| analytical validation of a microplate reader-based method for the therapeutic drug monitoring of l-asparaginase in human serum. | the enzyme l-asparaginase (asnase), which hydrolyzes l-asparagine (l-asn) to ammonia and l-aspartic acid (l-asp), is commonly used for remission induction in acute lymphoblastic leukemia. to correlate asnase activity with l-asn reduction in human serum, sensitive methods for the determination of asnase activity are required. using l-aspartic beta-hydroxamate (aha) as substrate we developed a sensitive plate reader-based method for the quantification of asnase derived from escherichia coli and er ... | 2002 | 12381370 |
| coupling of iron assimilation and pectinolysis in erwinia chrysanthemi 3937. | two major virulence determinants of the plant-pathogenic enterobacterium erwinia chrysanthemi strain 3937 are the production of pectate lyase enzymes that degrade plant cell walls and expression of two high-affinity iron uptake systems mediated by two structurally unrelated siderophores, chrysobactin and achromobactin. low iron availability is a signal that triggers transcription of the genes encoding pectate lyases peld and pele as well as that of genes involved in iron transport. this metallor ... | 2002 | 12423024 |
| direct structure determination using residual dipolar couplings: reaction-site conformation of methionine sulfoxide reductase in solution. | residual dipolar couplings (rdc) from partially aligned molecules provide long-range structural data and are thus particularly well adapted to rapid structure validation or protein fold recognition. extensive measurements in two alignment media can also provide precise de novo structure from rdc alone. we have applied a novel combination of these approaches to the study of methionine sulfoxide reductase (msra) from erwinia chrysanthemi, a 27 kda enzyme essential for repairing oxidative stress da ... | 2002 | 12431100 |
| cloning and characterization of the glycogen branching enzyme gene existing in tandem with the glycogen debranching enzyme from pectobacterium chrysanthemi py35. | the glycogen branching enzyme gene (glgb) from pectobacterium chrysanthemi py35 was cloned, sequenced, and expressed in escherichia coli. the glgb gene consisted of an open reading frame of 2196bp encoding a protein of 731 amino acids (calculated molecular weight of 83,859da). the glgb gene is upstream of glgx and the orf starts the atg initiation codon and ends with the tga stop codon at 2bp upstream of glgx. the enzyme was 43-69% sequence identical with other glycogen branching enzymes. the en ... | 2003 | 12480526 |
| atomic resolution structure of erwinia chrysanthemi l-asparaginase. | an x-ray structure of l-asparaginase from erwinia chrysanthemi (era) has been refined at 1 a resolution to an r factor of below 0.1, using data collected on a synchrotron source. with four molecules of the enzyme consisting of 327 amino acids each, this crystal contains one of the largest asymmetric units of a protein refined to date at atomic resolution. previously, structures of era and of related enzymes from other bacterial sources have been refined at resolutions not exceeding 1.7 a; thus, ... | 2003 | 12499544 |
| nitric oxide contributes to induction of innate immune responses to gram-negative bacteria in drosophila. | studies in mammals uncovered important signaling roles of nitric oxide (no), and contributions to innate immunity. suggestions of conservation led us to explore the involvement of no in drosophila innate immunity. inhibition of nitric oxide synthase (nos) increased larval sensitivity to gram-negative bacterial infection, and abrogated induction of the antimicrobial peptide diptericin. nos was up-regulated after infection. antimicrobial peptide reporters revealed that no triggered an immune respo ... | 2003 | 12514104 |
| asap, a systematic annotation package for community analysis of genomes. | asap (a systematic annotation package for community analysis of genomes) is a relational database and web interface developed to store, update and distribute genome sequence data and functional characterization (https://asap.ahabs.wisc.edu/annotation/php/asap1.htm). asap facilitates ongoing community annotation of genomes and tracking of information as genome projects move from preliminary data collection through post-sequencing functional analysis. the asap database includes multiple genome seq ... | 2003 | 12519969 |
| plasmids spread very fast in heterogeneous bacterial communities. | conjugative plasmids can mediate gene transfer between bacterial taxa in diverse environments. the ability to donate the f-type conjugative plasmid r1 greatly varies among enteric bacteria due to the interaction of the system that represses sex-pili formations (products of finop) of plasmids already harbored by a bacterial strain with those of the r1 plasmid. the presence of efficient donors in heterogeneous bacterial populations can accelerate plasmid transfer and can spread by several orders o ... | 2002 | 12524329 |
| characterization and implications of ca2+ binding to pectate lyase c. | ca(2+) is essential for in vitro activity of erwinia chrysanthemi pectate lyase c (pelc). crystallographic analyses of 11 pelc-ca(2+) complexes, formed at ph 4.5, 9.5, and 11.2 under varying ca(2+) concentrations, have been solved and refined at a resolution of 2.2 a. the ca(2+) site represents a new motif for ca(2+), consisting primarily of beta-turns and beta-strands. the principal differences between pelc and the pelc-ca(2+) structures at all ph values are the side-chain conformations of asp- ... | 2003 | 12540845 |
| sufc: an unorthodox cytoplasmic abc/atpase required for [fe-s] biogenesis under oxidative stress. | proteins containing [fe-s] clusters perform essential functions in all domains of life. previously, we identified the sufabcdse operon as being necessary for virulence of the plant pathogen erwinia chrysanthemi. in addition, we collected preliminary evidence that the sufabcdse operon might be involved in the assembly of [fe-s] clusters. of particular interest are the sufb, sufc and sufd genes, which are conserved among eubacteria, archaea, plants and parasites. the present study establishes sufc ... | 2003 | 12554644 |
| [type iii secretion system in se9r can recognize and secret harpin in erwinia amylovora]. | bacterial pathogens of both animals and plants use type iii secretion machines to secret virulence proteins. the signal that leads to tye type iii secretion is encoded as stem loop structure in the messenger rna. harpin, produced by erwinia anylovora is secreted via type iii secretion. erwinia carotovora se9r and erwinia amylovora belong to the same genus and they use type iii secretion machines to secret virulence proteins. we used pcr to amplify hrpn from pcpp430 which harbors hrpn gene cluste ... | 2002 | 12557554 |
| rhamnogalacturonate lyase rhie is secreted by the out system in erwinia chrysanthemi. | supernatants of rhamnose-induced erwinia chrysanthemi strain 3937 cultures contain a principal secreted protein named rhie. a rhie mutant has been found among a set of rhamnose-induced mudi1681 lacz fusions. rhie is a 62-kda protein that has rhamnogalacturonate lyase activity on rhamnogalacturonan i (rg-i). it does not require a divalent cation for its activity and has an optimal ph of 6.0. rhie expression is strongly induced in the presence of rhamnose but is also regulated by pect and crp, two ... | 2003 | 12591882 |
| topology of the erwinia chrysanthemi oligogalacturonate porin kdgm. | the erwinia chrysanthemi oligogalacturonate-specific monomeric porin, kdgm, does not present homology with any porins of known structure. a model of this protein, based on sequence similarity and the amphipathy profile, was constructed. the model depicts a beta-barrel composed of 14 antiparallel beta-strands. the accuracy of this model was tested by the chemical labelling of cysteine residues introduced by site-directed mutagenesis. the protein has seven surface-exposed loops. they are rather sm ... | 2003 | 12603200 |
| crystal structure of carbapenem synthase (carc). | the proposed biosynthetic pathway to the carbapenem antibiotics proceeds via epimerization/desaturation of a carbapenam in an unusual process catalyzed by an iron- and 2-oxoglutarate-dependent oxygenase, carc. crystal structures of carc complexed with fe(ii) and 2-oxoglutarate reveal it to be hexameric (space group c2221), consistent with solution studies. carc monomers contain a double-stranded beta-helix core that supports ligands binding a single fe(ii) to which 2-oxoglutarate complexes in a ... | 2003 | 12611886 |
| a single gene that promotes interaction of a phytopathogenic bacterium with its insect vector, drosophila melanogaster. | insects are major vectors of plant and animal disease, and bacterial phytopathogens are often disseminated by flies. we have previously reported that some isolates of the phytopathogenic bacterial species erwinia carotovora infect drosophila and activate an immune response. using a genetic screen, we have now identified two genes that are required by e. carotovora to infect drosophila. one of these genes has a regulatory role whereas the other, evf, confers an infectious phenotype: its transfer ... | 2003 | 12612613 |
| sufa from erwinia chrysanthemi. characterization of a scaffold protein required for iron-sulfur cluster assembly. | sufa is a component of the recently discovered suf operon, which has been shown to play an important function in bacteria during iron-sulfur cluster biosynthesis and resistance to oxidative stress. the sufa protein from erwinia chrysanthemi, a gram-negative plant pathogen, has been purified to homogeneity and characterized. it is a homodimer with the ability to assemble rather labile [2fe-2s] and [4fe-4s] clusters as shown by mössbauer spectroscopy. these clusters can be transferred to apoprotei ... | 2003 | 12637501 |
| erwinia carotovora subsp. carotovora and erwinia-derived elicitors hrpn and peha trigger distinct but interacting defense responses and cell death in arabidopsis. | we have used an hrp-positive strain of the soft rot pathogen erwinia carotovora subsp. carotovora to elucidate plant responses to this bacterial necrotroph. purified virulence determinants, harpin (hrpn) and polygalacturonase (peha), were used as tools to facilitate this analysis. we show that hrpn elicits lesion formation in arabidopsis and tobacco and triggers systemic resistance in arabidopsis. establishment of resistance is accompanied by the expression of salicylic acid (sa)-dependent, but ... | 2003 | 12650449 |
| comparative study of regulatory mechanisms for pectinase production by erwinia carotovora subsp. carotovora and erwinia chrysanthemi. | the production of pectinase, the major virulence determinant of soft-rot erwinia species, is controlled by many regulatory factors. we focused on the major regulatory proteins, kdgr, crp, pir, and pecs, characterized mainly in e. chrysanthemi, and tested for their presence and function in the control of pectate lyase (pel) and polygalacturonase (peh) production in e. carotovora subsp. carotovora. homologues of kdgr and crp but not of pir and pecs were detected by southern blot analyses in e. car ... | 2003 | 12650454 |
| elevation of three subspecies of pectobacterium carotovorum to species level: pectobacterium atrosepticum sp. nov., pectobacterium betavasculorum sp. nov. and pectobacterium wasabiae sp. nov. | a collection of 42 strains belonging to the five subspecies of pectobacterium carotovorum (subspecies atrosepticum, betavasculorum, carotovorum, odoriferum and wasabiae) and 11 reference and type strains of biovars of pectobacterium chrysanthemi, pectobacterium cacticidum and brenneria paradisiaca were studied by dna-dna hybridization, numerical taxonomy of 120 phenotypic characteristics, serology and new phylogenetic analysis of previously reported sequences from a database of aligned 16s rdna ... | 2003 | 12710602 |
| sweet pepper ferredoxin-like protein ( pflp) gene as a novel selection marker for orchid transformation. | a novel method for selection of transgenic plants utilizing the sweet pepper ( capsicum annuum l.) ferredoxin-like protein ( pflp) gene as selection marker and erwinia carotovora as the selection agent has been developed. an expression vector containing a pflp cdna driven by a cauliflower mosaic virus 35s promoter was successfully transformed into protocorm-like bodies of oncidium orchid by agrobacterium tumefaciens and particle bombardment, respectively. erwinia carotovora was used as a selecti ... | 2003 | 12721849 |
| enhanced resistance to phytophthora infestans and alternaria solani in leaves and tubers, respectively, of potato plants with decreased activity of the plastidic atp/adp transporter. | recently, it has been reported that tubers of transgenic potato ( solanum tuberosum l.) plants with decreased activity of the plastidic atp/adp transporter (aatp1) contain less starch, despite having an increased glucose level [p. geigenberger et al. (2001) plant physiol 125:1667-1678]. the metabolic alterations correlated with enhanced resistance to the bacterium erwinia carotovora. here it is shown that transgenic potato tubers, possessing less starch yet increased glucose levels due to the ex ... | 2003 | 12721851 |
| paex, a second pectin acetylesterase of erwinia chrysanthemi 3937. | erwinia chrysanthemi causes soft-rot diseases of various plants by enzymatic degradation of the pectin in plant cell walls. pectin is a complex polysaccharide. the main chain is constituted of galacturonate residues, and some of them are modified by methyl and/or acetyl esterification. esterases are necessary to remove these modifications and, thus, to facilitate the further degradation of the polysaccharidic chain. in addition to paey, the first pectin acetylesterase identified in the e. chrysa ... | 2003 | 12730169 |
| peh production, flagellum synthesis, and virulence reduced in erwinia carotovora subsp. carotovora by mutation in a homologue of cytr. | erwinia carotovora subsp. carotovora is a causal agent of soft-rot diseases in a wide variety of plants. here, we have isolated a new regulatory factor involved in the virulence of e. carotovora subsp. carotovora by in vivo insertional mutagenesis using a transposon tn5. the gene was homologous to cytr encoding a transcriptional repressor of nucleoside uptake and catabolism genes in escherichia coli, salmonella typhimurium, and vibrio cholerae. phenotypic characterization of a nonpolar deletion ... | 2003 | 12744509 |
| [the study of erwinia carotovora bacteriocins in the nalidixic acid resistant erwinia carotovora]. | a novel approach is proposed for the study of the macromolecular bacteriocins of erwinia carotovora (mctvs). the approach lies in that the bacteriocinogeny of pectolytic erwinia is studied using a lawn of a bacterial mutant resistant to nalidixic acid, an inducer of mctvs. the high efficiency of this approach was demonstrated by studying carotovoricins in 104 different e. carotovora strains, 88% of which bear mctvs, distinguished by the morphology of zones of induced lysis on a lawn of susceptib ... | 2003 | 12751244 |
| effects of salts on the function and conformational stability of shikimate kinase. | the unfolding of shikimate kinase (sk) from erwinia chrysanthemi by urea and its subsequent refolding on dilution of the denaturing agent has been studied in detail [eur. j. biochem. 269 (2002) 2124]. comparison of the effects of urea on the enzyme with those of guanidinium chloride (gdmcl) and nacl indicated that chloride ions significantly weakened the binding of shikimate. this finding prompted a more detailed examination of the effects of salts on the structure, function and stability of the ... | 2003 | 12758146 |
| ahld, an n-acylhomoserine lactonase in arthrobacter sp., and predicted homologues in other bacteria. | quorum sensing is a signalling mechanism that controls diverse biological functions, including virulence, via n-acylhomoserine lactone (ahl) signal molecules in gram-negative bacteria. with the aim of isolating strains or enzymes capable of blocking quorum sensing by inactivating ahl, bacteria were screened for ahl degradation by their ability to utilize n-3-oxohexanoyl-l-homoserine lactone (ohhl) as the sole carbon source. among four isolates, strain ibn110, identified as arthrobacter sp., was ... | 2003 | 12777494 |
| the sweet pepper ferredoxin-like protein (pflp) conferred resistance against soft rot disease in oncidium orchid. | genetic engineering to date has not been used to introduce disease resistance genes into the orchid gene pool. the ferredoxin-like protein gene originally isolated from sweet pepper is thought to function as a natural defense against infection due to its antimicrobial properties. hence it was reasoned that introduction of this gene might produce oncidium plants resistant to erwinia carotovora, the causal agent for the soft rot disease. an expression vector containing sweet pepper ferredoxin-like ... | 2003 | 12779121 |
| inhibition and alternate substrate studies on the mechanism of carbapenam synthetase from erwinia carotovora. | the erwinia carotorova cara, carb, and carc gene products are essential for the biosynthesis of (5r)-carbapen-2-em-3-carboxylic acid, the simplest carbapenem beta-lactam antibiotic. cara (hereafter named carbapenam synthetase) has been proposed to catalyze formation of (3s,5s)-carbapenam-3-carboxylic acid from (2s,5s)-5-carboxymethyl proline based on characterization of the products of fermentation experiments in escherichia coli cells transformed with pet24a/carb and pet24a/carab, and on sequen ... | 2003 | 12820893 |
| the erwinia chrysanthemi phop-phoq operon plays an important role in growth at low ph, virulence and bacterial survival in plant tissue. | we have studied the role of acidic ph as a barrier for the colonization of the plant apoplast by erwinia chrysanthemi. a minitransposon containing a promoterless reporter gene, gus, was used for random mutagenesis of the bacterial genome. an acid-sensitive mutant, named bt119, was isolated and had the following differential features with respect to the wild-type strain: (i) inability to grow at ph </= 5.5; (ii) decreased survival at acid ph and in plant tissues; (iii) increased susceptibility to ... | 2003 | 12828634 |
| effect of mutations in the t1.5 loop of pectate lyase a from erwinia chrysanthemi ec16. | pectate lyase a (pela) is a pectate-degrading enzyme secreted by plant pathogens. pela from erwinia chrysanthemi has 61% amino-acid identity and a conserved structural similarity to pectate lyase e (pele). although similar in structure and sequence, the enzymatic characteristics of pela differ from those for pele. a structural alignment of pela and pele reveals differences in the t1.5 loop. the sequence of the t1.5 loop in pela was mutated to the homologous sequence in pele. the crystal structur ... | 2003 | 12832805 |
| first crystallographic structure of a xylanase from glycoside hydrolase family 5: implications for catalysis. | the room-temperature structure of xylanase (ec 3.2.1.8) from the bacterial plant pathogen erwinia chrysanthemi expressed in escherichia coli, a 45 kda, 413-amino acid protein belonging to glycoside hydrolase family 5, has been determined by multiple isomorphous replacement and refined to a resolution of 1.42 a. this represents the first structure of a xylanase not belonging to either glycoside hydrolase family 10 or family 11. the enzyme is composed of two domains similar to most family 10 xylan ... | 2003 | 12859186 |
| biogenesis of fe-s cluster by the bacterial suf system: sufs and sufe form a new type of cysteine desulfurase. | biosynthesis of iron-sulfur clusters (fe-s) depends on multiprotein systems. recently, we described the suf system of escherichia coli and erwinia chrysanthemi as being important for fe-s biogenesis under stressful conditions. the suf system is made of six proteins: sufc is an atypical cytoplasmic abc-atpase, which forms a complex with sufb and sufd; sufa plays the role of a scaffold protein for assembly of iron-sulfur clusters and delivery to target proteins; sufs is a cysteine desulfurase whic ... | 2003 | 12876288 |
| [the bactericidal activity of lectins from nitrogen-fixing bacilli]. | lectins i and ii isolated from the nitrogen-fixing soil bacterium paenibacillus polymyxa 1460 were found to be able to suppress the growth of rhizobium leguminosarum 252 and bacillus subtilis 36 at nearly all the concentrations tested (from 1 to 10 micrograms/ml). lectin i was also inhibitory to azospirillum brasilense 245 and erwinia carotovora subsp. citrulis 603, while lectin ii exerted bactericidal activity against xanthomonas campestris b-610 and b-611 and a. brasilense 245. the bacillar le ... | 2003 | 12901008 |
| novel bacteria degrading n-acylhomoserine lactones and their use as quenchers of quorum-sensing-regulated functions of plant-pathogenic bacteria. | bacteria degrading the quorum-sensing (qs) signal molecule n-hexanoylhomoserine lactone were isolated from a tobacco rhizosphere. twenty-five isolates degrading this homoserine lactone fell into six groups according to their genomic rep-pcr and rrs pcr-rflp profiles. representative strains from each group were identified as members of the genera pseudomonas, comamonas, variovorax and rhodococcus: all these isolates degraded n-acylhomoserine lactones other than the hexanoic acid derivative, albei ... | 2003 | 12904538 |
| erwinia chrysanthemi tolc is involved in resistance to antimicrobial plant chemicals and is essential for phytopathogenesis. | tolc is the outer-membrane component of several multidrug resistance (mdr) efflux pumps and plays an important role in the survival and virulence of many gram-negative bacterial animal pathogens. we have identified and characterized the outer-membrane protein-encoding gene tolc in the bacterial plant pathogen erwinia chrysanthemi ec16. the gene was found to encode a 51-kda protein with 70% identity to its escherichia coli homologue. the e. chrysanthemi gene was able to functionally complement th ... | 2003 | 13129948 |
| structure of the o-polysaccharide of erwinia carotovora ssp. carotovora gspb 436. | the o-polysaccharide of a phytopathogenic bacterium, erwinia carotovora ssp. carotovora gspb 436, was studied by sugar and methylation analysis, along with 1h and 13c nmr spectroscopy. the following structure of the branched tetrasaccharide repeating unit of the o-polysaccharide was established: [carbohydrate structure in text] the o-polysaccharide contains a minor proportion of 4-o-methylrhamnose, which is suggested to terminate the polymer main chain. | 2003 | 14499581 |
| characterization of the hrp pathogenicity cluster of erwinia carotovora subsp. carotovora: high basal level expression in a mutant is associated with reduced virulence. | extracellularly targeted proteins are crucial for virulence of gram-negative phytopathogenic bacteria. erwinia carotovora subsp. carotovora employs the so-called type ii (gsp) pathway to secrete a number of pectinases and cellulases, which cause the typical tissue maceration symptoms of soft-rot disease. the type iii (hrp) pathway is the major virulence determinant in the genera pseudomonas, ralstonia and xanthomonas, and in non-macerating species of erwinia. the hrp cluster was recently partial ... | 2003 | 14576934 |
| the pmra-pmrb two-component system responding to acidic ph and iron controls virulence in the plant pathogen erwinia carotovora ssp. carotovora. | efficient response to environmental cues is crucial to successful infection by plant-pathogenic bacteria such as erwinia carotovora ssp. carotovora. the expression of the main virulence genes of this pathogen, encoding extracellular enzymes that degrade the plant-cell wall, is subject to complex regulatory machinery where two-component systems play an important role. in this paper, we describe for the first time the involvement of the pmra-pmrb two-component system in regulation of virulence in ... | 2003 | 14617142 |
| carboxymethylproline synthase (carb), an unusual carbon-carbon bond-forming enzyme of the crotonase superfamily involved in carbapenem biosynthesis. | carboxymethylproline synthase (carb) catalyzes the committed step in the biosynthesis of (r)-1-carbapen-2-em-3-carboxylate, the simplest member of the carbapenem family of beta-lactam antibiotics, some of which are used clinically. carb displays sequence homology with members of the crotonase family including enoyl-coa hydratase (crotonase) and methylmalonyl-coa decarboxylase. the carb reaction has been proposed to comprise condensation of acetyl coenzyme a (accoa) and glutamate semi-aldehyde to ... | 2004 | 14625287 |
| quantification of disease progression of several microbial pathogens on arabidopsis thaliana using real-time fluorescence pcr. | an accurate monitoring of disease progression is important to evaluate disease susceptibility phenotypes. over the years, arabidopsis thaliana has become the model species to serve as a host in plant-pathogen interactions. despite the efforts to study genetic mechanisms of host defense, little efforts are made for a thorough pathogen assessment, often still depending on symptomology. this manuscript describes the use of real-time polymerase chain reaction (pcr) to assess pathogen growth in the h ... | 2003 | 14638430 |
| oxidative burst elicited by bacillus mycoides isolate bac j, a biological control agent, occurs independently of hypersensitive cell death in sugar beet. | response of sugar beet cultivars c40 and ush11 to syringe infiltration of live and dead bacillus mycoides isolate bac j, a biological control agent, and virulent and avirulent isolates of erwinia carotovora pv. betavasculorum was measured by monitoring systemic acquired resistance control of cercospora beticola, specific activity of chitinase and beta-glucanase, the oxidative burst, and hypersensitive cell death at the infiltration site. priming sugar beet with b. mycoides bac j (1 x 10(8) cells ... | 2003 | 14651348 |
| hydrodynamic properties of oxidized extracellular polysaccharides from erwinia chrysanthemi spp. | the molecular weights of the native polysaccharides of erwinia chrysanthemi strains range from 1.8 to 7.1 x 10(6) and their hydrodynamic properties are those of polydisperse, polyanionic biopolymers with pseudoplastic, non-thixotropic flow characteristics in aqueous solutions. the effect on the hydrodynamic properties of the polysaccharides by adding carboxyl groups to increase the charge density is studied, with particular reference to their molecular weight (mw), viscosity and conformation. in ... | 2003 | 14670735 |
| the crystal structure of pectate lyase pel9a from erwinia chrysanthemi. | the "family 9 polysaccharide lyase" pectate lyase l (pel9a) from erwinia chrysanthemi comprises a 10-coil parallel beta-helix domain with distinct structural features including an asparagine ladder and aromatic stack at novel positions within the superhelical structure. pel9a has a single high affinity calcium-binding site strikingly similar to the "primary" calcium-binding site described previously for the family pel1a pectate lyases, and there is strong evidence for a common second calcium ion ... | 2004 | 14670977 |
| cloning of the pela gene from bacillus licheniformis 14a and biochemical characterization of recombinant, thermostable, high-alkaline pectate lyase. | the pectate lyase gene pela from alkaliphilic bacillus licheniformis strain 14a was cloned and sequenced. the nucleotide sequence corresponded to an open reading frame of 1,026 bp that codes for a 39 amino acid signal peptide and a mature protein with a molecular mass of 33,451 da. the mature pela showed significant homology to other pectate lyases belonging to polysaccharide lyase family 1, such as enzymes from different bacillus spp. and erwinia chrysanthemi. the pela gene was expressed in esc ... | 2004 | 14673544 |
| synthesis of (3s,5r)-carbapenam-3-carboxylic acid and its role in carbapenem biosynthesis and the stereoinversion problem. | (5r)-carbapenem-3-carboxylic acid is the simplest structurally among the naturally occurring carbapenem beta-lactam antibiotics. it is the produced from (3s,5s)-carbapenam-3-carboxylic acid utilizing a remarkable stereoinversion/desaturation process by carc (carbapenem synthase), an alpha-ketoglutarate dependent non-heme iron oxygenase. in this communication, we demonstrate for the first time that the epimeric (3s,5r)-carbapenam-3-carboxylic acid is an intermediate in the overall catalytic cycle ... | 2003 | 14677956 |
| crystallization of the pectate lyase peli from erwinia chrysanthemi and sad phasing of a gold derivative. | the pectate lyase peli is involved in the degradation of plant tissues by the phytopathogenic bacterium erwinia chrysanthemi. it has been crystallized from a solution containing peg 550 in the space group p2(1), with unit-cell parameters a = 61.6, b = 70.7, c = 73.4 a, beta = 112.8 degrees. crystals diffract to 1.45 a using synchrotron radiation. sad phases have been computed from a gold-derivative crystal at the wavelength of maximum absorption (l(iii) edge). | 2004 | 14684926 |
| an evolutionary hot spot: the pngr234b replicon of rhizobium sp. strain ngr234. | rhizobium sp. strain ngr234 has an exceptionally broad host range and is able to nodulate more than 112 genera of legumes. since the overall organization of the ngr234 genome is strikingly similar to that of the narrow-host-range symbiont rhizobium meliloti strain 1021 (also known as sinorhizobium meliloti), the obvious question is why are the spectra of hosts so different? study of the early symbiotic genes of both bacteria (carried by the syma plasmids) did not provide obvious answers. yet, bo ... | 2004 | 14702322 |
| insecticidal bacillus thuringiensis silences erwinia carotovora virulence by a new form of microbial antagonism, signal interference. | it is commonly known that bacteria may produce antibiotics to interfere with the normal biological functions of their competitors in order to gain competitive advantages. here we report that bacillus thuringiensis suppressed the quorum-sensing-dependent virulence of plant pathogen erwinia carotovora through a new form of microbial antagonism, signal interference. e. carotovora produces and responds to acyl-homoserine lactone (ahl) quorum-sensing signals to regulate antibiotic production and expr ... | 2004 | 14766576 |
| characterization of atypical erwinia carotovora strains causing blackleg of potato in brazil. | to determine the characteristics of bacteria associated with the blackleg disease of potato in brazil and compare them with species and subspecies of pectolytic erwinia. | 2004 | 14962133 |
| analysis of erwinia chrysanthemi ec16 pele::uida, pell::uida, and hrpn::uida mutants reveals strain-specific atypical regulation of the hrp type iii secretion system. | the plant pathogen erwinia chrysanthemi produces a variety of factors that have been implicated in its ability to cause soft-rot diseases in various hosts. these include hrpn, a harpin secreted by the hrp type iii secretion system; pele, one of several major pectate lyase isozymes secreted by the type ii system; and pell, one of several secondary pels secreted by the type ii system. we investigated these factors in e. chrysanthemi ec16 with respect to the effects of medium composition and growth ... | 2004 | 14964532 |
| the rhas activator controls the erwinia chrysanthemi 3937 genes rhin, rhit and rhie involved in rhamnogalacturonan catabolism. | erwinia chrysanthemi causes soft-rot diseases of various plants by enzymatic degradation of the pectin in plant cell walls. the linear regions of pectin are composed of an acidic sugar, d-galacturonic acid. the ramified regions of pectin also include neutral sugars, and are rich in l-rhamnose residues. e. chrysanthemi is able to degrade these polysaccharides, polygalacturonate and rhamnogalacturonate. in e. chrysanthemi, the production of pectinases acting on linear regions is induced in the pre ... | 2004 | 14982630 |
| molecular cloning of a cytosolic ascorbate peroxidase cdna from cell cultures of sweet potato and its expression in response to stress. | a cdna encoding a cytosolic ascorbate peroxidase (apx), swapx1, was isolated from cell cultures of sweet potato ( ipomoea batatas) by cdna library screening, and its expression in the context of various environmental stresses was investigated. swapx1 contains an orf of 250 amino acids (27.5 kda) encoding a protein with a pi value of 5.32. the swapx1 orf does not code for a transit peptide, suggesting that the product is a cytosolic isoform. rna blot analysis showed that swapx1 gene is expressed ... | 2004 | 14986108 |
| systematic analysis, by the yeast two-hybrid, of protein interaction between components of the type ii secretory machinery of erwinia chrysanthemi. | type ii systems allow for the secretion of numerous enzymes and toxins in several gram-negative pathogens. in erwinia chrysanthemi, 14 out proteins are necessary for building the type ii apparatus. we performed a systematic two-hybrid analysis to test interactions between the periplasmic regions of the out proteins. results obtained using this approach suggested that outj (a pseudopilin) was able to interact with (i) outd, the outer membrane secretin, (ii) outi, mainly located in the periplasm, ... | 2004 | 14990257 |
| one-step purification and kinetic properties of the recombinant l-asparaginase from erwinia carotovora. | ecar-lans, the recombinant l-asparaginase from erwinia carotovora, is a prospective therapeutic enzyme for leukaemia treatment. an efficient and economical scheme was developed for the purification, cloning and expression in eschericha coli of ecar-lans. more than 90% purity, complemented with 72% active enzyme recovery, was achieved with a single chromatographic purification step. the activity of purified l-asparaginase was 630 i.u./mg. the ecar-lans k (m) value was 98x10(-6) m for the main phy ... | 2004 | 15032742 |
| thermodependence of growth and enzymatic activities implicated in pathogenicity of two erwinia carotovora subspecies (pectobacterium spp.). | erwinia carotovora subsp. atroseptica and erwinia carotovora subsp. carotovora can cause substantial damage to economically important plant crops and stored products. the occurrence of the disease and the scale of the damage are temperature dependent. disease development consists first of active multiplication of the bacteria in the infection area and then production of numerous extracellular enzymes. we investigated the effects of various temperatures on these two steps. we assayed the specific ... | 2004 | 15052318 |
| transfer of tuber soft rot and early blight resistances from solanum brevidens into cultivated potato. | tuber soft rot and early blight are serious potato diseases. development of potato varieties resistant to these diseases has been hindered by the scarcity of resistant germplasm. a diploid wild species, solanum brevidens, shows significant resistance to both diseases. numerous potato breeding lines have been developed from a potato- s. brevidens somatic hybrid, a206. a bc(3) clone, c75-5+297, derived from this somatic hybrid as well as its bc(1) and bc(2) parental lines showed resistance to both ... | 2004 | 15052402 |
| genomic diversity of erwinia carotovora subsp. carotovora and its correlation with virulence. | we used genetic and biochemical methods to examine the genomic diversity of the enterobacterial plant pathogen erwinia carotovora subsp. carotovora. the results obtained with each method showed that e. carotovora subsp. carotovora strains isolated from one ecological niche, potato plants, are surprisingly diverse compared to related pathogens. a comparison of 23 partial mdh sequences revealed a maximum pairwise difference of 10.49% and an average pairwise difference of 2.13%, values which are mu ... | 2004 | 15128563 |
| fast screening method for detection of acyl-hsl-degrading soil isolates. | a reliable method was developed for screening of bacteria isolates capable of degrading acyl-hsls, the signal molecules in quorum-sensing-mediated processes of many proteobacteria. the microtiter assay was based on the use of a gfp-marked escherichia coli strain, which fluoresces upon the presence of acyl-hsls. measurement of gfp fluorescence with a molecular imager fx scanner (fluorometer) detected isolates capable of degrading acyl-hsls. the potential of this method was demonstrated by isolati ... | 2004 | 15134889 |
| partitioning of the variance in the growth parameters of erwinia carotovora on vegetable products. | the objective of this paper was to estimate and partition the variability in the microbial growth model parameters describing the growth of erwinia carotovora on pasteurised and non-pasteurised vegetable juice from laboratory experiments performed under different temperature-varying conditions. we partitioned the model parameter variance and covariance components into effects due to temperature profile and replicate using a maximum likelihood technique. temperature profile and replicate were tre ... | 2004 | 15135958 |
| definition of a consensus dna-binding site for pecs, a global regulator of virulence gene expression in erwinia chrysanthemi and identification of new members of the pecs regulon. | in erwinia chrysanthemi, production of pectic enzymes is modulated by a complex network involving several regulators. one of them, pecs, which belongs to the marr family, also controls the synthesis of various other virulence factors, such as cellulases and indigoidine. here, the pecs consensus-binding site is defined by combining a systematic evolution of ligands by an exponential enrichment approach and mutational analyses. the consensus consists of a 23-base pair palindromic-like sequence (c( ... | 2004 | 15140891 |
| differential expression of 10 sweetpotato peroxidase genes in response to bacterial pathogen, pectobacterium chrysanthemi. | to understand the function of each peroxidase (pod, ec 1.11.1.7) in terms of biotic stress, changes in pod specific activity and expression of 10 pod genes were investigated in four cultivars of sweetpotato (ipomoea batatas) after infection with pectobacterium chrysanthemi. pod specific activity (units mg(-1) protein) increased from 16 h after inoculation (hai) in three varieties. pod activities of two cultivars, shinwhangmi and white star, reached a maximum level at 24 hai by about three times ... | 2004 | 15191750 |
| the erwinia chrysanthemi ec16 hrp/hrc gene cluster encodes an active hrp type iii secretion system that is flanked by virulence genes functionally unrelated to the hrp system. | erwinia chrysanthemi is a host-promiscuous plant pathogen that possesses a type iii secretion system (ttss) similar to that of the host-specific pathogens e. amylovora and pseudomonas syringae. the regions flanking the ttss-encoding hrp/hrc gene clusters in the latter pathogens encode various ttss-secreted proteins. dna sequencing of the complete e. chrysanthemi hrp/hrc gene cluster and approximately 12 kb of the flanking regions (beyond the previously characterized heca adhesin gene in the left ... | 2004 | 15195947 |
| transgenic potatoes expressing a novel cationic peptide are resistant to late blight and pink rot. | potato is the world's largest non-cereal crop. potato late blight is a pandemic, foliar wasting potato disease caused by phytophthora infestans, which has become highly virulent, fungicide resistant, and widely disseminated. similarly, fungicide resistant isolates of phytophthora erythroseptica, which causes pink rot, have also become an economic scourge of potato tubers. thus, an alternate, cost effective strategy for disease control has become an international imperative. here we describe a st ... | 2004 | 15198205 |
| isolation and characterisation of a class of carbohydrate oxidases from higher plants, with a role in active defence. | in a search for novel plant-derived antimicrobial proteins, we screened extracts from salicylic acid (sa)-treated lettuce and sunflower leaves. these extracts displayed very potent antimicrobial activity against a set of phytopathogens. characterisation of these extracts revealed that in both extracts, proteins of approximately 60 kda were responsible for the antimicrobial activity. further characterisation of these proteins and cloning of the respective cdnas revealed close homology to a range ... | 2004 | 15225281 |
| structure and hydrodynamic properties of the extracellular polysaccharide from a mutant strain (ra3w) of erwinia chrysanthemi ra3. | the structure of the extracellular polysaccharide (eps) produced by erwinia chrysanthemi strain ra3w, a mutant strain of e. chrysanthemi ra3, has been determined using low pressure size-exclusion and anion-exchange chromatographies, high ph anion-exchange chromatography, glycosyl linkage analysis, and 1d 1h nmr spectroscopy. the polysaccharide is structurally similar, if not identical, to the family of eps produced by such as e. chrysanthemi strains ech9, ech9sm6, and sr260. the molecular weight ... | 2004 | 15261600 |
| the global regulator genes from biocontrol strain serratia plymuthica ic1270: cloning, sequencing, and functional studies. | the biocontrol activity of various fluorescent pseudomonads towards plant-pathogenic fungi is dependent upon the gaca/gacs-type two-component system of global regulators and the rpos transcription sigma factor. in particular, these components are required for the production of antifungal antibiotics and exoenzymes. to investigate the effects of these global regulators on the expression of biocontrol factors by plant-associated bacteria other than pseudomonas spp., gaca/gacs and rpos homologues w ... | 2004 | 15262936 |
| genome sequence of the enterobacterial phytopathogen erwinia carotovora subsp. atroseptica and characterization of virulence factors. | the bacterial family enterobacteriaceae is notable for its well studied human pathogens, including salmonella, yersinia, shigella, and escherichia spp. however, it also contains several plant pathogens. we report the genome sequence of a plant pathogenic enterobacterium, erwinia carotovora subsp. atroseptica (eca) strain scri1043, the causative agent of soft rot and blackleg potato diseases. approximately 33% of eca genes are not shared with sequenced enterobacterial human pathogens, including s ... | 2004 | 15263089 |
| assessment of genetic variability of haploids extracted from tetraploid (2n = 4x = 48) solanum tuberosum. | the objectives of this study were to assess the genetic variability of haploids (2n = 2x = 24) extracted from tetraploid solanum tuberosum through 4x x 2x crosses with solanum phureja. molecular and phenotypic analyses were performed to fingerprint the genotypes used and to evaluate their potential use in breeding programs. aflp analysis revealed the presence of specific bands derived from the tetraploid seed parent s. phureja, as well as ex novo originated bands. on average, 210 bands were visu ... | 2004 | 15284867 |
| erwinia chrysanthemi o antigen is required for betaine osmoprotection in high-salt media. | cellular components necessary for osmoprotection are poorly known. in this study we show that o antigen is specifically required for the effectiveness of betaines as osmoprotectants for erwinia chrysanthemi in saline media. the phenotype is correlated with the inability of rfb mutant strains to maintain a high accumulation level of betaines in hypersaline media. | 2004 | 15292161 |
| characterization of metabolic pathway of linoleic acid 9-hydroperoxide in cytosolic fraction of potato tubers and identification of reaction products. | potato tubers are shown to contain a unique lipoxygenase pathway to form 9-hydroperoxy-10,12-octadecadienoic acid (9-hpode) from linoleic acid. here, we report the metabolic pathway of 9-hpode in the cytosolic fraction and the characterization of enzymes involved in the conversion of metabolites. the analysis of enzymatic reaction products at ph 5.5 revealed the formation of 9-keto-10,12-octadecadienoic acid, 9-hydroxy-10,12-octadecadienoic acid, 9,10-epoxy-11-hydroxy-12-octadecenoic acid, 9,10, ... | 2004 | 15304744 |
| potato plants genetically modified to produce n-acylhomoserine lactones increase susceptibility to soft rot erwiniae. | many gram-negative bacteria employ n-acylhomoserine lactones (ahl) to regulate diverse physiological processes in concert with cell population density (quorum sensing [qs]). in the plant pathogen erwinia carotovora, the ahl synthesized via the cari/expi genes are responsible for regulating the production of secreted plant cell wall-degrading exoenzymes and the antibiotic carbapen-3-em carboxylic acid. we have previously shown that targeting the product of an ahl synthase gene (yeni) from yersini ... | 2004 | 15305609 |
| genome update: promoter profiles. | | 2004 | 15347738 |
| genetic elucidation of nitric oxide signaling in incompatible plant-pathogen interactions. | recent experiments indicate that nitric oxide (no) plays a pivotal role in disease resistance and several other physiological processes in plants. however, most of the current information about the function of no in plants is based on pharmacological studies, and additional approaches are therefore required to ascertain the role of no as an important signaling molecule in plants. we have expressed a bacterial nitric oxide dioxygenase (nod) in arabidopsis plants and/or avirulent pseudomonas syrin ... | 2004 | 15347797 |
| bacterial ghost technology for pesticide delivery. | bacterial ghosts are nondenaturated empty cell envelopes of gram-negative bacteria produced by e-mediated lysis. such envelopes from the plant-adhering bacterium pectobacterium cypripedii were tested for their ability to adhere to plant material and to be used as carriers for pesticide delivery. we show, using fluorescence-labeled p. cypripedii ghosts, that depending on the target plants 55 or 10% (rice or soya, respectively) of the applied bacterial ghosts was retained on the leaves after heavy ... | 2004 | 15373403 |
| the secretome of the plant pathogenic bacterium erwinia chrysanthemi. | erwinia chrysanthemi causes soft-rot diseases of many plants by secreting a battery of enzymes which degrade the plant cell walls. we initiated a proteomic analysis to create a reference map of the e. chrysanthemi secretome. extracellular proteins were isolated from e. chrysanthemi culture supernatants and resolved by two-dimensional electrophoresis. by analysis of mutants, western blotting, and matrix-assisted laser desorption/ionization-time of flight (maldi-tof) 55 spots representing 25 uniqu ... | 2004 | 15378709 |
| some like it hot. | | 2004 | 15378808 |
| use of a pooled transposon mutation grid to demonstrate roles in disease development for erwinia carotovora subsp. atroseptica putative type iii secreted effector (dspe/a) and helper (hrpn) proteins. | soft rot erwinia spp., like other closely related plant pathogens, possess a type iii secretion system (ttss) (encoded by the hrp gene cluster) implicated in disease development. we report the sequence of the entire hrp gene cluster and adjacent dsp genes in erwinia carotovora subsp. atroseptica scri1039. the cluster is similar in content and structural organization to that in e. amylovora. however, eight putative genes of unknown function located within the e. carotovora subsp. atroseptica clus ... | 2004 | 15384484 |
| genome-wide identification of plant-upregulated genes of erwinia chrysanthemi 3937 using a gfp-based ivet leaf array. | a green fluorescent protein-based in vivo expression technology leaf array was used to identify genes in erwinia chrysanthemi 3937 that were specifically upregulated in plants compared with growth in a laboratory culture medium. of 10,000 e. chrysanthemi 3937 clones, 61 were confirmed as plant upregulated. on the basis of sequence similarity, these were recognized with probable functions in metabolism (20%), information transfer (15%), regulation (11%), transport (11%), cell processes (11%), and ... | 2004 | 15384490 |
| identification of an antibacterial compound, benzylideneacetone, from xenorhabdus nematophila against major plant-pathogenic bacteria. | an entomopathogenic bacterium, xenorhabdus nematophila, is known to have potent antibiotic activities to maintain monoxenic condition in its insect host for effective pathogenesis and ultimately for optimal development of its nematode symbiont, steinernema carpocapsae. in this study we assess its antibacterial activity against plant-pathogenic bacteria and identify its unknown antibiotics. the bacterial culture broth had significant antibacterial activity that increased with development of the b ... | 2004 | 15476972 |
| insights into the evolution of phytopathogens. | | 2004 | 15488387 |
| glutamine, glutamate, and alpha-glucosylglycerate are the major osmotic solutes accumulated by erwinia chrysanthemi strain 3937. | erwinia chrysanthemi is a phytopathogenic soil enterobacterium closely related to escherichia coli. both species respond to hyperosmotic pressure and to external added osmoprotectants in a similar way. unexpectedly, the pools of endogenous osmolytes show different compositions. instead of the commonly accumulated glutamate and trehalose, e. chrysanthemi strain 3937 promotes the accumulation of glutamine and alpha-glucosylglycerate, which is a new osmolyte for enterobacteria, together with glutam ... | 2004 | 15528516 |
| comparative genomics of the kdgr regulon in erwinia chrysanthemi 3937 and other gamma-proteobacteria. | in the plant-pathogenic enterobacterium erwinia chrysanthemi, almost all known genes involved in pectin catabolism are controlled by the transcriptional regulator kdgr. in this study, the comparative genomics approach was used to analyse the kdgr regulon in completely sequenced genomes of eight enterobacteria, including erw. chrysanthemi, and two vibrio species. application of a signal recognition procedure complemented by operon structure and protein sequence analysis allowed identification of ... | 2004 | 15528647 |
| involvement of n-acylhomoserine lactones throughout plant infection by erwinia carotovora subsp. atroseptica (pectobacterium atrosepticum). | erwinia carotovora subsp. atroseptica is responsible for potato blackleg disease in the field and tuber soft rot during crop storage. the process leading to the disease occurs in two phases: a primary invasion step followed by a maceration step. bacteria-to-bacteria communication is associated with a quorum-sensing (qs) process based on the production of n-acylhomoserine lactones (hsl). the role of hsl throughout plant infection was analyzed. to this purpose, hsl produced by a specific e. caroto ... | 2004 | 15553252 |
| [genetic regulation of pathogenicity and virulence factors in bacteria erwinia carotovora subsp. atroseptica: identification of kdud gene]. | a mutant that cannot utilize pectin substances of plant cell walls was obtained via insertion of mini-mini-tn5xyle transposon into the chromosome of phytopathogenic bacteria erwinia carotovora subsp. atroseptica. the inability of mutant cells to utilize these substrates was caused by a failure to accomplish the catabolism of unsaturated digalacturonic acid (uda). study of enzymatic activities has established that mutant bacteria lost the ability to produce 2,5-diketo-3-deoxygluconate dehydrogena ... | 2004 | 15559145 |
| [genetic regulation of pathogenicity and virulence factors in bacteria erwinia carotovora subsp. atroseptica: phenotypic characteristic of bacteria with the mutant kdud gene]. | in contrast to the closely related bacteria erwinia chrysanthemi, bacteria erwinia carotovora subsp. atroseptica produce lower levels of main pathogenicity and virulence factors (pectate lyases, cellulases, and proteases) in the presence of pectins. this effect was shown to be connected with the accumulation of the intermediate product of intracellular degradation of these substances, 2,5-diketo-3-deoxygluconate (dk2). the presence of dk2 in the culture broth of mutant bacteria, connected to its ... | 2004 | 15559146 |
| analysis of bgl operon structure and characterization of beta-glucosidase from pectobacterium carotovorum subsp. carotovorum ly34. | a putative bgl operon of pectobacterium carotovorum subsp. carotovorum ly34 (pcc ly34) was isolated. sequence analysis of the 5,557 bp cloned dna fragment (accession no. ay542524) showed three open reading frames (bglt, bglp, and bglb) predicted to encode 287, 633, and 468 amino acid proteins respectively. bglt and bglp orfs show high similarity to that of the pectobacterium chrysanthemi arbg antiterminator and arbf permease respectively. also, the latter contains most residues important for pho ... | 2004 | 15564664 |
| antibacterial activity of cichorium intybus. | antibacterial activity of the water, ethanol and ethyl acetate extracts of cichorium intybus was investigated. all the tested extracts showed antibacterial activity, the ethyl acetate extract being the most active. water extract inhibits agrobacterium radiobacter sp. tumefaciens, erwinia carotovora, pseudomonas fluorescens and p. aeruginosa. | 2004 | 15567253 |
| carboxymethylproline synthase from pectobacterium carotorova: a multifaceted member of the crotonase superfamily. | the simplest carbapenem antibiotic, (5r)-carbapen-2-em-3-carboxylic acid, is biosynthesized from primary metabolites in pectobacterium carotorova by the action of three enzymes, carboxymethylproline synthase (hereafter named carb), carbapenam synthetase, and carbapenem synthase. carb, a member of the crotonase superfamily, catalyzes the formation of (2s,5s)-5-carboxymethylproline from malonyl-coa and l-pyrroline-5-carboxylate. in this study we show that, in addition, carb catalyzes the independe ... | 2004 | 15595850 |
| identification and characterization of nip, necrosis-inducing virulence protein of erwinia carotovora subsp. carotovora. | erwinia carotovora subsp. carotovora is a gram-negative bacterium that causes soft rot disease of many cultivated crops. when a collection of e. carotovora subsp. carotovora isolates was analyzed on a southern blot using the harpin-encoding gene hrpn as probe, several harpinless isolates were found. regulation of virulence determinants in one of these, strain scc3193, has been characterized extensively. it is fully virulent on potato and in arabidopsis thaliana. an rpos (sigmas) mutant of scc319 ... | 2004 | 15597742 |
| chlorophyllase 1, a damage control enzyme, affects the balance between defense pathways in plants. | accumulation of reactive oxygen species (ros) is central to plant response to several pathogens. one of the sources of ros is the chloroplast because of the photoactive nature of the chlorophylls. chlorophyllase 1 (encoded by atclh1) of arabidopsis thaliana is quickly induced after tissue damage (e.g., caused by the bacterial necrotroph erwinia carotovora or the necrotrophic fungus alternaria brassicicola). rna interference silencing of atclh1 resulted in failure to degrade free chlorophyll afte ... | 2004 | 15598807 |
| erwinia chrysanthemi requires a second iron transport route dependent of the siderophore achromobactin for extracellular growth and plant infection. | full virulence of the pectinolytic enterobacterium erwinia chrysanthemi strain 3937 depends on the production in planta of the catechol-type siderophore chrysobactin. under iron-limited conditions, e. chrysanthemi synthesizes a second siderophore called achromobactin belonging to the hydroxy/carboxylate class of siderophore. in this study, we cloned and functionally characterized a 13 kb long operon comprising seven genes required for the biosynthesis (acs) and extracellular release (yhca) of ac ... | 2005 | 15612933 |
| the erwinia chrysanthemi type iii secretion system is required for multicellular behavior. | enterobacterial animal pathogens exhibit aggregative multicellular behavior, which is manifested as pellicles on the culture surface and biofilms at the surface-liquid-air interface. pellicle formation behavior requires production of extracellular polysaccharide, cellulose, and protein filaments, known as curli. protein filaments analogous to curli are formed by many protein secretion systems, including the type iii secretion system (ttss). here, we demonstrate that erwinia chrysanthemi, which d ... | 2005 | 15629935 |
| altering substrate chain length specificity of an acylhomoserine lactone synthase in bacterial communication. | quorum sensing mediated by specific signal compounds (autoinducers) allows bacteria to monitor their cell density and enables a synchronized regulation of target gene sets. the best studied group of autoinducers are the acylhomoserine lactones (ahsls), which are central to the regulation of virulence in many plant and animal pathogens. variation of the acyl side chain of the ahsls underlies the observed species specificity of this communication system. here we show that even different strains of ... | 2005 | 15634689 |
| degradation of acyl-homoserine lactone molecules by acinetobacter sp. strain c1010. | a bacterium c1010, isolated from the rhizospheres of cucumbers in fields in korea, degraded the microbial quorum-sensing molecules, hexanoyl homoserine lactone (hhsl), and octadecanoyl homoserine lactone (ohsl). morphological characteristics and 16s rrna sequence analysis identified c1010 as acinetobacter sp. strain c1010. this strain was able to degrade the acyl-homoserine lactones (ahls) produced by the biocontrol bacterium, pseudomonas chlororaphis o6, and a phytopathogenic bacterium, burkhol ... | 2004 | 15644910 |
| use of 1,4-naphthoquinones for control of erwinia carotovora. | the antimicrobial effect of 5 naphthoquinones was tested against the phytopathogenic bacteria erwinia carotovora. disk diffusion tests and determination of minimal inhibitory concentrations (mic) indicate that the compound naphthazarin (ntz) has the best antibacterial activity among the naphthoquinones tested. studies on the mode of action indicate the effect of ntz was bactericidal at 10 microg/ml. when cultivation was done in the presence of sodium ascorbate, the restoration of e. carotovora g ... | 2004 | 15644912 |
| sensitive and specific detection of xanthomonas campestris pv campestris by pcr using species-specific primers based on hrpf gene sequences. | a sensitive and specific assay was developed to detect bacterial black rot of crucifers caused by xanthomonas campestris pv. campestris (x. c. pv. campestris), in cabbage seed and plant. primers xcf and xcr from hrpf homologous to nolx, host recognition protein, were used to amplify a 525 bp dna fragment. pcr technique was applied to detect the pathogen in naturally infected seed and plant of cabbage. the pcr product was only produced from x. c. pv. campestris among 40 isolates of xanthomonas st ... | 2004 | 15646387 |
| escherichia coli-asparaginase (elspar) is superior to erwinia-asparaginase (erwinase) in childhood acute lymphoblastic leukaemia (all) induction--an early response study using minimal residual disease (mrd) markers. | | 2004 | 15651203 |
| ectopic expression of anthocyanin 5-o-glucosyltransferase in potato tuber causes increased resistance to bacteria. | the principal goal of this paper was to investigate the significance of anthocyanin 5-o-glucosyltransferase (5-ugt) for potato tuber metabolism. the ectopic expression of a 5-ugt cdna in the tuber improved the plant's defense against pathogen infection. the resistance of transgenic lines against erwinia carotovora subsp. carotovora was about 2-fold higher than for nontransformed plants. in most cases the pathogen resistance was accompanied by a significant increase in tuber yield. to investigate ... | 2005 | 15656661 |
| carbapenem antibiotic biosynthesis in erwinia carotovora is regulated by physiological and genetic factors modulating the quorum sensing-dependent control pathway. | erwinia carotovora produces the beta-lactam antibiotic, carbapenem, in response to a quorum sensing signalling molecule, n-(3-oxohexanoyl)-l-homoserine lactone (ohhl). we have mapped the ohhl-dependent promoter upstream of the first of the biosynthetic genes, cara. we have also analysed the effect on this promoter of the known genetic regulators of carbapenem expression, carr, cari (encoding homologues of luxr and luxi respectively) and hor (encoding a slya/marr-like transcriptional regulator). ... | 2005 | 15659168 |
| construction of minimum size cellulase (cel5z) from pectobacterium chrysanthemi py35 by removal of the c-terminal region. | pectobacterium chrysanthemi py35 secretes the endoglucanase cel5z, an enzyme of the glycoside hydrolase family 5. cel5z is a 426 amino acid, signal peptide (sp)-containing protein composed of two domains: a large n-terminal catalytic domain (cd; 291 amino acids) and a small c-terminal cellulose binding domain (cbd; 62 amino acids). these two domains are separated by a 30 amino acid linker region (lr). a truncated cel5z gene was constructed with the addition of a nonsense mutation that removes th ... | 2005 | 15666145 |