Publications

protein splicing of sufb is crucial for the functionality of the mycobacterium tuberculosis suf machinery.	the sufbcd complex is an essential component of the suf machinery of [fe-s] cluster biogenesis in many organisms. we show here that in mycobacterium tuberculosis the formation of this complex is dependent on the protein splicing of sufb, suggesting that this process is a potential new target for antituberculous drugs.	2006	16621837
transcriptional analysis of the bglp gene from streptococcus mutans.	an open reading frame encoding a putative antiterminator protein, lict, was identified in the genomic sequence of streptococcus mutans. a potential ribonucleic antitermination (rat) site to which the lict protein would potentially bind has been identified immediately adjacent to this open reading frame. the lict gene and rat site are both located 5' to a beta-glucoside pts regulon previously described in s. mutans that is responsible for esculin utilization in the presence of glucose. it was hyp ...	2006	16630357
the effect of polysaccharide-degrading wine yeast transformants on the efficiency of wine processing and wine flavour.	commercial polysaccharase preparations are applied to winemaking to improve wine processing and quality. expression of polysaccharase-encoding genes in saccharomyces cerevisiae allows for the recombinant strains to degrade polysaccharides that traditional commercial yeast strains cannot. in this study, we constructed recombinant wine yeast strains that were able to degrade the problem-causing grape polysaccharides, glucan and xylan, by separately integrating the trichoderma reesei xyn2 xylanase ...	2006	16644051
factors that influence the activity of 2,4-dihydroxy-7-methoxy-2h-1,4-benzoxazin-3(4h)-one on erwinia species in growth assays.	factors affecting the inhibitory activity of 2,4-dihydroxy-7-methoxy-2h-1,4-benzoxazin-3(4h)-one (dimboa) against erwinia carotovora, a nonpathogen of zea mays l., and against a maize pathovar of erwinia chrysanthemi (ecz) were examined. most experiments were performed with dimboa dissolved in a bacterial growth medium containing 10 g/liter of sucrose, inorganic salts, and 1 g/liter of casamino acids at ph 6.75. when temperature and ph were held constant, inhibition of e. carotovora varied linea ...	1978	16660389
transient activation of plasmalemma k efflux and h influx in tobacco by a pectate lyase isozyme from erwinia chrysanthemi.	a purified pectate lyase isozyme derived from erwinia chrysanthemi induced rapid net k(+) efflux and h(+) influx in suspension-cultured tobacco cells. comparable fluxes of other ions (na(+), cl(-)) were not observed. the k(+) efflux/h(+) influx response began within 15 minutes after addition of enzyme to cell suspensions and continued for approximately 1 hour after which cells resumed the net h(+) efflux exhibited prior to enzyme treatment. the response was not prolonged by a second enzyme dose ...	1986	16664981
isolation and characterization of acid-tolerant, thermophilic bacteria for effective fermentation of biomass-derived sugars to lactic acid.	biomass-derived sugars, such as glucose, xylose, and other minor sugars, can be readily fermented to fuel ethanol and commodity chemicals by the appropriate microbes. due to the differences in the optimum conditions for the activity of the fungal cellulases that are required for depolymerization of cellulose to fermentable sugars and the growth and fermentation characteristics of the current industrial microbes, simultaneous saccharification and fermentation (ssf) of cellulose is envisioned at c ...	2006	16672461
characterization of the siderophore of francisella tularensis and role of fsla in siderophore production.	we determined that lvs and schu s4 strains of the human pathogen francisella tularensis express a siderophore when grown under iron-limiting conditions. we purified this siderophore by conventional column chromatography and high-pressure liquid chromatography and used mass spectrometric analysis to demonstrate that it is structurally similar to the polycarboxylate siderophore rhizoferrin. the siderophore promoted the growth of lvs and schu s4 strains in iron-limiting media. we identified a poten ...	2006	16707671
the synchrony phenotype persists after elimination of multiple gatc sites from the dnaa promoter of escherichia coli.	to examine whether methylation of the gatc sites present in the dnaa promoter region is responsible for the strict temporal coordination of initiation events at oric as measured by the synchrony of initiation, we introduced point mutations eliminating three (tgw1) and five (tgw2) of the six gatc sites present in the dnaa promoter region. all of the strains containing these mutations, including the one with five gatc sites eliminated, initiated chromosomal replication synchronously.	2006	16740964
the role of several multidrug resistance systems in erwinia chrysanthemi pathogenesis.	the role of several multidrug resistance (mdr) systems in the pathogenicity of erwinia chrysanthemi 3937 was analyzed. using the blast algorithm, we have identified several mdr systems in the e. chrysanthemi genome and selected two acridine resistance (acr)-like systems, two emr-like systems, and one member of the major facilitator super-family family to characterize. we generated mutants in genes encoding for these systems and analyzed the virulence of the mutant strains in different hosts and ...	2006	16776294
the brucella abortus cyclic beta-1,2-glucan virulence factor is substituted with o-ester-linked succinyl residues.	brucella periplasmic cyclic beta-1,2-glucan plays an important role during bacterium-host interaction. nuclear magnetic resonance spectrometry analysis, thin-layer chromatography, and deae-sephadex chromatography were used to characterize brucella abortus cyclic glucan. in the present study, we report that a fraction of b. abortus cyclic beta-1,2-glucan is substituted with succinyl residues, which confer anionic character on the cyclic beta-1,2-glucan. the oligosaccharide backbone is substituted ...	2006	16816173
molecular characterization of pantoea stewartii subsp. stewartii hrpy, a conserved response regulator of the hrp type iii secretion system, and its interaction with the hrps promoter.	pantoea stewartii subsp. stewartii is a bacterial pathogen of corn. its pathogenicity depends on the translocation of effector proteins into host cells by the hrp type iii secretion system. we previously showed by genetic analysis that the hrpx sensor kinase and the hrpy response regulator are at the head of a complex cascade of regulators controlling hrp/hrc secretion and wts effector genes. this cascade also includes the hrps response regulator and the hrpl alternative sigma factor. these regu ...	2006	16816181
direct evidence for the modulation of the activity of the erwinia chrysanthemi quorum-sensing regulator expr by acylhomoserine lactone pheromone.	in erwinia chrysanthemi production of pectic enzymes is controlled by a complex network involving several regulators. among them is expr, the quorum-sensing regulatory protein. expr is a member of the luxr family of transcriptional regulators, the activity of which is modulated by the binding of diffusible n-acylhomoserine lactone pheromones to the n-terminal receptor site of the proteins. previous in vitro dna-expr binding studies suggested that expr might activate pectic enzyme production and ...	2006	16831870
identification and characterization of an azotobacter vinelandii type i secretion system responsible for export of the alge-type mannuronan c-5-epimerases.	alginate is a linear copolymer of beta-d-mannuronic acid and its c-5-epimer, alpha-l-guluronic acid. during biosynthesis, the polymer is first made as mannuronan, and various fractions of the monomers are then epimerized to guluronic acid by mannuronan c-5-epimerases. the azotobacter vinelandii genome encodes a family of seven extracellular such epimerases (alge1 to alge7) which display motifs characteristic for proteins secreted via a type i pathway. putative atpase-binding cassette regions fro ...	2006	16855245
proline betaine uptake in sinorhizobium meliloti: characterization of prb, an opp-like abc transporter regulated by both proline betaine and salinity stress.	sinorhizobium meliloti uses proline betaine (pb) as an osmoprotectant when osmotically stressed and as an energy source in low-osmolarity environments. to fulfill this dual function, two separate pb transporters, bets and hut, that contribute to pb uptake at high and low osmolarity, respectively, have been previously identified. here, we characterized a novel transport system that mediates the uptake of pb at both high and low osmolarities. sequence analysis of tn5-luxab chromosomal insertions f ...	2006	16923898
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
the single transmembrane segment drives self-assembly of outc and the formation of a functional type ii secretion system in erwinia chrysanthemi.	many pathogenic gram-negative bacteria secrete toxins and lytic enzymes via a multiprotein complex called the type ii secretion system. this system, named out in erwinia chrysanthemi, consists of 14 proteins integrated or associated with the two bacterial membranes. outc, a key player in this process, is probably implicated in the recognition of secreted proteins and signal transduction. outc possesses a short cytoplasmic sequence, a single transmembrane segment (tms), and a large periplasmic re ...	2006	16956883
elucidation of the hrp clusters of xanthomonas oryzae pv. oryzicola that control the hypersensitive response in nonhost tobacco and pathogenicity in susceptible host rice.	xanthomonas oryzae pv. oryzicola, the cause of bacterial leaf streak in rice, possesses clusters of hrp genes that determine its ability to elicit a hypersensitive response (hr) in nonhost tobacco and pathogenicity in host rice. a 27-kb region of the genome of x. oryzae pv. oryzicola (rs105) was identified and sequenced, revealing 10 hrp, 9 hrc (hrp conserved), and 8 hpa (hrp-associated) genes and 7 regulatory plant-inducible promoter boxes. while the region from hpa2 to hpab and the hrpf operon ...	2006	16957248
l-asparaginase from erwinia chrysanthemi 3937: cloning, expression and characterization.	bacterial l-asparaginases (l-asnases) catalyze the conversion of l-asparagine to l-aspartate and ammonia. in the present work, we report the cloning and expression of l-asparaginase from erwinia chrysanthemi 3937 (erl-asnase) in escherichia coli bl21(de3)plyss. the enzyme was purified to homogeneity in a single-step procedure involving cation exchange chromatography on an s-sepharose ff column. the enzymatic and structural properties of the recombinant enzyme were investigated and the kinetic pa ...	2007	16984804
disruption of n-acyl homoserine lactone-mediated cell signaling and iron acquisition in epiphytic bacteria by leaf surface compounds.	since n-acyl homoserine lactones (ahls) are key mediators of cell density-dependent regulation of traits involved in virulence and epiphytic fitness in gram-negative bacteria such as pseudomonas syringae, a variety of plant species were examined to determine their production of leaf surface compounds that could interact with these signaling systems. leaf washings of 17 of 52 plant species tested stimulated or inhibited ahl-dependent traits in at least one of the bacterial reporter strains used. ...	2006	16997987
modeling the onset of virulence in a pectinolytic bacterium.	building up from experimental knowledge of the regulatory network of the pel genes in the bacteria e. chrysanthemi, we propose for the first time a qualitative modeling of the infectious transition of this bacteria when it is hosted in a plant. we show that this infectious transition can be understood as the excitable dynamics of a metabolico-genetic network. our mathematical model can account for the main phases which are observed in the onset of the pathogenecity by erwinia chrysanthemi, namel ...	2007	17005207
pleiotropic role of quorum-sensing autoinducer 2 in photorhabdus luminescens.	bacterial virulence is an integrative process that may involve quorum sensing. in this work, we compared by global expression profiling the wild-type entomopathogenic photorhabdus luminescens subsp. laumondii tt01 to a luxs-deficient mutant unable to synthesize the type 2 quorum-sensing inducer ai-2. ai-2 was shown to regulate more than 300 targets involved in most compartments and metabolic pathways of the cell. ai-2 is located high in the hierarchy, as it controls the expression of several tra ...	2006	17021191
wtse, an avre-family effector protein from pantoea stewartii subsp. stewartii, causes disease-associated cell death in corn and requires a chaperone protein for stability.	the pathogenicity of pantoea stewartii subsp. stewartii to sweet corn and maize requires a hrp type iii secretion system. in this study, we genetically and functionally characterized a disease-specific (dsp) effector locus, composed of wtse and wtsf, that is adjacent to the hrp gene cluster. wtse, a member of the avre family of effector proteins, was essential for pathogenesis on corn and was complemented by dspa/e from erwinia amylovora. an intact c-terminus of wtse, which contained a putative ...	2006	17022173
characterization of xync from bacillus subtilis subsp. subtilis strain 168 and analysis of its role in depolymerization of glucuronoxylan.	secretion of xylanase activities by bacillus subtilis 168 supports the development of this well-defined genetic system for conversion of methylglucuronoxylan (megaxn [where n represents the number of xylose residues]) in the hemicellulose component of lignocellulosics to biobased products. in addition to the characterized glycosyl hydrolase family 11 (gh 11) endoxylanase designated xyna, b. subtilis 168 secretes a second endoxylanase as the translated product of the ynff gene. this sequence show ...	2006	17028274
[molecular identification and genetic diversity in konnyaku's soft rot bacteria].	the soft rot bacteria erwinia are an important pathogens of konnyaku and other ornamental plants. thirty-three strains were isolated from soft-rotted konnyaku and other ornamental plants. according to the characteristics of pathogenicity and culture character on semi selective medium (crystal violet pectate, cvp), most of strains tested caused rotten symptom in tubers and stems of konnyaku, and characteristic deep cavities were formed on cvp. to amplify 16s-23s rdna intergenic transcribed spacer ...	2006	17037047
integration of curated databases to identify genotype-phenotype associations.	the ability to rapidly characterize an unknown microorganism is critical in both responding to infectious disease and biodefense. to do this, we need some way of anticipating an organism's phenotype based on the molecules encoded by its genome. however, the link between molecular composition (i.e. genotype) and phenotype for microbes is not obvious. while there have been several studies that address this challenge, none have yet proposed a large-scale method integrating curated biological inform ...	2006	17038185
high levels of expression of the iron-sulfur proteins phthalate dioxygenase and phthalate dioxygenase reductase in escherichia coli.	phthalate dioxygenase (pdo), a hexamer with one rieske-type [2fe-2s] and one fe (ii)-mononuclear center per monomer, and its reductase (pdr), which contains flavin mononucleotide and a plant-type ferredoxin [2fe-2s] center, are expressed by burkholderia cepacia at approximately 30mg of crude pdo and approximately 1mg of crude pdr per liter of cell culture when grown with phthalate as the main carbon source. a high level expression system in escherichia coli was developed for pdo and pdr. optimiz ...	2007	17049880
high levels of expression of the iron-sulfur proteins phthalate dioxygenase and phthalate dioxygenase reductase in escherichia coli.	phthalate dioxygenase (pdo), a hexamer with one rieske-type [2fe-2s] and one fe (ii)-mononuclear center per monomer, and its reductase (pdr), which contains flavin mononucleotide and a plant-type ferredoxin [2fe-2s] center, are expressed by burkholderia cepacia at approximately 30mg of crude pdo and approximately 1mg of crude pdr per liter of cell culture when grown with phthalate as the main carbon source. a high level expression system in escherichia coli was developed for pdo and pdr. optimiz ...	2007	17049880
nps6, encoding a nonribosomal peptide synthetase involved in siderophore-mediated iron metabolism, is a conserved virulence determinant of plant pathogenic ascomycetes.	nps6, encoding a nonribosomal peptide synthetase, is a virulence determinant in the maize (zea mays) pathogen cochliobolus heterostrophus and is involved in tolerance to h(2)o(2). deletion of nps6 orthologs in the rice (oryza sativa) pathogen, cochliobolus miyabeanus, the wheat (triticum aestivum) pathogen, fusarium graminearum, and the arabidopsis thaliana pathogen, alternaria brassicicola, resulted in reduced virulence and hypersensitivity to h(2)o(2). introduction of the nps6 ortholog from th ...	2006	17056706
bacterial outer membrane secretin puld assembles and inserts into the inner membrane in the absence of its pilotin.	dodecamerization and insertion of the outer membrane secretin puld is entirely determined by the c-terminal half of the polypeptide (puld-cs). in the absence of its cognate chaperone puls, puld-cs and puld mislocalize to the inner membrane, from which they are extractable with detergents but not urea. electron microscopy of puld-cs purified from the inner membrane revealed apparently normal dodecameric complexes. electron microscopy of puld-cs and puld in inner membrane vesicles revealed inserte ...	2006	17082772
the symbiosis regulator rscs controls the syp gene locus, biofilm formation and symbiotic aggregation by vibrio fischeri.	successful colonization of a eukaryotic host by a microbe involves complex microbe-microbe and microbe-host interactions. previously, we identified in vibrio fischeri a putative sensor kinase, rscs, required for initiating symbiotic colonization of its squid host euprymna scolopes. here, we analysed the role of rscs by isolating an allele, rscs1, with increased activity. multicopy rscs1 activated transcription of genes within the recently identified symbiosis polysaccharide (syp) cluster. wild-t ...	2006	17087775
the tolc homologue of brucella suis is involved in resistance to antimicrobial compounds and virulence.	brucella spp., like other pathogens, must cope with the environment of diverse host niches during the infection process. in doing this, pathogens evolved different type of transport systems to help them survive and disseminate within the host. members of the tolc family have been shown to be involved in the export of chemically diverse molecules ranging from large protein toxins to small toxic compounds. the role of proteins from the tolc family in brucella and other alpha-2-proteobacteria has b ...	2007	17088356
the tolc homologue of brucella suis is involved in resistance to antimicrobial compounds and virulence.	brucella spp., like other pathogens, must cope with the environment of diverse host niches during the infection process. in doing this, pathogens evolved different type of transport systems to help them survive and disseminate within the host. members of the tolc family have been shown to be involved in the export of chemically diverse molecules ranging from large protein toxins to small toxic compounds. the role of proteins from the tolc family in brucella and other alpha-2-proteobacteria has b ...	2007	17088356
tdea, a tolc-like protein required for toxin and drug export in aggregatibacter (actinobacillus) actinomycetemcomitans.	aggregatibacter actinomycetemcomitans is an oral bacterium that causes localized aggressive periodontitis (lap) and extra-oral infections such as sub-acute infective endocarditis. as part of its array of virulence factors, a. actinomycetemcomitans produces leukotoxin (ltxa), a member of the rtx family of toxins. ltxa kills human leukocytes and we have recently shown that the toxin is required for beta-hemolysis by a. actinomycetemcomitans on solid medium. in other rtx toxin-producing bacteria, a ...	2007	17116373
tdea, a tolc-like protein required for toxin and drug export in aggregatibacter (actinobacillus) actinomycetemcomitans.	aggregatibacter actinomycetemcomitans is an oral bacterium that causes localized aggressive periodontitis (lap) and extra-oral infections such as sub-acute infective endocarditis. as part of its array of virulence factors, a. actinomycetemcomitans produces leukotoxin (ltxa), a member of the rtx family of toxins. ltxa kills human leukocytes and we have recently shown that the toxin is required for beta-hemolysis by a. actinomycetemcomitans on solid medium. in other rtx toxin-producing bacteria, a ...	2007	17116373
anthrax pathogen evades the mammalian immune system through stealth siderophore production.	systemic anthrax, caused by inhalation or ingestion of bacillus anthracis spores, is characterized by rapid microbial growth stages that require iron. tightly bound and highly regulated in a mammalian host, iron is scarce during an infection. to scavenge iron from its environment, b. anthracis synthesizes by independent pathways two small molecules, the siderophores bacillibactin (bb) and petrobactin (pb). despite the great efficiency of bb at chelating iron, pb may be the only siderophore neces ...	2006	17132740
hpar, a putative marr family transcriptional regulator, is positively controlled by hrpg and hrpx and involved in the pathogenesis, hypersensitive response, and extracellular protease production of xanthomonas campestris pathovar campestris.	the marr family of transcriptional regulators of bacteria are involved in the regulation of many cellular processes, including pathogenesis. in this work, we have demonstrated genetically that hpar (hpa, hrp associated), which encodes a putative marr family regulator, is involved in the hypersensitive response (hr), pathogenicity, and extracellular protease production of the phytopathogenic bacterium xanthomonas campestris pathovar campestris. a mutation in hpar resulted in complete loss of viru ...	2007	17158655
hpar, a putative marr family transcriptional regulator, is positively controlled by hrpg and hrpx and involved in the pathogenesis, hypersensitive response, and extracellular protease production of xanthomonas campestris pathovar campestris.	the marr family of transcriptional regulators of bacteria are involved in the regulation of many cellular processes, including pathogenesis. in this work, we have demonstrated genetically that hpar (hpa, hrp associated), which encodes a putative marr family regulator, is involved in the hypersensitive response (hr), pathogenicity, and extracellular protease production of the phytopathogenic bacterium xanthomonas campestris pathovar campestris. a mutation in hpar resulted in complete loss of viru ...	2007	17158655
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
effects of the magnesium and chloride ions and shikimate on the structure of shikimate kinase from mycobacterium tuberculosis.	bacteria, fungi and plants can convert carbohydrate and phosphoenolpyruvate into chorismate, which is the precursor of various aromatic compounds. the seven enzymes of the shikimate pathway are responsible for this conversion. shikimate kinase (sk) is the fifth enzyme in this pathway and converts shikimate to shikimate-3-phosphate. in this work, the conformational changes that occur on binding of shikimate, magnesium and chloride ions to sk from mycobacterium tuberculosis (mtsk) are described. i ...	2007	17183161
effects of the magnesium and chloride ions and shikimate on the structure of shikimate kinase from mycobacterium tuberculosis.	bacteria, fungi and plants can convert carbohydrate and phosphoenolpyruvate into chorismate, which is the precursor of various aromatic compounds. the seven enzymes of the shikimate pathway are responsible for this conversion. shikimate kinase (sk) is the fifth enzyme in this pathway and converts shikimate to shikimate-3-phosphate. in this work, the conformational changes that occur on binding of shikimate, magnesium and chloride ions to sk from mycobacterium tuberculosis (mtsk) are described. i ...	2007	17183161
glucosylglycerate biosynthesis in the deepest lineage of the bacteria: characterization of the thermophilic proteins gpgs and gpgp from persephonella marina.	the pathway for the synthesis of glucosylglycerate (gg) in the thermophilic bacterium persephonella marina is proposed based on the activities of recombinant glucosyl-3-phosphoglycerate (gpg) synthase (gpgs) and glucosyl-3-phosphoglycerate phosphatase (gpgp). the sequences of gpgs and gpgp from the cold-adapted bacterium methanococcoides burtonii were used to identify the homologues in the genome of p. marina, which were separately cloned and overexpressed as his-tagged proteins in escherichia c ...	2007	17189358
glucosylglycerate biosynthesis in the deepest lineage of the bacteria: characterization of the thermophilic proteins gpgs and gpgp from persephonella marina.	the pathway for the synthesis of glucosylglycerate (gg) in the thermophilic bacterium persephonella marina is proposed based on the activities of recombinant glucosyl-3-phosphoglycerate (gpg) synthase (gpgs) and glucosyl-3-phosphoglycerate phosphatase (gpgp). the sequences of gpgs and gpgp from the cold-adapted bacterium methanococcoides burtonii were used to identify the homologues in the genome of p. marina, which were separately cloned and overexpressed as his-tagged proteins in escherichia c ...	2007	17189358
the fox operon from rhodobacter strain sw2 promotes phototrophic fe(ii) oxidation in rhodobacter capsulatus sb1003.	anoxygenic photosynthesis based on fe(ii) is thought to be one of the most ancient forms of metabolism and is hypothesized to represent a transition step in the evolution of oxygenic photosynthesis. however, little is known about the molecular basis of this process because, until recently (y. jiao and d. k. newman, j. bacteriol. 189:1765-1773, 2007), most phototrophic fe(ii)-oxidizing bacteria have been genetically intractable. in this study, we circumvented this problem by taking a heterologous ...	2007	17189371
the fox operon from rhodobacter strain sw2 promotes phototrophic fe(ii) oxidation in rhodobacter capsulatus sb1003.	anoxygenic photosynthesis based on fe(ii) is thought to be one of the most ancient forms of metabolism and is hypothesized to represent a transition step in the evolution of oxygenic photosynthesis. however, little is known about the molecular basis of this process because, until recently (y. jiao and d. k. newman, j. bacteriol. 189:1765-1773, 2007), most phototrophic fe(ii)-oxidizing bacteria have been genetically intractable. in this study, we circumvented this problem by taking a heterologous ...	2007	17189371
global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of erwinia chrysanthemi 3937.	production of the plant hormone indole-3-acetic acid (iaa) is widespread among plant-associated microorganisms. the non-gall-forming phytopathogen erwinia chrysanthemi 3937 (strain ech3937) possesses iaam (asap16562) and iaah (asap16563) gene homologues. in this work, the null knockout iaam mutant strain ech138 was constructed. the iaa production by ech138 was reduced in m9 minimal medium supplemented with l-tryptophan. compared with wild-type ech3937, ech138 exhibited reduced ability to produce ...	2007	17189441
global effect of indole-3-acetic acid biosynthesis on multiple virulence factors of erwinia chrysanthemi 3937.	production of the plant hormone indole-3-acetic acid (iaa) is widespread among plant-associated microorganisms. the non-gall-forming phytopathogen erwinia chrysanthemi 3937 (strain ech3937) possesses iaam (asap16562) and iaah (asap16563) gene homologues. in this work, the null knockout iaam mutant strain ech138 was constructed. the iaa production by ech138 was reduced in m9 minimal medium supplemented with l-tryptophan. compared with wild-type ech3937, ech138 exhibited reduced ability to produce ...	2007	17189441
genetic analysis of the pela-pele cluster encoding the acidic and basic pectate lyases in erwinia chrysanthemi ec16.	in erwinia chrysanthemi (ec16) the clustered pela and pele genes encode an acidic (pi 4.2) and a basic (pi 10.0) pectate lyase (pel), respectively. the pela gene has been isolated on a 1.2 kb restriction fragment and the direction of transcription determined. dna hybridization analysis showed that the pele sequence shares dna homology with pela but not with pelb or pelc, two genes encoding other pel species in ec16. since pel a and pel e enzymes showed little similarity in terms of catalytic pro ...	1987	17193715
secrets of soil survival revealed by the genome sequence of arthrobacter aurescens tc1.	arthrobacter sp. strains are among the most frequently isolated, indigenous, aerobic bacterial genera found in soils. member of the genus are metabolically and ecologically diverse and have the ability to survive in environmentally harsh conditions for extended periods of time. the genome of arthrobacter aurescens strain tc1, which was originally isolated from soil at an atrazine spill site, is composed of a single 4,597,686 basepair (bp) circular chromosome and two circular plasmids, ptc1 and p ...	2006	17194220
sequence and structural features of carbohydrate binding in proteins and assessment of predictability using a neural network.	protein-carbohydrate interactions are crucial in many biological processes with implications to drug targeting and gene expression. nature of protein-carbohydrate interactions may be studied at individual residue level by analyzing local sequence and structure environments in binding regions in comparison to non-binding regions, which provide an inherent control for such analyses. with an ultimate aim of predicting binding sites from sequence and structure, overall statistics of binding regions ...	2007	17201922
proteomic analysis of the carbonate insoluble outer membrane fraction of the soft-rot pathogen dickeya dadantii (syn. erwinia chrysanthemi) strain 3937.	we present results of the first comprehensive proteomic analysis of the outer membrane of the bacterial phytopathogen dickeya dadantii strain 3937 and its response to virulence-contributing factors such as host plant extract, acidic stress, and iron starvation. we analyzed the carbonate-insoluble membrane fractions, which are highly enriched for outer membrane proteins, using two-dimensional electrophoresis and identified the proteins by maldi-tof ms. forty unique proteins were identified, some ...	2007	17203949
genome sequence and analysis of the soil cellulolytic actinomycete thermobifida fusca yx.	thermobifida fusca is a moderately thermophilic soil bacterium that belongs to actinobacteria. it is a major degrader of plant cell walls and has been used as a model organism for the study of secreted, thermostable cellulases. the complete genome sequence showed that t. fusca has a single circular chromosome of 3,642,249 bp predicted to encode 3,117 proteins and 65 rna species with a coding density of 85%. genome analysis revealed the existence of 29 putative glycoside hydrolases in addition to ...	2007	17209016
ferritins, bacterial virulence and plant defence.	the enterobacterial pathogen erwinia chrysanthemi causes soft rot diseases on a wide range of plants, including the model plant arabidopsis thaliana. this bacterium proliferates in the host by secreting a set of pectin degrading enzymes responsible for symptom development. in addition, survival of this bacterium in planta requires two high-affinity iron acquisition systems mediated by siderophores and protective systems against oxidative damages, suggesting the implication by both partners of ac ...	2007	17216356
a simple enzymatic synthesis of 4-nitrophenyl beta-1,4-d-xylobioside, a chromogenic substrate for assay and differentiation of endoxylanases.	a simple procedure has been elaborated for preparation of 4-nitrophenyl beta-d-xylopyranosyl-1,4-beta-d-xylopyranoside (npx(2)), a chromogenic substrate of some endo-beta-1,4-xylanases. the procedure is based on a self-transfer reaction from 4-nitrophenyl beta-d-xylopyranoside catalyzed by an aureobasidium pullulans and aspergillus niger beta-xylosidases. both enzymes catalyzed only the formation of 4-nitrophenyl glycosides of beta-1,4-xylobiose with a small admixture of 4-nitrophenyl glycoside ...	2007	17223215
the trans-envelope tol-pal complex is part of the cell division machinery and required for proper outer-membrane invagination during cell constriction in e. coli.	fission of bacterial cells involves the co-ordinated invagination of the envelope layers. invagination of the cytoplasmic membrane (im) and peptidoglycan (pg) layer is likely driven by the septal ring organelle. invagination of the outer membrane (om) in gram-negative species is thought to occur passively via its tethering to the underlying pg layer with generally distributed pg-binding om (lipo)proteins. the tol-pal system is energized by proton motive force and is well conserved in gram-negati ...	2007	17233825
species-specific functioning of the pseudomonas xcpq secretin: role for the c-terminal homology domain and lipopolysaccharide.	secretins are oligomeric proteins that mediate the export of macromolecules across the bacterial outer membrane. the members of the secretin superfamily possess a c-terminal homology domain that is important for oligomerization and channel formation, while their n-terminal halves are thought to be involved in system-specific interactions. the xcpq secretin of pseudomonas spp. is a component of the type ii secretion pathway. xcpq from pseudomonas alcaligenes is not able to functionally replace th ...	2007	17277064
drosophila c-type lectins enhance cellular encapsulation.	c-type lectins are calcium-dependent carbohydrate binding proteins, and animal c-type lectins participate in innate immunity and cell-cell interactions. in the fruit fly drosophila melanogaster, more than 30 genes encode c-type lectin domains. however, functions of drosophila c-type lectins in innate immunity are not well understood. this study is to investigate whether two drosophila c-type lectins, cg33532 and cg33533 (designated as dl2 and dl3, respectively), are involved in innate immune res ...	2007	17287021
tailoring structure-function properties of l-asparaginase: engineering resistance to trypsin cleavage.	bacterial l-asnases (l-asparaginases) catalyse the conversion of l-asparagine into l-aspartate and ammonia, and are widely used for the treatment of all (acute lymphoblastic leukaemia). in the present paper, we describe an efficient approach, based on protein chemistry and protein engineering studies, for the construction of trypsin-resistant pegylated l-asnase from erwinia carotovora (ecal-asnase). limited proteolysis of ecal-asnase with trypsin was found to be associated with a first cleavage ...	2007	17313368
proteomic analysis of a non-virulent mutant of the phytopathogenic bacterium erwinia chrysanthemi deficient in osmoregulated periplasmic glucans: change in protein expression is not restricted to the envelope, but affects general metabolism.	osmoregulated periplasmic glucans (opgs) are general constituents of the envelope of gram-negative bacteria. they are required for full virulence of bacterial phytopathogens such as pseudomonas syringae, xanthomonas campestris and erwinia chrysanthemi. e. chrysanthemi is a pectinolytic gamma-proteobacterium that causes soft rot disease on a wide range of plant species. in addition to the loss of virulence, opg mutants exhibit a pleiotropic phenotype that affects motility, bile-salt resistance, e ...	2007	17322196
characterization of a novel two-partner secretion system in escherichia coli o157:h7.	gram-negative bacteria contain multiple secretion pathways that facilitate the translocation of proteins across the outer membrane. the two-partner secretion (tps) system is composed of two essential components, a secreted exoprotein and a pore-forming beta barrel protein that is thought to transport the exoprotein across the outer membrane. a putative tps system was previously described in the annotation of the genome of escherichia coli o157:h7 strain edl933. we found that the two components o ...	2007	17322314
the serine 31 residue of the b subunit of shiga toxin 2 is essential for secretion in enterohemorrhagic escherichia coli.	shiga toxins produced by enterohemorrhagic escherichia coli (ehec) include shiga toxin 1 (stx1) as well as shiga toxin 2 (stx2). stx1 is cell associated, whereas stx2 is localized to the culture supernatant. we have analyzed the secretion of stx2 by generating histidine-tagged stxb (stxb-h). although neither stxb1-h nor stxb2-h was secreted in stxb-h-overexpressed ehec, stxb2-h-overexpressed ehec showed inhibited stx2 secretion. on the other hand, stxb1-h-overexpressed ehec showed no alteration ...	2007	17325057
two host-induced ralstonia solanacearum genes, acra and dinf, encode multidrug efflux pumps and contribute to bacterial wilt virulence.	multidrug efflux pumps (mdrs) are hypothesized to protect pathogenic bacteria from toxic host defense compounds. we created mutations in the ralstonia solanacearum acra and dinf genes, which encode putative mdrs in the broad-host-range plant pathogen. both mutations reduced the ability of r. solanacearum to grow in the presence of various toxic compounds, including antibiotics, phytoalexins, and detergents. both acrab and dinf mutants were significantly less virulent on the tomato plant than the ...	2007	17337552
xpha/xqha, a novel gspcd subunit for type ii secretion in pseudomonas aeruginosa.	the opportunistic human pathogen bacterium pseudomonas aeruginosa secretes various exoproteins in its surrounding environment. protein secretion involves different secretory systems, including the type ii secretion system, or t2ss, that is one of the most efficient secretory pathways of p. aeruginosa. there are two t2ss in this bacterium, the quorum-sensing-regulated xcp system and the hxc system, which is only present under phosphate-limiting conditions. like t2ss of other bacteria, the xcp t2s ...	2007	17351035
quorum sensing, virulence and secondary metabolite production in plant soft-rotting bacteria.	quorum sensing describes the ability of bacteria to sense their population density and respond by modulating gene expression. in the plant soft-rotting bacteria, such as erwinia, an arsenal of plant cell wall-degrading enzymes is produced in a cell density-dependent manner, which causes maceration of plant tissue. however, quorum sensing is central not only to controlling the production of such destructive enzymes, but also to the control of a number of other virulence determinants and secondary ...	2007	17360277
single-step pathway for synthesis of glucosylglycerate in persephonella marina.	a single-step pathway for the synthesis of the compatible solute glucosylglycerate (gg) is proposed based on the activity of a recombinant glucosylglycerate synthase (ggs) from persephonella marina. the corresponding gene encoded a putative glycosyltransferase that was part of an operon-like structure which also contained the genes for glucosyl-3-phosphoglycerate synthase (gpgs) and glucosyl-3-phosphoglycerate phosphatase (gpgp), the enzymes that lead to the synthesis of gg through the formation ...	2007	17369297
efflux pump gene expression in erwinia chrysanthemi is induced by exposure to phenolic acids.	salicylic acid (sa) is an important signaling molecule in local and systemic plant resistance. following infection by microbial pathogens and the initial oxidative burst in plants, sa accumulation functions in the amplification of defense gene expression. production of pathogenesis-related proteins and toxic antimicrobial chemicals serves to protect the plant from infection. successful microbial pathogens utilize a variety of mechanisms to rid themselves of toxic antimicrobial compounds. importa ...	2007	17378434
mode of action of glycoside hydrolase family 5 glucuronoxylan xylanohydrolase from erwinia chrysanthemi.	the mode of action of xylanase a from a phytopathogenic bacterium, erwinia chrysanthemi, classified in glycoside hydrolase family 5, was investigated on xylooligosaccharides and polysaccharides using tlc, maldi-tof ms and enzyme treatment with exoglycosidases. the hydrolytic action of xylanase a was found to be absolutely dependent on the presence of 4-o-methyl-d-glucuronosyl (meglca) side residues in both oligosaccharides and polysaccharides. neutral linear beta-1,4-xylooligosaccharides and est ...	2007	17381510
increased production of xylanase by expression of a truncated version of the xyn11a gene from nonomuraea flexuosa in trichoderma reesei.	we have previously shown that the nonomuraea flexuosa xyn11a polypeptides devoid of the carbohydrate binding module (cbm) have better thermostability than the full-length xylanase and are effective in bleaching of pulp. to produce an enzyme preparation useful for industrial applications requiring high temperature, the region encoding the cbm was deleted from the n. flexuosa xyn11a gene and the truncated gene was expressed in trichoderma reesei. the xylanase sequence was fused to the t. reesei ma ...	2007	17384308
identification of a novel two-partner secretion locus in moraxella catarrhalis.	although moraxella catarrhalis continues to be a significant cause of disease in both children and adults, the steps involved in pathogenesis remain poorly understood. we have identified three open reading frames in the m. catarrhalis genome that encode homologues of the two-partner secretion system (tps). the sequenced m. catarrhalis hemagglutinin-like locus of strain 7169 has a unique gene organization composed in the order of mcha1, mchb, and mcha2, where mcha1 is divergent. mcha1 and mcha2 a ...	2007	17420235
membrane association and multimerization of tcpt, the cognate atpase ortholog of the vibrio cholerae toxin-coregulated-pilus biogenesis apparatus.	the toxin-coregulated pilus (tcp) is one of the major virulence factors of vibrio cholerae. biogenesis of this type 4 pilus (tfp) requires a number of structural components encoded by the tcp operon. tcpt, the cognate putative atpase, is required for tcp biogenesis and all tcp-mediated functions. we studied the stability and localization of tcpt in cells containing in-frame deletions in each of the tcp genes. tcpt was detectable in each of the biogenesis mutants except the deltatcpt strain. tcpt ...	2007	17434972
the iron-responsive element (ire)/iron-regulatory protein 1 (irp1)-cytosolic aconitase iron-regulatory switch does not operate in plants.	animal cytosolic aco (aconitase) and bacteria aco are able to switch to rna-binding proteins [irps (iron-regulatory proteins)], thereby playing a key role in the regulation of iron homoeostasis. in the model plant arabidopsis thaliana, we have identified three irp1 homologues, named aco1-3. to determine whether or not they may encode functional irp proteins and regulate iron homoeostasis in plants, we have isolated loss-of-function mutants in the three genes. the aco1-1 and aco3-1 mutants show a ...	2007	17437406
plant cell wall degradation by saprophytic bacillus subtilis strains: gene clusters responsible for rhamnogalacturonan depolymerization.	plant cell wall degradation is a premier event when bacillus subtilis, a typical saprophytic bacterium, invades plants. here we show the degradation system of rhamnogalacturonan type i (rg-i), a component of pectin from the plant cell wall, in b. subtilis strain 168. strain 168 cells showed a significant growth on plant cell wall polysaccharides such as pectin, polygalacturonan, and rg-i as a carbon source. dna microarray analysis indicated that three gene clusters (yesopqrstuvwxyz, ytepqrst, an ...	2007	17449691
crystal structure and allosteric regulation of the cytoplasmic escherichia coli l-asparaginase i.	ansa is the cytoplasmic asparaginase from escherichia coli involved in intracellular asparagine utilization. analytical ultracentifugation and x-ray crystallography reveal that ansa forms a tetrameric structure as a dimer of two intimate dimers. kinetic analysis of the enzyme reveals that ansa is positively cooperative, displaying a sigmoidal substrate dependence curve with an [s](0.5) of 1 mm l-asparagine and a hill coefficient (n(h)) of 2.6. binding of l-asparagine to an allosteric site was ob ...	2007	17451745
transcriptional profiling of bacillus anthracis during infection of host macrophages.	the interaction between bacillus anthracis and the mammalian phagocyte is one of the central stages in the progression of inhalational anthrax, and it is commonly believed that the host cell plays a key role in facilitating germination and dissemination of inhaled b. anthracis spores. given this, a detailed definition of the survival strategies used by b. anthracis within the phagocyte is critical for our understanding of anthrax. in this study, we report the first genome-wide analysis of b. ant ...	2007	17470545
transport capabilities of eleven gram-positive bacteria: comparative genomic analyses.	the genomes of eleven gram-positive bacteria that are important for human health and the food industry, nine low g+c lactic acid bacteria and two high g+c gram-positive organisms, were analyzed for their complement of genes encoding transport proteins. thirteen to 18% of their genes encode transport proteins, larger percentages than observed for most other bacteria. all of these bacteria possess channel proteins, some of which probably function to relieve osmotic stress. amino acid uptake system ...	2007	17490609
interactions between the lipoprotein pilp and the secretin pilq in neisseria meningitidis.	neisseria meningitidis can be the causative agent of meningitis or septicemia. this bacterium expresses type iv pili, which mediate a variety of functions, including autoagglutination, twitching motility, biofilm formation, adherence, and dna uptake during transformation. the secretin pilq supports type iv pilus extrusion and retraction, but it also requires auxiliary proteins for its assembly and localization in the outer membrane. here we have studied the physical properties of the lipoprotein ...	2007	17526700
human body temperature (37degrees c) increases the expression of iron, carbohydrate, and amino acid utilization genes in escherichia coli k-12.	using dna microarrays, we identified 126 genes in escherichia coli k-12 whose expression is increased at human body temperature (37 degrees c) compared to growth at 23 degrees c. genes involved in the uptake and utilization of amino acids, carbohydrates, and iron dominated the list, supporting a model in which temperature serves as a host cue to increase expression of bacterial genes needed for growth. using quantitative real-time pcr, we investigated the thermoregulatory response for representa ...	2007	17526711
agrobacterium tumefaciens fur has important physiological roles in iron and manganese homeostasis, the oxidative stress response, and full virulence.	in agrobacterium tumefaciens, the balance between acquiring enough iron and avoiding iron-induced toxicity is regulated in part by fur (ferric uptake regulator). a fur mutant was constructed to address the physiological role of the regulator. atypically, the mutant did not show alterations in the levels of siderophore biosynthesis and the expression of iron transport genes. however, the fur mutant was more sensitive than the wild type to an iron chelator, 2,2'-dipyridyl, and was also more resist ...	2007	17545320
restricted cell elongation in arabidopsis hypocotyls is associated with a reduced average pectin esterification level.	cell elongation is mainly limited by the extensibility of the cell wall. dicotyledonous primary (growing) cell walls contain cellulose, xyloglucan, pectin and proteins, but little is known about how each polymer class contributes to the cell wall mechanical properties that control extensibility.	2007	17572910
identification of genes in xanthomonas campestris pv. vesicatoria induced during its interaction with tomato.	xanthomonas campestris pv. vesicatoria is the causal agent of bacterial spot disease of tomato and pepper. the disease process is interactive and very intricate and involves a plethora of genes in the pathogen and in the host. in the pathogen, different genes are activated in response to the changing environment to enable it to survive, adapt, evade host defenses, propagate, and damage the host. to understand the disease process, it is imperative to broaden our understanding of the gene machiner ...	2007	17573477
differential regulation of two oligogalacturonate outer membrane channels, kdgn and kdgm, of dickeya dadantii (erwinia chrysanthemi).	the entry of oligogalacturonates into dickeya dadantii occurs through the specific channel kdgm. the genome of the bacterium encodes a second member of this family of outer membrane proteins, kdgn. we showed that this protein is also involved in the uptake of oligogalacturonates. when kdgn was reconstituted in proteoliposomes, it formed channels with a conductance of about 450 ps at a positive potential. these channels had weak anionic selectivity. the regulation of kdgn is complex, and five gen ...	2007	17573480
resistance to botrytis cinerea in sitiens, an abscisic acid-deficient tomato mutant, involves timely production of hydrogen peroxide and cell wall modifications in the epidermis.	plant defense mechanisms against necrotrophic pathogens, such as botrytis cinerea, are considered to be complex and to differ from those that are effective against biotrophs. in the abscisic acid-deficient sitiens tomato (solanum lycopersicum) mutant, which is highly resistant to b. cinerea, accumulation of hydrogen peroxide (h(2)o(2)) was earlier and stronger than in the susceptible wild type at the site of infection. in sitiens, h(2)o(2) accumulation was observed from 4 h postinoculation (hpi) ...	2007	17573540
a cyclic amp receptor protein-regulated cell-cell communication system mediates expression of a feca homologue in stenotrophomonas maltophilia.	stenotrophomonas maltophilia wr-c possesses an rpf/diffusible signal factor (dsf) cell-cell communication system. it produces cis-delta2-11-methyl-dodecenoic acid, a dsf, and seven structural derivatives, which require rpff and rpfb for synthesis. acquisition of iron from the environment is important for bacterial growth as well as the expression of virulence genes. we identified a gene homologous to feca, which encodes a ferric citrate receptor that transports exogenous siderophore ferric citra ...	2007	17574998
dual role of ohrr as a repressor and an activator in response to organic hydroperoxides in streptomyces coelicolor.	organic hydroperoxide resistance in bacteria is achieved primarily through reducing oxidized membrane lipids. the soil-inhabiting aerobic bacterium streptomyces coelicolor contains three paralogous genes for organic hydroperoxide resistance: ohra, ohrb, and ohrc. the ohra gene is transcribed divergently from ohrr, which encodes a putative regulator of marr family. both the ohra and ohrr genes were induced highly by various organic hydroperoxides. the ohra gene was induced through removal of repr ...	2007	17586628
estb-mediated hydrolysis of the siderophore triacetylfusarinine c optimizes iron uptake of aspergillus fumigatus.	aspergillus fumigatus excretes the fusarinine-type siderophore desferri-triacetylfusarinine c (df-tafc) to mobilize iron. df-tafc is a cyclic peptide consisting of three n(5)-cis-anhydromevalonyl-n(5)-hydroxy-n(2)-acetyl-l-ornithine residues linked by ester bonds; these linkages are in contrast to peptide linkages found for ferrichrome-type siderophores. subsequent to the binding of iron and uptake, triacetylfusarinine c (tafc) is hydrolyzed, the cleavage products are excreted, and the iron is t ...	2007	17586718
protein subunit interfaces: heterodimers versus homodimers.	protein dimers are either homodimers (complexation of identical monomers) or heterodimers (complexation of non-identical monomers). these dimers are common in catalysis and regulation. however, the molecular principles of protein dimer interactions are difficult to understand mainly due to the geometrical and chemical characteristics of proteins. nonetheless, the principles of protein dimer interactions are often studied using a dataset of 3d structural complexes determined by x-ray crystallogra ...	2005	17597849
arabidopsis thaliana expresses multiple lines of defense to counterattack erwinia chrysanthemi.	many taxonomically diverse plant species are attacked by erwinia chrysanthemi, a member of the causal agents of soft-rotting diseases. symptom development is due to the collective action of pectin-degrading enzymes secreted by the bacterium through a type ii secretion system (t2ss). using arabidopsis thaliana as a susceptible host, we show that plants respond to e. chrysanthemi 3937 by expressing cell-wall reactions, production of an oxidative burst, and activation of salicylic acid (sa) and jas ...	2007	17601167
sucrose-mediated priming of plant defense responses and broad-spectrum disease resistance by overexpression of the maize pathogenesis-related prms protein in rice plants.	expression of pathogenesis-related (pr) genes is part of the plant's natural defense response against pathogen attack. the prms gene encodes a fungal-inducible pr protein from maize. here, we demonstrate that expression of prms in transgenic rice confers broad-spectrum protection against pathogens, including fungal (magnaporthe oryzae, fusarium verticillioides, and helminthosporium oryzae) and bacterial (erwinia chrysanthemi) pathogens. the prms-mediated disease resistance in rice plants is asso ...	2007	17601170
purification and three-dimensional electron microscopy structure of the neisseria meningitidis type iv pilus biogenesis protein pilg.	type iv pili are surface-exposed retractable fibers which play a key role in the pathogenesis of neisseria meningitidis and other gram-negative pathogens. pilg is an integral inner membrane protein and a component of the type iv pilus biogenesis system. it is related by sequence to the extensive gspf family of secretory proteins, which are involved in type ii secretion processes. pilg was overexpressed and purified from escherichia coli membranes by detergent extraction and metal ion affinity ch ...	2007	17616599
the linker region plays a key role in the adaptation to cold of the cellulase from an antarctic bacterium.	the psychrophilic cellulase, cel5g, from the antarctic bacterium pseudoalteromonas haloplanktis is composed of a catalytic module (cm) joined to a carbohydrate-binding module (cbm) by an unusually long, extended and flexible linker region (lr) containing three loops closed by three disulfide bridges. to evaluate the possible role of this region in cold adaptation, the lr was sequentially shortened by protein engineering, successively deleting one and two loops of this module, whereas the last di ...	2007	17635108
comparative genomic reconstruction of transcriptional regulatory networks in bacteria.		2007	17636889
characterization of the erwinia chrysanthemi gan locus, involved in galactan catabolism.	beta-1,4-galactan is a major component of the ramified regions of pectin. analysis of the genome of the plant pathogenic bacteria erwinia chrysanthemi revealed the presence of a cluster of eight genes encoding proteins potentially involved in galactan utilization. the predicted transport system would comprise a specific porin ganl and an abc transporter made of four proteins, ganfgk(2). degradation of galactans would be catalyzed by the periplasmic 1,4-beta-endogalactanase gana, which released o ...	2007	17644603
gliding arc discharge in the potato pathogen erwinia carotovora subsp. atroseptica: mechanism of lethal action and effect on membrane-associated molecules.	gliding arc (glidarc) discharge is a physicochemical technique for decontamination at atmospheric pressure and ambient temperature. it leads to the destruction of bacterial phytopathogens responsible for important losses in industrial agriculture, namely, erwinia spp., without the formation of resistant forms. we investigated the effect of a novel optimized prototype allowing bacterial killing without lag time. this prototype also decreases the required duration of treatment by 50%. the study of ...	2007	17644644
characterization of the osmoprotectant transporter opuc from pseudomonas syringae and demonstration that cystathionine-beta-synthase domains are required for its osmoregulatory function.	the plant pathogen pseudomonas syringae may cope with osmotic stress on plants, in part, by importing osmoprotective compounds. in this study, we found that p. syringae pv. tomato strain dc3000 was distinct from most bacterial species in deriving greater osmoprotection from exogenous choline than from glycine betaine. this superior osmoprotection was correlated with a higher capacity for uptake of choline than for uptake of glycine betaine. of four putative osmoregulatory abc transporters in dc3 ...	2007	17660277
salicylic acid, yersiniabactin, and pyoverdin production by the model phytopathogen pseudomonas syringae pv. tomato dc3000: synthesis, regulation, and impact on tomato and arabidopsis host plants.	a genetically tractable model plant pathosystem, pseudomonas syringae pv. tomato dc3000 on tomato and arabidopsis thaliana hosts, was used to investigate the role of salicylic acid (sa) and iron acquisition via siderophores in bacterial virulence. pathogen-induced sa accumulation mediates defense in these plants, and dc3000 contains the genes required for the synthesis of sa, the sa-incorporated siderophore yersiniabactin (ybt), and the fluorescent siderophore pyoverdin (pvd). we found that dc30 ...	2007	17660289
cochlin in the eye: functional implications.	aqueous humor is actively produced in the ciliary epithelium of the anterior chamber and has important functions for the eye. under normal physiological conditions, the inflow and outflow of the aqueous humor are tightly regulated, but in the pathologic state this balance is lost. aqueous outflow involves structures of the anterior chamber and experiences most resistance at the level of the trabecular meshwork (tm) that acts as a filter. the modulation of the tm structure regulates the filter an ...	2007	17662637
a stress-induced rice (oryza sativa l.) beta-glucosidase represents a new subfamily of glycosyl hydrolase family 5 containing a fascin-like domain.	gh5bg, the cdna for a stress-induced gh5 (glycosyl hydrolase family 5) beta-glucosidase, was cloned from rice (oryza sativa l.) seedlings. the gh5bg cdna encodes a 510-amino-acid precursor protein that comprises 19 amino acids of prepeptide and 491 amino acids of mature protein. the protein was predicted to be extracellular. the mature protein is a member of a plant-specific subgroup of the gh5 exoglucanase subfamily that contains two major domains, a beta-1,3-exoglucanase-like domain and a fasc ...	2007	17705786
molecular basis of the activity of the phytopathogen pectin methylesterase.	we provide a mechanism for the activity of pectin methylesterase (pme), the enzyme that catalyses the essential first step in bacterial invasion of plant tissues. the complexes formed in the crystal using specifically methylated pectins, together with kinetic measurements of directed mutants, provide clear insights at atomic resolution into the specificity and the processive action of the erwinia chrysanthemi enzyme. product complexes provide additional snapshots along the reaction coordinate. w ...	2007	17717531
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
comparative genomic analysis of the tribolium immune system.	tribolium castaneum is a species of coleoptera, the largest and most diverse order of all eukaryotes. components of the innate immune system are hardly known in this insect, which is in a key phylogenetic position to inform us about genetic innovations accompanying the evolution of holometabolous insects. we have annotated immunity-related genes and compared them with homologous molecules from other species.	2007	17727709
virulence and prodigiosin antibiotic biosynthesis in serratia are regulated pleiotropically by the ggdef/eal domain protein, pigx.	gram-negative bacteria of the genus serratia are opportunistic human, plant, and insect pathogens. serratia sp. strain atcc 39006 secretes pectinases and cellulases and produces the secondary metabolites carbapenem and prodigiosin. mutation of a gene (pigx) resulted in an extremely pleiotropic phenotype: prodigiosin antibiotic biosynthesis, plant virulence, and pectinase production were all elevated. pigx controlled secondary metabolism by repressing the transcription of the target prodigiosin b ...	2007	17766413