Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| diversity of polyamine patterns in soft rot pathogens and other plant-associated members of the enterobacteriaceae. | polyamine profiles of 91 pectolytic and other plant-associated strains from 30 taxa of the enterobacteriaceae were obtained by gradient high performance liquid chromatography (hplc). pectobacterium carotovorum, basonym erwinia carotovora, contained a high amount of putrescine and less diaminopropane. diaminopropane was absent in pectobacterium chrysanthemi, basonym e. chrysanthemi, whereas cadaverine was present in addition to the major compound putrescine. this chemotaxonomic difference reflect ... | 2001 | 11403399 |
| identification of proteus mirabilis mutants with increased sensitivity to antimicrobial peptides. | antimicrobial peptides (aps) are important components of the innate defenses of animals, plants, and microorganisms. however, some bacterial pathogens are resistant to the action of aps. for example, proteus mirabilis is highly resistant to the action of aps, such as polymyxin b (pm), protegrin, and the synthetic protegrin analog ib-367. to better understand this resistance, a transposon mutagenesis approach was used to generate p. mirabilis mutants sensitive to aps. four unique pm-sensitive mut ... | 2001 | 11408219 |
| backbone h(n), n, calpha, c' and cbeta assignment of the 25 kda peptide methionine sulfoxide reductase from erwinia chrysanthemi. | 2001 | 11430764 | |
| listeria pathogenesis and molecular virulence determinants. | the gram-positive bacterium listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. listeriosis can also manifest as a febrile gastroente ... | 2001 | 11432815 |
| complex regulation of the organic hydroperoxide resistance gene (ohr) from xanthomonas involves ohrr, a novel organic peroxide-inducible negative regulator, and posttranscriptional modifications. | analysis of the sequence immediate upstream of ohr revealed an open reading frame, designated ohrr, with the potential to encode a 17-kda peptide with moderate amino acid sequence homology to the marr family of negative regulators of gene expression. ohrr was transcribed as bicistronic mrna with ohr, while ohr mrna was found to be 95% monocistronic and 5% bicistronic with ohrr. expression of both genes was induced by tert-butyl hydroperoxide (tbooh) treatment. high-level expression of ohrr negat ... | 2001 | 11443074 |
| novel topology of bfpe, a cytoplasmic membrane protein required for type iv fimbrial biogenesis in enteropathogenic escherichia coli. | enteropathogenic escherichia coli (epec) produces the bundle-forming pilus (bfp), a type iv fimbria that has been implicated in virulence, autoaggregation, and localized adherence to epithelial cells. the bfpe gene is one of a cluster of bfp genes previously shown to encode functions that direct bfp biosynthesis. here, we show that an epec strain carrying a nonpolar mutation in bfpe fails to autoaggregate, adhere to hep-2 cells, or form bfp, thereby demonstrating that bfpe is required for bfp bi ... | 2001 | 11443077 |
| the type iv fimbrial subunit gene (fima) of dichelobacter nodosus is essential for virulence, protease secretion, and natural competence. | dichelobacter nodosus is the essential causative agent of footrot in sheep. the major d. nodosus-encoded virulence factors that have been implicated in the disease are type iv fimbriae and extracellular proteases. to examine the role of the fimbriae in virulence, allelic exchange was used to insertionally inactivate the fima gene, which encodes the fimbrial subunit protein, from the virulent type g d. nodosus strain vcs1703a. detailed analysis of two independently derived fima mutants revealed t ... | 2001 | 11443078 |
| dna microarray-mediated transcriptional profiling of the escherichia coli response to hydrogen peroxide. | the genome-wide transcription profile of escherichia coli cells treated with hydrogen peroxide was examined with a dna microarray composed of 4,169 e. coli open reading frames. by measuring gene expression in isogenic wild-type and oxyr deletion strains, we confirmed that the peroxide response regulator oxyr activates most of the highly hydrogen peroxide-inducible genes. the dna microarray measurements allowed the identification of several new oxyr-activated genes, including the hemh heme biosyn ... | 2001 | 11443091 |
| extracellular polysaccharides of modified strains of erwinia spp. | the structure of the extracellular polysaccharide (eps) produced by erwinia chrysanthemi strain a2148 has been determined using low pressure size-exclusion and anion-exchange chromatographies, high ph anion-exchange chromatography, glycosyl-linkage analysis, and 1d 1h nmr spectroscopy. the polysaccharide is structurally similar, if not identical, to the eps produced by e. chrysanthemi strain a350. a streptomycin-resistant strain of e. chrysanthemi ech6 (ech6s(+)) has been generated and has an el ... | 2001 | 11454336 |
| structure-function analysis of bfpb, a secretin-like protein encoded by the bundle-forming-pilus operon of enteropathogenic escherichia coli. | production of type iv bundle-forming pili by enteropathogenic escherichia coli (epec) requires bfpb, an outer-membrane lipoprotein and member of the secretin protein superfamily. bfpb was found to compose a ring-shaped, high-molecular-weight outer-membrane complex that is stable in 4% sodium dodecyl sulfate at temperatures of < or = 65 degrees c. chemical cross-linking and immunoprecipitation experiments disclosed that the bfpb multimeric complex interacts with bfpg, and mutational studies showe ... | 2001 | 11466288 |
| identification and functional characterization of cbar, a marr-like modulator of the cbaabc-encoded chlorobenzoate catabolism pathway. | in comamonas testosteroni br60 (formerly alcaligenes sp. strain br60), catabolism of the pollutant 3-chlorobenzoate (3cba) is initiated by enzymes encoded by cbaabc, an operon found on composite transposon tn5271 of plasmid pbrc60. the cbaabc gene product cbaabc converts 3cba to protocatechuate (pca) and 5-cl-pca, which are then metabolized by the chromosomal pca meta (extradiol) ring fission pathway. in this study, cbaa was found to possess a sigma(70) type promoter. o(2) uptake experiments wit ... | 2001 | 11472929 |
| gene cluster for assembly of pilus colonization factor antigen iii of enterotoxigenic escherichia coli. | the assembly of pilus colonization factor antigen iii (cfa/iii) of enterotoxigenic escherichia coli (etec) requires the processing of cfa/iii major pilin (cofa) by a prepilin peptidase (cofp), similar to other type iv pilus formation systems. cofa is produced initially as a 26.5-kda preform pilin (prepilin) and then processed to a 20.5-kda mature pilin by cofp which is predicted to be localized in the inner membrane. in the present experiment, we determined the nucleotide sequence of the whole r ... | 2001 | 11500465 |
| type ii protein secretion in gram-negative pathogenic bacteria: the study of the structure/secretion relationships of the cellulase cel5 (formerly egz) from erwinia chrysanthemi. | erwinia chrysanthemi, a gram-negative plant pathogen, secretes the cellulase cel5 (formerly egz) via the type ii secretion pathway (referred to as out). cel5 is composed of two domains, a large n-terminal catalytic domain (390 amino acid residues) and a small c-terminal cellulose-binding domain (62 amino acid residues) separated by a linker region. a combination of mutagenesis and structural analysis permitted us to investigate the structure/secretion relationships with respect to the catalytic ... | 2001 | 11501995 |
| the relationship between the l1 and l2 domains of the insulin and epidermal growth factor receptors and leucine-rich repeat modules. | leucine-rich repeats are one of the more common modules found in proteins. the leucine-rich repeat consensus motif is lxxlxlxxnxlxxlxxlxxlxx- where the first 11-12 residues are highly conserved and the remainder of the repeat can vary in size leucine-rich repeat proteins have been subdivided into seven subfamilies, none of which include members of the epidermal growth factor receptor or insulin receptor families despite the similarity between the 3d structure of the l domains of the type i insul ... | 2001 | 11504559 |
| low-temperature lipase from psychrotrophic pseudomonas sp. strain kb700a. | we have previously reported that a psychrotrophic bacterium, pseudomonas sp. strain kb700a, which displays sigmoidal growth even at -5 degrees c, produced a lipase. a genomic dna library of strain kb700a was introduced into escherichia coli tg1, and screening on tributyrin-containing agar plates led to the isolation of the lipase gene. sequence analysis revealed an open reading frame (kb-lip) consisting of 1,422 nucleotides that encoded a protein (kb-lip) of 474 amino acids with a molecular mass ... | 2001 | 11526006 |
| enhancer-binding proteins hrpr and hrps interact to regulate hrp-encoded type iii protein secretion in pseudomonas syringae strains. | in pseudomonas syringae strains, the hrp-hrc pathogenicity island consists of an hrpl-dependent regulon that encodes a type iii protein translocation complex and translocated effector proteins required for pathogenesis. hrpr and hrps function as positive regulatory factors for the hrpl promoter, but their mechanism of action has not been established. both hrpr and hrps are structurally related to enhancer-binding proteins, but they lack receiver domains and do not appear to require a cognate pro ... | 2001 | 11544221 |
| peptide methionine sulfoxide reductase (msra) is a virulence determinant in mycoplasma genitalium. | mycoplasma genitalium is the smallest self-replicating microorganism and is implicated in human diseases, including urogenital and respiratory infections and arthritides. m. genitalium colonizes host cells primarily through adherence mechanisms mediated by a network of surface-associated membrane proteins, including adhesins and cytadherence-related proteins. in this paper, we show that cytadherence in m. genitalium is affected by an unrelated protein known as peptide methionine sulfoxide reduct ... | 2001 | 11544227 |
| cloning and characterization of an intracellular isoamylase gene from pectobacterium chrysanthemi py35. | the gene encoding an intracellular isoamylase from the pectobacterium chrysanthemi py35 was cloned in escherichia coli dh5alpha and sequenced. the isoamylase gene (amyx) had an open reading frame of 1974 bp encoding 657 amino acid residues with a calculated molecular weight of 74,151 da. the molecular weight of the enzyme was also estimated to be 74 kda by activity staining of a sds-pa gel. isoamylase from p. chrysanthemi py35 had 59% pairwise amino acid identity with glycogen debranching enzyme ... | 2001 | 11554733 |
| identification of togmnab, an abc transporter which mediates the uptake of pectic oligomers in erwinia chrysanthemi 3937. | the bacterium erwinia chrysanthemi, which causes soft rot disease on various plants, is able to use pectin as a carbon source for growth. knowledge of the critical step in pectin catabolism which allows the entry of pectic oligomers into the cells is scarce. we report here the first example of a transport system involved in the uptake of pectic oligomers. the togmnab transporter of e. chrysanthemi is a member of the atp-binding cassette (abc) superfamily. togm and togn are homologous to the inne ... | 2001 | 11555291 |
| two transporters, togt and togmnab, are responsible for oligogalacturonide uptake in erwinia chrysanthemi 3937. | erwinia chrysanthemi causes soft rot of plants by secreting pectinases which cleave pectin, a polysaccharide cementing the plant cell wall constituents. we demonstrated that two transporters mediate the uptake of the extracellularly formed oligomers in e. chrysanthemi. togmnab, a multicomponent transporter member of the atp-binding cassette (abc) superfamily, is only partially responsible for the uptake of pectic oligomers. its action is completed by that of the second transporter, togt, a membe ... | 2001 | 11555292 |
| nonspecific adherence and fibril biogenesis by actinobacillus actinomycetemcomitans: tada protein is an atpase. | cells of actinobacillus actinomycetemcomitans, a gram-negative pathogen responsible for an aggressive form of juvenile periodontitis, form tenaciously adherent biofilms on solid surfaces. the bacteria produce long fibrils of bundled pili, which are required for adherence. mutations in flp-1, which encodes the major subunit of the pili, or any of seven downstream tad genes (tadabcdefg) cause defects in fibril production, autoaggregation, and tenacious adherence. we proposed that the tad genes spe ... | 2001 | 11566992 |
| genetic organization of the pantoea stewartii subsp. stewartii hrp gene cluster and sequence analysis of the hrpa, hrpc, hrpn, and wtse operons. | the hrp/wts gene cluster of pantoea stewartii subsp. stewartii is required for pathogenicity on sweet corn and the ability to elicit a hypersensitive response (hr) in tobacco. site-directed transposon mutagenesis and nucleotide sequencing were used to identify hrp/wts genes within the left 20 kb of this cluster. seventeen open reading frames (orfs) comprise seven genetic complementation groups. these orfs share homology with hrp and dsp genes from erwinia amylovora, erwinia chrysanthemi, and pse ... | 2001 | 11605961 |
| monitoring of erwinia asparaginase therapy in childhood all in the nordic countries. | evaluation of l-asparaginase therapy in the nopho-92 all-protocol (treatment protocol of acute lymphoblastic leukaemia of the nordic society of paediatric haematology and oncology, initiated in 1992) after intravenous and intramuscular administration of erwinia asparaginase during induction and re-induction therapy. | 2001 | 11678787 |
| glycine betaine loses its osmoprotective activity in a bspa strain of erwinia chrysanthemi. | erwinia chrysanthemi insertion mutants were isolated that grew poorly specifically in the presence of glycine betaine (gb) or its analogues in high-salt media. transposon insertions were found to affect the bspa gene, which forms an operon including the psd locus coding for phosphatidylserine decarboxylase. initial gb uptake is not affected by the bspa mutation. however, in high-salt medium, its initial accumulation is followed by a reduced glucose uptake and a release of gb but not a loss of vi ... | 2001 | 11679069 |
| input of protein to lake water microcosms affects expression of proteolytic enzymes and the dynamics of pseudomonas spp. | the objective of this study was to determine how an input of protein to lake water affects expression of a proteolytic potential and influences the abundance and composition of a specific group of bacteria. pseudomonas spp. were chosen as a target group that can be recovered on selective growth media and contain both proteolytic and nonproteolytic strains. amendment with 2 mg of casein per liter increased total proteinase activity (hydrolysis of [(3)h]casein) by 74%, leucine-aminopeptidase activ ... | 2001 | 11679313 |
| identification and characterization of the three chitin-binding domains within the multidomain chitinase chi92 from aeromonas hydrophila jp101. | the gene (chi92) encoding the extracellular chitinase of aeromonas hydrophila jp101 has been cloned and expressed in escherichia coli. the mature form of chi92 is an 842-amino-acid (89.830-kda) modular enzyme comprised of a family 18 catalytic domain, an unknown-function region (the a region), and three chitin-binding domains (chbds; chi92-n, chbd(ci), and chbd(cii)). the c-terminally repeated chbds, chbd(ci) and chbd(cii), were grouped into family v of cellulose-binding domains on the basis of ... | 2001 | 11679332 |
| comparative evaluation of pectolytic and proteolytic enzyme production by free and immobilized cells of some strains of the phytopathogenic erwinia chrysanthemi. | whole cells of the phytopathogenic erwinia chrysanthemi strains were immobilized in k-carrageenan and grown in high-calcium xanthomonas campestris medium containing sodium polypectate as carbon source. all the strains used survived immobilization into k-carrageenan beads. immobilized e. chrysanthemi strains displayed higher pectolytic and proteolytic enzyme activities than free cells in liquid suspension. carrageenan immobilization techniques could provide a system to mimic the conditions of e. ... | 2001 | 11687933 |
| a partially folded intermediate conformation is induced in pectate lyase c by the addition of 8-anilino-1-naphthalenesulfonate (ans). | addition of 8-anilino-1-naphthalenesulfonate (ans) to acid-denatured pectate lyase c (pelc) leads to a large increase in the fluorescence quantum yield near 480 nm. the conventional interpretation of such an observation is that the ans is binding to a partially folded intermediate such as a molten globule. far-ultraviolet circular dichroism demonstrates that the enhanced fluorescence results from the induction of a partially folded protein species that adopts a large fraction of native-like seco ... | 2001 | 11567103 |
| chrysobactin-dependent iron acquisition in erwinia chrysanthemi. functional study of a homolog of the escherichia coli ferric enterobactin esterase. | under iron limitation, the plant pathogen erwinia chrysanthemi produces the catechol-type siderophore chrysobactin, which acts as a virulence factor. it can also use enterobactin as a xenosiderophore. we began this work by sequencing the 5'-upstream region of the fct-cbsceba operon, which encodes the ferric chrysobactin receptor and proteins involved in synthesis of the catechol moiety. we identified a new iron-regulated gene (cbsh) transcribed divergently relative to the fct gene, the translate ... | 2002 | 11694506 |
| duplicate copies of genes encoding methanesulfonate monooxygenase in marinosulfonomonas methylotropha strain tr3 and detection of methanesulfonate utilizers in the environment. | marinosulfonomonas methylotropha strain tr3 is a marine methylotroph that uses methanesulfonic acid (msa) as a sole carbon and energy source. the genes from m. methylotropha strain tr3 encoding methanesulfonate monooxygenase, the enzyme responsible for the initial oxidation of msa to formaldehyde and sulfite, were cloned and sequenced. they were located on two gene clusters on the chromosome of this bacterium. a 5.0-kbp hindiii fragment contained msma, msmb, and msmc, encoding the large and smal ... | 2002 | 11772638 |
| the oligogalacturonate-specific porin kdgm of erwinia chrysanthemi belongs to a new porin family. | the phytopathogenic gram-negative bacteria erwinia chrysanthemi secretes pectinases, which are able to degrade the pectic polymers of plant cell walls, and uses the degradation products as a carbon source for growth. we characterized a major outer membrane protein, kdgm, whose synthesis is strongly induced in the presence of pectic derivatives. the corresponding gene was characterized. analysis of transcriptional fusions showed that the kdgm expression is controlled by the general repressor of p ... | 2002 | 11773048 |
| genes required for plasmid r64 thin-pilus biogenesis: identification and localization of products of the pilk, pilm, pilo, pilp, pilr, and pilt genes. | we have previously shown that the pill, piln, pilq, pils, pilu, and pilv genes of plasmid r64 encode outer membrane lipoprotein, secretin, cytoplasmic atpase, major pilin, prepilin peptidase, and minor pilin, respectively, which are required for thin-pilus formation. in this work, we characterized the products of the remaining essential genes, pilk, pilm, pilo, pilp, pilr, and pilt, with regard to their localization and processing. overexpression systems containing pilm, pilo, and pilp genes fus ... | 2002 | 11751821 |
| cloning of the cel8y gene from pectobacterium chrysanthemi py35 and its comparison to cel genes of soft-rot pectobacterium. | the phytopathogenic pectobacterium chrysanthemi (pch) py35 secretes multiple isozymes of plant cell wall degrading enzyme cellulases. we cloned a second cel gene that encodes cellulase in pch py35. the inserted 2 kb fragment was subcloned in order to geneate ppy710 (cel8y). the structural organization of the cel8y gene consists of an open reading frame (orf) of 999 bp that encodes 332 amino acid residues with a signal peptide of 23 amino acids. the predicted amino acid sequence of cel8y was very ... | 2002 | 11911471 |
| bacillus subtilis 168 contains two differentially regulated genes encoding l-asparaginase. | expression of the two bacillus subtilis genes encoding l-asparaginase is controlled by independent regulatory factors. the ansz gene (formerly yccc) was shown by mutational analysis to encode a functional l-asparaginase, the expression of which is activated during nitrogen-limited growth by the tnra transcription factor. gel mobility shift and dnase i footprinting experiments indicate that tnra regulates ansz expression by binding to a dna site located upstream of the ansz promoter. the expressi ... | 2002 | 11914346 |
| use of the caulobacter crescentus genome sequence to develop a method for systematic genetic mapping. | the functional analysis of sequenced genomes will be facilitated by the development of tools for the rapid mapping of mutations. we have developed a systematic approach to genetic mapping in caulobacter crescentus that is based on bacteriophage-mediated transduction of strategically placed antibiotic resistance markers. the genomic dna sequence was used to identify sites distributed evenly around the chromosome at which plasmids could be nondisruptively integrated. dna fragments from these sites ... | 2002 | 11914347 |
| the extracellular transport signal of the vibrio cholerae endochitinase (chia) is a structural motif located between amino acids 75 and 555. | chia, an 88-kda endochitinase encoded by the chia gene of the gram-negative enteropathogen vibrio cholerae, is secreted via the eps-encoded main terminal branch of the general secretory pathway (gsp), a mechanism which also transports cholera toxin. to localize the extracellular transport signal of chia that initiates transport of the protein through the gsp, a chimera comprised of chia fused at the n terminus with the maltose-binding protein (male) of escherichia coli and fused at the c terminu ... | 2002 | 11914354 |
| application of amplified fragment length polymorphism fingerprinting for taxonomy and identification of the soft rot bacteria erwinia carotovora and erwinia chrysanthemi. | the soft rot bacteria erwinia carotovora and erwinia chrysanthemi are important pathogens of potato and other crops. however, the taxonomy of these pathogens, particularly at subspecies level, is unclear. an investigation using amplified fragment length polymorphism (aflp) fingerprinting was undertaken to determine the taxonomic relationships within this group based on their genetic relatedness. following cluster analysis on the similarity matrices derived from the aflp gels, four clusters (clus ... | 2002 | 11916661 |
| the ybit gene of erwinia chrysanthemi codes for a putative abc transporter and is involved in competitiveness against endophytic bacteria during infection. | we investigated the role in bacterial infection of a putative abc transporter, designated ybit, of erwinia chrysanthemi ac4150. the deduced sequence of this gene showed amino acid sequence similarity with other putative abc transporters of gram-negative bacteria, such as escherichia coli and pseudomonas aeruginosa, as well as structural similarity with proteins of streptomyces spp. involved in resistance to macrolide antibiotics. the gene contiguous to ybit, designated as pab (putative antibioti ... | 2002 | 11916677 |
| identification of quorum-quenching n-acyl homoserine lactonases from bacillus species. | a range of gram-negative bacterial species use n-acyl homoserine lactone (ahl) molecules as quorum-sensing signals to regulate different biological functions, including production of virulence factors. ahl is also known as an autoinducer. an autoinducer inactivation gene, aiia, coding for an ahl lactonase, was cloned from a bacterial isolate, bacillus sp. strain 240b1. here we report identification of more than 20 bacterial isolates capable of enzymatic inactivation of ahls from different source ... | 2002 | 11916693 |
| h-ns-dependent activation of pectate lyases synthesis in the phytopathogenic bacterium erwinia chrysanthemi is mediated by the pect repressor. | production of the main virulence determinant pectate lyases (pels) of the phytopathogenic bacterium erwinia chrysanthemi is modulated by a complex regulatory network involving the repressor proteins kdgr, pecs and pect and the activator systems pir, expi-expr and crp. of these regulators, crp and pect are particularly important since the absence of crp or a slight overproduction of pect leads to a drastic reduction in synthesis of pel species. recently, it has been shown that production of pel s ... | 2002 | 11929528 |
| comparison of escherichia coli-asparaginase with erwinia-asparaginase in the treatment of childhood lymphoid malignancies: results of a randomized european organisation for research and treatment of cancer-children's leukemia group phase 3 trial. | asparaginase is an enzyme used in the treatment of acute lymphoblastic leukemia and lymphoblastic lymphoma in children. it has minimal bone marrow toxicity. its major side effects are anaphylaxis, pancreatitis, diabetes, coagulation abnormalities, and thrombosis, especially intracranial. it is derived from 2 different sources: escherichia coli and erwinia chrysanthemi. nonrandomized clinical studies have suggested a similar efficacy of these 2 types of asparaginases and a lower toxicity for erwi ... | 2002 | 11929760 |
| extracellular polysaccharides of a bacterium associated with a fungal canker disease of eucalyptus sp. | extracellular polysaccharides (epss) produced by an erwinia sp associated with a fungal canker disease of eucalyptus were fractionated into one polysaccharide that was identified with that produced by erwinia chrysanthemi strains sr260, ech1, and ech9, and the other distinctively different from any other eps produced by e. chrysanthemi strains so far studied. their structures were determined using a combination of chemical and physical techniques including methylation analysis, low pressure gel- ... | 2002 | 11950469 |
| solution structure of the lict-rna antitermination complex: cat clamping rat. | lict is a bacterial regulatory protein able to prevent the premature arrest of transcription. when activated, lict binds to a 29 base rna hairpin overlapping a terminator located in the 5' mrna leader region of the target genes. we have determined the solution structure of the lict rna-binding domain (cat) in complex with its ribonucleic antiterminator (rat) target by nmr spectroscopy (pdb 1l1c). cat is a beta-stranded homodimer that undergoes no important conformational changes upon complex for ... | 2002 | 11953318 |
| pehn, a polygalacturonase homologue with a low hydrolase activity, is coregulated with the other erwinia chrysanthemi polygalacturonases. | erwinia chrysanthemi 3937 secretes an arsenal of pectinolytic enzymes, including at least eight endo-pectate lyases encoded by pel genes, which play a major role in the soft-rot disease caused by this bacterium on various plants. e. chrysanthemi also produces some hydrolases that cleave pectin. three adjacent hydrolase genes, pehv, pehw, and pehx, encoding exo-poly-alpha-d-galacturonosidases, have been characterized. these enzymes liberate digalacturonides from the nonreducing end of pectin. we ... | 2002 | 11976295 |
| the refolding of type ii shikimate kinase from erwinia chrysanthemi after denaturation in urea. | shikimate kinase was chosen as a convenient representative example of the subclass of alpha/beta proteins with which to examine the mechanism of protein folding. in this paper we report on the refolding of the enzyme after denaturation in urea. as shown by the changes in secondary and tertiary structure monitored by far uv circular dichroism (cd) and fluorescence, respectively, the enzyme was fully unfolded in 4 m urea. from an analysis of the unfolding curve in terms of the two-state model, the ... | 2002 | 11985590 |
| new type of osmoregulated solute transporter identified in halophilic members of the bacteria domain: trap transporter teaabc mediates uptake of ectoine and hydroxyectoine in halomonas elongata dsm 2581(t). | the halophilic bacterium halomonas elongata synthesizes as its main compatible solute the aspartate derivative ectoine. we constructed a deletion mutant of h. elongata, kb1, defective in ectoine synthesis and tolerating elevated salt concentrations only in the presence of external compatible solutes. the dependency of kb1 on solute uptake for growth in high-salt medium was exploited to select insertion mutants unable to accumulate external solutes via osmoregulated transporters. one insertion mu ... | 2002 | 12003950 |
| the crystal structure of hypothetical protein mth1491 from methanobacterium thermoautotrophicum. | as part of our structural proteomics initiative, we have determined the crystal structure of mth1491, a previously uncharacterized hypothetical protein from methanobacterium thermoautotrophicum. mth1491 is one of numerous structural genomics targets selected in a genome-wide survey of uncharacterized proteins. it belongs to a family of proteins whose biological function is not known. the crystal structure of mth1491, the first structure for this family of proteins, consists of an overall five-st ... | 2002 | 12021439 |
| hrp genes of erwinia chrysanthemi 3937 are important virulence factors. | we developed improved virulence assays for erwinia chrysanthemi 3937 on african violet varieties and devised a new method for the construction of precise bacterial gene knockouts. these methods were tested by constructing mutations in genes suspected to be involved with plant interactions. the virulence of the hrpg and hrcc mutant strains (both gene products presumed to be involved in protein secretion) was greatly reduced on leaves of semitolerant african violet varieties. an hrpn mutant strain ... | 2002 | 12036278 |
| structure of pectate lyase a: comparison to other isoforms. | pectate lyase a is a virulence factor secreted by the plant-pathogenic bacteria erwinia chrysanthemi. the enzyme cleaves the glycosidic bond of pectate polymers by a calcium-dependent beta-elimination mechanism. the crystal structure of pectate lyase a from e. chrysanthemi ec16 has been determined in two crystal forms, monoclinic c2 to 1.8 a and rhombohedral r3 to 2.1 a. the protein structure is compared with two other pectate lyase isoforms from e. chrysanthemi ec16, pectate lyase c and pectate ... | 2002 | 12037303 |
| decreasing the level of ethyl acetate in ethanolic fermentation broths of escherichia coli ko11 by expression of pseudomonas putida estz esterase. | during the fermentation of sugars to ethanol relatively high levels of an undesirable coproduct, ethyl acetate, are also produced. with ethanologenic escherichia coli strain ko11 as the biocatalyst, the level of ethyl acetate in beer containing 4.8% ethanol was 192 mg liter(-1). although the e. coli genome encodes several proteins with esterase activity, neither wild-type strains nor ko11 contained significant ethyl acetate esterase activity. a simple method was developed to rapidly screen bacte ... | 2002 | 12039716 |
| crystal structure of shikimate kinase from mycobacterium tuberculosis reveals the dynamic role of the lid domain in catalysis. | shikimate kinase (sk) and other enzymes in the shikimate pathway are potential targets for developing non-toxic antimicrobial agents, herbicides, and anti-parasite drugs, because the pathway is essential in the above species but is absent from mammals. the crystal structure of mycobacterium tuberculosis sk (mtsk) in complex with mgadp has been determined at 1.8 a resolution, revealing critical information for the structure-based design of novel anti-m. tuberculosis agents. mtsk, with a five-stra ... | 2002 | 12054870 |
| differential regulation of multiple proteins of escherichia coli and salmonella enterica serovar typhimurium by the transcriptional regulator slya. | slya is a transcriptional regulator of escherichia coli, salmonella enterica, and other bacteria belonging to the enterobacteriaceae: the slya protein has been shown to be involved in the virulence of s. enterica serovar typhimurium, but its role in e. coli is unclear. in this study, we employed the proteome technology to analyze the slya regulons of enteroinvasive e. coli (eiec) and salmonella serovar typhimurium. in both cases, comparative analysis of the two-dimensional protein maps of a wild ... | 2002 | 12057949 |
| variable surface protein vmm of mycoplasma mycoides subsp. mycoides small colony type. | a variable surface protein, vmm, of the bovine pathogen mycoplasma mycoides subsp. mycoides small colony type (m. mycoides sc) has been identified and characterized. vmm was specific for the sc biotype and was expressed by 68 of 69 analyzed m. mycoides sc strains. the protein was found to undergo reversible phase variation at a frequency of 9 x 10(-4) to 5 x 10(-5) per cell per generation. the vmm gene was present in all of the 69 tested m. mycoides sc strains and encodes a lipoprotein precursor ... | 2002 | 12057968 |
| identification of xcpp domains that confer functionality and specificity to the pseudomonas aeruginosa type ii secretion apparatus. | gram-negative bacteria have evolved several types of secretion mechanisms to release proteins into the extracellular medium. one such mechanism, the type ii secretory system, is a widely conserved two-step process. the first step is the translocation of signal peptide-bearing exoproteins across the inner membrane. the second step, the translocation across the outer membrane, involves the type ii secretory apparatus or secreton. the secretons are made up of 12-15 proteins (gsp) depending on the o ... | 2002 | 12067351 |
| [isolation and genetic study of erwinia mutants devoid of common components of the phosphoenolpyruvate-dependent phosphotransferase system]. | mutants of bacteria belonging the genus erwinia (erwinia chrysanthemi and erwinia carotovora) with pleiotropic disturbances in the utilization of many substrates were obtained through chemical and transposon mutagenesis. genetic studies revealed that these mutants had defective ptsi or ptsh genes responsible for the synthesis of common components of the phosphoenolpyruvate-dependent phosphotransferase system, enzyme i and the hpr protein, respectively. the ptsi+ allele in both erwinia species wa ... | 2002 | 12068545 |
| export of l-isoleucine from corynebacterium glutamicum: a two-gene-encoded member of a new translocator family. | bacteria possess amino acid export systems, and corynebacterium glutamicum excretes l-isoleucine in a process dependent on the proton motive force. in order to identify the system responsible for l-isoleucine export, we have used transposon mutagenesis to isolate mutants of c. glutamicum sensitive to the peptide isoleucyl-isoleucine. in one such mutant, strong peptide sensitivity resulted from insertion into a gene designated brnf encoding a hydrophobic protein predicted to possess seven transme ... | 2002 | 12081967 |
| in situ transfer of antibiotic resistance genes from transgenic (transplastomic) tobacco plants to bacteria. | interkingdom gene transfer is limited by a combination of physical, biological, and genetic barriers. the results of greenhouse experiments involving transplastomic plants (genetically engineered chloroplast genomes) cocolonized by pathogenic and opportunistic soil bacteria demonstrated that these barriers could be eliminated. the acinetobacter sp. strain bd413, which is outfitted with homologous sequences to chloroplastic genes, coinfected a transplastomic tobacco plant with ralstonia solanacea ... | 2002 | 12089013 |
| altering plant-microbe interaction through artificially manipulating bacterial quorum sensing. | many bacteria regulate diverse physiological processes in concert with their population size. bacterial cell-to-cell communication utilizes small diffusible signal molecules, which the bacteria both produce and perceive. the bacteria couple gene expression to cell density by eliciting a response only when the signalling molecules reach a critical threshold (a point at which the population is said to be 'quorate'). the population as a whole is thus able to modify its behaviour as a single unit. a ... | 2002 | 12096736 |
| genomic and functional analyses of sxt, an integrating antibiotic resistance gene transfer element derived from vibrio cholerae. | sxt is representative of a family of conjugative-transposon-like mobile genetic elements that encode multiple antibiotic resistance genes. in recent years, sxt-related conjugative, self-transmissible integrating elements have become widespread in asian vibrio cholerae. we have determined the 100-kb dna sequence of sxt. this element appears to be a chimera composed of transposon-associated antibiotic resistance genes linked to a variety of plasmid- and phage-related genes, as well as to many gene ... | 2002 | 12107144 |
| identification of chromosomal shigella flexneri genes induced by the eukaryotic intracellular environment. | upon entry into the eukaryotic cytosol, the facultative intracellular bacterium shigella flexneri is exposed to an environment that may necessitate the expression of particular genes for it to survive and grow intracellularly. to identify genes that are induced in response to the intracellular environment, we screened a library containing fragments of the s. flexneri chromosome fused to a promoterless green fluorescent protein gene (gfp). bacteria containing promoter fusions that had a higher le ... | 2002 | 12117948 |
| diverse bacteria are pathogens of caenorhabditis elegans. | practically and ethically attractive as model systems, invertebrate organisms are increasingly recognized as relevant for the study of bacterial pathogenesis. we show here that the nematode caenorhabditis elegans is susceptible to a surprisingly broad range of bacteria and may constitute a useful model for the study of both pathogens and symbionts. | 2002 | 12117988 |
| microarray profiling of erwinia chrysanthemi 3937 genes that are regulated during plant infection. | microarray technology was used to identify genes in erwinia chrysanthemi 3937 that are specifically up- or down-regulated in a plant host compared with growth in laboratory culture medium. several genes were plant down-regulated, and almost all of them were homologues of well-known housekeeping genes, such as those encoding metabolic functions, oxidative phosphorylation components, and transcription or translation processes. on the other hand, almost all of the plant up-regulated genes were invo ... | 2002 | 12118877 |
| suppressive subtractive hybridization detects extensive genomic diversity in thermotoga maritima. | comparisons between genomes of closely related bacteria often show large variations in gene content, even between strains of the same species. such studies have focused mainly on pathogens; here, we examined thermotoga maritima, a free-living hyperthermophilic bacterium, by using suppressive subtractive hybridization. the genome sequence of t. maritima msb8 is available, and dna from this strain served as a reference to obtain strain-specific sequences from thermotoga sp. strain rq2, a very clos ... | 2002 | 12142418 |
| mutational analysis of the tola c-terminal domain of escherichia coli and genetic evidence for an interaction between tola and tolb. | the tol proteins are involved in the outer membrane stability of gram-negative bacteria. the c-terminal domain of tola was mutagenized to identify residues important for its functions. the isolation of suppressor mutants of tola mutations in the tolb gene confirmed an interaction between tolaiii and the n-terminal domain of tolb. | 2002 | 12142433 |
| inhibition of the plastidic atp/adp transporter protein primes potato tubers for augmented elicitation of defense responses and enhances their resistance against erwinia carotovora. | tubers of transgenic potato (solanum tuberosum) plants with decreased activity of the plastidic atp/adp transporter aatp1 display reduced levels of starch, modified tuber morphology, and altered concentrations of primary metabolites. here, we demonstrate that the spontaneous production of hydrogen peroxide, the endogenous content of salicylic acid, and the levels of mrnas of various defense-related genes are similar in tuber discs of wild-type and aatp1(st) antisense plants. however, upon challe ... | 2002 | 12177473 |
| biodegradation of the polyketide toxin cercosporin. | cercosporin is a non-host-specific polyketide toxin produced by many species of plant pathogens belonging to the genus cercospora. this red-pigmented, light-activated toxin is an important pathogenicity determinant for cercospora species. in this study, we screened 244 bacterial isolates representing 12 different genera for the ability to degrade cercosporin. cercosporin degradation was determined by screening for the presence of cleared zones surrounding colonies on cercosporin-containing cultu ... | 2002 | 12200262 |
| convergent evolution sheds light on the anti-beta -elimination mechanism common to family 1 and 10 polysaccharide lyases. | enzyme-catalyzed beta-elimination of sugar uronic acids, exemplified by the degradation of plant cell wall pectins, plays an important role in a wide spectrum of biological processes ranging from the recycling of plant biomass through to pathogen virulence. the three-dimensional crystal structure of the catalytic module of a "family pl-10" polysaccharide lyase, pel10acm from cellvibrio japonicus, solved at a resolution of 1.3 a, reveals a new polysaccharide lyase fold and is the first example of ... | 2002 | 12221284 |
| heca, a member of a class of adhesins produced by diverse pathogenic bacteria, contributes to the attachment, aggregation, epidermal cell killing, and virulence phenotypes of erwinia chrysanthemi ec16 on nicotiana clevelandii seedlings. | erwinia chrysanthemi is representative of a broad class of bacterial pathogens that are capable of inducing necrosis in plants. the e. chrysanthemi ec16 heca gene predicts a 3,850-aa member of the bordetella pertussis filamentous hemagglutinin family of adhesins. a hecatn7 mutant was reduced in virulence on nicotiana clevelandii seedlings after inoculation without wounding. epifluorescence and confocal laser-scanning microscopy observations of heca and wild-type cells expressing the green fluore ... | 2002 | 12271135 |
| beta-aspartylpeptides as substrates of l-asparaginases from escherichia coli and erwinia chrysanthemi. | l-asparaginase is known to catalyze the hydrolysis of l-asparagine to l-aspartic and ammonia, but little is known about its action on peptides. when we incubated l-asparaginases purified either from escherichia coli or erwinia chrysanthemi - commonly used as chemotherapeutic agents because of their antitumour activity - with eight small beta-aspartylpeptides such as beta-aspartylserineamide, beta-aspartylalanineamide, beta-aspartylglycineamide and beta-aspartylglycine, we found that both l-aspar ... | 2002 | 12297292 |
| analytical validation of a microplate reader-based method for the therapeutic drug monitoring of l-asparaginase in human serum. | the enzyme l-asparaginase (asnase), which hydrolyzes l-asparagine (l-asn) to ammonia and l-aspartic acid (l-asp), is commonly used for remission induction in acute lymphoblastic leukemia. to correlate asnase activity with l-asn reduction in human serum, sensitive methods for the determination of asnase activity are required. using l-aspartic beta-hydroxamate (aha) as substrate we developed a sensitive plate reader-based method for the quantification of asnase derived from escherichia coli and er ... | 2002 | 12381370 |
| characterization of serracin p, a phage-tail-like bacteriocin, and its activity against erwinia amylovora, the fire blight pathogen. | serratia plymithicum j7 culture supernatant displayed activity against many pathogenic strains of erwinia amylovora, the causal agent of the most serious bacterial disease of apple and pear trees, fire blight, and against klebsiella pneumoniae, serratia liquefaciens, serratia marcescens, and pseudomonas fluorescens. this activity increased significantly upon induction with mitomycin c. a phage-tail-like bacteriocin, named serracin p, was purified from an induced culture supernatant of s. plymith ... | 2002 | 12406768 |
| coupling of iron assimilation and pectinolysis in erwinia chrysanthemi 3937. | two major virulence determinants of the plant-pathogenic enterobacterium erwinia chrysanthemi strain 3937 are the production of pectate lyase enzymes that degrade plant cell walls and expression of two high-affinity iron uptake systems mediated by two structurally unrelated siderophores, chrysobactin and achromobactin. low iron availability is a signal that triggers transcription of the genes encoding pectate lyases peld and pele as well as that of genes involved in iron transport. this metallor ... | 2002 | 12423024 |
| direct structure determination using residual dipolar couplings: reaction-site conformation of methionine sulfoxide reductase in solution. | residual dipolar couplings (rdc) from partially aligned molecules provide long-range structural data and are thus particularly well adapted to rapid structure validation or protein fold recognition. extensive measurements in two alignment media can also provide precise de novo structure from rdc alone. we have applied a novel combination of these approaches to the study of methionine sulfoxide reductase (msra) from erwinia chrysanthemi, a 27 kda enzyme essential for repairing oxidative stress da ... | 2002 | 12431100 |
| characterization of indigoidine biosynthetic genes in erwinia chrysanthemi and role of this blue pigment in pathogenicity. | in the plant-pathogenic bacterium erwinia chrysanthemi production of pectate lyases, the main virulence determinant, is modulated by a complex network involving several regulatory proteins. one of these regulators, pecs, also controls the synthesis of a blue pigment identified as indigoidine. since production of this pigment is cryptic in the wild-type strain, e. chrysanthemi ind mutants deficient in indigoidine synthesis were isolated by screening a library of tn5-b21 insertions in a pecs mutan ... | 2002 | 11790734 |
| osmotically regulated synthesis of the compatible solute ectoine in bacillus pasteurii and related bacillus spp. | by using natural-abundance (13)c-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography (hplc) analysis we have investigated the types of compatible solutes that are synthesized de novo in a variety of bacillus species under high-osmolality growth conditions. five different patterns of compatible solute production were found among the 13 bacillus species we studied. bacillus subtilis, b. licheniformis, and b. megaterium produced proline; b. cereus, b. circulans, b. th ... | 2002 | 11823218 |
| genotyping of bacteria belonging to the former erwinia genus by pcr-rflp analysis of a reca gene fragment. | genotypic characterization, based on the analysis of restriction fragment length polymorphism of the reca gene fragment pcr product (reca pcr-rflp), was performed on members of the former erwinia genus. pcr primers deduced from published reca gene sequences of erwinia carotovora allowed the amplification of an approximately 730 bp dna fragment from each of the 19 erwinia species tested. amplified reca fragments were compared using rflp analysis with four endonucleases (alui, hinfi, tasi and tru1 ... | 2002 | 11832521 |
| manipulation of strawberry fruit softening by antisense expression of a pectate lyase gene. | strawberry (fragaria x ananassa, duch., cv chandler) is a soft fruit with a short postharvest life, mainly due to a rapid lost of firm texture. to control the strawberry fruit softening, we obtained transgenic plants that incorporate an antisense sequence of a strawberry pectate lyase gene under the control of the 35s promoter. forty-one independent transgenic lines (apel lines) were obtained, propagated in the greenhouse for agronomical analysis, and compared with control plants, non-transforme ... | 2002 | 11842178 |
| yopd and lcrh regulate expression of yersinia enterocolitica yopq by a posttranscriptional mechanism and bind to yopq rna. | pathogenic yersiniae secrete 14 yop proteins via the type iii pathway. synthesis of yopq occurs when the type iii machinery is activated by a low-calcium signal, but not when the calcium concentration is above 100 microm. to characterize the mechanism that regulates the expression of yopq, mutants that permit synthesis of yopq in the presence of calcium were isolated. yersiniae bearing deletion mutations in yopn, tyea, sycn, or yscb synthesized and secreted yopq in both the presence and the abse ... | 2002 | 11844757 |
| activity enhancement of cel5z from pectobacterium chrysanthemi py35 by removing c-terminal region. | the phytopathogenic bacterium pectobacteium chrysanthemi py35 secretes cel5z endoglucanase belonging to the glycoside hydrolase family 5 of ec 3.2.1.4. the mutation of cel5z::omega gene was constructed by cloning the 2.0-kb smai fragment containing the streptomycin/spectinomycin-resistance gene of php45(omega) into the bali site of ppy100. the insertion of omega fragment generated a new stop codon, removing the ser/thr-rich linker region and the cellulose binding domain (cbd) in the c-terminal r ... | 2002 | 11846423 |
| purification and characterization of an extracellular protease from xenorhabdus nematophila involved in insect immunosuppression. | xenorhabdus nematophila, a bacterium pathogenic for insects associated with the nematode steinernema carpocapsae, releases high quantities of proteases, which may participate in the virulence against insects. zymogram assays and cross-reactions of antibodies suggested that two distinct proteases were present. the major one, protease ii, was purified and shown to have a molecular mass of 60 kda and an estimated isoelectric point of 8.5. protease ii digested the chromogenic substrate n-tosyl-gly-p ... | 2002 | 11872480 |
| identification of xcpz domains required for assembly of the secreton of pseudomonas aeruginosa. | most of the exoproteins secreted by pseudomonas aeruginosa are transported via the type ii secretion system. this machinery, which is widely conserved in gram-negative bacteria, consists of 12 xcp proteins organized as a multiprotein complex, also called the secreton. we previously reported that the mutual stabilization of xcpz and xcpy plays an important role in the assembly of the secreton. in this study, we engineered variant xcpz proteins by using linker insertion mutagenesis. we identified ... | 2002 | 11872731 |
| crystal structure of thermotoga maritima 0065, a member of the iclr transcriptional factor family. | members of the iclr family of transcription regulators modulate signal-dependent expression of genes involved in carbon metabolism in bacteria and archaea. the thermotoga maritima tm0065 gene codes for a protein (tm-iclr) that is homologous to the iclr family. we have determined the crystal structure of tm-iclr at 2.2 a resolution using mad phasing and synchrotron radiation. the protein is composed of two domains: the n-terminal dna-binding domain contains the winged helix-turn-helix motif, and ... | 2002 | 11877432 |
| molecular analysis of the gene encoding a novel chitin-binding protease from alteromonas sp. strain o-7 and its role in the chitinolytic system. | alteromonas sp. strain o-7 secretes several proteins in response to chitin induction. we have found that one of these proteins, designated apriv, is a novel chitin-binding protease involved in chitinolytic activity. the gene encoding apriv (apriv) was cloned in escherichia coli. dna sequencing analysis revealed that the open reading frame of apriv encoded a protein of 547 amino acids with a calculated molecular mass of 57,104 da. apriv is a modular enzyme consisting of five domains: the signal s ... | 2002 | 11889092 |
| snakin-2, an antimicrobial peptide from potato whose gene is locally induced by wounding and responds to pathogen infection. | the peptide snakin-2 (stsn2) has been isolated from potato (solanum tuberosum cv jaerla) tubers and found to be active (ec(50) = 1-20 microm) against fungal and bacterial plant pathogens. it causes a rapid aggregation of both gram-positive and gram-negative bacteria. the corresponding stsn2 cdna encodes a signal sequence followed by a 15-residue acidic sequence that precedes the mature stsn2 peptide, which is basic (isoelectric point = 9.16) and 66 amino acid residues long (molecular weight of 7 ... | 2002 | 11891250 |
| the n terminus of the hasa protein and the secb chaperone cooperate in the efficient targeting and secretion of hasa via the atp-binding cassette transporter. | secretion of the hasa hemophore is mediated by a c-terminal secretion signal as part of an atp-binding cassette (abc) pathway in the gram-negative bacterium serratia marcescens. we reconstituted the hasa secretion pathway in escherichia coli. in e. coli, this pathway required three specific secretion functions and secb, the general chaperone of the sec pathway that recognizes hasa. the secretion of the isolated c-terminal secretion signal was not secb-dependent. we have previously shown that int ... | 2002 | 11698405 |
| microbial cellulose utilization: fundamentals and biotechnology. | fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. the methodological basis for studying microbial cellulose utilization is considered relative to qu ... | 2002 | 12209002 |
| erwinia chrysanthemi genes specifically induced during infection in chicory leaves. | summary twelve erwinia chrysanthemi genes specifically up-regulated during infection in chicory leaves have been identified using gus reporter gene fusions. according to sequence comparisons with genbank databases, the possible functions of the identified genes included: virulence, adaptation to apoplast environment, chemotaxis, transposition, regulation, and metabolic functions. the level of gene up-regulation in planta was measured, and ranged from 1.39 to 47.11 times that found in liquid cult ... | 2002 | 20569334 |
| molecular basis of bacterial outer membrane permeability revisited. | gram-negative bacteria characteristically are surrounded by an additional membrane layer, the outer membrane. although outer membrane components often play important roles in the interaction of symbiotic or pathogenic bacteria with their host organisms, the major role of this membrane must usually be to serve as a permeability barrier to prevent the entry of noxious compounds and at the same time to allow the influx of nutrient molecules. this review summarizes the development in the field since ... | 2003 | 14665678 |
| [purification and properties of recombinant erwinia carotovora l-asparaginase expressed in e.coli cells]. | the method of purification erwinia carotovora recombinant l-asparaginase, expressed in e.coli, including ultrasonic disintegration of biomass, fractionation ammonium sulfate and column chromatography on cm- or sp-sepharose has been developed. according to sds-paage the enzyme preparation was homogeneous, its specific activity and yield consist respectively about 620 iu/mg of protein and 75%. physical-chemical and structural properties of recombinant erwinia carotovora l-asparaginase are similar ... | 2003 | 16119104 |
| cloning and characterization of the glycogen branching enzyme gene existing in tandem with the glycogen debranching enzyme from pectobacterium chrysanthemi py35. | the glycogen branching enzyme gene (glgb) from pectobacterium chrysanthemi py35 was cloned, sequenced, and expressed in escherichia coli. the glgb gene consisted of an open reading frame of 2196bp encoding a protein of 731 amino acids (calculated molecular weight of 83,859da). the glgb gene is upstream of glgx and the orf starts the atg initiation codon and ends with the tga stop codon at 2bp upstream of glgx. the enzyme was 43-69% sequence identical with other glycogen branching enzymes. the en ... | 2003 | 12480526 |
| the secb chaperone is bifunctional in serratia marcescens: secb is involved in the sec pathway and required for hasa secretion by the abc transporter. | hasa is the secreted hemophore of the heme acquisition system (has) of serratia marcescens. it is secreted by a specific abc transporter apparatus composed of three proteins: hasd, an inner membrane abc protein; hase, another inner membrane protein; and hasf, a tolc homolog. except for hasf, the structural genes of the has system are encoded by an iron-regulated operon. in previous studies, this secretion system has been reconstituted in escherichia coli, where it requires the presence of the se ... | 2003 | 12486043 |
| oxyr acts as a repressor of catalase expression in neisseria gonorrhoeae. | it has been reported that neisseria gonorrhoeae possesses a very high level of catalase activity, but the regulation of catalase expression has not been investigated extensively. in escherichia coli and salmonella enterica serovar typhimurium, it has been demonstrated that oxyr is a positive regulator of hydrogen peroxide-inducible genes, including the gene encoding catalase. the oxyr gene from n. gonorrhoeae was cloned and used to complement an e. coli oxyr mutant, confirming its identity and f ... | 2003 | 12496210 |
| atomic resolution structure of erwinia chrysanthemi l-asparaginase. | an x-ray structure of l-asparaginase from erwinia chrysanthemi (era) has been refined at 1 a resolution to an r factor of below 0.1, using data collected on a synchrotron source. with four molecules of the enzyme consisting of 327 amino acids each, this crystal contains one of the largest asymmetric units of a protein refined to date at atomic resolution. previously, structures of era and of related enzymes from other bacterial sources have been refined at resolutions not exceeding 1.7 a; thus, ... | 2003 | 12499544 |
| functional and mutational analysis of conjugative transfer region 2 (tra2) from the inchi1 plasmid r27. | the transfer 2 region (tra2) of the conjugative plasmid drr27 (derepressed r27) was analyzed by psi-blast, insertional mutagenesis, genetic complementation, and an h-pilus assay. tra2 contains 11 mating-pair formation (mpf) genes that are essential for conjugative transfer, 9 of which are essential for h-pilus production (trha, -l, -e, -k, -b, -v, -c, -p, and -w). trhk has similarity to secretin proteins, suggesting a mechanism by which dna could traverse the outer membrane of donors. the remain ... | 2003 | 12511505 |
| degradation and transformability of dna from transgenic leaves. | the fate of transplastomic (chloroplast genome contains the transgene) tobacco plant dna in planta was studied when the plant leaves were subjected to decay conditions simulating those encountered naturally, including grinding, incubation with cellulase or enzymes produced by erwinia chrysanthemi, and attack by the plant pathogen ralstonia solanacearum. direct visualization of dna on agarose gels, gene extraction yield (the number of amplifiable aada sequences in extracted plant dna), and the fr ... | 2003 | 12514059 |
| asap, a systematic annotation package for community analysis of genomes. | asap (a systematic annotation package for community analysis of genomes) is a relational database and web interface developed to store, update and distribute genome sequence data and functional characterization (https://asap.ahabs.wisc.edu/annotation/php/asap1.htm). asap facilitates ongoing community annotation of genomes and tracking of information as genome projects move from preliminary data collection through post-sequencing functional analysis. the asap database includes multiple genome seq ... | 2003 | 12519969 |
| characterization and implications of ca2+ binding to pectate lyase c. | ca(2+) is essential for in vitro activity of erwinia chrysanthemi pectate lyase c (pelc). crystallographic analyses of 11 pelc-ca(2+) complexes, formed at ph 4.5, 9.5, and 11.2 under varying ca(2+) concentrations, have been solved and refined at a resolution of 2.2 a. the ca(2+) site represents a new motif for ca(2+), consisting primarily of beta-turns and beta-strands. the principal differences between pelc and the pelc-ca(2+) structures at all ph values are the side-chain conformations of asp- ... | 2003 | 12540845 |
| sufc: an unorthodox cytoplasmic abc/atpase required for [fe-s] biogenesis under oxidative stress. | proteins containing [fe-s] clusters perform essential functions in all domains of life. previously, we identified the sufabcdse operon as being necessary for virulence of the plant pathogen erwinia chrysanthemi. in addition, we collected preliminary evidence that the sufabcdse operon might be involved in the assembly of [fe-s] clusters. of particular interest are the sufb, sufc and sufd genes, which are conserved among eubacteria, archaea, plants and parasites. the present study establishes sufc ... | 2003 | 12554644 |
| yfik from escherichia coli promotes export of o-acetylserine and cysteine. | yfik was discovered as a gene augmenting cysteine production when it was overexpressed in an industrial escherichia coli production strain. the gene product is an integral membrane protein with about six predicted transmembrane helices; it belongs to the rhtb family of export proteins. yfik overproduction from a plasmid leads to drastic and parallel secretion of o-acetylserine and cysteine into the medium but only when the organism possesses a serine transacetylase that is feedback insensitive t ... | 2003 | 12562784 |
| overrepresentation of a gene family encoding extracytoplasmic solute receptors in bordetella. | a family of genes that are likely to encode extracytoplasmic solute receptors is strongly overrepresented in several beta-proteobacteria, including bordetella pertussis. this gene family, of which members have been called bug genes, contains some examples that are contained within polycistronic operons coding for tripartite uptake transporters of the ttt family, while the vast majority are "orphan" genes. proteomic and functional analyses demonstrated that several of these genes are expressed in ... | 2003 | 12562821 |