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
estimating photosynthesis and concurrent export rates in c3 and c4 species at ambient and elevated co21,2	the ability of 21 c3 and c4 monocot and dicot species to rapidly export newly fixed c in the light at both ambient and enriched co2 levels was compared. photosynthesis and concurrent export rates were estimated during isotopic equilibrium of the transport sugars using a steady-state 14co2-labeling procedure. at ambient co2 photosynthesis and export rates for c3 species were 5 to 15 and 1 to 10 &mgr;mol c m-2 s-1, respectively, and 20 to 30 and 15 to 22 &mgr;mol c m-2 s-1, respectively, for c4 sp ...	1998	9576790
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
monitoring impact of a pesticide treatment on bacterial soil communities by metabolic and genetic fingerprinting in addition to conventional testing procedures.	herbogil (dinoterb), a reference herbicide, the mineral oil oleo (paraffin oil used as an additive to herbicides), and goltix (metamitron) were taken as model compounds for the study of impacts on microbial soil communities. after the treatment of soil samples, effects on metabolic sum parameters were determined by monitoring substrate-induced respiration (sir) and dehydrogenase activity, as well as carbon and nitrogen mineralization. these conventional ecotoxicological testing procedures are us ...	1998	9687435
the aroq and phea domains of the bifunctional p-protein from xanthomonas campestris in a context of genomic comparison.	the gene (denoted aroqp.phea) encoding the bifunctional p-protein (chorismate mutase-p/prephenate dehydratase) from xanthomonas campestris was cloned. aroqp.phea is essential for l-phenylalanine biosynthesis. dna sequencing of the smallest subclone capable of functional complementation of an escherichia coli phenylalanine auxotroph revealed a putative open reading frame (orf) of 1200 bp that would encode a 43,438-da protein. aroqp.phea exhibited 51% amino acid identity with a pseudomonas stutzer ...	1997	9689222
d-subgenome bias of xcm resistance genes in tetraploid gossypium (cotton) suggests that polyploid formation has created novel avenues for evolution.	a detailed rflp map was used to determine the chromosomal locations and subgenomic distributions of cotton (gossypium) genes/qtls that confer resistance to the bacterial blight pathogen, xanthomonas campestris pv. malvacearum (xcm). genetic mapping generally corroborated classic predictions regarding the number and dosage effects of genes conferring xcm resistance. one recessive allele (b6) was a noteworthy exception to the genetic dominance of most plant resistance alleles. this recessive allel ...	1998	9691052
one of two osmc homologs in bacillus subtilis is part of the sigmab-dependent general stress regulon.	in this report we present the identification and analysis of two bacillus subtilis genes, ykla and ykza, which are homologous to the partially rpos-controlled osmc gene from escherichia coli. the ykla gene is expressed at higher levels in minimal medium than in rich medium and is driven by a putative vegetative promoter. expression of ykza is not medium dependent but increases dramatically when cells are exposed to stress and starvation. this stress-induced increase in ykza expression is absolut ...	1998	9696771
genetically engineered broad-spectrum disease resistance in tomato.	resistance in tomato to the bacterial pathogen pseudomonas syringae pathovar tomato requires pto and prf. mutations that eliminate prf show a loss of both pto resistance and sensitivity to the organophosphate insecticide fenthion, suggesting that prf controls both phenotypes. herein, we report that the overexpression of prf leads to enhanced resistance to a number of normally virulent bacterial and viral pathogens and leads to increased sensitivity to fenthion. these plants express levels of sal ...	1998	9707642
different requirements for eds1 and ndr1 by disease resistance genes define at least two r gene-mediated signaling pathways in arabidopsis.	the arabidopsis genes eds1 and ndr1 were shown previously by mutational analysis to encode essential components of race-specific disease resistance. here, we examined the relative requirements for eds1 and ndr1 by a broad spectrum of resistance (r) genes present in three arabidopsis accessions (columbia, landsberg-erecta, and wassilewskija). we show that there is a strong requirement for eds1 by a subset of r loci (rpp2, rpp4, rpp5, rpp21, and rps4), conferring resistance to the biotrophic oomyc ...	1998	9707643
counterselectable markers: untapped tools for bacterial genetics and pathogenesis.		1998	9712740
molecular characterization and sequence of a methionine biosynthetic locus from pseudomonas syringae.	two methionine biosynthetic genes in pseudomonas syringae pv. syringae, metx and metw, were isolated, sequenced, and evaluated for their roles in methionine biosynthesis and bacterial fitness on leaf surfaces. the metxw locus was isolated on a 1.8-kb dna fragment that was required for both methionine prototrophy and wild-type epiphytic fitness. sequence analysis identified two consecutive open reading frames (orfs), and in vitro transcription-translation experiments provided strong evidence that ...	1998	9721288
characterization of the hrpc and hrprs operons of pseudomonas syringae pathovars syringae, tomato, and glycinea and analysis of the ability of hrpf, hrpg, hrcc, hrpt, and hrpv mutants to elicit the hypersensitive response and disease in plants.	the species pseudomonas syringae encompasses plant pathogens with differing host specificities and corresponding pathovar designations. p. syringae requires the hrp (type iii protein secretion) system, encoded by a 25-kb cluster of hrp and hrc genes, in order to elicit the hypersensitive response (hr) in nonhosts or to be pathogenic in hosts. dna sequence analysis of the hrpc and hrprs operons of p. syringae pv. syringae 61 (brown spot of beans), p. syringae pv. glycinea u1 (bacterial blight of ...	1998	9721291
negative regulation of hrp genes in pseudomonas syringae by hrpv.	mutations in the five hrp and hrc genes in the hrpc operon of the phytopathogen pseudomonas syringae pv. syringae 61 have different effects on bacterial interactions with host and nonhost plants. the hrcc gene within the hrpc operon encodes an outer membrane component of the hrp secretion system that is conserved in all type iii protein secretion systems and is required for most pathogenic phenotypes and for secretion of the hrpz harpin to the bacterial milieu. the other four genes (in order), h ...	1998	9721292
cloning, nucleotide sequence, and expression in escherichia coli of levansucrase genes from the plant pathogens pseudomonas syringae pv. glycinea and p. syringae pv. phaseolicola.	plant-pathogenic bacteria produce various extracellular polysaccharides (epss) which may function as virulence factors in diseases caused by these bacteria. the eps levan is synthesized by the extracellular enzyme levansucrase in pseudomonas syringae, erwinia amylovora, and other bacterial species. the lsc genes encoding levansucrase from p. syringae pv. glycinea pg4180 and p. syringae pv. phaseolicola ncppb 1321 were cloned, and their nucleotide sequences were determined. heterologous expressio ...	1998	9726857
initial transformations in the biodegradation of benzothiazoles by rhodococcus isolates.	benzothiazole-2-sulfonate (btso3) is one of the side products occurring in 2-mercaptobenzothiazole (mbt) production wastewater. we are the first to isolate an axenic culture capable of btso3 degradation. the isolate was identified as a rhodococcus erythropolis strain and also degraded 2-hydroxybenzothiazole (obt) and benzothiazole (bt), but not mbt, which was found to inhibit the biodegradation of obt, bt, and btso3. in anaerobic resting cell assays, btso3 was transformed into obt in stoichiomet ...	1998	9726870
molecular identification of a stenotrophomonas species used in the bioassay for erythromycin in aquaculture samples.	a bacterial strain isolated from aquaculture pond slurry, which was extremely sensitive to erythromycin, was used to detect erythromycin at levels as low as 0.05 micrograms ml-1 in aquaculture water, sediments and soil samples. identification of the indicator organism was attempted by 16s rrna sequencing, biochemical profile, fatty-acid analysis and polymerase chain reaction (pcr). genbank comparison showed that the 16s rrna sequence of the strain was similar to those of more than 20 copies of x ...	1998	9727203
molecular and biotechnological aspects of microbial proteases.	proteases represent the class of enzymes which occupy a pivotal position with respect to their physiological roles as well as their commercial applications. they perform both degradative and synthetic functions. since they are physiologically necessary for living organisms, proteases occur ubiquitously in a wide diversity of sources such as plants, animals, and microorganisms. microbes are an attractive source of proteases owing to the limited space required for their cultivation and their ready ...	1998	9729602
insertion sequences.	insertion sequences (iss) constitute an important component of most bacterial genomes. over 500 individual iss have been described in the literature to date, and many more are being discovered in the ongoing prokaryotic and eukaryotic genome-sequencing projects. the last 10 years have also seen some striking advances in our understanding of the transposition process itself. not least of these has been the development of various in vitro transposition systems for both prokaryotic and eukaryotic e ...	1998	9729608
hrpw of erwinia amylovora, a new harpin that contains a domain homologous to pectate lyases of a distinct class.	harpins, such as hrpn of erwinia amylovora, are extracellular glycine-rich proteins that elicit the hypersensitive reaction (hr). we identified hrpw of e. amylovora, which encodes a protein similar to known harpins in that it is acidic, rich in glycine and serine, and lacks cysteine. a putative hrpl-dependent promoter was identified upstream of hrpw, and western blot analysis of hrpl mutants indicated that the production of hrpw is regulated by hrpl. hrpw is secreted via the hrp (type iii) pathw ...	1998	9748455
the pseudomonas syringae pv. tomato hrpw protein has domains similar to harpins and pectate lyases and can elicit the plant hypersensitive response and bind to pectate.	the host-specific plant pathogen pseudomonas syringae elicits the hypersensitive response (hr) in nonhost plants and secretes the hrpz harpin in culture via the hrp (type iii) secretion system. previous genetic evidence suggested the existence of another harpin gene in the p. syringae genome. hrpw was found in a region adjacent to the hrp cluster in p. syringae pv. tomato dc3000. hrpw encodes a 42. 9-kda protein with domains resembling harpins and pectate lyases (pels), respectively. hrpw has ke ...	1998	9748456
xanthan lyase of bacillus sp. strain gl1 liberates pyruvylated mannose from xanthan side chains.	when the bacterium bacillus sp. strain gl1 was grown in a medium containing xanthan as the carbon source, the viscosity of the medium decreased in association with growth, showing that the bacterium had xanthan-depolymerizing enzymes. one of the xanthan-depolymerizing enzymes (xanthan lyase) was present in the medium and was found to be induced by xanthan. the xanthan lyase purified from the culture fluid was a monomer with a molecular mass of 75 kda, and was most active at ph 5.5 and 50 degrees ...	1998	9758797
genetic characterization of pseudomonas syringae pv. syringae strains from stone fruits in california	strains of pseudomonas syringae pv. syringae were isolated from healthy and diseased stone fruit tissues sampled from 43 orchard sites in california in 1995 and 1996. these strains, together with p. syringae strains from other hosts and pathovars, were tested for pathogenicity and the presence of the syrb and syrc genes and were genetically characterized by using enterobacterial repetitive intergenic consensus (eric) primers and pcr. all 89 strains of p. syringae pv. syringae tested were moderat ...	1998	9758805
relatedness of strains of xanthomonas fragariae by restriction fragment length polymorphism, dna-dna reassociation, and fatty acid analyses	the levels of relatedness of strains of xanthomonas fragariae collected over several years from locations in canada and the united states were compared by determining fatty acid methyl ester profiles, restriction fragment length polymorphisms (rflp) based on pulsed-field gel electrophoresis (pfge) analysis, and dna-dna reassociation values. based on qualitative and quantitative differences in fatty acid profiles, the strains were divided into nine groups and four groups by the midi "10% rule" an ...	1998	9758826
pcr-based detection of the causal agent of watermark disease in willows (salix spp.)	the watermark disease, caused by brenneria salicis (formerly erwinia salicis), is of significant concern wherever tree-forming willows are grown or occur naturally. the movement of infected, asymptomatic cuttings is a major cause of pathogen dispersal. a reliable and sensitive diagnostic procedure is necessary for the safe movement of willow planting material. we derived primers from the nucleotide sequence of the 16s rrna gene of b. salicis for the development of a pcr to detect this pathogen. ...	1998	9758827
xanthan gum biosynthesis and application: a biochemical/genetic perspective.	xanthan gum is a complex exopolysaccharide produced by the plant-pathogenic bacterium xanthomonas campestris pv. campestris. it consists of d-glucosyl, d-mannosyl, and d-glucuronyl acid residues in a molar ratio of 2:2:1 and variable proportions of o-acetyl and pyruvyl residues. because of its physical properties, it is widely used as a thickener or viscosifier in both food and non-food industries. xanthan gum is also used as a stabilizer for a wide variety of suspensions, emulsions, and foams. ...	1998	9763683
iron-responsive gene regulation in a campylobacter jejuni fur mutant.	the expression of iron-regulated systems in gram-negative bacteria is generally controlled by the fur protein, which represses the transcription of iron-regulated promoters by using fe2+ as a cofactor. mutational analysis of the campylobacter jejuni fur gene was carried out by generation of a set of mutant copies of fur which had a kanamycin or chloramphenicol resistance gene introduced into the regions encoding the n and c termini of the fur protein. the mutated genes were recombined into the c ...	1998	9765558
novel rkp gene clusters of sinorhizobium meliloti involved in capsular polysaccharide production and invasion of the symbiotic nodule: the rkpk gene encodes a udp-glucose dehydrogenase.	the production of exopolysaccharide (eps) was shown to be required for the infection process by rhizobia that induce the formation of indeterminate nodules on the roots of leguminous host plants. in sinorhizobium meliloti (also known as rhizobium meliloti) rm41, a capsular polysaccharide (kps) analogous to the group ii k antigens of escherichia coli can replace eps during symbiotic nodule development and serve as an attachment site for the strain-specific bacteriophage phi16-3. the rkpa to -j ge ...	1998	9765575
hpaa mutants of xanthomonas campestris pv. vesicatoria are affected in pathogenicity but retain the ability to induce host-specific hypersensitive reaction.	xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease on pepper and tomato plants. we reported previously that the main hrp (hypersensitive reaction and pathogenicity) gene cluster in x. c. pv. vesicatoria contains six transcription units, designated hrpa to hrpf. we present here the sequence of the hrpd operon and an analysis of non-polar mutants in each of the six genes. three genes, hrcq, hrcr and hrcs, are predicted to encode conserved components of type iii pr ...	1998	9781876
the yersinia deadly kiss.		1998	9791096
endochitinase is transported to the extracellular milieu by the eps-encoded general secretory pathway of vibrio cholerae.	the chia gene of vibrio cholerae encodes a polypeptide which degrades chitin, a homopolymer of n-acetylglucosamine (glcnac) found in cell walls of fungi and in the integuments of insects and crustaceans. chia has a coding capacity corresponding to a polypeptide of 846 amino acids having a predicted molecular mass of 88.7 kda. a 52-bp region with promoter activity was found immediately upstream of the chia open reading frame. insertional inactivation of the chromosomal copy of the gene confirmed ...	1998	9791107
the phenolic recognition profiles of the agrobacterium tumefaciens vira protein are broadened by a high level of the sugar binding protein chve.	the formation of crown gall tumors by agrobacterium tumefaciens requires that the virulence (vir) genes be induced by chemical signals which consist of specific phenolic compounds and monosaccharides, synthesized at plant wound sites. signal transduction in the activation of these genes is mediated by the vira-virg two-component regulatory system, together with chve, a glucose-galactose binding protein which interacts with vira. we have previously presented genetic evidence that vira senses phen ...	1998	9791112
a metalloprotease from xanthomonas campestris that specifically degrades proline/hydroxyproline-rich glycoproteins of the plant extracellular matrix.	culture supernatants of xanthomonas campestris pv. campestris contain an enzymic activity capable of degrading gp120, a proline-rich glycoprotein associated with the extracellular matrix of the vascular bundles in petioles of turnip (brassica campestris). this activity did not reside in any of the three previously characterized proteases of x. campestris pv. campestris that were identified by their action against the model substrate beta-casein. the novel enzyme was purified by ion-exchange and ...	1998	9805395
localized changes in peroxidase activity accompany hydrogen peroxide generation during the development of a nonhost hypersensitive reaction in lettuce	peroxidase activity was characterized in lettuce (lactuca sativa l.) leaf tissue. changes in the activity and distribution of the enzyme were examined during the development of a nonhost hypersensitive reaction (hr) induced by pseudomonas syringae (p. s.) pv phaseolicola and in response to an hrp mutant of the bacterium. assays of activity in tissue extracts revealed ph optima of 4.5, 6.0, 5.5 to 6.0, and 6.0 to 6.5 for the substrates tetramethylbenzidine, guaiacol, caffeic acid, and chlorogenic ...	1998	9808752
adherence of the gram-positive bacterium ruminococcus albus to cellulose and identification of a novel form of cellulose-binding protein which belongs to the pil family of proteins.	the adherence of ruminococcus albus 8 to crystalline cellulose was studied, and an affinity-based assay was also used to identify candidate cellulose-binding protein(s). bacterial adherence in cellulose-binding assays was significantly increased by the inclusion of either ruminal fluid or micromolar concentrations of both phenylacetic and phenylpropionic acids in the growth medium, and the addition of carboxymethylcellulose (cmc) to assays decreased the adherence of the bacterium to cellulose. a ...	1998	9811650
the type iv leader peptidase/n-methyltransferase of vibrio vulnificus controls factors required for adherence to hep-2 cells and virulence in iron-overloaded mice.	vibrio vulnificus expresses a number of potential virulence determinants that may contribute to its ability to cause a severe and rapidly disseminating septicemia in susceptible hosts. we have cloned and characterized two genes encoding products related to components of the type iv pilus biogenesis and general secretory (type ii) pathways by complementation of a type iv peptidase/n-methyltransferase (pild) mutant of pseudomonas aeruginosa with a v. vulnificus genomic library. one of the genes (v ...	1998	9826339
assessment of changes in microbial community structure during operation of an ammonia biofilter with molecular tools.	biofiltration has been used for two decades to remove odors and various volatile organic and inorganic compounds in contaminated off-gas streams. although biofiltration is widely practiced, there have been few studies of the bacteria responsible for the removal of air contaminants in biofilters. in this study, molecular techniques were used to identify bacteria in a laboratory-scale ammonia biofilter. both 16s rrna and ammonia monooxygenase (amoa) genes were used to characterize the heterotrophi ...	1998	9835577
sinorhizobium fredii and sinorhizobium meliloti produce structurally conserved lipopolysaccharides and strain-specific k antigens.	lipopolysaccharides (lps) and capsular polysaccharides (k antigens) may influence the interaction of rhizobia with their specific hosts; therefore, we conducted a comparative analysis of sinorhizobium fredii and sinorhizobium meliloti, which are genetically related, yet symbiotically distinct, nitrogen-fixing microsymbionts of legumes. we found that both species typically produce strain-specific k antigens that consist of 3-deoxy-d-manno-2-octulosonic acid (kdo), or other 1-carboxy-2-keto-3-deox ...	1998	9835585
the virulence plasmid of yersinia, an antihost genome.	the 70-kb virulence plasmid enables yersinia spp. (yersinia pestis, y. pseudotuberculosis, and y. enterocolitica) to survive and multiply in the lymphoid tissues of their host. it encodes the yop virulon, an integrated system allowing extracellular bacteria to disarm the cells involved in the immune response, to disrupt their communications, or even to induce their apoptosis by the injection of bacterial effector proteins. this system consists of the yop proteins and their dedicated type iii sec ...	1998	9841674
the arabidopsis thaliana rpm1 disease resistance gene product is a peripheral plasma membrane protein that is degraded coincident with the hypersensitive response.	disease resistance in plants is often controlled by a gene-for-gene mechanism in which avirulence (avr) gene products encoded by pathogens are specifically recognized, either directly or indirectly, by plant disease resistance (r) gene products. members of the nbs-lrr class of r genes encode proteins containing a putative nucleotide binding site (nbs) and carboxyl-terminal leucine-rich repeats (lrrs). generally, nbs-lrr proteins do not contain predicted transmembrane segments or signal peptides, ...	1998	9861059
chromosome map of xanthomonas campestris pv. campestris 17 with locations of genes involved in xanthan gum synthesis and yellow pigmentation.	no plasmid was detected in xanthomonas campestris pv. campestris 17, a strain of the causative agent of black rot in cruciferous plants isolated in taiwan. its chromosome was cut by paci, pmei, and swai into five, two, and six fragments, respectively, and a size of 4.8 mb was estimated by summing the fragment lengths in these digests. based on the data obtained from partial digestion and southern hybridization using probes common to pairs of the overlapping fragments or prepared from linking fra ...	1999	9864320
regulation of the sol locus genes for butanol and acetone formation in clostridium acetobutylicum atcc 824 by a putative transcriptional repressor.	a gene (orf1, now designated solr) previously identified upstream of the aldehyde/alcohol dehydrogenase gene aad (r. v. nair, g. n. bennett, and e. t. papoutsakis, j. bacteriol. 176:871-885, 1994) was found to encode a repressor of the sol locus (aad, ctfa, ctfb and adc) genes for butanol and acetone formation in clostridium acetobutylicum atcc 824. primer extension analysis identified a transcriptional start site 35 bp upstream of the solr start codon. amino acid comparisons of solr identified ...	1999	9864345
exopolysaccharide biosynthesis in lactococcus lactis nizo b40: functional analysis of the glycosyltransferase genes involved in synthesis of the polysaccharide backbone.	we used homologous and heterologous expression of the glycosyltransferase genes of the lactococcus lactis nizo b40 eps gene cluster to determine the activity and substrate specificities of the encoded enzymes and established the order of assembly of the trisaccharide backbone of the exopolysaccharide repeating unit. epsd links glucose-1-phosphate from udp-glucose to a lipid carrier, epse and epsf link glucose from udp-glucose to lipid-linked glucose, and epsg links galactose from udp-galactose t ...	1999	9864348
the ecs1 gene of arabidopsis encodes a plant cell wall-associated protein and is potentially linked to a locus influencing resistance to xanthomonas campestris.	the interaction between arabidopsis and xanthomonas campestris pv. campestris (xcc) provides a useful model system to identify components that are involved in incompatible interactions of this phytopathogen and cruciferous plants. we have previously described a new gene from arabidopsis thaliana, ecs1 (formerly cxc750), which showed an ecotype-specific expression pattern, although homologous sequences are present in the genomes of all ecotypes tested. interestingly, ecs1 mrna transcripts were on ...	1998	9869403
effect of oxidative stress on the biosynthesis of 2-c-methyl-d-erythritol-2,4-cyclopyrophosphate and isoprenoids by several bacterial strains.	in this study, the gram-negative bacteria xanthomonas campestris, xanthomonas maltophilia, and pseudomonas putida, facultative parasites of plants and animals, were shown to accumulate 2-c-methyl-d-erythritol-2,4-cyclopyrophosphate (mec) in response to benzyl-viologen-induced oxidative stress. corynebacterium ammoniagenes mutants capable of accumulating mec in the absence of an exogenous oxidative stress inducer were obtained. isoprenoid synthesis and mec synthesis in these and other bacteria we ...	1998	9871022
new mobilizable vectors suitable for gene replacement in gram-negative bacteria and their use in mapping of the 3' end of the xanthomonas campestris pv. campestris gum operon.	we describe useful vectors to select double-crossover events directly in site-directed marker exchange mutagenesis in gram-negative bacteria. these vectors contain the gusa marker gene, providing colorimetric screens to identify bacteria harboring those sequences. the applicability of these vectors was shown by mapping the 3' end of the xanthomonas campestris gum operon, involved in biosynthesis of xanthan.	1999	9872790
overexpression of pto activates defense responses and confers broad resistance.	the tomato disease resistance (r) gene pto specifies race-specific resistance to the bacterial pathogen pseudomonas syringae pv tomato carrying the avrpto gene. pto encodes a serine/threonine protein kinase that is postulated to be activated by a physical interaction with the avrpto protein. here, we report that overexpression of pto in tomato activates defense responses in the absence of the pto-avrpto interaction. leaves of three transgenic tomato lines carrying the cauliflower mosaic virus 35 ...	1999	9878629
regulation of expression of avirulence gene avrrxv and identification of a family of host interaction factors by sequence analysis of avrbst.	resistance in tomato line hawaii 7998 as well as in several nonhost plants to xanthomonas campestris pv. vesicatoria tomato strain (xcvt) is mediated in part by the avirulence gene avrrxv. analysis of growth of wild-type and avrrxv deletion strains indicates that avrrxv plays a crucial role in the ability of xcvt 92-14 to induce resistance on hawaii 7998. we used avrrxv reporter gene fusions and northern (rna) blot analysis to test several growth environments for inductive potential. we found th ...	1999	9885191
identification and characterization of ptlc, an essential component of the pertussis toxin secretion system.	ptlc is a member of a set of proteins necessary for the secretion of pertussis toxin (pt) from bordetella pertussis. using polyclonal antibodies specific for ptlc, we identified ptlc as a protein with an apparent molecular weight of 85,000 that localizes to the membrane fraction of bacterial cell extracts. we found that a mutant strain of b. pertussis that contains an in-frame deletion in ptlc is unable to secrete pt and that pt secretion is fully restored by expressing ptlc in trans, indicating ...	1999	9916087
sequence and function of luxu: a two-component phosphorelay protein that regulates quorum sensing in vibrio harveyi.	vibrio harveyi regulates the expression of bioluminescence (lux) in response to cell density, a phenomenon known as quorum sensing. in v. harveyi, two independent quorum-sensing systems exist, and each produces, detects, and responds to a specific cell density-dependent autoinducer signal. the autoinducers are recognized by two-component hybrid sensor kinases called luxn and luxq, and sensory information from both systems is transduced by a phosphorelay mechanism to the response regulator protei ...	1999	9922254
noll of rhizobium sp. strain ngr234 is required for o-acetyltransferase activity.	following (iso)flavonoid induction, nodulation genes of the symbiotic nitrogen-fixing bacterium rhizobium sp. strain ngr234 elaborate a large family of lipooligosaccharidic nod factors (nodngr factors). when secreted into the rhizosphere of compatible legumes, these signal molecules initiate root hair deformation and nodule development. the nonreducing glucosamine residue of nodngr factors are n acylated, n methylated, and mono- or biscarbamoylated, while position c-6 of the reducing extremity i ...	1999	9922261
cell-specific production and antimicrobial activity of naphthoquinones in roots of lithospermum erythrorhizon	pigmented naphthoquinone derivatives of shikonin are produced at specific times and in specific cells of lithospermum erythrorhizon roots. normal pigment development is limited to root hairs and root border cells in hairy roots grown on "noninducing" medium, whereas induction of additional pigment production by abiotic (cuso4) or biotic (fungal elicitor) factors increases the amount of total pigment, changes the ratios of derivatives produced, and initiates production of pigment de novo in epide ...	1999	9952436
expression and study of recombinant exom, a beta1-4 glucosyltransferase involved in succinoglycan biosynthesis in sinorhizobium meliloti.	here we report on the overexpression and in vitro characterization of a recombinant form of exom, a putative beta1-4 glucosyltransferase involved in the assembly of the octasaccharide repeating subunit of succinoglycan from sinorhizobium meliloti. the open reading frame exom was isolated by pcr and subcloned into the expression vector pet29b, allowing inducible expression under the control of the t7 promoter. escherichia coli bl21(de3)/plyss containing exom expressed a novel 38-kda protein corre ...	1999	9973339
characterization of insertions of is476 and two newly identified insertion sequences, is1478 and is1479, in xanthomonas campestris pv. campestris.	thirty-two plasmid insertion mutants were independently isolated from two strains of xanthomonas campestris pv. campestris in taiwan. of the 32 mutants, 14 (44%), 8 (25%), and 4 (12%) mutants resulted from separate insertions of an is3 family member, is476, and two new insertion sequences (is), is1478 and is1479. while is1478 does not have significant sequence homology with any is elements in the embl/genbank/ddbj database, is1479 demonstrated 73% sequence homology with is1051 in x. campestris p ...	1999	9973349
prhj and hrpg, two new components of the plant signal-dependent regulatory cascade controlled by prha in ralstonia solanacearum.	hrp gene expression in the phytopathogenic bacterium ralstonia solanacearum gmi1000 is induced through the hrpb regulator in minimal medium and upon co-culture with plant cell suspensions. the putative outer membrane protein prha is specifically involved in hrp gene activation in the presence of plant cells and has been proposed to be a receptor of a plant-dependent signal transduction pathway. here, we report on the identification of two regulatory genes, hrpg and prhj, located at the right-han ...	1999	9987125
suppression of bacterial blight by a bacterial community isolated from the guttation fluids of anthuriums	growth and survival of xanthomonas campestris pv. dieffenbachiae in guttation fluids (xylem sap exuded from leaf margins) of anthuriums were suppressed by several bacterial strains indigenous to leaves of various anthurium cultivars. inhibition of growth was not observed in filter-sterilized guttation fluids and was restored to original levels only by reintroducing specific mixtures of bacteria into filter-sterilized guttation fluids. the inhibitory effect was related to the species in the bacte ...	1999	10049858
isolation of ethylene-insensitive soybean mutants that are altered in pathogen susceptibility and gene-for-gene disease resistance	plants commonly respond to pathogen infection by increasing ethylene production, but it is not clear if this ethylene does more to promote disease susceptibility or disease resistance. ethylene production and/or responsiveness can be altered by genetic manipulation. the present study used mutagenesis to identify soybean (glycine max l. merr.) lines with reduced sensitivity to ethylene. two new genetic loci were identified, etr1 and etr2. mutants were compared with isogenic wild-type parents for ...	1999	10069832
the sinorhizobium meliloti insertion sequence (is) elements isrm102f34-1/isrm7 and isrm220-13-5 belong to a new family of insertion sequence elements.	the sinorhizobium meliloti insertion sequence (is) elements isrm102f34-1 and isrm220-13-5 are 1481 and 1550 base pairs (bp) in size, respectively. isrm102f34-1 is bordered by 15 bp imperfect terminal inverted repeat sequences (two mismatches), whereas the terminal inverted repeat of isrm220-13-5 has a length of 16 bp (two mismatches). both insertion sequence elements generate a 6-bp target duplication upon transposition. the putative transposase enzymes of isrm102f34-1 and isrm220-13-5 consist o ...	1999	10079521
mutational analysis of the vaca promoter provides insight into gene transcription in helicobacter pylori.	analysis of 12 helicobacter pylori promoters indicates the existence of a consensus -10 hexamer (tataat) but little conservation of -35 sequences. in this study, mutations in either the h. pylori vaca -10 region or the -35 region resulted in decreased vaca transcription and suggested that an extended -10 motif is utilized. thus, despite the lack of a -35 consensus sequence for h. pylori promoters, the -35 region plays a functional role in vaca transcription.	1999	10094707
cellular locations of pseudomonas syringae pv. syringae hrcc and hrcj proteins, required for harpin secretion via the type iii pathway.	the complete hrp-hrc-hrma cluster of pseudomonas syringae pv. syringae 61 encodes 28 polypeptides. a saprophytic bacterium carrying this cluster is capable of secreting hrpz-a harpin encoded by hrpz-in an hrp-dependent manner, which suggests that this cluster contains sufficient components to assemble functional type iii secretion machinery. sequence data show that hrcj and hrcc are putative outer membrane proteins, and nonpolar mutagenesis demonstrates they are all required for hrpz secretion. ...	1999	10094714
vibrio cholerae o1 el tor: identification of a gene cluster required for the rugose colony type, exopolysaccharide production, chlorine resistance, and biofilm formation.	the rugose colony variant of vibrio cholerae o1, biotype el tor, is shown to produce an exopolysaccharide, epsetr, that confers chlorine resistance and biofilm-forming capacity. epsetr production requires a chromosomal locus, vps, that contains sequences homologous to carbohydrate biosynthesis genes of other bacterial species. mutations within this locus yield chlorine-sensitive, smooth colony variants that are biofilm deficient. the biofilm-forming properties of epsetr may enable the survival o ...	1999	10097157
genetic evidence for the role of gdp-mannose in plant ascorbic acid (vitamin c) biosynthesis.	vitamin c (l-ascorbic acid; asa) acts as a potent antioxidant and cellular reductant in plants and animals. asa has long been known to have many critical physiological roles in plants, yet its biosynthesis is only currently being defined. a pathway for asa biosynthesis that features gdp-mannose and l-galactose has recently been proposed for plants. we have isolated a collection of asa-deficient mutants of arabidopsis thaliana that are valuable tools for testing of an asa biosynthetic pathway. th ...	1999	10097187
intracellular compounds quantification by means of flow cytometry in bacteria: application to xanthan production by xanthomonas campestris.	the use of flow cytometry (fcm) to quantitatively analyze intracellular compounds is studied. fcm is a very useful technique for individual cell studies in microbial systems, and gives access to information which cannot be obtained in any other way. nevertheless, it provides data in arbitrary units, that is, relative data. this analytical technique could be employed for kinetic modeling of microbial systems and even for internal phenomena analysis, but for this purpose, absolute data-that is con ...	1998	10099182
oxygen supply without gas-liquid film resistance to xanthomonas campestris cultivation	alternative methods of oxygen supply are of crucial importance, especially in viscous fermentations and shear-sensitive fermentations. a method of oxygen supply that completely eliminates the gas-liquid transport resistance has been presented. the method involves a need-based liquid-phase decomposition of hydrogen peroxide to provide the necessary oxygen. when xanthomonas campestris was cultivated (viscous cultivation) using this method of oxygen supply, dissolved oxygen (do) levels were maintai ...	1998	10099392
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
molecular analysis of microbial community structures in pristine and contaminated aquifers: field and laboratory microcosm experiments.	this study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (fc) or aerobic and noncontaminated (nc) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). the latter objective was addressed by using the nc and fc aquifer materials for anaerobic microcosm studie ...	1999	10224013
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