| the missing link: bordetella petrii is endowed with both the metabolic versatility of environmental bacteria and virulence traits of pathogenic bordetellae. | bordetella petrii is the only environmental species hitherto found among the otherwise host-restricted and pathogenic members of the genus bordetella. phylogenetically, it connects the pathogenic bordetellae and environmental bacteria of the genera achromobacter and alcaligenes, which are opportunistic pathogens. b. petrii strains have been isolated from very different environmental niches, including river sediment, polluted soil, marine sponges and a grass root. recently, clinical isolates asso ... | 2008 | 18826580 |
| regulatory and structural properties differentiating the chromosomal and the bacteriophage-associated escherichia coli o157:h7 cu, zn superoxide dismutases. | highly virulent enterohemorrhagic escherichia coli o157:h7 strains possess three sodc genes encoding for periplasmic cu, zn superoxide dismutases: sodc, which is identical to the gene present in non-pathogenic e. coli strains, and sodc-f1 and sodc-f2, two nearly identical genes located within lambdoid prophage sequences. the significance of this apparent sodc redundancy in e. coli o157:h7 has not yet been investigated. | 2008 | 18828904 |
| the role of aiia, a quorum-quenching enzyme from bacillus thuringiensis, on the rhizosphere competence. | bacteria sense their population density and coordinate the expression of target genes, including virulence factors in gram-negative bacteria, by the n-acylhomoserine lactones (ahls)-dependent quorum-sensing (qs) mechanism. in contrast, several soil bacteria are able to interfere with qs by enzymatic degradation of ahls, referred to as quorum quenching. a potent ahl-degrading enzyme, aiia, of bacillus thuringiensis has been reported to effectively attenuate the virulence of bacteria by quorum que ... | 2008 | 18852506 |
| rare codons cluster. | most amino acids are encoded by more than one codon. these synonymous codons are not used with equal frequency: in every organism, some codons are used more commonly, while others are more rare. though the encoded protein sequence is identical, selective pressures favor more common codons for enhanced translation speed and fidelity. however, rare codons persist, presumably due to neutral drift. here, we determine whether other, unknown factors, beyond neutral drift, affect the selection and/or d ... | 2008 | 18923675 |
| the pmra/pmrb two-component system of legionella pneumophila is a global regulator required for intracellular replication within macrophages and protozoa. | to examine the role of the pmra/pmrb two-component system (tcs) of legionella pneumophila in global gene regulation and in intracellular infection, we constructed pmra and pmrb isogenic mutants by allelic exchange. genome-wide microarray gene expression analyses of the pmra and pmrb mutants at both the exponential and the postexponential phases have shown that the pmra/pmrb tcs has a global effect on the expression of 279 genes classified into nine groups of genes encoding eukaryotic-like protei ... | 2009 | 18936184 |
| the pmra/pmrb two-component system of legionella pneumophila is a global regulator required for intracellular replication within macrophages and protozoa. | to examine the role of the pmra/pmrb two-component system (tcs) of legionella pneumophila in global gene regulation and in intracellular infection, we constructed pmra and pmrb isogenic mutants by allelic exchange. genome-wide microarray gene expression analyses of the pmra and pmrb mutants at both the exponential and the postexponential phases have shown that the pmra/pmrb tcs has a global effect on the expression of 279 genes classified into nine groups of genes encoding eukaryotic-like protei ... | 2009 | 18936184 |
| ethylene-insensitive tobacco shows differentially altered susceptibility to different pathogens. | abstract transgenic tobacco plants (tetr) expressing the mutant etr1-1 gene from arabidopsis thaliana are insensitive to ethylene and develop symptoms of wilting and stem rot when grown in nonautoclaved soil. several isolates of fusarium, thielaviopsis, and pythium were recovered from stems of diseased tetr plants. inoculation with each of these isolates of 6-week-old plants growing in autoclaved soil caused disease in tetr plants but not in nontransformed plants. also, when 2-week-old seedlings ... | 2003 | 18943162 |
| 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 |
| an oligonucleotide array for the identification and differentiation of bacteria pathogenic on potato. | abstract oligonucleotides, 16 to 24 bases long, were selected from the 3' end of the 16s gene and the 16s-23s intergenic spacer regions of bacteria pathogenic on potato, including clavibacter michiganensis subsp. sepedonicus, ralstonia solanacearum, and the pectolytic erwinias, including erwinia carotovora subsp. atroseptica and carotovora and e. chrysanthemi. oligonucleotides were designed and formatted into an array by pin spotting on nylon membranes. genomic dna from bacterial cultures was am ... | 2003 | 18944335 |
| interdisciplinary bacteria and phages. | a report of the meeting 'molecular genetics of bacteria and phages', cold spring harbor, usa, 20-24 august 2008. | 2008 | 18947378 |
| quorum sensing primes the oxidative stress response in the insect endosymbiont, sodalis glossinidius. | sodalis glossinidius, a maternally transmitted bacterial endosymbiont of tsetse flies (glossina spp.), uses an acylated homoserine lactone (ahl)-based quorum sensing system to modulate gene expression in accordance with bacterial cell density. the s. glossinidius quorum sensing system relies on the function of two regulatory proteins; sogi (a luxi homolog) synthesizes a signaling molecule, characterized as n-(3-oxohexanoyl) homoserine lactone (ohhl), and sogr1 (a luxr homolog) interacts with ohh ... | 2008 | 18958153 |
| gonococcal cervicitis: a role for biofilm in pathogenesis. | neisseria gonorrhoeae forms a biofilm in flow cells on glass coverslips as well as on primary cervical epithelial cells. electron microscopic studies of cervical biopsy specimens from 10 patients with culture-proven n. gonorrhoeae infection revealed evidence of biofilm formation in 3 of the biopsy specimens. these biofilms showed gonococci in networks of bacterial membrane within the biofilm structure. this finding was also observed in biofilms formed over glass cover slips and after infection o ... | 2008 | 18973432 |
| evf, a virulence factor produced by the drosophila pathogen erwinia carotovora, is an s-palmitoylated protein with a new fold that binds to lipid vesicles. | erwinia carotovora are phytopathogenic gram-negative bacteria of agronomic interest as these bacteria are responsible for fruit soft rot and use insects as dissemination vectors. the erwinia carotovora carotovora strain 15 (ecc15) is capable of persisting in the drosophila gut by the sole action of one protein, erwinia virulence factor (evf). however, the precise function of evf is elusive, and its sequence does not provide any indication as to its biochemical function. we have solved the 2.0-an ... | 2009 | 18978353 |
| early responses of tobacco suspension cells to rhizobacterial elicitors of induced systemic resistance. | colonization of roots by selected strains of fluorescent pseudomonas spp. can trigger induced systemic resistance (isr) against foliar pathogens in a plant species-specific manner. it has been suggested that early responses in cell suspension cultures in response to rhizobacterial elicitors, such as generation of active oxygen species (aos) and extracellular medium alkalinization (ma), are linked to the development of isr in whole plants. perception of flagellin was demonstrated to elicit isr in ... | 2008 | 18986257 |
| galactinol is a signaling component of the induced systemic resistance caused by pseudomonas chlororaphis o6 root colonization. | root colonization by pseudomonas chlororaphis o6 in cucumber elicited an induced systemic resistance (isr) against corynespora cassiicola. in order to gain insight into o6-mediated isr, a suppressive subtractive hybridization technique was applied and resulted in the isolation of a cucumber galactinol synthase (csgols1) gene. the transcriptional level of csgols1 and the resultant galactinol content showed an increase several hours earlier under o6 treatment than in the water control plants follo ... | 2008 | 18986260 |
| sinorhizobium meliloti, a bacterium lacking the autoinducer-2 (ai-2) synthase, responds to ai-2 supplied by other bacteria. | many bacterial species respond to the quorum-sensing signal autoinducer-2 (ai-2) by regulating different niche-specific genes. here, we show that sinorhizobium meliloti, a plant symbiont lacking the gene for the ai-2 synthase, while not capable of producing ai-2 can nonetheless respond to ai-2 produced by other species. we demonstrate that s. meliloti has a periplasmic binding protein that binds ai-2. the crystal structure of this protein (here named smlsrb) with its ligand reveals that it binds ... | 2008 | 18990189 |
| two dissimilar n-acyl-homoserine lactone acylases of pseudomonas syringae influence colony and biofilm morphology. | plant aerial surfaces comprise a complex habitat for microorganisms, and many plant-associated bacteria, such as the pathogen pseudomonas syringae, exhibit density-dependent survival on leaves by utilizing quorum sensing (qs). qs is often mediated by diffusible signals called n-acyl-homoserine lactones (ahls), and p. syringae utilizes n-3-oxo-hexanoyl-dl-homoserine lactone (3oc6hsl) to control traits influencing epiphytic fitness and virulence. the p. syringae pathovar syringae b728a genome sequ ... | 2009 | 18997027 |
| two dissimilar n-acyl-homoserine lactone acylases of pseudomonas syringae influence colony and biofilm morphology. | plant aerial surfaces comprise a complex habitat for microorganisms, and many plant-associated bacteria, such as the pathogen pseudomonas syringae, exhibit density-dependent survival on leaves by utilizing quorum sensing (qs). qs is often mediated by diffusible signals called n-acyl-homoserine lactones (ahls), and p. syringae utilizes n-3-oxo-hexanoyl-dl-homoserine lactone (3oc6hsl) to control traits influencing epiphytic fitness and virulence. the p. syringae pathovar syringae b728a genome sequ ... | 2009 | 18997027 |
| characterization of the myo-inositol utilization island of salmonella enterica serovar typhimurium. | knockout mutation of stm4432 resulted in a growth-deficient phenotype of salmonella enterica serovar typhimurium in the presence of myo-inositol (mi) as the sole carbon source. stm4432 is part of a 22.6-kb genomic island which spans stm4417 to stm4436 (genomic island 4417/4436) and is responsible for mi degradation. genome comparison revealed the presence of this island in only six salmonella strains and a high variability of the iol gene organization in gram-negative bacteria. upon nonpolar del ... | 2009 | 19011032 |
| characterization of the myo-inositol utilization island of salmonella enterica serovar typhimurium. | knockout mutation of stm4432 resulted in a growth-deficient phenotype of salmonella enterica serovar typhimurium in the presence of myo-inositol (mi) as the sole carbon source. stm4432 is part of a 22.6-kb genomic island which spans stm4417 to stm4436 (genomic island 4417/4436) and is responsible for mi degradation. genome comparison revealed the presence of this island in only six salmonella strains and a high variability of the iol gene organization in gram-negative bacteria. upon nonpolar del ... | 2009 | 19011032 |
| srnamap: genomic maps for small non-coding rnas, their regulators and their targets in microbial genomes. | small non-coding rnas (srnas) carry out a variety of biological functions and affect protein synthesis and protein activities in prokaryotes. recently, numerous srnas and their targets were identified in escherichia coli and in other bacteria. it is crucial to have a comprehensive resource concerning the annotation of small non-coding rnas in microbial genomes. this work presents an integrated database, namely srnamap, to collect the srna genes, the transcriptional regulators of srnas and the sr ... | 2009 | 19015153 |
| srnamap: genomic maps for small non-coding rnas, their regulators and their targets in microbial genomes. | small non-coding rnas (srnas) carry out a variety of biological functions and affect protein synthesis and protein activities in prokaryotes. recently, numerous srnas and their targets were identified in escherichia coli and in other bacteria. it is crucial to have a comprehensive resource concerning the annotation of small non-coding rnas in microbial genomes. this work presents an integrated database, namely srnamap, to collect the srna genes, the transcriptional regulators of srnas and the sr ... | 2009 | 19015153 |
| bactericidal and fungicidal activities of calia secundiflora (ort.) yakovlev. | calia secundiflora (ortega) yakovlev (fabaceae) is considered a medicinal plant in mexico but has scarcely been used because of the toxicity of its quinolizidine alkaloids. several quinolizidine alkaloids have shown bactericidal, nematicidal, and fungicidal activities. the purpose of this study was to identify the alkaloids in the seeds and evaluate the activity of the organic extract on several phytopathogenic fungi and bacteria. an in vitro bioassay was conducted with species of the following ... | 2008 | 19040102 |
| acquisition and evolution of plant pathogenesis-associated gene clusters and candidate determinants of tissue-specificity in xanthomonas. | xanthomonas is a large genus of plant-associated and plant-pathogenic bacteria. collectively, members cause diseases on over 392 plant species. individually, they exhibit marked host- and tissue-specificity. the determinants of this specificity are unknown. | 2008 | 19043590 |
| purification, crystallization and preliminary x-ray diffraction analysis of an oomycete-derived nep1-like protein. | the elicitor protein nep1-like protein from the plant pathogen pythium aphanidermatum was purified and crystallized using the hanging-drop vapour-diffusion method. a native data set was collected to 1.35 a resolution at 100 k using synchrotron radiation. since selenomethionine-labelled protein did not crystallize under the original conditions, a second crystal form was identified that yielded crystals that diffracted to 2.1 a resolution. a multiple-wavelength anomalous dispersion (mad) experimen ... | 2008 | 19052381 |
| cloning and characterization of uronate dehydrogenases from two pseudomonads and agrobacterium tumefaciens strain c58. | uronate dehydrogenase has been cloned from pseudomonas syringae pv. tomato strain dc3000, pseudomonas putida kt2440, and agrobacterium tumefaciens strain c58. the genes were identified by using a novel complementation assay employing an escherichia coli mutant incapable of consuming glucuronate as the sole carbon source but capable of growth on glucarate. a shotgun library of p. syringae was screened in the mutant e. coli by growing transformed cells on minimal medium containing glucuronic acid. ... | 2009 | 19060141 |
| cloning and characterization of uronate dehydrogenases from two pseudomonads and agrobacterium tumefaciens strain c58. | uronate dehydrogenase has been cloned from pseudomonas syringae pv. tomato strain dc3000, pseudomonas putida kt2440, and agrobacterium tumefaciens strain c58. the genes were identified by using a novel complementation assay employing an escherichia coli mutant incapable of consuming glucuronate as the sole carbon source but capable of growth on glucarate. a shotgun library of p. syringae was screened in the mutant e. coli by growing transformed cells on minimal medium containing glucuronic acid. ... | 2009 | 19060141 |
| purine utilization by klebsiella oxytoca m5al: genes for ring-oxidizing and -opening enzymes. | the enterobacterium klebsiella oxytoca uses a variety of inorganic and organic nitrogen sources, including purines, nitrogen-rich compounds that are widespread in the biosphere. we have identified a 23-gene cluster that encodes the enzymes for utilizing purines as the sole nitrogen source. growth and complementation tests with insertion mutants, combined with sequence comparisons, reveal functions for the products of these genes. here, we report our characterization of 12 genes, one encoding gua ... | 2009 | 19060149 |
| purine utilization by klebsiella oxytoca m5al: genes for ring-oxidizing and -opening enzymes. | the enterobacterium klebsiella oxytoca uses a variety of inorganic and organic nitrogen sources, including purines, nitrogen-rich compounds that are widespread in the biosphere. we have identified a 23-gene cluster that encodes the enzymes for utilizing purines as the sole nitrogen source. growth and complementation tests with insertion mutants, combined with sequence comparisons, reveal functions for the products of these genes. here, we report our characterization of 12 genes, one encoding gua ... | 2009 | 19060149 |
| toxin-antitoxin systems in escherichia coli influence biofilm formation through yjgk (taba) and fimbriae. | the roles of toxin-antitoxin (ta) systems in bacteria have been debated. here, the role of five ta systems in regard to biofilm development was investigated (listed as toxin/antitoxin: mazf/maze, rele/relb, chpb, yoeb/yefm, and yafq/dinj). although these multiple ta systems were reported previously to not impact bacterial fitness, we found that deletion of the five ta systems decreased biofilm formation initially (8 h) on three different surfaces and then increased biofilm formation (24 h) by de ... | 2009 | 19060153 |
| toxin-antitoxin systems in escherichia coli influence biofilm formation through yjgk (taba) and fimbriae. | the roles of toxin-antitoxin (ta) systems in bacteria have been debated. here, the role of five ta systems in regard to biofilm development was investigated (listed as toxin/antitoxin: mazf/maze, rele/relb, chpb, yoeb/yefm, and yafq/dinj). although these multiple ta systems were reported previously to not impact bacterial fitness, we found that deletion of the five ta systems decreased biofilm formation initially (8 h) on three different surfaces and then increased biofilm formation (24 h) by de ... | 2009 | 19060153 |
| [identification and characterization of novel antimicrobial protein apn5 against erwinia carotovora]. | amorphophallus soft rot disease, caused by erwinia carotovora, affects amorphophallus industry development. we identified and characterized protein apn5 against erwinia carotovora, isolated from bacillus subtilis strain bsn5. | 2008 | 19062643 |
| quorum quenching in agrobacterium tumefaciens: chance or necessity? | | 2009 | 19074377 |
| quorum quenching in agrobacterium tumefaciens: chance or necessity? | | 2009 | 19074377 |
| the r1162 mob proteins can promote conjugative transfer from cryptic origins in the bacterial chromosome. | the mobilization proteins of the broad-host-range plasmid r1162 can initiate conjugative transfer of a plasmid from a 19-bp locus that is partially degenerate in sequence. such loci are likely to appear by chance in the bacterial chromosome and could act as cryptic sites for transfer of chromosomal dna when r1162 is present. the r1162-dependent transfer of chromosomal dna, initiated from one such potential site in pectobacterium atrosepticum, is shown here. a second active site was identified in ... | 2009 | 19074386 |
| the r1162 mob proteins can promote conjugative transfer from cryptic origins in the bacterial chromosome. | the mobilization proteins of the broad-host-range plasmid r1162 can initiate conjugative transfer of a plasmid from a 19-bp locus that is partially degenerate in sequence. such loci are likely to appear by chance in the bacterial chromosome and could act as cryptic sites for transfer of chromosomal dna when r1162 is present. the r1162-dependent transfer of chromosomal dna, initiated from one such potential site in pectobacterium atrosepticum, is shown here. a second active site was identified in ... | 2009 | 19074386 |
| gdsl lipase-like 1 regulates systemic resistance associated with ethylene signaling in arabidopsis. | systemic resistance is induced by necrotizing pathogenic microbes and non-pathogenic rhizobacteria and confers protection against a broad range of pathogens. here we show that arabidopsis gdsl lipase-like 1 (glip1) plays an important role in plant immunity, eliciting both local and systemic resistance in plants. glip1 functions independently of salicylic acid but requires ethylene signaling. enhancement of glip1 expression in plants increases resistance to pathogens including alternaria brassici ... | 2009 | 19077166 |
| an orphan luxr homolog of sinorhizobium meliloti affects stress adaptation and competition for nodulation. | the sin/expr quorum-sensing system of sinorhizobium meliloti plays an important role in the symbiotic association with its host plant, medicago sativa. the luxr-type response regulators of the sin system include the synthase (sini)-associated sinr and the orphan regulator expr. interestingly, the s. meliloti rm1021 genome codes for four additional putative orphan luxr homologs whose regulatory roles remain to be identified. these response regulators contain the characteristic domains of the luxr ... | 2009 | 19088317 |
| an orphan luxr homolog of sinorhizobium meliloti affects stress adaptation and competition for nodulation. | the sin/expr quorum-sensing system of sinorhizobium meliloti plays an important role in the symbiotic association with its host plant, medicago sativa. the luxr-type response regulators of the sin system include the synthase (sini)-associated sinr and the orphan regulator expr. interestingly, the s. meliloti rm1021 genome codes for four additional putative orphan luxr homologs whose regulatory roles remain to be identified. these response regulators contain the characteristic domains of the luxr ... | 2009 | 19088317 |
| isolation of the bacteriophage dinohi from dichelobacter nodosus and its interactions with other integrated genetic elements. | the gram-negative anaerobic pathogen dichelobacter nodosus carries several genetic elements that integrate into the chromosome. these include the inta, intb, intc and intd elements, which integrate adjacent to csra and pnpa, two putative global regulators of virulence and the virulence-related locus, vrl, which integrates into ssra. treatment of d. nodosus strains with ultraviolet light resulted in the isolation of dinohi, a member of the siphoviridae and the first bacteriophage to be identified ... | 2008 | 19088904 |
| assessment of genetic and functional diversity of phosphate solubilizing fluorescent pseudomonads isolated from rhizospheric soil. | phosphorus is an essential macronutrient for the growth of plants. however, in most soils a large portion of phosphorus becomes insoluble and therefore, unavailable to plants. knowledge on biodiversity of phosphate-solubilizing fluorescent pseudomonads is essential to understand their ecological role and their utilization in sustainable agriculture. | 2008 | 19099598 |
| profilegrids as a new visual representation of large multiple sequence alignments: a case study of the reca protein family. | multiple sequence alignments are a fundamental tool for the comparative analysis of proteins and nucleic acids. however, large data sets are no longer manageable for visualization and investigation using the traditional stacked sequence alignment representation. | 2008 | 19102758 |
| conditional essentiality of the csra gene in escherichia coli. | csra is a global posttranscriptional regulator of numerous physiological processes, such as glycogenesis and glycolysis. here, we show that the csra gene of escherichia coli is essential for growth on lb and on synthetic medium containing glycolytic carbon sources. however, csra is not necessary for growth on synthetic medium containing pyruvate, showing that the krebs cycle is functional in the csra::cat deletion mutant. deletion of the glgcap operon in the csra::cat mutant restored the ability ... | 2009 | 19103924 |
| conditional essentiality of the csra gene in escherichia coli. | csra is a global posttranscriptional regulator of numerous physiological processes, such as glycogenesis and glycolysis. here, we show that the csra gene of escherichia coli is essential for growth on lb and on synthetic medium containing glycolytic carbon sources. however, csra is not necessary for growth on synthetic medium containing pyruvate, showing that the krebs cycle is functional in the csra::cat deletion mutant. deletion of the glgcap operon in the csra::cat mutant restored the ability ... | 2009 | 19103924 |
| physicochemical basis for the inhibitory effects of organic and inorganic salts on the growth of pectobacterium carotovorum subsp. carotovorum and pectobacterium atrosepticum. | twenty-one salts were tested for their effects on the growth of pectobacterium carotovorum subsp. carotovorum and pectobacterium atrosepticum. in liquid medium, 11 salts (0.2 m) exhibited strong inhibition of bacterial growth. the inhibitory action of salts relates to the water-ionizing capacity and the lipophilicity of their constituent ions. | 2009 | 19114504 |
| molecular cloning and characterization of a novel pyrethroid-hydrolyzing esterase originating from the metagenome. | abstract: | 2008 | 19116015 |
| the phage abortive infection system, toxin, functions as a protein-rna toxin-antitoxin pair. | various mechanisms exist that enable bacteria to resist bacteriophage infection. resistance strategies include the abortive infection (abi) systems, which promote cell death and limit phage replication within a bacterial population. a highly effective 2-gene abi system from the phytopathogen erwinia carotovora subspecies atroseptica, designated toxin, is described. the toxin abi system also functions as a toxin-antitoxin (ta) pair, with toxn inhibiting bacterial growth and the tandemly repeated ... | 2009 | 19124776 |
| the escherichia coli cell division protein and model tat substrate sufi (ftsp) localizes to the septal ring and has a multicopper oxidase-like structure. | the escherichia coli protein sufi (ftsp) has recently been proposed to be a component of the cell division apparatus. the sufi protein is also in widespread experimental use as a model substrate in studies of the tat (twin arginine translocation) protein transport system. we have used sufi-gfp (green fluorescent protein) fusions to show that sufi localizes to the septal ring in the dividing cell. we have also determined the structure of sufi by x-ray crystallography to a resolution of 1.9 a. suf ... | 2009 | 19135451 |
| the rcs two-component system regulates expression of lysozyme inhibitors and is induced by exposure to lysozyme. | the escherichia coli rcs regulon is triggered by antibiotic-mediated peptidoglycan stress and encodes two lysozyme inhibitors, ivy and mlic. we report activation of this pathway by lysozyme and increased lysozyme sensitivity when rcs induction is genetically blocked. this lysozyme sensitivity could be alleviated by complementation with ivy and mlic. | 2009 | 19136591 |
| arabidopsis gdsl lipase 2 plays a role in pathogen defense via negative regulation of auxin signaling. | glip1 was isolated previously from arabidopsis, as a salicylic acid-responsive secreted gdsl lipase that functions in resistance to alternaria brassicicola [i.s. oh, a.r. park, m.s. bae, s.j. kwon, y.s. kim, j.e. lee, n.y. kang, s. lee, h. cheong, o.k. park, secretome analysis reveals an arabidopsis lipase involved in defense against alternaria brassicicola. plant cell 17 (2005) 2832-2847.]. to extend our knowledge of the roles played by glips in arabidopsis, we conducted functional studies of a ... | 2009 | 19146828 |
| evidence for niche adaptation in the genome of the bovine pathogen streptococcus uberis. | streptococcus uberis, a gram positive bacterial pathogen responsible for a significant proportion of bovine mastitis in commercial dairy herds, colonises multiple body sites of the cow including the gut, genital tract and mammary gland. comparative analysis of the complete genome sequence of s. uberis strain 0140j was undertaken to help elucidate the biology of this effective bovine pathogen. | 2009 | 19175920 |
| diverse antibacterial activity of pectobacterium carotovorum subsp.carotovorum isolated in korea. | fifty-four pectobacterium carotovorum subsp. carotovorum strains isolated in korea were characterized by a spectrum of antibacterial activities against 7 indicator strains chosen to represent various regions and host plants. all p. carotovorum subsp. carotovorum isolates tested could be grouped into 4 classes depending on the pattern of antibacterial substance production. all tested strains had dna fragment(s) homologous to the genes encoding carotovoricin and 21 of them had genes homologous to ... | 2009 | 19190407 |
| rickettsia phylogenomics: unwinding the intricacies of obligate intracellular life. | completed genome sequences are rapidly increasing for rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and rocky mountain spotted fever. in light of phylogeny, the establishment of orthologous groups (ogs) of open reading frames (orfs) will distinguish the core rickettsial genes and other group specific genes (class 1 ogs or c1ogs) from those distributed indiscriminately throughout the rickettsial tree (class 2 og or c2ogs) ... | 2008 | 19194535 |
| identification of an rsh gene from a novosphingobium sp. necessary for quorum-sensing signal accumulation. | the stringent response is a mechanism by which bacteria adapt to environmental stresses and nutritional deficiencies through the synthesis and hydrolysis of (p)ppgpp by rela/spot enzymes. alphaproteobacteria and plants contain a single rsh enzyme (named for rela/spot homolog) that is bifunctional. here we report the identification of a new species of bacteria belonging to the genus novosphingobium and characterization of an rsh mutation in this plant tumor-associated isolate. isolate rr 2-17, fr ... | 2009 | 19201802 |
| antiviral immunity in drosophila requires systemic rna interference spread. | multicellular organisms evolved sophisticated defence systems to confer protection against pathogens. an important characteristic of these immune systems is their ability to act both locally at the site of infection and at distal uninfected locations. in insects, such as drosophila melanogaster, rna interference (rnai) mediates antiviral immunity. however, the antiviral rnai defence in flies seems to be a local, cell-autonomous process, as flies are thought to be unable to generate a systemic rn ... | 2009 | 19204732 |
| lactic acid bacteria from fresh fruit and vegetables as biocontrol agents of phytopathogenic bacteria and fungi. | this study evaluated the efficacy of lactic acid bacteria (lab) isolated from fresh fruits and vegetables as biocontrol agents against the phytopathogenic and spoilage bacteria and fungi, xanthomonas campestris, erwinia carotovora, penicillium expansum, monilinia laxa, and botrytis cinerea. the antagonistic activity of 496 lab strains was tested in vitro and all tested microorganisms except p. expansum were inhibited by at least one isolate. the 496 isolates were also analyzed for the inhibition ... | 2008 | 19204894 |
| antimicrobial activity of some macrophytes from lake manzalah (egypt). | the antimicrobial activities of aqueous and organic solvents (chloroform, ethanol and methanol) extracts of four plants ceratophyllum demersum l., eichhornia crassipes, potamogeton crispus and potamogeton pectinatus were tested in vitro against seventeen different microorganisms including gram-positive and gram-negative bacteria and fungi. nine of these identified organisms were obtained from different sources, bacillus subtilis 1020, bacillus cereus 1080, staphylococcus aureus, erwinia carotovo ... | 2008 | 19205264 |
| [antitumor activity of l-asparaginase from yersinia pseudotuberculosis]. | the cytotoxic activity of l-asparaginases from yersinia pseudotuberculosis and from erwinia carotovora were investigated in vitro using several tumor cells lines: jurkat and molt-4 (human t-lymphoblastic leukemia), mcf-7 (human breast adenocarcinoma), lncap (human prostate carcinoma), nguk1 (rat gasser node neurinoma). e. coli l-asparaginase produced by "medak" (germany) was used as a reference. the cell growth inhibition data indicate that y. pseudotuberculosis l-asparaginase significantly inhi ... | 2008 | 19205431 |
| control of foodborne pathogens and soft-rot bacteria on bell pepper by three strains of bacterial antagonists. | forty-two representative strains of native bacteria associated with fresh peeled baby carrots were isolated and characterized. two of these strains, identified as pseudomonas fluorescens ag3a (pf ag3a) and bacillus yd1, were evaluated in conjunction with another known antagonist, p. fluorescens 2-79 (pf 2-79), for their potential as biocontrol agents of human pathogens (listeria monocytogenes, yersinia enterocolitica, salmonella enterica, and escherichia coli o157:h7) and soft-rot bacteria (erwi ... | 2009 | 19205468 |
| crystal structure of the n-terminal domain of the secretin gspd from etec determined with the assistance of a nanobody. | secretins are among the largest bacterial outer membrane proteins known. here we report the crystal structure of the periplasmic n-terminal domain of gspd (peri-gspd) from the type 2 secretion system (t2ss) secretin in complex with a nanobody, the vhh domain of a heavy-chain camelid antibody. two different crystal forms contained the same compact peri-gspd:nanobody heterotetramer. the nanobody contacts peri-gspd mainly via cdr3 and framework residues. the peri-gspd structure reveals three subdom ... | 2009 | 19217396 |
| drosophila intestinal response to bacterial infection: activation of host defense and stem cell proliferation. | although drosophila systemic immunity is extensively studied, little is known about the fly's intestine-specific responses to bacterial infection. global gene expression analysis of drosophila intestinal tissue to oral infection with the gram-negative bacterium erwinia carotovora revealed that immune responses in the gut are regulated by the imd and jak-stat pathways, but not the toll pathway. ingestion of bacteria had a dramatic impact on the physiology of the gut that included modulation of st ... | 2009 | 19218090 |
| regulation of igaa and the rcs system by the mvia response regulator in salmonella enterica. | igaa is a membrane protein that prevents overactivation of the rcs regulatory system in enteric bacteria. here we provide evidence that igaa is the first gene in a sigma(70)-dependent operon of salmonella enterica serovar typhimurium that also includes yrfg, yrfh, and yrfi. we also show that the lon protease and the mvia response regulator participate in regulation of the igaa operon. our results indicate that mvia regulates igaa transcription in an rpos-dependent manner, but the results also su ... | 2009 | 19218385 |
| characterization of regulatory pathways in xylella fastidiosa: genes and phenotypes controlled by gaca. | the xylem-limited, insect-transmitted bacterium xylella fastidiosa causes pierce's disease in grapes through cell aggregation and vascular clogging. gaca controls various physiological processes and pathogenicity factors in many gram-negative bacteria, including biofilm formation in pseudomonas syringae pv. tomato dc3000. cloned gaca of x. fastidiosa was found to restore the hypersensitive response and pathogenicity in gaca mutants of p. syringae pv. tomato dc3000 and erwinia amylovora. a gaca m ... | 2009 | 19218414 |
| engineering thermal stability of l-asparaginase by in vitro directed evolution. | l-asparaginase (ec 3.5.1.1, l-asnase) catalyses the hydrolysis of l-asn, producing l-asp and ammonia. this enzyme is an anti-neoplastic agent; it is used extensively in the chemotherapy of acute lymphoblastic leukaemia. in this study, we describe the use of in vitro directed evolution to create a new enzyme variant with improved thermal stability. a library of enzyme variants was created by a staggered extension process using the genes that code for the l-asnases from erwinia chrysanthemi and er ... | 2009 | 19220855 |
| short-term starvation of immune deficient drosophila improves survival to gram-negative bacterial infections. | primary immunodeficiencies are inborn errors of immunity that lead to life threatening conditions. these predispositions describe human immunity in natura and highlight the important function of components of the toll-il-1- receptor-nuclear factor kappa b (tir-nf-kappab) pathway. since the tir-nf-kappab circuit is a conserved component of the host defence in higher animals, genetically tractable models may contribute ideas for clinical interventions. | 2009 | 19221590 |
| glycogen contributes to the environmental persistence and transmission of vibrio cholerae. | pathogenic vibrio cholerae cycle between the nutrient-rich human intestinal tract and nutrient-poor aquatic environments and currently few bacterial factors are known that aid in the transition between these disparate environments. we hypothesized that the ability to store carbon as glycogen would facilitate both bacterial fitness in the aquatic environment and transmission of v. cholerae to new hosts. to investigate the role of glycogen in v. cholerae transmission, we constructed mutants that c ... | 2009 | 19226328 |
| metagenomics revealed a quorum quenching lactonase qlca from yet unculturable soil bacteria. | quorum sensing (qs) is a signal mediated cell-cell communication system that couples bacterial cell density to a synchronized gene expression (fuqua et al., 1994). mostly, in gram negative bacteria qs signals are n-acylhomoserine lactones (nahls) that coordinate important functions such as virulence and pathogenicity. qs signals or the elements involved in their production or perception could be targeted to disrupt qs, a phenomenon called quorum quenching (qq). qq properties (chemicals and enzym ... | 2008 | 19226736 |
| crystal structure of yfeu protein from haemophilus influenzae: a predicted etherase involved in peptidoglycan recycling. | the crystal structure of the h. influenzae yfeu protein, was determined at 1.90 a resolution using multi-wavelength anomalous diffraction. yfeu belongs to a very large conserved family of proteins found mainly in bacteria but also in archaea and eukaryota. the protein is a homolog of eukaryotic glucokinase regulator and is predicted to be a sugar phosphate isomerase or aminotransferase. here we describe the structure of yfeu and discuss the possible function as an etherase possibly involved in p ... | 2009 | 19234762 |
| infection induces a survival program and local remodeling in the airway epithelium of the fly. | although the prevalence of inflammatory airway diseases is steadily growing, our knowledge regarding the underlying molecular and cellular mechanisms is fragmentary. the striking simplicity of the fruit fly's airway epithelium, which is composed of epithelial cells only, justifies its use as a model to study general features and response characteristics of airway epithelia in general. infection with the gram-negative pathogen erwinia carotovora induces an immune response in all epithelial cells ... | 2009 | 19237508 |
| a novel plasmid for detection of n-acyl homoserine lactones. | many bacteria utilize acyl-homoserine lactones as cell to cell signals that can regulate the expression of numerous genes. structural differences in acyl-homoserine lactones produced by different bacteria, such as acyl side chain length and the presence or absence of an oxy group, make many of the commonly used detection bioassays impractical for broad range detection. here we present a simple, broad range acyl-homoserine lactone detection bioassay that can be used to detect a wide range of thes ... | 2009 | 19248807 |
| fate of the h-ns-repressed bgl operon in evolution of escherichia coli. | in the enterobacterial species escherichia coli and salmonella enterica, expression of horizontally acquired genes with a higher than average at content is repressed by the nucleoid-associated protein h-ns. a classical example of an h-ns-repressed locus is the bgl (aryl-beta,d-glucoside) operon of e. coli. this locus is "cryptic," as no laboratory growth conditions are known to relieve repression of bgl by h-ns in e. coli k12. however, repression can be relieved by spontaneous mutations. here, w ... | 2009 | 19266030 |
| genetic mapping of secretion and functional determinants of the vibrio cholerae tcpf colonization factor. | colonization of the human small intestine by vibrio cholerae requires the type iv toxin-coregulated pilus (tcp). tcpf, which is encoded within the tcp operon, is secreted from the bacterial cell by the tcp apparatus and is also essential for colonization. bacteria lacking tcpf are deficient in colonization, and anti-tcpf antibodies are protective in the infant mouse cholera model. in order to elucidate the regions of the protein that are required for secretion through the tcp apparatus and for i ... | 2009 | 19304855 |
| structure and heme binding properties of escherichia coli o157:h7 chux. | for many pathogenic microorganisms, iron acquisition from host heme sources stimulates growth, multiplication, ultimately enabling successful survival and colonization. in gram-negative escherichia coli o157:h7, shigella dysenteriae and yersinia enterocolitica the genes encoded within the heme utilization operon enable the effective uptake and utilization of heme as an iron source. while the complement of proteins responsible for heme internalization has been determined in these organisms, the f ... | 2009 | 19319934 |
| the three-dimensional structure of the cytoplasmic domains of epsf from the type 2 secretion system of vibrio cholerae. | the type 2 secretion system (t2ss), a multi-protein machinery that spans both the inner and the outer membranes of gram-negative bacteria, is used for the secretion of several critically important proteins across the outer membrane. here we report the crystal structure of the n-terminal cytoplasmic domain of epsf, an inner membrane spanning t2ss protein from vibrio cholerae. this domain consists of a bundle of six anti-parallel helices and adopts a fold that has not been described before. the lo ... | 2009 | 19324092 |
| genome-wide functional divergence after the symbiosis of proteobacteria with insects unraveled through a novel computational approach. | symbiosis has been among the most important evolutionary steps to generate biological complexity. the establishment of symbiosis required an intimate metabolic link between biological systems with different complexity levels. the strict endo-cellular symbiotic bacteria of insects are beautiful examples of the metabolic coupling between organisms belonging to different kingdoms, a eukaryote and a prokaryote. the host (eukaryote) provides the endosymbiont (prokaryote) with a stable cellular enviro ... | 2009 | 19343224 |
| development of medium for enhanced production of glutaminase-free l-asparaginase from pectobacterium carotovorum mtcc 1428. | glutaminase-free l-asparaginase is known to be an excellent anticancer agent. in the present study, statistically based experimental designs were applied to maximize the production of glutaminase-free l-asparaginase from pectobacterium carotovorum mtcc 1428. nine components of the medium were examined for their significance on the production of l-asparaginase using the plackett-burman experimental design. the medium components, viz., glucose, l-asparagine, kh2po4, and mgso(4).7h2o, were screened ... | 2009 | 19352649 |
| identification and characterization of hemolysin-like proteins similar to rtx toxin in pasteurella pneumotropica. | pasteurella pneumotropica is an opportunistic pathogen that causes lethal pneumonia in immunodeficient rodents. the virulence factors of this bacterium remain unknown. in this study, we identified the genes encoding two rtx toxins, designated as pnxi and pnxii, from the genomic dna of p. pneumotropica atcc 35149 and characterized with respect to hemolysis. the pnxi operon was organized according to the manner in which the genes encoded the structural rtx toxin (pnxia), the type i secretion syste ... | 2009 | 19363112 |
| a conserved tyrosyl-glutamyl catalytic dyad in evolutionarily linked enzymes: carbapenam synthetase and beta-lactam synthetase. | beta-lactam-synthesizing enzymes carbapenam synthetase (cps) and beta-lactam synthetase (beta-ls) are evolutionarily linked to a common ancestor, asparagine synthetase b (as-b). these three relatives catalyze substrate acyl-adenylation and nucleophilic acyl substitution by either an external (as-b) or internal (cps, beta-ls) nitrogen source. unlike as-b, crystal structures of cps and beta-ls revealed a putative tyr-glu dyad (cps, y345/e380; beta-ls, y348/e382) proposed to deprotonate the respect ... | 2009 | 19371088 |
| characterization of two homologous disulfide bond systems involved in virulence factor biogenesis in uropathogenic escherichia coli cft073. | disulfide bond (dsb) formation is catalyzed by disulfide bond proteins and is critical for the proper folding and functioning of secreted and membrane-associated bacterial proteins. uropathogenic escherichia coli (upec) strains possess two paralogous disulfide bond systems: the well-characterized dsbab system and the recently described dsbli system. in the dsbab system, the highly oxidizing dsba protein introduces disulfide bonds into unfolded polypeptides by donating its redox-active disulfide ... | 2009 | 19376849 |
| a metabolic operon in extraintestinal pathogenic escherichia coli promotes fitness under stressful conditions and invasion of eukaryotic cells. | we identified a carbohydrate metabolic operon (frz) that is highly associated with extraintestinal pathogenic escherichia coli (expec) strains. the frz operon codes for three subunits of a phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) transporter of the fructose subfamily, for a transcriptional activator of ptss of the mga family, for two type ii ketose-1,6-bisphosphate aldolases, for a sugar-specific kinase (repressor, open reading frame, kinase family [rok]), and for a prote ... | 2009 | 19376853 |
| quorum-sensing control of antibiotic synthesis in burkholderia thailandensis. | the genome of burkholderia thailandensis codes for several luxr-luxi quorum-sensing systems. we used b. thailandensis quorum-sensing deletion mutants and recombinant escherichia coli to determine the nature of the signals produced by one of the systems, btar2-btai2, and to show that this system controls genes required for the synthesis of an antibiotic. btai2 is an acyl-homoserine lactone (acyl-hsl) synthase that produces two hydroxylated acyl-hsls, n-3-hydroxy-decanoyl-hsl (3ohc(10)-hsl) and n- ... | 2009 | 19376863 |
| pectin methylesterase napme1 contributes to the emission of methanol during insect herbivory and to the elicitation of defence responses in nicotiana attenuata. | pectin methylesterases (pmes) catalyse the demethylation of pectin within plant cell walls, releasing methanol (meoh) in the process. thus far, pmes have been found to be involved in diverse processes such as plant growth and development and defence responses against pathogens. herbivore attack increases pme expression and activity and meoh emissions in several plant species. to gain further insights into the role of pmes in defence responses against herbivores, the expression of a manduca sexta ... | 2009 | 19380422 |
| improving protein extraction and separation methods for investigating the metaproteome of anaerobic benzene communities within sediments. | btex compounds such as benzene are frequent soil and groundwater contaminants that are easily biodegraded under oxic conditions by bacteria. in contrast, benzene is rather recalcitrant under anaerobic conditions. the analysis of anoxic degradation is often hampered by difficult sampling conditions, limited amounts of biomass and interference of matrix compounds with proteomic approaches. in order to improve the procedure for protein extraction we established a scheme consisting of the following ... | 2009 | 19381451 |
| comparative metagenomics of daphnia symbionts. | shotgun sequences of dna extracts from whole organisms allow a comprehensive assessment of possible symbionts. the current project makes use of four shotgun datasets from three species of the planktonic freshwater crustaceans daphnia: one dataset from clones of d. pulex and d. pulicaria and two datasets from one clone of d. magna. we analyzed these datasets with three aims: first, we search for bacterial symbionts, which are present in all three species. second, we search for evidence for cyanob ... | 2009 | 19383155 |
| two small ncrnas jointly govern virulence and transmission in legionella pneumophila. | to transit from intra- to extracellular environments, legionella pneumophila differentiates from a replicative/non-virulent to a transmissive/virulent form using the two-component system leta/lets and the global repressor protein csra. while investigating how both regulators act co-ordinately we characterized two ncrnas, rsmy and rsmz, that link the leta/lets and csra regulatory networks. we demonstrate that leta directly regulates their expression and show that rsmy and rsmz are functional in e ... | 2009 | 19400772 |
| specific genomic sequences of e. coli promote replicational initiation by directly reactivating adp-dnaa. | in escherichia coli, atp-dnaa, unlike adp-dnaa, can initiate chromosomal replication at oric. the level of cellular atp-dnaa fluctuates, peaking at around the time of replication initiation. however, it remains unknown how the atp-dnaa level increases coordinately with the replication cycle. in this study, we show that two chromosomal intergenic regions, herein termed dnaa-reactivating sequence 1 (dars1) and dnaa-reactivating sequence 2 (dars2), directly promote regeneration of atp-dnaa from adp ... | 2009 | 19401329 |
| phylogeny and virulence of naturally occurring type iii secretion system-deficient pectobacterium strains. | pectobacterium species are enterobacterial plant-pathogenic bacteria that cause soft rot disease in diverse plant species. previous epidemiological studies of pectobacterium species have suffered from an inability to identify most isolates to the species or subspecies level. we used three previously described dna-based methods, 16s-23s intergenic transcribed spacer pcr-restriction fragment length polymorphism analysis, multilocus sequence analysis (mlsa), and pulsed-field gel electrophoresis, to ... | 2009 | 19411432 |
| arabidopsis harmless to ozone layer protein methylates a glucosinolate breakdown product and functions in resistance to pseudomonas syringae pv. maculicola. | almost all of the chlorine-containing gas emitted from natural sources is methyl chloride (ch(3)cl), which contributes to the destruction of the stratospheric ozone layer. tropical and subtropical plants emit substantial amounts of ch(3)cl. a gene involved in ch(3)cl emission from arabidopsis was previously identified and designated harmless to ozone layer (hereafter athol1) based on the mutant phenotype. our previous studies demonstrated that athol1 and its homologs, athol2 and athol3, have s-a ... | 2009 | 19419967 |
| a probable aculeacin a acylase from the ralstonia solanacearum gmi1000 is n-acyl-homoserine lactone acylase with quorum-quenching activity. | the infection and virulence functions of diverse plant and animal pathogens that possess quorum sensing systems are regulated by n-acylhomoserine lactones (ahls) acting as signal molecules. ahl-acylase is a quorum quenching enzyme and degrades ahls by removing the fatty acid side chain from the homoserine lactone ring of ahls. this blocks ahl accumulation and pathogenic phenotypes in quorum sensing bacteria. | 2009 | 19426552 |
| multiple activities of the plant pathogen type iii effector proteins wtse and avre require wxxxe motifs. | the broadly conserved avre-family of type iii effectors from gram-negative plant-pathogenic bacteria includes important virulence factors, yet little is known about the mechanisms by which these effectors function inside plant cells to promote disease. we have identified two conserved motifs in avre-family effectors: a wxxxe motif and a putative c-terminal endoplasmic reticulum membrane retention/retrieval signal (ermrs). the wxxxe and ermrs motifs are both required for the virulence activities ... | 2009 | 19445595 |
| small rna identification in enterobacteriaceae using synteny and genomic backbone retention ii. | small rnas are bacterial counterparts of noncoding rnas. increasing evidence being added in the literature indicates that these small rnas play major roles in prokaryotes both at the transcriptome and proteome levels. based on comparative genomic studies, we present manually curated small rna regions in 25 recently completed genomes from enterobacteriaceae. the study is a continuation of our earlier work that uses the presence of small rnas sandwiched between specific conserved flanking genes re ... | 2009 | 19445646 |
| rsmc of erwinia carotovora subsp. carotovora negatively controls motility, extracellular protein production, and virulence by binding flhd and modulating transcriptional activity of the master regulator, flhdc. | rsmc and flhdc are global regulators controlling extracellular proteins/enzymes, rsmb rna, motility, and virulence of erwinia carotovora subsp. carotovora. flhdc, the master regulator of flagellar genes, controls these traits by positively regulating gaca, flia, and rsmc and negatively regulating hexa. rsmc, on the other hand, is a negative regulator of extracellular proteins/enzymes, motility, and virulence since the deficiency of rsmc in flhdc(+) strain results in overproduction of extracellul ... | 2009 | 19447906 |
| pathogenic stimulation of intestinal stem cell response in drosophila. | stem cell-mediated tissue repair is a promising approach for many diseases. mammalian intestine is an actively regenerating tissue such that epithelial cells are constantly shedding and underlying precursor cells are constantly replenishing the loss of cells. an imbalance of these processes will lead to intestinal diseases including inflammation and cancer. mammalian intestinal stem cells (iscs) are located in bases of crypts but at least two groups of cells have been cited as stem cells. moreov ... | 2009 | 19452446 |
| systems level analysis of two-component signal transduction systems in erwinia amylovora: role in virulence, regulation of amylovoran biosynthesis and swarming motility. | two-component signal transduction systems (tcsts), consisting of a histidine kinase (hk) and a response regulator (rr), represent a major paradigm for signal transduction in prokaryotes. tcsts play critical roles in sensing and responding to environmental conditions, and in bacterial pathogenesis. most tcsts in erwinia amylovora have either not been identified or have not yet been studied. | 2009 | 19470164 |
| isolation and characterization of endophytic and rhizosphere bacterial antagonists of soft rot pathogen from pinellia ternata. | pinellia ternata, a traditional chinese herb that has been used in china for over 1000 years, is susceptible to a soft rot disease, which may cause major loss of yield. the use of bacteria as potential antagonists against pectobacterium carotovorum sxr1, the causal agent of the disease on p. ternata, was evaluated. altogether, 1107 candidate bacteria were isolated from the rhizosphere and surface-sterilized plants of p. ternata. in petri dish tests, 55 isolates inhibited the growth of strain sxr ... | 2009 | 19473246 |
| the phobr two-component system regulates antibiotic biosynthesis in serratia in response to phosphate. | secondary metabolism in serratia sp. atcc 39006 (serratia 39006) is controlled via a complex network of regulators, including a luxir-type (smair) quorum sensing (qs) system. here we investigate the molecular mechanism by which phosphate limitation controls biosynthesis of two antibiotic secondary metabolites, prodigiosin and carbapenem, in serratia 39006. | 2009 | 19476633 |
| structural basis for the erythro-stereospecificity of the l-arginine oxygenase vioc in viomycin biosynthesis. | the nonheme iron oxygenase vioc from streptomyces vinaceus catalyzes fe(ii)-dependent and alpha-ketoglutarate-dependent cbeta-hydroxylation of l-arginine during the biosynthesis of the tuberactinomycin antibiotic viomycin. crystal structures of vioc were determined in complexes with the cofactor fe(ii), the substrate l-arginine, the product (2s,3s)-hydroxyarginine and the coproduct succinate at 1.1-1.3 a resolution. the overall structure reveals a beta-helix core fold with two additional helical ... | 2009 | 19490124 |
| identification and expression analysis of wrky transcription factor genes in canola (brassica napus l.) in response to fungal pathogens and hormone treatments. | members of plant wrky transcription factor families are widely implicated in defense responses and various other physiological processes. for canola (brassica napus l.), no wrky genes have been described in detail. because of the economic importance of this crop, and its evolutionary relationship to arabidopsis thaliana, we sought to characterize a subset of canola wrky genes in the context of pathogen and hormone responses. | 2009 | 19493335 |
| genome-wide transcriptomic profiling of anopheles gambiae hemocytes reveals pathogen-specific signatures upon bacterial challenge and plasmodium berghei infection. | the mosquito anopheles gambiae is a major vector of human malaria. increasing evidence indicates that blood cells (hemocytes) comprise an essential arm of the mosquito innate immune response against both bacteria and malaria parasites. to further characterize the role of hemocytes in mosquito immunity, we undertook the first genome-wide transcriptomic analyses of adult female an. gambiae hemocytes following infection by two species of bacteria and a malaria parasite. | 2009 | 19500340 |
| identification of an isr-related metabolite produced by rhizobacterium klebsiella oxytoca c1036 active against soft-rot disease pathogen in tobacco. | klebsiella oxytoca c1036 (c1036) causes induced systemic resistance (isr) activity against the soft-rot pathogen pectobacterium carotovorum subsp. carotovorum scc1 (scc1). however, microbial metabolites from c1036 involved in isr activity remain unknown. the present study was performed to identify an isr-related metabolite produced by c1036. | 2009 | 19504536 |