| crystallization and preliminary x-ray studies of sdia from escherichia coli. | sdia enhances cell division by regulating the ftsqaz operon in escherichia coli as a transcription activator. in addition, sdia is suggested to play a role in detecting quorum signals that emanate from other species. it is therefore a homologue of luxr, a cognate quorum-sensing receptor that recognizes a quorum signal and activates the quorum responses. to elucidate the role of sdia and its functional and structural relationship to luxr, structural studies were performed on e. coli sdia. recombi ... | 2008 | 18097094 |
| genetic transformation of aloe barbadensis miller by agrobacterium tumefaciens. | despite the importance of aloe in cosmetic and pharmaceutical industries, improvement of aloe (aloe barbadensis miller) by genetic engineering was seldom reported previously. in this study, regeneration and transformation conditions, including explant selection and surface sterilization, use of different agrobacterium strains, and co-culture processing, are optimized. the use of 20.0% sodium hypochloride (25 min) for sterilization was less detrimental to the health of explant than 0.1% mercuric ... | 2007 | 18155617 |
| regulation of rice nadph oxidase by binding of rac gtpase to its n-terminal extension. | reactive oxygen species (ros) produced by nadph oxidase play critical roles in various cellular activities, including plant innate immunity response. in contrast with the large multiprotein nadph oxidase complex of phagocytes, in plants, only the homologs of the catalytic subunit gp91phox and the cytosolic regulator small gtpase rac are found. plant homologs of the gp91phox subunit are known as rboh (for respiratory burst oxidase homolog). although numerous rboh have been isolated in plants, the ... | 2007 | 18156215 |
| rar1 and hsp90 form a complex with rac/rop gtpase and function in innate-immune responses in rice. | a rice (oryza sativa) rac/rop gtpase, os rac1, is involved in innate immunity, but its molecular function is largely unknown. rar1 (for required for mla12 resistance) and hsp90 (a heat shock protein 90 kd) are important components of r gene-mediated disease resistance, and their function is conserved in several plant species. hsp90 has also recently been shown to be important in mammalian innate immunity. however, their functions at the molecular level are not well understood. in this study, we ... | 2007 | 18156216 |
| p-glycoprotein4 displays auxin efflux transporter-like action in arabidopsis root hair cells and tobacco cells. | atp binding cassette (abc) transporters transport diverse substrates across membranes in various organisms. however, plant abc transporters have only been scantily characterized. by taking advantage of the auxin-sensitive arabidopsis thaliana root hair cell and tobacco (nicotiana tabacum) suspension cell systems, we show here that arabidopsis p-glycoprotein4 (pgp4) displays auxin efflux activity in plant cells. root hair cell-specific overexpression of pgp4 (pgp4ox) and known auxin efflux transp ... | 2007 | 18156217 |
| altered utilization of n-acetyl-d-galactosamine by escherichia coli o157:h7 from the 2006 spinach outbreak. | in silico analyses of previously sequenced strains of escherichia coli o157:h7, edl933 and sakai, localized the gene cluster for the utilization of n-acetyl-d-galactosamine (aga) and d-galactosamine (gam). this gene cluster encodes the aga phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) and other catabolic enzymes responsible for transport and catabolism of aga. as the complete coding sequences for enzyme iia (eiia)(aga/gam), eiib(aga), eiic(aga), and eiid(aga) of the aga pts ar ... | 2008 | 18156259 |
| altered utilization of n-acetyl-d-galactosamine by escherichia coli o157:h7 from the 2006 spinach outbreak. | in silico analyses of previously sequenced strains of escherichia coli o157:h7, edl933 and sakai, localized the gene cluster for the utilization of n-acetyl-d-galactosamine (aga) and d-galactosamine (gam). this gene cluster encodes the aga phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) and other catabolic enzymes responsible for transport and catabolism of aga. as the complete coding sequences for enzyme iia (eiia)(aga/gam), eiib(aga), eiic(aga), and eiid(aga) of the aga pts ar ... | 2008 | 18156259 |
| salicylic acid and systemic acquired resistance play a role in attenuating crown gall disease caused by agrobacterium tumefaciens. | we investigated the effects of salicylic acid (sa) and systemic acquired resistance (sar) on crown gall disease caused by agrobacterium tumefaciens. nicotiana benthamiana plants treated with sa showed decreased susceptibility to agrobacterium infection. exogenous application of sa to agrobacterium cultures decreased its growth, virulence, and attachment to plant cells. using agrobacterium whole-genome microarrays, we characterized the direct effects of sa on bacterial gene expression and showed ... | 2008 | 18156296 |
| outcome of bacteremia and fungemia in paediatric oncology patients. | to determine the outcome of paediatric oncology patients with positive blood cultures. | 2002 | 18159414 |
| cis- and trans-acting functions of brome mosaic virus protein 1a in genomic rna1 replication. | rna viruses employ a combination of mechanisms to regulate their gene expression and replication. brome mosaic virus (bmv) is a tripartite positive-strand rna virus used to study the requirements for virus infection. bmv genomic rna1 encodes protein 1a, which contains a methyltransferase (mt) domain and a helicase domain that are required for replication. 1a forms a complex with the 2a rna-dependent rna polymerase for the replication and transcription of all bmv rnas. rna1 expressed with 2a from ... | 2008 | 18160434 |
| cis- and trans-acting functions of brome mosaic virus protein 1a in genomic rna1 replication. | rna viruses employ a combination of mechanisms to regulate their gene expression and replication. brome mosaic virus (bmv) is a tripartite positive-strand rna virus used to study the requirements for virus infection. bmv genomic rna1 encodes protein 1a, which contains a methyltransferase (mt) domain and a helicase domain that are required for replication. 1a forms a complex with the 2a rna-dependent rna polymerase for the replication and transcription of all bmv rnas. rna1 expressed with 2a from ... | 2008 | 18160434 |
| gebp and gebp-like proteins are noncanonical leucine-zipper transcription factors that regulate cytokinin response in arabidopsis. | understanding the role of transcription factors (tfs) is essential in reconstructing developmental regulatory networks. the plant-specific gebp tf family of arabidopsis thaliana (arabidopsis) comprises 21 members, all of unknown function. a subset of four members, the founding member gebp and gebp-like proteins (gpl) 1, 2, and 3, shares a conserved c-terminal domain. here we report that gebp/gpl genes represent a newly defined class of leucine-zipper (leu-zipper) tfs and that they play a redunda ... | 2008 | 18162594 |
| the type iv secretion system component virb5 binds to the trans-zeatin biosynthetic enzyme tzs and enables its translocation to the cell surface of agrobacterium tumefaciens. | virb5 is a minor component of the extracellular t pilus determined by the agrobacterium tumefaciens type iv secretion system. to identify proteins that interact with virb5 during the pilus assembly process, we purified virb5 as a recombinant fusion protein and, by using a gel overlay assay, we detected a 26-kda interacting protein in agrobacterium cell lysates. the virb5-binding protein was purified from a. tumefaciens and identified as the cytokinin biosynthetic enzyme tzs. the virb5-tzs intera ... | 2008 | 18165307 |
| interaction with host sgs3 is required for suppression of rna silencing by tomato yellow leaf curl virus v2 protein. | the v2 protein of tomato yellow leaf curl geminivirus (tylcv) functions as an rna-silencing suppressor that counteracts the innate immune response of the host plant. the host-cell target of v2, however, remains unknown. here we show that v2 interacts directly with slsgs3, the tomato homolog of the arabidopsis sgs3 protein (atsgs3), which is known to be involved in the rna-silencing pathway. slsgs3 genetically complemented an atsgs3 mutation and restored rna silencing, indicating that slsgs3 is i ... | 2008 | 18165314 |
| interaction with host sgs3 is required for suppression of rna silencing by tomato yellow leaf curl virus v2 protein. | the v2 protein of tomato yellow leaf curl geminivirus (tylcv) functions as an rna-silencing suppressor that counteracts the innate immune response of the host plant. the host-cell target of v2, however, remains unknown. here we show that v2 interacts directly with slsgs3, the tomato homolog of the arabidopsis sgs3 protein (atsgs3), which is known to be involved in the rna-silencing pathway. slsgs3 genetically complemented an atsgs3 mutation and restored rna silencing, indicating that slsgs3 is i ... | 2008 | 18165314 |
| strategy for in situ detection of natural transformation-based horizontal gene transfer events. | a strategy is described that enables the in situ detection of natural transformation in acinetobacter baylyi bd413 by the expression of a green fluorescent protein. microscale detection of bacterial transformants growing on plant tissues was shown by fluorescence microscopy and indicated that cultivation-based selection of transformants on antibiotic-containing agar plates underestimates transformation frequencies. | 2008 | 18165369 |
| strategy for in situ detection of natural transformation-based horizontal gene transfer events. | a strategy is described that enables the in situ detection of natural transformation in acinetobacter baylyi bd413 by the expression of a green fluorescent protein. microscale detection of bacterial transformants growing on plant tissues was shown by fluorescence microscopy and indicated that cultivation-based selection of transformants on antibiotic-containing agar plates underestimates transformation frequencies. | 2008 | 18165369 |
| enhancement of stress tolerance in transgenic tobacco plants constitutively expressing atipk2beta, an inositol polyphosphate 6-/3-kinase from arabidopsis thaliana. | inositol phosphates (ips) and their turnover products have been implicated to play important roles in stress signaling in eukaryotic cells. in higher plants genes encoding inositol polyphosphate kinases have been identified previously, but their physiological functions have not been fully resolved. here we expressed arabidopsis inositol polyphosphate 6-/3-kinase (atipk2beta) in two heterologous systems, i.e. the yeast saccharomyces cerevisiae and in tobacco (nicotiana tabacum), and tested the ef ... | 2008 | 18165921 |
| enhancement of stress tolerance in transgenic tobacco plants constitutively expressing atipk2beta, an inositol polyphosphate 6-/3-kinase from arabidopsis thaliana. | inositol phosphates (ips) and their turnover products have been implicated to play important roles in stress signaling in eukaryotic cells. in higher plants genes encoding inositol polyphosphate kinases have been identified previously, but their physiological functions have not been fully resolved. here we expressed arabidopsis inositol polyphosphate 6-/3-kinase (atipk2beta) in two heterologous systems, i.e. the yeast saccharomyces cerevisiae and in tobacco (nicotiana tabacum), and tested the ef ... | 2008 | 18165921 |
| [transformation of full-length gene of mouse/human chimeric antibody against hantaan virus into arabidopsis thaliana]. | to construct the transgenic arabidopsis thaliana containing full-length gene of mouse/human chimeric antibody(3g1mh) against hantaan virus. | 2008 | 18177619 |
| protein subassemblies of the helicobacter pylori cag type iv secretion system revealed by localization and interaction studies. | type iv secretion systems are possibly the most versatile protein transport systems in gram-negative bacteria, with substrates ranging from small proteins to large nucleoprotein complexes. in many cases, such as the cag pathogenicity island of helicobacter pylori, genes encoding components of a type iv secretion system have been identified due to their sequence similarities to prototypical systems such as the virb system of agrobacterium tumefaciens. the cag type iv secretion system contains at ... | 2008 | 18178731 |
| conjugal transfer of the salmonella enterica virulence plasmid in the mouse intestine. | balb/c mice were infected with two salmonella enterica serovar typhimurium strains, one of which lacked the virulence plasmid. transconjugants were found at high frequencies in the mouse feces and at low frequencies in the liver and the spleen, suggesting that mating occurred in the gut. laboratory conditions that mimic those of the small intestine (microaerophilic growth in the presence of 0.3 m nacl) increased the frequency of virulence plasmid transfer. sodium deoxycholate, which is found at ... | 2008 | 18178735 |
| functional differences between heme permeases: serratia marcescens hemtuv permease exhibits a narrower substrate specificity (restricted to heme) than the escherichia coli dppabcdf peptide-heme permease. | serratia marcescens hemtuv genes encoding a potential heme permease were cloned in escherichia coli recombinant mutant fb827 dppf::km(pam 238-hasr). this strain, which expresses hasr, a foreign heme outer membrane receptor, is potentially capable of using heme as an iron source. however, this process is invalidated due to a dppf::km mutation which inactivates the dpp heme/peptide permease responsible for heme, dipeptide, and delta-aminolevulinic (ala) transport through the e. coli inner membrane ... | 2008 | 18178744 |
| the type b phosphatidylinositol-4-phosphate 5-kinase 3 is essential for root hair formation in arabidopsis thaliana. | root hairs are extensions of root epidermal cells and a model system for directional tip growth of plant cells. a previously uncharacterized arabidopsis thaliana phosphatidylinositol-4-phosphate 5-kinase gene (pip5k3) was identified and found to be expressed in the root cortex, epidermal cells, and root hairs. recombinant pip5k3 protein was catalytically active and converted phosphatidylinositol-4-phosphate to phosphatidylinositol-4,5-bisphosphate [ptdins(4,5)p2]. arabidopsis mutant plants homoz ... | 2008 | 18178770 |
| environmental risk assessment of genetically engineered herbicide-tolerant zoysia japonica. | herbicide-tolerant zoysia grass (zoysia japonica steud.) has been generated previously through agrobacterium tumefaciens-mediated transformation. the genetically modified (gm) zoysia grass survived basta spraying and grew to maturity normally while the wild-type (wt) grass stopped growing and died. gm zoysia grass will permit more efficient weed control for various turf grass plantings such as home lawns, golf courses, and parks. we examined the environmental/biodiversity risks of herbicide-tole ... | 2008 | 18178894 |
| agrobacterium-mediated transformation and insertional mutagenesis in colletotrichum acutatum for investigating varied pathogenicity lifestyles. | colletotrichum acutatum is a cosmopolitan pathogen causing economically important diseases known as anthracnose on a wide range of hosts. this fungus exhibits varied pathogenicity lifestyles and the tools essential to understand the molecular mechanisms are still being developed. the transformation methods currently available for this species for gene discovery and functional analysis involve protoplast transformation and are laborious and inefficient. we have developed a protocol for efficient ... | 2008 | 18183501 |
| phytochrome- and gibberellin-mediated regulation of abscisic acid metabolism during germination of photoblastic lettuce seeds. | germination of lettuce (lactuca sativa) 'grand rapids' seeds is regulated by phytochrome. the action of phytochrome includes alterations in the levels of gibberellin (ga) and abscisic acid (aba). to determine the molecular mechanism of phytochrome regulation of aba metabolism, we isolated four lettuce cdnas encoding 9-cis-epoxycarotenoid dioxygenase (biosynthesis; lsnced1-lsnced4) and four cdnas for aba 8'-hydroxylase (catabolism; lsaba8ox1-lsaba8ox4). measurements of aba and its catabolites sho ... | 2008 | 18184730 |
| modulation of the hormone setting by rhodococcus fascians results in ectopic knox activation in arabidopsis. | the biotrophic actinomycete rhodococcus fascians has a profound impact on plant development and a common aspect of the symptomatology is the deformation of infected leaves. in arabidopsis (arabidopsis thaliana), the serrated leaf margins formed upon infection resemble the leaf phenotype of transgenic plants with ectopic expression of knotted-like homeobox (knox) genes. through transcript profiling, we demonstrate that class-i knox genes are transcribed in symptomatic leaves. functional analysis ... | 2008 | 18184732 |
| functional characterization of palax1, a putative auxin permease, in heterologous plant systems. | we have isolated the cdna of the gene palax1 from a wild cherry tree (prunus avium). the gene and its product are highly similar in sequences to both the cdnas and the corresponding protein products of aux/lax-type genes, coding for putative auxin influx carriers. we have prepared and characterized transformed nicotiana tabacum and arabidopsis thaliana plants carrying the gene palax1. we have proved that constitutive overexpression of palax1 is accompanied by changes in the content and distribut ... | 2008 | 18184737 |
| farnesylation directs atipt3 subcellular localization and modulates cytokinin biosynthesis in arabidopsis. | cytokinins regulate cell division and differentiation as well as a number of other processes implicated in plant development. the first step of cytokinin biosynthesis in arabidopsis (arabidopsis thaliana) is catalyzed by adenosine phosphate-isopentenyltransferases (atipt). the enzymes are localized in plastids or the cytoplasm where they utilize the intermediate dimethylallyl-diphosphate from the methylerythritolphosphate or mevalonic acid pathways. however, the regulatory mechanisms linking ati ... | 2008 | 18184738 |
| cytoplasmic targeting of ipac to the bacterial pole directs polar type iii secretion in shigella. | type iii secretion (t3s) systems are largely used by pathogenic gram-negative bacteria to inject multiple effectors into eukaryotic cells. upon cell contact, these bacterial microinjection devices insert two t3s substrates into host cell membranes, forming a so-called 'translocon' that is required for targeting of type iii effectors in the cell cytosol. here, we show that secretion of the translocon component ipac of invasive shigella occurs at the level of one bacterial pole during cell invasio ... | 2008 | 18188151 |
| mutational analysis of deinococcus radiodurans bacteriophytochrome reveals key amino acids necessary for the photochromicity and proton exchange cycle of phytochromes. | the ability of phytochromes (phy) to act as photointerconvertible light switches in plants and microorganisms depends on key interactions between the bilin chromophore and the apoprotein that promote bilin attachment and photointerconversion between the spectrally distinct red light-absorbing pr conformer and far red light-absorbing pfr conformer. using structurally guided site-directed mutagenesis combined with several spectroscopic methods, we examined the roles of conserved amino acids within ... | 2008 | 18192276 |
| subpicosecond midinfrared spectroscopy of the pfr reaction of phytochrome agp1 from agrobacterium tumefaciens. | phytochromes are light-sensing pigments found in plants and bacteria. for the first time, the p(fr) photoreaction of a phytochrome has been subject to ultrafast infrared vibrational spectroscopy. three time constants of 0.3 ps, 1.3 ps, and 4.0 ps were derived from the kinetics of structurally specific marker bands of the biliverdin chromophore of agp1-bv from agrobacterium tumefaciens after excitation at 765 nm. vis-pump-vis-probe experiments yield time constants of 0.44 ps and 3.3 ps for the un ... | 2008 | 18192363 |
| regulation of type iv secretion apparatus genes during ehrlichia chaffeensis intracellular development by a previously unidentified protein. | the type iv secretion (t4s) system is critical for the virulence of several pathogens. in the rickettsial pathogen ehrlichia chaffeensis, the virbd genes are split into two operons, the virb3-virb6 (preceded by sodb) and virb8-vird4 operons. between these two operons, there are duplications of virb4, virb8, and virb9. in this study we found that transcription of all five loci was downregulated prior to the release of e. chaffeensis from host thp-1 cells and was upregulated at the initiation of e ... | 2008 | 18192398 |
| phylogenetic characterization and prevalence of "spirobacillus cienkowskii," a red-pigmented, spiral-shaped bacterial pathogen of freshwater daphnia species. | microscopic examination of the hemolymph from diseased daphniids in 17 lakes in southwestern michigan and five rock pools in southern finland revealed the presence of tightly coiled bacteria that bore striking similarities to the drawings of a morphologically unique pathogen, "spirobacillus cienkowskii," first described by elya metchnikoff more than 100 years ago. the uncultivated microbe was identified as a deeply branching member of the deltaproteobacteria through phylogenetic analyses of two ... | 2008 | 18192404 |
| quantification of the detrimental effect of a single primer-template mismatch by real-time pcr using the 16s rrna gene as an example. | we investigated the effects of internal primer-template mismatches on the efficiency of pcr amplification using the 16s rrna gene as the model template dna. we observed that the presence of a single mismatch in the second half of the primer extension sequence can result in an underestimation of up to 1,000-fold of the gene copy number, depending on the primer and position of the mismatch. | 2008 | 18192413 |
| a rhodococcus qsda-encoded enzyme defines a novel class of large-spectrum quorum-quenching lactonases. | a gene involved in n-acyl homoserine lactone (n-ahsl) degradation was identified by screening a genomic library of rhodococcus erythropolis strain w2. this gene, named qsda (for quorum-sensing signal degradation), encodes an n-ahsl lactonase unrelated to the two previously characterized n-ahsl-degrading enzymes, i.e., the lactonase aiia and the amidohydrolase aiid. qsda is related to phosphotriesterases and constitutes the reference of a novel class of n-ahsl degradation enzymes. it confers the ... | 2008 | 18192419 |
| activation of the indole-3-acetic acid-amido synthetase gh3-8 suppresses expansin expression and promotes salicylate- and jasmonate-independent basal immunity in rice. | new evidence suggests a role for the plant growth hormone auxin in pathogenesis and disease resistance. bacterial infection induces the accumulation of indole-3-acetic acid (iaa), the major type of auxin, in rice (oryza sativa). iaa induces the expression of expansins, proteins that loosen the cell wall. loosening the cell wall is key for plant growth but may also make the plant vulnerable to biotic intruders. here, we report that rice gh3-8, an auxin-responsive gene functioning in auxin-depende ... | 2008 | 18192436 |
| recognition of the hyaloperonospora parasitica effector atr13 triggers resistance against oomycete, bacterial, and viral pathogens. | phytopathogenic oomycetes cause some of the most devastating diseases affecting agricultural crops. hyaloperonospora parasitica is a native oomycete pathogen of arabidopsis and is related to other oomycete phytopathogens that include several species of phytophthora, including the causal agent of potato late blight. recently, four oomycete effector genes have been isolated, and several oomycete genomes have been sequenced. we have developed an efficient and genetically amenable system to test put ... | 2008 | 18198274 |
| class viii myosins are required for plasmodesmatal localization of a closterovirus hsp70 homolog. | the hsp70 homolog (hsp70h) of beet yellows virus (byv) functions in virion assembly and cell-to-cell movement and is autonomously targeted to plasmodesmata in association with the actomyosin motility system (a. i. prokhnevsky, v. v. peremyslov, and v. v. dolja, j. virol. 79:14421-14428, 2005). myosins are a diverse category of molecular motors that possess a motor domain and a tail domain involved in cargo binding. plants have two classes of myosins, viii and xi, whose specific functions are poo ... | 2008 | 18199648 |
| bacterial nonhomologous end joining ligases preferentially seal breaks with a 3'-oh monoribonucleotide. | many bacterial species have a nonhomologous end joining system of dna repair driven by dedicated dna ligases (ligd and ligc). ligd is a multifunctional enzyme composed of a ligase domain fused to two other catalytic modules: a polymerase that preferentially adds ribonucleotides to double-strand break ends and a phosphoesterase that trims 3'-oligoribonucleotide tracts until only a single 3'-ribonucleotide remains. ligd and ligc have a feeble capacity to seal 3'-oh/5'-po(4) dna nicks. here, we rep ... | 2008 | 18203718 |
| induction and loss of ti plasmid conjugative competence in response to the acyl-homoserine lactone quorum-sensing signal. | conjugative transfer of the ti plasmids of agrobacterium tumefaciens is controlled by a quorum-sensing system composed of trar and its signal n-(3-oxo-octanoyl)-l-homoserine lactone. this system is, in turn, controlled by the conjugative opines produced by crown gall tumors induced on plants by the bacteria. using nonpolar trai mutants, we examined the kinetics of induction of conjugative transfer in response to exogenous acyl-homoserine lactone. in the absence of the antiactivator tram, onset o ... | 2008 | 18203831 |
| diversity and quorum-sensing signal production of proteobacteria associated with marine sponges. | marine sponges are hosts to diverse and dense bacterial communities and thus provide a potential environment for quorum sensing. quorum sensing, a key factor in cell-cell communication and bacterial colonization of higher animals, might be involved in the symbiotic interactions between bacteria and their sponge hosts. given that marine proteobacteria are known to produce n-acyl homoserine lactone (ahl) signal molecules, we tested the production of ahls by alpha- and gammaproteobacteria isolated ... | 2008 | 18211268 |
| detection of pseudomonas aeruginosa quorum sensing signals in an infected ischemic wound: an experimental study in rats. | quorum sensing is a cell-to-cell communication that occurs via autoinducers, regulating a number of bacterial virulence factors including the opportunistic wound pathogen pseudomonas aeruginosa, which uses the n-(3-oxododecanoyl)-homoserine lactone as one of the two main autoinducers; however, little is known about its role in chronic wound infection. this study was designed to quantify this autoinducer from p. aeruginosa-infected wounds with the aim of examining the possible use of autoinducers ... | 2008 | 18211577 |
| a modified gateway cloning strategy for overexpressing tagged proteins in plants. | abstract: | 2008 | 18211686 |
| dyskerin is a component of the arabidopsis telomerase rnp required for telomere maintenance. | dyskerin binds the h/aca box of human telomerase rna and is a core telomerase subunit required for rnp biogenesis and enzyme function in vivo. missense mutations in dyskerin result in dyskeratosis congenita, a complex syndrome characterized by bone marrow failure, telomerase enzyme deficiency, and progressive telomere shortening. here we demonstrate that dyskerin also contributes to telomere maintenance in arabidopsis thaliana. we report that both atnap57, the arabidopsis dyskerin homolog, and a ... | 2008 | 18212040 |
| crystal structure of glycerophosphodiester phosphodiesterase (gdpd) from thermoanaerobacter tengcongensis, a metal ion-dependent enzyme: insight into the catalytic mechanism. | glycerophosphodiester phosphodiesterase (gdpd; ec 3.1.4.46) catalyzes the hydrolysis of a glycerophosphodiester to an alcohol and glycerol 3-phosphate in glycerol metabolism. it has an important role in the synthesis of a variety of products that participate in many biochemical pathways. we report the crystal structure of the thermoanaerobacter tengcongensis gdpd (ttgdpd) at 1.91 a resolution, with a calcium ion and glycerol as a substrate mimic coordinated at this calcium ion (pdb entry 2pz0). ... | 2008 | 18214974 |
| antiviral rna silencing is restricted to the marginal region of the dark green tissue in the mosaic leaves of tomato mosaic virus-infected tobacco plants. | mosaic is a common disease symptom caused by virus infection in plants. mosaic leaves of tomato mosaic virus (tomv)-infected tobacco plants consist of yellow-green and dark green tissues that contain large and small numbers of virions, respectively. although the involvement of rna silencing in mosaic development has been suggested, its role in the process that results in an uneven distribution of the virus is unknown. here, we investigated whether and where tomv-directed rna silencing was establ ... | 2008 | 18216118 |
| [antimicrobial activity of calendula l. plants]. | the sap of different organs of genus calendula plant species has been studied for antimicrobial activity. the sap of racemes demonstrated the most expressed antimicrobial effect while that of the roots - the least one. calendula species inhibited all tested pathogenic microorganisms, especially pseudomonas syringae, p. fluorescens, xanthomonas campestris, agrobacterium tumefaciens. calendula suffruticosa was the most active to all investigated microorganisms. | 2007 | 18217350 |
| myb72 is required in early signaling steps of rhizobacteria-induced systemic resistance in arabidopsis. | colonization of arabidopsis thaliana roots by nonpathogenic pseudomonas fluorescens wcs417r bacteria triggers a jasmonate/ethylene-dependent induced systemic resistance (isr) that is effective against a broad range of pathogens. microarray analysis revealed that the r2r3-myb-like transcription factor gene myb72 is specifically activated in the roots upon colonization by wcs417r. here, we show that t-dna knockout mutants myb72-1 and myb72-2 are incapable of mounting isr against the pathogens pseu ... | 2008 | 18218967 |
| cloning and characterization of naringenin 8-prenyltransferase, a flavonoid-specific prenyltransferase of sophora flavescens. | prenylated flavonoids are natural compounds that often represent the active components in various medicinal plants and exhibit beneficial effects on human health. prenylated flavonoids are hybrid products composed of a flavonoid core mainly attached to either 5-carbon (dimethylallyl) or 10-carbon (geranyl) prenyl groups derived from isoprenoid (terpenoid) metabolism, and the prenyl groups are crucial for their biological activity. prenylation reactions in vivo are crucial coupling processes of t ... | 2008 | 18218974 |
| characterization of arabidopsis and rice dwd proteins and their roles as substrate receptors for cul4-ring e3 ubiquitin ligases. | a subset of wd40 proteins that contain a dwd motif (for ddb1 binding wd40) is reported to act as substrate receptors for ddb1-cul4-roc1 (for damaged dna binding 1-cullin 4-regulator of cullins 1) based e3 ubiquitin ligases in humans. here, we report 85 arabidopsis thaliana and 78 rice (oryza sativa) proteins containing the conserved 16-amino acid dwd motif. we show by yeast two-hybrid and in vivo coimmunoprecipitation that 11 arabidopsis dwd proteins directly interact with ddb1 and thus may serv ... | 2008 | 18223036 |
| a plasma membrane-anchored fluorescent protein fusion illuminates sieve element plasma membranes in arabidopsis and tobacco. | rapid acquisition of quantitative anatomical data from the sieve tubes of angiosperm phloem has been confounded by their small size, their distance from organ surfaces, and the time-consuming nature of traditional methods, such as transmission electron microscopy. to improve access to these cells, for which good anatomical data are critical, a monomeric yellow fluorescent protein (mcitrine) was n-terminally fused to a small (approximately 6 kd) membrane protein (atrci2a) and stably expressed in ... | 2008 | 18223149 |
| mining the moraxella catarrhalis genome: identification of potential vaccine antigens expressed during human infection. | moraxella catarrhalis is an important cause of respiratory infections in adults and otitis media in children. developing an effective vaccine would reduce the morbidity, mortality, and costs associated with such infections. an unfinished genome sequence of a strain of m. catarrhalis available in the genbank database was analyzed, and open reading frames predicted to encode potential vaccine candidates were identified. three genes encoding proteins having molecular masses of approximately 22, 75, ... | 2008 | 18227159 |
| the sho1 sensor regulates growth, morphology, and oxidant adaptation in aspergillus fumigatus but is not essential for development of invasive pulmonary aspergillosis. | aspergillus fumigatus is an important opportunistic fungal pathogen. this organism must be able to adapt to stress changes in the microenvironment during host invasion and systemic spread. the high-osmolarity-glycerol (hog) mitogen-activated protein kinase (hog-mapk) signaling pathway plays an important role in regulating morphology, growth, and adaptation to stress and virulence in a number of fungal pathogens. the sho1 adaptor protein is one important element of the two upstream branches of th ... | 2008 | 18227163 |
| identification of protein secretion systems and novel secreted proteins in rhizobium leguminosarum bv. viciae. | proteins secreted by bacteria play an important role in infection of eukaryotic hosts. rhizobia infect the roots of leguminous plants and establish a mutually beneficial symbiosis. proteins secreted during the infection process by some rhizobial strains can influence infection and modify the plant defence signalling pathways. the aim of this study was to systematically analyse protein secretion in the recently sequenced strain rhizobium leguminosarum bv. viciae 3841. | 2008 | 18230162 |
| the funnel approach to the precrystallization production of membrane proteins. | challenges in the production of integral membrane proteins for structural studies include low expression levels, incorrect membrane insertion, aggregation and instability. in this report, we describe a "funnel approach" to overcoming these difficulties and demonstrate its efficacy in a case study of 36 prokaryotic p-type transporters. a diverse ensemble of modified constructs is generated and tested for expression in escherichia coli, membrane localization, detergent extraction, and homogeneity. ... | 2008 | 18241890 |
| molecular variation of satellite dna beta molecules associated with malvastrum yellow vein virus and their role in pathogenicity. | previous studies have found that the diversity of begomovirus-associated dna beta satellites is related to host and geographical origin. in this study, we have cloned and sequenced 20 different isolates of dna beta molecules associated with malvastrum yellow vein virus (myvv) isolated from malvastrum coromandelianum plants in different geographical locations of yunnan province, china. analyses of their molecular variation indicate that the satellites are clustered together according to their geo ... | 2008 | 18245261 |
| control of acetic acid fermentation by quorum sensing via n-acylhomoserine lactones in gluconacetobacter intermedius. | a number of gram-negative bacteria regulate gene expression in a cell density-dependent manner by quorum sensing via n-acylhomoserine lactones (ahls). gluconacetobacter intermedius nci1051, a gram-negative acetic acid bacterium, produces three different ahls, n-decanoyl-l-homoserine lactone, n-dodecanoyl-l-homoserine lactone, and an n-dodecanoyl-l-homoserine lactone with a single unsaturated bond in its acyl chain, as determined by liquid chromatography-tandem mass spectrometry. two genes encodi ... | 2008 | 18245283 |
| hypericum perforatum plant cells reduce agrobacterium viability during co-cultivation. | plant recalcitrance is the major barrier in developing agrobacterium-mediated transformation protocols for several important plant species. despite the substantial knowledge of t-dna transfer process, very little is known about the factors leading to the plant recalcitrance. here, we analyzed the basis of hypericum perforatum l. (hp) recalcitrance to agrobacterium-mediated transformation using cell suspension culture. when challenged with agrobacterium, hp cells swiftly produced an intense oxida ... | 2008 | 18247048 |
| characteristic expression of twelve rice pr1 family genes in response to pathogen infection, wounding, and defense-related signal compounds (121/180). | pathogenesis-related (pr) proteins have been used as markers of plant defense responses, and are classified into 17 families. however, precise information on the majority members in specific pr families is still limited. we were interested in the individual characteristics of rice pr1 family genes, and selected 12 putatively active genes using rice genome databases for expressed genes. all were upregulated upon compatible and/or incompatible rice-blast fungus interactions; three were upregulated ... | 2008 | 18247056 |
| agrobacterium tumefaciens -mediated transformation of the zygomycete fungus backusella lamprospora. | the agrobacterium -mediated transformation was adapted to backusella lamprospora, a zygomycete fungus closely related to mucor. the transforming plasmid contained the hygromycin b resistance (hph) and the green fluorescent protein (gfp) genes under the control of the regulator regions of the mucor circinelloides gpd1 gene. the presence of the hph and gfp genes in the transformants was detected by pcr. the introduced genes could also be amplified directly from the spores of the transformants. the ... | 2008 | 18247397 |
| ostdl1a binds to the lrr domain of rice receptor kinase msp1, and is required to limit sporocyte numbers. | hybrids lose heterotic yield advantage when multiplied sexually via meiosis. a potential alternative breeding system for hybrids is apospory, where female gametes develop without meiosis. common among grasses, apospory begins in the nucellus, where aposporous initials (ais) appear near the sexual megaspore mother cell (memc). the cellular origin of ais is obscure, but one possibility, suggested by the mac1 and msp1 mutants of maize and rice, is that ais are apomeiotic derivatives of the addition ... | 2008 | 18248596 |
| t-dna binary vectors and systems. | | 2008 | 18250230 |
| [factors influencing agrobacterium-mediated cotyledonary-node transformation of soybean (glycine max l.)]. | using agrobacterium tumefaciens strain eha105 carrying binary vector p1301, which containing the gus and hpt genes, a highly efficient transformation system was developed based on the study of factors influencing the agrobacterium-mediated cotyledonary-node transformation of soybean. the results demonstrated the additions of acetosyringone (200 micromol/l) and ascorbatic acid (50 mg/l) in both infection medium and co-cultivation medium resulted in a significant increase in the transformation eff ... | 2007 | 18254332 |
| characterization of the histidine-containing phosphotransfer protein b-mediated multistep phosphorelay system in pseudomonas aeruginosa pao1. | certain bacterial two-component sensor kinases possess a histidine-containing phosphotransfer (hpt) domain to carry out a multistep phosphotransferring reaction to a cognate response regulator. pseudomonas aeruginosa pao1 contains three genes that encode proteins with an hpt domain but lack a kinase domain. to identify the sensor kinase coupled to these hpt proteins, a phosphorelay profiling assay was performed. among the 12 recombinant orphan sensor kinases tested, 4 of these sensors (pa1611, p ... | 2008 | 18256026 |
| agroinfiltration of grapevine leaves for fast transient assays of gene expression and for long-term production of stable transformed cells. | agrobacterium-mediated transient assays for the analysis of gene function are used as alternatives to genetic complementation and stable plant transformation. although such assays are routinely performed in several plant species, they have not yet been successfully applied to grapevines. we explored genetic background diversity of grapevine cultivars and performed agroinfiltration into in vitro cultured plants. by combining different genotypes and physiological conditions, we developed a protoco ... | 2008 | 18256839 |
| identification of negative cis-acting elements in response to copper in the chloroplastic iron superoxide dismutase gene of the moss barbula unguiculata. | superoxide dismutases (sods) are ubiquitous metalloenzymes that catalyze the dismutation of superoxide radicals. chloroplasts have two isozymes, copper/zinc sod (cu/znsod) and iron sod (fesod), encoded by nuclear genes. because bryophytes are considered as the earliest land plants, they are one of the most interesting plant models for adaptation against oxidative stress. in a previous study, we found that the fesod gene was expressed under cu-deficient conditions and repressed under high-cu-supp ... | 2008 | 18258690 |
| redirection of flavonoid biosynthesis through the down-regulation of an anthocyanidin glucosyltransferase in ripening strawberry fruit. | strawberry (fragaria x ananassa) fruit contains several anthocyanins that give the ripe fruits their attractive red color. the enzyme that catalyzes the formation of the first stable intermediate in the anthocyanin pathway is anthocyanidin-3-o-glucosyltransferase. a putative glycosyltransferase sequence (fagt1) was cloned from a strawberry fruit cdna library and the recombinant fagt1 transferred udp-glucose to anthocyanidins and, to a lesser extent, flavonols, generating the respective 3-o-gluco ... | 2008 | 18258692 |
| structural insight into the reaction mechanism and evolution of cytokinin biosynthesis. | the phytohormone cytokinin regulates plant growth and development. this hormone is also synthesized by some phytopathogenic bacteria, such as agrobacterium tumefaciens, and is as a key factor in the formation of plant tumors. the rate-limiting step of cytokinin biosynthesis is catalyzed by adenosine phosphate-isopentenyltransferase (ipt). agrobacterium ipt has a unique substrate specificity that enables it to increase trans-zeatin production by recruiting a metabolic intermediate of the host pla ... | 2008 | 18258747 |
| secretome analysis uncovers an hcp-family protein secreted via a type vi secretion system in agrobacterium tumefaciens. | agrobacterium tumefaciens is a plant-pathogenic bacterium capable of secreting several virulence factors into extracellular space or the host cell. in this study, we used shotgun proteomics analysis to investigate the secretome of a. tumefaciens, which resulted in identification of 12 proteins, including 1 known secretory protein (virb1*) and 11 potential secretory proteins. interestingly, one unknown protein, which we designated hemolysin-coregulated protein (hcp), is a predicted soluble protei ... | 2008 | 18263727 |
| the hopz family of pseudomonas syringae type iii effectors require myristoylation for virulence and avirulence functions in arabidopsis thaliana. | pseudomonas syringae utilizes the type iii secretion system to translocate effector proteins into plant cells, where they can contribute to the pathogen's ability to infect and cause disease. recognition of these effectors by resistance proteins induces defense responses that typically include a programmed cell death reaction called the hypersensitive response. the yopj/hopz family of type iii effector proteins is a common family of effector proteins found in animal- and plant-pathogenic bacteri ... | 2008 | 18263728 |
| a novel wrky transcription factor is required for induction of pr-1a gene expression by salicylic acid and bacterial elicitors. | pr-1a is a salicylic acid-inducible defense gene of tobacco (nicotiana tabacum). one-hybrid screens identified a novel tobacco wrky transcription factor (ntwrky12) with specific binding sites in the pr-1a promoter at positions -564 (box wk(1)) and -859 (box wk(2)). ntwrky12 belongs to the class of transcription factors in which the wrky sequence is followed by a gkk rather than a gqk sequence. the binding sequence of ntwrky12 (wk box ttttccac) deviated significantly from the consensus sequence ( ... | 2008 | 18263781 |
| senescence-induced ectopic expression of the a. tumefaciens ipt gene in wheat delays leaf senescence, increases cytokinin content, nitrate influx, and nitrate reductase activity, but does not affect grain yield. | the manipulation of cytokinin levels by senescence-regulated expression of the agrobacterium tumefaciens ipt gene through its control by the arabidopsis sag12 (senescence-associated gene 12) promoter is an efficient tool for the prolongation of leaf photosynthetic activity which potentially can affect plant productivity. in the present study, the efficiency of this approach was tested on wheat (triticum aestivum l.)-a monocarpic plant characterized by a fast switch from vegetative to reproductiv ... | 2008 | 18267946 |
| tobacco rattle virus 16-kilodalton protein encodes a suppressor of rna silencing that allows transient viral entry in meristems. | rna silencing is a host defense mechanism that limits the accumulation and spread of viruses in infected plants. correspondingly, plant viruses encode suppressors of silencing. in the positive-strand rna virus tobacco rattle virus (trv), the suppressor of silencing is a 16-kda (16k) protein encoded by rna1. the suppressor action of the 16k protein is transient and weaker than that of the p19 suppressor, encoded by tomato bushy stunt virus. mutant trv that does not produce its suppressor, unlike ... | 2008 | 18272576 |
| trar auto-inducer enhances protein backbone fluctuations in dna binding domain. | the bacterium agrobacterium tumefaciens mediates quorum sensing via trar, a n-3-oxo-octanoyl-l-homoserine lactone (oohl) signaling transcription factor. trar consists of an n-terminal per-arnt-sim domain (pas-domain) containing oohl and a c-terminal helix-turn-helix motif (htf-motif) binding dna, thus comprising a complete signaling pathway. using molecular dynamics, we investigate the influence of oohl on the dynamics of the protein. the oohl binding pocket is in contact with water, leading to ... | 2008 | 18275856 |
| isolation and characterization of an autoinducer synthase from acinetobacter baumannii. | the opportunistic human pathogen acinetobacter baumannii strain m2 was found to produce distinct acyl-homoserine lactone (ahl) signals based on the use of an agrobacterium tumefaciens trag-lacz biosensor. an a. baumannii gene, designated abai, was cloned and directed ahl production in recombinant escherichia coli. the abai protein was similar to members of the luxi family of autoinducer synthases and was predicted to be the only autoinducer synthase encoded by a. baumannii. the primary ahl signa ... | 2008 | 18281398 |
| the pathways and outcomes of mycobacterial nhej depend on the structure of the broken dna ends. | mycobacteria can repair dna double-strand breaks (dsbs) via a nonhomologous end-joining (nhej) system that includes a dedicated dna ligase (ligd) and the dna end-binding protein ku. here we exploit an improved plasmid-based nhej assay and a collection of mycobacterium smegmatis strains bearing deletions or mutations in ku or the dna ligases to interrogate the contributions of ligd's three catalytic activities (polymerase, ligase, and 3' phosphoesterase) and structural domains (pol, lig, and pe) ... | 2008 | 18281464 |
| isolation of a strong arabidopsis guard cell promoter and its potential as a research tool. | abstract: | 2008 | 18284694 |
| examining the specific contributions of individual arabidopsis metallothioneins to copper distribution and metal tolerance. | metallothioneins (mts) are small cysteine-rich proteins found in various eukaryotes. plant mts are classified into four types based on the arrangement of cysteine residues. to determine whether all four types of plant mts function as metal chelators, six arabidopsis (arabidopsis thaliana) mts (mt1a, mt2a, mt2b, mt3, mt4a, and mt4b) were expressed in the copper (cu)- and zinc (zn)-sensitive yeast mutants, deltacup1 and deltazrc1 deltacot1, respectively. all four types of arabidopsis mts provided ... | 2008 | 18287486 |
| recent advances in medicago truncatula genomics. | legume rotation has allowed a consistent increase in crop yield and consequently in human population since the antiquity. legumes will also be instrumental in our ability to maintain the sustainability of our agriculture while facing the challenges of increasing food and biofuel demand. medicago truncatula and lotus japonicus have emerged during the last decade as two major model systems for legume biology. initially developed to dissect plant-microbe symbiotic interactions and especially legume ... | 2008 | 18288239 |
| recent advances in medicago truncatula genomics. | legume rotation has allowed a consistent increase in crop yield and consequently in human population since the antiquity. legumes will also be instrumental in our ability to maintain the sustainability of our agriculture while facing the challenges of increasing food and biofuel demand. medicago truncatula and lotus japonicus have emerged during the last decade as two major model systems for legume biology. initially developed to dissect plant-microbe symbiotic interactions and especially legume ... | 2008 | 18288239 |
| rhizobium radiobacter as an opportunistic pathogen in central venous catheter-associated bloodstream infection: case report and review. | rhizobium radiobacter is an uncommon opportunistic pathogen present in soil. it has been particularly associated with indwelling intravascular devices in immunocompromised patients. in this report, we summarise the case of a patient with multiple myeloma who developed r. radiobacter bacteraemia during autologous stem cell leucopheresis. retrospective investigation revealed exposure to soil after central venous catheter placement for chemotherapy and leucopheresis access. this is the first report ... | 2008 | 18289729 |
| the highly repetitive region of the helicobacter pylori cagy protein comprises tandem arrays of an alpha-helical repeat module. | the cag-pathogenicity-island-encoded type iv secretion system of helicobacter pylori functions to translocate the effector protein caga directly through the plasma membrane of gastric epithelial cells. similar to other secretion systems, the cag type iv secretion system elaborates a surface filament structure, which is unusually sheathed by the large cag-pathogenicity-island-encoded protein cagy. cagy is distinguished by unusual amino acid composition and extensive repetitive sequence organised ... | 2008 | 18295231 |
| identification of a novel adenine nucleotide transporter in the endoplasmic reticulum of arabidopsis. | many metabolic reactions in the endoplasmic reticulum (er) require high levels of energy in the form of atp, which is important for cell viability. here, we report on an adenine nucleotide transporter residing in the er membranes of arabidopsis thaliana (er-ant1). functional integration of er-ant1 in the cytoplasmic membrane of intact escherichia coli cells reveals a high specificity for an atp/adp antiport. immunodetection in transgenic er-ant1-c-myc-tag arabidopsis plants and immunogold labeli ... | 2008 | 18296626 |
| origin and evolution of gala-lrr, a new member of the cc-lrr subfamily: from plants to bacteria? | the phytopathogenic bacterium ralstonia solanacearum encodes type iii effectors, called gala proteins, which contain f-box and lrr domains. the gala lrrs do not perfectly fit any of the previously described lrr subfamilies. by applying protein sequence analysis and structural prediction, we clarify this ambiguous case of lrr classification and assign gala-lrrs to cc-lrr subfamily. we demonstrate that side-by-side packing of lrrs in the 3d structures may control the limits of repeat variability w ... | 2008 | 18301771 |
| agrobacterium tumefaciens-mediated transformation of taro (colocasia esculenta (l.) schott) with a rice chitinase gene for improved tolerance to a fungal pathogen sclerotium rolfsii. | taro (colocasia esculenta) is one of the most important crops in the pacific islands, however, taro yields have been declining in hawaii over the past 30 years partly due to diseases caused by oomycete and fungal pathogens. in this study, an efficient agrobacterium tumefaciens-mediated transformation method for taro is first reported. in total, approximately 200 pieces (8 g) of embryogenic calluses were infected with the super-virulent a. tumefaciens strain eha105 harboring the plant transformat ... | 2008 | 18301900 |
| vire2: a unique ssdna-compacting molecular machine. | the translocation of single-stranded dna (ssdna) across membranes of two cells is a fundamental biological process occurring in both bacterial conjugation and agrobacterium pathogenesis. whereas bacterial conjugation spreads antibiotic resistance, agrobacterium facilitates efficient interkingdom transfer of ssdna from its cytoplasm to the host plant cell nucleus. these processes rely on the type iv secretion system (t4ss), an active multiprotein channel spanning the bacterial inner and outer mem ... | 2008 | 18303950 |
| rna-interference in rice against rice tungro bacilliform virus results in its decreased accumulation in inoculated rice plants. | rice tungro is a viral disease seriously affecting rice production in south and southeast asia. tungro is caused by the simultaneous infection in rice of rice tungro bacilliform virus (rtbv), a double-stranded dna virus and rice tungro spherical virus (rtsv), a single-stranded rna virus. to apply the concept of rna-interference (rnai) for the control of rtbv infection, transgenic rice plants expressing dna encoding orf iv of rtbv, both in sense as well as in anti-sense orientation, resulting in ... | 2008 | 18306054 |
| atmrp6/atabcc6, an atp-binding cassette transporter gene expressed during early steps of seedling development and up-regulated by cadmium in arabidopsis thaliana. | abc proteins constitute one of the largest families of transporters found in all living organisms. in arabidopsis thaliana, 120 genes encoding abc transporters have been identified. here, the characterization of one member of the mrp subclass, atmrp6, is described. | 2008 | 18307782 |
| agrobacterium-mediated transformation of the endophytic fungus acremonium implicatum associated with brachiaria grasses. | acremonium implicatum is a seed-transmitted endophytic fungus that forms symbiotic associations with the economically significant tropical forage grasses, brachiaria species. to take advantage of the endophyte's plant protective properties, we developed an efficient agrobacterium-mediated transformation system for acremonium implicatum, using green fluorescent protein (gfp) expression and vector psk1019 (trpc promoter) or pcambia1300 (camv35s promoter). we found that transformation efficiency do ... | 2008 | 18308527 |
| agrobacterium tumefaciens-mediated transformation in colletotrichum falcatum and c. acutatum. | agrobacterium tumefaciens-mediated transformation (atmt) is becoming an effective system as an insertional mutagenesis tool in filamentous fungi. we developed and optimized atmt for two colletotrichum species, c. falcatum and c. acutatum, which are the causal agents of sugarcane red rot and pepper anthracnose, respectively. a. tumefaciens strain sk1044, carrying a hygromycin phosphotransferase gene (hph) and a green fluorescent protein (gfp) gene, was used to transform the conidia of these two c ... | 2008 | 18309266 |
| biochemical and phylogenetic characterization of a novel diaminopimelate biosynthesis pathway in prokaryotes identifies a diverged form of ll-diaminopimelate aminotransferase. | a variant of the diaminopimelate (dap)-lysine biosynthesis pathway uses an ll-dap aminotransferase (dapl, ec 2.6.1.83) to catalyze the direct conversion of l-2,3,4,5-tetrahydrodipicolinate to ll-dap. comparative genomic analysis and experimental verification of dapl candidates revealed the existence of two diverged forms of dapl (dapl1 and dapl2). dapl orthologs were identified in eubacteria and archaea. in some species the corresponding dapl gene was found to lie in genomic contiguity with othe ... | 2008 | 18310350 |
| 1-aminocyclopropane-1-carboxylate deaminase enhances agrobacterium tumefaciens-mediated gene transfer into plant cells. | agrobacterium-mediated gene transfer is widely used for plant molecular genetics, and efficient techniques are required. recent studies show that ethylene inhibits the gene transfer. to suppress ethylene evolution, we introduced 1-aminocyclopropane-1-carboxylate (acc) deaminase into agrobacterium tumefaciens. the acc deaminase enhanced a. tumefaciens-mediated gene transfer into plants. | 2008 | 18310418 |
| polysaccharides cellulose, poly-beta-1,6-n-acetyl-d-glucosamine, and colanic acid are required for optimal binding of escherichia coli o157:h7 strains to alfalfa sprouts and k-12 strains to plastic but not for binding to epithelial cells. | when escherichia coli o157:h7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. in contrast, laboratory k-12 strains of e. coli do not bind to sprouts under similar conditions. the roles of e. coli o157:h7 lipopolysaccharide (lps), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. an lps mutant had no effect on the binding of the pathogenic strain. cellulose synthase mutants showed a significant reduction in bindi ... | 2008 | 18310435 |
| the vibrio cholerae mrp system: cation/proton antiport properties and enhancement of bile salt resistance in a heterologous host. | the mrp operon from vibrio cholerae encoding a putative multisubunit na(+)/h(+) antiporter was cloned and functionally expressed in the antiporter-deficient strain of escherichia coli ep432. cells of ep432 expressing vc-mrp exhibited resistance to na(+) and li(+) as well as to natural bile salts such as sodium cholate and taurocholate. when assayed in everted membrane vesicles of the e. coli ep432 host, vc-mrp had sufficiently high antiport activity to facilitate the first extensive analysis of ... | 2009 | 18311075 |
| the vibrio cholerae mrp system: cation/proton antiport properties and enhancement of bile salt resistance in a heterologous host. | the mrp operon from vibrio cholerae encoding a putative multisubunit na(+)/h(+) antiporter was cloned and functionally expressed in the antiporter-deficient strain of escherichia coli ep432. cells of ep432 expressing vc-mrp exhibited resistance to na(+) and li(+) as well as to natural bile salts such as sodium cholate and taurocholate. when assayed in everted membrane vesicles of the e. coli ep432 host, vc-mrp had sufficiently high antiport activity to facilitate the first extensive analysis of ... | 2009 | 18311075 |
| transcription and activities of nox reductases in agrobacterium tumefaciens: the influence of nitrate, nitrite and oxygen availability. | the ability of agrobacetrium tumefaciens to perform balanced transitions from aerobic to anaerobic respiration was studied by monitoring oxygen depletion, transcription of nirk and norb, and the concentrations of nitrite, nitric oxide (no) and nitrous oxide in stirred batch cultures with different initial oxygen, nitrate or nitrite concentrations. nitrate concentrations (0.2-2 mm) did not affect oxygen depletion, nor the oxygen concentration at which denitrification was initiated (1-2 microm). n ... | 2008 | 18312398 |
| functional adaptation of a plant receptor-kinase paved the way for the evolution of intracellular root symbioses with bacteria. | nitrogen-fixing root nodule symbioses (rns) occur in two major forms-actinorhiza and legume-rhizobium symbiosis-which differ in bacterial partner, intracellular infection pattern, and morphogenesis. the phylogenetic restriction of nodulation to eurosid angiosperms indicates a common and recent evolutionary invention, but the molecular steps involved are still obscure. in legumes, at least seven genes-including the symbiosis receptor-kinase gene symrk-are essential for the interaction with rhizob ... | 2008 | 18318603 |
| expression of a synthetic cry1ec gene for resistance against spodoptera litura in transgenic peanut (arachis hypogaea l.). | the tobacco cutworm (spodoptera litura) is a polyphagous foliage insect and a major pest on peanut (arachis hypogaea l.). s. litura is susceptible to the chimeric delta-endotoxin cry1ec reported earlier. de-embryonated cotyledon explants of peanut were transformed using agrobacterium tumefaciens strain eha101 harboring a synthetic cry1ec gene driven by the camv 35s promoter. transgenic plants of peanut with a single copy insertion of cry1ec were selected in the t(0) generation by southern blot h ... | 2008 | 18320194 |