| function and expression of an n-acetylneuraminic acid-inducible outer membrane channel in escherichia coli. | the escherichia coli yjha (renamed nanc) gene encodes a protein of the kdgm family of outer membrane-specific channels. it is transcribed divergently from fimb, a gene involved in the site-specific inversion of the region controlling transcription of the fimbrial structural genes but is separated from it by one of the largest intergenic regions in e. coli. we show that nanc expression is induced by n-acetylneuraminic acid and modulated by n-acetylglucosamine. this regulation occurs via the nanr ... | 2005 | 15743943 |
| comparative genomic analysis of the ppt23a plasmid family of pseudomonas syringae. | members of the ppt23a plasmid family of pseudomonas syringae play an important role in the interaction of this bacterial pathogen with host plants. complete sequence analysis of several ppt23a family plasmids (pfps) has provided a glimpse of the gene content and virulence function of these plasmids. we constructed a macroarray containing 161 genes to estimate and compare the gene contents of 23 newly analyzed and eight known pfps from 12 pathovars of p. syringae, which belong to four genomospeci ... | 2005 | 15743960 |
| environmental ph sensing: resolving the vira/virg two-component system inputs for agrobacterium pathogenesis. | agrobacterium tumefaciens stands as one of biotechnology's greatest successes, with all plant genetic engineering building on the strategies of this pathogen. by integrating responses to external phs, phenols, and monosaccharides, this organism mobilizes oncogenic elements to efficiently transform most dicotyledonous plants. we now show that the complex signaling network used to regulate lateral gene transfer can be resolved as individual signaling modules. while ph and sugar perception are coup ... | 2005 | 15743967 |
| structural and biochemical analysis of the asc operon encoding 6-phospho-beta-glucosidase in pectobacterium carotovorum subsp. carotovorum ly34. | an asc operon of pectobacterium carotovorum subsp. carotovorum ly34 (pcc ly34) was isolated from a genomic library in a screen for beta-glucosidase activities. sequence analysis of the 5618-bp cloned dna fragment (accession number ay622309) showed three open reading frames (ascg, ascf, and ascb) that are predicted to encode 375, 486, and 476 amino acid proteins, respectively. the ascg orf shared a high similarity with the escherichia coli ascg repressor. the ascf orf shared 81% identity with the ... | 2004 | 15748978 |
| regulation and biosynthesis of carbapenem antibiotics in bacteria. | carbapenem antibiotics are members of the beta-lactam family of antibiotics, the most important class of antibiotics currently in clinical use. they are active against many important gram-positive and gram-negative pathogens. one important feature of carbapenem antibiotics is their resistance to several beta-lactamases. thienamycin, isolated from streptomyces cattleya, was the first carbapenem described. other well-studied carbapenems were isolated from the gram-negative bacteria erwinia carotov ... | 2005 | 15759042 |
| cloning and sequencing of a genomic island found in the brazilian purpuric fever clone of haemophilus influenzae biogroup aegyptius. | a genomic island was identified in the haemophilus influenzae biogroup aegyptius brazilian purpuric fever (bpf) strain f3031. this island, which was also found in other bpf isolates, could not be detected in non-bpf biogroup aegyptius strains or in nontypeable or typeable h. influenzae strains, with the exception of a region present in the type b eagan strain. this 34,378-bp island is inserted, in reference to h. influenzae rd kw20, within a choline transport gene and contains a mosaic structure ... | 2005 | 15784532 |
| flavobacterium johnsoniae gldj is a lipoprotein that is required for gliding motility. | cells of flavobacterium johnsoniae glide rapidly over surfaces by an unknown mechanism. eight genes required for gliding motility have been described. complementation of the nonmotile mutant uw102-48 identified another gene, gldj, that is required for gliding. gldj mutants formed nonspreading colonies, and individual cells were completely nonmotile. like previously described nonmotile mutants, gldj mutants were deficient in chitin utilization and were resistant to bacteriophages that infect wild ... | 2005 | 15805509 |
| azospirillum brasilense produces the auxin-like phenylacetic acid by using the key enzyme for indole-3-acetic acid biosynthesis. | an antimicrobial compound was isolated from azospirillum brasilense culture extracts by high-performance liquid chromatography and further identified by gas chromatography-mass spectrometry as the auxin-like molecule, phenylacetic acid (paa). paa synthesis was found to be mediated by the indole-3-pyruvate decarboxylase, previously identified as a key enzyme in indole-3-acetic acid (iaa) production in a. brasilense. in minimal growth medium, paa biosynthesis by a. brasilense was only observed in ... | 2005 | 15812004 |
| the 120 592 bp incf plasmid prsb107 isolated from a sewage-treatment plant encodes nine different antibiotic-resistance determinants, two iron-acquisition systems and other putative virulence-associated functions. | the antibiotic-multiresistance incf plasmid prsb107 was isolated by a transformation-based approach from activated-sludge bacteria of a wastewater-treatment plant. it confers resistance to ampicillin, penicillin g, chloramphenicol, erythromycin, kanamycin, neomycin, streptomycin, sulfonamides, tetracycline and trimethoprim and against mercuric ions. complete sequencing of this plasmid revealed that it is 120 592 bp in size and has a g+c content of 53.1 mol%. the plasmid backbone is composed of t ... | 2005 | 15817778 |
| identification of a new quorum-sensing-controlled virulence factor in erwinia carotovora subsp. atroseptica secreted via the type ii targeting pathway. | two-dimensional polyacrylamide gel electrophoresis of the secreted proteins of erwinia carotovora subsp. atroseptica revealed a low-abundance protein that was identified by mass spectrometry as a homologue of a xanthomonas campestris avirulence protein with unknown function. the predicted svx protein has an n-terminal signal sequence and zinc binding-region signature, and the mature protein is post-translationally modified. a 2d difference gel electrophoresis (dige) showed that the protein is se ... | 2005 | 15828685 |
| novel quorum-sensing-controlled genes in erwinia carotovora subsp. carotovora: identification of a fungal elicitor homologue in a soft-rotting bacterium. | seven new genes controlled by the quorum-sensing signal molecule n-(3-oxohexanoyl)-l-homoserine lactone (ohhl) have been identified in erwinia carotovora subsp. carotovora. using tnphoa as a mutagen, we enriched for mutants defective in proteins that could play a role in the interaction between e. carotovora subsp. carotovora and its plant hosts, and identified nipecc and its counterpart in e. carotovora subsp. atroseptica. these are members of a growing family of proteins related to nep1 from f ... | 2005 | 15828686 |
| lethal effect of the gliding arc discharges on erwinia spp. | to compare the decontamination performances of glidarc on strains of erwinia of industrial interest. | 2005 | 15836472 |
| autoinduction in erwinia amylovora: evidence of an acyl-homoserine lactone signal in the fire blight pathogen. | erwinia amylovora causes fire blight disease of apple, pear, and other members of the rosaceae. here we present the first evidence for autoinduction in e. amylovora and a role for an n-acyl-homoserine lactone (ahl)-type signal. two major plant virulence traits, production of extracellular polysaccharides (amylovoran and levan) and tolerance to free oxygen radicals, were controlled in a bacterial-cell-density-dependent manner. two standard autoinducer biosensors, agrobacterium tumefaciens ntl4 an ... | 2005 | 15838048 |
| spoilage of vegetable crops by bacteria and fungi and related health hazards. | after harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. the most common bacterial agents are erwinia carotovora, pseudomonas spp., corynebacterium, xanthomonas campestris, and lactic acid bacteria with e. carotovora being the most common, attacking virtually every vegetable type. fungi commonly causing spoilage of fresh vegetables are botrytis cinerea, various species of the genera alternaria, aspergillus, cladosporium, colleto ... | 2005 | 15839403 |
| polygalacturonase from sitophilus oryzae: possible horizontal transfer of a pectinase gene from fungi to weevils. | endo-polygalacturonase, one of the group of enzymes known collectively as pectinases, is widely distributed in bacteria, plants and fungi. the enzyme has also been found in several weevil species and a few other insects, such as aphids, but not in drosophila melanogaster, anopheles gambiae, or caenorhabditis elegans or, as far as is known, in any more primitive animal species. what, then, is the genetic origin of the polygalacturonases in weevils? since some weevil species harbor symbiotic micro ... | 2003 | 15841240 |
| the iron-siderophore transporter fhua is the receptor for the antimicrobial peptide microcin j25: role of the microcin val11-pro16 beta-hairpin region in the recognition mechanism. | the role of the outer-membrane iron transporter fhua as a potential receptor for the antimicrobial peptide mccj25 (microcin j25) was studied through a series of in vivo and in vitro experiments. the requirement for both fhua and the inner-membrane tonb-exbb-exbd complex was demonstrated by antibacterial assays using complementation of an fhua(-) strain and by using isogenic strains mutated in genes encoding the protein complex respectively. in addition, mccj25 was shown to block phage t5 infecti ... | 2005 | 15862112 |
| the rssab two-component signal transduction system in serratia marcescens regulates swarming motility and cell envelope architecture in response to exogenous saturated fatty acids. | serratia marcescens swarms at 30 degrees c but not at 37 degrees c on a nutrient-rich (lb) agar surface. mini-tn5 mutagenesis of s. marcescens ch-1 yielded a mutant (wc100) that swarms not only vigorously at 37 degrees c but also earlier and faster than the parent strain swarms at 30 degrees c. analysis of this mutant revealed that the transposon was inserted into a gene (rssa) predicted to encode a bacterial two-component signal transduction sensor kinase, upstream of which a potential response ... | 2005 | 15866926 |
| identification of extracellular n-acylhomoserine lactone acylase from a streptomyces sp. and its application to quorum quenching. | n-acylhomoserine lactones (ahls) play an important role in regulating virulence factors in pathogenic bacteria. recently, the enzymatic inactivation of ahls, which can be used as antibacterial targets, has been identified in several soil bacteria. in this study, strain m664, identified as a streptomyces sp., was found to secrete an ahl-degrading enzyme into a culture medium. the ahlm gene for ahl degradation from streptomyces sp. strain m664 was cloned, expressed heterologously in streptomyces l ... | 2005 | 15870355 |
| prevalence of pathogenicity island iicft073 genes among extraintestinal clinical isolates of escherichia coli. | uropathogenic escherichia coli is the most common cause of urinary tract infection (uti). cystitis in women is by far the most common uti; pyelonephritis in both sexes and prostatitis in men are more severe but are less frequent complaints. the ability of e. coli to cause uti is associated with specific virulence determinants, some of which are encoded on pathogenicity islands (pai). one such pai (pai iicft073), of the prototypical uropathogenic e. coli strain cft073, contains 116 open reading f ... | 2005 | 15872276 |
| the quorum-quenching lactonase from bacillus thuringiensis is a metalloprotein. | lactonases from bacillus species hydrolyze the n-acylhomoserine lactone (ahl) signaling molecules used in quorum-sensing pathways of many gram-negative bacteria, including pseudomonas aeruginosa and erwinia carotovora, both significant pathogens. because of sequence similarity, these ahl lactonases have been assigned to the metallo-beta-lactamase superfamily of proteins, which includes metalloenzymes of diverse activity, mechanism, and metal content. however, a recent study claims that ahl lacto ... | 2005 | 15895999 |
| purification and characterization of allophanate hydrolase (atzf) from pseudomonas sp. strain adp. | atzf, allophanate hydrolase, is a recently discovered member of the amidase signature family that catalyzes the terminal reaction during metabolism of s-triazine ring compounds by bacteria. in the present study, the atzf gene from pseudomonas sp. strain adp was cloned and expressed as a his-tagged protein, and the protein was purified and characterized. atzf had a deduced subunit molecular mass of 66,223, based on the gene sequence, and an estimated holoenzyme molecular mass of 260,000. the acti ... | 2005 | 15901697 |
| novel molecular features of the fibrolytic intestinal bacterium fibrobacter intestinalis not shared with fibrobacter succinogenes as determined by suppressive subtractive hybridization. | suppressive subtractive hybridization was conducted to identify unique genes coding for plant cell wall hydrolytic enzymes and other properties of the gastrointestinal bacterium fibrobacter intestinalis dr7 not shared by fibrobacter succinogenes s85. subtractive clones from f. intestinalis were sequenced and assembled to form 712 nonredundant contigs with an average length of 525 bp. of these, 55 sequences were unique to f. intestinalis. the remaining contigs contained 764 genes with blastx simi ... | 2005 | 15901698 |
| a gene encoding l-methionine gamma-lyase is present in enterobacteriaceae family genomes: identification and characterization of citrobacter freundii l-methionine gamma-lyase. | citrobacter freundii cells produce l-methionine gamma-lyase when grown on a medium containing l-methionine. the nucleotide sequence of the hybrid plasmid with a c. freundii ecori insert of about 3.0 kbp contained two open reading frames, consisting of 1,194 nucleotides and 1,296 nucleotides, respectively. the first one (denoted megl) encoded l-methionine gamma-lyase. the enzyme was overexpressed in escherichia coli and purified. the second frame encoded a protein belonging to the family of perme ... | 2005 | 15901718 |
| bacterial cell-to-cell signaling in the gastrointestinal tract. | | 2005 | 15908344 |
| evolutionary relationships of three new species of enterobacteriaceae living as symbionts of aphids and other insects. | ecological studies on three bacterial lineages symbiotic in aphids have shown that they impose a variety of effects on their hosts, including resistance to parasitoids and tolerance to heat stress. phylogenetic analyses of partial sequences of gyrb and reca are consistent with previous analyses limited to 16s rrna gene sequences and yield improved confidence of the evolutionary relationships of these symbionts. all three symbionts are in the enterobacteriaceae. one of the symbionts, here given t ... | 2005 | 15933033 |
| complete genome sequence of phihsic, a pseudotemperate marine phage of listonella pelagia. | the genome for the marine pseudotemperate member of the siphoviridae phihsic has been sequenced using a combination of linker amplification library construction, restriction digest library construction, and primer walking. phihsic enters into a pseudolysogenic relationship with its host, listonella pelagia, characterized by sigmoidal growth curves producing >10(9) cells/ml and >10(11) phage/ml. the genome (37,966 bp; g+c content, 44%) contained 47 putative open reading frames (orfs), 17 of which ... | 2005 | 15933034 |
| involvement of bacterial quorum-sensing signals in spoilage of bean sprouts. | bacterial communication signals, acylated homoserine lactones (ahls), were extracted from samples of commercial bean sprouts undergoing soft-rot spoilage. bean sprouts produced in the laboratory did not undergo soft-rot spoilage and did not contain ahls or ahl-producing bacteria, although the bacterial population reached levels similar to those in the commercial sprouts, 10(8) to 10(9) cfu/g. ahl-producing bacteria (enterobacteriaceae and pseudomonads) were isolated from commercial sprouts, and ... | 2005 | 15933035 |
| the tetr family of transcriptional repressors. | we have developed a general profile for the proteins of the tetr family of repressors. the stretch that best defines the profile of this family is made up of 47 amino acid residues that correspond to the helix-turn-helix dna binding motif and adjacent regions in the three-dimensional structures of tetr, qacr, cprb, and ethr, four family members for which the function and three-dimensional structure are known. we have detected a set of 2,353 nonredundant proteins belonging to this family by scree ... | 2005 | 15944459 |
| genetic modification of potato against microbial diseases: in vitro and in planta activity of a dermaseptin b1 derivative, msra2. | dermaseptin b1 is a potent cationic antimicrobial peptide found in skin secretions of the arboreal frog phyllomedusa bicolor. a synthetic derivative of dermaseptin b1, msra2 (n-met-dermaseptin b1), elicited strong antimicrobial activities against various phytopathogenic fungi and bacteria in vitro. to assess its potential for plant protection, msra2 was expressed at low levels (1-5 microg/g of fresh tissue) in the transgenic potato (solanum tuberosum l.) cv. desiree. stringent challenges of thes ... | 2005 | 15947906 |
| cloning, expression and characterisation of erwinia carotovora l-asparaginase. | bacterial l-asparaginases (e.c. 3.5.1.1) have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia. l-asparaginase from erwinia carotovora ncyc 1526 (era) was cloned and expressed in e. coli. the enzyme was purified to homogeneity by a two-step procedure comprising cation-exchange chromatography and affinity chromatography on immobilised l-asparagine. the enzymatic properties of the recombinant enzyme were investigated and the kinetic parameters (k(m), k(ca ... | 2005 | 15951039 |
| autofact: an automatic functional annotation and classification tool. | assignment of function to new molecular sequence data is an essential step in genomics projects. the usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets. | 2005 | 15960857 |
| [o2-* burst of tobacco leaves triggered by erwinia carotovora subsp. carotovora inoculation]. | o(-.)(2) production based on chemical method by ecc-treated intact tobacco leaves was observed. it showed a long-lasting one-phase course beginning 1 h and ending 14 h after erwinia carotovora subsp. carotovora (ecc) was inoculated. in ecc-treated leaves, o(-.)(2) production rate of 3 h is 2 times of 1 h, and of 10 h it remains 1.7 times. it decreases rapidly between 10 h and 14 h, at 14 h it falls to the level before inoculation. this is a completely different course from the widely accepted tw ... | 2005 | 15961909 |
| a generic approach for the design of whole-genome oligoarrays, validated for genomotyping, deletion mapping and gene expression analysis on staphylococcus aureus. | dna microarray technology is widely used to determine the expression levels of thousands of genes in a single experiment, for a broad range of organisms. optimal design of immobilized nucleic acids has a direct impact on the reliability of microarray results. however, despite small genome size and complexity, prokaryotic organisms are not frequently studied to validate selected bioinformatics approaches. relying on parameters shown to affect the hybridization of nucleic acids, we designed freely ... | 2005 | 15963225 |
| epimerase active domain of pseudomonas aeruginosa algg, a protein that contains a right-handed beta-helix. | the polysaccharide alginate forms a protective capsule for pseudomonas aeruginosa during chronic pulmonary infections. the structure of alginate, a linear polymer of beta1-4-linked o-acetylated d-mannuronate (m) and l-guluronate (g), is important for its activity as a virulence factor. alginate structure is mediated by algg, a periplasmic c-5 mannuronan epimerase. algg also plays a role in protecting alginate from degradation by the periplasmic alginate lyase algl. here, we show that the c-termi ... | 2005 | 15968068 |
| [expression of gene aiia carrying the promoter of gene cry3aa in bacillus thuringiensis]. | n-acyl-homoserine lactones (ahls), are widely conserved signal molecules present in quorum-sensing systems of many gram-negative bacteria. ahls molecules mediate the expression of virulence genes of a range of bacterial pathogens. recently, it has been reported that aiia protein, which widely exists in bacillus species, can inactivate the ahls by hydrolyzing the lactone bond of ahls, thus attenuate the diseases caused by the expression of virulence genes of bacterial pathogens. bacillus thuringi ... | 2003 | 15969053 |
| the map kinase substrate mks1 is a regulator of plant defense responses. | arabidopsis map kinase 4 (mpk4) functions as a regulator of pathogen defense responses, because it is required for both repression of salicylic acid (sa)-dependent resistance and for activation of jasmonate (ja)-dependent defense gene expression. to understand mpk4 signaling mechanisms, we used yeast two-hybrid screening to identify the mpk4 substrate mks1. analyses of transgenic plants and genome-wide transcript profiling indicated that mks1 is required for full sa-dependent resistance in mpk4 ... | 2005 | 15990873 |
| expr, a luxr homolog of erwinia carotovora subsp. carotovora, activates transcription of rsma, which specifies a global regulatory rna-binding protein. | n-acyl homoserine lactone (ahl) is required by erwinia carotovora subspecies for the expression of various traits, including extracellular enzyme and protein production and pathogenicity. previous studies with e. carotovora subsp. carotovora have shown that ahl deficiency causes the production of high levels of rsma, an rna binding protein that functions as a global negative regulator of extracellular enzymes and proteins and secondary metabolites (rsm, regulator of secondary metabolites). we do ... | 2005 | 15995194 |
| identification and characterization of a second lexa gene of xanthomonas axonopodis pathovar citri. | we previously identified and characterized a lexa gene from xanthomonas axonopodis pv. citri. for this study, we cloned and expressed a lexa homologue from x. axonopodis pv. citri. this gene was designated lexa2, and the previously identified lexa gene was renamed lexa1. the coding region of lexa2 is 606 bp long and shares 59% nucleotide sequence identity with lexa1. analyses of the deduced amino acid sequence revealed that lexa2 has structures that are characteristic of lexa proteins, including ... | 2005 | 16000766 |
| improvement of the fungal biocontrol agent trichoderma atroviride to enhance both antagonism and induction of plant systemic disease resistance. | biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. we determined whether transgenic strain sj3-4 of trichoderma atroviride, which expresses the aspergillus niger glucose oxidase-encoding gene, goxa, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. the transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxa expression occurred immediately ... | 2005 | 16000810 |
| [indicator system for studying the lysogenic development of temperate bacteriophage zf40 erwinia carotovora]. | the indicatory system for studying the lysogenic development of the moderate erwiniophage zf40 has been created on the basis of the data on the efficiency of inoculation, adsorption of phage particles on a cell, and cooperation between different clear-mutants. the use of the indicatory strains rc5297 and 62a-dl. derivatives of erwinia carotovora subsp. carotovora 62a, permitted dividing c-mutants of the phage zf40 into two types which, in their turn, include 4 groups of complementation (cooperat ... | 2005 | 16018206 |
| [the multiple character of mutation of resistance to mitomycin c in erwinia carotovora subsp. carotovora]. | it has been shown that mutants of erwinia carotovora subsp. carotovora (eca) resistant to mitomycin c could be characterized by the change of colonies morphology, sensitivity to bacteriocins, and by the change of pathogeneity. it is supposed that mutations responsible for the stability to mitomycin c touch the synthesis of cell membranes components. in some cases mcr-mutations caused cardinal changes--the loss of prototrophy and synthesis of carotinoid pigment. the mutants obtained in this work ... | 2005 | 16018213 |
| structure-activity relationships of erwinia carotovora quorum sensing signaling molecules. | production of virulence factors and secondary metabolites is regulated in the phytopathogen erwinia carotovora by quorum sensing involving n-acylated homoserine lactone (ahl) signaling molecules. non-hydrolyzable ahl analogues were synthesized and screened in vivo. the biological activity of each compound was correlated with its ability to bind erwinia ahl receptor proteins (luxr homologues) in vitro. there is an excellent correlation between carbapenem production in vivo and in vitro binding to ... | 2005 | 16051488 |
| drosophila host defense after oral infection by an entomopathogenic pseudomonas species. | drosophila has been shown to be a valuable model for the investigation of host-pathogen interactions. study of the drosophila immune response has been hampered, however, by the lack of true drosophila pathogens. in nearly all studies reported, the bacteria used were directly injected within the body cavity of the insect, bypassing the initial steps of a natural interaction. here, we report the identification of a previously uncharacterized bacterial species, pseudomonas entomophila (pe), which h ... | 2005 | 16061818 |
| crystal structure of the bacterial yhch protein indicates a role in sialic acid catabolism. | the yhch gene is part of the nan operon in bacteria that encodes proteins involved in sialic acid catabolism. determination of the crystal structure of yhch from haemophilus influenzae was undertaken as part of a structural genomics effort in order to assist with the functional assignment of the protein. the structure was determined at 2.2-a resolution by multiple-wavelength anomalous diffraction. the protein fold is a variation of the double-stranded beta-helix. two antiparallel beta-sheets for ... | 2005 | 16077096 |
| shigella dysenteriae shus promotes utilization of heme as an iron source and protects against heme toxicity. | shigella dysenteriae serotype 1, a major cause of bacillary dysentery in humans, can use heme as a source of iron. genes for the transport of heme into the bacterial cell have been identified, but little is known about proteins that control the fate of the heme molecule after it has entered the cell. the shus gene is located within the heme transport locus, downstream of the heme receptor gene shua. shus is a heme binding protein, but its role in heme utilization is poorly understood. in this wo ... | 2005 | 16077111 |
| allophanate hydrolase, not urease, functions in bacterial cyanuric acid metabolism. | growth substrates containing an s-triazine ring are typically metabolized by bacteria to liberate 3 mol of ammonia via the intermediate cyanuric acid. over a 25-year period, a number of original research papers and reviews have stated that cyanuric acid is metabolized in two steps to the 2-nitrogen intermediate urea. in the present study, allophanate, not urea, was shown to be the 2-nitrogen intermediate in cyanuric acid metabolism in all the bacteria examined. six different experimental results ... | 2005 | 16085834 |
| identification and characterization of putative virulence genes and gene clusters in aeromonas hydrophila ppd134/91. | aeromonas hydrophila is a gram-negative opportunistic pathogen of animals and humans. the pathogenesis of a. hydrophila is multifactorial. genomic subtraction and markers of genomic islands (gis) were used to identify putative virulence genes in a. hydrophila ppd134/91. two rounds of genomic subtraction led to the identification of 22 unique dna fragments encoding 19 putative virulence factors and seven new open reading frames, which are commonly present in the eight virulence strains examined. ... | 2005 | 16085838 |
| elevated temperature enhances virulence of erwinia carotovora subsp. carotovora strain ec153 to plants and stimulates production of the quorum sensing signal, n-acyl homoserine lactone, and extracellular proteins. | erwinia carotovora subsp. atroseptica, e. carotovora subsp. betavasculorum, and e. carotovora subsp. carotovora produce high levels of extracellular enzymes, such as pectate lyase (pel), polygalacturonase (peh), cellulase (cel), and protease (prt), and the quorum-sensing signal n-acyl-homoserine lactone (ahl) at 28 degrees c. however, the production of these enzymes and ahl by these bacteria is severely inhibited during growth at elevated temperatures (31.2 degrees c for e. carotovora subsp. atr ... | 2005 | 16085860 |
| e1 enzyme of the pyruvate dehydrogenase complex in corynebacterium glutamicum: molecular analysis of the gene and phylogenetic aspects. | the e1p enzyme is an essential part of the pyruvate dehydrogenase complex (pdhc) and catalyzes the oxidative decarboxylation of pyruvate with concomitant acetylation of the e2p enzyme within the complex. we analyzed the corynebacterium glutamicum acee gene, encoding the e1p enzyme, and constructed and characterized an e1p-deficient mutant. sequence analysis of the c. glutamicum acee gene and adjacent regions revealed that acee is not flanked by genes encoding other enzymes of the pdhc. transcrip ... | 2005 | 16109942 |
| [purification and properties of recombinant erwinia carotovora l-asparaginase expressed in e.coli cells]. | the method of purification erwinia carotovora recombinant l-asparaginase, expressed in e.coli, including ultrasonic disintegration of biomass, fractionation ammonium sulfate and column chromatography on cm- or sp-sepharose has been developed. according to sds-paage the enzyme preparation was homogeneous, its specific activity and yield consist respectively about 620 iu/mg of protein and 75%. physical-chemical and structural properties of recombinant erwinia carotovora l-asparaginase are similar ... | 2003 | 16119104 |
| gene stacking in phalaenopsis orchid enhances dual tolerance to pathogen attack. | cymbidium mosaic virus (cymmv) and erwinia carotovora have been reported to cause severe damage to orchid plants. to enhance the resistance of orchids to both viral and bacterial phytopathogens, gene stacking was applied on phalaenopsis orchid by double transformation. plbs originally transformed with cymmv coat protein cdna (cp) were then re-transformed with sweet pepper ferredoxin-like protein cdna (pflp) by agrobacterium tumefaciens, to enable expression of dual (viral and bacterial) disease ... | 2005 | 16145836 |
| novel lectin-like bacteriocins of biocontrol strain pseudomonas fluorescens pf-5. | bacteriocin llpa, produced by pseudomonas sp. strain bw11m1, is a peculiar antibacterial protein due to its homology to mannose-binding lectins mostly found in monocots (a. h. a. parret, g. schoofs, p. proost, and r. de mot, j. bacteriol. 185:897-908, 2003). biocontrol strain pseudomonas fluorescens pf-5 contains two llpa-like genes, named llpa1(pf-5) and llpa2(pf-5). recombinant escherichia coli cells expressing llpa1(pf-5) or llpa2(pf-5) acquired bacteriocin activity and secreted a 31-kda prot ... | 2005 | 16151105 |
| cog3926 and cog5526: a tale of two new lysozyme-like protein families. | we have identified two new lysozyme-like protein families by using a combination of sequence similarity searches, domain architecture analysis, and structural predictions. first, the p5 protein from bacteriophage phi8, which belongs to cog3926 and pfam family duf847, is predicted to have a new lysozyme-like domain. this assignment is consistent with the lytic function of p5 proteins observed in several related double-stranded rna bacteriophages. domain architecture analysis reveals two lysozyme- ... | 2005 | 16155206 |
| inhibitor of apoptosis 2 and tak1-binding protein are components of the drosophila imd pathway. | the imd signaling cascade, similar to the mammalian tnf-receptor pathway, controls antimicrobial peptide expression in drosophila. we performed a large-scale rnai screen to identify novel components of the imd pathway in drosophila s2 cells. in all, 6713 dsrnas from an s2 cell-derived cdna library were analyzed for their effect on attacin promoter activity in response to escherichia coli. we identified seven gene products required for the attacin response in vitro, including two novel imd pathwa ... | 2005 | 16163390 |
| cpx signal transduction is influenced by a conserved n-terminal domain in the novel inhibitor cpxp and the periplasmic protease degp. | in escherichia coli, envelope stress can be overcome by three different envelope stress responses: the sigma(e) stress response and the bae and cpx two-component systems. the cpx envelope stress response is controlled by the sensor kinase cpxa, the response regulator cpxr, and the novel periplasmic protein cpxp. cpxp mediates feedback inhibition of the cpx pathway through a hypothetical interaction with the sensing domain of cpxa. no informative homologues of cpxp are known, and thus it is uncle ... | 2005 | 16166523 |
| isolation and antifungal activity of 4-phenyl-3-butenoic acid from streptomyces koyangensis strain vk-a60. | an antifungal compound was isolated from the culture broth of streptomyces koyangensis strain vk-a60 using various chromatographic procedures. on the basis of the high-resolution ei-mass and 1h and 13c nmr data, the compound was identified as 4-phenyl-3-butenoic acid. colletotrichum orbiculare, magnaporthe grisea, and pythium ultimum were most sensitive to 4-phenyl-3-butenoic acid. strong inhibitory effects of 4-phenyl-3-butenoic acid also were found against pectobacterium carotovorum subsp. car ... | 2005 | 16190619 |
| flavobacterium johnsoniae gliding motility genes identified by mariner mutagenesis. | cells of flavobacterium johnsoniae glide rapidly over surfaces. the mechanism of f. johnsoniae gliding motility is not known. eight gld genes required for gliding motility have been described. disruption of any of these genes results in complete loss of gliding motility, deficiency in chitin utilization, and resistance to bacteriophages that infect wild-type cells. two modified mariner transposons, himarem1 and himarem2, were constructed to allow the identification of additional motility genes. ... | 2005 | 16199564 |
| towards the identification of type ii secretion signals in a nonacylated variant of pullulanase from klebsiella oxytoca. | pullulanase (pula) from the gram-negative bacterium klebsiella oxytoca is a 116-kda surface-anchored lipoprotein of the isoamylase family that allows growth on branched maltodextrin polymers. pula is specifically secreted via a type ii secretion system. pelbsp-pula, a nonacylated variant of pula made by replacing the lipoprotein signal peptide (sp) with the signal peptide of pectate lyase pelb from erwinia chrysanthemi, was efficiently secreted into the medium. two 80-amino-acid regions of pula, ... | 2005 | 16199575 |
| helicase89b is a mot1p/btaf1 homologue that mediates an antimicrobial response in drosophila. | we have identified a novel component, helicase89b, that is required for the inducible antimicrobial response in drosophila larvae by means of a p-element insertional genetic screen. helicase89b belongs to the mot1p/btaf1 subfamily of snf2-like atpases. this subfamily can interact with tata-binding proteins, but whether the interaction leads to gene activation or repression is being debated. we found that helicase89b is required for the inducible expression of antimicrobial peptide genes but not ... | 2005 | 16200050 |
| hfq-dependent regulation of ompa synthesis is mediated by an antisense rna. | this paper shows that the small rna mica (previously srad) is an antisense regulator of ompa in escherichia coli. mica accumulates upon entry into stationary phase and down-regulates the level of ompa mrna. regulation of ompa (outer membrane protein a), previously attributed to hfq/mrna binding, is lost upon deletion of the mica gene, whereas overexpression of mica inhibits the synthesis of ompa. in vitro, mica binds to the ompa mrna leader. enzymatic and chemical probing was used to map the str ... | 2005 | 16204185 |
| salmonella enterica virulence genes are required for bacterial attachment to plant tissue. | numerous salmonella enterica food-borne illness outbreaks have been associated with contaminated vegetables, in particular sprouted seeds, and the incidence of reported contamination has steadily risen. in order to understand the physiology of s. enterica serovar newport on plants, a screen was developed to identify transposon mutants that were defective in attachment to alfalfa sprouts. twenty independent mutants from a pool of 6,000 were selected for reduced adherence to alfalfa sprouts. sixty ... | 2005 | 16204476 |
| production of an engineered killer peptide in nicotiana benthamiana by using a potato virus x expression system. | the decapeptide killer peptide (kp) derived from the sequence of a single-chain, anti-idiotypic antibody acting as a functional internal image of a microbicidal, broad-spectrum yeast killer toxin (kt) was shown to exert a strong microbicidal activity against human pathogens. with the aim to exploit this peptide to confer resistance to plant pathogens, we assayed its antimicrobial activity against a broad spectrum of phytopathogenic bacteria and fungi. synthetic kp exhibited antimicrobial activit ... | 2005 | 16204558 |
| evolutionary, structural and functional relationships revealed by comparative analysis of syntenic genes in rhizobiales. | comparative genomics has provided valuable insights into the nature of gene sequence variation and chromosomal organization of closely related bacterial species. however, questions about the biological significance of gene order conservation, or synteny, remain open. moreover, few comprehensive studies have been reported for rhizobial genomes. | 2005 | 16229745 |
| identification of quorum-sensing signal molecules and the luxri homologs in fish pathogen edwardsiella tarda. | edwardsiella tarda is a gram-negative bacterium that causes septicaemia in fish and serious damage to the aquaculture industry. the virulence factors of this pathogen and control mechanisms of the expression of virulence genes have not yet been clearly elucidated. a number of gram-negative pathogenic bacteria have a quorum-sensing system. these bacteria produce n-acyl-l-homoserine lactone (ahl) that they use them as a quorum-sensing signal molecule. in this study, we found that e. tarda isolated ... | 2004 | 16233705 |
| insights into genome plasticity and pathogenicity of the plant pathogenic bacterium xanthomonas campestris pv. vesicatoria revealed by the complete genome sequence. | the gram-negative plant-pathogenic bacterium xanthomonas campestris pv. vesicatoria is the causative agent of bacterial spot disease in pepper and tomato plants, which leads to economically important yield losses. this pathosystem has become a well-established model for studying bacterial infection strategies. here, we present the whole-genome sequence of the pepper-pathogenic xanthomonas campestris pv. vesicatoria strain 85-10, which comprises a 5.17-mb circular chromosome and four plasmids. th ... | 2005 | 16237009 |
| the incp island in the genome of brucella suis 1330 was acquired by site-specific integration. | an 18,228-bp region containing open reading frames predicted to be derived from the incp plasmid or phage ancestors is present in the genomes of brucella suis biovars 1 to 4, b. canis, b. neotomae, and strains isolated from marine mammals, but not in b. melitensis, b. abortus, b. ovis, and b. suis biovar 5. the presence of circular excision intermediates and the results of an analysis of sequenced bacterial genomes suggest that the region downstream of the guaa gene is a hotspot for site-specifi ... | 2005 | 16239585 |
| the evolution of microbial phosphonate degradative pathways. | phosphonate utilization by microbes provides a potential source of phosphorus for their growth. homologous genes for both c-p lyase and phosphonatase degradative pathways are distributed in distantly related bacterial species. the phn gene clusters for the c-p lyase pathway show great structural and compositional variation among organisms, but all contain phng-phnm genes that are essential for c-p bond cleavage. in the gamma-proteobacterium erwinia carotovora, genes common to phosphonate biosynt ... | 2005 | 16245012 |
| potato homologs of arabidopsis thaliana genes functional in defense signaling--identification, genetic mapping, and molecular cloning. | defense against pests and pathogens is a fundamental process controlled by similar molecular mechanisms in all flowering plants. using arabidopsis thaliana as a model, steps of the signal transduction pathways that link pathogen recognition to defense activation have been identified and corresponding genes have been characterized. defense signaling (ds) genes are functional candidates for controlling natural quantitative variation of resistance to plant pathogens. nineteen arabidopsis genes oper ... | 2005 | 16255250 |
| isolation and partial characterization of antagonistic peptides produced by paenibacillus sp. strain b2 isolated from the sorghum mycorrhizosphere. | paenibacillus sp. strain b2, isolated from the mycorrhizosphere of sorghum colonized by glomus mosseae, produces an antagonistic factor. this factor has a broad spectrum of activity against gram-positive and gram-negative bacteria and also against fungi. the antagonistic factor was isolated from the bacterial culture medium and purified by cation-exchange, reverse-phase, and size exclusion chromatography. the purified factor could be separated into three active compounds following characterizati ... | 2005 | 16269674 |
| expression of the hypersensitive response-assisting protein in arabidopsis results in harpin-dependent hypersensitive cell death in response to erwinia carotovora. | active defense mechanisms of plants against pathogens often include a rapid plant cell death known as the hypersensitive cell death (hcd). hypersensitive response-assisting protein (hrap) isolated from sweet pepper intensifies the harpin(pss)-mediated hcd. here we demonstrate that constitutive expression of the hrap gene in arabidopsis results in an enhanced disease resistance towards soft rot pathogen, e. carotovora subsp. carotovora. this resistance was due to the induction of hcd since differ ... | 2005 | 16270229 |
| three small rnas jointly ensure secondary metabolism and biocontrol in pseudomonas fluorescens cha0. | in many gram-negative bacteria, the gacs/gaca two-component system positively controls the expression of extracellular products or storage compounds. in the plant-beneficial rhizosphere bacterium pseudomonas fluorescens cha0, the gacs/gaca system is essential for the production of antibiotic compounds and hence for biological control of root-pathogenic fungi. the small (119-nt) rna rsmx discovered in this study, together with rsmy and rsmz, forms a triad of gaca-dependent small rnas, which seque ... | 2005 | 16286659 |
| comparative analysis of two classes of quorum-sensing signaling systems that control production of extracellular proteins and secondary metabolites in erwinia carotovora subspecies. | in erwinia carotovora subspecies, n-acyl homoserine lactone (ahl) controls the expression of various traits, including extracellular enzyme/protein production and pathogenicity. we report here that e. carotovora subspecies possess two classes of quorum-sensing signaling systems defined by the nature of the major ahl analog produced as well as structural and functional characteristics of ahl synthase (ahli) and ahl receptor (expr). class i strains represented by e. carotovora subsp. atroseptica s ... | 2005 | 16291676 |
| identification of erwinia amylovora genes induced during infection of immature pear tissue. | the enterobacterium erwinia amylovora is a devastating plant pathogen causing necrotrophic fire blight disease of apple, pear, and other rosaceous plants. in this study, we used a modified in vivo expression technology system to identify e. amylovora genes that are activated during infection of immature pear tissue, a process that requires the major pathogenicity factors of this organism. we identified 394 unique pear fruit-induced (pfi) genes on the basis of sequence similarity to known genes a ... | 2005 | 16291682 |
| four-helix bundle: a ubiquitous sensory module in prokaryotic signal transduction. | motivation: transmembrane chemoreceptors in escherichia coli utilize ligand-binding domains for detecting various external signals. the structure of this domain in the e.coli aspartate receptor, tar, is known and its signal transduction mechanism is under investigation. current domain models for this important sensory module are inaccurate and, therefore, cannot reveal the distribution of this domain within the current genomic landscape. results: we carried out sensitive and exhaustive psi-blast ... | 2005 | 16306392 |
| the molecular structure and catalytic mechanism of a quorum-quenching n-acyl-l-homoserine lactone hydrolase. | in many gram-negative bacteria, including a number of pathogens such as pseudomonas aeruginosa and erwinia carotovora, virulence factor production and biofilm formation are linked to the quorum-sensing systems that use diffusible n-acyl-l-homoserine lactones (ahls) as intercellular messenger molecules. a number of organisms also contain genes coding for lactonases that hydrolyze ahls into inactive products, thereby blocking the quorum-sensing systems. consequently, these enzymes attract intense ... | 2005 | 16314577 |
| genetic characterization of pseudomonas fluorescens sbw25 rsp gene expression in the phytosphere and in vitro. | the plant-colonizing pseudomonas fluorescens strain sbw25 harbors a gene cluster (rsp) whose products show similarity to type iii protein secretion systems found in plant and animal pathogens. here we report a detailed analysis of the expression and regulation of the p. fluorescens rsp pathway, both in the phytosphere and in vitro. a combination of chromosomally integrated transcriptional reporter fusions, overexpressed regulatory genes, and specific mutants reveal that promoters controlling exp ... | 2005 | 16321952 |
| diversity of carotenoid synthesis gene clusters from environmental enterobacteriaceae strains. | eight enterobacteriaceae strains that produce zeaxanthin and derivatives of this compound were isolated from a variety of environmental samples. phylogenetic analysis showed that these strains grouped with different clusters of erwinia type strains. four strains representing the phylogenetic diversity were chosen for further characterization, which revealed their genetic diversity as well as their biochemical diversity. the carotenoid synthesis gene clusters cloned from the four strains had thre ... | 2005 | 16332796 |
| phage tail-like (high-molecular-weight) bacteriocins of budvicia aquatica and pragia fontium (enterobacteriaceae). | electron microscopic analysis of contractile phage tail-like bacteriocins of three pragia fontium strains and one budvicia aquatica strain was performed. fonticin and aquaticin are remarkably heat sensitive but trypsin resistant. simultaneous production of contractile and flexible phage tail-like bacteriocins in the p. fontium 64613 strain is shown for the first time. | 2005 | 16332902 |
| identification of drosophila gene products required for phagocytosis of candida albicans. | phagocytosis is a highly conserved aspect of innate immunity. we used drosophila melanogaster s2 cells as a model system to study the phagocytosis of candida albicans, the major fungal pathogen of humans, by screening an rnai library representing 7,216 fly genes conserved among metazoans. after rescreening the initial genes identified and eliminating certain classes of housekeeping genes, we identified 184 genes required for efficient phagocytosis of c. albicans. diverse biological processes are ... | 2006 | 16336044 |
| identification of drosophila gene products required for phagocytosis of candida albicans. | phagocytosis is a highly conserved aspect of innate immunity. we used drosophila melanogaster s2 cells as a model system to study the phagocytosis of candida albicans, the major fungal pathogen of humans, by screening an rnai library representing 7,216 fly genes conserved among metazoans. after rescreening the initial genes identified and eliminating certain classes of housekeeping genes, we identified 184 genes required for efficient phagocytosis of c. albicans. diverse biological processes are ... | 2006 | 16336044 |
| conserved and variable functions of the sigmae stress response in related genomes. | bacteria often cope with environmental stress by inducing alternative sigma (sigma) factors, which direct rna polymerase to specific promoters, thereby inducing a set of genes called a regulon to combat the stress. to understand the conserved and organism-specific functions of each sigma, it is necessary to be able to predict their promoters, so that their regulons can be followed across species. however, the variability of promoter sequences and motif spacing makes their prediction difficult. w ... | 2006 | 16336047 |
| conserved and variable functions of the sigmae stress response in related genomes. | bacteria often cope with environmental stress by inducing alternative sigma (sigma) factors, which direct rna polymerase to specific promoters, thereby inducing a set of genes called a regulon to combat the stress. to understand the conserved and organism-specific functions of each sigma, it is necessary to be able to predict their promoters, so that their regulons can be followed across species. however, the variability of promoter sequences and motif spacing makes their prediction difficult. w ... | 2006 | 16336047 |
| activation of defense responses in chinese cabbage by a nonhost pathogen, pseudomonas syringae pv. tomato. | pseudomonas syringae pv. tomato (pst) causes a bacterial speck disease in tomato and arabidopsis. in chinese cabbage, in which host-pathogen interactions are not well understood, pst does not cause disease but rather elicits a hypersensitive response. pst induces localized cell death and h2o2 accumulation, a typical hypersensitive response, in infiltrated cabbage leaves. pre-inoculation with pst was found to induce resistance to erwinia carotovora subsp. carotovora, a pathogen that causes soft r ... | 2005 | 16336791 |
| alternative sigma factors and their roles in bacterial virulence. | sigma factors provide promoter recognition specificity to rna polymerase holoenzyme, contribute to dna strand separation, and then dissociate from the core enzyme following transcription initiation. as the regulon of a single sigma factor can be composed of hundreds of genes, sigma factors can provide effective mechanisms for simultaneously regulating expression of large numbers of prokaryotic genes. one newly emerging field is identification of the specific roles of alternative sigma factors in ... | 2005 | 16339734 |
| pectinmethylesterase from the rice weevil, sitophilus oryzae: cdna isolation and sequencing, genetic origin, and expression of the recombinant enzyme. | a cdna clone encoding pectinmethylesterase of the rice weevil, sitophilus oryzae (l.) has been isolated and sequenced. the cdna clone was expressed in cultured insect cells and active pectinmethylesterase was purified from the culture medium, thus confirming that the cdna encodes pectinmethylesterase. in situ hybridization indicated that the enzyme's transcript was present in the midgut. weevils treated with tetracycline so that they lack genes of known symbiotic organisms still contained the pe ... | 2005 | 16341253 |
| antagonism of lactic acid bacteria against phytopathogenic bacteria. | a variety of lactic acid bacteria, isolated from plant surfaces and plant-associated products, were found to be antagonistic to test strains of the phytopathogens xanthomonas campestris, erwinia carotovora, and pseudomonas syringae. effective "in vitro" inhibition was found both on agar plates and in broth cultures. in pot trials, treatment of bean plants with a lactobacillus plantarum strain before inoculation with p. syringae caused a significant reduction of the disease incidence. | 1986 | 16347150 |
| a rapid procedure for purifying pectate lyase from erwinia carotovora based on substrate affinity. | to purify pectate lyase produced by erwinia carotovora subsp. carotovora, we used the supernatant from 48-h-old cultures grown in broth containing sodium polypectate and yeast extract. the supernatant was combined with the enzyme substrates sodium polypectate and polygalacturonic acid, which were then precipitated with cacl(2). after the precipitate was washed, pectate lyase was eluted with 1.0 m nacl. | 1987 | 16347348 |
| fermentation of d-xylose and l-arabinose to ethanol by erwinia chrysanthemi. | erwinia spp. are gram-negative facultative anaerobes within the family enterobacteriacae which possess several desirable traits for the conversion of pentose sugars to ethanol, such as the ability to ferment a broad range of carbohydrates and the ease with which they can be genetically modified. twenty-eight strains of erwinia carotovora and e. chrysanthemi were screened for the ability to ferment d-xylose to ethanol. e. chrysanthemi b374 was chosen for further study on the basis of its superior ... | 1987 | 16347426 |
| role of antibiosis in competition of erwinia strains in potato infection courts. | erwinia carotovora subsp. betavasculorum strains produced a bactericidal antibiotic in vitro that inhibited a wide spectrum of gram-negative and gram-positive bacteria. the optimum temperature for production was 24 degrees c, and the addition of glycerol to culture media enhanced antibiotic production. antibiotic production by these strains in the infection court of potato was the principal determinant enabling it to gain ascendancy over competing antibiotic-sensitive erwinia carotovora subsp. c ... | 1988 | 16347633 |
| genetically engineered erwinia carotovora in aquatic microcosms: survival and effects on functional groups of indigenous bacteria. | the survival of genetically engineered erwinia carotovora l-864, with a kanamycin resistance gene inserted in its chromosome, was monitored in the water and sediment of aquatic microcosms. the density of genetically engineered and wild-type e. carotovora strains declined at the same rate, falling in 32 days below the level of detection by viable counts. we examined the impact of the addition of genetically engineered and wild-type strains on indigenous bacteria belonging to specific functional g ... | 1989 | 16347942 |
| genetically engineered erwinia carotovora: survival, intraspecific competition, and effects upon selected bacterial genera. | environmental use of genetically engineered microorganisms has raised concerns about potential ecological impact. this research evaluated the survival, competitiveness, and effects upon selected bacterial genera of wild-type and genetically engineered erwinia carotovora subsp. carotovora to ascertain if differences between the wild-type and genetically engineered strains exist in soil microcosms. the engineered strain contained a chromosomally inserted gene for kanamycin resistance. no significa ... | 1990 | 16348212 |
| anaerobic nitrate respiration by erwinia carotovora subsp. atroseptica during potato tuber invasion. | the in planta induction of anaerobic nitrate respiration by erwinia carotovora subsp. atroseptica in relation to the in situ oxygen status in soft rotting potato tubers has been investigated. in vitro experiments have shown that nitrate was required for the induction of respiratory nitrate reductase activity in e. carotovora. in addition, oxygen was found to repress this activity. expression of respiratory nitrate reductase was found in e. carotovora cells extracted from soft rotting potato tube ... | 1993 | 16349082 |
| two genomic regions involved in catechol siderophore production by erwinia carotovora. | two regions involved in catechol biosynthesis (cbs) of erwinia carotovora w3c105 were cloned by functional complementation of escherichia coli mutants that were deficient in the biosynthesis of the catechol siderophore enterobactin (ent). a 4.3-kb region of genomic dna of e. carotovora complemented the entb402 mutation of e. coli. a second genomic region of 12.8 kb complemented entd, entc147, ente405, and enta403 mutations of e. coli. although functions encoded by catechol biosynthesis genes (cb ... | 1994 | 16349193 |
| characterization of monoclonal antibodies specific for erwinia carotovora subsp. atroseptica and comparison of serological methods for its sensitive detection on potato tubers. | seven monoclonal antibodies (mabs) to erwinia carotovora subsp. atroseptica have been produced. one, called 4g4, reacted with high specificity for serogroup i of e. carotovora subsp. atroseptica, the most common serogroup on potato tubers in different serological assays. eighty-six strains belonging to different e. carotovora subsp. atroseptica serogroups were assayed. some strains of serogroup xxii also reacted positively. no cross-reactions were observed against other species of plant pathogen ... | 1994 | 16349293 |
| derivation of mutants of erwinia carotovora subsp. betavasculorum deficient in export of pectolytic enzymes with potential for biological control of potato soft rot. | erwinia carotovora subsp. betavasculorum ecb168 produces an antibiotic(s) that suppresses growth of the related bacterium erwinia carotovora subsp. carotovora in culture and in wounds of potato tubers. strain ecb168 also produces and secretes pectolytic enzymes and causes a vascular necrosis and root rot of sugar beet. genes (out) involved in secretion of pectolytic enzymes by ecb168 were localized to two hindiii fragments (8.5 and 10.5 kb) of ecb168 genomic dna by hybridization to the cloned ou ... | 1994 | 16349316 |
| role of salmonella enterica serovar typhimurium two-component system prea/preb in modulating pmra-regulated gene transcription. | the pmra/pmrb two-component system encoded by the pmrcab operon regulates the modification of salmonella enterica serovar typhimurium lipopolysaccharide leading to polymyxin b resistance. pmra and phop are the only known activators of pmrcab. a transposon mutagenesis screen for additional regulators of a pmrc::mudj fusion led to the identification of a two-component system, termed prea/preb (pmrcab regulators a and b), that controls the transcription of the pmrcab operon in response to unknown s ... | 2006 | 16352830 |
| [enhanced resistance to phytopathogenic bacteria in transgenic tobacco plants with synthetic gene of antimicrobial peptide cecropin p1]. | plasmids with a synthetic gene of the mammalian antimicrobial peptide cecropin p1 (cecp1) controlled by the constitutive promoter 35s rna of cauliflower mosaic virus were constructed. agrobacterial transformation of tobacco plants was conducted using the obtained recombinant binary vector. the presence of gene cecp1 in the plant genome was confirmed by pcr. the expression of gene cecp1 in transgenic plants was shown by northern blot analysis. the obtained transgenic plants exhibit enhanced resis ... | 2005 | 16358711 |
| identification of the central quorum sensing regulator of virulence in the enteric phytopathogen, erwinia carotovora: the virr repressor. | in the gram-negative phytopathogen, erwinia carotovora ssp. atroseptica (eca) virulence depends on the production of a n-(3-oxohexanoyl)-l-homoserine lactone (ohhl) quorum sensing (qs) signal. this work identifies the elusive 'missing link' between qs and virulence in erwinia. we have identified and characterized a novel regulator of virulence, virr, in eca and show that a virr mutation completely restores virulence factor production to an eca mutant unable to synthesize ohhl. this effect of the ... | 2006 | 16359322 |
| the lpf gene cluster for long polar fimbriae is not involved in adherence of enteropathogenic escherichia coli or virulence of citrobacter rodentium. | using the enteropathogenic escherichia coli (epec) genome sequence, we found that epec e2348/69 has an lpfabcde gene cluster homologous (about 60% identical at the protein level) to the salmonella long polar fimbria (lpf) operon. to determine whether this operon is essential for adherence, the lpfabcd(e2)(3) genes were deleted from epec strain e2348/69 by allelic exchange. analysis of the resulting epecdeltalpfabcd(e23) strain showed no change in adherence to hela cells or to human intestinal bi ... | 2006 | 16368980 |
| the genome sequence of methanosphaera stadtmanae reveals why this human intestinal archaeon is restricted to methanol and h2 for methane formation and atp synthesis. | methanosphaera stadtmanae has the most restricted energy metabolism of all methanogenic archaea. this human intestinal inhabitant can generate methane only by reduction of methanol with h2 and is dependent on acetate as a carbon source. we report here the genome sequence of m. stadtmanae, which was found to be composed of 1,767,403 bp with an average g+c content of 28% and to harbor only 1,534 protein-encoding sequences (cds). the genome lacks 37 cds present in the genomes of all other methanoge ... | 2006 | 16385054 |