Publications

a fadd mutant of sinorhizobium meliloti shows multicellular swarming migration and is impaired in nodulation efficiency on alfalfa roots.	swarming is a form of bacterial translocation that involves cell differentiation and is characterized by a rapid and co-ordinated population migration across solid surfaces. we have isolated a tn5 mutant of sinorhizobium meliloti gr4 showing conditional swarming. swarm cells from the mutant strain qs77 induced on semi-solid minimal medium in response to different signals are hyperflagellated and about twice as long as wild-type cells. genetic and physiological characterization of the mutant stra ...	2002	11985715
a r2r3-myb gene, atmyb30, acts as a positive regulator of the hypersensitive cell death program in plants in response to pathogen attack.	hypersensitive response (hr) is a programmed cell death that is commonly associated with disease resistance in plants. among the different hr-related early induced genes, the atmyb30 gene is specifically, rapidly, and transiently expressed during incompatible interactions between arabidopsis and bacterial pathogens. its expression was also shown to be deregulated in arabidopsis mutants affected in the control of cell death initiation. here, we demonstrate that overexpression in arabidopsis and t ...	2002	12119395
characterization of unusual bacteria isolated from respiratory secretions of cystic fibrosis patients and description of inquilinus limosus gen. nov., sp. nov.	using a polyphasic approach (including cellular protein and fatty acid analysis, biochemical characterization, 16s ribosomal dna sequencing, and dna-dna hybridizations), we characterized 51 bacterial isolates recovered from respiratory secretions of cystic fibrosis (cf) patients. our analyses showed that 24 isolates belong to taxa that have so far not (or only rarely) been reported from cf patients. these taxa include acinetobacter sp., bordetella hinzii, burkholderia fungorum, comamonas testost ...	2002	12037065
ppi1: a novel pathogen-induced basic region-leucine zipper (bzip) transcription factor from pepper.	we have isolated a full-length cdna, ppi1 (pepper-pmmv interaction 1), encoding a novel basic region-leucine zipper (bzip) dna-binding protein, from expressed sequence tags differentially expressed in capsicum chinense p1257284 infected with pepper mild mottle virus (pmmv). ppi1 encodes a predicted protein of 170 amino acids and contains a putative dna-binding domain that shares significant amino acid identity with acgt-binding domains of members of the bzip dna-binding protein family. ppi1 was ...	2002	12059102
differential effectiveness of salicylate-dependent and jasmonate/ethylene-dependent induced resistance in arabidopsis.	salicylic acid (sa), jasmonic acid (ja), and ethylene (et) are each involved in the regulation of basal resistance against different pathogens. these three signals play important roles in induced resistance as well. sa is a key regulator of pathogen-induced systemic acquired resistance (sar), whereas ja and et are required for rhizobacteria-mediated induced systemic resistance (isr). both types of induced resistance are effective against a broad spectrum of pathogens. in this study, we compared ...	2002	11858171
rpff mutants of xanthomonas oryzae pv. oryzae are deficient for virulence and growth under low iron conditions.	xanthomonas oryzae pv. oryzae causes bacterial leaf blight, a serious disease of rice. in the related bacterium xanthomonas campestris pv. campestris, the rpff gene is involved in production of a diffusible extracellular factor (dsf) that positively regulates synthesis of virulence-associated functions like extracellular polysaccharide (eps) and extracellular enzymes. transposon insertions in the rpff homolog of x. oryzae pv. oryzae are deficient for virulence and production of a dsf but are pro ...	2002	12036277
the xanthomonas type iii effector protein avrbs3 modulates plant gene expression and induces cell hypertrophy in the susceptible host.	xanthomonas campestris pv. vesicatoria bacteria expressing the type iii effector protein avrbs3 induce a hypersensitive response in pepper plants carrying the resistance gene bs3. here, we report that infection of susceptible pepper and tomato plants leads to an avrbs3-dependent hypertrophy of the mesophyll tissue. agrobacterium-mediated transient expression of the avrbs3 gene in tobacco and potato plants resulted in a similar phenotype. induction of hypertrophy was shown to depend on the repeat ...	2002	12118879
transcription of xanthomonas campestris prt1 gene encoding protease 1 increases during stationary phase and requires global transcription factor clp.	xanthomonas campestris pv. campestris produces three proteases, prt1, prt2, and prt3, the first two of which are involved in pathogenicity. in this study, nucleotide a 84 nt upstream of the prt1 start codon, which is 8 nt downstream of the -10 sequence, was determined as the transcription start site by the 5(') race (rapid amplification of cdna ends) method. using pprt1-lacz transcriptional fusion constructs for assays, several interesting characteristics of prt1 promoter were revealed. the expr ...	2002	12083764
ocatin. a novel tuber storage protein from the andean tuber crop oca with antibacterial and antifungal activities.	the most abundant soluble tuber protein from the andean crop oca (oxalis tuberosa mol.), named ocatin, has been purified and characterized. ocatin accounts for 40% to 60% of the total soluble oca tuber proteins, has an apparent molecular mass of 18 kd and an isoelectric point of 4.8. this protein appears to be found only in tubers and is accumulated only within the cells of the pith and peridermis layers (peel) of the tuber as it develops. ocatin inhibits the growth of several phytopathogenic ba ...	2002	11950978
genetic relationship among worldwide strains of xanthomonas causing canker in citrus species and design of new primers for their identification by pcr.	partial sequence analysis of the ribosomal operon in xanthomonas axonopodis allowed discrimination among strains causing the a, b, and c types of citrus bacterial canker (cbc) and quantification of the relationship of these organisms with other species and pathovars in the same genus. sets of primers based on sequence differences in the internally transcribed spacer and on a sequence from the plasmid gene ptha involved in virulence were designed for specific identification of xanthomonads causin ...	2002	11872476
a gene encoding stellacyanin is induced in capsicum annuum by pathogens, methyl jasmonate, abscisic acid, wounding, drought and salt stress.	a stellacyanin cdna clone (caslp1) was isolated from a pepper cdna library from hypersensitive response (hr) lesions of leaves infected with an avirulent strain of xanthomonas campestris pv. vesicatoria. the deduced amino acid sequences of caslp1 are homologous to those of stellacyanins from cucumber, maize, pea and arabidopsis. the caslp1 mrna was not constitutively expressed in all organs of pepper, but strongly induced and accumulated in pepper tissues infected with x. campestris pv. vesicato ...	2002	12121461
the ohrr repressor senses organic hydroperoxides by reversible formation of a cysteine-sulfenic acid derivative.	reactive oxygen species induce the expression of detoxification and repair genes critical for life in an aerobic environment. bacterial factors that sense reactive oxygen species use either thiol-disulfide exchange reactions (oxyr, rsra) or redox labile 2fe-2s clusters (soxr). we demonstrate that the reduced form of bacillus subtilis ohrr binds cooperatively to two adjacent inverted repeat sequences in the ohra control region and thereby represses transcription. in the presence of organic hydrop ...	2002	11983871
effects of t4 lysozyme release from transgenic potato roots on bacterial rhizosphere communities are negligible relative to natural factors.	rhizosphere bacterial communities of two transgenic potato lines which produce t4 lysozyme for protection against bacterial infections were analyzed in comparison to communities of wild-type plants and transgenic controls not harboring the lysozyme gene. rhizosphere samples were taken from young, flowering, and senescent plants at two field sites in three consecutive years. the communities were characterized in a polyphasic approach. cultivation-dependent methods included heterotrophic plate cou ...	2002	11872484
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
genetic organization of the lexa, reca and recx genes in xanthomonas campestris.	a gene cluster containing lexa, reca and recx genes was previously identified and characterized in xanthomonas campestris pathovar citri (x. c. pv. citri). we have now cloned and sequenced the corresponding regions in the xanthomonas campestris pv. campestris (x. c. pv. campestris) and xanthomonas oryzae pathovar oryzae (x. o. pv. oryzae) chromosome. sequence analysis of these gene clusters showed significant homology to the previously reported lexa, reca and recx genes. the genetic linkage and ...	2002	12007798
molecular identification of family 38 alpha-mannosidase of bacillus sp. strain gl1, responsible for complete depolymerization of xanthan.	when cells of bacillus sp. strain gl1 were grown in a medium containing xanthan as a carbon source, alpha-mannosidase exhibiting activity toward p-nitrophenyl-alpha-d-mannopyranoside (pnp-alpha-d-man) was produced intracellularly. the 350-kda alpha-mannosidase purified from a cell extract of the bacterium was a trimer comprising three identical subunits, each with a molecular mass of 110 kda. the enzyme hydrolyzed pnp-alpha-d-man (km = 0.49 mm) and d-mannosyl-(alpha-1,3)-d-glucose most efficient ...	2002	12039727
comparison of the genomes of two xanthomonas pathogens with differing host specificities.	the genus xanthomonas is a diverse and economically important group of bacterial phytopathogens, belonging to the gamma-subdivision of the proteobacteria. xanthomonas axonopodis pv. citri (xac) causes citrus canker, which affects most commercial citrus cultivars, resulting in significant losses worldwide. symptoms include canker lesions, leading to abscission of fruit and leaves and general tree decline. xanthomonas campestris pv. campestris (xcc) causes black rot, which affects crucifers such a ...	2002	12024217
oric region and replication termination site, dif, of the xanthomonas campestris pv. campestris 17 chromosome.	a 13-kb dna fragment containing oric and the flanking genes thdf, orf900, yidc, rnpa, rpmh, oric, dnaa, dnan, recf, and gyrb was cloned from the gram-negative plant pathogen xanthomonas campestris pv. campestris 17. these genes are conserved in order with other eubacterial oric genes and code for proteins that share high degrees of identity with their homologues, except for orf900, which has a homologue only in xylella fastidiosa. the dnaa/dnan intergenic region (273 bp) identified to be the min ...	2002	12039751
genetic locus encoding functions involved in biosynthesis and outer membrane localization of xanthomonadin in xanthomonas oryzae pv. oryzae.	xanthomonadins are membrane-bound, brominated, aryl-polyene pigments specific to the genus xanthomonas. we have characterized a genetic locus (pig) from xanthomonas oryzae pv. oryzae which contains four open reading frames (orfs) that are essential for xanthomonadin production. three of these orfs are homologous to acyl carrier proteins, dehydratases, and acyl transferases, suggesting a type ii polyketide synthase pathway for xanthomonadin biosynthesis. the fourth orf has no homologue in the dat ...	2002	12057948
osmoregulated periplasmic glucans of the free-living photosynthetic bacterium rhodobacter sphaeroides.	the osmoregulated periplasmic glucans (opgs) produced by rhodobacter sphaeroides, a free-living organism, were isolated by trichloracetic acid treatment and gel permeation chromatography. compounds obtained were characterized by compositional analysis, matrix-assisted laser desorption ionization mass spectrometry and nuclear magnetic resonance. r. sphaeroides predominantly synthesizes a cyclic glucan containing 18 glucose residues that can be substituted by one to seven succinyl esters residues ...	2002	12027884
the rhizobium etli cyac product: characterization of a novel adenylate cyclase class.	adenylate cyclases (acs) catalyze the formation of 3',5'-cyclic amp (camp) from atp. a novel ac-encoding gene, cyac, was isolated from rhizobium etli by phenotypic complementation of an escherichia coli cya mutant. the functionality of the cyac gene was corroborated by its ability to restore camp accumulation in an e. coli cya mutant. further, overexpression of a male::cyac fusion protein allowed the detection of significant ac activity levels in cell extracts of an e. coli cya mutant. cyac is u ...	2002	12057950
genomewide identification of proteins secreted by the hrp type iii protein secretion system of pseudomonas syringae pv. tomato dc3000.	the ability of pseudomonas syringae pv. tomato dc3000 to be pathogenic on plants depends on the hrp (hypersensitive response and pathogenicity) type iii protein secretion system and the effector proteins it translocates into plant cells. through iterative application of experimental and computational techniques, the dc3000 effector inventory has been substantially enlarged. five homologs of known avirulence (avr) proteins and five effector candidates, encoded by genes with putative hrp promoters ...	2002	12032338
a novel type of conserved dna-binding domain in the transcriptional regulators of the algr/agra/lytr family.	sequence analysis of bacterial genomes revealed a novel dna-binding domain. this domain is found in several response regulators of the two-component signal transduction system, such as pseudomonas aeruginosa algr, involved in the regulation of alginate biosynthesis and in the pathogenesis of cystic fibrosis; clostridium perfringens virr, a regulator of virulence factors, and in several regulators of bacteriocin biosynthesis, previously unified in the agra/come family. most of the transcriptional ...	2002	12034833
the role of ethylene and wound signaling in resistance of tomato to botrytis cinerea.	ethylene, jasmonate, and salicylate play important roles in plant defense responses to pathogens. to investigate the contributions of these compounds in resistance of tomato (lycopersicon esculentum) to the fungal pathogen botrytis cinerea, three types of experiments were conducted: (a) quantitative disease assays with plants pretreated with ethylene, inhibitors of ethylene perception, or salicylate; (b) quantitative disease assays with mutants or transgenes affected in the production of or the ...	2002	12114587
direct biochemical evidence for type iii secretion-dependent translocation of the avrbs2 effector protein into plant cells.	the calmodulin-dependent adenylate cyclase domain (cya) of the bordetella pertussis cyclolysin was used as a reporter protein to study the direct translocation of the xanthomonas effector protein, avrbs2, into the plant host cell. adenylate cyclase activity (production of camp) depends on the presence of eukaryotic plant calmodulin and is only active after translocation from the prokaryotic cell into the eukaryotic plant cell. here, we show that infection of pepper plants by xanthomonas campestr ...	2002	12060777
gene discovery within the planctomycete division of the domain bacteria using sequence tags from genomic dna libraries.	the planctomycetes comprise a distinct group of the domain bacteria, forming a separate division by phylogenetic analysis. the organization of their cells into membrane-defined compartments including membrane-bounded nucleoids, their budding reproduction and complete absence of peptidoglycan distinguish them from most other bacteria. a random sequencing approach was applied to the genomes of two planctomycete species, gemmata obscuriglobus and pirellula marina, to discover genes relevant to thei ...	2002	12093378
ubiquitin ligase-associated protein sgt1 is required for host and nonhost disease resistance in plants.	homologues of the yeast ubiquitin ligase-associated protein sgt1 are required for disease resistance in plants mediated by nucleotide-binding site/leucine-rich repeat (nbs-lrr) proteins. here, by silencing sgt1 in nicotiana benthamiana, we extend these findings and demonstrate that sgt1 has an unexpectedly general role in disease resistance. it is required for resistance responses mediated by nbs-lrr and other r proteins in which pathogen-derived elicitors are recognized either inside or outside ...	2002	12119413
molecular cloning and tissue distribution of mammalian l-threonine 3-dehydrogenases.	in mammals, l-threonine is an indispensable amino acid. the conversion of l-threonine to glycine occurs through a two-step biochemical pathway involving the enzymes l-threonine 3-dehydrogenase and 2-amino-3-ketobutyrate coenzyme a ligase. the l-threonine 3-dehydrogenase enzyme has been purified and characterised, but the l-threonine 3-dehydrogenase gene has not previously been identified in mammals.	2002	12097150
a reversibly dissociable ternary complex formed by xpsl, xpsm and xpsn of the xanthomonas campestris pv. campestris type ii secretion apparatus.	the cytoplasmic membrane proteins xpsl, xpsm and xpsn are components required for type ii secretion in xanthomonas campestris pv. campestris. we performed metal-chelating chromatography to partially purify the his(6)-tagged xpsm (xpsmh)-containing complex. immunoblot analysis revealed that both xpsl and xpsn co-eluted with xpsmh. the co-fractionated xpsl and xpsn proteins co-immune precipitated with each other, suggesting the existence of an xpsl-xpsm-xpsn complex. ternary complex formation does ...	2002	12123417
the superantigen gene ypm is located in an unstable chromosomal locus of yersinia pseudotuberculosis.	yersinia pseudotuberculosis produces ypm (y. pseudotuberculosis-derived mitogen), a superantigenic toxin that exacerbates the virulence of the bacterium in vivo. to date, three alleles of the superantigen gene (ypma, ypmb, and ypmc) have been described. these genes are not found in all y. pseudotuberculosis strains and have a low gc content, suggesting their location on mobile genetic elements. to elucidate this question, the genetic environment of the superantigen-encoding genes was characteriz ...	2002	12142419
homologs of the rml enzymes from salmonella enterica are responsible for dtdp-beta-l-rhamnose biosynthesis in the gram-positive thermophile aneurinibacillus thermoaerophilus dsm 10155.	the glycan chains of the surface layer (s-layer) glycoprotein from the gram-positive, thermophilic bacterium aneurinibacillus (formerly bacillus) thermoaerophilus strain dsm 10155 are composed of l-rhamnose- and d-glycero-d-manno-heptose-containing disaccharide repeating units which are linked to the s-layer polypeptide via core structures that have variable lengths and novel o-glycosidic linkages. in this work we investigated the enzymes involved in the biosynthesis of thymidine diphospho-l-rha ...	2002	12147463
comparative genomic analysis of plant-associated bacteria.	this review deals with a comparative analysis of seven genome sequences from plant-associated bacteria. these are the genomes of agrobacterium tumefaciens, mesorhizobium loti, sinorhizobium meliloti, xanthomonas campestris pv campestris, xanthomonas axonopodis pv citri, xylella fastidiosa, and ralstonia solanacearum. genome structure and the metabolism pathways available highlight the compromise between the genome size and lifestyle. despite the recognized importance of the type iii secretion sy ...	2002	12147758
rapd-based genetic linkage maps of yellow passion fruit (passiflora edulis sims. f. flavicarpa deg.).	a single cross between two clones of passion fruit (passiflora edulis sims. f. flavicarpa deg., 2n = 18) was selected for genetic mapping. the mapping population was composed of 90 f1 plants derived from a cross between 'iapar 123' (female parent) and 'iapar 06' (male parent). a total of 380 rapd primers were analyzed according to two-way pseudo-testcross mapping design. the linkage analysis was performed using mapmaker version 3.0 with lod 4.0 and a maximum recombination fraction (theta) of 0.3 ...	2002	12175070
nmr and ms evidences for a random assembled o-specific chain structure in the lps of the bacterium xanthomonas campestris pv. vitians. a case of unsystematic biosynthetic polymerization.	xanthomonas campestris pv. vitians is a gram-negative plant-associated bacterium that acts as causative agent of bacterial leaf spot and headrot in lettuce. the lipopolysaccharide of this bacterium is suspected to be an important molecule for adhesion to and infection of the plants. the lipopolysaccharide has been isolated from the phenol phase and the o-specific chain characterized by compositional analysis, high field nmr and maldi-tof ms. it consists of a nonrepetitive branched polysaccharide ...	2002	12199696
ohrr, a transcription repressor that senses and responds to changes in organic peroxide levels in xanthomonas campestris pv. phaseoli.	we report the physiological role of ohrr as an organic peroxide sensor and transcription repressor in xanthomonas campestris pv. phaseoli. in vivo exposure of x. campestris pv. phaseoli to either tert-butyl or cumene hydroperoxides efficiently neutralized ohrr repression of expression from the ohrr-regulated p1 promoter. h2o2 was a weak and non-physiological inducer of the system while other oxidants and metabolites of organic peroxide metabolism did not induce the expression from the p1. northe ...	2002	12354231
antibiotic use in plant agriculture.	antibiotics have been used since the 1950s to control certain bacterial diseases of high-value fruit, vegetable, and ornamental plants. today, the antibiotics most commonly used on plants are oxytetracycline and streptomycin. in the usa, antibiotics applied to plants account for less than 0.5% of total antibiotic use. resistance of plant pathogens to oxytetracycline is rare, but the emergence of streptomycin-resistant strains of erwinia amylovora, pseudomonas spp., and xanthomonas campestris has ...	2002	12147767
[cloning of xanthomonas campestris pv. campestris pathogenicity-related gene sequences by tail-pcr].	southern blot analysis with probe from mini-tn5 gfp-km transposon indicated that 5 non-pathogenic mutants which were generated by insertion of mini-tn5 gfp-km mutagenesis contained a single copy of the transposon. using genomic dna of each mutant as a template, tail-pcr was performed with seven arbitrary degenerate (ad) primers pairing with 3 nested specific primers designed based on the sequence of gfp toward outside in mini-tn5 gfp-km. after 3-step pcr reactions, the flanking sequence of each ...	2002	12148280
transaldolase exhibits a protective role against menadione toxicity in xanthomonas campestris pv. phaseoli.	a tala gene encoded transaldolase, a rate-limiting enzyme in the non-oxidative branch of the pentose-phosphate pathway, was cloned from xanthomonas campestris pv. phaseoli. tala located in a region of the bacterial genome rich in genes involved in oxidative stress protection and regulation. tala from x. campestris pv. phaseoli showed a high degree of homology to many previously reported transaldolases from both prokaryotic and eukaryotic sources. the expression of x. campestris pv. phaseoli tala ...	2002	12359249
inhibition of hydrolytic enzyme activities and plant pathogen growth by invertase inhibitors.	the invertase inhibitory protein isolated from cyphomandra betacea sendt and solanum tuberosum inhibited the invertase activity from different species, genera and even plant family. furthermore, proteinaceous inhibitors are not invertase specific; fungal, bacterial and higher plant enzymes including polygalacturonase, pectinase, pectin lyase, alpha-l-arabinofuranosidase and beta-glucosidase are also shown to be inhibited. both inhibitors exhibited an in vitro antibacterial action against phytopa ...	2002	12365459
assessment of the importance of similarity in carbon source utilization profiles between the biological control agent and the pathogen in biological control of bacterial speck of tomato.	bacterial speck of tomato, caused by pseudomonas syringae pv. tomato, was used to determine whether similarity in carbon source utilization between a preemptive biological control agent and the pathogen was significant in determining the ability of the bacterium to suppress disease. similarity in carbon source utilization was quantified as the ratio of the number of tomato carbon sources utilized in vitro by the biological control agent to the number of tomato carbon sources utilized in vitro by ...	2002	12200291
whole-genome comparative analysis of three phytopathogenic xylella fastidiosa strains.	xylella fastidiosa (xf) causes wilt disease in plants and is responsible for major economic and crop losses globally. owing to the public importance of this phytopathogen we embarked on a comparative analysis of the complete genome of xf pv citrus and the partial genomes of two recently sequenced strains of this species: xf pv almond and xf pv oleander, which cause leaf scorch in almond and oleander plants, respectively. we report a reanalysis of the previously sequenced xf 9a5c (cvc, citrus) st ...	2002	12205291
complete characterisation of tn5530 from burkholderia cepacia strain 2a (pijb1) and studies of 2,4-dichlorophenoxyacetate uptake by the organism.	the complete genetic characterisation of tn5530 in burkholderia cepacia strain 2a (pijb1) has been accomplished, indicating that it is a tn3-like transposon with a complex structure bearing operons for the catabolism of 2,4-dichlorophenoxyacetate (2,4-d) and malonate. tn5530 is terminated at both ends by the is1071::is1471 element and the 2,4-d- and malonate-dissimilatory operons are separated by a region encoding a puta and lrp gene and a gene encoding a chloride channel protein. the chloride c ...	2002	12206751
type iii secretion systems and the evolution of mutualistic endosymbiosis.	the view that parasites can develop cooperative symbiotic relationships with their hosts is both appealing and widely held; however, there is no molecular genetic evidence of such a transition. here we demonstrate that a mutualistic bacterial endosymbiont of grain weevils maintains and expresses inv/spa genes encoding a type iii secretion system homologous to that used for invasion by bacterial pathogens. phylogenetic analyses indicate that inv/spa genes were present in presymbiotic ancestors of ...	2002	12213957
multidrug pump inhibitors uncover remarkable activity of plant antimicrobials.	plant antimicrobials are not used as systemic antibiotics at present. the main reason for this is their low level of activity, especially against gram-negative bacteria. the reported mic is often in the range of 100 to 1,000 micro g/ml, orders of magnitude higher than those of common broad-spectrum antibiotics from bacteria or fungi. major plant pathogens belong to the gram-negative bacteria, which makes the low level of activity of plant antimicrobials against this group of microorganisms puzzl ...	2002	12234835
lipid peroxidation in cotton: xanthomonas interactions and the role of lipoxygenases during the hypersensitive reaction.	lipid peroxidation, often associated with hypersensitive cell death, may be initiated either by active oxygen species (aos) or lipoxygenases (lox). here we report a detailed analysis of this oxidative process in both incompatible and compatible interactions between the cotton cultivar reba b50 and xanthomonas campestris pv. malvacearum (xcm). the hypersensitive reaction (hr) was characterized by a massive production of polyunsaturated fatty acid (pufa) hydroperoxides together with typical tissue ...	2002	12366796
a hot pepper cdna encoding ascorbate peroxidase is induced during the incompatible interaction with virus and bacteria.	capsicum annuum l. is infected by a number of viruses, including the tobacco mosaic virus (tmv). to study the defense-related genes that are induced by tmv in hot peppers, the pepper plant, which is susceptible to p1.2 but resistant to the p0 pathotype of tmv, was inoculated with tmv-p0. differential screening isolated the genes that were specifically up- or down-regulated during the hypersensitive response (hr). the caapx1 cdna clone that putatively encodes a polypeptide of cytosolic ascorbate ...	2002	12243356
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
structures of the o-polysaccharide chains of the lipopolysaccharides of xanthomonas campestris pv phaseoli var fuscans gspb 271 and x campestris pv malvacearum gspb 1386 and gspb 2388.	o-polysaccharides of phytopathogenic bacteria xanthomonas campestris were isolated by mild acid degradation of the lipopolysaccharides and studied by sugar and methylation analysis, along with 1h and 13c nmr spectroscopy. the following structures of the repeating units of the polysaccharides of x. campestris pv. phaseoli var. fuscans gspb 271 (1). and x. campestris pv. malvacearum gspb 1386 and gspb 2388 (2). were established:the o-polysaccharides of x. campestris are structurally similar to tho ...	2002	12423950
fingerprinting closely related xanthomonas pathovars with random nonamer oligonucleotide microarrays.	current bacterial dna-typing methods are typically based on gel-based fingerprinting methods. as such, they access a limited complement of genetic information and many independent restriction enzymes or probes are required to achieve statistical rigor and confidence in the resulting pattern of dna fragments. furthermore, statistical comparison of gel-based fingerprints is complex and nonstandardized. to overcome these limitations of gel-based microbial dna fingerprinting, we developed a prototyp ...	2002	12450861
the catalytic domains of thiamine triphosphatase and cyab-like adenylyl cyclase define a novel superfamily of domains that bind organic phosphates.	the cyab protein from aeromonas hydrophila has been shown to possess adenylyl cyclase activity. while orthologs of this enzyme have been found in some bacteria and archaea, it shows no detectable relationship to the classical nucleotide cyclases. furthermore, the actual biological functions of these proteins are not clearly understood because they are also present in organisms in which there is no evidence for cyclic nucleotide signaling.	2002	12456267
detection of novel members, structure-function analysis and evolutionary classification of the 2h phosphoesterase superfamily.	2',3' cyclic nucleotide phosphodiesterases are enzymes that catalyze at least two distinct steps in the splicing of trna introns in eukaryotes. recently, the biochemistry and structure of these enzymes, from yeast and the plant arabidopsis thaliana, have been extensively studied. they were found to share a common active site, characterized by two conserved histidines, with the bacterial trna-ligating enzyme ligt and the vertebrate myelin-associated 2',3' phosphodiesterases. using sensitive seque ...	2002	12466548
cloning and sequencing of cdnas for hypothetical genes from chromosome 2 of arabidopsis.	about 25% of the genes in the fully sequenced and annotated arabidopsis genome have structures that are predicted solely by computer algorithms with no support from either nucleic acid or protein homologs from other species or expressed sequence matches from arabidopsis. these are referred to as "hypothetical genes." on chromosome 2, sequenced by the institute for genomic research, there are approximately 800 hypothetical genes among a total of approximately 4,100 genes. to test their expression ...	2002	12481096
isolation and characterization of a porin-like outer membrane protein from xanthomonas campestris pv. campestris.	xanthomonas campestris pv. campestris, a plant-associated pathogenic bacterium, is the causal agent of foliar spots and blights in crucifers. the major outer membrane protein, omp37, of 37 kda, has been identified, purified to homogeneity, and its characterization has also been carried out. native omp37 behaved as a trimer, as revealed by gel filtration and sds-page. ftir measurements revealed a high beta-structure content. the pore-forming ability of the purified omp37 was studied by the liposo ...	2002	12387570
isolation of a xanthomonas campestris strain with elevated beta-galactosidase activity for direct use of lactose in xanthan gum production.	to isolate a xanthomonas campestris strain that can use lactose directly for xanthan gum production.	2002	12390484
ectopic expression of tsi1 in transgenic hot pepper plants enhances host resistance to viral, bacterial, and oomycete pathogens.	in many plants, including hot pepper plants, productivity is greatly affected by pathogen attack. we reported previously that tobacco stress-induced gene 1 (tsi1) may play an important role in regulating stress responsive genes and pathogenesis-related (pr) genes. in this study, we demonstrated that overexpression of tsi1 gene in transgenic hot pepper plants induced constitutive expression of several pr genes in the absence of stress or pathogen treatment. the transgenic hot pepper plants expres ...	2002	12437295
structural and functional characterization of the pseudomonas hydroperoxide resistance protein ohr.	bacteria have developed complex strategies to detoxify and repair damage caused by reactive oxygen species. these compounds, produced during bacterial aerobic respiration as well as by the host immune system cells as a defense mechanism against the pathogenic microorganisms, have the ability to damage nucleic acids, proteins and phospholipid membranes. here we describe the crystal structure of pseudomonas aeruginosa ohr, a member of a recently discovered family of organic hydroperoxide resistanc ...	2002	12485986
evaluation of the roles that alkyl hydroperoxide reductase and ohr play in organic peroxide-induced gene expression and protection against organic peroxides in xanthomonas campestris.	alkyl hydroperoxide reductase (ahpc) and organic hydroperoxide resistance (ohr) are distinct genes, structurally and regulatory, but have similar physiological functions. in xanthomonas campestris pv. phaseoli inactivation of either gene results in increased sensitivity to killing with organic peroxides. an ahpc1-ohr double mutant was highly sensitive to both growth inhibition and killing treatment with organic peroxides. high level expression of ahpc or ohr only partially complemented the pheno ...	2002	12437966
in vivo expression technology.		2002	12438320
molecular diagnostic procedures for production of pathogen-free propagation material.	production of disease-free propagation material is a major means of controlling most bacterial diseases of plants, particularly when neither resistant clones nor effective chemical treatments are available. for this purpose sensitive, specific and rapid detection methods are required. the advent of molecular biology and, in particular, the polymerase chain reaction (pcr) has opened new ways for the characterization and identification of plant pathogens and the development of disease-management s ...	2002	12449531
extracellular arginine aminopeptidase from streptococcus gordonii fss2.	streptococcus gordonii is a primary etiological agent in the development of subacute bacterial endocarditis (sbe), producing thrombus formation and tissue damage on the surfaces of heart valves. this is ironic, considering its normal role as a benign inhabitant of the oral microflora. however, strain fss2 of s. gordonii has been found to produce several extracellular aminopeptidase- and fibrinogen-degrading activities during growth in a ph-controlled batch culture. in this report, we describe th ...	2002	11796618
biosynthesis of a substituted cellulose from a mutant strain of xanthomonas campestris.	in xanthomonas campestris the genes involved in polysaccharide (xanthan) biosynthesis are located in a gene cluster (gum) of 16 kb. a tn5 insertion mutant with a reduced slimy phenotype has been characterized. this mutant failed to produce the pentasaccharide repeating-unit of xanthan. only three sugars were transferred to the prenyl phosphate intermediate. several lines of evidence suggested that the lipid-associated saccharide was the trisaccharide reducing end of the pentasaccharide from the ...	2002	11841812
significance of two distinct types of tryptophan synthase beta chain in bacteria, archaea and higher plants.	tryptophan synthase consists of two subunits, alpha and beta. two distinct subgroups of beta chain exist. the major group (trpeb_1) includes the well-studied beta chain of salmonella typhimurium. the minor group of beta chain (trpeb_2) is most frequently found in the archaea. most of the amino-acid residues important for catalysis are highly conserved between both trpe subfamilies.	2002	11806827
significance of two distinct types of tryptophan synthase beta chain in bacteria, archaea and higher plants.	tryptophan synthase consists of two subunits, alpha and beta. two distinct subgroups of beta chain exist. the major group (trpeb_1) includes the well-studied beta chain of salmonella typhimurium. the minor group of beta chain (trpeb_2) is most frequently found in the archaea. most of the amino-acid residues important for catalysis are highly conserved between both trpe subfamilies.	2002	11806827
two novel type iii-secreted proteins of xanthomonas campestris pv. vesicatoria are encoded within the hrp pathogenicity island.	the hrp type iii protein secretion system (ttss) is essential for pathogenicity of gram-negative plant pathogen xanthomonas campestris pv. vesicatoria. cdna-amplified fragment length polymorphism and reverse transcription-pcr analyses identified new genes, regulated by key hrp regulator hrpg, in the regions flanking the hrp gene cluster. sequence analysis revealed genes encoding hpag, a predicted leucine-rich repeat-containing protein, the lysozyme-like hpah protein, and xopa and xopd, which are ...	2002	11844763
nolx of sinorhizobium fredii usda257, a type iii-secreted protein involved in host range determination, iis localized in the infection threads of cowpea (vigna unguiculata [l.] walp) and soybean (glycine max [l.] merr.) nodules.	sinorhizobium fredii usda257 forms nitrogen-fixing nodules on soybean (glycine max [l.] merr.) in a cultivar-specific manner. this strain forms nodules on primitive soybean cultivars but fails to nodulate agronomically improved north american cultivars. soybean cultivar specificity is regulated by the nolxwbtuv locus, which encodes part of a type iii secretion system (ttss). nolx, a soybean cultivar specificity protein, is secreted by ttss and shows homology to hrpf of the plant pathogen xanthom ...	2002	11790754
structures of the tricorn-interacting aminopeptidase f1 with different ligands explain its catalytic mechanism.	f1 is a 33.5 kda serine peptidase of the alpha/beta-hydrolase family from the archaeon thermoplasma acidophilum. subsequent to proteasomal protein degradation, tricorn generates small peptides, which are cleaved by f1 to yield single amino acids. we have solved the crystal structure of f1 with multiwavelength anomalous dispersion (mad) phasing at 1.8 a resolution. in addition to the conserved catalytic domain, the structure reveals a chiefly alpha-helical domain capping the catalytic triad. thus ...	2002	12374735
getting across--bacterial type iii effector proteins on their way to the plant cell.	pathogenicity of most gram-negative bacterial plant pathogens depends on hrp (hypersensitive response and pathogenicity) genes, which control the ability to cause disease and to elicit specific defense responses in resistant plants. hrp genes encode a specialized type iii secretion (tts) system that mediates the vectorial delivery of bacterial effector proteins across both bacterial membranes as well as across the eukaryotic plasma membrane into the host cell cytosol. one well-studied effector p ...	2002	12374732
molecular characterization of spm-1, a novel metallo-beta-lactamase isolated in latin america: report from the sentry antimicrobial surveillance programme.	the gene encoding the metallo-beta-lactamase spm-1 was cloned from a genomic library of pseudomonas aeruginosa strain 48-1997 a. the insert carrying spm-1 possessed a gc content of 47%, indicating that it is of non-pseudomonas origin. upstream of spm-1 there is a small open reading frame (orf), which is homologous to the lysr family of proteins (69% identity to the lysr protein from salmonella enterica serovar typhimurium). downstream of spm-1 there is the start of an orf, the product of which s ...	2002	12407123
the influence of metabolic network structures and energy requirements on xanthan gum yields.	the metabolic network of xanthomonas campestris is complex since a number of cyclic pathways are present making simple stoichiometric yield predictions difficult. the influence of certain pathway configurations and the resulting variations in flux have been examined as regards the maximum yield potential of this bacteria for xanthan gum production. these predictions have been compared with experimental results showing that the strain employed is functioning close to its theoretical maximum as re ...	2002	12385717
diversity of endophytic bacterial populations and their interaction with xylella fastidiosa in citrus plants.	citrus variegated chlorosis (cvc) is caused by xylella fastidiosa, a phytopathogenic bacterium that can infect all citrus sinensis cultivars. the endophytic bacterial communities of healthy, resistant, and cvc-affected citrus plants were studied by using cultivation as well as cultivation-independent techniques. the endophytic communities were assessed in surface-disinfected citrus branches by plating and denaturing gradient gel electrophoresis (dgge). dominant isolates were characterized by fat ...	2002	12324338
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
construction and characterization of a prou-gfp transcriptional fusion that measures water availability in a microbial habitat.	we constructed and characterized a transcriptional fusion that measures the availability of water to a bacterial cell. this fusion between the prou promoter from escherichia coli and the reporter gene gfp was introduced into strains of e. coli, pantoea agglomerans, and pseudomonas syringae. the prou-gfp fusion in these bacterial biosensor strains responded in a quantitative manner to water deprivation caused by the presence of nacl, na(2)so(4), kcl, or polyethylene glycol (molecular weight, 8000 ...	2002	12200319
gene disruption by homologous recombination in the xylella fastidiosa citrus variegated chlorosis strain.	mutagenesis by homologous recombination was evaluated in xylella fastidiosa by using the bga gene, coding for beta-galactosidase, as a model. integration of replicative plasmids by homologous recombination between the cloned truncated copy of bga and the endogenous gene was produced by one or two crossover events leading to beta-galactosidase mutants. a promoterless chloramphenicol acetyltransferase gene was used to monitor the expression of the target gene and to select a cvab mutant.	2002	12200328
role of oxyr as a peroxide-sensing positive regulator in streptomyces coelicolor a3(2).	genes encoding a homolog of escherichia coli oxyr (oxyr) and an alkyl hydroperoxide reductase system (ahpc and ahpd) have been isolated from streptomyces coelicolor a3(2). the ahpc and ahpd genes constitute an operon transcribed divergently from the oxyr gene. expression of both ahpcd and oxyr genes was maximal at early exponential phase and decreased rapidly as cells entered mid-exponential phase. overproduction of oxyr in streptomyces lividans conferred resistance against cumene hydroperoxide ...	2002	12218006
type iii-dependent translocation of the xanthomonas avrbs3 protein into the plant cell.	many plant pathogenic bacteria utilize a conserved type iii secretion system (ttss) to deliver effector proteins into the host tissue. indirect evidence has suggested that at least some effector proteins are translocated from the bacterial cytoplasm into the plant cell. using an immunocytochemical approach, we demonstrate that the type iii effector avrbs3 from xanthomonas campestris pv. vesicatoria localizes to nuclei of infected pepper leaves. importantly, avrbs3 translocation was observed in s ...	2002	12366827
[a virulence gene from xanthomonas campestris pv. campestris homologous to the avrbs2 locus is recognized in race-specific reaction by two different resistance genes in brassica plant species].	race-specific interaction between the brassica plants and xanthomonas compestris pv. campestris bacteria follows the "gene-for-gene" rule. expression of the avirulence genes recognized by two dominant resistance genes of brassica, rxc1 in plants with the bb genome, and rxc3 in the cc plants, was lost after bacterial mutation in planta. the mutation was distinguished by the elongation of cgcgc pentanucleotide repeat in the gene, which was designated as avrrxc1/3. this gene displayed strong struct ...	2002	12575451
a polyphosphate kinase (ppk2) widely conserved in bacteria.	synthesis of inorganic polyphosphate (poly p) from the terminal phosphate of atp is catalyzed reversibly by poly p kinase (ppk, now designated ppk1) initially isolated from escherichia coli. ppk1 is highly conserved in many bacteria, including some of the major pathogens such as pseudomonas aeruginosa. in a null mutant of p. aeruginosa lacking ppk1, we have discovered a previously uncharacterized ppk activity (designated ppk2) distinguished from ppk1 by the following: synthesis of poly p from gt ...	2002	12486232
relatedness of chromosomal and plasmid dnas of erwinia pyrifoliae and erwinia amylovora.	the plant pathogen erwinia pyrifoliae has been classified as a separate species from erwinia amylovora based in part on differences in molecular properties. in this study, these and other molecular properties were examined for e. pyrifoliae and for additional strains of e. amylovora, including strains from brambles (rubus spp.). the nucleotide composition of the internal transcribed spacer (its) region was determined for six of the seven 16s-23s rrna operons detected in these species with a 16s ...	2002	12450843
coexistence of multiple proteobacterial endosymbionts in the gills of the wood-boring bivalve lyrodus pedicellatus (bivalvia: teredinidae).	wood-boring bivalves of the family teredinidae (commonly called shipworms) are known to harbor dense populations of gram-negative bacteria within specialized cells (bacteriocytes) in their gills. these symbionts are thought to provide enzymes, e.g., cellulase and dinitrogenase, which assist the host in utilizing wood as a primary food source. a cellulolytic, dinitrogen-fixing bacterium, teredinibacter turnerae, has been isolated from the gill tissues of numerous teredinid bivalves and has been p ...	2002	12450854
genetic and phenotypic analysis of acinetobacter baumannii insertion derivatives generated with a transposome system.	acinetobacter baumannii is a metabolically versatile pathogen that causes severe infections in compromised patients. however, little is known about the genes and factors involved in its basic physiology and virulence properties. insertion mutagenesis was used to initiate the identification and characterization of some of these factors and genes in the prototype strain 19606. the utilization of the plofkm suicide delivery vector, which harbors a suicide mini-tn10 derivative, proved to be unsucces ...	2002	12450860
rapid cell death in xanthomonas campestris pv. glycines.	xanthomonas campestris pv. glycines strain am2 (xcgam2), the etiological agent of bacterial pustule disease of soybean, exhibited post-exponential rapid cell death (rcd) in lb medium. x. campestris pv. malvacearum ncim 2310 and x. campestris ncim 2961 also displayed rcd, though less pronouncedly than xcgam2. rcd was not observed in pseudomonas syringae pv. glycines, or escherichia coli dh5alpha. incubation of the post-exponential lb-grown xcgam2 cultures at 4 degrees c arrested the rcd. rcd was ...	2002	12469302
enzymatic synthesis of alpha-arbutin by alpha-anomer-selective glucosylation of hydroquinone using lyophilized cells of xanthomonas campestris wu-9701.	alpha-arbutin, a useful cosmetic ingredient, was selectively synthesized by alpha-anomer-selective glucosylation of hydroquinone with maltose as a glucosyl donor using lyophilized cells of xanthomonas campestris wu-9701 as a biocatalyst. when 45 mm hydroquinone and 120 mg of lyophilized cells showing 11 nkat of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mm h3bo3naohkcl buffer (ph 7.5) containing 1.2 m maltose at 40 degrees c, only one form of hydroquinone glucoside was selectivel ...	2002	16233209
enzymatic synthesis of l-menthyl alpha-maltoside and l-menthyl alpha-maltooligosides from l-menthyl alpha-glucoside by cyclodextrin glucanotransferase.	l-menthyl alpha-d-glucopyranosyl-(1-->4)-alpha-d-glucopyranoside (alpha-meng2), a novel glycoside of l-menthol, was synthesized enzymatically and its physicochemical properties were characterized. production of alpha-meng2 from l-menthyl alpha-d-glucopyranoside (alpha-meng) was attempted since we had already succeeded in the high-yield production of alpha-meng using a xanthomonas campestris enzyme (nakagawa h., et al. j. biosci. bioeng., 89, 138-144, 2000). through production tests on enzymes, i ...	2002	16233280
selective alpha-glucosylation of eugenol by alpha-glucosyl transfer enzyme of xanthomonas campestris wu-9701.	for one-step enzymatic synthesis of eugenyl alpha-glucoside as a promising pro-drug for a hair restorer and a derivative of spices, selective alpha-glucosylation of eugenol was carried out using the alpha-glucosyl transfer enzyme of xanthomonas campestris wu-9701. when 130 micromol eugenol and crude enzyme showing 1.0 unit of alpha-glucosyl transfer activity were shaken in 2 ml of 10 mm h3bo3-naoh-kcl buffer (ph 8.0) containing 1.2 m maltose as a glucosyl donor at 40 degrees c, only one form of ...	2003	16233510
[identification and cloning of a novel gene involved in eps biosynthesis of xanthomonas campestris pv. campestris].	xanthomonas campestris pv. campestris ( xcc), causative agent of the black rot disease of cruciferous crops worldwide, produces large amount of extracellular polysaccharide( eps), which has found wide applications in industry. in order to clone genes involved in eps biosynthesis, xcc wild-type strain 8004 was mutagenized with transposon tn5gus a5, and a number of eps-defective mutants were isolated. the tn5gusa5 insertion sites in the mutants were analyzed by using thermal asymmetric interlaced ...	2003	15971576
the complete genome sequence of chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability.	chromobacterium violaceum is one of millions of species of free-living microorganisms that populate the soil and water in the extant areas of tropical biodiversity around the world. its complete genome sequence reveals (i) extensive alternative pathways for energy generation, (ii) approximately 500 orfs for transport-related proteins, (iii) complex and extensive systems for stress adaptation and motility, and (iv) widespread utilization of quorum sensing for control of inducible systems, all of ...	2003	14500782
concomitant induction of systemic resistance to pseudomonas syringae pv. lachrymans in cucumber by trichoderma asperellum (t-203) and accumulation of phytoalexins.	most studies on the reduction of disease incidence in soil treated with trichoderma asperellum have focused on microbial interactions rather than on plant responses. this study presents conclusive evidence for the induction of a systemic response against angular leaf spot of cucumber (pseudomonas syringae pv. lachrymans) following application of t. asperellum to the root system. to ascertain that t. asperellum was the only microorganism present in the root milieu, plants were grown in an aseptic ...	2003	14660384
genomic approaches in xanthomonas campestris pv. vesicatoria allow fishing for virulence genes.	xanthomonas campestris pv. vesicatoria is an economically important pathogen of pepper and tomato and has been established as a model organism to study bacterial infection strategies. in the last two decades, intensive genetic and molecular analyses led to the isolation of many genes that play a role in the intimate molecular relationship with the host plant. essential for pathogenicity is a type iii protein secretion system, which delivers bacterial effector proteins into the host cell. current ...	2003	14651862
legume symbiotic nitrogen fixation by beta-proteobacteria is widespread in nature.	following the initial discovery of two legume-nodulating burkholderia strains (l. moulin, a. munive, b. dreyfus, and c. boivin-masson, nature 411:948-950, 2001), we identified as nitrogen-fixing legume symbionts at least 50 different strains of burkholderia caribensis and ralstonia taiwanensis, all belonging to the beta-subclass of proteobacteria, thus extending the phylogenetic diversity of the rhizobia. r. taiwanensis was found to represent 93% of the mimosa isolates in taiwan, indicating that ...	2003	14645288
whole genome shotgun sequencing guided by bioinformatics pipelines--an optimized approach for an established technique.	while the sequencing of bacterial genomes has become a routine procedure at major sequencing centers, there are still a number of genome projects at small- or medium-size facilities. for these facilities a maximum of control over sequencing, assembling and finishing is essential. at the same time, facilities have to be able to co-operate at minimum costs for the overall project. we have established a pipeline for the distributed sequencing of alcanivorax borkumensis sk2, azoarcus sp. bh72, clavi ...	2003	14651855
metagenome survey of biofilms in drinking-water networks.	most naturally occurring biofilms contain a vast majority of microorganisms which have not yet been cultured, and therefore we have little information on the genetic information content of these communities. therefore, we initiated work to characterize the complex metagenome of model drinking water biofilms grown on rubber-coated valves by employing three different strategies. first, a sequence analysis of 650 16s rrna clones indicated a high diversity within the biofilm communities, with the ma ...	2003	14660379
fimx, a multidomain protein connecting environmental signals to twitching motility in pseudomonas aeruginosa.	twitching motility is a form of surface translocation mediated by the extension, tethering, and retraction of type iv pili. three independent tn5-b21 mutations of pseudomonas aeruginosa with reduced twitching motility were identified in a new locus which encodes a predicted protein of unknown function annotated pa4959 in the p. aeruginosa genome sequence. complementation of these mutants with the wild-type pa4959 gene, which we designated fimx, restored normal twitching motility. fimx mutants we ...	2003	14645265
characterization of two antagonistic strains of rahnella aquatilis isolated from soil in egypt.	in an attempt to obtain biological control agents for controlling bacterial spot of cucumber, over 250 bacterial strains were isolated from agricultural soil samples, collected from different localities in giza governorate (egypt) and screened for in vitro antibiosis towards xanthomonas campestris. only 2 strains showed antagonistic activity. they and their culture filtrates restricted the growth of a number of g- and g(+)-indicator bacteria. on chrome azurol s agar, both strains exhibited a mar ...	2003	15058195
catalytic mechanism of thiol peroxidase from escherichia coli. sulfenic acid formation and overoxidation of essential cys61.	escherichia coli thiol peroxidase (tpx, p20, scavengase) is part of an oxidative stress defense system that uses reducing equivalents from thioredoxin (trx1) and thioredoxin reductase to reduce alkyl hydroperoxides. tpx contains three cys residues, cys(95), cys(82), and cys(61), and the latter residue aligns with the n-terminal active site cys of other peroxidases in the peroxiredoxin family. to identify the catalytically important cys, we have cloned and purified tpx and four mutants (c61s, c82 ...	2003	12514184
plant lectin-like bacteriocin from a rhizosphere-colonizing pseudomonas isolate.	rhizosphere isolate pseudomonas sp. strain bw11m1, which belongs to the pseudomonas putida cluster, secretes a heat- and protease-sensitive bacteriocin which kills p. putida gr12-2r3. the production of this bacteriocin is enhanced by dna-damaging treatment of producer cells. we isolated a tnmod mutant of strain bw11m1 that had lost the capacity to inhibit the growth of strain gr12-2r3. a wild-type genomic fragment encompassing the transposon insertion site was shown to confer the bacteriocin phe ...	2003	12533465
a colonization factor (production of lateral flagella) of mesophilic aeromonas spp. is inactive in aeromonas salmonicida strains.	the nine laf (lateral flagellum) genes of mesophilic aeromonads are in the aeromonas salmonicida genome. the laf genes are functional, except for lafa (flagellin gene), which was inactivated by transposase 8 (is3 family). a pathogenic characteristic of mesophilic aeromonads (lateral flagella) is abolished in this specialized pathogen with a narrow host range.	2003	12514057
glutathione s-transferase isoenzymes from streptomyces griseus.	an inducible, cytosolic glutathione s-transferase (gst) was purified from streptomyces griseus. gst isoenzymes with pi values of 6.8 and 7.9 used standard gst substrates including 1-chloro-2,4-dinitrobenzene. gst had subunit and native m(r)s of 24 and 48, respectively, and the n-terminal sequence smilxywdiirglpah.	2003	12514067
identification of the pepper sar8.2 gene as a molecular marker for pathogen infection, abiotic elicitors and environmental stresses in capsicum annuum.	pepper ( capsicum annuum l.) sar8.2 genes, designated casar82a, b and c, which are induced by all the biotic and abiotic stresses, were isolated from a pepper cdna library constructed with the mrnas from pepper plants infected with xanthomonas campestris pv. vesicatoria. the pepper casar82a, b and c gene products, which are very similar to each other in amino acid sequences, have 43-50% homology with those of tobacco sar8.2 genes. the casar8.2 genes were not constitutively expressed in any of th ...	2003	12520329
recombination activity of a distinctive integron-gene cassette system associated with pseudomonas stutzeri populations in soil.	class 1 integrons have strongly influenced the evolution of multiple antibiotic resistance. diverse integrons have recently been detected directly in a range of natural environments. in order to characterize the properties of these environmental integrons, we sought to isolate organisms containing integrons from soils, which resulted in the isolation of pseudomonas stutzeri strain q. further isolation efforts targeted at this species resulted in recovery of two other strains (p and bam). 16s rrn ...	2003	12533467
comparative analyses of the complete genome sequences of pierce's disease and citrus variegated chlorosis strains of xylella fastidiosa.	xylella fastidiosa is a xylem-dwelling, insect-transmitted, gamma-proteobacterium that causes diseases in many plants, including grapevine, citrus, periwinkle, almond, oleander, and coffee. x. fastidiosa has an unusually broad host range, has an extensive geographical distribution throughout the american continent, and induces diverse disease phenotypes. previous molecular analyses indicated three distinct groups of x. fastidiosa isolates that were expected to be genetically divergent. here we r ...	2003	12533478