staining for ...	1998	9612952
type iii protein secretion systems in bacterial pathogens of animals and plants.	various gram-negative animal and plant pathogens use a novel, sec-independent protein secretion system as a basic virulence mechanism. it is becoming increasingly clear that these so-called type iii secretion systems inject (translocate) proteins into the cytosol of eukaryotic cells, where the translocated proteins facilitate bacterial pathogenesis by specifically interfering with host cell signal transduction and other cellular processes. accordingly, some type iii secretion systems are activat ...	1998	9618447
structure of an extracellular mannosylated cellulose produced by a mutant strain of xanthomonas campestris.	structural studies were performed in two atypical polysaccharides, ps-1 and ps-2 isolated from the broth of a tn5 mutant strain of xanthomonas campestris. sugar composition, methylation and nuclear magnetic resonance analyses were determined. ps-1 is composed by repeating trisaccharide units containing d-glucose, d-mannose and having the structure. carbohydrate sequence [see text]. preliminary studies on the ps-2 show a polymer composed in a large extent of rhamnose. unexpectedly, this polysacch ...	1998	9620440
gene-for-gene disease resistance without the hypersensitive response in arabidopsis dnd1 mutant.	the cell death response known as the hypersensitive response (hr) is a central feature of gene-for-gene plant disease resistance. a mutant line of arabidopsis thaliana was identified in which effective gene-for-gene resistance occurs despite the virtual absence of hr cell death. plants mutated at the dnd1 locus are defective in hr cell death but retain characteristic responses to avirulent pseudomonas syringae such as induction of pathogenesis-related gene expression and strong restriction of pa ...	1998	9636234
insertion mutagenesis of xpsd, an outer-membrane protein involved in extracellular protein secretion in xanthomonas campestris pv. campestris.	xpsd is an outer-membrane protein required for extracellular protein secretion in xanthomonas campestris pv. campestris. cross-linking and gelfiltration chromatography analyses have suggested that it forms a multimer. to determine its structure-function relationship, linker-insertion mutants were constructed in an xpsd gene carried on a plasmid. to assay for secretion function, each mutant gene was introduced into an xpsd::tn5 mutant strain (xc1708) and assayed for alpha-amylase secretion on sta ...	1998	9639918
evidence for a role for the gumb and gumc gene products in the formation of xanthan from its pentasaccharide repeating unit by xanthomonas campestris.	the biosynthesis of the extracellular polysaccharide xanthan in xanthomonas campestris pv. campestris is directed by a cluster of 12 genes, gumb-gumm. several xanthan-deficient mutants of the wild-type strain 8004 have previously been described which carry tn5 insertions in this region of the chromosome. here it is shown that the transposon insertion in one of these mutants, strain 8397, is located 15 bp upstream of the translational start site of the gumb gene. edta-treated cells of strain 8397 ...	1998	9639919
macromolecular assembly and secretion across the bacterial cell envelope: type ii protein secretion systems.	a decade ago, pugsley and colleagues reported the existence of a large region of klebsiella dna, distinct from the klebsiella gene encoding pullulanase, which was necessary for secretion of this enzyme to the cell surface in escherichia coli (d'enfert et al., 1987a,b). the pul genes it contained proved to be the tip of an iceberg. the sequences reported before 1992 (d'enfert et al., 1987a,b; d'enfert & pugsley, 1989; pugsley & reyss, 1990; reyss & pugsley, 1990) included only one gene (puld) tha ...	1998	9641973
mutagenesis of the glucose-1-phosphate-binding site of potato tuber adp-glucose pyrophosphorylase	lysine (lys)-195 in the homotetrameric adp-glucose pyrophosphorylase (adpglc ppase) from escherichia coli was shown previously to be involved in the binding of the substrate glucose-1-phosphate (glc-1-p). this residue is highly conserved in the adpglc ppase family. site-directed mutagenesis was used to investigate the function of this conserved lys residue in the large and small subunits of the heterotetrameric potato (solanum tuberosum) tuber enzyme. the apparent affinity for glc-1-p of the wil ...	1998	9662541
the resolvase encoded by xanthomonas campestris transposable element isxc5 constitutes a new subfamily closely related to dna invertases.	conservative site-specific recombination is responsible for the resolution of cointegrates which result during the transposition of class ii transposable elements. resolution is catalysed by a transposon-encoded recombinase, resolvase, that belongs to a large family of recombinases, including dna invertases. resolvases and the related invertases are likely to employ similar reaction mechanisms during recombination. there are important differences, however. resolvases require two accessory dna bi ...	1998	9663657
the rpfa gene of xanthomonas campestris pathovar campestris, which is involved in the regulation of pathogenicity factor production, encodes an aconitase.	xanthomonas campestris pv campestris (xcc) is a plant pathogenic bacterium that controls the production of pathogenicity factors in part by a cluster of genes designated rpf (regulation of pathogenicity factors). sequence analysis of one of these genes (rpfa) revealed an open reading frame with amino acid sequence similarity to aconitases from other bacteria. aconitase activity was lower in cellular extracts of an rpfa::tn5 mutant than in those from the wild type. a zymogram of aconitase activit ...	1998	9663682
successful search for a resistance gene in tomato targeted against a virulence factor of a fungal pathogen.	the interaction between tomato and its fungal pathogen cladosporium fulvum complies with the gene-for-gene system, in which specific recognition of fungal proteins by plant genotypes with matching resistance genes results in host resistance. two proteins, ecp1 and ecp2, secreted by c. fulvum during infection, are required for full virulence of the fungus on tomato. we chose the most important virulence factor, ecp2, for a targeted search for hypersensitive response (hr)-based resistance among a ...	1998	9671796
construction and physiological analysis of a xanthomonas mutant to examine the role of the oxyr gene in oxidant-induced protection against peroxide killing.	we constructed and characterized a xanthomonas campestris pv. phaseoli oxyr mutant. the mutant was hypersensitive to h2o2 and menadione killing and had reduced aerobic plating efficiency. the oxidants' induction of the catalase and ahpc genes was also abolished in the mutant. analysis of the adaptive responses showed that hydrogen peroxide-induced protection against hydrogen peroxide was lost, while menadione-induced protection against hydrogen peroxide was retained in the oxyr mutant. these res ...	1998	9683499
gene transfer by transduction in the marine environment.	to determine the potential for bacteriophage-mediated gene transfer in the marine environment, we established transduction systems by using marine phage host isolates. plasmid pqsr50, which contains transposon tn5 and encodes kanamycin and streptomycin resistance, was used in plasmid transduction assays. both marine bacterial isolates and concentrated natural bacterial communities were used as recipients in transduction studies. transductants were detected by a gene probe complementary to the ne ...	1998	9687430
atzc is a new member of the amidohydrolase protein superfamily and is homologous to other atrazine-metabolizing enzymes.	pseudomonas sp. strain adp metabolizes atrazine to cyanuric acid via three plasmid-encoded enzymes, atza, atzb, and atzc. the first enzyme, atza, catalyzes the hydrolytic dechlorination of atrazine, yielding hydroxyatrazine. the second enzyme, atzb, catalyzes hydroxyatrazine deamidation, yielding n-isopropylammelide. in this study, the third gene in the atrazine catabolic pathway, atzc, was cloned from a pseudomonas sp. strain adp cosmid library as a 25-kb ecori dna fragment in escherichia coli. ...	1998	9422605
complementation analysis of the dichelobacter nodosus fimn, fimo, and fimp genes in pseudomonas aeruginosa and transcriptional analysis of the fimnop gene region.	the causative agent of ovine footrot, the gram-negative anaerobe dichelobacter nodosus, produces polar type iv fimbriae, which are the major protective antigens. the d. nodosus genes fimn, fimo, and fimp are homologs of the pseudomonas aeruginosa fimbrial assembly genes, pilb, pilc, and pild, respectively. both the pild and fimp genes encode prepilin peptidases that are responsible for cleavage of the leader sequence from the immature fimbrial subunit. to investigate the functional similarity of ...	1998	9423871
structure of proline iminopeptidase from xanthomonas campestris pv. citri: a prototype for the prolyl oligopeptidase family.	the proline iminopeptidase from xanthomonas campestris pv. citri is a serine peptidase that catalyses the removal of n-terminal proline residues from peptides with high specificity. we have solved its three-dimensional structure by multiple isomorphous replacement and refined it to a crystallographic r-factor of 19.2% using x-ray data to 2.7 a resolution. the protein is folded into two contiguous domains. the larger domain shows the general topology of the alpha/beta hydrolase fold, with a centr ...	1998	9427736
purification and expression of the gene iii protein from filamentous phage phi lf.	the gene iii protein (piii) from phi lf, a filamentous phage of xanthomonas campestris pv.campestris, was purified by gel filtration with fplc. the giii coding region was amplified by pcr, which was then cloned into puc18 and expressed in escherichia coli. the size of both piii, purified from phage particle and expressed in e. coli, is similar to the value deduced from the nucleotide sequence as shown by western blot analysis. this is different from the case in ff phages (f1, fd, and m13), in wh ...	1998	9439620
specific amino acid substitutions in the proline-rich motif of the rhizobium meliloti exop protein result in enhanced production of low-molecular-weight succinoglycan at the expense of high-molecular-weight succinoglycan.	the production of the acidic exopolysaccharide succinoglycan (eps i) by rhizobium meliloti exop* mutants expressing an exop protein lacking its c-terminal cytoplasmic domain and by mutants characterized by specific amino acid substitutions in the proline-rich motif (rx4px2px4spkx9ixgxmxgxg) located from positions 443 to 476 of the exop protein was analyzed. the absence of the c-terminal cytoplasmic exop domain (positions 484 to 786) and the substitution of both arginine443 by isoleucine443 and p ...	1998	9440529
homology and functional similarity of an hrp-linked pathogenicity locus, dspef, of erwinia amylovora and the avirulence locus avre of pseudomonas syringae pathovar tomato.	the "disease-specific" (dsp) region next to the hrp gene cluster of erwinia amylovora is required for pathogenicity but not for elicitation of the hypersensitive reaction. a 6.6-kb apparent operon, dspef, was found responsible for this phenotype. the operon contains genes dspe and dspf and is positively regulated by hrpl. a blast search revealed similarity in the dspe gene to a partial sequence of the avre locus of pseudomonas syringae pathovar tomato. the entire avre locus was sequenced. homolo ...	1998	9448330
[cloning of dna sequences involved in exopolysaccharide synthesis of xanthomonas campestris pv. campestris].	by using a cloned dna segment containing the mutated sequences from the exopolysaccharide-deficient mutant t117 of xanthomonas campestris pv. campestris as a probe, a 9.4 kb hindiii fragment harbouring dna sequences corresponding to the mutated site was identified and cloned from the wild-type strain. the fragment could complement the mutant strain t117 in trans and restore the synthesis of exopolysaccharide. this indicates that the fragment contains at least an intact gene which is involved in ...	1998	12549411
diversity among xanthomonads pathogenic on pepper and tomato.	xanthomonas campestris pv. vesicatoria, causal agent of bacterial spot of tomato and pepper, had been considered for nearly 70 years to be a relatively homogeneous organism. however, in the past decade this bacterium was determined to be composed of two genetically and phenotypically distinct groups. the two groups, designated a and b, were distinguished based on amylolytic activity, expression of unique protein bands, reaction on differential hosts (tomato races t1 and t2), reaction patterns wi ...	1998	15012492
identification of hydrocarbon-degrading bacteria in soil by reverse sample genome probing.	bacteria with limited genomic cross-hybridization were isolated from soil contaminated with c5+, a mixture of hydrocarbons, and identified by partial 16s rrna sequencing. filters containing denatured genomic dnas were used in a reverse sample genome probe (rsgp) procedure for analysis of the effect of an easily degradable compound (toluene) and a highly recalcitrant compound (dicyclopentadiene [dcpd]) on community composition. hybridization with labeled total-community dna isolated from soil exp ...	1998	16349504
enhancement of exopolysaccharide production by lactobacillus delbrueckii subsp. bulgaricus ncfb 2772 with a simplified defined medium.	the aim of this work was to investigate the medium requirements for growth and production of exopolysaccharides by lactobacillus delbrueckii subsp. bulgaricus ncfb 2772. the strain was grown in batch cultures on a chemically defined medium, and the technique of single omission of medium components was applied to determine the nutritional requirements. the omission of aspartic acid, glutamic acid, or glycine affected growth only slightly, and the omission of glutamine, asparagine, or threonine re ...	1998	16349540
the molecular genetics of virulence of xanthomonas campestris.	bacteria belonging to the genus xanthomonas are important pathogens of many plants, and their virulence appears to be due primarily to secreted and surface compounds that could increase host nutrient loss, or avoid or suppress unfavorable conditions in the host. type ii and iii secretory pathways are essential for virulence. some individual extracellular enzymes (type ii-secretion dependent) affect final bacterial population levels, whereas some avirulence gene products (type iii-secretion depen ...	1999	14538126
xanthan gum production by xanthomonas campestris w.t. fermentation from chestnut extract.	xanthomonas campestris w.t. was used for production of xanthan gum in fermentations with chestnut flour for the first time. fermentations were carried out with either chestnut flour or its soluble sugars (33.5%) and starch (53.6%), respectively, at 28 degrees c and 200 rpm at initial ph 7.0 in flasks. the effect of agitation rate (at 200, 400, and 600 rpm) on xanthan gum production was also studied in a 2-l batch reactor. it was found that xanthan production reaches a maximum value of 3.3 g/100 ...	1999	15304770
effect of citric acid on the biosynthesis and composition of xanthan.	the effect of citric acid metabolism by xanthomonas campestris on composition of xanthan has been studied. citric acid consumption in fed-batch and continuous fermentation increased the pyruvic acid content of xanthan. an increase in pyruvic acid content in xanthan has been explained with the help of energy balance in xanthan biosynthesis.	1999	12501381
location and survival of leaf-associated bacteria in relation to pathogenicity and potential for growth within the leaf	the growth and survival of pathogenic and nonpathogenic pseudomonas syringae strains and of the nonpathogenic species pantoea agglomerans, stenotrophomonas maltophilia, and methylobacterium organophilum were compared in the phyllosphere of bean. in general, the plant pathogens survived better than the nonpathogens on leaves under environmental stress. the sizes of the total leaf-associated populations of the pathogenic p. syringae strains were greater than the sizes of the total leaf-associated ...	1999	10103233
cuma, a gene encoding a multicopper oxidase, is involved in mn2+ oxidation in pseudomonas putida gb-1.	pseudomonas putida gb-1-002 catalyzes the oxidation of mn2+. nucleotide sequence analysis of the transposon insertion site of a nonoxidizing mutant revealed a gene (designated cuma) encoding a protein homologous to multicopper oxidases. addition of cu2+ increased the mn2+-oxidizing activity of the p. putida wild type by a factor of approximately 5. the growth rates of the wild type and the mutant were not affected by added cu2+. a second open reading frame (designated cumb) is located downstream ...	1999	10103278
transcription of the genome of the filamentous bacteriophage cf from both plus and minus dna strands.	the filamentous bacteriophage cf infects the bacterium xanthomonas campestris pv. citri. northern blot analysis with probes derived from various restriction fragments of cf replicative form (rf) dna has revealed the presence of five major phage-specific transcripts in infected cells. four of these transcripts were shown to be derived from the region of the cf genome extending from gene ii to gene viii and are consistent with the cascade model of transcription proposed for ff coliphages. these tr ...	1999	10191188
azospirillum irakense produces a novel type of pectate lyase.	the pela gene from the n2-fixing plant-associated bacterium azospirillum irakense, encoding a pectate lyase, was isolated by heterologous expression in escherichia coli. nucleotide sequence analysis of the region containing pela indicated an open reading frame of 1,296 bp, coding for a preprotein of 432 amino acids with a typical amino-terminal signal peptide of 24 amino acids. n-terminal amino acid sequencing confirmed the processing of the protein in e. coli at the signal peptidase cleavage si ...	1999	10198006
the adsorption protein genes of xanthomonas campestris filamentous phages determining host specificity.	gene iii (giii) of philf, a filamentous phage specifically infecting xanthomonas campestris pv. campestris, was previously shown to encode a virion-associated protein (piii) required for phage adsorption. in this study, the transcription start site for the gene and the n-terminal sequence of the protein were determined, resulting in the revision of the translation initiation site from the one previously predicted for this gene. for comparative study, the giii of phixv, a filamentous phage specif ...	1999	10198010
characterization of two novel type i ribosome-inactivating proteins from the storage roots of the andean crop mirabilis expansa.	two novel type i ribosome-inactivating proteins (rips) were found in the storage roots of mirabilis expansa, an underutilized andean root crop. the two rips, named me1 and me2, were purified to homogeneity by ammonium sulfate precipitation, cation-exchange perfusion chromatography, and c4 reverse-phase chromatography. the two proteins were found to be similar in size (27 and 27.5 kd) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their isoelectric points were determined to be ...	1999	10198104
genetic diversity of african and worldwide strains of ralstonia solanacearum as determined by pcr-restriction fragment length polymorphism analysis of the hrp gene region	the genetic diversity among a worldwide collection of 120 strains of ralstonia solanacearum was assessed by restriction fragment length polymorphism (rflp) analysis of amplified fragments from the hrp gene region. five amplified fragments appeared to be specific to r. solanacearum. fifteen different profiles were identified among the 120 bacterial strains, and a hierarchical cluster analysis distributed them into eight clusters. each cluster included strains belonging to a single biovar, except ...	1999	10224018
molecular characterization of a flagellar export locus of helicobacter pylori.	motility of helicobacter species has been shown to be essential for successful colonization of the host. we have investigated the organization of a flagellar export locus in helicobacter pylori. a 7-kb fragment of the h. pylori ccug 17874 genome was cloned and sequenced, revealing an operon comprising an open reading frame of unknown function (orf03), essential housekeeping genes (iles and murb), flagellar export genes (flii and fliq), and a homolog to a gene implicated in virulence factor trans ...	1999	10225855
direct interaction of the epsl and epsm proteins of the general secretion apparatus in vibrio cholerae.	the general secretion pathway of gram-negative bacteria is responsible for extracellular secretion of a number of different proteins, including proteases and toxins. this pathway supports secretion of proteins across the cell envelope in two distinct steps, in which the second step, involving translocation through the outer membrane, is assisted by at least 13 different gene products. two of these components, the cytoplasmic membrane proteins epsl and epsm of vibrio cholerae, have been purified ...	1999	10322014
molecular characterization of a brucella species large dna fragment deleted in brucella abortus strains: evidence for a locus involved in the synthesis of a polysaccharide.	a brucella melitensis 16m dna fragment of 17,119 bp, which contains a large region deleted in b. abortus strains and dna flanking one side of the deletion, has been characterized. in addition to the previously identified omp31 gene, 14 hypothetical genes have been identified in the b. melitensis fragment, most of them showing homology to genes involved in the synthesis of a polysaccharide. considering that 10 of the 15 genes are missing in b. abortus and that all the polysaccharides described in ...	1999	10338472
quantitative immunofluorescence of regulated eps gene expression in single cells of ralstonia solanacearum.	ralstonia solanacearum, a phytopathogenic bacterium, uses an environmentally sensitive and complex regulatory network to control expression of multiple virulence genes. part of this network is an unusual autoregulatory system that produces and senses 3-hydroxypalmitic acid methyl ester. in culture, this autoregulatory system ensures that expression of virulence genes, such as those of the eps operon encoding biosynthesis of the acidic extracellular polysaccharide, occurs only at high cell densit ...	1999	10347013
a pyruvated mannose-specific xanthan lyase involved in xanthan degradation by paenibacillus alginolyticus xl-1.	the xanthan-degrading bacterium paenibacillus alginolyticus xl-1, isolated from soil, degrades approximately 28% of the xanthan molecule and appears to leave the backbone intact. several xanthan-degrading enzymes were excreted during growth on xanthan, including xanthan lyase. xanthan lyase production was induced by xanthan and inhibited by glucose and low-molecular-weight enzymatic degradation products from xanthan. a xanthan lyase with a molecular mass of 85 kda and a pi of 7.9 was purified an ...	1999	10347025
structures and properties of gellan polymers produced by sphingomonas paucimobilis atcc 31461 from lactose compared with those produced from glucose and from cheese whey	the dairy industry produces large quantities of whey as a by-product of cheese production and is increasingly looking for new ways to utilize this waste product. gellan gum is reliably produced by sphingomonas paucimobilis in growth media containing lactose, a significant component of cheese whey, as a carbon source. we studied and compared polysaccharide biosynthesis by s. paucimobilis atcc 31461 in media containing glucose, lactose (5 to 30 g/liter), and sweet cheese whey. we found that alteri ...	1999	10347031
microbial system for polysaccharide depolymerization: enzymatic route for xanthan depolymerization by bacillus sp. strain gl1.	an enzymatic route for the depolymerization of a heteropolysaccharide (xanthan) in bacillus sp. strain gl1, which was closely related to brevibacillus thermoruber, was determined by analyzing the structures of xanthan depolymerization products. the bacterium produces extracellular xanthan lyase catalyzing the cleavage of the glycosidic bond between pyruvylated mannosyl and glucuronyl residues in xanthan side chains (w. hashimoto et al., appl. environ. microbiol. 64:3765-3768, 1998). the modified ...	1999	10347037
effect of the nitrogen source on pyruvate content and rheological properties of xanthan	batch and fed batch cultivations of xanthomonas campestris with varying amounts of the n source (nh4cl) yield xanthan polymers which differ in pyruvate content. analyzing the rheological properties of the xanthans produced exhibits that it is not only the molecular mass but also the pyruvate content that affects the viscosity of xanthan solutions. however, there is obviously no simple functional dependency but rather a step increase in viscosity when going from below 2 to above 3 wt % of pyruvat ...	1999	10356261
pseudomonas syringae phytotoxins: mode of action, regulation, and biosynthesis by peptide and polyketide synthetases.	coronatine, syringomycin, syringopeptin, tabtoxin, and phaseolotoxin are the most intensively studied phytotoxins of pseudomonas syringae, and each contributes significantly to bacterial virulence in plants. coronatine functions partly as a mimic of methyl jasmonate, a hormone synthesized by plants undergoing biological stress. syringomycin and syringopeptin form pores in plasma membranes, a process that leads to electrolyte leakage. tabtoxin and phaseolotoxin are strongly antimicrobial and func ...	1999	10357851
genome size and macrorestriction map of xanthomonas campestris pv. glycines yr32 chromosome.	xanthomonas campestris is an important plant pathogenic bacterium which causes severe diseases in a wide variety of plant species. we have generated a macrorestriction map of the x. campestris (axonopodis) pv. glycines chromosome employing pulsed-field gel electrophoresis (pfge). restriction endonucleases paci (5'-ttaattaa), pmei (5'-gtttaaac) and swai (5'-atttaaat) digested the chromosomal dna into three, five, and five fragments, respectively. in addition, intron-encoded restriction endonuclea ...	1999	10361709
enhanced expression and activation of the alternative oxidase during infection of arabidopsis with pseudomonas syringae pv tomato.	cyanide-resistant ("alternative") respiration was studied in arabidopsis during incompatible and compatible infection with pseudomonas syringae pv tomato dc3000. total leaf respiration increased as the leaves became necrotic, as did the cyanide-resistant component that was sensitive to salicylhydroxamic acid. infiltration of leaves with an avirulent strain rapidly induced alternative oxidase (aox) mrna, whereas the increase was delayed in the compatible combination. the increase in mrna correlat ...	1999	10364404
the mdoc gene of escherichia coli encodes a membrane protein that is required for succinylation of osmoregulated periplasmic glucans.	osmoregulated periplasmic glucans (opgs) of escherichia coli are anionic oligosaccharides that accumulate in the periplasmic space in response to low osmolarity of the medium. their anionic character is provided by the substitution of the glucosidic backbone by phosphoglycerol originating from the membrane phospholipids and by succinyl residues from unknown origin. a phosphoglycerol-transferase-deficient mdob mutant was subjected to tn5 transposon mutagenesis, and putative mutant clones were scr ...	1999	10368134
[microbiological synthesis of virazole by immobilized cells].	based on the isotherms of adsorption of the cells of xanthomonas campestris b-610 to glass and polyvinyl fibers, immobilized systems were produced, in which the cell content was sufficient for enzymatic synthesis of virazole (1-[beta-d-ribofuranosyl]-1,2,4-triazole-3-carboxamide) using adenosine as a donor of ribose (50-60% conversion of 1,2,4-triazole-3-carboxamide). the immobilized cells thus obtained retain their enzymatic activity for six months and can be used repeatedly.	1999	10368847
ribonucleotide reduction in pseudomonas species: simultaneous presence of active enzymes from different classes.	three separate classes of ribonucleotide reductases exist in nature. they differ widely in protein structure. class i enzymes are found in aerobic bacteria and eukaryotes; class ii enzymes are found in aerobic and anaerobic bacteria; class iii enzymes are found in strict and facultative anaerobic bacteria. usually, but not always, one organism contains only one or two (in facultative anaerobes) classes. surprisingly, the genomic sequence of pseudomonas aeruginosa contains sequences for each of t ...	1999	10383965
structure-function analysis of xcpp, a component involved in general secretory pathway-dependent protein secretion in pseudomonas aeruginosa.	the general secretory pathway of pseudomonas aeruginosa is required for the transport of signal peptide-containing exoproteins across the cell envelope. after completion of the sec-dependent translocation of exoproteins across the inner membrane and cleavage of the signal peptide, the xcp machinery mediates translocation across the outer membrane. this machinery consists of 12 components, of which xcpq (gspd) is the sole outer membrane protein. xcpq forms a multimeric ring-shaped structure, with ...	1999	10383969
molecular cloning and characterization of a locus responsible for o acetylation of the o polysaccharide of legionella pneumophila serogroup 1 lipopolysaccharide.	complementation experiments, tn5 mutagenesis, and dna sequencing were used to identify a locus (lag-1) that participates in acetylation of legionella pneumophila serogroup 1 lipopolysaccharide. nuclear magnetic resonance analyses of lipopolysaccharides from mutant and complemented strains suggest that lag-1 is responsible for o acetylation of serogroup 1 o polysaccharide.	1999	10383989
determination of total protein content of bacterial cells by sypro staining and flow cytometry.	an assay has been developed for measuring protein biomass of marine planktonic bacteria by flow cytometry. the method was calibrated by using five species of bacteria (an arcobacter sp., a cytophaga sp., an oceanospirillum sp., a pseudoalteromonas sp., and a vibrio sp.) recently isolated from seawater samples and grown in culture at different temperatures. the intensity of sypro-protein fluorescence of these bacteria strongly correlated with their total protein content, measured by the bicinchon ...	1999	10388732
identification of a novel beta-lactamase produced by xanthomonas campestris, a phytopathogenic bacterium.	the xanthomonas campestris pv. campestris 11 chromosome encodes a periplasmic beta-lactamase of 30 kda. gene replacement and complementation confirmed the presence of this enzyme. its deduced amino acid sequence shows identity and conserved domains between it and stenotrophomonas maltophilia l2 and other ambler class a/bush group 2 beta-lactamases. southern hybridization detected a single homologous fragment in each of 12 other xanthomonas strains, indicating that the presence of a beta-lactamas ...	1999	10390247
characterization of is1389, a new member of the is3 family of insertion sequences isolated from xanthomonas campestris pv. amaranthicola.	is1389, a new insertion sequence belonging to the is3 family, has been identified in xanthomonas campestris pv. amaranthicola. the genome of this bacterium contains at least 11 copies of the element, whereas no hybridizing sequences were detected in other xanthomonas species [x. axonopodis, x. fragaridae, x. phaseoli, and x. (stenotrophomonas) maltophila]. two nearly identical copies of the element (is1389-a and is1389-b) were characterized. according to analysis of sequence alignments and simil ...	1999	10398747
specific detection of xylella fastidiosa pierce's disease strains.	pierce's disease (pd, xylella fastidiosa) of grapevine is the primary pathogen limiting vinifera grape production in florida and other regions of the southeastern united states. quick and accurate detection of pd strains is essential for pd studies and control. a unique random amplified polymorphic dna (pd1-1-2) was isolated from a pd strain from florida. fragment pd1-1-2 was cloned, sequenced, and found to be 1005 bp in length. pcr primers were designed to utilize these sequence data for pd str ...	1999	10398832
the genes ruba and rubb for alkane degradation in acinetobacter sp. strain adp1 are in an operon with estb, encoding an esterase, and oxyr.	alkanes are oxidized in acinetobacter sp. strain adp1 by a three-component alkane monooxygenase, composed of alkane hydroxylase, rubredoxin, and rubredoxin reductase. ruba and rubb encode rubredoxin and a nad(p)h-dependent rubredoxin reductase. we demonstrate here that single base pair substitutions in ruba or rubb lead to defects in alkane degradation, showing that both genes are essential for alkane utilization. differences in the degradation capacity for hexadecane and dodecane in these mutan ...	1999	10400587
identification of the promoter region of the xanthomonas campestris pv. citri reca gene responsible for induction by dna-damaging agents.	the abundance of the reca protein and of reca transcripts was markedly increased on exposure of xanthomonas campestris pathovar citri to various dna-damaging agents, including mitomycin c. the promoter sequence responsible for mediating the sensitivity of reca expression to dna damage was investigated by subcloning a 426-bp restriction fragment of the 5' untranslated and coding region of the gene into a promoterless vector containing the luxab genes of vibrio fischeri. xanthomonas campestris pv. ...	1999	10418131
influence of soft rot bacteria on growth of listeria monocytogenes on potato tuber slices.	growth of listeria monocytogenes on potato tuber slices and its interaction with four representative species of soft rot bacteria (pseudomonas fluorescens, p. viridiflava, erwinia carotovora subsp. carotovora, and xanthomonas campestris) were investigated. when potato tuber slices were inoculated with one of two l. monocytogenes strains (scott a and atcc 15313), an increase in numbers of 3 to 4 logs per gram of tissue was observed with samples that were stored at 20 degrees c for 6 days. however ...	1999	10419206
community analysis of biofilters using fluorescence in situ hybridization including a new probe for the xanthomonas branch of the class proteobacteria.	domain-, class-, and subclass-specific rrna-targeted probes were applied to investigate the microbial communities of three industrial and three laboratory-scale biofilters. the set of probes also included a new probe (named xan818) specific for the xanthomonas branch of the class proteobacteria; this probe is described in this study. the members of the xanthomonas branch do not hybridize with previously developed rrna-targeted oligonucleotide probes for the alpha-, beta-, and gamma-proteobacteri ...	1999	10427047
a high-density physical map of sinorhizobium meliloti 1021 chromosome derived from bacterial artificial chromosome library.	as part of the european sinorhizobium meliloti (strain 1021) chromosome sequencing project, four genomic bacterial artificial chromosome (bac) libraries have been constructed, one of which was mainly used for chromosome mapping. this library consists of 1,824 clones with an average insert size of 80 kilobases and represents approximately 20-fold total genome coverage [6.8 megabases (mbs)]. pcr screening of 384 bac clones with 447 chromosomal markers (pcr primer pairs), consisting of 73 markers r ...	1999	10430947
the xanthomonas hrp type iii system secretes proteins from plant and mammalian bacterial pathogens.	studies of essential pathogenicity determinants in gram-negative bacteria have revealed the conservation of type iii protein secretion systems that allow delivery of virulence factors into host cells from plant and animal pathogens. ten of 21 hrp proteins of the plant pathogen xanthomonas campestris pv. vesicatoria have been suggested to be part of a type iii machinery. here, we report the hrp-dependent secretion of two avirulence proteins, avrbs3 and avrrxv, by x. campestris pv. vesicatoria str ...	1999	10430949
role of the hrp type iii protein secretion system in growth of pseudomonas syringae pv. syringae b728a on host plants in the field.	hrp genes are reportedly required for pathogenicity in pseudomonas syringae pv. syringae (pss) and other phytopathogenic bacterial species. a subset of these genes encodes a type iii secretion system through which virulence factors are thought to be delivered to plant cells. in this study, we sought to better understand the role that hrp genes play in interactions of pss with its host as they occur naturally under field conditions. population sizes of hrp mutants with defects in genes that encod ...	1999	10449783
a simplified subtractive hybridization protocol used to isolate dna sequences specific to xylella fastidiosa.	a simplified protocol of subtractive hybridization based on the technique of l. m. kunkel, a. p. monaco, w. middlesworth, h. d. ochs & s. a. latt (1985, proc natl acad sci usa, 82, 4778-4782) was used to obtain dna sequences specific to xylella fastidiosa isolated from diseased citrus plants. as a driver, dna extracted from bacteria showing different degrees of relatedness was used: xy. fastidiosa 788 isolated from another host (plum), xanthomonas campestris pv. campestris and burkholderia gladi ...	1999	10463163
the 17-gene ethanolamine (eut) operon of salmonella typhimurium encodes five homologues of carboxysome shell proteins.	the eut operon of salmonella typhimurium encodes proteins involved in the cobalamin-dependent degradation of ethanolamine. previous genetic analysis revealed six eut genes that are needed for aerobic use of ethanolamine; one (eutr), encodes a positive regulator which mediates induction of the operon by vitamin b12 plus ethanolamine. the dna sequence of the eut operon included 17 genes, suggesting a more complex pathway than that revealed genetically. we have correlated an open reading frame in t ...	1999	10464203
characterization of transposon-generated protease mutant of xanthomonas campestris pathovar glycine 8ra. enzyme activity, cloning, and mapping of flanking dna.	protease negative mutant of xanthomonas campestris pathovar glycine 8ra (prt-mutant) was constructed by mutagenesis employing artificial transposon omegon-km. transposon delivery was conducted through diparental conjugation using x. campestris pathovar glycine 8ra as recipient and escherichia coli s17-1 carrying pjff 3500 plasmid as the donor. the frequency of transconjugation was found 1.9 x 10(-7) per recipient. enzyme analysis indicated the presence of mutant with lower protease activity than ...	1999	10464767
bacillus subtilis aconitase is an rna-binding protein.	the aconitase protein of bacillus subtilis was able to bind specifically to sequences resembling the iron response elements (ires) found in eukaryotic mrnas. the sequences bound include the rabbit ferritin ire and ire-like sequences in the b. subtilis operons that encode the major cytochrome oxidase and an iron uptake system. ire binding activity was affected by the availability of iron both in vivo and in vitro. in eukaryotic cells, aconitase-like proteins regulate translation and stability of ...	1999	10468622
expression of the isoamylase gene of flavobacterium odoratum ku in escherichia coli and identification of essential residues of the enzyme by site-directed mutagenesis.	the isoamylase gene from flavobacterium odoratum ku was cloned into and expressed in escherichia coli jm109. the promoter of the gene was successful in e. coli, and the enzyme produced was excreted into the culture medium, depending on the amount of the enzyme expressed. the enzyme found in the culture medium showed almost the same m(r), heat-inactivating constant, and n-terminal sequence as those of the enzyme accumulated in the periplasmic space. this result indicated that the enzyme accumulat ...	1999	10473430
development and application of pathovar-specific monoclonal antibodies that recognize the lipopolysaccharide o antigen and the type iv fimbriae of xanthomonas hyacinthi.	the objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (mabs). mice were immunized with a crude cell wall preparation (shear fraction) from xanthomonas hyacinthi and with purified type iv fimbriae. hybridomas were screened for a positive reaction with x. hyacinthi cells or fimbriae and for a negative reaction with x. translucens pv. graminis or erwinia carotovora subsp. carotovora. nine mabs recognized fim ...	1999	10473431
an hrcu-homologous gene mutant of xanthomonas campestris pv. glycines 8ra that lost pathogenicity on the host plant but was able to elicit the hypersensitive response on nonhosts.	transposon mutagenesis was used to isolate nonpathogenic mutants of xanthomonas campestris pv. glycines 8ra, which causes bacterial pustule disease in soybean. a 6.1-kb dna region in which a mutation gave loss of pathogenicity was isolated and found to carry six open reading frames (orfs). four orfs had homology with hrcu, hrcv, hrcr, and hrcs genes of ralstonia solanacearum and x. campestris pv. vesicatoria. one nonpathogenic mutant, x. campestris pv. glycines h80, lost pathogenicity on soybean ...	1999	10478481
a transposon insertion in the gumg homologue of xanthomonas oryzae pv. oryzae causes loss of extracellular polysaccharide production and virulence.	xanthomonas oryzae pv. oryzae causes a serious disease of rice called bacterial leaf blight. it produces copious amounts of extracellular polysaccharide (eps). an eps- and virulence-deficient mutant of x. oryzae pv. oryzae was isolated by tn5 mutagenesis. the mutant allele in this strain was cloned by transposon tagging in the escherichia coli vector pbluescript and the dna sequences flanking the transposon insertion site were determined. computer-based similarity searches in the dna database us ...	1999	10481086
role of the alkyl hydroperoxide reductase (ahpcf) gene in oxidative stress defense of the obligate anaerobe bacteroides fragilis.	in this study we report the identification and role of the alkyl hydroperoxide reductase (ahp) gene in bacteroides fragilis. the two components of ahp, ahpc, and ahpf, are organized in an operon, and the deduced amino acid sequences revealed that b. fragilis ahpcf shares approximately 60% identity to orthologues in other gram-positive and gram-negative bacteria. northern blot hybridization analysis of total rna showed that the ahpcf genes were transcribed as a polycistronic 2.4-kb mrna and that ...	1999	10482511
identification of a pathogenicity island, which contains genes for virulence and avirulence, on a large native plasmid in the bean pathogen pseudomonas syringae pathovar phaseolicola.	the 154-kb plasmid was cured from race 7 strain 1449b of the phytopathogen pseudomonas syringae pv. phaseolicola (pph). cured strains lost virulence toward bean, causing the hypersensitive reaction in previously susceptible cultivars. restoration of virulence was achieved by complementation with cosmid clones spanning a 30-kb region of the plasmid that contained previously identified avirulence (avr) genes avrd, avrpphc, and avrpphf. single transposon insertions at multiple sites (including one ...	1999	10485919
a rolling-circle miniplasmid of xanthomonas campestris pv. glycines: the nucleotide sequence and its use as a cloning vector.	the indigenous multicopy miniplasmid (pxg33) of xanthomonas campestris pv. glycines was entirely sequenced and evaluated as a cloning vector for xanthomonas. the pxg33 contains 1738 bp and the nucleotide sequence revealed a consensus nicking site (tgata) described for the pc194 family of rolling-circle replicating (rcr) plasmids. this nicking site is embebbed in a region of high potential to form a number of stem-loop structures. the predicted protein (rep) showed conserved amino acid residues a ...	1999	10489329
genomic subtractive hybridization and selective capture of transcribed sequences identify a novel salmonella typhimurium fimbrial operon and putative transcriptional regulator that are absent from the salmonella typhi genome.	salmonella typhi, the etiologic agent of typhoid fever, is adapted to the human host and unable to infect nonprimate species. the genetic basis for host specificity in s. typhi is unknown. the avirulence of s. typhi in animal hosts may result from a lack of genes present in the broad-host-range pathogen salmonella typhimurium. genomic subtractive hybridization was successfully employed to isolate s. typhimurium genomic sequences which are absent from the s. typhi genome. these genomic subtracted ...	1999	10496884
functions of two types of nadh oxidases in energy metabolism and oxidative stress of streptococcus mutans.	we have previously identified two distinct nadh oxidases corresponding to h(2)o(2)-forming oxidase (nox-1) and h(2)o-forming oxidase (nox-2) induced in streptococcus mutans. sequence analyses indicated a strong similarity between nox-1 and ahpf, the flavoprotein component of salmonella typhimurium alkyl hydroperoxide reductase; an open reading frame upstream of nox-1 also showed homology to ahpc, the direct peroxide-reducing component of s. typhimurium alkyl hydroperoxide reductase. to determine ...	1999	10498705
the pila gene of xanthomonas campestris pv. citri is required for infection by the filamentous phage cf.	host factors that are important for infection of xanthomonas campestris pv. citri by the filamentous bacteriophage cf were investigated by transposon mutagenesis with tn5tac1. a mutant, xt501, that was resistant to cf infection was recovered, showing that the gene inactivated by the transposon is required for infection by the phage but not for cf replication or assembly. a 1.7-kb saci-apai dna fragment from xt501 containing the bacterial dna flanking one end of the transposon was cloned and show ...	1999	10503532
unraveling the function of glycosyltransferases in streptococcus thermophilus sfi6.	streptococcus thermophilus sfi6 produces a texturizing exopolysaccharide (eps) consisting of a -->3)[alpha-d-galp-(1-->6)]-beta-d-glcp-(1-->3)-alpha-d-galpnac-(1--> 3)-beta-d-galp-(1--> repeating unit. we previously identified and analyzed a 14.5-kb gene cluster from s. thermophilus sfi6 consisting of 13 genes responsible for its eps production. within this gene cluster, we found a central region of genes (epse, epsf, epsg, and epsi) that showed similarity to glycosyltransferases. in this study, ...	1999	10515925
identification of new early markers of the hypersensitive response in arabidopsis thaliana(1).	new molecular markers of the hypersensitive response (hr) of arabidopsis thaliana to the bacterial pathogen xanthomonas campestris pv. campestris (x.c.c.) have been identified by differential screening of a cdna library constructed from suspension cells inoculated by an hr-inducing strain in the presence of cycloheximide. seven families of genes (called athsr) have been isolated, show similarities to voltage-dependent anion channels (vdac) and alternative oxidases, or are novel proteins. athsr g ...	1999	10518009
the o-chain polysaccharide of the lipopolysaccharide of xanthomonas campestris pv. begoniae gspb 525 is a partially l-xylosylated l-rhamnan.	the o-chain polysaccharide (ops) of the lipopolysaccharide of xanthomonas campestris pv. begoniae gspb 525 was found to contain l-rhamnose and l-xylose in the ratio 1:0.6. the ops lacked strict regularity because of nonstoichiometric xylosylation of the main rhamnan chain. based on methylation analysis, smith degradation, and 1h and 13c nmr spectroscopy, including cosy, tocsy, noesy, and h-detected 1h,13c heteronuclear multiple-quantum coherence (hmqc) experiments, the following structure of the ...	1999	10520263
induction of the viable but non-culturable condition in xanthomonas campestris pv. campestris in liquid microcosms and sterile soil.	xanthomonas campestris pathovar campestris was examined for the ability to enter the viable but non-culturable (vbnc) state. when nutrients were removed from a bacterial culture, the culturability dropped to undetectable levels within 6 weeks while the concentration of viable cells remained above 10(5) cells ml(-1). addition of cupric sulfate facilitated this process. when bacteria were placed in autoclaved soil, culturability dropped by at least four logs within 5 days of the experiment while t ...	1999	10525176
molecular characterization of the locus encoding biosynthesis of the lipopolysaccharide o antigen of escherichia coli serotype o113.	shiga toxigenic escherichia coli (stec) strains are a diverse group of organisms capable of causing severe gastrointestinal disease in humans. within the stec family, eae-positive stec strains, particularly those belonging to serogroups o157 and o111, appear to have greater virulence for humans. however, in spite of being eae negative, stec strains belonging to serogroup o113 have frequently been associated with cases of severe stec disease, including hemolytic-uremic syndrome (hus). western blo ...	1999	10531250
identification of regions of the chromosome of neisseria meningitidis and neisseria gonorrhoeae which are specific to the pathogenic neisseria species.	neisseria meningitidis and neisseria gonorrhoeae give rise to dramatically different diseases. their interactions with the host, however, do share common characteristics: they are both human pathogens which do not survive in the environment and which colonize and invade mucosa at their port of entry. it is therefore likely that they have common properties that might not be found in nonpathogenic bacteria belonging to the same genetically related group, such as neisseria lactamica. their common p ...	1999	10531275
mutations in the regulatory gene hrpg of xanthomonas campestris pv. vesicatoria result in constitutive expression of all hrp genes.	hrpg is a key regulatory gene for transcriptional activation of pathogenicity genes (hrp) of xanthomonas campestris pv. vesicatoria. we identified three mutations in hrpg which render hrp gene expression constitutive in normally suppressing medium. the mutations in hrpg result in novel amino acid substitutions compared to mutations in related proteins, such as ompr. in addition, mutated hrpg enhances the timing and intensity of plant reactions in infection assays.	1999	10542187
isolation of polymyxin b-susceptible mutants of burkholderia pseudomallei and molecular characterization of genetic loci involved in polymyxin b resistance.	burkholderia pseudomallei is a gram-negative bacterium that causes the disease known as melioidosis. this pathogen is endemic to southeast asia and northern australia and is particularly problematic in northeastern thailand. it has been previously reported that b. pseudomallei is resistant to the killing action of cationic antimicrobial peptides, including human neutrophil peptide, protamine sulfate, poly-l-lysine, magainins, and polymyxins. recently, we have also found that the virulent clinica ...	1999	10543742
distribution of tetracycline resistance genes and transposons among phylloplane bacteria in michigan apple orchards.	the extent and nature of tetracycline resistance in bacterial populations of two apple orchards with no or a limited history of oxytetracycline usage were assessed. tetracycline-resistant (tc(r)) bacteria were mostly gram negative and represented from 0 to 47% of the total bacterial population on blossoms and leaves (versus 26 to 84% for streptomycin-resistant bacteria). a total of 87 isolates were screened for the presence of specific tc(r) determinants. tc(r) was determined to be due to the pr ...	1999	10543801
a physical map of the chromosome of xanthomonas campestris pv. phaseoli var. fuscans bxpf65.	a physical map of the xanthomonas campestris pv. phaseoli var. fuscans bxpf65 chromosome was constructed by pfge and southern hybridization. the chromosome was 3938 kb and was composed of 39 xbai restriction fragments. the size is close to that estimated for x. campestris pv. campestris based on dna renaturation kinetics. macrorestriction fragments containing genes for a 16s rrna, pectate lyase, two-component regulatory system and hrp cluster were located on the physical map. each of these probe ...	1999	10547448
characterization of a ferric uptake regulator (fur) gene from xanthomonas campestris pv. phaseoli with unusual primary structure, genome organization, and expression patterns.	a 1.5kb dna fragment from xanthomonas campestris pv. phaseoli containing fur was characterized. fur is a single copy gene that is transcribed as a monocistronic mrna. the predicted amino acid sequence of xp fur showed extensive identity to other fur proteins. however, xp fur has many distinct features, particularly a lack of cysteine residues in the conserved metal-binding motifs and unusual modifications in the carboxy-terminus region. the nucleotide sequences of fur genes from four other xanth ...	1999	10548726
purification and characterization of s-adenosyl-l-methionine: desoxyhemigossypol-6-o-methyltransferase from cotton plants. an enzyme capable of methylating the defense terpenoids of cotton.	cotton contains a unique group of terpenoids including desoxyhemigossypol, hemigossypol, gossypol, hemigossypolone, and the heliocides that are part of the plant's defense system against pathogenic fungi and insects. desoxyhemigossypol is a key intermediate in the biosynthesis of these compounds. we have isolated, purified, and characterized from cotton stele tissue infected with verticillium dahliae a methyltransferase (s-adenosyl-l-met: desoxyhemigossypol-6-o-methyltransferase) that specifical ...	1999	10557251
immunochemical characterization and taxonomic evaluation of the o polysaccharides of the lipopolysaccharides of pseudomonas syringae serogroup o1 strains.	the o polysaccharide (ops) of the lipopolysaccharide (lps) of pseudomonas syringae pv. atrofaciens imv 7836 and some other strains that are classified in serogroup o1 was shown to be a novel linear alpha-d-rhamnan with the tetrasaccharide o repeat -->3)-alpha-d-rhap-(1-->3)-alpha-d-rhap-(1-->2)-alpha-d-r hap-(1-->2)- alpha-d-rhap-(1--> (chemotype 1a). the same alpha-d-rhamnan serves as the backbone in branched opss with lateral (alpha1-->3)-linked d-rhap, (beta1-->4)-linked d-glcpnac, and (alpha ...	1999	10559159