| an integrated genomics approach to define niche establishment by rhodococcus fascians. | rhodococcus fascians is a gram-positive phytopathogen that induces shooty hyperplasia on its hosts through the secretion of cytokinins. global transcriptomics using microarrays combined with profiling of primary metabolites on infected arabidopsis (arabidopsis thaliana) plants revealed that this actinomycete modulated pathways to convert its host into a niche. the transcript data demonstrated that r. fascians leaves a very characteristic mark on arabidopsis with a pronounced cytokinin response i ... | 2009 | 19118125 |
| rhizobia with different symbiotic efficiencies nodulate acaciella angustissima in mexico, including sinorhizobium chiapanecum sp. nov. which has common symbiotic genes with sinorhizobium mexicanum. | bacteria from nodules of the legume acaciella angustissima native to the south of mexico were characterized genetically and their nodulation and competitiveness were evaluated. phylogenetic studies derived from rpob gene sequences indicated that a. angustissima is nodulated by sinorhizobium mexicanum, rhizobium tropici, mesorhizobium plurifarium and agrobacterium tumefaciens and by bacteria related to sinorhizobium americanum, sinorhizobium terangae, rhizobium etli and rhizobium gallicum. a new ... | 2009 | 19120461 |
| engineered saccharomyces cerevisiae that produces 1,3-propanediol from d-glucose. | saccharomyces cerevisiae is a safe micro-organism used in fermentation industry. 1,3-propanediol is an important chemical widely used in polymer production, but its availability is being restricted owing to its expensively chemical synthesis. the aim of this study is to engineer a s. cerevisiae strain that can produce 1,3-propanediol at low cost. | 2008 | 19120627 |
| overexpressed glutamine synthetase gene modifies nitrogen metabolism and abiotic stress responses in rice. | glutamine synthetase (gs; ec 6.3.1.2) is a key enzyme in nitrogen metabolism; it catalyzes the critical incorporation of inorganic ammonium into glutamine. two full-length cdnas that encode the rice (oryza sativa) cytosolic glutamine synthetase1 genes (osgs1;1 and osgs1;2) were isolated from a minghui 63 normalized cdna library, and glna encoding gs in escherichia coli was isolated by pcr amplification. transformants for gs gene (gs1;1, gs1;2, and glna) in rice were produced by an agrobacterium ... | 2009 | 19123004 |
| involvement of shewanella oneidensis mr-1 luxs in biofilm development and sulfur metabolism. | the role of luxs in shewanella oneidensis mr-1 has been examined by transcriptomic profiling, biochemical, and physiological experiments. the results indicate that a mutation in luxs alters biofilm development, not by altering quorum-sensing abilities but by disrupting the activated methyl cycle (amc). the s. oneidensis wild type can produce a luminescence response in the ai-2 reporter strain vibrio harveyi mm32. this luminescence response is abolished upon the deletion of luxs. the deletion of ... | 2009 | 19124589 |
| an hpv 16 l1-based chimeric human papilloma virus-like particles containing a string of epitopes produced in plants is able to elicit humoral and cytotoxic t-cell activity in mice. | even though two prophylactic vaccines against hpv are currently licensed, infections by the virus continue to be a major health problem mainly in developing countries. the cost of the vaccines limits wide-scale application in poor countries. a promising strategy for producing affordable and efficient vaccines involves the expression of recombinant immunogens in plants. several hpv genes have been expressed in plants, including l1, which can self-assemble into virus-like particles. a plant-based, ... | 2009 | 19126233 |
| dihydroorotase from the hyperthermophile aquifex aeolicus is activated by stoichiometric association with aspartate transcarbamoylase and forms a one-pot reactor for pyrimidine biosynthesis. | in prokaryotes, the first three enzymes in pyrimidine biosynthesis, carbamoyl phosphate synthetase (cps), aspartate transcarbamoylase (atc), and dihydroorotase (dho), are commonly expressed separately and either function independently (escherichia coli) or associate into multifunctional complexes (aquifex aeolicus). in mammals the enzymes are expressed as a single polypeptide chain (cad) in the order cps-dho-atc and associate into a hexamer. this study presents the three-dimensional structure of ... | 2009 | 19128030 |
| dynamic intracomplex heterogeneity of phytochrome. | low temperature single-molecule fluorescence emission spectroscopy on individual phytochromes from agrobacterium tumefaciens corroborates findings from ensemble spectroscopy concerning intercomplex heterogeneity. furthermore, time-dependent intracomplex heterogeneity has been observed. | 2009 | 19128172 |
| forca, a promoter element that responds to crosstalk between defense and light signaling. | recognition of pathogenic microorganisms triggers in plants comprehensive transcriptional reprogramming. in order to identify transcriptome-level control elements required for plant immune responses we are examining several sets of genes found by microarray experiments to be co-activated in arabidopsis thaliana (arabidopsis) seedlings infected with the oomycete hyaloperonospora parasitica. promoter motifs conserved in clusters of co-expressed genes may be involved in mediating coordinated gene a ... | 2009 | 19128484 |
| genes involved in arsenic transformation and resistance associated with different levels of arsenic-contaminated soils. | arsenic is known as a toxic metalloid, which primarily exists in inorganic form [as(iii) and as(v)] and can be transformed by microbial redox processes in the natural environment. as(iii) is much more toxic and mobile than as(v), hence microbial arsenic redox transformation has a major impact on arsenic toxicity and mobility which can greatly influence the human health. our main purpose was to investigate the distribution and diversity of microbial arsenite-resistant species in three different a ... | 2009 | 19128515 |
| tobacco arp3 is localized to actin-nucleating sites in vivo. | the polarity of actin is a central determinant of intracellular transport in plant cells. to visualize actin polarity in living plant cells, the tobacco homologue of the actin-related protein 3 (arp3) was cloned and a fusion with the red fluorescent protein (rfp) was generated. upon transient expression of these fusions in the tobacco cell line by-2 (nicotiana tabacum l. cv. bright yellow 2), punctate structures were observed near the nuclear envelope and in the cortical plasma. these dots could ... | 2009 | 19129161 |
| cell culture-induced gradual and frequent epigenetic reprogramming of invertedly repeated tobacco transgene epialleles. | using a two-component transgene system involving two epiallelic variants of the invertedly repeated transgenes in locus 1 (lo1) and a homologous single-copy transgene locus 2 (lo2), we have studied the stability of the methylation patterns and trans-silencing interactions in cell culture and regenerated tobacco (nicotiana tabacum) plants. the posttranscriptionally silenced (ptgs) epiallele of the lo1 trans-silences and trans-methylates the target lo2 in a hybrid (lo1/lo2 line), while its transcr ... | 2009 | 19129419 |
| identification of rhodococcus fascians cytokinins and their modus operandi to reshape the plant. | decades ago, the importance of cytokinins (cks) during rhodococcus fascians pathology had been acknowledged, and an isopentenyltransferase gene had been characterized in the fas operon of the linear virulence plasmid, but hitherto, no specific ck(s) could be associated with virulence. we show that the ck receptors ahk3 and ahk4 of arabidopsis thaliana are essential for symptom development, and that the ck perception machinery is induced upon infection, underlining its central role in the symptom ... | 2009 | 19129491 |
| the arabidopsis g-protein beta-subunit is required for defense response against agrobacterium tumefaciens. | typical early pathogen-associated molecular pattern (pamp) responses include the generation of reactive oxygen species (ros) and map kinase (mapk) activation, but little is known about the molecular mechanisms that link receptor activation to intracellular signal transduction. in this study, we found that in agb1-2 (agb1 null mutation) mutants, ros production triggered by flg22 or elf18 was significantly reduced and that elf18-stimulated pamp-triggered immunity (pti) against agrobacterium tumefa ... | 2009 | 19129659 |
| remodelling of vipa/vipb tubules by clpv-mediated threading is crucial for type vi protein secretion. | the recently identified type vi secretion systems (t6ss) have a crucial function in the virulence of various proteobacteria, including the human pathogen vibrio cholerae. t6ss are encoded by a conserved gene cluster comprising approximately 15 open reading frames, mediating the appearance of hcp and vgrg proteins in cell culture supernatants. here, we analysed the function of the v. cholerae t6ss member clpv, a specialized aaa+ protein. clpv is crucial for a functional t6ss and interacts through ... | 2009 | 19131969 |
| discovery of pathogenicity genes in the crucifer anthracnose fungus colletotrichum higginsianum, using random insertional mutagenesis. | agrobacterium tumefaciens-mediated transformation (atmt) was used for random insertional mutagenesis to identify pathogenicity genes in the hemibiotrophic fungus colletotrichum higginsianum. a high-throughput primary infection assay on arabidopsis thaliana seedlings allowed the rapid screening of 8,850 transformants. forty mutants showing reproducible pathogenicity defects on arabidopsis and brassica plants were obtained, and their infection phenotypes were characterized microscopically. six mut ... | 2009 | 19132867 |
| feeding of mice with arabidopsis thaliana expressing the hiv-1 subtype c p24 antigen gives rise to systemic immune responses. | development of transgenic edible plants, to be used as production, storage and delivery systems for recombinant vaccine antigens, is a promising strategy to obtain cost effective vaccines against infectious diseases, not least for use in developing countries. therefore, we used agrobacterium tumefaciens-mediated gene transfer to introduce the p24 gag gene encoding the nucleocapsid protein from hiv-1 subtype c into the arabidopsis thaliana plant genome. eighteen plant lines were confirmed positiv ... | 2008 | 19132995 |
| insight into the molecular requirements for pathogenicity of fusarium oxysporum f. sp. lycopersici through large-scale insertional mutagenesis. | fusarium oxysporum f. sp. lycopersici is the causal agent of vascular wilt disease in tomato. in order to gain more insight into the molecular processes in f. oxysporum necessary for pathogenesis and to uncover the genes involved, we used agrobacterium-mediated insertional mutagenesis to generate 10,290 transformants and screened the transformants for loss or reduction of pathogenicity. | 2009 | 19134172 |
| high catalase production by rhizobium radiobacter strain 2-1. | to promote the application of catalase for treating wastewater containing hydrogen peroxide, bacteria exhibiting high catalase activity were screened. a bacterium, designated strain 2-1, with high catalase activity was isolated from the wastewater of a beverage factory that uses hydrogen peroxide. strain 2-1 was identified as rhizobium radiobacter (formerly known as agrobacterium tumefaciens) on the basis of both phenotypic and genotypic characterizations. although some strains of r. radiobacter ... | 2008 | 19134550 |
| ampc beta-lactamases. | summary: ampc beta-lactamases are clinically important cephalosporinases encoded on the chromosomes of many of the enterobacteriaceae and a few other organisms, where they mediate resistance to cephalothin, cefazolin, cefoxitin, most penicillins, and beta-lactamase inhibitor-beta-lactam combinations. in many bacteria, ampc enzymes are inducible and can be expressed at high levels by mutation. overexpression confers resistance to broad-spectrum cephalosporins including cefotaxime, ceftazidime, an ... | 2009 | 19136439 |
| the plastidial 2-c-methyl-d-erythritol 4-phosphate pathway provides the isoprenyl moiety for protein geranylgeranylation in tobacco by-2 cells. | protein farnesylation and geranylgeranylation are important posttranslational modifications in eukaryotic cells. we visualized in transformed nicotiana tabacum bright yellow-2 (by-2) cells the geranylgeranylation and plasma membrane localization of gfp-bd-cvil, which consists of green fluorescent protein (gfp) fused to the c-terminal polybasic domain (bd) and cvil isoprenylation motif from the oryza sativa calmodulin, cam61. treatment with fosmidomycin (fos) or oxoclomazone (oc), inhibitors of t ... | 2009 | 19136647 |
| diversity of serine hydrolase activities of unchallenged and botrytis-infected arabidopsis thaliana. | activity-based protein profiling is a powerful method to display enzyme activities in proteomes and provides crucial information on enzyme activity rather than protein or transcript abundance. we applied activity-based protein profiling using fluorophosphonate-based probes to display the activities of ser hydrolases in the model plant arabidopsis thaliana. multidimensional protein identification technology and in-gel analysis of fluorophosphonate-labeled leaf extracts revealed over 50 ser hydrol ... | 2009 | 19136719 |
| the unique branching patterns of deinococcus glycogen branching enzymes are determined by their n-terminal domains. | glycogen branching enzymes (gbe) or 1,4-alpha-glucan branching enzymes (ec 2.4.1.18) introduce alpha-1,6 branching points in alpha-glucans, e.g., glycogen. to identify structural features in gbes that determine their branching pattern specificity, the deinococcus geothermalis and deinococcus radiodurans gbe (gbe(dg) and gbe(dr), respectively) were characterized. compared to other gbes described to date, these deinococcus gbes display unique branching patterns, both transferring relatively short ... | 2009 | 19139240 |
| [microbial community structure of beer wastewater treatment plants analyzed by pcr-dgge technique]. | the microbial community structure of beer wastewater treatment plants with hydrolyze-acidification and sbr process was studied by pcr amplification and denaturing gradient gel electrophoresis (dgge) based 16s rdna. activated sludge samples were collected from both hydrolyze-acidification tank and sbr tank at different depth and disposal period. the total dna was extracted and the 16s rdna was amplified by universal primer. the microbial community structure was analyzed by denaturing gradient gel ... | 2008 | 19143400 |
| coxiella type iv secretion and cellular microbiology. | coxiella burnetii is a widespread zoonotic bacterial pathogen that causes human q fever. in vivo, coxiella displays a tropism for mononuclear phagocytes where it participates in biogenesis of a lysosome-like replication compartment to conduct its obligate intracellular lifestyle. coxiella actively regulates multiple events during infection, presumably via proteins with effector functions that are delivered to the host cytosol by a dot/icm type iv secretion system. because the organism is current ... | 2009 | 19144560 |
| autophagy is enhanced and floral development is impaired in athva22d rna interference arabidopsis. | autophagy is an intracellular process in which a portion of cytoplasm is transported into vacuoles for recycling. physiological roles of autophagy in plants include recycling nutrients during senescence, sustaining life during starvation, and the formation of central digestive vacuoles. the regulation of autophagy and the formation of autophagosomes, spherical double membrane structures containing cytoplasm moving toward vacuoles, are poorly understood. hva22 is a gene originally cloned from bar ... | 2009 | 19151132 |
| chromosome-based genetic complementation system for xylella fastidiosa. | xylella fastidiosa is a xylem-limited, gram-negative bacterium that causes pierce's disease of grapevine. here, we describe the construction of four vectors that facilitate the insertion of genes into a neutral site (ns1) in the x. fastidiosa chromosome. these vectors carry a cole1-like (pmb1) replicon and dna sequences from ns1 flanking a multiple-cloning site and a resistance marker for one of the following antibiotics: chloramphenicol, erythromycin, gentamicin, or kanamycin. in x. fastidiosa, ... | 2009 | 19151176 |
| identification of ena1 as a virulence gene of the human pathogenic fungus cryptococcus neoformans through signature-tagged insertional mutagenesis. | a library of more than 4,500 signature-tagged insertion mutants of the human pathogenic fungus cryptococcus neoformans was generated, and a subset was screened in a murine inhalation model to identify genes required for virulence. new genes that regulate aspects of c. neoformans virulence were also identified by screening the entire library for in vitro phenotypes related to the ability to cause disease, including melanin production, growth at high temperature, and growth under conditions of nut ... | 2009 | 19151325 |
| a key role for heat shock protein 70 in the localization and insertion of tombusvirus replication proteins to intracellular membranes. | plus-stranded rna viruses coopt host proteins to promote their robust replication in infected hosts. tomato bushy stunt tombusvirus (tbsv) is a model virus that can replicate a small replicon rna in saccharomyces cerevisiae and in plants. the tombusvirus replicase complex contains heat shock protein 70 (hsp70), an abundant cytosolic chaperone, which is required for tbsv replication. to dissect the function of hsp70 in tbsv replication, in this paper we use an hsp70 mutant (ssa1 ssa2) yeast strai ... | 2009 | 19153242 |
| effective carbon partitioning driven by exotic phloem-specific regulatory elements fused to the arabidopsis thaliana atsuc2 sucrose-proton symporter gene. | atsuc2 (at1g22710) from arabidopsis thaliana encodes a phloem-localized sucrose/proton symporter required for efficient photoassimilate transport from source tissues to sink tissues. atsuc2 plays a key role in coordinating the demands of sink tissues with the output capacity of source leaves, and in maintaining phloem hydrostatic pressure during changes in plant-water balance. expression and activity are regulated, both positively and negatively, by developmental (sink to source transition) and ... | 2009 | 19154603 |
| a novel pathway for sesquiterpene biosynthesis from z,z-farnesyl pyrophosphate in the wild tomato solanum habrochaites. | in the wild tomato solanum habrochaites, the sst2 locus on chromosome 8 is responsible for the biosynthesis of several class ii sesquiterpene olefins by glandular trichomes. analysis of a trichome-specific est collection from s. habrochaites revealed two candidate genes for the synthesis of sst2-associated sesquiterpenes. zfps encodes a protein with homology to z-isoprenyl pyrophosphate synthases and sbs (for santalene and bergamotene synthase) encodes a terpene synthase with homology to kaurene ... | 2009 | 19155349 |
| conidiation color mutants of aspergillus fumigatus are highly pathogenic to the heterologous insect host galleria mellonella. | the greater wax moth galleria mellonella has been widely used as a heterologous host for a number of fungal pathogens including candida albicans and cryptococcus neoformans. a positive correlation in pathogenicity of these yeasts in this insect model and animal models has been observed. however, very few studies have evaluated the possibility of applying this heterologous insect model to investigate virulence traits of the filamentous fungal pathogen aspergillus fumigatus, the leading cause of i ... | 2009 | 19156203 |
| functional annotation and three-dimensional structure of dr0930 from deinococcus radiodurans, a close relative of phosphotriesterase in the amidohydrolase superfamily. | dr0930, a member of the amidohydrolase superfamily in deinococcus radiodurans, was cloned, expressed, and purified to homogeneity. the enzyme crystallized in the space group p3121, and the structure was determined to a resolution of 2.1 a. the protein folds as a (beta/alpha)7beta-barrel, and a binuclear metal center is found at the c-terminal end of the beta-barrel. the purified protein contains a mixture of zinc and iron and is intensely purple at high concentrations. the purple color was deter ... | 2009 | 19159332 |
| [expression of biologically active recombinant arresten in nicotiana tabacum]. | in this report, the biological activity of the recombinant arresten expressed in nicotiana tabacum was studied. the gene coding for the tumor angiogenesis inhibitor arresten was pcr-amplified from the plasmid pca and its plant expression vector named pcambiaarr was constructed by inserting the arresten cdna fragment into the ncoi/bsteii sites of the plant binary expression vector pcambia1301. then pcambiaarr was transferred into agrobacterium tumefacien lba4404 by the freeze-thaw method. the adv ... | 2008 | 19160831 |
| production of the p24 capsid protein from hiv-1 subtype c in arabidopsis thaliana and daucus carota using an endoplasmic reticulum-directing sekdel sequence in protein expression constructs. | an optimized gene expression construct was designed in order to increase the accumulation of the hiv-1 subtype c p24 protein in arabidopsis thaliana and carrot (daucus carota) plants. an er retention signal was introduced into the genetic construct generating a p24 protein containing a sekdel amino acid sequence at its c-terminus. mature a. thaliana plants and carrot cells were transformed using agrobacterium tumefaciens carrying the improved pgreen0229/p24_sekdel vector. several transgenic plan ... | 2009 | 19167502 |
| roles of agrobacterium tumefaciens rira in iron regulation, oxidative stress response, and virulence. | the analysis of genetics and physiological functions of agrobacterium tumefaciens rira (rhizobial iron regulator) has shown that it is a transcription regulator and a repressor of iron uptake systems. the rira mutant strain (ntlrira) overproduced siderophores and exhibited a highly constitutive expression of genes involved in iron uptake (fhua, irp6a, and fbpa) compared to that of the wild-type strain (ntl4). the deregulation in the iron control of iron uptake in ntlrira led to iron overload in ... | 2009 | 19168612 |
| the signal peptide peptidase is required for pollen function in arabidopsis. | the signal peptide peptidases (spp) are members of the intramembrane cleaving proteases, which are involved in an array of protein-processing and intracellular signaling events in animals. arabidopsis (arabidopsis thaliana) has six genes encoding spp-like proteins, the physiological functions of which are unknown. as a first step in defining the roles of the spps in plants, we examined the distribution and activities of arabidopsis spp (atspp; accession no. at2g03120), the spp-like gene with the ... | 2009 | 19168645 |
| reconfiguring the quorum-sensing regulator sdia of escherichia coli to control biofilm formation via indole and n-acylhomoserine lactones. | sdia is a homolog of quorum-sensing regulators that detects n-acylhomoserine lactone (ahl) signals from other bacteria. escherichia coli uses sdia to reduce its biofilm formation in the presence of both ahls and its own signal indole. here we reconfigured sdia (240 amino acids) to control biofilm formation using protein engineering. four sdia variants were obtained with altered biofilm formation, including truncation variants sdia1e11 (f7l, f59l, y70c, m94k, and k153x) and sdia14c3 (w9r, p49t, n ... | 2009 | 19168658 |
| agrobacterium-mediated transformation of embryogenic tissues of hybrid firs (abies spp.) and regeneration of transgenic emblings. | a genetic transformation system has been developed for selected embryogenic cell lines of hybrids abies alba x a. cephalonica (cell lines ac2, ac78) and abies alba x a. numidica (cell line an72) using agrobacterium tumefaciens. the cell lines were derived from immature or mature zygotic embryos on dcr medium containing ba (1 mg l(-1)). the t-dna of plant transformation vector contained the beta-glucuronidase reporter gene under the control of double dcamv 35s promoter and the neomycin phosphotra ... | 2009 | 19169892 |
| real-time pcr quantification and live-cell imaging of endophytic colonization of barley (hordeum vulgare) roots by fusarium equiseti and pochonia chlamydosporia. | *new tools were developed for the study of the endophytic development of the fungal species fusarium equiseti and pochonia chlamydosporia in barley (hordeum vulgare) roots. these were applied to monitor the host colonization patterns of these potential candidates for biocontrol of root pathogens. * molecular beacons specific for either f. equiseti or p. chlamydosporia were designed and used in real-time polymerase chain reaction (pcr) quantification of fungal populations in roots. genetic transf ... | 2009 | 19170898 |
| use of folding modulators to improve heterologous protein production in escherichia coli. | abstract: despite the fundamental importance of e. coli in the manufacture of a wide range of biotechnological and biomedical products, extensive process and/or target optimisation is routinely required in order to achieve functional yields in excess of low mg/l levels. molecular chaperones and folding catalysts appear to present a panacea for problems of heterologous protein folding in the organism, due largely to their broad substrate range compared with, e.g., protein-specific mutagenesis app ... | 2009 | 19173718 |
| enzyme activities and subcellular localization of members of the arabidopsis glutathione transferase superfamily. | enzyme screens with strep-tagged recombinant proteins and expression studies with the respective green fluorescent protein (gfp) fusions have been employed to examine the functional activities and subcellular localization of members of the arabidopsis glutathione transferase (gst) superfamily. fifty-one of 54 gst family members were transcribed and 41 found to express as functional glutathione-dependent enzymes in escherichia coli. functional redundancy was observed and in particular three theta ... | 2009 | 19174456 |
| roles of dna adenine methylation in host-pathogen interactions: mismatch repair, transcriptional regulation, and more. | the dna adenine methyltransferase (dam methylase) of gammaproteobacteria and the cell cycle-regulated methyltransferase (ccrm) methylase of alphaproteobacteria catalyze an identical reaction (methylation of adenosine moieties using s-adenosyl-methionine as a methyl donor) at similar dna targets (gatc and gantc, respectively). dam and ccrm are of independent evolutionary origin. each may have evolved from an ancestral restriction-modification system that lost its restriction component, leaving an ... | 2009 | 19175412 |
| eukaryotic protein production in designed storage organelles. | protein bodies (pbs) are natural endoplasmic reticulum (er) or vacuole plant-derived organelles that stably accumulate large amounts of storage proteins in seeds. the proline-rich n-terminal domain derived from the maize storage protein gamma zein (zera) is sufficient to induce pbs in non-seed tissues of arabidopsis and tobacco. this zera property opens up new routes for high-level accumulation of recombinant proteins by fusion of zera with proteins of interest. in this work we extend the advant ... | 2009 | 19175916 |
| polar localization of virulence-related esx-1 secretion in mycobacteria. | the esx-1 (type vii) secretion system is critical for virulence of both mycobacterium tuberculosis and mycobacterium marinum, and is highly conserved between the two species. despite its importance, there has been no direct visualization of esx-1 secretion until now. in m. marinum, we show that secretion of mh3864, a novel esx-1 substrate that remains partially cell wall-associated after translocation, occurred in polar regions, indicating that esx-1 secretion takes place in these regions. analy ... | 2009 | 19180234 |
| pathway of gamma-aminobutyrate metabolism in rhizobium leguminosarum 3841 and its role in symbiosis. | pea plants incubated in 15n2 rapidly accumulated labeled gamma-aminobutyrate (gaba) in the plant cytosol and in bacteroids of rhizobium leguminosarum bv. viciae 3841. two pathways of gaba metabolism were identified in r. leguminosarum 3841. in the first, glutamate is formed by gaba aminotransferase (gabt), transferring the amino group from gaba to 2-oxoglutarate. in the second, alanine is formed by two omega-aminotransferases (opaa and opab), transferring the amino group from gaba to pyruvate. w ... | 2009 | 19181799 |
| different biochemical mechanisms ensure network-wide balancing of reducing equivalents in microbial metabolism. | to sustain growth, the catabolic formation of the redox equivalent nadph must be balanced with the anabolic demand. the mechanisms that ensure such network-wide balancing, however, are presently not understood. based on 13c-detected intracellular fluxes, metabolite concentrations, and cofactor specificities for all relevant central metabolic enzymes, we have quantified catabolic nadph production in agrobacterium tumefaciens, bacillus subtilis, escherichia coli, paracoccus versutus, pseudomonas f ... | 2009 | 19181802 |
| in vitro characterization of the enzyme properties of the phospholipid n-methyltransferase pmta from agrobacterium tumefaciens. | agrobacterium tumefaciens requires phosphatidylcholine (pc) in its membranes for plant infection. the phospholipid n-methyltransferase pmta catalyzes all three transmethylation reactions of phosphatidylethanolamine (pe) to pc via the intermediates monomethylphosphatidylethanolamine (mmpe) and dimethylphosphatidylethanolamine (dmpe). the enzyme uses s-adenosylmethionine (sam) as the methyl donor, converting it to s-adenosylhomocysteine (sah). little is known about the activity of bacterial pmt en ... | 2009 | 19181804 |
| construction of disarmed ti plasmids transferable between escherichia coli and agrobacterium species. | agrobacterium-mediated plant transformation has been used widely, but there are plants that are recalcitrant to this type of transformation. this transformation method uses bacterial strains harboring a modified tumor-inducing (ti) plasmid that lacks the transfer dna (t-dna) region (disarmed ti plasmid). it is desirable to develop strains that can broaden the host range. a large number of agrobacterium strains have not been tested yet to determine whether they can be used in transformation. in o ... | 2009 | 19181833 |
| heterologous expression analyses of rice oscas in arabidopsis and in yeast provide evidence for its roles in cyanide detoxification rather than in cysteine synthesis in vivo. | while most dicot plants produce little ethylene in their vegetative stage, many monocots such as rice liberate a relatively large amount of ethylene with cyanide as a co-product in their seedling stage when etiolated. one of the known functions of beta-cyanoalanine synthase (cas) is to detoxify the co-product cyanide during ethylene biosynthesis in higher plants. based on a tryptic peptide sequence obtained from a partially purified cas activity protein preparation in etiolated rice seedlings, t ... | 2009 | 19181864 |
| haca-dependent transcriptional switch releases haca mrna from a translational block upon endoplasmic reticulum stress. | activation of the unfolded protein response (upr) in eukaryotes involves the splicing of an unconventional intron from the mrna encoding the transcriptional activator of the pathway. in saccharomyces cerevisiae a 252-nucleotide (nt) unconventional intron is spliced out of the transcript of hac1, changing the 3' end of the hac1 open reading frame and relieving the transcript from a translational block in a single step. the translational block is caused by the base pairing of part of the unconvent ... | 2009 | 19181870 |
| sequence mining and transcript profiling to explore cyst nematode parasitism. | cyst nematodes are devastating plant parasites that become sedentary within plant roots and induce the transformation of normal plant cells into elaborate feeding cells with the help of secreted effectors, the parasitism proteins. these proteins are the translation products of parasitism genes and are secreted molecular tools that allow cyst nematodes to infect plants. | 2009 | 19183474 |
| rapid system for evaluating bioproduction capacity of complex pharmaceutical proteins in plants. | transgene product yield remains a key limitation in commercializing plant-derived pharmaceutical proteins. although significant progress has been made in understanding the roles of promoters, enhancers, integration sites, codon usage, cryptic rna sites, silencing, and product compartmentalization on product yield and quality, researchers still cannot reliably predict which proteins will be produced at high levels or what manipulations will guarantee enhanced productivity. we have optimized a sim ... | 2009 | 19183893 |
| genome sequence of desulfobacterium autotrophicum hrm2, a marine sulfate reducer oxidizing organic carbon completely to carbon dioxide. | sulfate-reducing bacteria (srb) belonging to the metabolically versatile desulfobacteriaceae are abundant in marine sediments and contribute to the global carbon cycle by complete oxidation of organic compounds. desulfobacterium autotrophicum hrm2 is the first member of this ecophysiologically important group with a now available genome sequence. with 5.6 megabasepairs (mbp) the genome of db. autotrophicum hrm2 is about 2 mbp larger than the sequenced genomes of other sulfate reducers (srb). a h ... | 2009 | 19187283 |
| atrazine degradation by stable mixed cultures enriched from agricultural soil and their characterization. | the aim of this work was to enrich stable mixed cultures from atrazine-contaminated soil. the cultures were examined for their atrazine biodegradation efficiencies in comparison with j14a, a known atrazine-degrading strain of agrobacterium radiobacter. the cultures were also characterized to identify community structure and bacterial species present. | 2009 | 19191954 |
| a cis element within flowering locus t mrna determines its mobility and facilitates trafficking of heterologous viral rna. | the arabidopsis flowering locus t (ft) gene encodes the mobile florigen essential for floral induction. while movement of the ft protein has been shown to occur within plants, systemic spread of ft mrna remains to be unequivocally demonstrated. utilizing novel rna mobility assay vectors based on two distinct movement-defective viruses, potato virus x and turnip crinkle virus, and an agroinfiltration assay, we demonstrate that nontranslatable ft mrna, independent of the ft protein, moves througho ... | 2009 | 19193810 |
| antisense phenotypes reveal a functional expression of osarf1, an auxin response factor, in transgenic rice. | osarf1 is the first full-length member of auxin response factor (arf) gene family to be cloned from monocot plant. using quantitative rt-pcr this study found that, the transcript abundance of osarf1 was significantly higher in embryonic tissues than in vegetative tissues. to investigate the effect of osarf1 on the phenotype of rice, a cdna fragment of osarf1 was inserted in inverse orientation to the 35s promoter in vector pbin438 to produce an antisense (as) construction. the as-osarf1 construc ... | 2009 | 19193962 |
| rickettsia phylogenomics: unwinding the intricacies of obligate intracellular life. | completed genome sequences are rapidly increasing for rickettsia, obligate intracellular alpha-proteobacteria responsible for various human diseases, including epidemic typhus and rocky mountain spotted fever. in light of phylogeny, the establishment of orthologous groups (ogs) of open reading frames (orfs) will distinguish the core rickettsial genes and other group specific genes (class 1 ogs or c1ogs) from those distributed indiscriminately throughout the rickettsial tree (class 2 og or c2ogs) ... | 2008 | 19194535 |
| optimization and biochemical characterization of a bacteriocin from a newly isolated bacillus subtilis strain 14b for biocontrol of agrobacterium spp. strains. | the identification of a new compound active against agrobacterium tumefaciens. | 2009 | 19196444 |
| a burkholderia cenocepacia orphan luxr homolog is involved in quorum-sensing regulation. | burkholderia cenocepacia utilizes quorum sensing to control gene expression, including the expression of genes involved in virulence. in addition to cepr and ccir, a third luxr homolog, cepr2, was found to regulate gene expression and virulence factor production. all b. cenocepacia strains examined contained this orphan luxr homolog, which was not associated with an adjacent n-acyl-homoserine lactone synthase gene. expression of cepr2 was negatively autoregulated and was negatively regulated by ... | 2009 | 19201791 |
| identification of an rsh gene from a novosphingobium sp. necessary for quorum-sensing signal accumulation. | the stringent response is a mechanism by which bacteria adapt to environmental stresses and nutritional deficiencies through the synthesis and hydrolysis of (p)ppgpp by rela/spot enzymes. alphaproteobacteria and plants contain a single rsh enzyme (named for rela/spot homolog) that is bifunctional. here we report the identification of a new species of bacteria belonging to the genus novosphingobium and characterization of an rsh mutation in this plant tumor-associated isolate. isolate rr 2-17, fr ... | 2009 | 19201802 |
| catalytic improvement and evolution of atrazine chlorohydrolase. | the atrazine chlorohydrolase atza has evolved within the past 50 years to catalyze the hydrolytic dechlorination of the herbicide atrazine. it is of wide research interest for two reasons: first, catalytic improvement of the enzyme would facilitate its application in bioremediation, and second, because of its recent evolution, it presents a rare opportunity to examine the early stages in the acquisition of new catalytic activities. using a structural model of the atza-atrazine complex, a region ... | 2009 | 19201959 |
| transcriptome profiling of the mangrove plant bruguiera gymnorhiza and identification of salt tolerance genes by agrobacterium functional screening. | to identify key genes in the regulation of salt tolerance in the mangrove plant bruguiera gymnorhiza, transcriptome profiling in the lateral and main roots under conditions of salt stress was performed. statistical analysis revealed that 175 and 403 of 11,997 genes shoewd significantly increased high expression in the lateral and main roots respectively. one hundred and sixty genes were up-regulated in both types of roots in the early time period, 1 to 12 h after salt treatment. expression vecto ... | 2009 | 19202291 |
| irre, a global regulator of extreme radiation resistance in deinococcus radiodurans, enhances salt tolerance in escherichia coli and brassica napus. | globally, about 20% of cultivated land is now affected by salinity. salt tolerance is a trait of importance to all crops in saline soils. previous efforts to improve salt tolerance in crop plants have met with only limited success. bacteria of the genus deinococcus are known for their ability to survive highly stressful conditions, and therefore possess a unique pool of genes conferring extreme resistance. in deinococcus radiodurans, the irre gene encodes a global regulator responsible for extre ... | 2009 | 19204796 |
| high abundance of virulence gene homologues in marine bacteria. | marine bacteria can cause harm to single-celled and multicellular eukaryotes. however, relatively little is known about the underlying genetic basis for marine bacterial interactions with higher organisms. we examined whole-genome sequences from a large number of marine bacteria for the prevalence of homologues to virulence genes and pathogenicity islands known from bacteria that are pathogenic to terrestrial animals and plants. as many as 60 out of 119 genomes of marine bacteria, with no known ... | 2009 | 19207573 |
| the ataxia protein sacsin is a functional co-chaperone that protects against polyglutamine-expanded ataxin-1. | an extensive protein-protein interaction network has been identified between proteins implicated in inherited ataxias. the protein sacsin, which is mutated in the early-onset neurodegenerative disease autosomal recessive spastic ataxia of charlevoix-saguenay, is a node in this interactome. here, we have established the neuronal expression of sacsin and functionally characterized domains of the 4579 amino acid protein. sacsin is most highly expressed in large neurons, particularly within brain mo ... | 2009 | 19208651 |
| arabidopsis cam binding protein cbp60g contributes to mamp-induced sa accumulation and is involved in disease resistance against pseudomonas syringae. | salicylic acid (sa)-induced defense responses are important factors during effector triggered immunity and microbe-associated molecular pattern (mamp)-induced immunity in plants. this article presents evidence that a member of the arabidopsis cbp60 gene family, cbp60g, contributes to mamp-triggered sa accumulation. cbp60g is inducible by both pathogen and mamp treatments. pseudomonas syringae growth is enhanced in cbp60g mutants. expression profiles of a cbp60g mutant after mamp treatment are si ... | 2009 | 19214217 |
| the dominant hc.sdh (r) carboxin-resistance gene of the ectomycorrhizal fungus hebeloma cylindrosporum as a selectable marker for transformation. | in an attempt to get a marker gene suitable for genetical transformation of the ectomycorrhizal fungus hebeloma cylindrosporum, the gene hc.sdh (r) that confers carboxin-resistance was isolated from a uv mutant of this fungus. it encodes a mutant allele of the fe-s subunit of the succinate dehydrogenase gene that carries a single amino acid substitution known to confer carboxin-resistance. this gene was successfully used as the selective marker to transform, via agrobacterium tumefaciens, monoka ... | 2009 | 19214514 |
| rapid host adaptation by extensive recombination. | experimental investigations into virus recombination can provide valuable insights into the biochemical mechanisms and the evolutionary value of this fundamental biological process. here, we describe an experimental scheme for studying recombination that should be applicable to any recombinogenic viruses amenable to the production of synthetic infectious genomes. our approach is based on differences in fitness that generally exist between synthetic chimaeric genomes and the wild-type viruses fro ... | 2009 | 19218220 |
| genome activation by raspberry bushy dwarf virus coat protein. | two sets of infectious cdna clones of raspberry bushy dwarf virus (rbdv) have been constructed, enabling either the synthesis of infectious rna transcripts or the delivery of infectious binary plasmid dna by infiltration of agrobacterium tumefaciens. in whole plants and in protoplasts, inoculation of rbdv rna1 and rna2 transcripts led to a low level of infection, which was greatly increased by the addition of rna3, a subgenomic rna coding for the rbdv coat protein (cp). agroinfiltration of rna1 ... | 2009 | 19218221 |
| inhibition of tobacco mosaic virus movement by expression of an actin-binding protein. | the tobacco mosaic virus (tmv) movement protein (mp) required for the cell-to-cell spread of viral rna interacts with the endoplasmic reticulum (er) as well as with the cytoskeleton during infection. whereas associations of mp with er and microtubules have been intensely investigated, research on the role of actin has been rather scarce. we demonstrate that nicotiana benthamiana plants transgenic for the actin-binding domain 2 of arabidopsis (arabidopsis thaliana) fimbrin (atfim1) fused to green ... | 2009 | 19218363 |
| x-ray crystallographic and mutational studies of fluoroacetate dehalogenase from burkholderia sp. strain fa1. | fluoroacetate dehalogenase catalyzes the hydrolytic defluorination of fluoroacetate to produce glycolate. the enzyme is unique in that it catalyzes the cleavage of a carbon-fluorine bond of an aliphatic compound: the bond energy of the carbon-fluorine bond is among the highest found in natural products. the enzyme also acts on chloroacetate, although much less efficiently. we here determined the x-ray crystal structure of the enzyme from burkholderia sp. strain fa1 as the first experimentally de ... | 2009 | 19218394 |
| nuclear activity of roxy1, a glutaredoxin interacting with tga factors, is required for petal development in arabidopsis thaliana. | glutaredoxins (grxs) have thus far been associated mainly with redox-regulated processes participating in stress responses. however, roxy1, encoding a grx, has recently been shown to regulate petal primorida initiation and further petal morphogenesis in arabidopsis thaliana. roxy1 belongs to a land plant-specific class of grxs that has a cc-type active site motif, which deviates from ubiquitously occurring cpyc and cgfs grxs. expression studies of yellow fluorescent protein-roxy1 fusion genes dr ... | 2009 | 19218396 |
| functional expression of a bacterial xylose isomerase in saccharomyces cerevisiae. | in industrial fermentation processes, the yeast saccharomyces cerevisiae is commonly used for ethanol production. however, it lacks the ability to ferment pentose sugars like d-xylose and l-arabinose. heterologous expression of a xylose isomerase (xi) would enable yeast cells to metabolize xylose. however, many attempts to express a prokaryotic xi with high activity in s. cerevisiae have failed so far. we have screened nucleic acid databases for sequences encoding putative xis and finally were a ... | 2009 | 19218403 |
| production of the phytohormone indole-3-acetic acid by estuarine species of the genus vibrio. | strains of vibrio spp. isolated from roots of the estuarine grasses spartina alterniflora and juncus roemerianus produce the phytohormone indole-3-acetic acid (iaa). the colorimetric salkowski assay was used for initial screening of iaa production. gas chromatography-mass spectroscopy (gc-ms) was then employed to confirm and quantify iaa production. the accuracy of iaa quantification by the salkowski assay was examined by comparison to gc-ms assay values. indole-3-acetamide, an intermediate in i ... | 2009 | 19218411 |
| mutation in sco affects cytochrome c assembly and alters oxidative stress resistance in agrobacterium tumefaciens. | sco (for the synthesis of cytochrome c oxidase) is a mitochondrial membrane protein essential for the correct assembly of cytochrome c oxidase. sco homolog genes exist in a wide variety of bacterial species. inactivation of agrobacterium tumefaciens sco leads to markedly decreased cytochrome c oxidase activity. this phenotype can be complemented by either supplementing the culture medium with copper or by a plasmid containing sco. the sco mutant also alters resistance to a superoxide generator m ... | 2009 | 19220469 |
| high frequency agrobacterium tumefaciens-mediated plant transformation induced by ammonium nitrate. | success in plant genetic transformation depends on the efficiency of explant regeneration and transgene integration. whereas the former one depends on explant totipotency, the latter depends on the activity of host dna repair and chromatin organisation factors. we analyzed whether factors that result in an increase in recombination frequency can also increase transformation efficiency. here, we report that a threefold increase in the concentration of nh(4)no(3) in the growth medium results in mo ... | 2009 | 19221758 |
| nitrile-specifier proteins involved in glucosinolate hydrolysis in arabidopsis thaliana. | glucosinolates are plant secondary metabolites present in brassicaceae plants such as the model plant arabidopsis thaliana. intact glucosinolates are believed to be biologically inactive, whereas degradation products after hydrolysis have multiple roles in growth regulation and defense. the degradation of glucosinolates is catalyzed by thioglucosidases called myrosinases and leads by default to the formation of isothiocyanates. the interaction of a protein called epithiospecifier protein (esp) w ... | 2009 | 19224919 |
| production of native and modified recombinant der p 1 molecules in tobacco plants. | as a complex molecule requiring post-translational processing, it has been difficult to produce the der p 1 major allergen from the dermatophagoides pteronyssinus house dust mite in a recombinant form. | 2009 | 19226276 |
| metagenomics revealed a quorum quenching lactonase qlca from yet unculturable soil bacteria. | quorum sensing (qs) is a signal mediated cell-cell communication system that couples bacterial cell density to a synchronized gene expression (fuqua et al., 1994). mostly, in gram negative bacteria qs signals are n-acylhomoserine lactones (nahls) that coordinate important functions such as virulence and pathogenicity. qs signals or the elements involved in their production or perception could be targeted to disrupt qs, a phenomenon called quorum quenching (qq). qq properties (chemicals and enzym ... | 2008 | 19226736 |
| genetic evidence for cheb- and cher-dependent chemotaxis system in a. tumefaciens toward acetosyringone. | agrobacterium tumefaciens has homologues of chemotaxis genes of the alpha-subgroup of proteobacteria, which include orf1, orf2, chey1, chea, cher, cheb, chey2, orf9, and orf10 and organized in one operon [wright et al. a chemotaxis cluster from agrobacterium tumefaciens. gene 1998;220:83-9]. two mutants of a. tumefaciens were created by in-frame deletions of cheb and cher using suicide vector, pk18mobsacb. the chemosensory behaviour of mutants studied on swarm plates and in blind-well chemotaxis ... | 2009 | 19231145 |
| multidrug resistance in bacteria. | large amounts of antibiotics used for human therapy, as well as for farm animals and even for fish in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. multidrug resistance in bacteria may be generated by one of two mechanisms. first, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. this accumulation occurs typically on resistance (r) plasmids. second, multidrug resistance may also occur by t ... | 2009 | 19231985 |
| subcellular localization and functional analysis of the arabidopsis gtpase rabe. | membrane trafficking plays a fundamental role in eukaryotic cell biology. of the numerous known or predicted protein components of the plant cell trafficking system, only a relatively small subset have been characterized with respect to their biological roles in plant growth, development, and response to stresses. in this study, we investigated the subcellular localization and function of an arabidopsis (arabidopsis thaliana) small gtpase belonging to the rabe family. rabe proteins are phylogene ... | 2009 | 19233904 |
| drought stress-induced rma1h1, a ring membrane-anchor e3 ubiquitin ligase homolog, regulates aquaporin levels via ubiquitination in transgenic arabidopsis plants. | ubiquitination is involved in a variety of biological processes, but the exact role of ubiquitination in abiotic responses is not clearly understood in higher plants. here, we investigated rma1h1, a hot pepper (capsicum annuum) homolog of a human ring membrane-anchor 1 e3 ubiquitin (ub) ligase. bacterially expressed rma1h1 displayed e3 ub ligase activity in vitro. rma1h1 was rapidly induced by various abiotic stresses, including dehydration, and its overexpression in transgenic arabidopsis thali ... | 2009 | 19234086 |
| brome mosaic virus capsid protein regulates accumulation of viral replication proteins by binding to the replicase assembly rna element. | viruses provide valuable insights into the regulation of molecular processes. brome mosaic virus (bmv) is one of the simplest entities with four viral proteins and three genomic rnas. here we report that the bmv capsid protein (cp), which functions in rna encapsidation and virus trafficking, also represses viral rna replication in a concentration-dependent manner by inhibiting the accumulation of the rna replication proteins. expression of the replication protein 2a in trans can partially rescue ... | 2009 | 19237464 |
| quorum sensing: a new biofouling control paradigm in a membrane bioreactor for advanced wastewater treatment. | bacteria regulate specific group behaviors such as biofilm formation in response to population density using small signal molecules called autoinducers (quorum sensing, qs). in this study, the concept of bacterial qs was applied to membrane bioreactors (mbrs) for advanced wastewater treatment as a new biofouling control paradigm. the research was conducted in three phases: (1) demonstrate the presence of the autoinducer signal in mbrs, (2) correlate qs activity and membrane biofouling, (3) apply ... | 2009 | 19238968 |
| a rice gene of de novo origin negatively regulates pathogen-induced defense response. | how defense genes originated with the evolution of their specific pathogen-responsive traits remains an important problem. it is generally known that a form of duplication can generate new genes, suggesting that a new gene usually evolves from an ancestral gene. however, we show that a new defense gene in plants may evolve by de novo origination, resulting in sophisticated disease-resistant functions in rice. analyses of gene evolution showed that this new gene, osdr10, had homologs only in the ... | 2009 | 19240804 |
| a bacterial-type abc transporter is involved in aluminum tolerance in rice. | aluminum (al) toxicity is a major factor limiting crop production in acidic soil, but the molecular mechanisms of al tolerance are poorly understood. here, we report that two genes, star1 (for sensitive to al rhizotoxicity1) and star2, are responsible for al tolerance in rice. star1 encodes a nucleotide binding domain, while star2 encodes a transmembrane domain, of a bacterial-type atp binding cassette (abc) transporter. disruption of either gene resulted in hypersensitivity to aluminum toxicity ... | 2009 | 19244140 |
| the crystal structures of the open and catalytically competent closed conformation of escherichia coli glycogen synthase. | escherichia coli glycogen synthase (ecgs, ec 2.4.1.21) is a retaining glycosyltransferase (gt) that transfers glucose from adenosine diphosphate glucose to a glucan chain acceptor with retention of configuration at the anomeric carbon. ecgs belongs to the gt-b structural superfamily. here we report several ecgs x-ray structures that together shed considerable light on the structure and function of these enzymes. the structure of the wild-type enzyme bound to adp and glucose revealed a 15.2 degre ... | 2009 | 19244233 |
| nuclear shuttling of she2p couples ash1 mrna localization to its translational repression by recruiting loc1p and puf6p. | the transport and localization of mrnas results in the asymmetric synthesis of specific proteins. in yeast, the nucleocytoplasmic shuttling protein she2 binds the ash1 mrna and targets it for localization at the bud tip by recruiting the she3p-myo4p complex. although the cytoplasmic role of she2p in mrna localization is well characterized, its nuclear function is still unclear. here, we show that she2p contains a nonclassical nuclear localization signal (nls) that is essential for its nuclear im ... | 2009 | 19244342 |
| preferential up-regulation of g2/m phase-specific genes by overexpression of the hyperactive form of ntmyba2 lacking its negative regulation domain in tobacco by-2 cells. | many g2/m phase-specific genes in plants contain mitosis-specific activator (msa) elements, which act as g2/m phase-specific enhancers and bind with r1r2r3-myb transcription factors. here, we examined the genome-wide effects of ntmyba2 overexpression, one of the r1r2r3-myb transcription factors in tobacco (nicotiana tabacum). we used a custom-made 16-k cdna microarray for comparative transcriptome analysis of transgenic tobacco by-2 cell lines that overexpress ntmyba2 or its truncated hyperactiv ... | 2009 | 19244455 |
| ntcp56, a new cysteine protease in nicotiana tabacum l., involved in pollen grain development. | proteinases play a critical role in developmental homeostasis and in response to environ-mental stimuli. our present research reports that a new cysteine protease, ntcp56, is involved in the development of pollen grains in nicotiana tabacum l. the ntcp56 gene, which encodes a protein of 361 amino acid residues with a calculated molecular mass of 40 kda, is strongly expressed in anthers. the recombinant ntcp56 showed a high activity towards casein. kinetic analysis revealed a k(m) of 2.20 mg ml(- ... | 2009 | 19246592 |
| molecular evolution of a viral non-coding sequence under the selective pressure of amirna-mediated silencing. | plant micrornas (mirna) guide cleavage of target mrnas by dicer-like proteins, thereby reducing mrna abundance. native precursor mirnas can be redesigned to target rnas of interest, and one application of such artificial microrna (amirna) technology is to generate plants resistant to pathogenic viruses. transgenic arabidopsis plants expressing amirnas designed to target the genome of two unrelated viruses were resistant, in a highly specific manner, to the appropriate virus. here, we pursued two ... | 2009 | 19247440 |
| structural determinants of the high thermal stability of ssopox from the hyperthermophilic archaeon sulfolobus solfataricus. | organophosphates (ops) constitute the largest class of insecticides used worldwide and certain of them are potent nerve agents. consequently, enzymes degrading ops are of paramount interest, as they could be used as bioscavengers and biodecontaminants. looking for a stable ops catalyst, able to support industrial process constraints, a hyperthermophilic phosphotriesterase (pte) (ssopox) was isolated from the archaeon sulfolobus solfataricus and was found to be highly thermostable. the solved 3d ... | 2009 | 19247785 |
| a novel plasmid for detection of n-acyl homoserine lactones. | many bacteria utilize acyl-homoserine lactones as cell to cell signals that can regulate the expression of numerous genes. structural differences in acyl-homoserine lactones produced by different bacteria, such as acyl side chain length and the presence or absence of an oxy group, make many of the commonly used detection bioassays impractical for broad range detection. here we present a simple, broad range acyl-homoserine lactone detection bioassay that can be used to detect a wide range of thes ... | 2009 | 19248807 |
| protocol: streamlined sub-protocols for floral-dip transformation and selection of transformants in arabidopsis thaliana. | abstract: generating and identifying transformants is essential for many studies of gene function. in arabidopsis thaliana, a revolutionary protocol termed floral dip is now the most widely used transformation method. although robust, it involves a number of relatively time-consuming and laborious steps, including manipulating an agrobacterium tumefaciens culture and aseptic procedures for the selection of plant lines harboring antibiotic-selection markers. furthermore, where multiple transgenes ... | 2009 | 19250520 |
| genome sequences of three agrobacterium biovars help elucidate the evolution of multichromosome genomes in bacteria. | the family rhizobiaceae contains plant-associated bacteria with critical roles in ecology and agriculture. within this family, many rhizobium and sinorhizobium strains are nitrogen-fixing plant mutualists, while many strains designated as agrobacterium are plant pathogens. these contrasting lifestyles are primarily dependent on the transmissible plasmids each strain harbors. members of the rhizobiaceae also have diverse genome architectures that include single chromosomes, multiple chromosomes, ... | 2009 | 19251847 |
| mqo, a tricarboxylic acid cycle enzyme, is required for virulence of pseudomonas syringae pv. tomato strain dc3000 on arabidopsis thaliana. | plant pathogenic bacteria, such as pseudomonas syringae pv. tomato strain dc3000, the causative agent of tomato bacterial speck disease, grow to high levels in the apoplastic space between plant cells. colonization of plant tissue requires expression of virulence factors that modify the apoplast to make it more suitable for pathogen growth or facilitate adaptation of the bacteria to the apoplastic environment. to identify new virulence factors involved in these processes, dc3000 tn5 transposon i ... | 2009 | 19251849 |
| interactions between brucella suis virb8 and its homolog traj from the plasmid psb102 underline the dynamic nature of type iv secretion systems. | the proteinvirb8 plays a critical role in the assembly and function of the agrobacterium tumefaciens virb type iv secretion system (t4ss). the structure of the periplasmic domain of both a. tumefaciens and brucella suis virb8 has been determined, and site-directed mutagenesis has revealed amino acids involved in the dimerization of virb8 and interactions with virb4 and virb10. we have shown previously that traj, the virb8 homologue from psb102, and the chimeric protein trajb8, encompassing the c ... | 2009 | 19251859 |
| gras proteins form a dna binding complex to induce gene expression during nodulation signaling in medicago truncatula. | the symbiotic association of legumes with rhizobia involves bacterially derived nod factor, which is sufficient to activate the formation of nodules on the roots of the host plant. perception of nod factor by root hair cells induces calcium oscillations that are a component of the nod factor signal transduction pathway. perception of the calcium oscillations is a function of a calcium- and calmodulin-dependent protein kinase, and this activates nodulation gene expression via two gras domain tran ... | 2009 | 19252081 |