| nopl, an effector protein of rhizobium sp. ngr234, thwarts activation of plant defense reactions. | bacterial effector proteins delivered into eukaryotic cells via bacterial type iii secretion systems are important virulence factors in plant-pathogen interactions. type iii secretion systems have been found in rhizobium species that form symbiotic, nitrogen-fixing associations with legumes. one such bacterium, rhizobium sp. ngr234, secretes a number of type iii effectors, including nodulation outer protein l (nopl, formerly y4xl). here, we show that expression of nopl in tobacco (nicotiana taba ... | 2004 | 14966249 |
| antifungal activity of beta-asarone from rhizomes of acorus gramineus. | an antifungal substance was isolated from the extract of acorus gramineus using various chromatographic procedures. the antibiotic was identified as beta-asarone, cis-2,4,5-trimethoxy-1-propenylbenzene, on the basis of the high-resolution ei-mass, nmr, and uv spectral data. beta-asarone completely inhibited mycelial growth of some plant pathogenic fungi, cladosporium cucumerinum,colletotrichum orbiculare, magnaporthe grisea, and pythium ultimum, in a range of 0.5-30 microg/ml. the growth of baci ... | 2004 | 14969530 |
| evidence for hrpxo-dependent expression of type ii secretory proteins in xanthomonas oryzae pv. oryzae. | xanthomonas oryzae pv. oryzae is a causal agent of bacterial leaf blight of rice. recently, an efficient hrp-inducing medium, xom2, was established for this bacterium. in this medium, more than 10 proteins were secreted from the wild-type strain of x. oryzae pv. oryzae. many of these proteins disappeared or decreased in amount in culture on xom2 when incubated with the strain that has a mutation in the hrp regulatory gene. interestingly, the secretory protein profile of a mutant lacking a type i ... | 2004 | 14973015 |
| genomic and genetic analysis of bordetella bacteriophages encoding reverse transcriptase-mediated tropism-switching cassettes. | liu et al. recently described a group of related temperate bacteriophages that infect bordetella subspecies and undergo a unique template-dependent, reverse transcriptase-mediated tropism switching phenomenon (liu et al., science 295: 2091-2094, 2002). tropism switching results from the introduction of single nucleotide substitutions at defined locations in the vr1 (variable region 1) segment of the mtd (major tropism determinant) gene, which determines specificity for receptors on host bacteria ... | 2004 | 14973019 |
| transcriptional profiling of caulobacter crescentus during growth on complex and minimal media. | microarray analysis was used to examine gene expression in the freshwater oligotrophic bacterium caulobacter crescentus during growth on three standard laboratory media, including peptone-yeast extract medium (pye) and minimal salts medium with glucose or xylose as the carbon source. nearly 400 genes (approximately 10% of the genome) varied significantly in expression between at least two of these media. the differentially expressed genes included many encoding transport systems, most notably di ... | 2004 | 14973021 |
| identification and functional characterization of the lactococcus lactis rfb operon, required for dtdp-rhamnose biosynthesis. | dtdp-rhamnose is an important precursor of cell wall polysaccharides and rhamnose-containing exopolysaccharides (eps) in lactococcus lactis. we cloned the rfbacbd operon from l. lactis mg1363, which comprises four genes involved in dtdp-rhamnose biosynthesis. when expressed in escherichia coli, the lactococcal rfbacbd genes could sustain heterologous production of the shigella flexneri o antigen, providing evidence of their functionality. overproduction of the rfbac proteins in l. lactis resulte ... | 2004 | 14973085 |
| evidence for a symbiosis island involved in horizontal acquisition of pederin biosynthetic capabilities by the bacterial symbiont of paederus fuscipes beetles. | pederin belongs to a group of antitumor compounds found in terrestrial beetles and marine sponges. it is used by apparently all members of the rove beetle genera paederus and paederidus as a chemical defense against predators. however, a recent analysis of the putative pederin biosynthesis (ped) gene cluster strongly suggests that pederin is produced by bacterial symbionts. we have sequenced an extended region of the symbiont genome to gain further insight into the biology of this as-yet-uncultu ... | 2004 | 14973122 |
| poplar peroxiredoxin q. a thioredoxin-linked chloroplast antioxidant functional in pathogen defense. | peroxiredoxins are ubiquitous thioredoxin- or glutaredoxin-dependent peroxidases, the function of which is to destroy peroxides. peroxiredoxin q, one of the four plant subtypes, is a homolog of the bacterial bacterioferritin comigratory proteins. we show here that the poplar (populus tremula x populus tremuloides) protein acts as a monomer with an intramolecular disulfide bridge between two conserved cysteines. a wide range of electron donors and substrates was tested. unlike type ii peroxiredox ... | 2004 | 14976238 |
| tetracycline and streptomycin resistance genes, transposons, and plasmids in salmonella enterica isolates from animals in italy. | fifty-eight multidrug-resistant salmonella enterica strains of 20 serotypes, isolated from animal sources in italy, were analyzed for tet(a) and stra-strb, conferring tetracycline and streptomycin resistance, respectively. the stra and strb genes were highly prevalent in salmonella strains of our collection, being detected in 84% of the streptomycin-resistant strains. in many strains, the stra and strb genes were linked to a particular tn5393-derivative transposon characterized by the presence o ... | 2004 | 14982782 |
| identification of a novel pathogen-induced gene encoding a leucine-rich repeat protein expressed in phloem cells of capsicum annuum. | the calrr1 gene, expressed in pepper leaves following infection by xanthomonas campestris pv. vesicatoria, encodes a secreted leucine-rich repeat (lrr) with five tandem repeats of a 24-amino-acid lrr motif. northern blot analyses revealed that calrr1 is not constitutively expressed in pepper plants, but is strongly induced upon the infection by x. campestris pv. vesicatoria, phytophthora capsici, colletotrichum coccodes and colletotrichum gloeosporioides on leaves. calrr1 was not systemically in ... | 2004 | 14984927 |
| interaction between a geminivirus replication protein and the plant sumoylation system. | geminiviruses are small dna viruses that replicate in nuclei of infected plant cells after accumulation of host replication machinery. tomato golden mosaic virus (tgmv) and tomato yellow leaf curl sardinia virus (tylcsv) encode a protein, repac1 (or rep), that is essential for viral replication. rep/repac1 is an oligomeric protein that binds to double-stranded dna, catalyzes cleavage and ligation of single-stranded dna, and is sufficient for host induction. it also interacts with several host pr ... | 2004 | 14990696 |
| the pko2 linear plasmid prophage of klebsiella oxytoca. | temperate bacteriophages with plasmid prophages are uncommon in nature, and of these only phages n15 and py54 are known to have a linear plasmid prophage with closed hairpin telomeres. we report here the complete nucleotide sequence of the 51,601-bp klebsiella oxytoca linear plasmid pko2, and we demonstrate experimentally that it is also a prophage. we call this bacteriophage phiko2. an analysis of the 64 predicted phiko2 genes indicate that it is a fairly close relative of phage n15; they share ... | 2004 | 14996813 |
| in vitro mutagenesis of xanthomonas campestris alpha-amylase gene by partially replacing deoxythymidine triphosphate with 5-bromo-2'-deoxyuridine-5'-triphosphate using a pcr technique. | three mutants of the wild type alpha-amylase gene from xanthomonas campestris pv. campestris 8004 were obtained using a pcr technique in which deoxythymidine triphosphate (dttp) was partially replaced by 5-bromo-2'-deoxyuridine-5'-triphosphate (brdutp), at an optimal dttp:brdutp ratio of 1000:1. of thre three mutants that were obtained and which were sequenced, one mutant with 40 times higher activity than the wild type alpha-amylase gene product was obtained by using primary pcr products as a t ... | 2004 | 15000487 |
| visualization of the phylogenetic content of five genomes using dekapentagonal maps. | the methods presented here summarize phylogenetic relationships of genomes in visually appealing and informative figures. dekapentagonal maps depict phylogenetic information for orthologous genes present in five genomes, and provide a pre-screen for putatively horizontally transferred genes. if the majority of individual gene phylogenies are unresolved, bipartition histograms provide a means of uncovering and analyzing the plurality consensus. analyses of genomes representing five photosynthetic ... | 2004 | 15003123 |
| diversity among xanthomonads pathogenic on pepper and tomato. | xanthomonas campestris pv. vesicatoria, causal agent of bacterial spot of tomato and pepper, had been considered for nearly 70 years to be a relatively homogeneous organism. however, in the past decade this bacterium was determined to be composed of two genetically and phenotypically distinct groups. the two groups, designated a and b, were distinguished based on amylolytic activity, expression of unique protein bands, reaction on differential hosts (tomato races t1 and t2), reaction patterns wi ... | 1998 | 15012492 |
| the leucine-responsive regulatory protein (lrp) gene for characterization of the relationship among xanthomonas species. | characterization of strains of xanthomonas axonopodis pv. citri by using dna fingerprints that were generated from primers for enterobacterial repetitive intergenic consensus (eric) elements led to the discovery of differential sequences for a leucine-responsive regulatory protein (lrp) gene in two subgroups of strains with different host ranges on citrus spp. dna hybridization and pcr-based assays that used different sets of primers were designed to detect the core sequence, as well as to obtai ... | 2004 | 15023955 |
| structural basis for host recognition by the haemophilus influenzae hia autotransporter. | haemophilus influenzae is an important human pathogen that initiates infection by colonizing the upper respiratory tract. the h. influenzae hia autotransporter is an adhesive protein that promotes adherence to respiratory epithelial cells. hia adhesive activity resides in two homologous binding domains, called hiabd1 and hiabd2. these domains interact with the same host cell receptor, but bind with different affinities. in this report, we describe the crystal structure of the high-affinity hiabd ... | 2004 | 15029242 |
| biosynthesis of udp-glca, a key metabolite for capsular polysaccharide synthesis in the pathogenic fungus cryptococcus neoformans. | udp-glucose dehydrogenase catalyses the conversion of udp-glucose into udp-glca, a critical precursor for glycan synthesis across evolution. we have cloned the gene encoding this important enzyme from the opportunistic pathogen cryptococcus neoformans. in this fungus, udp-glca is required for the synthesis of capsule polysaccharides, which in turn are essential for virulence. the gene was expressed in escherichia coli and the 51.3-kda recombinant protein from wild-type and five mutants was purif ... | 2004 | 15030319 |
| the role of a bifunctional catalase-peroxidase kata in protection of agrobacterium tumefaciens from menadione toxicity. | agrobacterium tumefaciens is an aerobic plant pathogenic bacterium that is exposed to reactive oxygen species produced either as by-products of aerobic metabolism or by the defense systems of host plants. the physiological function of the bifunctional catalase-peroxidase (kata) in the protection of a. tumefaciens from reactive oxygen species other than h(2)o(2) was evaluated in the kata mutant (pb102). unexpectedly, pb102 was highly sensitive to the superoxide generator menadione. the expression ... | 2004 | 15033242 |
| a plant natriuretic peptide-like gene in the bacterial pathogen xanthomonas axonopodis may induce hyper-hydration in the plant host: a hypothesis of molecular mimicry. | background: plant natriuretic peptides (pnps) are systemically mobile molecules that regulate homeostasis at nanomolar concentrations. pnps are up-regulated under conditions of osmotic stress and pnp-dependent processes include changes in ion transport and increases of h2o uptake into protoplasts and whole tissue. presentation of the hypothesis: the bacterial citrus pathogen xanthomonas axonopodis pv. citri str. 306 contains a gene encoding a pnp-like protein. we hypothesise that this bacterial ... | 2004 | 15038836 |
| the lspb protein is involved in the secretion of the lspa1 and lspa2 proteins by haemophilus ducreyi. | the lspa1 and lspa2 proteins of haemophilus ducreyi 35000 are two very large macromolecules that can be detected in concentrated culture supernatant fluid. both of these proteins exhibit homology with the n-terminal region of the bordetella pertussis filamentous hemagglutinin (fha), which is involved in secretion of the latter macromolecule. the lspa2 open reading frame is flanked upstream by a gene, lspb, that encodes a predicted protein with homology to the b. pertussis fhac outer membrane pro ... | 2004 | 15039306 |
| 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 |
| comparative genomics of gene-family size in closely related bacteria. | the wealth of genomic data in bacteria is helping microbiologists understand the factors involved in gene innovation. among these, the expansion and reduction of gene families appears to have a fundamental role in this, but the factors influencing gene family size are unclear. | 2004 | 15059260 |
| organization of lin genes and is6100 among different strains of hexachlorocyclohexane-degrading sphingomonas paucimobilis: evidence for horizontal gene transfer. | the organization of lin genes and is6100 was studied in three strains of sphingomonas paucimobilis (b90a, sp+, and ut26) which degraded hexachlorocyclohexane (hch) isomers but which had been isolated at different geographical locations. dna-dna hybridization data revealed that most of the lin genes in these strains were associated with is6100, an insertion sequence classified in the is6 family and initially found in mycobacterium fortuitum. eleven, six, and five copies of is6100 were detected in ... | 2004 | 15060023 |
| characterization of the cis-acting regulatory element controlling hrpb-mediated activation of the type iii secretion system and effector genes in ralstonia solanacearum. | the ability of ralstonia solanacearum to cause disease on plants depends on its type iii secretion system (ttss) encoded by hrp genes. the expression of hrp genes and known ttss substrates is coordinately regulated by hrpb, a member of the arac family of transcriptional regulators. two hrpb-regulated promoters (hrpy and popabc) were characterized by deletion analysis, and the hrpb-dependent activation of these promoters was found to be conferred by a 25-nucleotide dna element, the hrp(ii) box (t ... | 2004 | 15060033 |
| fundamental structural units of the escherichia coli nucleoid revealed by atomic force microscopy. | a small container of several to a few hundred microm3 (i.e. bacterial cells and eukaryotic nuclei) contains extremely long genomic dna (i.e. mm and m long, respectively) in a highly organized fashion. to understand how such genomic architecture could be achieved, escherichia coli nucleoids were subjected to structural analyses under atomic force microscopy, and found to change their structure dynamically during cell growth, i.e. the nucleoid structure in the stationary phase was more tightly com ... | 2004 | 15060178 |
| the oligopeptide permease (opp) of the plant pathogen xanthomonas axonopodis pv. citri. | the oligopeptide permease (opp), a protein-dependent abc transporter, has been found in the genome of xanthomonas axonopodis pv. citri ( xac), but not in xanthomonas campestris pv. campestris ( xcc). sequence analysis indicated that 4 opp genes ( oppa, oppb, oppc, oppd/f), located in a 33.8-kbp dna fragment present only in the xac genome, are arranged in an operon-like structure and share highest sequence similarities with streptomyces roseofulvus orthologs. nonetheless, analyses of the gc conte ... | 2004 | 15060731 |
| g-primer: greedy algorithm for selecting minimal primer set. | g-primer, a web-based primer design program, has been developed to compute a minimal primer set specifically annealed to all the open reading frames in a given microbial genome. this program has been successfully used in the microarray experiment for analyzing the expression of genes in the xanthomonas campestris genome. availability: it is available at http://mammoth.bii.a-star.edu.sg/gprimer/. its source code is available upon request. | 2004 | 15073009 |
| divergence and redundancy of 16s rrna sequences in genomes with multiple rrn operons. | the level of sequence heterogeneity among rrn operons within genomes determines the accuracy of diversity estimation by 16s rrna-based methods. furthermore, the occurrence of widespread horizontal gene transfer (hgt) between distantly related rrn operons casts doubt on reconstructions of phylogenetic relationships. for this study, patterns of distribution of rrn copy numbers, interoperonic divergence, and redundancy of 16s rrna sequences were evaluated. bacterial genomes display up to 15 operons ... | 2004 | 15090503 |
| conserved glycines in the c terminus of minc proteins are implicated in their functionality as cell division inhibitors. | alignment of 36 minc sequences revealed four completely conserved c-terminal glycines. as minc inhibits cytokinesis in neisseria gonorrhoeae and escherichia coli, the functional importance of these glycines in n. gonorrhoeae minc (minc(ng)) and e. coli minc (minc(ec)) was investigated through amino acid substitution by using site-directed mutagenesis. each mutant was evaluated for its ability to arrest cell division and to interact with itself and mind. in contrast to overexpression of wild-type ... | 2004 | 15090526 |
| capsicum annuum tobacco mosaic virus-induced clone 1 expression perturbation alters the plant's response to ethylene and interferes with the redox homeostasis. | capsicum annuum tobacco mosaic virus (tmv)-induced clone 1 (catin1) gene was expressed early during incompatible interaction of hot pepper (caspsicum annuum) plants with tmv and xanthomonas campestris. rna-blot analysis showed that catin1 gene was expressed only in roots in untreated plants and induced mainly in leaf in response to ethylene, nacl, and methyl viologen but not by salicylic acid and methyl jasmonate. the ethylene dependence of catin1 induction upon tmv inoculation was demonstrated ... | 2004 | 15107506 |
| functional dissection of the xpsn (gspc) protein of the xanthomonas campestris pv. campestris type ii secretion machinery. | type ii secretion machinery is composed of 12 to 15 proteins for translocating extracellular proteins across the outer membrane. xpsl, xpsm, and xpsn are components of such machinery in the plant pathogen xanthomonas campestris pv. campestris. all are bitopic cytoplasmic-membrane proteins, each with a large c-terminal periplasmic domain. they have been demonstrated to form a dissociable ternary complex. by analyzing the c-terminally truncated xpsn and phoa fusions, we discovered that truncation ... | 2004 | 15126454 |
| evaluation of xanthan and highly substituted galactomannan from m. scabrella as a sustained release matrix. | a highly substituted galactomannan (g) from mimosa scabrella bentham (man:gal 1.1:1), isolated from the seeds of a brazilian leguminous tree and xanthan (x), an exopolysaccharide secreted by xanthomonas campestris (keltrol), were evaluated as a hydrophilic matrix system (xg) for controlled release (cr) of diclofenac sodium (ds) in tablets and capsules. the performance of xg (2:1) matrices containing 50 mg (a) or 100 mg (b) of ds was compared with a commercial cr product of ds. the drug release s ... | 2004 | 15129986 |
| the role of the jasmonate response in plant susceptibility to diverse pathogens with a range of lifestyles. | plants defend themselves against attack from insects and pathogens with various resistance strategies. the jasmonate and salicylate signaling pathways are two induced responses that protect plants against these attackers. knowledge of the range of organisms that are affected by each response is important for understanding how plants coordinate their defenses against multiple attackers and the generality of effect of different resistance mechanisms. the jasmonate response is known to protect plan ... | 2004 | 15133157 |
| bacterial signal transduction network in a genomic perspective. | bacterial signalling network includes an array of numerous interacting components that monitor environmental and intracellular parameters and effect cellular response to changes in these parameters. the complexity of bacterial signalling systems makes comparative genome analysis a particularly valuable tool for their studies. comparative studies revealed certain general trends in the organization of diverse signalling systems. these include (i) modular structure of signalling proteins; (ii) comm ... | 2004 | 15142243 |
| the pseudomonas syringae hopptov protein is secreted in culture and translocated into plant cells via the type iii protein secretion system in a manner dependent on the shcv type iii chaperone. | the bacterial plant pathogen pseudomonas syringae depends on a type iii protein secretion system and the effector proteins that it translocates into plant cells to cause disease and to elicit the defense-associated hypersensitive response on resistant plants. the availability of the p. syringae pv. tomato dc3000 genome sequence has resulted in the identification of many novel effectors. we identified the hopptov effector gene on the basis of its location next to a candidate type iii chaperone (t ... | 2004 | 15150250 |
| molecular genetic analyses of potential beta-galactosidase genes in xanthomonas campestris. | xanthomonas campestris pv. campestris, which displays no significant beta-1,4-d-galactopyranosidase activity, has three annotated beta-galactosidase genes in the sequenced genome, designated gala, galb and galc herein. gala and galb are similar to glycosyl hydrolase (gh) family 2 enzymes, including escherichia coli lacz. gala and galb cannot express detectable activity even after being cloned in-frame and driven by the vector's promoter. galc is a gh35 enzyme homologous to the xanthomonas axonop ... | 2003 | 15153767 |
| biofilm formation and dispersal in xanthomonas campestris. | xanthomonas campestris pathovar campestris is the causal agent of black rot disease of cruciferous plants. a cell-cell signalling system encoded by genes within the rpf cluster is required for the full virulence of this plant pathogen. this system has recently been implicated in regulation of the formation and dispersal of xanthomonas biofilms. | 2004 | 15158198 |
| bacterial genomes as new gene homes: the genealogy of orfans in e. coli. | differences in gene repertoire among bacterial genomes are usually ascribed to gene loss or to lateral gene transfer from unrelated cellular organisms. however, most bacteria contain large numbers of orfans, that is, annotated genes that are restricted to a particular genome and that possess no known homologs. the uniqueness of orfans within a genome has precluded the use of a comparative approach to examine their function and evolution. however, by identifying sequences unique to monophyletic g ... | 2004 | 15173110 |
| identification of mdod, an mdog paralog which encodes a twin-arginine-dependent periplasmic protein that controls osmoregulated periplasmic glucan backbone structures. | osmoregulated periplasmic glucans (opgs) of escherichia coli are anionic and highly branched oligosaccharides that accumulate in the periplasmic space in response to low osmolarity of the medium. the glucan length, ranging from 5 to 12 glucose residues, is under strict control. two genes that form an operon, mdogh, govern glucose backbone synthesis. the new gene mdod, which appears to be a paralog of mdog, was characterized in this study. cassette inactivation of mdod resulted in production of o ... | 2004 | 15175282 |
| in vivo immobilization of fusion proteins on bioplastics by the novel tag biof. | a new protein immobilization and purification system has been developed based on the use of polyhydroxyalkanoates (phas, or bioplastics), which are biodegradable polymers accumulated as reserve granules in the cytoplasm of certain bacteria. the n-terminal domain of the phaf phasin (a pha-granule-associated protein) from pseudomonas putida gpo1 was used as a polypeptide tag (biof) to anchor fusion proteins to phas. this tag provides a novel way to immobilize proteins in vivo by using bioplastics ... | 2004 | 15184113 |
| purification, characterization, and sequencing of an extracellular cold-active aminopeptidase produced by marine psychrophile colwellia psychrerythraea strain 34h. | the limited database on cold-active extracellular proteases from marine bacteria was expanded by successful purification and initial biochemical and structural characterization of a family m1 aminopeptidase (designated colap) produced by the marine psychrophile colwellia psychrerythraea strain 34h. the 71-kda enzyme displayed a low optimum temperature (19 degrees c) and narrow ph range (ph 6 to 8.5) for activity and greater thermolability than other extracellular proteases. sequencing of the gen ... | 2004 | 15184127 |
| characterization of the xanthomonas avrxv4 effector, a sumo protease translocated into plant cells. | homologs of the yersinia virulence factor yopj are found in both animal and plant bacterial pathogens, as well as in plant symbionts. the conservation of this effector family indicates that several pathogens may use yopj-like proteins to regulate bacteria-host interactions during infection. yopj and yopj-like proteins share structural homology with cysteine proteases and are hypothesized to functionally mimic small ubiquitin-like modifier (sumo) proteases in eukaryotic cells. strains of the phyt ... | 2004 | 15195946 |
| variation in the effectors of the type iii secretion system among photorhabdus species as revealed by genomic analysis. | entomopathogenic bacteria of the genus photorhabdus harbor a type iii secretion system. this system was probably acquired prior to the separation of the species within this genus. furthermore, the core components of the secretion machinery are highly conserved but the predicted effectors differ between photorhabdus luminescens and p. asymbiotica, two highly related species with different hosts. | 2004 | 15205440 |
| endophytic bacterial communities of field-grown potato plants and their plant-growth-promoting and antagonistic abilities. | to study the effect of plant growth on potato-associated bacteria, the composition and properties of bacteria colonizing the endosphere of field-grown potato were analyzed by a multiphasic approach. the occurrence and diversity of potato-associated bacteria were monitored by a cultivation-independent approach, using terminal restriction fragment length polymorphism analysis of 16s rdna. the patterns obtained revealed a high heterogeneity of community composition and suggested the existence of pl ... | 2004 | 15213748 |
| comparative genomics of the methionine metabolism in gram-positive bacteria: a variety of regulatory systems. | regulation of the methionine biosynthesis and transport genes in bacteria is rather diverse and involves two rna-level regulatory systems and at least three dna-level systems. in particular, the methionine metabolism in gram-positive bacteria was known to be controlled by the s-box and t-box mechanisms, both acting on the level of premature termination of transcription. using comparative analysis of genes, operons and regulatory elements, we described the methionine metabolic pathway and the met ... | 2004 | 15215334 |
| bomp: a program to predict integral beta-barrel outer membrane proteins encoded within genomes of gram-negative bacteria. | this work describes the development of a program that predicts whether or not a polypeptide sequence from a gram-negative bacterium is an integral beta-barrel outer membrane protein. the program, called the beta-barrel outer membrane protein predictor (bomp), is based on two separate components to recognize integral beta-barrel proteins. the first component is a c-terminal pattern typical of many integral beta-barrel proteins. the second component calculates an integral beta-barrel score of the ... | 2004 | 15215418 |
| two genetic loci produce distinct carbohydrate-rich structural components of the pseudomonas aeruginosa biofilm matrix. | pseudomonas aeruginosa forms biofilms, which are cellular aggregates encased in an extracellular matrix. molecular genetics studies of three common autoaggregative phenotypes, namely wrinkled colonies, pellicles, and solid-surface-associated biofilms, led to the identification of two loci, pel and psl, that are involved in the production of carbohydrate-rich components of the biofilm matrix. the pel gene cluster is involved in the production of a glucose-rich matrix material in p. aeruginosa str ... | 2004 | 15231777 |
| helicobacter pylori flgr is an enhancer-independent activator of sigma54-rna polymerase holoenzyme. | helicobacter pylori flgr activates transcription with sigma54-rna polymerase holoenzyme (sigma54-holoenzyme) from at least five flagellar operons. activators of sigma54-holoenzyme generally bind enhancer sequences located >70 bp upstream of the promoter and contact sigma54-holoenzyme bound at the promoter through dna looping to activate transcription. h. pylori flgr lacks the carboxy-terminal dna-binding domain present in most sigma54-dependent activators. as little as 42 bp of dna upstream of t ... | 2004 | 15231786 |
| fur is involved in manganese-dependent regulation of mnta (sita) expression in sinorhizobium meliloti. | fur is a transcriptional regulator involved in iron-dependent control of gene expression in many bacteria. in this work we analyzed the phenotype of a fur mutant in sinorhizobium meliloti, an alpha-proteobacterium that fixes n(2) in association with host plants. we demonstrated that some functions involved in high-affinity iron transport, siderophore production, and iron-regulated outer membrane protein expression respond to iron in a fur-independent manner. however, manganese-dependent expressi ... | 2004 | 15240318 |
| basal defenses induced in pepper by lipopolysaccharides are suppressed by xanthomonas campestris pv. vesicatoria. | the nonpathogenic hrcc mutant of xanthomonas campestris pv. vesicatoria 85-10::hrpa22 multiplied in pepper leaves if it was mixed with pathogenic strains of x. campestris pv. vesicatoria. reactions to the mutant alone included localized deposition of phenolics and callose in papillae, and alterations to the plant cell wall leading to increased electron density. electron microscopy showed that the localized responses were suppressed in the presence of wild-type bacteria but other wall changes occ ... | 2004 | 15242175 |
| molecular cloning and characterization of bifidobacterium bifidum 1,2-alpha-l-fucosidase (afca), a novel inverting glycosidase (glycoside hydrolase family 95). | a genomic library of bifidobacterium bifidum constructed in escherichia coli was screened for the ability to hydrolyze the alpha-(1-->2) linkage of 2'-fucosyllactose, and a gene encoding 1,2-alpha-l-fucosidase (afca) was isolated. the afca gene was found to comprise 1,959 amino acid residues with a predicted molecular mass of 205 kda and containing a signal peptide and a membrane anchor at the n and c termini, respectively. a domain responsible for fucosidase activity (the fuc domain; amino acid ... | 2004 | 15262925 |
| a type ii protein secretory pathway required for levansucrase secretion by gluconacetobacter diazotrophicus. | the endophytic diazotroph gluconacetobacter diazotrophicus secretes a constitutively expressed levansucrase (lsda, ec 2.4.1.10) to utilize plant sucrose. lsda, unlike other extracellular levansucrases from gram-negative bacteria, is transported to the periplasm by a signal-peptide-dependent pathway. we identified an unusually organized gene cluster encoding at least the components lsdg, -o, -e, -f, -h, -i, -j, -l, -m, -n, and -d of a type ii secretory system required for lsda translocation acros ... | 2004 | 15262940 |
| nucleotide sequence and evolution of the five-plasmid complement of the phytopathogen pseudomonas syringae pv. maculicola es4326. | plasmids are transmissible, extrachromosomal genetic elements that are often responsible for environmental or host-specific adaptations. in order to identify the forces driving the evolution of these important molecules, we determined the complete nucleotide sequence of the five-plasmid complement of the radish and arabidopsis pathogen pseudomonas syringae pv. maculicola es4326 and conducted an intraspecific comparative genomic analysis. to date, this is the most complex fully sequenced plasmid ... | 2004 | 15262947 |
| genome sequence of the enterobacterial phytopathogen erwinia carotovora subsp. atroseptica and characterization of virulence factors. | the bacterial family enterobacteriaceae is notable for its well studied human pathogens, including salmonella, yersinia, shigella, and escherichia spp. however, it also contains several plant pathogens. we report the genome sequence of a plant pathogenic enterobacterium, erwinia carotovora subsp. atroseptica (eca) strain scri1043, the causative agent of soft rot and blackleg potato diseases. approximately 33% of eca genes are not shared with sequenced enterobacterial human pathogens, including s ... | 2004 | 15263089 |
| vascular associated death1, a novel gram domain-containing protein, is a regulator of cell death and defense responses in vascular tissues. | the hypersensitive response (hr) is a programmed cell death that is commonly associated with plant disease resistance. a novel lesion mimic mutant, vad1 (for vascular associated death1), that exhibits light conditional appearance of propagative hr-like lesions along the vascular system was identified. lesion formation is associated with expression of defense genes, production of high levels of salicylic acid (sa), and increased resistance to virulent and avirulent strains of pseudomonas syringae ... | 2004 | 15269331 |
| evidence for a new sub-class of methionine sulfoxide reductases b with an alternative thioredoxin recognition signature. | methionine sulfoxide reductases catalyze the reduction of protein-bound methionine sulfoxide back to methionine via a thioredoxin-recycling process. two classes of methionine sulfoxide reductases, called msra and msrb, exist that display opposite stereoselectivities toward the sulfoxide function. although they are structurally unrelated, they share a similar chemical mechanism that includes three steps with 1) formation of a sulfenic acid intermediate with a concomitant release of 1 mol of methi ... | 2004 | 15280355 |
| cloning and partial characterization of zwittermicin a resistance gene cluster from bacillus thuringiensis subsp. kurstaki strain hd1. | the study seeks to shed light on the aminopolyol, broad-spectrum antibiotic zwittermicin a gene cluster of bacillus thuringiensis subsp. kurstaki hd1 and to identify any new uncharacterized genes with an eventual goal to establish a better understanding of the resistance gene cluster. | 2004 | 15281929 |
| polyhydroxyalkanoate (pha) accumulation in sulfate-reducing bacteria and identification of a class iii pha synthase (phaec) in desulfococcus multivorans. | seven strains of sulfate-reducing bacteria (srb) were tested for the accumulation of polyhydroxyalkanoates (phas). during growth with benzoate desulfonema magnum accumulated large amounts of poly(3-hydroxybutyrate) [poly(3hb)]. desulfosarcina variabilis (during growth with benzoate), desulfobotulus sapovorans (during growth with caproate), and desulfobacterium autotrophicum (during growth with caproate) accumulated poly(3hb) that accounted for 20 to 43% of cell dry matter. desulfobotulus sapovor ... | 2004 | 15294771 |
| bactericidal activity of glycinecin a, a bacteriocin derived from xanthomonas campestris pv. glycines, on phytopathogenic xanthomonas campestris pv. vesicatoria cells. | the ability of glycinecin a, a bacteriocin derived from xanthomonas campestris pv. glycines 8ra, to kill closely related bacteria has been demonstrated previously by our group. in the present study, we aimed at determining the glycinecin a-induced cause of death. treatment with glycinecin a caused slow dissipation of membrane potential and rapid depletion of the ph gradient. glycinecin a treatment also induced leakage of potassium ions from x. campestris pv. vesicatoria yk93-4 cells and killed s ... | 2004 | 15294776 |
| xanthan gum production from cassava bagasse hydrolysate with xanthomonas campestris using alternative sources of nitrogen. | cassava bagasse was hydrolyzed using hcl and the hydrolysate was used for the production of xanthan gum using a bacterial culture of xanthomonas campestris. cassava bagasse hydrolysate with an initial concentration of approx 20 g of glucose/l proved to be the best substrate concentration for xanthan gum production. among the organic and inorganic nitrogen sources tested to supplement the medium-urea, yeast extract, peptone, potassium nitrate, and ammonium sulfate-potassium nitrate was most suita ... | 2004 | 15304758 |
| xanthan gum production by xanthomonas campestris w.t. fermentation from chestnut extract. | xanthomonas campestris w.t. was used for production of xanthan gum in fermentations with chestnut flour for the first time. fermentations were carried out with either chestnut flour or its soluble sugars (33.5%) and starch (53.6%), respectively, at 28 degrees c and 200 rpm at initial ph 7.0 in flasks. the effect of agitation rate (at 200, 400, and 600 rpm) on xanthan gum production was also studied in a 2-l batch reactor. it was found that xanthan production reaches a maximum value of 3.3 g/100 ... | 1999 | 15304770 |
| cloning and expression of afpa, a gene encoding an antifreeze protein from the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2. | the arctic plant growth-promoting rhizobacterium pseudomonas putida gr12-2 secretes an antifreeze protein (afp) that promotes survival at subzero temperatures. the afp is unusual in that it also exhibits a low level of ice nucleation activity. a dna fragment with an open reading frame encoding 473 amino acids was cloned by pcr and inverse pcr using primers designed from partial amino acid sequences of the isolated afp. the predicted gene product, afpa, had a molecular mass of 47.3 kda, a pi of 3 ... | 2004 | 15317770 |
| different patterns of evolution for duplicated dna repair genes in bacteria of the xanthomonadales group. | dna repair genes encode proteins that protect organisms against genetic damage generated by environmental agents and by-products of cell metabolism. the importance of these genes in life maintenance is supported by their high conservation, and the presence of duplications of such genes may be easily traced, especially in prokaryotic genomes. | 2004 | 15333143 |
| in search of rnase p rna from microbial genomes. | a simple procedure has been developed to quickly retrieve and validate the dna sequence encoding the rna subunit of ribonuclease p (rnase p rna) from microbial genomes. rnase p rna sequences were identified from 94% of bacterial and archaeal complete genomes where previously no rnase p rna was annotated. a sequence was found in camelpox virus, highly conserved in all orthopoxviruses (including smallpox virus), which could fold into a putative rnase p rna in terms of conserved primary features an ... | 2004 | 15337843 |
| in vivo phosphorylation of partner switching regulators correlates with stress transmission in the environmental signaling pathway of bacillus subtilis. | exposure of bacteria to diverse growth-limiting stresses induces the synthesis of a common set of proteins which provide broad protection against future, potentially lethal stresses. among bacillus subtilis and its relatives, this general stress response is controlled by the sigmab transcription factor. signals of environmental and energy stress activate sigmab through a multicomponent network that functions via a partner switching mechanism, in which protein-protein interactions are governed by ... | 2004 | 15342582 |
| mutational analysis of xanthomonas harpin hpag identifies a key functional region that elicits the hypersensitive response in nonhost plants. | hpag is a type iii-secreted elicitor protein of xanthomonas axonopodis pv. glycines. we have determined the critical amino acid residues important for hypersensitive response (hr) elicitation by random and site-directed mutagenesis of hpag and its homolog xopa. a plasmid clone carrying hpag was mutagenized by site-directed mutagenesis, hydroxylamine mutagenesis, and error-prone pcr. a total of 52 mutants were obtained, including 51 single missense mutants and 1 double missense mutant. the hr eli ... | 2004 | 15342594 |
| the pen1 syntaxin defines a novel cellular compartment upon fungal attack and is required for the timely assembly of papillae. | attack by the host powdery mildew erysiphe cichoracearum usually results in successful penetration and rapid proliferation of the fungus on arabidopsis. by contrast, the nonhost barley powdery mildew blumeria graminis f. sp. hordei (bgh) typically fails to penetrate arabidopsis epidermal cells. in both instances the plant secretes cell wall appositions or papillae beneath the penetration peg of the fungus. genetic screens for mutations that result in increased penetration of bgh on arabidopsis h ... | 2004 | 15342780 |
| comparison of atpase-encoding type iii secretion system hrcn genes in biocontrol fluorescent pseudomonads and in phytopathogenic proteobacteria. | type iii protein secretion systems play a key role in the virulence of many pathogenic proteobacteria, but they also occur in nonpathogenic, plant-associated bacteria. certain type iii protein secretion genes (e.g., hrcc) have been found in pseudomonas sp. strain sbw25 (and other biocontrol pseudomonads), but other type iii protein secretion genes, such as the atpase-encoding gene hrcn, have not been found. using both colony hybridization and a pcr approach, we show here that hrcn is nevertheles ... | 2004 | 15345390 |
| the pepper transcription factor capf1 confers pathogen and freezing tolerance in arabidopsis. | an erf/ap2-type transcription factor (capf1) was isolated by differential-display reverse transcription-pcr, following inoculation of the soybean pustule pathogen xanthomonas axonopodis pv glycines 8ra, which induces hypersensitive response in pepper (capsicum annuum) leaves. capf1 mrna was induced under conditions of biotic and abiotic stress. higher levels of capf1 transcripts were observed in disease-resistant tissue compared with susceptible tissue. capf1 expression was additionally induced ... | 2004 | 15347795 |
| complete genomic sequence of bacteriophage b3, a mu-like phage of pseudomonas aeruginosa. | bacteriophage b3 is a transposable phage of pseudomonas aeruginosa. in this report, we present the complete dna sequence and annotation of the b3 genome. dna sequence analysis revealed that the b3 genome is 38,439 bp long with a g+c content of 63.3%. the genome contains 59 proposed open reading frames (orfs) organized into at least three operons. of these orfs, the predicted proteins from 41 orfs (68%) display significant similarity to other phage or bacterial proteins. many of the predicted b3 ... | 2004 | 15375138 |
| an energy taxis transducer promotes root colonization by azospirillum brasilense. | motility responses triggered by changes in the electron transport system are collectively known as energy taxis. in azospirillum brasilense, energy taxis was shown to be the principal form of locomotor control. in the present study, we have identified a novel chemoreceptor-like protein, named tlp1, which serves as an energy taxis transducer. the tlp1 protein is predicted to have an n-terminal periplasmic region and a cytoplasmic c-terminal signaling module homologous to those of other chemorecep ... | 2004 | 15375141 |
| genomic plasticity of the causative agent of melioidosis, burkholderia pseudomallei. | burkholderia pseudomallei is a recognized biothreat agent and the causative agent of melioidosis. this gram-negative bacterium exists as a soil saprophyte in melioidosis-endemic areas of the world and accounts for 20% of community-acquired septicaemias in northeastern thailand where half of those affected die. here we report the complete genome of b. pseudomallei, which is composed of two chromosomes of 4.07 megabase pairs and 3.17 megabase pairs, showing significant functional partitioning of g ... | 2004 | 15377794 |
| the secretome of the plant pathogenic bacterium erwinia chrysanthemi. | erwinia chrysanthemi causes soft-rot diseases of many plants by secreting a battery of enzymes which degrade the plant cell walls. we initiated a proteomic analysis to create a reference map of the e. chrysanthemi secretome. extracellular proteins were isolated from e. chrysanthemi culture supernatants and resolved by two-dimensional electrophoresis. by analysis of mutants, western blotting, and matrix-assisted laser desorption/ionization-time of flight (maldi-tof) 55 spots representing 25 uniqu ... | 2004 | 15378709 |
| effect of dimer dissociation on activity and thermostability of the alpha-glucuronidase from geobacillus stearothermophilus: dissecting the different oligomeric forms of family 67 glycoside hydrolases. | the oligomeric organization of enzymes plays an important role in many biological processes, such as allosteric regulation, conformational stability and thermal stability. alpha-glucuronidases are family 67 glycosidases that cleave the alpha-1,2-glycosidic bond between 4-o-methyl-d-glucuronic acid and xylose units as part of an array of hemicellulose-hydrolyzing enzymes. currently, two crystal structures of alpha-glucuronidases are available, those from geobacillus stearothermophilus (agua) and ... | 2004 | 15466046 |
| characterization of plasmid por1 from ornithobacterium rhinotracheale and construction of a shuttle plasmid. | the bacterium ornithobacterium rhinotracheale has been recognized as an emerging pathogen in poultry since about 10 years ago. knowledge of this bacterium and its mechanisms of virulence is still very limited. here we report the development of a transformation system that enables genetic modification of o. rhinotracheale. the system is based on a cryptic plasmid, por1, that was derived from an o. rhinotracheale strain of serotype k. sequencing indicated that the plasmid consisted of 14,787 nucle ... | 2004 | 15466524 |
| transcriptional analysis of biofilm formation processes in the anaerobic, hyperthermophilic bacterium thermotoga maritima. | thermotoga maritima, a fermentative, anaerobic, hyperthermophilic bacterium, was found to attach to bioreactor glass walls, nylon mesh, and polycarbonate filters during chemostat cultivation on maltose-based media at 80 degrees c. a whole-genome cdna microarray was used to examine differential expression patterns between biofilm and planktonic populations. mixed-model statistical analysis revealed differential expression (twofold or more) of 114 open reading frames in sessile cells (6% of the ge ... | 2004 | 15466556 |
| variation suggestive of horizontal gene transfer at a lipopolysaccharide (lps) biosynthetic locus in xanthomonas oryzae pv. oryzae, the bacterial leaf blight pathogen of rice. | in animal pathogenic bacteria, horizontal gene transfer events (hgt) have been frequently observed in genomic regions that encode functions involved in biosynthesis of the outer membrane located lipopolysaccharide (lps). as a result, different strains of the same pathogen can have substantially different lps biosynthetic gene clusters. since lps is highly antigenic, the variation at lps loci is attributed to be of advantage in evading the host immune system. although lps has been suggested as a ... | 2004 | 15473911 |
| a phylogenetic analysis of wadi el natrun soda lake cellulase enrichment cultures and identification of cellulase genes from these cultures. | samples of sediments and surrounding soda soils (ss) from the extremely saline and alkaline lakes of the wadi el natrun in the libyan desert, egypt, were obtained in october 2000. anaerobic enrichment cultures were grown from these samples, dna isolated, and the bacterial diversity assessed by 16s rrna gene clone analysis. clones derived from lake sediments (ls) most closely matched clostridium spp., natronoincola histidinovorans, halocella cellulolytica, bacillus spp., and the cytophaga-flexiba ... | 2004 | 15480866 |
| hpab from xanthomonas campestris pv. vesicatoria acts as an exit control protein in type iii-dependent protein secretion. | the hrp (hypersensitive response and pathogenicity) gene cluster of the plant pathogenic bacterium xanthomonas campestris pv. vesicatoria encodes a type iii secretion (tts) system, which injects bacterial effector proteins into the plant cell. here, we characterized hpab (hpa, hrp-associated), which encodes a pathogenicity factor with typical features of a tts chaperone. we show that hpab is important for the efficient secretion of at least five effector proteins but is dispensable for the secre ... | 2004 | 15491365 |
| innate immunity in arabidopsis thaliana: lipopolysaccharides activate nitric oxide synthase (nos) and induce defense genes. | lipopolysaccharides (lps) are cell-surface components of gram-negative bacteria and are microbe-/pathogen-associated molecular patterns in animal pathosystems. as for plants, the molecular mechanisms of signal transduction in response to lps are not known. here, we show that arabidopsis thaliana reacts to lps with a rapid burst of no, a hallmark of innate immunity in animals. fifteen lps preparations (among them burkholderia cepacia, pseudomonas aeruginosa, and erwinia carotovora) as well as lip ... | 2004 | 15498873 |
| diversity and antagonistic potential of bacteria associated with bryophytes from nutrient-poor habitats of the baltic sea coast. | very little is known about the interaction of bryophytes with bacteria. therefore, we analyzed bacteria associated with three bryophyte species, tortula ruralis, aulacomnium palustre, and sphagnum rubellum, which represent typical moss species of three nutrient-poor plant communities at the southern baltic sea coast in germany. by use of two cultivation-independent techniques, denaturing gradient gel electrophoresis and single-strand conformation polymorphism analysis of the 16s ribosomal dna, a ... | 2004 | 15528520 |
| characterization of bacterial community diversity in cystic fibrosis lung infections by use of 16s ribosomal dna terminal restriction fragment length polymorphism profiling. | progressive loss of lung function resulting from the inflammatory response to bacterial colonization is the leading cause of mortality in cystic fibrosis (cf) patients. a greater understanding of these bacterial infections is needed to improve lung disease management. as culture-based diagnoses are associated with fundamental drawbacks, we used terminal restriction fragment (t-rf) length polymorphism profiling and 16s rrna clone data to characterize, without prior cultivation, the bacterial comm ... | 2004 | 15528712 |
| a genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land. | the timescale of prokaryote evolution has been difficult to reconstruct because of a limited fossil record and complexities associated with molecular clocks and deep divergences. however, the relatively large number of genome sequences currently available has provided a better opportunity to control for potential biases such as horizontal gene transfer and rate differences among lineages. we assembled a data set of sequences from 32 proteins (approximately 7600 amino acids) common to 72 species ... | 2004 | 15535883 |
| the bag or the spindle: the cell factory at the time of systems' biology. | genome programs changed our view of bacteria as cell factories, by making them amenable to systematic rational improvement. as a first step, isolated genes (including those of the metagenome), or small gene clusters are improved and expressed in a variety of hosts. new techniques derived from functional genomics (transcriptome, proteome and metabolome studies) now allow users to shift from this single-gene approach to a more integrated view of the cell, where it is more and more considered as a ... | 2004 | 15537427 |
| a genetic screen to isolate type iii effectors translocated into pepper cells during xanthomonas infection. | the bacterial pathogen xanthomonas campestris pv. vesicatoria (xcv) uses a type iii secretion system (ttss) to translocate effector proteins into host plant cells. the ttss is required for xcv colonization, yet the identity of many proteins translocated through this apparatus is not known. we used a genetic screen to functionally identify xcv ttss effectors. a transposon 5 (tn5)-based transposon construct including the coding sequence for the xcv avrbs2 effector devoid of its ttss signal was ran ... | 2004 | 15545602 |
| exploiting thiol modifications. | | 2004 | 15547642 |
| identification and expression profiling of tomato genes differentially regulated during a resistance response to xanthomonas campestris pv. vesicatoria. | the gram-negative bacterium xanthomonas campestris pv. vesicatoria is the causal agent of spot disease in tomato and pepper. plants of the tomato line hawaii 7981 are resistant to race t3 of x. campestris pv. vesicatoria expressing the type iii effector protein avrxv3 and develop a typical hypersensitive response upon bacterial challenge. a combination of suppression subtractive hybridization and microarray analysis identified a large set of cdnas that are induced or repressed during the resista ... | 2004 | 15553246 |
| modulation of swarming and virulence by fatty acids through the rsba protein in proteus mirabilis. | after sensing external signals, proteus mirabilis undergoes a multicellular behavior called swarming which is coordinately regulated with the expression of virulence factors. here we report that exogenously added fatty acids could act as signals to regulate swarming in p. mirabilis. specifically, while oleic acid enhanced swarming, some saturated fatty acids, such as lauric acid, myristic acid, palmitic acid, and stearic acid, inhibited swarming. we also found that expression of hemolysin, which ... | 2004 | 15557604 |
| ornithine decarboxylase gene (caodc1) is specifically induced during tmv-mediated but salicylate-independent resistant response in hot pepper. | a gene encoding putative ornithine decarboxylase (odc) has been isolated by differential screening of a cdna library from the resistant hot pepper (capsicum annuum l.) inoculated with avirulent tobacco mosaic virus (tmv) pathotype p0. in hot pepper plants, transcripts of the caodc1 (c. annuum odc1) gene started to accumulate at 24 h post-inoculation of tmv-p0 and the signal was spread systemically. the transcript level of caodc1 was increased rapidly in a hot pepper resistant to xanthomonas camp ... | 2004 | 15564537 |
| characterisation of a secondary alcohol dehydrogenase from xanthomonas campestris dsm 3586. | the chromosomal locus np_636946 of xanthomonas campestris dsm 3586 (atcc 33913) which was earlier presumed to encode a quinoprotein glucose dehydrogenase has been cloned, expressed in escherichia coli and the recombinant enzyme has been characterised. it was found to have no glucose dehydrogenase activity but to be active on many different polyols and diols, aliphatic alcohols, certain aldonic acids and amino-sugars. the product of d: -gluconic acid oxidation was 5-keto-d: -gluconic acid. the en ... | 2005 | 15565334 |
| characterization of a novel amylolytic enzyme encoded by a gene from a soil-derived metagenomic library. | it has been estimated that less than 1% of the microorganisms in nature can be cultivated by conventional techniques. thus, the classical approach of isolating enzymes from pure cultures allows the analysis of only a subset of the total naturally occurring microbiota in environmental samples enriched in microorganisms. to isolate useful microbial enzymes from uncultured soil microorganisms, a metagenome was isolated from soil samples, and a metagenomic library was constructed by using the puc19 ... | 2004 | 15574921 |
| complete nucleotide sequence of the conjugative tetracycline resistance plasmid pfbaot6, a member of a group of incu plasmids with global ubiquity. | this study presents the first complete sequence of an incu plasmid, pfbaot6. this plasmid was originally isolated from a strain of aeromonas caviae from hospital effluent (westmorland general hospital, kendal, united kingdom) in september 1997 (g. rhodes, g. huys, j. swings, p. mcgann, m. hiney, p. smith, and r. w. pickup, appl. environ. microbiol. 66:3883-3890, 2000) and belongs to a group of related plasmids with global ubiquity. pfbaot6 is 84,748 bp long and has 94 predicted coding sequences, ... | 2004 | 15574953 |
| associations of the major pseudopilin xpsg with xpsn (gspc) and secretin xpsd of xanthomonas campestris pv. campestris type ii secretion apparatus revealed by cross-linking analysis. | the major pseudopilin xpsg is an essential component of type ii secretion apparatus of xanthomonas campestris pv. campestris. along with other ancillary pseudopilins, it forms a pilus-like structure spanning between cytoplasmic and outer membranes. associations of pseudopilins with non-pseudopilin members of type ii secretion apparatus were not well documented, probably due to their dynamic or unstable nature. in this study, by treating intact cells with a cleavable cross-linker dithiobis(succin ... | 2004 | 15590656 |
| cas3p belongs to a seven-member family of capsule structure designer proteins. | the polysaccharide capsule is the main virulence factor of the basidiomycetous yeast cryptococcus neoformans. four genes (cap10, cap59, cap60, and cap64) essential for capsule formation have been previously identified, although their roles in the biosynthetic pathway remain unclear. a genetic and bioinformatics approach allowed the identification of six cap64-homologous genes, named cas3, cas31, cas32, cas33, cas34, and cas35, in the c. neoformans genome. this gene family is apparently specific ... | 2004 | 15590825 |
| mitochondrial cytochrome c1 is a collapsed di-heme cytochrome. | cytochrome c(1) from mitochondrial complex iii and the di-heme cytochromes c in the corresponding enzyme from epsilon-proteobacteria have so far been considered to represent unrelated cytochromes. a missing link protein discovered in the genome of the hyperthermophilic bacterium aquifex aeolicus, however, provides evidence for a close evolutionary relationship between these two cytochromes. the mono-heme cytochrome c(1) from a. aeolicus contains stretches of strong sequence homology toward the e ... | 2004 | 15591339 |
| the kata catalase gene is regulated by oxyr in both free-living and symbiotic sinorhizobium meliloti. | the characterization of an oxyr insertion mutant provides evidences that kata, which encodes the unique h2o2-inducible hpii catalase, is regulated by oxyr not only in free-living sinorhizobium meliloti but also in symbiotic s. meliloti. moreover, oxyr is expressed independently of exogenous h2o2 and downregulates its own expression in s. meliloti. | 2005 | 15601722 |
| cazfp1, cys2/his2-type zinc-finger transcription factor gene functions as a pathogen-induced early-defense gene in capsicum annuum. | a pepper zinc-finger protein gene, cazfp1 , encoding the cys2/his2-type zinc-finger transcription factor was isolated from pepper leaves inoculated with an avirulent strain bv5-4a of xanthomonas campestris pv. vesicatoria . the cazfp1 protein is a nuclear targeting protein, which functions as a transcriptional regulator. the full-length cazfp1 had no transcriptional activation activity, whereas the c-terminal region of cazfp1 had transactivation activity. the cazfp1 transcripts were constitutive ... | 2004 | 15604723 |
| comprehensive analysis of the extracellular proteins from xanthomonas campestris pv. campestris b100. | the extracellular proteome of xanthomonas campestris pv. campestris (xcc) cultivated in minimal medium was isolated from the cell-free culture supernatant and separated by two-dimensional gel electrophoresis. this technique resolved 97 clearly visible protein spots, which were excised, digested with trypsin and identified on the basis of their peptide mass fingerprints generated by matrix assisted laser desorption/ionisation-time of flight-mass spectrometry. using this approach 87 different prot ... | 2005 | 15619296 |
| the hrpk operon of pseudomonas syringae pv. tomato dc3000 encodes two proteins secreted by the type iii (hrp) protein secretion system: hopb1 and hrpk, a putative type iii translocator. | pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type iii protein secretion system (ttss) and the effector proteins it translocates into plant cells for pathogenicity. the p. syringae ttss is encoded by hrp-hrc genes that reside in a central region of a pathogenicity island (pai). flanking one side of this pai is the exchangeable effector locus (eel). we characterized the transcriptional expression of the open reading frames (orfs) within the eel of p. syri ... | 2005 | 15629936 |