Publications

subset of hybrid eukaryotic proteins is exported by the type i secretion system of erwinia chrysanthemi.	erwinia chrysanthemi exports degradative enzymes by using a type i protein secretion system. the proteases secreted by this system lack an n-terminal signal peptide but contain a c-terminal secretion signal. to explore the substrate specificity of this system, we have expressed the e. chrysanthemi transporter system (prtdef genes) in escherichia coli and tested the ability of this abc transporter to export hybrid proteins carrying c-terminal fragments of e. chrysanthemi protease b. the c terminu ...	2001	11157948
potential symbiosis-specific genes uncovered by sequencing a 410-kilobase dna region of the bradyrhizobium japonicum chromosome.	the physical and genetic map of the bradyrhizobium japonicum chromosome revealed that nitrogen fixation and nodulation genes are clustered. because of the complex interactions between the bacterium and the plant, we expected this chromosomal sector to contain additional genes that are involved in the maintenance of an efficient symbiosis. therefore, we determined the nucleotide sequence of a 410-kb region. the overall g+c nucleotide content was 59.1%. using a minimum gene length of 150 nucleotid ...	2001	11157954
the arabidopsis isr1 locus controlling rhizobacteria-mediated induced systemic resistance is involved in ethylene signaling.	in arabidopsis, the rhizobacterial strain pseudomonas fluorescens wcs417r triggers an induced systemic resistance (isr) response that is effective against different types of pathogens. the isr signaling pathway functions independent of salicylic acid, but requires responsiveness to jasmonate (ja) and ethylene. using the genetic variability of isr inducibility between arabidopsis accessions, we recently identified a locus (isr1) on chromosome iii that is involved in isr signaling. accessions rld ...	2001	11161023
the hexy genes of erwinia carotovora ssp. carotovora and ssp. atroseptica encode novel proteins that regulate virulence and motility co-ordinately.	mutations located in a new gene, hexy, in erwinia carotovora ssp. carotovora (ecc) and ssp. atroseptica (eca) cause strong upregulation of production of exoenzyme virulence factors and motility. the hexy gene encodes a novel 14.4 kda protein with no known homologues. the hexy mrna transcript has an unusually long (525bp) 5' untranslated region, which may be important for post-transcriptional regulation. an elevated level of transcription of two exoenzyme genes, pelcand celv, was observed in the ...	1999	11207775
exchange of xcp (gsp) secretion machineries between pseudomonas aeruginosa and pseudomonas alcaligenes: species specificity unrelated to substrate recognition.	pseudomonas aeruginosa and pseudomonas alcaligenes are gram-negative bacteria that secrete proteins using the type ii or general secretory pathway, which requires at least 12 xcp gene products (xcpa and xcpp to -z). despite strong conservation of this secretion pathway, gram-negative bacteria usually cannot secrete exoproteins from other species. based on results obtained with erwinia, it has been proposed that the xcpp and/or xcpq homologs determine this secretion specificity (m. linderberg, g. ...	2001	11208795
hexa of erwinia carotovora ssp. carotovora strain ecc71 negatively regulates production of rpos and rsmb rna, a global regulator of extracellular proteins, plant virulence and the quorum-sensing signal, n-(3-oxohexanoyl)-l-homoserine lactone.	the soft-rotting bacterium, erwinia carotovora ssp. carotovora (e. c. carotovora), produces an array of extracellular enzymes (= exoenzymes), including pectate lyase (pel), polygalacturonase (peh), cellulase (cel) and protease (prt), as well as harpinecc, the elicitor of hypersensitive reaction (hr). the production of these exoenzymes and harpinecc responds to plant products and the quorum-sensing signal [n-(3-oxohexanoyl)-l-homoserine lactone; ohl] and is subject to both transcriptional and pos ...	2000	11220306
the pleiotropic two-component regulatory system phop-phoq.		2001	11222580
molecular characterization of global regulatory rna species that control pathogenicity factors in erwinia amylovora and erwinia herbicola pv. gypsophilae.	rsmb(ecc) specifies a nontranslatable rna regulator that controls exoprotein production and pathogenicity in soft rot-causing erwinia carotovora subsp. carotovora. this effect of rsmb(ecc) rna is mediated mostly by neutralizing the function of rsma(ecc), an rna-binding protein of e. carotovora subsp. carotovora, which acts as a global negative regulator. to determine the occurrence of functional homologs of rsmb(ecc) in non-soft-rot-causing erwinia species, we cloned the rsmb genes of e. amylovo ...	2001	11222584
phylogeny of genes for secretion ntpases: identification of the widespread tada subfamily and development of a diagnostic key for gene classification.	macromolecular transport systems in bacteria currently are classified by function and sequence comparisons into five basic types. in this classification system, type ii and type iv secretion systems both possess members of a superfamily of genes for putative ntp hydrolase (ntpase) proteins that are strikingly similar in structure, function, and sequence. these include virb11, trbb, trag, gspe, pilb, pilt, and comg1. the predicted protein product of tada, a recently discovered gene required for t ...	2001	11226268
acyl-homoserine lactone production is more common among plant-associated pseudomonas spp. than among soilborne pseudomonas spp.	a total of 137 soilborne and plant-associated bacterial strains belonging to different pseudomonas species were tested for their ability to synthesize n-acyl-homoserine lactones (nahl). fifty-four strains synthesized nahl. interestingly, nahl production appears to be more common among plant-associated than among soilborne pseudomonas spp. indeed, 40% of the analyzed pseudomonas syringae strains produced nahl which were identified most often as the short-chain nahl, n-hexanoyl-l-homoserine lacton ...	2001	11229911
the rssb response regulator directly targets sigma(s) for degradation by clpxp.	the sigma(s) subunit of escherichia coli rna polymerase regulates the expression of stationary phase and stress response genes. control over sigma(s) activity is exercised in part by regulated degradation of sigma(s). in vivo, degradation requires the clpxp protease together with rssb, a protein homologous to response regulator proteins. using purified components, we reconstructed the degradation of sigma(s) in vitro and demonstrate a direct role for rssb in delivering sigma(s) to clpxp. rssb gr ...	2001	11238382
methods for detecting acylated homoserine lactones produced by gram-negative bacteria and their application in studies of ahl-production kinetics.	in the process of evaluating the role of acylated homoserine lactones (ahls) in food-spoiling gram-negative bacteria, we have combined a range of bacterial ahl monitor systems to determine the ahl-profile and the kinetics of ahl-production. ahl production from 148 strains of enterobacteriaceae isolated from foods was tested using escherichia coli psb403 (luxr), agrobacterium tumefaciens a136 (trar) and both induction and inhibition of chromobacterium violaceum cv026 (cvir). all strains except on ...	2001	11240047
sira orthologs affect both motility and virulence.	the sira gene of salmonella enterica serovar typhimurium encodes a two-component response regulator of the fixj family that has a positive regulatory influence on the expression of type iii secretion genes involved with epithelial cell invasion and the elicitation of bovine gastroenteritis. sira orthologs in pseudomonas, vibrio, and erwinia control the expression of distinct virulence genes in these genera, but an evolutionarily conserved target of sira regulation has never been identified. in t ...	2001	11244064
agricultural microbes genome 2: first glimpses into the genomes of plant-associated microbes.		2001	11251088
an inner membrane platform in the type ii secretion machinery of gram-negative bacteria.	the type ii secretion machinery allows most gram-negative bacteria to deliver virulence factors into their surroundings. we report that in erwinia chrysanthemi, gspe (the putative ntpase), gspf, gspl and gspm constitute a complex in the inner membrane that is presumably used as a platform for assembling other parts of the secretion machinery. the gspe-gspf-gspl-gspm complex was demonstrated by two methods: (i) co-immunoprecipitation of gspe-gspf-gspl with antibodies raised against either gspe or ...	2001	11266368
the drosophila caspase dredd is required to resist gram-negative bacterial infection.	the drosophila innate immune system discriminates between pathogens and responds by inducing the expression of specific antimicrobial peptide-encoding genes through distinct signaling cascades. fungal infection activates nf-kappab-like transcription factors via the toll pathway, which also regulates innate immune responses in mammals. the pathways that mediate antibacterial defenses, however, are less defined. we have isolated loss-of-function mutations in the caspase encoding gene dredd, which ...	2000	11269502
the effect of polysialylation on the immunogenicity and antigenicity of asparaginase: implication in its pharmacokinetics.	erwinia carotovora l-asparaginase was conjugated via the epsilon-amino groups of its lysine residues with colominic acid (ca) (polysialic acid) of average molecular mass of 10 kda by reductive amination in the presence of nacnbh3. polysialylation using 50-, 100- and 250-fold molar excess ca relative to the enzyme led to an increasing proportion of the enzyme's in-amino groups (5.8, 7.6 and 11.3%, respectively) being conjugated to ca. polysialylated and native (intact) asparaginase were used to i ...	2001	11292557
mapping stress-induced changes in autoinducer ai-2 production in chemostat-cultivated escherichia coli k-12.	numerous gram-negative bacteria employ a cell-to-cell signaling mechanism, termed quorum sensing, for controlling gene expression in response to population density. recently, this phenomenon has been discovered in escherichia coli, and while pathogenic e. coli utilize quorum sensing to regulate pathogenesis (i.e., expression of virulence genes), the role of quorum sensing in nonpathogenic e. coli is less clear, and in particular, there is no information regarding the role of quorum sensing durin ...	2001	11292813
study of the role of antimicrobial glucosinolate-derived isothiocyanates in resistance of arabidopsis to microbial pathogens.	crude aqueous extracts from arabidopsis leaves were subjected to chromatographic separations, after which the different fractions were monitored for antimicrobial activity using the fungus neurospora crassa as a test organism. two major fractions were obtained that appeared to have the same abundance in leaves from untreated plants versus leaves from plants challenge inoculated with the fungus alternaria brassicicola. one of both major antimicrobial fractions was purified to homogeneity and iden ...	2001	11299350
effects of the two-component system comprising gaca and gacs of erwinia carotovora subsp. carotovora on the production of global regulatory rsmb rna, extracellular enzymes, and harpinecc.	posttranscriptional regulation mediated by the regulator of secondary metabolites (rsm) rsma-rsmb pair is the most important factor in the expression of genes for extracellular enzymes and harpinecc in erwinia carotovora subsp. carotovora. rsma is a small rna-binding protein, which acts by lowering the half-life of a mrna species. rsmb specifies an untranslated regulatory rna and neutralizes the rsma effect. it has been speculated that gaca-gacs, members of a two-component system, may affect gen ...	2001	11310739
optimization of fermentation conditions for preparation of polygalacturonic acid transeliminase by erwinia carotovora ifo3830.	this paper is concerned with optimization of the fermentation conditions for preparation of alkaline pectin lyase (poly-galacturonic acid trans-eliminase, pate) by erwinia carotovora ifo3830 (e.c.ifo3830). the orthogonal matrix method was adopted as the experimental design method for media. the effects of media composition on the growth rate of e.c.ifo3830 are in the order of pectin > kh(2)po(4)/na(2)hpo(4) > mgso(4) > (nh(4))(2)so(4) > glucose > l-glutamate sodium, and those on pate activity ar ...	2001	11312709
molecular characterization of an endopolygalacturonase from fusarium oxysporum expressed during early stages of infection.	the tomato vascular wilt pathogen fusarium oxysporum f. sp. lycopersici produces an array of pectinolytic enzymes that may contribute to penetration and colonization of the host plant. here we report the isolation of pg5, encoding a novel extracellular endopolygalacturonase (endopg) that is highly conserved among different formae speciales of f. oxysporum. the putative mature pg5 product has a calculated molecular mass of 35 kda and a pi of 8.3 and is more closely related to endopgs from other f ...	2001	11319099
osmoregulated periplasmic glucan synthesis is required for erwinia chrysanthemi pathogenicity.	erwinia chrysanthemi is a phytopathogenic enterobacterium causing soft rot disease in a wide range of plants. osmoregulated periplasmic glucans (opgs) are intrinsic components of the gram-negative bacterial envelope. we cloned the opggh operon of e. chrysanthemi, encoding proteins involved in the glucose backbone synthesis of opgs, by complementation of the homologous locus mdogh of escherichia coli. opgg and opgh show a high level of similarity with mdog and mdoh, respectively, and mutations in ...	2001	11325942
the pdz domain of outc and the n-terminal region of outd determine the secretion specificity of the type ii out pathway of erwinia chrysanthemi.	the plant pathogens erwinia chrysanthemi and erwinia carotovora secrete multiple exoproteins by a type ii pathway, the out system. secretion in erwinia is species-specific: exoproteins of one species cannot be secreted by the other. we analysed the role of two components of the out system, the bitopic inner membrane protein outc and the secretin outd, in the specific recognition of secreted proteins. we demonstrated that the pdz domain of outc determines its secretion specificity towards certain ...	2001	11327762
physico-chemical analysis of lipid a fractions of lipopolysaccharide from erwinia carotovora in relation to bioactivity.	highly purified bisphosphoryl, monophosphoryl and dephosphoryl lipids a from erwinia carotovora with different acylation patterns were characterized physico-chemically. applying matrix assisted laser desorption/ionization mass spectrometry, the purity of the lipid a fractions was determined, and from monolayer measurements the molecular space requirement was estimated. fourier transform infrared spectroscopy allowed the elucidation of the gel to liquid crystalline phase transition of the acyl ch ...	2001	11342157
polarity in action: asymmetric protein localization in bacteria.		2001	11344132
type ii secretion and pathogenesis.		2001	11349009
mycobacterium bovis bcg reca deletion mutant shows increased susceptibility to dna-damaging agents but wild-type survival in a mouse infection model.	pathogenic microorganisms possess antioxidant defense mechanisms for protection from reactive oxygen metabolites which are generated during the respiratory burst of phagocytic cells. these defense mechanisms include enzymes such as catalase, which detoxifies reactive oxygen species, and dna repair systems, which repair damage resulting from oxidative stress. to (i) determine the relative importance of the dna repair system when oxidative stress is encountered by the mycobacterium tuberculosis co ...	2001	11349014
quorum sensing controls the synthesis of virulence factors by modulating rsma gene expression in erwinia carotovora subsp. carotovora.	the plant-pathogenic bacterium erwinia carotovora subsp. carotovora (ecc) causes disease mainly by means of a number of extracellular plant cell wall-degrading enzymes (pcwdes), also referred to as virulence factors. the production of pcwdes is coordinately activated by the diffusible signal molecule n-acyl-homoserine lactone (hsl) in a population density-dependent manner ("quorum sensing"). expi is the enzyme responsible for the synthesis of hsl. the rsm system negatively regulates the producti ...	2001	11361339
the luxm homologue vanm from vibrio anguillarum directs the synthesis of n-(3-hydroxyhexanoyl)homoserine lactone and n-hexanoylhomoserine lactone.	vibrio anguillarum, which causes terminal hemorrhagic septicemia in fish, was previously shown to possess a luxri-type quorum-sensing system (vanri) and to produce n-(3-oxodecanoyl)homoserine lactone (3-oxo-c10-hsl). however, a vani null mutant still activated n-acylhomoserine lactone (ahl) biosensors, indicating the presence of an additional quorum-sensing circuit in v. anguillarum. in this study, we have characterized this second system. using high-pressure liquid chromatography in conjunction ...	2001	11371516
[processes of plant colonization by methylobacterium strains and some bacterial properties ].	the pink-pigmented facultative methylotrophic bacteria (ppfmb) of the genus methylobacterium are indespensible inhabitants of the plant phyllosphere. using maize zea mays as a model, the ways of plant colonization by ppfmb and some properties of the latter that might be beneficial to plants were studied. a marked strain, methylobacterium mesophilicum apr-8 (pulb113), was generated to facilitate the detection of the methylotrophic bacteria inoculated into the soil or applied to the maize leaves. ...	2001	11386061
[adsorbed receptors for erwinia carotovor subsp. carotovora macromolecular bacteriocins].	study of nature of receptors for macromolecular bacteriocins erwinia carotovora subsp. carotovora has shown that lipopolysaccharide (lps) of cell membrane is an attaching structure for them. it has been established that enzymic treatment of lps preparation with its further deproteinization by phenol is necessary for isolation of biologically active lipopolysaccharide. the process of absorption by lps has been studied quantitatively and it has been shown that it is a low-efficient receptor as com ...	2001	11392768
[characteristics of bacterial lipopolysaccharides depending on extraction method].	carbohydrate-containing biopolymers have been isolated from erwinia carotovora subsp. atroseptica 549 by two methods--the aqueous-phenol and with using physiological solution--with addition and without addition of ethylenediaminetetraacetate (edta). the biopolymers yield from the cells of bacteria are shown to depend on the extraction method. lipopolysaccharide-protein complex have been isolated by the sparing method. the purest lipopolysaccharide have been isolated by the aqueousphenol method. ...	2000	11392785
jasmonate-dependent induction of indole glucosinolates in arabidopsis by culture filtrates of the nonspecific pathogen erwinia carotovora.	elicitors from the plant pathogen erwinia carotovora trigger coordinate induction of the tryptophan (trp) biosynthesis pathway and trp oxidizing genes in arabidopsis. to elucidate the biological role of such pathogen-induced activation we characterized the production of secondary defense metabolites such as camalexin and indole glucosinolates derived from precursors of this pathway. elicitor induction was followed by a specific increase in 3-indolylmethylglucosinolate (igs) content, but only a b ...	2001	11402212
diversity of polyamine patterns in soft rot pathogens and other plant-associated members of the enterobacteriaceae.	polyamine profiles of 91 pectolytic and other plant-associated strains from 30 taxa of the enterobacteriaceae were obtained by gradient high performance liquid chromatography (hplc). pectobacterium carotovorum, basonym erwinia carotovora, contained a high amount of putrescine and less diaminopropane. diaminopropane was absent in pectobacterium chrysanthemi, basonym e. chrysanthemi, whereas cadaverine was present in addition to the major compound putrescine. this chemotaxonomic difference reflect ...	2001	11403399
indole can act as an extracellular signal in escherichia coli.	previous work has shown that lacz fusions to the cysk, astd, tnab, and gabt genes in escherichia coli are activated by self-produced extracellular signals. using a combination of ethyl acetate extraction, reversed-phase c(18) chromatography, and thin-layer chromatography, we have purified an extracellular activating signal from e. coli supernatants. mass spectrometry revealed a molecule with an m/z peak of 117, consistent with indole. nuclear magnetic resonance analysis of the purified e. coli f ...	2001	11418561
exo-arabinanase of penicillium chrysogenum able to release arabinobiose from alpha-1,5-l-arabinan.	an exo-arabinanase, designated abnx, was purified from a culture filtrate of penicillium chrysogenum 31b by ammonium sulfate precipitation, anion-exchange chromatography, and hydrophobic chromatography. abnx had an apparent molecular mass of 47 kda. the enzyme released only arabinobiose from the nonreducing terminus of alpha-1,5-l-arabinan and showed no activity towards p-nitrophenyl-alpha-l-arabinofuranoside and alpha-1,5-l-arabinofuranobiose. abnx is the first enzyme with this mode of action.	2001	11425761
novel topology of bfpe, a cytoplasmic membrane protein required for type iv fimbrial biogenesis in enteropathogenic escherichia coli.	enteropathogenic escherichia coli (epec) produces the bundle-forming pilus (bfp), a type iv fimbria that has been implicated in virulence, autoaggregation, and localized adherence to epithelial cells. the bfpe gene is one of a cluster of bfp genes previously shown to encode functions that direct bfp biosynthesis. here, we show that an epec strain carrying a nonpolar mutation in bfpe fails to autoaggregate, adhere to hep-2 cells, or form bfp, thereby demonstrating that bfpe is required for bfp bi ...	2001	11443077
nkbor, a mini-tn10-based transposon for random insertion in the chromosome of gram-negative bacteria and the rapid recovery of sequences flanking the insertion sites in escherichia coli.	we have constructed an r6k-based suicide vector that permits the random insertion of a mini-transposon named nkbor into the chromosome of gram-negative bacteria and the subsequent rapid cloning of sequences flanking the insertion site in escherichia coli. this mini-transposon contains a conditional r6k plasmid origin of replication, a kanamycin resistance gene and unique restriction sites between the is10 inverted repeats. nkbor can be propagated by replication in an e. coli strain containing th ...	2001	11446516
quenching quorum-sensing-dependent bacterial infection by an n-acyl homoserine lactonase.	bacterial cells sense their population density through a sophisticated cell-cell communication system and trigger expression of particular genes when the density reaches a threshold. this type of gene regulation, which controls diverse biological functions including virulence, is known as quorum sensing. quorum-sensing signals, such as acyl-homoserine lactones (ahls), are the essential components of the communication system. ahls regulate virulence gene expression in a range of plant and animal ...	2001	11459062
carbon limitation induces sigma(s)-dependent gene expression in pseudomonas fluorescens in soil.	recent studies employing reporter gene technology indicate that the availabilities of the major nutrients nitrogen, phosphate, and iron to pseudomonas are not severely limited in bulk soil. indirect evidence has pointed to carbon limitation as a severe nutritional stress in this environment. we show that a plasmid (pgm115)-borne transcriptional fusion between the sigma(s)-dependent escherichia coli promoter p(fic) and lacz functions as a reliable reporter for carbon availability in pseudomonas f ...	2001	11472905
assessment of the genetic diversity among strains of xanthomonas cynarae by randomly amplified polymorphic dna analysis and development of specific characterized amplified regions for the rapid identification of x. cynarae.	the randomly amplified polymorphic dna (rapd) method was used to investigate the genetic diversity in xanthomonas cynarae, which causes bacterial bract spot disease of artichoke. this rapd analysis was also intended to identify molecular markers characteristic of this species, in order to develop pcr-based markers which can be used to detect this pathogenic bacterium in artichoke fields. among the 340 rapd primers tested, 40 were selected on their ability to produce reproducible and reliable fin ...	2001	11472907
mutations in the drosophila dtak1 gene reveal a conserved function for mapkkks in the control of rel/nf-kappab-dependent innate immune responses.	in mammals, tak1, a mapkkk kinase, is implicated in multiple signaling processes, including the regulation of nf-kappab activity via the il1-r/tlr pathways. tak1 function has largely been studied in cultured cells, and its in vivo function is not fully understood. we have isolated null mutations in the drosophila dtak1 gene that encodes dtak1, a homolog of tak1. dtak1 mutant flies are viable and fertile, but they do not produce antibacterial peptides and are highly susceptible to gram-negative b ...	2001	11485985
haemodynamic effects of the bacterial quorum sensing signal molecule, n-(3-oxododecanoyl)-l-homoserine lactone, in conscious, normal and endotoxaemic rats.	n-acylhomoserine lactones (ahls) are small, diffusible signalling molecules, employed by gram-negative bacteria to coordinate gene expression with cell population density. recent in vitro findings indicate that ahls may function as virulence determinants per se, through modification of cytokine production by eukaryotic cells, and by stimulating the relaxation of blood vessels. in the present study, we assessed the influence of ahls on cardiovascular function in conscious rats, and draw attention ...	2001	11487515
global regulators expa (gaca) and kdgr modulate extracellular enzyme gene expression through the rsma-rsmb system in erwinia carotovora subsp. carotovora.	the production of the main virulence determinants, the extracellular plant cell wall-degrading enzymes, and hence virulence of erwinia carotovora subsp. carotovora is controlled by a complex regulatory network. one of the global regulators, the response regulator expa, a gaca homolog, is required for transcriptional activation of the extracellular enzyme genes of this soft-rot pathogen. to elucidate the mechanism of expa control as well as interactions with other regulatory systems, we isolated ...	2001	11497464
type iii secretion contributes to the pathogenesis of the soft-rot pathogen erwinia carotovora: partial characterization of the hrp gene cluster.	the virulence of soft-rot erwinia species is dependent mainly upon secreted enzymes such as pectinases, pectin lyases, and proteases that cause maceration of plant tissue. some soft-rot erwinia spp. also harbor genes homologous to the hypersensitive reaction and pathogenesis (hrp) gene cluster, encoding components of the type iii secretion system. the hrp genes are essential virulence determinants for numerous nonmacerating gram-negative plant pathogens but their role in the virulence of soft-ro ...	2001	11497468
analysis of native microflora and selection of strains antagonistic to human pathogens on fresh produce.	the native microflora of three types of produce (green bell peppers, romaine lettuce, and prepeeled baby carrots) and two types of sprouting seeds (alfalfa and clover) were investigated. aerobic plate count (apc) for each produce or seed type as determined on pseudomonas agar f (paf) with incubation at 28 degrees c was in the range of 4 to 7 log cfu per g of tissue or seed. there was no significant difference (p > or = 0.05) in apc when the determinations were made with three agar media includin ...	2001	11510644
dna microarray-based identification of genes controlled by autoinducer 2-stimulated quorum sensing in escherichia coli.	bacterial cell-to-cell communication facilitates coordinated expression of specific genes in a growth rate-ii and cell density-dependent manner, a process known as quorum sensing. while the discovery of a diffusible escherichia coli signaling pheromone, termed autoinducer 2 (ai-2), has been made along with several quorum sensing genes, the overall number and coordination of genes controlled by quorum sensing through the ai-2 signal has not been studied systematically. we investigated global chan ...	2001	11514505
enhanced disease resistance conferred by expression of an antimicrobial magainin analog in transgenic tobacco.	magainins are a group of short peptides originally isolated from frog skin and thought to function as a natural defense mechanism against infection due to their antimicrobial properties. the engineered magainin analog peptide myp30 was found to inhibit spore germination of the oomycete, peronospora tabacina (adam) in vitro, and the growth of a bacterial pathogen erwinia carotovora subsp. carotovora (jones). transgenic tobacco (nicotiana tabacum l.) plants expressing myp30 were evaluated for resi ...	2001	11525522
control of bacterial motility by environmental factors in polarly flagellated and peritrichous bacteria isolated from lake baikal.	despite numerous studies on bacterial motility, little is known about the regulation of this process by environmental factors in natural isolates. in this study we investigated the control of bacterial motility in response to environmental parameters in two strains isolated from the natural habitat of lake baikal. morphological characterization, carbon source utilization, fermentation analysis, and sequence comparison of 16s rrna genes showed that these strains belong to two distinct genera, i.e ...	2001	11525977
cosecretion of chaperones and low-molecular-size medium additives increases the yield of recombinant disulfide-bridged proteins.	attempts were made to engineer the periplasm of escherichia coli to an expression compartment of heterologous proteins in their native conformation. as a first approach the low-molecular-size additive l-arginine and the redox compound glutathione (gsh) were added to the culture medium. addition of 0.4 m l-arginine and 5 mm reduced gsh increased the yield of a native tissue-type plasminogen activator variant (rpa), consisting of the kringle-2 and the protease domain, and a single-chain antibody f ...	2001	11525996
rapid identification and differentiation of the soft rot erwinias by 16s-23s intergenic transcribed spacer-pcr and restriction fragment length polymorphism analyses.	current identification methods for the soft rot erwinias are both imprecise and time-consuming. we have used the 16s-23s rrna intergenic transcribed spacer (its) to aid in their identification. analysis by its-pcr and its-restriction fragment length polymorphism was found to be a simple, precise, and rapid method compared to current molecular and phenotypic techniques. the its was amplified from erwinia and other genera using universal pcr primers. after pcr, the banding patterns generated allow ...	2001	11526007
gly gene cloning and expression and purification of glycinecin a, a bacteriocin produced by xanthomonas campestris pv. glycines 8ra.	glycinecin a, a bacteriocin produced by xanthomonas campestris pv. glycines, inhibits the growth of x. campestris pv. vesicatoria. we have cloned and expressed the genes encoding glycinecin a in escherichia coli. recombinant glycinecin a was purified from cell extracts by ammonium sulfate precipitation followed by chromatography on q-sepharose, mono q (ion exchange), and size exclusion columns. purified glycinecin a is composed of two polypeptides, is active over a wide ph range (6 to 9), and is ...	2001	11526012
detection of methanotroph diversity on roots of submerged rice plants by molecular retrieval of pmoa, mmox, mxaf, and 16s rrna and ribosomal dna, including pmoa-based terminal restriction fragment length polymorphism profiling.	the diversity of methanotrophic bacteria associated with roots of submerged rice plants was assessed using cultivation-independent techniques. the research focused mainly on the retrieval of pmoa, which encodes the alpha subunit of the particulate methane monooxygenase. a novel methanotroph-specific community-profiling method was established using the terminal restriction fragment length polymorphism (t-rflp) technique. the t-rflp profiles clearly revealed a more complex root-associated methanot ...	2001	11526021
the emerging periplasm-localized subclass of aroq chorismate mutases, exemplified by those from salmonella typhimurium and pseudomonas aeruginosa.	chorismate mutases of the aroq homology class are widespread in the bacteria and the archaea. many of these exist as domains that are fused with other aromatic-pathway catalytic domains. among the monofunctional aroq proteins, that from erwinia herbicola was previously shown to have a cleavable signal peptide and located in the periplasmic compartment. whether or not this might be unique to e. herbicola was unknown.	2001	11532214
sdia of salmonella enterica is a luxr homolog that detects mixed microbial communities.	proteins of the luxr family detect the presence of n-acylhomoserine lactones (ahls) and regulate transcription accordingly. when ahls are synthesized by the same species that detects them, the system allows a bacterium to measure the population density of its own species, a phenomenon known as quorum sensing. the sdia genes of escherichia coli and salmonella enterica serovar typhimurium are predicted to encode luxr homologs. however, these species do not appear to synthesize ahls or any other mo ...	2001	11544237
transgenic plants producing the bacterial pheromone n-acyl-homoserine lactone exhibit enhanced resistance to the bacterial phytopathogen erwinia carotovora.	bacterial pheromones, mainly different homoserine lactones, are central to a number of bacterial signaling processes, including those involved in plant pathogenicity. we previously demonstrated that n-oxoacyl-homoserine lactone (ohl) is essential for quorum sensing in the soft-rot phytopathogen erwinia carotovora. in this pathogen, ohl controls the coordinate activation of genes encoding the main virulence determinants, extracellular plant cell wall degrading enzymes (pcwdes), in a cell density- ...	2001	11551068
salicylic acid and ethylene pathways are differentially activated in melon cotyledons by active or heat-denatured cellulase from trichoderma longibrachiatum.	infiltration of cellulase (ec 3.2.1.4) from trichoderma longibrachiatum into melon (cucumis melo) cotyledons induced several key defense mechanisms and hypersensitive reaction-like symptoms. an oxidative burst was observed 3 hours after treatment and was followed by activation of ethylene and salicylic acid (sa) signaling pathways leading to marked induction of peroxidase and chitinase activities. the treatment of cotyledons by heat-denatured cellulase also led to some induction of peroxidase an ...	2001	11553761
a conserved genetic module that encodes the major virion components in both the coliphage t4 and the marine cyanophage s-pm2.	sequence analysis of a 10-kb region of the genome of the marine cyanomyovirus s-pm2 reveals a homology to coliphage t4 that extends as a contiguous block from gene (g)18 to g23. the order of the s-pm2 genes in this region is similar to that of t4, but there are insertions and deletions of small orfs of unknown function. in t4, g18 codes for the tail sheath, g19, the tail tube, g20, the head portal protein, g21, the prohead core protein, g22, a scaffolding protein, and g23, the major capsid prote ...	2001	11553768
rpos-dependent transcriptional control of spre: regulatory feedback loop.	the stationary-phase response exhibited by escherichia coli upon nutrient starvation is mainly induced by a decrease of the clpxp-dependent degradation of the alternate primary sigma factor rpos. although it is known that the specific regulation of this proteolysis is exercised by the orphan response regulator spre, it remains unclear how spre's activity is regulated in vivo. previous studies have demonstrated that the cellular content of spre itself is paradoxically increased in stationary-phas ...	2001	11566997
regulatory interactions of csr components: the rna binding protein csra activates csrb transcription in escherichia coli.	the global regulator csra (carbon storage regulator) of escherichia coli is a small rna binding protein that represses various metabolic pathways and processes that are induced in the stationary phase of growth, while it activates certain exponential phase functions. both repression and activation by csra involve posttranscriptional mechanisms, in which csra binding to mrna leads to decreased or increased transcript stability, respectively. csra also binds to a small untranslated rna, csrb, form ...	2001	11567002
bulk and rhizosphere soil bacterial communities studied by denaturing gradient gel electrophoresis: plant-dependent enrichment and seasonal shifts revealed.	the bacterial rhizosphere communities of three host plants of the pathogenic fungus verticillium dahliae, field-grown strawberry (fragaria ananassa duch.), oilseed rape (brassica napus l.), and potato (solanum tuberosum l.), were analyzed. we aimed to determine the degree to which the rhizosphere effect is plant dependent and whether this effect would be increased by growing the same crops in two consecutive years. rhizosphere or soil samples were taken five times over the vegetation periods. to ...	2001	11571180
survival of salmonellae on and in tomato plants from the time of inoculation at flowering and early stages of fruit development through fruit ripening.	the fate of salmonellae applied to tomato plants was investigated. five salmonella serotypes were used to inoculate tomato plants before and after fruits set, either by injecting stems with inoculum or brushing flowers with it. ripe tomato fruits were subjected to microbiological analysis. peptone wash water, homogenates of stem scar tissues, and homogenates of fruit pulp were serially diluted and plated on bismuth sulfite agar before and after enrichment. presumptive salmonella colonies were co ...	2001	11571182
dna inversion in the tail fiber gene alters the host range specificity of carotovoricin er, a phage-tail-like bacteriocin of phytopathogenic erwinia carotovora subsp. carotovora er.	carotovoricin er is a phage-tail-like bacteriocin produced by erwinia carotovora subsp. carotovora strain er, a causative agent for soft rot disease in plants. here we studied binding and killing spectra of carotovoricin er preparations for various strains of the bacterium (strains 645ar, ec-2, n786, and p7) and found that the preparations contain two types of carotovoricin er with different host specificities; carotovoricin era possessing a tail fiber protein of 68 kda killed strains 645ar and ...	2001	11591670
isolation and characterisation of the major outer membrane protein of erwinia carotovora.	the purified major outer membrane protein (37275 da) from the psychrotrophic phytopathogen erwinia carotovora mfcl0 was structurally characterised by maldi-tof mass spectrometry, n-terminal microsequencing and dna sequence determinations, and secondary structure prediction analyses. the deduced amino acid sequence showed 76% and 72% of similarities with the serratia marcescens and escherichia coli ompa proteins respectively. dendrogram analysis allowed to point out that e. carotovora is close to ...	2001	11597348
the global posttranscriptional regulator rsma modulates production of virulence determinants and n-acylhomoserine lactones in pseudomonas aeruginosa.	posttranscriptional control is known to contribute to the regulation of secondary metabolism and virulence determinants in certain gram-negative bacteria. here we report the isolation of a pseudomonas aeruginosa gene which encodes a global translational regulatory protein, rsma (regulator of secondary metabolites). overexpression of rsma resulted in a substantial reduction in the levels of extracellular products, including protease, elastase, and staphylolytic (lasa protease) activity as well as ...	2001	11673439
colicin a immunity protein interacts with the hydrophobic helical hairpin of the colicin a channel domain in the escherichia coli inner membrane.	the colicin a pore-forming domain (pfcola) was fused to a bacterial signal peptide (sp-pfcola). this was inserted into the escherichia coli inner membrane in functional form and could be coimmunoprecipitated with epitope-tagged immunity protein (epcai). we constructed a series of fusion proteins in which various numbers of sp-pfcola alpha-helices were fused to alkaline phosphatase (ap). we showed that a fusion protein made up of the hydrophobic alpha-helices 8 and 9 of sp-pfcola fused to ap was ...	2001	11673448
prevention and management of antineoplastic-induced hypersensitivity reactions.	acute hypersensitivity reactions (hsrs) are an unpredictable and potentially catastrophic complication of treatment with chemotherapeutic agents. reactions may affect any organ system in the body and range widely in severity from mild pruritus to systemic anaphylaxis. certain classes of chemotherapeutic agents, such as the taxanes, platinum compounds, asparaginases, and epipodophyllotoxins are commonly associated with hsrs. the clinical characteristics of these high risk agents with respect to h ...	2001	11676304
structural requirements of endopolygalacturonase for the interaction with pgip (polygalacturonase-inhibiting protein).	to invade a plant tissue, phytopathogenic fungi produce several cell wall-degrading enzymes; among them, endopolygalacturonase (pg) catalyzes the fragmentation and solubilization of homogalacturonan. polygalacturonase-inhibiting proteins (pgips), found in the cell wall of many plants, counteract fungal pgs by forming specific complexes with them. we report the crystal structure at 1.73 a resolution of pg from the phytopathogenic fungus fusarium moniliforme (fmpg). the structure of fmpg was usefu ...	2001	11687632
the global regulators gaca and sigma(s) form part of a cascade that controls alginate production in azotobacter vinelandii.	transcription of the azotobacter vinelandii algd gene, which encodes gdp-mannose dehydrogenase (the rate-limiting enzyme of alginate synthesis), starts from three sites: p1, p2, and p3. the sensor kinase gacs, a member of the two-component regulatory system, is required for transcription of algd from its three sites during the stationary phase. here we show that algd is expressed constitutively throughout the growth cycle from the p2 and p3 sites and that transcription from p1 started at the tra ...	2001	11698366
organization of genes controlling disease resistance in the potato genome.	nineteen single dominant genes (r genes) for resistance to viruses, nematodes, and fungi have been positioned on the molecular map of potato using dna markers. fourteen of those genes are located in five "hotspots" for resistance in the potato genome. quantitative trait loci (qtl) for resistance to late blight caused by the oomycete phytophthora infestans, to tuber rot caused by the bacterium erwinia carotovora ssp. atroseptica, and to root cyst nematodes have been identified on all 12 potato ch ...	2001	11701860
expression of an antimicrobial peptide via the chloroplast genome to control phytopathogenic bacteria and fungi.	the antimicrobial peptide msi-99, an analog of magainin 2, was expressed via the chloroplast genome to obtain high levels of expression in transgenic tobacco (nicotiana tabacum var. petit havana) plants. polymerase chain reaction products and southern blots confirmed integration of msi-99 into the chloroplast genome and achievement of homoplasmy, whereas northern blots confirmed transcription. contrary to previous predictions, accumulation of msi-99 in transgenic chloroplasts did not affect norm ...	2001	11706168
proteins induced during adaptation of acetobacter aceti to high acetate concentrations.	as a typical product of microbial metabolism, the weak acid acetate is well known for its cytotoxic effects. in contrast to most other microbes, the so-called acetic acid bacteria can acquire significant resistance to high acetate concentrations when properly adapted to such hostile conditions. to characterize the molecular events that are associated with this adaptation, we analyzed global protein expression levels during adaptation of acetobacter aceti by two-dimensional gel electrophoresis. a ...	2001	11722895
characterization of enterocoliticin, a phage tail-like bacteriocin, and its effect on pathogenic yersinia enterocolitica strains.	yersinia enterocolitica 29930 (biogroup 1a; serogroup o:7,8) produces a bacteriocin, designated enterocoliticin, that shows inhibitory activity against enteropathogenic strains of y. enterocolitica belonging to serogroups o:3, o:5,27 and o:9. enterocoliticin was purified, and electron micrographs of enterocoliticin preparations revealed the presence of phage tail-like particles. the particles did not contain nucleic acids and showed contraction upon contact with susceptible bacteria. enterocolit ...	2001	11722917
visualization of n-acylhomoserine lactone-mediated cell-cell communication between bacteria colonizing the tomato rhizosphere.	given that a large proportion of the bacteria colonizing the roots of plants is capable of producing n-acyl-l-homoserine lactone (ahl) molecules, it appears likely that these bacterial pheromones may serve as signals for communication between cells of different species. in this study, we have developed and characterized novel gfp-based monitor strains that allow in situ visualization of ahl-mediated communication between individual cells in the plant rhizosphere. for this purpose, three gfp-base ...	2001	11722933
overexpresssion of a legionella pneumophila homologue of the e. coli regulator csra affects cell size, flagellation, and pigmentation.	legionella pneumophila is an inhabitant of the aquatic environment and the causative agent of a bacterial pneumonia. we identified the presence of an l. pneumophila homologue of csra of e. coli and rsma of erwinia carotovora, genes which regulate gene expression by destabilising mrna and which have been shown to relate to environmental fitness and pathogenicity. the legionella csra was able to complement a csra-negative mutant of e. coli. overproduction of csra in l. pneumophila lead to a reduct ...	2001	11727819
halogenated furanones from the red alga, delisea pulchra, inhibit carbapenem antibiotic synthesis and exoenzyme virulence factor production in the phytopathogen erwinia carotovora.	the plant pathogen erwinia carotovora regulates expression of virulence factors and antibiotic production via an n-3-oxohexanoyl-l-homoserine lactone (3-oxo-c6-hsl) dependent quorum sensing mechanism. the marine alga delisea pulchra produces halogenated furanones known to antagonise 3-oxo-c6-hsl activity. we have tested the effects of a halogenated furanone on the production of carbapenem, cellulase and protease in e. carotovora. despite differences in the regulatory mechanisms controlling carba ...	2001	11728727
optimization of fermentation reaction conditions for preparation of pate enzyme by erwinia carotovora ifo3830 by tfccrd method.	the fermentation conditions for preparation of polygalacturonic acid transeliminase (pate) enzyme by erwinia carotovora ifo3830 were optimized for seed ratio, vibration rate, and temperature by the tfccrd method. the results indicated that the optimum fermentation conditions for e. carotovora ifo 3830 were that seed ratio, vibration rate, and temperature were 5% v/v, 113 min(-1), and 29 degrees c, respectively.	2001	11735434
enteric bacteria counteract lipopolysaccharide induction of antimicrobial peptide genes.	the humoral immunity of drosophila involves the production of antimicrobial peptides, which are induced by evolutionary conserved microbial molecules, like lps. by using drosophila mbn-2 cells, we found that live bacteria, including e. coli, salmonella typhimurium, erwinia carotovora, and pseudomonas aeruginosa, prevented lps from inducing antimicrobial peptide genes, while micrococcus luteus and streptococcus equi did not. the inhibitory effect was seen at bacterial levels from 20 per mbn-2 cel ...	2001	11739510
dissimilatory fe(iii) and mn(iv) reduction by shewanella putrefaciens requires fere, a homolog of the pule (gspe) type ii protein secretion gene.	shewanella putrefaciens strain 200 respires anaerobically on a wide range of compounds as the sole terminal electron acceptor, including ferric iron [fe(iii)] and manganese oxide [mn(iv)]. previous studies demonstrated that a 23.3-kb s. putrefaciens wild-type dna fragment conferred metal reduction capability to a set of respiratory mutants with impaired fe(iii) and mn(iv) reduction activities (t. dichristina and e. delong, j. bacteriol. 176:1468-1474, 1994). in the present study, the smallest co ...	2002	11741854
betawrap: successful prediction of parallel beta -helices from primary sequence reveals an association with many microbial pathogens.	the amino acid sequence rules that specify beta-sheet structure in proteins remain obscure. a subclass of beta-sheet proteins, parallel beta-helices, represent a processive folding of the chain into an elongated topologically simpler fold than globular beta-sheets. in this paper, we present a computational approach that predicts the right-handed parallel beta-helix supersecondary structural motif in primary amino acid sequences by using beta-strand interactions learned from non-beta-helix struct ...	2001	11752429
homology of escherichia coli r773 arsa, arsb, and arsc genes in arsenic-resistant bacteria isolated from raw sewage and arsenic-enriched creek waters.	the occurrence and diversity of the escherichia coli r773 ars operon were investigated among arsenic-resistant enteric and nonenteric bacteria isolated from raw sewage and arsenic-enriched creek waters. selected isolates from each creek location were screened for ars genes by colony hybridization and pcr. the occurrence of arsa, arsb, and arsc determined by low-stringency colony hybridization (31 to 53% estimated mismatch) was 81, 87, and 86%, respectively, for 84 bacteria isolated on arsenate- ...	2002	11772637
[isolation and preliminary characterization of cryptic plasmids from erwinia carotovora].	of the fifty-two erwinia carotovora strains studied, sixteen were found to contain extrachromosomal dna (plasmids) from 2.5 to 129 kbp in size. some e. carotovora strains bore two to five different plasmids. experiments showed that the cryptic plasmids of erwinia are not responsible for their resistance to antibiotics and are not involved in the synthesis of macromolecular colicin-like carotovoricins. at the same time, one of the e. carotovora strains, 13a, augmented the production of carotovori ...	2001	11785137
effect of high oxygen modified atmosphere packaging on microbial growth and sensorial qualities of fresh-cut produce.	the application of high oxygen atmospheres (hoa) (i.e. > 70% o2) for packaging ready-to-eat vegetables was evaluated as an alternative technique for low o2 equilibrium modified atmosphere (ema) packaging (3% o2-5% co2-balance n2) for respiring products. comparative experiments between both techniques were performed in-vitro and in-vivo. typical spoilage causing microorganisms (pseudomonas fluorescens, candida lambica), the moulds botrytis cinerea, aspergillus flavus and the opportunistic psychro ...	2001	11789938
mob psychology.		2002	11807045
regulatory rna as mediator in gaca/rsma-dependent global control of exoproduct formation in pseudomonas fluorescens cha0.	in pseudomonas fluorescens cha0, an antagonist of root-pathogenic fungi, the gacs/gaca two-component system tightly controls the expression of antifungal secondary metabolites and exoenzymes at a posttranscriptional level, involving the rna-binding protein and global regulator of secondary metabolism rsma. this protein was purified from p. fluorescens, and rna bound to it was converted to cdna, which served as a probe to isolate the corresponding chromosomal locus, rsmz. this gene encoded a regu ...	2002	11807065
nonenzymatic turnover of an erwinia carotovora quorum-sensing signaling molecule.	the production of virulence factors and carbapenem antibiotic in the phytopathogen erwinia carotovora is under the control of quorum sensing. the quorum-sensing signaling molecule, n-(3-oxohexanoyl)-l-homoserine lactone (ohhl), accumulates in log-phase culture supernatants of e. carotovora but diminishes in concentration during the stationary phase. in this study, we show that the diminution in ohhl was not due to sequestration of the ligand by the cells, although some partitioning did occur. ra ...	2002	11807077
quorum-sensing signals and quorum-sensing genes in burkholderia vietnamiensis.	acyl-homoserine lactone (acyl-hsl) quorum sensing is common to many proteobacteria including a clinical isolate of burkholderia cepacia. the b. cepacia isolate produces low levels of octanoyl-hsl. we have examined an environmental isolate of burkholderia vietnamiensis. this isolate produced several acyl-hsls. the most abundant species was decanoyl-hsl. decanoyl-hsl in b. vietnamiensis cultures reached concentrations in excess of 20 microm. we isolated a b. vietnamiensis dna fragment containing a ...	2002	11807080
efficient insertion mutagenesis strategy for bacterial genomes involving electroporation of in vitro-assembled dna transposition complexes of bacteriophage mu.	an efficient insertion mutagenesis strategy for bacterial genomes based on the phage mu dna transposition reaction was developed. incubation of mua transposase protein with artificial mini-mu transposon dna in the absence of divalent cations in vitro resulted in stable but inactive mu dna transposition complexes, or transpososomes. following delivery into bacterial cells by electroporation, the complexes were activated for dna transposition chemistry after encountering divalent metal ions within ...	2002	11823210
genotyping of bacteria belonging to the former erwinia genus by pcr-rflp analysis of a reca gene fragment.	genotypic characterization, based on the analysis of restriction fragment length polymorphism of the reca gene fragment pcr product (reca pcr-rflp), was performed on members of the former erwinia genus. pcr primers deduced from published reca gene sequences of erwinia carotovora allowed the amplification of an approximately 730 bp dna fragment from each of the 19 erwinia species tested. amplified reca fragments were compared using rflp analysis with four endonucleases (alui, hinfi, tasi and tru1 ...	2002	11832521
manipulation of strawberry fruit softening by antisense expression of a pectate lyase gene.	strawberry (fragaria x ananassa, duch., cv chandler) is a soft fruit with a short postharvest life, mainly due to a rapid lost of firm texture. to control the strawberry fruit softening, we obtained transgenic plants that incorporate an antisense sequence of a strawberry pectate lyase gene under the control of the 35s promoter. forty-one independent transgenic lines (apel lines) were obtained, propagated in the greenhouse for agronomical analysis, and compared with control plants, non-transforme ...	2002	11842178
constitutive expression of a single antimicrobial peptide can restore wild-type resistance to infection in immunodeficient drosophila mutants.	one of the characteristics of the host defense of insects is the rapid synthesis of a variety of potent antibacterial and antifungal peptides. to date, seven types of inducible antimicrobial peptides (amps) have been characterized in drosophila. the importance of these peptides in host defense is supported by the observation that flies deficient for the toll or immune deficiency (imd) pathway, which affects amp gene expression, are extremely susceptible to microbial infection. here we have devel ...	2002	11854512
effects of t4 lysozyme release from transgenic potato roots on bacterial rhizosphere communities are negligible relative to natural factors.	rhizosphere bacterial communities of two transgenic potato lines which produce t4 lysozyme for protection against bacterial infections were analyzed in comparison to communities of wild-type plants and transgenic controls not harboring the lysozyme gene. rhizosphere samples were taken from young, flowering, and senescent plants at two field sites in three consecutive years. the communities were characterized in a polyphasic approach. cultivation-dependent methods included heterotrophic plate cou ...	2002	11872484
regulation of the expression of prtw::gusa fusions in erwinia carotovora subsp. carotovora.	erwinia carotovora subsp. carotovora, a gram-negative phytopathogenic bacterium, secretes an extracellular metalloprotease, prtw. previous results demonstrated that protease activity is necessary for the normal progression of disease symptoms caused by this bacterium. the present study revealed that the prtw gene constitutes an independent transcriptional unit. it is demonstrated that introduction of the prtw(+) plasmid in trans into the prtw(-) mutant restores the protease activity in this stra ...	2002	11882719
altered lignin structure and resistance to pathogens in spi 2-expressing tobacco plants.	the physiological role of the norway spruce [ picea abies (l.) karst.] spi 2 gene, encoding a defense-related cationic peroxidase was examined in transgenic tobacco (nicotiana tabacum l.). expression of spi 2, under control of the 35s promoter, in tobacco plants resulted in higher total peroxidase activities. the phenotype of the spi 2-transformed lines was normal. the spi 2-transformed lines displayed lignin levels similar to levels in the control line, but with some alteration in lignin histoc ...	2002	11882939
[temperate bacteriophage zf40 of erwinia carotovora: phage particle structure and dna restriction analysis].	structural organization of the temperate bacteriophage zf40 of erwinia carotovora was studied. phage zf40 proved to be a typical member of the myoviridae family (morphotype a1). phage particles consist of an isometric head 58.3 nm in diameter and a contractile 86.3-nm-long tail with a complex basal plate and short tail fibers (31.5 nm). phage tail sheath, a truncated cone in shape, is characterized by specific packaging of structural subunits. the zf40 phage genome is 45.8 kb in size, as determi ...	2002	11910811
[study of erwinia carotovora phage resistance with the use of temperate bacteriophage zf40].	the causes of the unique phage resistance of the pectinolytic phytopathogenic strains of erwinia carotovora were studied with the use of temperate bacteriophage zf40. it was shown that, in these bacteria, the bacteriophage-cell interaction can be substantially blocked at the adsorption level. an adequate indicator for studying the temperate bacteriophages of erwinias was developed on the basis of mutants resistant to macromolecular bacteriocins. various restriction-modification systems, which in ...	2002	11910812
the extracellular transport signal of the vibrio cholerae endochitinase (chia) is a structural motif located between amino acids 75 and 555.	chia, an 88-kda endochitinase encoded by the chia gene of the gram-negative enteropathogen vibrio cholerae, is secreted via the eps-encoded main terminal branch of the general secretory pathway (gsp), a mechanism which also transports cholera toxin. to localize the extracellular transport signal of chia that initiates transport of the protein through the gsp, a chimera comprised of chia fused at the n terminus with the maltose-binding protein (male) of escherichia coli and fused at the c terminu ...	2002	11914354
application of amplified fragment length polymorphism fingerprinting for taxonomy and identification of the soft rot bacteria erwinia carotovora and erwinia chrysanthemi.	the soft rot bacteria erwinia carotovora and erwinia chrysanthemi are important pathogens of potato and other crops. however, the taxonomy of these pathogens, particularly at subspecies level, is unclear. an investigation using amplified fragment length polymorphism (aflp) fingerprinting was undertaken to determine the taxonomic relationships within this group based on their genetic relatedness. following cluster analysis on the similarity matrices derived from the aflp gels, four clusters (clus ...	2002	11916661
the ybit gene of erwinia chrysanthemi codes for a putative abc transporter and is involved in competitiveness against endophytic bacteria during infection.	we investigated the role in bacterial infection of a putative abc transporter, designated ybit, of erwinia chrysanthemi ac4150. the deduced sequence of this gene showed amino acid sequence similarity with other putative abc transporters of gram-negative bacteria, such as escherichia coli and pseudomonas aeruginosa, as well as structural similarity with proteins of streptomyces spp. involved in resistance to macrolide antibiotics. the gene contiguous to ybit, designated as pab (putative antibioti ...	2002	11916677