Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| 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 |
| 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 |
| 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 |
| posttranscriptional repression of gacs/gaca-controlled genes by the rna-binding protein rsme acting together with rsma in the biocontrol strain pseudomonas fluorescens cha0. | in the plant-beneficial soil bacterium pseudomonas fluorescens cha0, the production of biocontrol factors (antifungal secondary metabolites and exoenzymes) is controlled at a posttranscriptional level by the gacs/gaca signal transduction pathway involving rna-binding protein rsma as a key regulatory element. this protein is assumed to bind to the ribosome-binding site of target mrnas and to block their translation. rsma-mediated repression is relieved at the end of exponential growth by two gacs ... | 2005 | 15601712 |
| 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 |
| 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 |
| interactions between oral bacteria: inhibition of streptococcus mutans bacteriocin production by streptococcus gordonii. | streptococcus mutans has been recognized as an important etiological agent in human dental caries. some strains of s. mutans also produce bacteriocins. in this study, we sought to demonstrate that bacteriocin production by s. mutans strains gs5 and bm71 was mediated by quorum sensing, which is dependent on a competence-stimulating peptide (csp) signaling system encoded by the com genes. we also demonstrated that interactions with some other oral streptococci interfered with s. mutans bacteriocin ... | 2005 | 15640209 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| crystallization and preliminary crystallographic analysis of l-asparaginase from erwinia carotovora. | bacterial l-asparaginases have been used as therapeutic agents in the treatment of acute childhood lymphoblastic leukaemia for over 30 y. however, their use is limited owing to the glutaminase activity of the administered enzymes, which results in serious side effects. in contrast, l-asparaginase from erwinia carotovora exhibits low glutaminase activity at physiological concentrations of l-asparagine and l-glutamine in the blood. recombinant er. carotovora l-asparaginase was crystallized in the ... | 2005 | 16511054 |
| 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 |
| 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 |
| health considerations regarding horizontal transfer of microbial transgenes present in genetically modified crops. | the potential effects of horizontal gene transfer on human health are an important item in the safety assessment of genetically modified organisms. horizontal gene transfer from genetically modified crops to gut microflora most likely occurs with transgenes of microbial origin. the characteristics of microbial transgenes other than antibiotic-resistance genes in market-approved genetically modified crops are reviewed. these characteristics include the microbial source, natural function, function ... | 2005 | 16489267 |
| 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 |
| 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 |
| harnessing natural diversity to probe metabolic pathways. | analyses of cellular processes in the yeast saccharomyces cerevisiae rely primarily upon a small number of highly domesticated laboratory strains, leaving the extensive natural genetic diversity of the model organism largely unexplored and unexploited. we asked if this diversity could be used to enrich our understanding of basic biological processes. as a test case, we examined a simple trait: the utilization of di/tripeptides as nitrogen sources. the capacity to import small peptides is likely ... | 2005 | 16429164 |
| 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 |
| 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 |
| 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 |
| 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 |
| evaluation of the antimicrobial activities of plant oxylipins supports their involvement in defense against pathogens. | plant oxylipins are a large family of metabolites derived from polyunsaturated fatty acids. the characterization of mutants or transgenic plants affected in the biosynthesis or perception of oxylipins has recently emphasized the role of the so-called oxylipin pathway in plant defense against pests and pathogens. in this context, presumed functions of oxylipins include direct antimicrobial effect, stimulation of plant defense gene expression, and regulation of plant cell death. however, the preci ... | 2005 | 16299186 |
| the net of life: reconstructing the microbial phylogenetic network. | it has previously been suggested that the phylogeny of microbial species might be better described as a network containing vertical and horizontal gene transfer (hgt) events. yet, all phylogenetic reconstructions so far have presented microbial trees rather than networks. here, we present a first attempt to reconstruct such an evolutionary network, which we term the "net of life". we use available tree reconstruction methods to infer vertical inheritance, and use an ancestral state inference alg ... | 2005 | 15965028 |
| drastic--insights: querying information in a plant gene expression database. | drastic--database resource for the analysis of signal transduction in cells (http://www.drastic.org.uk/) has been created as a first step towards a data-based approach for constructing signal transduction pathways. drastic is a relational database of plant expressed sequence tags and genes up- or down-regulated in response to various pathogens, chemical exposure or other treatments such as drought, salt and low temperature. more than 17700 records have been obtained from 306 treatments affecting ... | 2005 | 16381965 |
| drastic--insights: querying information in a plant gene expression database. | drastic--database resource for the analysis of signal transduction in cells (http://www.drastic.org.uk/) has been created as a first step towards a data-based approach for constructing signal transduction pathways. drastic is a relational database of plant expressed sequence tags and genes up- or down-regulated in response to various pathogens, chemical exposure or other treatments such as drought, salt and low temperature. more than 17700 records have been obtained from 306 treatments affecting ... | 2005 | 16381965 |
| comparative genomic analyses of the bacterial phosphotransferase system. | we report analyses of 202 fully sequenced genomes for homologues of known protein constituents of the bacterial phosphoenolpyruvate-dependent phosphotransferase system (pts). these included 174 bacterial, 19 archaeal, and 9 eukaryotic genomes. homologues of pts proteins were not identified in archaea or eukaryotes, showing that the horizontal transfer of genes encoding pts proteins has not occurred between the three domains of life. of the 174 bacterial genomes (136 bacterial species) analyzed, ... | 2005 | 16339738 |
| the 2-hydroxycarboxylate transporter family: physiology, structure, and mechanism. | the 2-hydroxycarboxylate transporter family is a family of secondary transporters found exclusively in the bacterial kingdom. they function in the metabolism of the di- and tricarboxylates malate and citrate, mostly in fermentative pathways involving decarboxylation of malate or oxaloacetate. these pathways are found in the class bacillales of the low-cg gram-positive bacteria and in the gamma subdivision of the proteobacteria. the pathways have evolved into a remarkable diversity in terms of th ... | 2005 | 16339740 |
| improved assessment of denitrifying, n2-fixing, and total-community bacteria by terminal restriction fragment length polymorphism analysis using multiple restriction enzymes. | a database of terminal restriction fragments (trfs) of the 16s rrna gene was set up utilizing 13 restriction enzymes and 17,327 genbank sequences. a computer program, termed trefid, was developed to allow identification of any of these 17,327 sequences by means of polygons generated from the specific trfs of each bacterium. the trefid program complements and exceeds in its data content the web-based phylogenetic assignment tool recently described by a. d. kent, d. j. smith, b. j. benson, and e. ... | 2005 | 15812035 |
| unraveling the secret lives of bacteria: use of in vivo expression technology and differential fluorescence induction promoter traps as tools for exploring niche-specific gene expression. | a major challenge for microbiologists is to elucidate the strategies deployed by microorganisms to adapt to and thrive in highly complex and dynamic environments. in vitro studies, including those monitoring genomewide changes, have proven their value, but they can, at best, mimic only a subset of the ensemble of abiotic and biotic stimuli that microorganisms experience in their natural habitats. the widely used gene-to-phenotype approach involves the identification of altered niche-related phen ... | 2005 | 15944455 |
| decoding microbial chatter: cell-cell communication in bacteria. | 2005 | 16077095 | |
| comparative and evolutionary analysis of the bacterial homologous recombination systems. | homologous recombination is a housekeeping process involved in the maintenance of chromosome integrity and generation of genetic variability. although detailed biochemical studies have described the mechanism of action of its components in model organisms, there is no recent extensive assessment of this knowledge, using comparative genomics and taking advantage of available experimental data on recombination. using comparative genomics, we assessed the diversity of recombination processes among ... | 2005 | 16132081 |
| a relative-entropy algorithm for genomic fingerprinting captures host-phage similarities. | the degeneracy of codons allows a multitude of possible sequences to code for the same protein. hidden within the particular choice of sequence for each organism are over 100 previously undiscovered biologically significant, short oligonucleotides (length, 2 to 7 nucleotides). we present an information-theoretic algorithm that finds these novel signals. applying this algorithm to the 209 sequenced bacterial genomes in the ncbi database, we determine a set of oligonucleotides for each bacterium w ... | 2005 | 16321941 |
| new frontiers in immunology. workshop on the road ahead: future directions in fundamental and clinical immunology. | 2005 | 15976818 | |
| use of plant growth-promoting bacteria for biocontrol of plant diseases: principles, mechanisms of action, and future prospects. | 2005 | 16151072 | |
| multiple defence signals induced by erwinia carotovora ssp. carotovora elicitors in potato. | summary signal pathways involved in solanum tuberosum-erwinia carotovora ssp. carotovora(scc3193) interaction were characterized. to this end, the concentration of several signal molecules implicated in plant defence such as ethylene (et), jasmonates (ja) and salicylic acid (sa) were measured in potato plants treated by cell-free culture filtrates (cf) from e. c. carotovora(scc3193). furthermore, the presence of other potential signalling compounds such as cinnamic acid (ca) and related aromatic ... | 2005 | 20565678 |
| genetic and proteomic analysis of the role of luxs in the enteric phytopathogen, erwinia carotovora. | summary erwinia carotovora is a gram-negative phytopathogen that is an important cause of soft rot disease, including stem and tuber rot in potatoes. quorum sensing is the process by which bacteria detect their population density and regulate gene expression accordingly. quorum sensing, an important example of intercellular communication, involves the production and detection of chemical signal molecules. the enzyme luxs is responsible for the production of autoinducer-2 (ai-2), a molecule that ... | 2006 | 20507426 |
| multiple determinants influence root colonization and induction of induced systemic resistance by pseudomonas chlororaphis o6. | summary colonization of the roots of tobacco by pseudomonas chlororaphis o6 induces systemic resistance to the soft-rot pathogen, erwinia carotovora ssp. carotovara scc1. a screen of the transposon mutants of p. chlororaphis o6 showed mutants with about a fivefold reduction in ability to induce systemic resistance to the soft-rot disease. these mutations disrupted genes involved in diverse functions: a methyl-accepting chemotaxis protein, biosynthesis of purines, phospholipase c, transport of br ... | 2006 | 20507461 |
| a methodology to detect and quantify five pathogens causing potato tuber decay using real-time quantitative polymerase chain reaction. | abstract late blight (phytophthora infestans), pink rot (phytophthora erythroseptica), leak (pythium ultimum), dry rot (fusarium sambucinum), and soft rot (erwinia carotovora subsp. carotovora and subsp. atroseptica) are particularly damaging diseases of stored potato tubers worldwide. in this study, we present a methodology to detect and quantify the causal agents of the five aforementioned diseases from whole potato tubers, using real-time quantitative-polymerase chain reaction. six primer pai ... | 2006 | 18944060 |
| messing with bacterial quorum sensing. | quorum sensing is widely recognized as an efficient mechanism to regulate expression of specific genes responsible for communal behavior in bacteria. several bacterial phenotypes essential for the successful establishment of symbiotic, pathogenic, or commensal relationships with eukaryotic hosts, including motility, exopolysaccharide production, biofilm formation, and toxin production, are often regulated by quorum sensing. interestingly, eukaryotes produce quorum-sensing-interfering (qsi) compo ... | 2006 | 17158701 |
| diverse bacterial genomes encode an operon of two genes, one of which is an unusual class-i release factor that potentially recognizes atypical mrna signals other than normal stop codons. | while all codons that specify amino acids are universally recognized by trna molecules, codons signaling termination of translation are recognized by proteins known as class-i release factors (rf). in most eukaryotes and archaea a single rf accomplishes termination at all three stop codons. in most bacteria, there are two rfs with overlapping specificity, rf1 recognizes ua(a/g) and rf2 recognizes u(a/g)a. | 2006 | 16970810 |
| identification of a gene encoding a functional reverse transcriptase within a highly variable locus in the p2-like coliphages. | the p2-like coliphages are highly similar; the structural genes show at least 96% identity. however, at two loci they have genes believed to be horizontally transferred. we show that the genetic content at the second loci, the to region, contains six completely different sequences with high at contents and with different open reading frames. the product of one of them exhibits reverse transcriptase activity and blocks infection of phage t5. | 2006 | 16452449 |
| asap: a resource for annotating, curating, comparing, and disseminating genomic data. | asap is a comprehensive web-based system for community genome annotation and analysis. asap is being used for a large-scale effort to augment and curate annotations for genomes of enterobacterial pathogens and for additional genome sequences. new tools, such as the genome alignment program mauve, have been incorporated into asap in order to improve display and analysis of related genomes. recent improvements to the database and challenges for future development of the system are discussed. asap ... | 2006 | 16381899 |
| asap: a resource for annotating, curating, comparing, and disseminating genomic data. | asap is a comprehensive web-based system for community genome annotation and analysis. asap is being used for a large-scale effort to augment and curate annotations for genomes of enterobacterial pathogens and for additional genome sequences. new tools, such as the genome alignment program mauve, have been incorporated into asap in order to improve display and analysis of related genomes. recent improvements to the database and challenges for future development of the system are discussed. asap ... | 2006 | 16381899 |
| dispersal and regulation of an adaptive mutagenesis cassette in the bacteria domain. | recently, a multiple gene cassette with mutagenic translation synthesis activity was identified and shown to be under lexa regulation in several proteobacteria species. in this work, we have traced down instances of this multiple gene cassette across the bacteria domain. phylogenetic analyses show that this cassette has undergone several reorganizations since its inception in the actinobacteria, and that it has dispersed across the bacterial domain through a combination of vertical inheritance, ... | 2006 | 16407325 |
| how phosphotransferase system-related protein phosphorylation regulates carbohydrate metabolism in bacteria. | the phosphoenolpyruvate(pep):carbohydrate phosphotransferase system (pts) is found only in bacteria, where it catalyzes the transport and phosphorylation of numerous monosaccharides, disaccharides, amino sugars, polyols, and other sugar derivatives. to carry out its catalytic function in sugar transport and phosphorylation, the pts uses pep as an energy source and phosphoryl donor. the phosphoryl group of pep is usually transferred via four distinct proteins (domains) to the transported sugar bo ... | 2006 | 17158705 |
| a database of bacterial lipoproteins (dolop) with functional assignments to predicted lipoproteins. | lipid modification of the n-terminal cys residue (n-acyl-s-diacylglyceryl-cys) has been found to be an essential, ubiquitous, and unique bacterial posttranslational modification. such a modification allows anchoring of even highly hydrophilic proteins to the membrane which carry out a variety of functions important for bacteria, including pathogenesis. hence, being able to identify such proteins is of great value. to this end, we have created a comprehensive database of bacterial lipoproteins, c ... | 2006 | 16585737 |
| gata factors participate in tissue-specific immune responses in drosophila larvae. | drosophila responds to infection by producing a broad range of antimicrobial agents in the fat body and more restricted responses in tissues such as the gut, trachea, and malpighian tubules. the regulation of antimicrobial genes in larval fat depends on linked rel/nf-kappab and gata binding sites. serpent functions as the major gata transcription factor in the larval fat body. however, the transcriptional regulation of other tissue-specific responses is less well understood. here, we present evi ... | 2006 | 17032752 |
| downregulation of the drosophila immune response by peptidoglycan-recognition proteins sc1 and sc2. | peptidoglycan-recognition proteins (pgrps) are evolutionarily conserved molecules that are structurally related to bacterial amidases. several drosophila pgrps have lost this enzymatic activity and serve as microbe sensors through peptidoglycan recognition. other pgrp family members, such as drosophila pgrp-sc1 or mammalian pgrp-l, have conserved the amidase function and are able to cleave peptidoglycan in vitro. however, the contribution of these amidase pgrps to host defense in vivo has remain ... | 2006 | 16518472 |
| cooperative control of drosophila immune responses by the jnk and nf-kappab signaling pathways. | jun n-terminal kinase (jnk) signaling is a highly conserved pathway that controls both cytoskeletal remodeling and transcriptional regulation in response to a wide variety of signals. despite the importance of jnk in the mammalian immune response, and various suggestions of its importance in drosophila immunity, the actual contribution of jnk signaling in the drosophila immune response has been unclear. drosophila tak1 has been implicated in the nf-kappab/relish-mediated activation of antimicrob ... | 2006 | 16763552 |
| stringent and relaxed recognition of orit by related systems for plasmid mobilization: implications for horizontal gene transfer. | the plasmids r1162 and psc101 have origins of conjugative transfer (orits) and corresponding relaxases that are closely related. the orits are made up of a highly conserved core, where dna is cleaved by the relaxase prior to transfer, and an inverted repeat that differs in size and sequence. we show that in each case the seven base pairs adjacent to the core and within one arm of the inverted repeat are sufficient to determine specificity. within this dna there are three at base pairs located 4 ... | 2006 | 16385040 |
| an essential complementary role of nf-kappab pathway to microbicidal oxidants in drosophila gut immunity. | in the drosophila gut, reactive oxygen species (ros)-dependent immunity is critical to host survival. this is in contrast to the nf-kappab pathway whose physiological function in the microbe-laden epithelia has yet to be convincingly demonstrated despite playing a critical role during systemic infections. we used a novel in vivo approach to reveal the physiological role of gut nf-kappab/antimicrobial peptide (amp) system, which has been 'masked' in the presence of the dominant intestinal ros-dep ... | 2006 | 16858400 |
| bacterial elicitation and evasion of plant innate immunity. | recent research on plant responses to bacterial attack has identified extracellular and intracellular host receptors that recognize conserved pathogen-associated molecular patterns and more specialized virulence proteins, respectively. these findings have shed light on our understanding of the molecular mechanisms by which bacteria elicit host defences and how pathogens have evolved to evade or suppress these defences. | 2006 | 16936700 |
| extratrain: a database of extragenic regions and transcriptional information in prokaryotic organisms. | transcriptional regulation processes are the principal mechanisms of adaptation in prokaryotes. in these processes, the regulatory proteins and the regulatory dna signals located in extragenic regions are the key elements involved. as all extragenic spaces are putative regulatory regions, extratrain covers all extragenic regions of available genomes and regulatory proteins from bacteria and archaea included in the uniprot database. | 2006 | 16539733 |
| the drosophila inhibitor of apoptosis protein diap2 functions in innate immunity and is essential to resist gram-negative bacterial infection. | the founding member of the inhibitor of apoptosis protein (iap) family was originally identified as a cell death inhibitor. however, recent evidence suggests that iaps are multifunctional signaling devices that influence diverse biological processes. to investigate the in vivo function of drosophila melanogaster iap2, we have generated diap2 null alleles. diap2 mutant animals develop normally and are fully viable, suggesting that diap2 is dispensable for proper development. however, these animal ... | 2006 | 16894030 |
| bacterial conversations: talking, listening and eavesdropping. a nerc discussion meeting held at the royal society on 7 december 2005. | 2006 | 16849274 | |
| the rcs phosphorelay system is specific to enteric pathogens/commensals and activates ydei, a gene important for persistent salmonella infection of mice. | bacteria utilize phosphorelay systems to respond to environmental or intracellular stimuli. salmonella enterica encodes a four-step phosphorelay system that involves two sensor kinase proteins, rcsc and rcsd, and a response regulator, rcsb. the physiological stimulus for rcs phosphorelay activation is unknown; however, rcs-regulated genes can be induced in vitro by osmotic shock, low temperature and antimicrobial peptide exposure. in this report we investigate the role of the rcs pathway using p ... | 2006 | 17010160 |
| within-species flagellin polymorphism in xanthomonas campestris pv campestris and its impact on elicitation of arabidopsis flagellin sensing2-dependent defenses. | bacterial flagellins have been portrayed as a relatively invariant pathogen-associated molecular pattern. we have found within-species, within-pathovar variation for defense-eliciting activity of flagellins among xanthomonas campestris pv campestris (xcc) strains. arabidopsis thaliana flagellin sensing2 (fls2), a transmembrane leucine-rich repeat kinase, confers flagellin responsiveness. the flg22 region was the only xcc flagellin region responsible for detectable elicitation of arabidopsis defe ... | 2006 | 16461584 |
| structural organization and functional properties of miniature dna insertion sequences in yersiniae. | ypals (yersinia palindromic sequences) are miniature dna insertions scattered along the chromosomes of yersiniae. the spread of these intergenic repeats likely occurred via transposition, as suggested by the presence of target site duplications at their termini and the identification of syntenic chromosomal regions which differ in the presence/absence of ypal dna among yersinia strains. ypals tend to be inserted closely downstream from the stop codon of flanking genes, and many ypal targets over ... | 2006 | 16963573 |
| the cation-responsive protein nhar of escherichia coli activates pgaabcd transcription, required for production of the biofilm adhesin poly-beta-1,6-n-acetyl-d-glucosamine. | the pgaabcd operon of escherichia coli is required for production of the biofilm adhesin poly-beta-1,6-n-acetyl-d-glucosamine (pga). we establish here that nhar, a dna-binding protein of the lysr family of transcriptional regulators, activates transcription of this operon. disruption of the nhar gene decreased biofilm formation without affecting planktonic growth. pga production was undetectable in an nhar mutant strain. expression of a pgaa'-'lacz translational fusion was induced by nacl and al ... | 2006 | 16997959 |
| biological characterization of white line-inducing principle (wlip) produced by pseudomonas reactans ncppb1311. | the biological activities of the lipodepsipeptides (ldp) white line-inducing principle (wlip), produced by pseudomonas reactans ncppb1311, and tolaasin i, produced by r tolaasii ncppb2192, were compared. antimicrobial assays showed that both ldp inhibited the growth of fungi-including the cultivated mushrooms agaricus bisporus, lentinus edodes, and pleurotus spp.--chromista, and gram-positive bacteria. assays of the two ldp on blocks of agaricus bisporus showed their capacity to alter the mushro ... | 2006 | 17022175 |
| two-dimensional fluorescence difference gel electrophoresis for comparative proteomics profiling. | quantitative proteomics is the workhorse of the modern proteomics initiative. the gel-based and mudpit approaches have facilitated vital advances in the measurement of protein expression alterations in normal and disease phenotypic states. the methodological advance in two-dimensional gel electrophoresis (2dge) has been the multiplexing fluorescent two-dimensional fluorescence difference gel electrophoresis (2d-dige). 2d-dige is based on direct labeling of lysine groups on proteins with cyanine ... | 2006 | 17487156 |
| prevalence of local immune response against oral infection in a drosophila/pseudomonas infection model. | pathogens have developed multiple strategies that allow them to exploit host resources and resist the immune response. to study how drosophila flies deal with infectious diseases in a natural context, we investigated the interactions between drosophila and a newly identified entomopathogen, pseudomonas entomophila. flies orally infected with p. entomophila rapidly succumb despite the induction of both local and systemic immune responses, indicating that this bacterium has developed specific stra ... | 2006 | 16789834 |
| asparaginase (native asnase or pegylated asnase) in the treatment of acute lymphoblastic leukemia. | the discovery of the tumor-inhibitory properties of asparaginase (asnase) began in the early 1950s with the observation that guinea pig serum-treated lymphoma-bearing mice underwent rapid and often complete regression. about 4000 cases of acute lymphoblastic leukemia (all) are diagnosed very year in the us and many more through out the world. the majority of these cases are in children and young adults, making all the most common form of malignancy in these age groups. the treatment protocols of ... | 2006 | 17717965 |
| two gaca-dependent small rnas modulate the quorum-sensing response in pseudomonas aeruginosa. | in pseudomonas aeruginosa, the gacs/gaca two-component system positively controls the quorum-sensing machinery and the expression of extracellular products via two small regulatory rnas, rsmy and rsmz. an rsmy rsmz double mutant and a gaca mutant were similarly impaired in the synthesis of the quorum-sensing signal n-butanoyl-homoserine lactone, the disulfide bond-forming enzyme dsba, and the exoproducts hydrogen cyanide, pyocyanin, elastase, chitinase (chic), and chitin-binding protein (cbpd). ... | 2006 | 16885472 |
| genetic analysis of the requirement for flp-2, tadv, and rcpb in actinobacillus actinomycetemcomitans biofilm formation. | the tad locus of actinobacillus actinomycetemcomitans encodes a molecular transport system required for tenacious, nonspecific adherence to surfaces and formation of extremely strong biofilms. this locus is dedicated to the biogenesis of flp pili, which are required for colonization and virulence. we have previously shown that 11 of the 14 tad locus genes are required for adherence and flp pilus production. here, we present genetic and phylogenetic analyses of flp-2, tadv, and rcpb genes in biof ... | 2006 | 16923904 |
| genomic analysis of carbon source metabolism of shewanella oneidensis mr-1: predictions versus experiments. | genomic sequences have been used to find the genetic foundation for carbon source metabolism in shewanella oneidensis mr-1. annotated s. oneidensis mr-1 gene products were examined for their sequence similarity to enzymes participating in pathways for utilization of carbon and energy as described in the biocyc database (http://www.biocyc.org/) or in the primary literature. a picture emerges that relegates five- and six-carbon sugars to minor roles as carbon sources, whereas multiple pathways for ... | 2006 | 16788168 |
| cloning, crystallization and preliminary x-ray study of xc1258, a cn-hydrolase superfamily protein from xanthomonas campestris. | cn-hydrolase superfamily proteins are involved in a wide variety of non-peptide carbon-nitrogen hydrolysis reactions, producing some important natural products such as auxin, biotin, precursors of antibiotics etc. these reactions all involve attack on a cyano or carbonyl carbon by a conserved novel catalytic triad glu-lys-cys through a thiol acylenzyme intermediate. however, classification into the cn-hydrolase superfamily based on sequence similarity alone is not straightforward and further str ... | 2006 | 17012795 |
| transcriptional analysis of the reca gene of streptococcus thermophilus. | reca is a highly conserved prokaryotic protein that not only plays several important roles connected to dna metabolism but also affects the cell response to various stress conditions. while reca is highly conserved, the mechanism of transcriptional regulation of its structural gene is less conserved. in escherichia coli the lexa protein acts as a reca repressor and is able, in response to dna damage, of reca-promoted self-cleavage, thus allowing reca transcription. the lexa paradigm, although co ... | 2006 | 16972988 |
| 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 |
| global gene expression analysis of the heat shock response in the phytopathogen xylella fastidiosa. | xylella fastidiosa is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. although different strains have been studied, little is known about x. fastidiosa stress responses. one of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. to investigate x. fastidio ... | 2006 | 16885450 |
| characterization of the biosynthetic pathway of glucosylglycerate in the archaeon methanococcoides burtonii. | the pathway for the synthesis of the organic solute glucosylglycerate (gg) is proposed based on the activities of the recombinant glucosyl-3-phosphoglycerate synthase (gpgs) and glucosyl-3-phosphoglycerate phosphatase (gpgp) from methanococcoides burtonii. a mannosyl-3-phosphoglycerate phosphatase gene homologue (mpgp) was found in the genome of m. burtonii (http://www.jgi.doe.gov), but an mpgs gene coding for mannosyl-3-phosphoglycerate synthase (mpgs) was absent. the gene upstream of the mpgp ... | 2006 | 16428406 |
| early responsive to dehydration 15, a negative regulator of abscisic acid responses in arabidopsis. | early responsive to dehydration 15 (erd15) is rapidly induced in response to various abiotic and biotic stress stimuli in arabidopsis (arabidopsis thaliana). modulation of erd15 levels by overexpression or rnai silencing altered the responsiveness of the transgenic plants to the phytohormone abscisic acid (aba). overexpression of erd15 reduced the aba sensitivity of arabidopsis manifested in decreased drought tolerance and in impaired ability of the plants to increase their freezing tolerance in ... | 2006 | 17056758 |
| active-site residues in the type iv prepilin peptidase homologue pibd from the archaeon sulfolobus solfataricus. | archaeal preflagellin peptidases and bacterial type iv prepilin peptidases belong to a family of aspartic acid proteases that cleave the leader peptides of precursor proteins with type iv prepilin signal sequences. the substrate repertoire of pibd from the crenarchaeon sulfolobus solfataricus is unusually diverse. in addition to flagellin, pibd cleaves three sugar-binding proteins unique to this species and a number of proteins with unknown function. here we demonstrate that pibd contains two as ... | 2006 | 16452426 |
| [introduction of transpozon tn9 to endogenic plasmids of erwinia carotovora during lysogenization of cells by coliphage p1]. | it has been shown that phage p1 of escherichia coli is able not only to lysogenize the cells of erwinia carotovora but also to be a source of transpozon tn9 for mutagenesis of cryptic plasmids of this important phytopathogen. since the amount of the introduction in one of plasmids pca25::tn9 is 3.8 kb, at an average, it is supposed that tn9 is inherited as a double tandem structure. a convenient method is offered for selecting bacterial clones carrying the plasmid pca25::tn9 which is based on co ... | 2006 | 17100326 |
| detection and characterization of bacteria from the potato rhizosphere degrading n-acyl-homoserine lactone. | quorum sensing plays a role in the regulation of soft rot diseases caused by the plant pathogenic bacterium pectobacterium carotovorum subsp. carotovorum. the signal molecules involved in quorum sensing in p. carotovorum subsp. carotovorum belong to the group of n-acyl homoserine lactones (ahls). in our study, we screened bacteria isolated from the potato rhizosphere for the ability to degrade ahls produced by p. carotovorum subsp. carotovorum. six isolates able to degrade ahls were selected for ... | 2006 | 17110970 |
| substrate recognition by the hetero-octameric atp phosphoribosyltransferase from lactococcus lactis. | two families of atp phosphoribosyl transferases (atp-prt) join atp and 5-phosphoribosyl-1 pyrophosphate (prpp) in the first reaction of histidine biosynthesis. these consist of a homohexameric form found in all three kingdoms and a hetero-octameric form largely restricted to bacteria. hetero-octameric atp-prts consist of four hisgs catalytic subunits related to periplasmic binding proteins and four hisz regulatory subunits that resemble histidyl-trna synthetases. to clarify the relationship betw ... | 2006 | 17154531 |