| arabidopsis decapping 5 is required for mrna decapping, p-body formation, and translational repression during postembryonic development. | eukaryotic processing bodies (p-bodies) are implicated in mrna storage and mrna decapping. we previously found that a decapping complex comprising decapping 1 (dcp1), dcp2, and varicose in arabidopsis thaliana is essential for postembryonic development, but the underlying mechanism is poorly understood. here, we characterized arabidopsis dcp5, a homolog of human rna-associated protein 55, as an additional p-body constituent. dcp5 associates with dcp1 and dcp2 and is required for mrna decapping i ... | 2009 | 19855049 |
| arabidopsis trithorax-related7 is required for methylation of lysine 4 of histone h3 and for transcriptional activation of flowering locus c. | in the winter-annual accessions of arabidopsis thaliana, presence of an active allele of frigida (fri) elevates expression of flowering locus c (flc), a repressor of flowering, and thus confers a vernalization requirement. flc activation by fri involves methylation of lys 4 of histone h3 (h3k4) at flc chromatin. many multicellular organisms that have been examined contain two classes of h3k4 methylases, a yeast (saccharomyces cerevisiae) set1 class and a class related to drosophila melanogaster ... | 2009 | 19855050 |
| development of inhibitors against trar quorum-sensing system in agrobacterium tumefaciens by molecular modeling of the ligand-receptor interaction. | the quorum sensing (qs) inhibitors that antagonize trar, a receptor protein for n-3-oxo-octanoyl-l-homoserine lactones (3-oxo-c8-hsl), a qs signal of agrobacterium tumefaciens were developed. the structural analogues of 3-oxo-c8-hsl were designed by in silico molecular modeling using sybyl packages, and synthesized by the solid phase organic synthesis (spos) method, where the carboxamide bond of 3-oxo-c8-hsl was replaced with a nicotinamide or a sulfonamide bond to make derivatives of n-nicotiny ... | 2009 | 19855933 |
| establishment of a system based on universal multiplex-pcr for screening genetically modified crops. | the rapid development of many genetically modified (gm) crops in the past two decades makes it necessary to introduce an alternative strategy for routine screening and identification. in this study, we established a universal multiplex pcr detection system which will effectively reduce the number of reactions needed for sample identification. the pcr targets of this system include the six most frequently used transgenic elements: cauliflower mosaic virus (camv) 35s promoter, agrobacterium tumefa ... | 2010 | 19855961 |
| the use of 35s and tnos expression elements in the measurement of genetically engineered plant materials. | an online survey was conducted by the international life sciences institute, food biotechnology committee, on the use of qualitative and quantitative polymerase chain reaction (pcr) assays for cauliflower mosaic virus 35s promoter and agrobacterium tumefaciens tnos dna sequence elements for the detection of genetically engineered (ge) crop plant material. forty-four testing laboratories around the world completed the survey. the results showed the widespread use of such methods, the multiplicity ... | 2010 | 19856176 |
| mutational analysis of the active site residues of a d: -psicose 3-epimerase from agrobacterium tumefaciens. | d-psicose 3-epimerase from agrobacterium tumefacience catalyzes the conversion of d: -fructose to d-psicose. according to mutational analysis, the ring at position 112, the negative charge at position 156, and the positive charge at position 215 were essential components for enzyme activity and for binding fructose and psicose. the surface contact area and distance to the bound substrate by molecular modeling suggest that the positive charge of arg215 was involved in stabilization of cis-endiol ... | 2010 | 19859667 |
| a study in entire chromosomes of violations of the intra-strand parity of complementary nucleotides (chargaff's second parity rule). | chargaff's rule of intra-strand parity (isp) between complementary mono/oligonucleotides in chromosomes is well established in the scientific literature. although a large numbers of papers have been published citing works and discussions on isp in the genomic era, scientists are yet to find all the factors responsible for such a universal phenomenon in the chromosomes. in the present work, we have tried to address the issue from a new perspective, which is a parallel feature to isp. the composit ... | 2009 | 19861381 |
| three cotton genes preferentially expressed in flower tissues encode actin-depolymerizing factors which are involved in f-actin dynamics in cells. | to investigate whether the high expression levels of actin-depolymerizing factor genes are related to pollen development, three ghadf genes (cdnas) were isolated and characterized in cotton. among them, ghadf6 and ghadf8 were preferentially expressed in petals, whereas ghadf7 displayed the highest level of expression in anthers, revealing its anther specificity. the ghadf7 transcripts in anthers reached its peak value at flowering, suggesting that its expression is developmentally-regulated in a ... | 2010 | 19861654 |
| an intracellular ph gradient in the anammox bacterium kuenenia stuttgartiensis as evaluated by 31p nmr. | the cytoplasm of anaerobic ammonium oxidizing (anammox) bacteria consists of three compartments separated by membranes. it has been suggested that a proton motive force may be generated over the membrane of the innermost compartment, the "anammoxosome". 31p nuclear magnetic resonance (nmr) spectroscopy was employed to investigate intracellular ph differences in the anammox bacterium kuenenia stuttgartiensis. with in vivo nmr, spectra were recorded of active, highly concentrated suspensions of k. ... | 2010 | 19862513 |
| the pseudomonas syringae type iii effector hopg1 targets mitochondria, alters plant development and suppresses plant innate immunity. | the bacterial plant pathogen pseudomonas syringae uses a type iii protein secretion system to inject type iii effectors into plant cells. primary targets of these effectors appear to be effector-triggered immunity (eti) and pathogen-associated molecular pattern (pamp)-triggered immunity (pti). the type iii effector hopg1 is a suppressor of eti that is broadly conserved in bacterial plant pathogens. here we show that hopg1 from p. syringae pv. tomato dc3000 also suppresses pti. interestingly, hop ... | 2010 | 19863557 |
| pyr/pyl/rcar family members are major in-vivo abi1 protein phosphatase 2c-interacting proteins in arabidopsis. | abscisic acid (aba) mediates resistance to abiotic stress and controls developmental processes in plants. the group-a pp2cs, of which abi1 is the prototypical member, are protein phosphatases that play critical roles as negative regulators very early in aba signal transduction. because redundancy is thought to limit the genetic dissection of early aba signalling, to identify redundant and early aba signalling proteins, we pursued a proteomics approach. we generated yfp-tagged abi1 arabidopsis ex ... | 2010 | 19874541 |
| transformation of the flax rust fungus, melampsora lini: selection via silencing of an avirulence gene. | rust fungi cause devastating diseases on many important food crops, with a damaging stem rust epidemic currently affecting wheat production in africa and the middle east. these parasitic fungi propagate exclusively on plants, precluding the use of many biotechnological tools available for other culturable fungi. in particular the lack of a stable transformation system has been an impediment to the genetic manipulation required for molecular analysis of rust pathogenicity. we have developed an ag ... | 2010 | 19874543 |
| agrobacterium-tumefaciens-mediated transformation of antifungal-lipopeptide-producing fungus coleophoma empetri f-11899. | the filamentous fungus coleophoma empetri f-11899 produces an echinocandin-like compound fr901379, the original source for micafungin which is prescribed to treat deep-seated mycoses. despite its industrial importance, no genetic information on c. empetri f-11899 is currently available. to characterize fr901379 biosynthetic genes by insertional mutagenesis and to improve the compound production genetically, agrobacterium tumefaciens-mediated transformation (atmt) was attempted to make genetic ma ... | 2009 | 19876630 |
| an inbred line of the diploid strawberry fragaria vesca f. semperflorens for genomic and molecular genetic studies in the rosaceae. | abstract: | 2009 | 19878589 |
| detection of quorum sensing signal molecules and mutation of luxs gene in vibrio ichthyoenteri. | some pathogenic species belonging to the vibrionaceae family have been shown to regulate virulence through a complicated network of quorum sensing systems. in this study, three kinds of n-acylhomoserine lactone (ahl) signal molecules were detected in vibrio ichthyoenteri da3, a pathogen of cultured turbot (scophthalmus maximus), with the agrobacterium tumefaciens reporter strain kyc55 (pjz372)(pjz384)(pjz410). da3 produced ahls during the entire growth phase, and the level of ahls increased, acc ... | 2010 | 19878720 |
| mechanisms and regulation of polar surface attachment in agrobacterium tumefaciens. | agrobacterium tumefaciens is a plant pathogen that transfers a segment of its own dna into host plants to cause crown gall disease. the infection process requires intimate contact between the infecting bacteria and the host tissue. a. tumefaciens attaches efficiently to plant tissues and to abiotic surfaces, and can establish complex biofilms at colonization sites. the dominant mode of attachment is via a single pole in contact with the surface. several different appendages, adhesins and adhesiv ... | 2009 | 19879182 |
| a zinc finger transcription factor art1 regulates multiple genes implicated in aluminum tolerance in rice. | aluminum (al) toxicity is the major limiting factor of crop production on acid soils, but some plant species have evolved ways of detoxifying al. here, we report a c2h2-type zinc finger transcription factor art1 (for al resistance transcription factor 1), which specifically regulates the expression of genes related to al tolerance in rice (oryza sativa). art1 is constitutively expressed in the root, and the expression level is not affected by al treatment. art1 is localized in the nucleus of all ... | 2009 | 19880795 |
| sfp-type 4'-phosphopantetheinyl transferase is indispensable for fungal pathogenicity. | in filamentous fungi, sfp-type 4'-phosphopantetheinyl transferases (pptases) activate enzymes involved in primary (alpha-aminoadipate reductase [aar]) and secondary (polyketide synthases and nonribosomal peptide synthetases) metabolism. we cloned the pptase gene ppt1 of the maize anthracnose fungus colletotrichum graminicola and generated pptase-deficient mutants (deltappt1). deltappt1 strains were auxotrophic for lys, unable to synthesize siderophores, hypersensitive to reactive oxygen species, ... | 2009 | 19880801 |
| nourseothricin acetyltransferase: a new dominant selectable marker for the dermatophyte trichophyton mentagrophytes. | dermatophytes are filamentous fungi that colonize the keratinized layer of human and animal skin. the availability of several selectable markers for dermatophyte gene manipulation would provide important tools to understand the genetic properties of this fungal group. in this study, we report the nourseothricin resistance gene nat1 that confers resistance to the aminoglycoside antibiotic nourseothricin as a dominant marker in trichophyton mentagrophytes. the nat cassette was introduced into t. m ... | 2010 | 19886766 |
| ectopic expression of ptarhe1, encoding a poplar ring-h2 protein with e3 ligase activity, alters plant development and induces defence-related responses. | ring (really interesting new gene)-h2 domain-containing proteins are widely represented in plants and play important roles in the regulation of many developmental processes as well as in plant-environment interactions. in the present report, experiments were performed to unravel the role of the poplar gene ptarhe1, coding for a ring-h2 protein. in vitro ubiquitination assays indicate a functional e3 ligase activity for ptarhe1 with the specific e2 ubiquitin-conjugating enzyme ubch5a. the overexp ... | 2010 | 19892745 |
| [agrobacterium tumefaciens mediated chitinase and beta-1,3-glucanase gene transformation for pinellia ternata]. | to obtain transgenic pinellia ternata plants resistant to fungus by transfer chitinase and beta-1,3-glucanase gene from trichoderma harzianum. | 2009 | 19894502 |
| a genomic island defines subspecies-specific virulence features of the host-adapted pathogen campylobacter fetus subsp. venerealis. | the pathogen campylobacter fetus comprises two subspecies, c. fetus subsp. fetus and c. fetus subsp. venerealis. although these taxa are highly related on the genome level, they are adapted to distinct hosts and tissues. c. fetus subsp. fetus infects a diversity of hosts, including humans, and colonizes the gastrointestinal tract. in contrast, c. fetus subsp. venerealis is largely restricted to the bovine genital tract, causing epidemic abortion in these animals. in light of their close genetic ... | 2010 | 19897645 |
| metabolic engineering of fungal strains for conversion of d-galacturonate to meso-galactarate. | d-galacturonic acid can be obtained by hydrolyzing pectin, which is an abundant and low value raw material. by means of metabolic engineering, we constructed fungal strains for the conversion of d-galacturonate to meso-galactarate (mucate). galactarate has applications in food, cosmetics, and pharmaceuticals and as a platform chemical. in fungi d-galacturonate is catabolized through a reductive pathway with a d-galacturonate reductase as the first enzyme. deleting the corresponding gene in the f ... | 2010 | 19897761 |
| functional analysis of an arabidopsis thaliana abiotic stress-inducible facilitated diffusion transporter for monosaccharides. | sugars play indispensable roles in biological reactions and are distributed into various tissues or organelles via transporters in plants. under abiotic stress conditions, plants accumulate sugars as a means to increase stress tolerance. here, we report an abiotic stress-inducible transporter for monosaccharides from arabidopsis thaliana that is termed esl1 (erd six-like 1). expression of esl1 was induced under drought and high salinity conditions and with exogenous application of abscisic acid. ... | 2010 | 19901034 |
| efficient operation of nad(p)h dehydrogenase requires supercomplex formation with photosystem i via minor lhci in arabidopsis. | in higher plants, the chloroplast nad(p)h dehydrogenase (ndh) complex mediates photosystem i (psi) cyclic and chlororespiratory electron transport. we reported previously that ndh interacts with the psi complex to form a supercomplex (ndh-psi). in this study, ndh18 and fkbp16-2 (fk506 binding protein 16-2), detected in the ndh-psi supercomplex by mass spectrometry, were shown to be ndh subunits by the analysis of their knockdown lines. on the basis of extensive mutant characterization, we propos ... | 2009 | 19903870 |
| studying the copy number of ribosomal protein l7/l12. | studying the copy number of ribosomal protein l7/l12 was performed using monoclonal antibody 3g9 to the linear epitope on the c-terminal domain of this protein from escherichia coli. immunohistochemical study showed that agrobacterium tumefaciens ribosomes include 6 copies of protein l7/l12. our results suggest that the copy number of this protein has an evolutionary role. | 2009 | 19907745 |
| novel insights about class 2 integrons from experimental and genomic epidemiology. | in order to contribute to the knowledge of the architecture and epidemiology of class 2 integrons, we performed a class 2 integron molecular survey in which we analyzed 726 isolates in two bacterial populations from environmental and nonepidemiologically related clinical samples, respectively, collected from 1982 to 2007. we recovered the inti2 gene from 130 of 726 isolates, most of which were clinical isolates, and only 1 (a psychrophilic pseudomonas sp.) was from a water sample. unlike the wid ... | 2010 | 19917745 |
| reverse genetics through random mutagenesis in histoplasma capsulatum. | the dimorphic fungal pathogen histoplasma capsulatum causes respiratory and systemic disease in humans and other mammals. progress in understanding the mechanisms underlying the biology and the pathogenesis of histoplasma has been hindered by a shortage of methodologies for mutating a gene of interest. | 2009 | 19919692 |
| identification in agrobacterium tumefaciens of the d-galacturonic acid dehydrogenase gene. | there are at least three different pathways for the catabolism of d-galacturonate in microorganisms. in the oxidative pathway, which was described in some prokaryotic species, d-galacturonate is first oxidised to meso-galactarate (mucate) by a nicotinamide adenine dinucleotide (nad)-dependent dehydrogenase (ec 1.1.1.203). in the following steps of the pathway mucate is converted to 2-keto-glutarate. the enzyme activities of this catabolic pathway have been described while the corresponding gene ... | 2010 | 19921179 |
| h135a controls the redox activity of the sco copper center. kinetic and spectroscopic studies of the his135ala variant of bacillus subtilis sco. | sco-like proteins contain copper bound by two cysteines and a histidine residue. although their function is still incompletely understood, there is a clear involvement with the assembly of cytochrome oxidases that contain the cu(a) center in subunit 2, possibly mediating the transfer of copper into the cu(a) binuclear site. we are investigating the reaction chemistry of bsco, the homologue from bacillus subtilis. our studies have revealed that bsco behaves more like a redox protein than a metall ... | 2009 | 19921776 |
| new and unexpected insights into the modulation of luxr-type quorum sensing by cyclic dipeptides. | quorum sensing (qs) is under the control of n-acylated l-homoserine lactones (ahls) and their cognate receptors (luxr-type proteins) in gram-negative bacteria and plays a major role in mediating host-bacteria interactions by these species. certain cyclic dipeptides (2,5-diketopiperazines, dkps) have been isolated from bacteria and reported to activate or inhibit luxr-type proteins in ahl biosensor strains, albeit at significantly higher concentrations than native lactones. these reports have pro ... | 2009 | 19928886 |
| high level protein expression in plants through the use of a novel autonomously replicating geminivirus shuttle vector. | we constructed a novel autonomously replicating gene expression shuttle vector, with the aim of developing a system for transiently expressing proteins at levels useful for commercial production of vaccines and other proteins in plants. the vector, pric, is based on the mild strain of the geminivirus bean yellow dwarf virus (beydv-m) and is replicationally released into plant cells from a recombinant agrobacterium tumefaciens ti plasmid. pric differs from most other geminivirus-based vectors in ... | 2010 | 19929900 |
| high-level hiv-1 nef transient expression in nicotiana benthamiana using the p19 gene silencing suppressor protein of artichoke mottled crinckle virus. | in recent years, different hiv antigens have been successfully expressed in plants by either stable transformation or transient expression systems. among hiv proteins, nef is considered a promising target for the formulation of a multi-component vaccine due to its implication in the first steps of viral infection. attempts to express nef as a single protein product (not fused to a stabilizing protein) in transgenic plants resulted in disappointingly low yields (about 0.5% of total soluble protei ... | 2009 | 19930574 |
| use of nfsb, encoding nitroreductase, as a reporter gene to determine the mutational spectrum of spontaneous mutations in neisseria gonorrhoeae. | organisms that are sensitive to nitrofurantoin express a nitroreductase. since bacterial resistance to this compound results primarily from mutations in the gene encoding nitroreductase, the resulting loss of function of nitroreductase results in a selectable phenotype; resistance to nitrofurantoin. we exploited this direct selection for mutation to study the frequency at which spontaneous mutations arise (transitions and transversions, insertions and deletions). | 2009 | 19930647 |
| [establishment of high efficiency genetic transformation system of maize mediated by agrobacterium tumefaciens]. | in order to establish high-frequency regeneration and high-efficiency genetic transformation system in maize, the significance of the 11 factors influencing maize embryonic callus induction and 9 factors affecting embryonic callus differentiation was researched by orthogonal experiment. the results showed that genotype had highly significant impact on induction of embryonic callus. the concentration of 6-ba, agno3, 2,4-d, aba, and medium are the significant factors. the multi-comparison showed t ... | 2009 | 19933098 |
| gnom-like1/ermo1 and sec24a/ermo2 are required for maintenance of endoplasmic reticulum morphology in arabidopsis thaliana. | the endoplasmic reticulum (er) is composed of tubules, sheets, and three-way junctions, resulting in a highly conserved polygonal network in all eukaryotes. the molecular mechanisms responsible for the organization of these structures are obscure. to identify novel factors responsible for er morphology, we employed a forward genetic approach using a transgenic arabidopsis thaliana plant (gfp-h) with fluorescently labeled er. we isolated two mutants with defects in er morphology and designated th ... | 2009 | 19933201 |
| developing a systems biology approach to study disease progression caused by heterodera glycines in glycine max. | | 2007 | 19936075 |
| [influence of pseudomonas aureofaciens exopolysaccharides on tumour formation caused by agrobacterium tumefaciens]. | the ability of exopolysaccharides of pseudomonas aureofaciens strains ukm b-111 and ukm b-306, components of insectofungicidal preparation gaupsin, to influence the process of tumour formation caused by agrobacterium tumefaciens. bacterial polysaccharides, obtained on kozer medium with glucose (possible alginates) blocked agrobacterium cell adhesion by 29-49%. those obtained on the medium with sucrose polysaccharides (possible levans) by 30-75% inhibit later stages of tumour formation. the paper ... | 2009 | 19938600 |
| [antitumor activity of some complex preparations in the culture of potato cells transformed by agrobacterium tumefaciens]. | antitumor and antibacterial activity of complex preparations consisting of yeast mannan, diacetile-2,4-dioxohexahidro-1,3,5-triasine, cianohyanidine, alcansulfonic acids (emulsifier e-30), and microbial metabolites was studied. the investigation was carrying out on explants of tuber potato parenchyma infected by agrobacterium tumefaciens. we found that preparations have the antitumor activity. the most activity was exhibited by addition of preparations to the cultural medium and treatment of exp ... | 2009 | 19938633 |
| gene disruption and characterization of a class v chitin synthase in botrytis cinerea. | cell-wall chitin biosynthesis in the phytopathogenic fungus botrytis cinerea involves 7 classes of chitin synthases. in this study, we disrupted a gene encoding a chitin synthase with a myosin-like motor domain (bcchsv) through agrobacterium tumefaciens mediated transformation. the resulting mutant was not significantly affected in either growth characteristics or pathogenicity on tomato leaves. surprisingly, the bcchsv mutant exhibited a 31% (m/m) increase in its chitin content compared with th ... | 2009 | 19940935 |
| disruption of the chitin synthase gene chs1 from fusarium asiaticum results in an altered structure of cell walls and reduced virulence. | natural resistance of wheat against fusarium head blight (fhb) is inadequate and new strategies for controlling the disease are required. chitin synthases that catalyze chitin biosynthesis would be an ideal target for antifungal agents. in this study, a class i chitin synthase gene (chs1) from fusarium asiaticum, the predominant species of fhb pathogens on wheat in china, was functionally disrupted via agrobacterium tumefaciens-mediated transformation. specific disruption of the chs1 gene result ... | 2010 | 19941967 |
| pseudomonas aeruginosa ospr is an oxidative stress sensing regulator that affects pigment production, antibiotic resistance and dissemination during infection. | oxidative stress is one of the main challenges bacteria must cope with during infection. here, we identify a new oxidative stress sensing and response ospr (oxidative stress response and pigment production regulator) gene in pseudomonas aeruginosa. deletion of ospr leads to a significant induction in h(2)o(2) resistance. this effect is mediated by de-repression of pa2826, which lies immediately upstream of ospr and encodes a glutathione peroxidase. constitutive expression of ospr alters pigment ... | 2010 | 19943895 |
| going green in cryptococcus neoformans: the recycling of a selectable drug marker. | cryptococcus neoformans is an opportunistic fungal pathogen that primarily affects immunocompromised individuals. reverse genetics is commonly used to identify and characterize genes involved in a variety of cellular processes. in c. neoformans there is a limited set of positive selectable markers available to make gene deletions or other genetic manipulations. this has hampered the application of reverse genetics in this organism. we have adapted the bacteriophage p1 cre-loxp system for use in ... | 2010 | 19944774 |
| theoretical and structural analysis of the active site of the transcriptional regulators lasr and trar, using molecular docking methodology for identifying potential analogues of acyl homoserine lactones (ahls) with anti-quorum sensing activity. | in the present study the homology of transcriptional receptors luxr type were evaluated using as point of reference the receptors trar and lasr of the bacterial types agrobacterium tumefaciens and pseudomonas aureginosa respectively. a series of alignments were performed in order to demonstrate that the active site of the protein is conserved in wide range of gram negative bacteria. moreover, some docking calculations were carried out for analogs of the acyl homoserin lactones (ahls) and regulat ... | 2010 | 19945196 |
| biological diversity of prokaryotic type iv secretion systems. | type iv secretion systems (t4ss) translocate dna and protein substrates across prokaryotic cell envelopes generally by a mechanism requiring direct contact with a target cell. three types of t4ss have been described: (i) conjugation systems, operationally defined as machines that translocate dna substrates intercellularly by a contact-dependent process; (ii) effector translocator systems, functioning to deliver proteins or other macromolecules to eukaryotic target cells; and (iii) dna release/up ... | 2009 | 19946141 |
| [agrobacterium-mediated transformation of flax with a mutant tubulin gene responsible for resistance to dinitroaniline herbicides]. | agrobacterium tumefaciens was used to transform fiber flax with the pbituba8 plasmid carrying the mutant alpha-tubulin gene imparting resistance to dinitroaniline herbicides and the nptii selective marker gene imparting resistance to canamycin. the transformants were selected in parallel on media containing canamycin and trifluralin (a dinitroaniline herbicide). the transgenic nature of the resultant regenerants resistant to dinitroaniline herbicides was confirmed by means of southern blotting a ... | 2009 | 19947549 |
| control of cell proliferation, organ growth, and dna damage response operate independently of dephosphorylation of the arabidopsis cdk1 homolog cdka;1. | entry into mitosis is universally controlled by cyclin-dependent kinases (cdks). a key regulatory event in metazoans and fission yeast is cdk activation by the removal of inhibitory phosphate groups in the atp binding pocket catalyzed by cdc25 phosphatases. in contrast with other multicellular organisms, we show here that in the flowering plant arabidopsis thaliana, cell cycle control does not depend on sudden changes in the phosphorylation pattern of the pstaire-containing cdk1 homolog cdka;1. ... | 2009 | 19948791 |
| red light activates the sigmab-mediated general stress response of bacillus subtilis via the energy branch of the upstream signaling cascade. | the sigma(b)-dependent general stress response in the common soil bacterium bacillus subtilis can be elicited by a range of stress factors, such as starvation or an ethanol, salt, or heat shock, via a complex upstream signaling cascade. additionally, sigma(b) can be activated by blue light via the phototropin homologue ytva, a component of the environmental branch of the signaling cascade. here we use a reporter-gene fusion to show that sigma(b) can also be activated by red light via the energy ... | 2010 | 19948797 |
| distribution of cepacian biosynthesis genes among environmental and clinical burkholderia strains and role of cepacian exopolysaccharide in resistance to stress conditions. | the genus burkholderia includes strains pathogenic to animals and plants, bioremediators, or plant growth promoters. genome sequence analyses of representative burkholderia cepacia complex (bcc) and non-bcc strains for the presence of the bce-i gene cluster, directing the biosynthesis of the exopolysaccharide (eps) cepacian, further extended this previously described cluster by another 9 genes. the genes in the bce-ii cluster were named bcem to bceu and encode products putatively involved in nuc ... | 2010 | 19948863 |
| rapid identification of bacteria in positive blood culture broths by matrix-assisted laser desorption ionization-time of flight mass spectrometry. | matrix-assisted laser desorption ionization-time of flight (maldi-tof) mass spectrometry is a rapid, accurate method for identifying bacteria and fungi recovered on agar culture media. we report herein a method for the direct identification of bacteria in positive blood culture broths by maldi-tof mass spectrometry. a total of 212 positive cultures were examined, representing 32 genera and 60 species or groups. the identification of bacterial isolates by maldi-tof mass spectrometry was compared ... | 2010 | 19955282 |
| pre- and post-agroinfection strategies for efficient leaf disk transformation and regeneration of transgenic strawberry plants. | following previously described agrobacterium tumefaciens-mediated transformation procedures for fragaria x ananassa duch. 'chandler', we undertook several experiments to establish the importance of some parameters affecting transformation. the most important factor that increased the percent recovery of transformants was the introduction of a pre-selection phase, in-between co-cultivation and selection, in which leaf disks were cultured on pre-selection regeneration medium containing validamycin ... | 2010 | 19956955 |
| identification, functional studies, and genomic comparisons of new members of the nnrr regulon in rhodobacter sphaeroides. | analysis of the rhodobacter sphaeroides 2.4.3 genome revealed four previously unidentified sequences similar to the binding site of the transcriptional regulator nnrr. expression studies demonstrated that three of these sequences are within the promoters of genes, designated paz, noref, and cdga, in the nnrr regulon, while the status of the fourth sequence, within the tat operon promoter, remains uncertain. nnrv, under control of a previously identified nnrr site, was also identified. paz encode ... | 2010 | 19966004 |
| expression of a synthesized gene encoding cationic peptide cecropin b in transgenic tomato plants protects against bacterial diseases. | the cationic lytic peptide cecropin b (cb), isolated from the giant silk moth (hyalophora cecropia), has been shown to effectively eliminate gram-negative and some gram-positive bacteria. in this study, the effects of chemically synthesized cb on plant pathogens were investigated. the s(50)s (the peptide concentrations causing 50% survival of a pathogenic bacterium) of cb against two major pathogens of the tomato, ralstonia solanacearum and xanthomonas campestris pv. vesicatoria, were 529.6 micr ... | 2010 | 19966019 |
| a root-expressed magnesium transporter of the mrs2/mgt gene family in arabidopsis thaliana allows for growth in low-mg2+ environments. | the mrs2/mgt gene family in arabidopsis thaliana belongs to the superfamily of cora-mrs2-alr-type membrane proteins. proteins of this type are characterized by a gmn tripeptide motif (gly-met-asn) at the end of the first of two c-terminal transmembrane domains and have been characterized as magnesium transporters. using the recently established mag-fura-2 system allowing direct measurement of mg(2+) uptake into mitochondria of saccharomyces cerevisiae, we find that all members of the arabidopsis ... | 2009 | 19966073 |
| expression of human cytomegalovirus pp150 gene in transgenic vicia faba l. and immunogenicity of pp150 protein in mice. | the pp150 gene of human cytomegalovirus (hcmv) was transferred into vicia faba plants by agrobacterium tumefaciens-mediated transformation. three of five hygromycin resistant v. faba plants were identified as positive by pcr and dot-blot hybridization. the elisa results indicated that pp150 protein from three plants of transformed v. faba leaves and seeds made up 0.005-0.015% of the total soluble protein. the results of detection by immunoblot and inhibition of immunofluorescent assay (ifa) show ... | 2010 | 19969470 |
| arabidopsis thaliana polyol/monosaccharide transporters 1 and 2: fructose and xylitol/h+ symporters in pollen and young xylem cells. | the genome of arabidopsis thaliana contains six genes, atpmt1 to atpmt6 (arabidopsis thaliana polyol/monosaccharide transporter 1-6), which form a distinct subfamily within the large family of more than 50 monosaccharide transporter-like (mst-like) genes. so far, only atpmt5 [formerly named atplt5 (at3g18830)] has been characterized and was shown to be a plasma membrane-localized h(+)-symporter with broad substrate specificity. the characterization of atpmt1 (at2g16120) and atpmt2 (at2g16130), t ... | 2010 | 19969532 |
| agrobacterium tumefaciens-mediated transformation of guignardia citricarpa. | guignardia citricarpa, the causal agent of citrus black spot, was successfully transformed via agrobacterium tumefaciens with cassettes for gfp and bar expression. transformation is essential to understand the role of genes during interaction between plants and its pathogens. using a binary plasmid vector based in the ppzp201bk, both germinated conidia and physically fragmented hyphae of g. citricarpa were transformed. eight independent transformants of g. citricarpa resistant to ammonium glifos ... | 2010 | 19995579 |
| early transcriptomic events in microdissected arabidopsis nematode-induced giant cells. | root-knot nematodes differentiate highly specialized feeding cells in roots (giant cells, gcs), through poorly characterized mechanisms that include extensive transcriptional changes. while global transcriptome analyses have used galls, which are complex root structures that include gcs and surrounding tissues, no global gene expression changes specific to gcs have been described. we report on the differential transcriptome of gcs versus root vascular cells, induced in arabidopsis by meloidogyne ... | 2010 | 20003167 |
| ubiquitination of tombusvirus p33 replication protein plays a role in virus replication and binding to the host vps23p escrt protein. | post-translational modifications of viral replication proteins could be widespread phenomena during the replication of plus-stranded rna viruses. in this article, we identify two lysines in the tombusvirus p33 replication co-factor involved in ubiquitination and show that the same lysines are also important for the p33 to interact with the host vps23p escrt-i factor. we find that the interaction of p33 with vps23p is also affected by a "late-domain"-like sequence in p33. the combined mutations o ... | 2010 | 20004458 |
| crystal structure and substrate specificity of plant adenylate isopentenyltransferase from humulus lupulus: distinctive binding affinity for purine and pyrimidine nucleotides. | cytokinins are important plant hormones, and their biosynthesis most begins with the transfer of isopentenyl group from dimethylallyl diphosphate (dmapp) to the n6-amino group of adenine by either adenylate isopentenyltransferase (aipt) or trna-ipt. plant aipts use atp/adp as an isopentenyl acceptor and bacterial aipts prefer amp, whereas trna-ipts act on specific sites of trna. here, we present the crystal structure of an aipt-atp complex from humulus lupulus (hlaipt), which is similar to the p ... | 2010 | 20007608 |
| virulence factors encoded by legionella longbeachae identified on the basis of the genome sequence analysis of clinical isolate d-4968. | legionella longbeachae causes most cases of legionellosis in australia and may be underreported worldwide due to the lack of l. longbeachae-specific diagnostic tests. l. longbeachae displays distinctive differences in intracellular trafficking, caspase 1 activation, and infection in mouse models compared to legionella pneumophila, yet these two species have indistinguishable clinical presentations in humans. unlike other legionellae, which inhabit freshwater systems, l. longbeachae is found pred ... | 2010 | 20008069 |
| comparative genomics and transduction potential of enterococcus faecalis temperate bacteriophages. | to determine the relative importance of temperate bacteriophage in the horizontal gene transfer of fitness and virulence determinants of enterococcus faecalis, a panel of 47 bacteremia isolates were treated with the inducing agents mitomycin c, norfloxacin, and uv radiation. thirty-four phages were purified from culture supernatants and discriminated using pulsed-field gel electrophoresis (pfge) and restriction mapping. from these analyses the genomes of eight representative phages were pyrosequ ... | 2010 | 20008075 |
| antagonistic hlh/bhlh transcription factors mediate brassinosteroid regulation of cell elongation and plant development in rice and arabidopsis. | in rice (oryza sativa), brassinosteroids (brs) induce cell elongation at the adaxial side of the lamina joint to promote leaf bending. we identified a rice mutant (ili1-d) showing an increased lamina inclination phenotype similar to that caused by br treatment. the ili1-d mutant overexpresses an hlh protein homologous to arabidopsis thaliana paclobutrazol resistance1 (pre1) and the human inhibitor of dna binding proteins. overexpression and rna interference suppression of ili1 increase and reduc ... | 2009 | 20009022 |
| current state of coenzyme q(10) production and its applications. | coenzyme q(10) (coq(10)), an obligatory cofactor in the aerobic respiratory electron transfer for energy generation, is formed from the conjugation of a benzoquinone ring with a hydrophobic isoprenoid chain. coq(10) is now used as a nutritional supplement because of its antioxidant properties and is beneficial in the treatment of several human diseases when administered orally. bioprocesses have been developed for the commercial production of coq(10) because of its increased demand, and these bi ... | 2010 | 20012276 |
| agrobacterium tumefaciens-mediated transformation of withania somnifera (l.) dunal: an important medicinal plant. | this report describes agrobacterium tumefaciens-mediated transformation of withania somnifera--an important indian medicinal plant. a. tumefaciens strain lba4404, containing the binary vector pig121hm was used for transformation, along with the gusa reporter gene with intron under the transcriptional control of the cauliflower mosaic virus (camv) 35s promoter. the leaf segments from two-and-a-half-month-old green house-grown seedlings were more efficient in transformation, as compared to those f ... | 2010 | 20012541 |
| hydrophobin fusions for high-level transient protein expression and purification in nicotiana benthamiana. | insufficient accumulation levels of recombinant proteins in plants and the lack of efficient purification methods for recovering these valuable proteins have hindered the development of plant biotechnology applications. hydrophobins are small and surface-active proteins derived from filamentous fungi that can be easily purified by a surfactant-based aqueous two-phase system. in this study, the hydrophobin hfbi sequence from trichoderma reesei was fused to green fluorescent protein (gfp) and tran ... | 2010 | 20018596 |
| sinorhizobium meliloti phospholipase c required for lipid remodeling during phosphorus limitation. | rhizobia are gram-negative soil bacteria able to establish nitrogen-fixing root nodules with their respective legume host plants. besides phosphatidylglycerol, cardiolipin, and phosphatidylethanolamine, rhizobial membranes contain phosphatidylcholine (pc) as a major membrane lipid. under phosphate-limiting conditions of growth, some bacteria replace their membrane phospholipids with lipids lacking phosphorus. in sinorhizobium meliloti, these phosphorus-free lipids are sulfoquinovosyl diacylglyce ... | 2010 | 20018679 |
| modal codon usage: assessing the typical codon usage of a genome. | most genomes are heterogeneous in codon usage, so a codon usage study should start by defining the codon usage that is typical to the genome. although this is commonly taken to be the genomewide average, we propose that the mode-the codon usage that matches the most genes-provides a more useful approximation of the typical codon usage of a genome. we provide a method for estimating the modal codon usage, which utilizes a continuous approximation to the number of matching genes and a simplex opti ... | 2010 | 20018979 |
| nmr assignments of the dna binding domain of ml4 protein from mesorhizobium loti. | ml4 protein from mesorhizobium loti has a 58% sequence identity with the ros protein from agrobacterium tumefaciens that contains a prokaryotic cys(2)his(2) zinc finger domain. interestingly, ml4 is a zinc-lacking protein that does not contain the cys(2)his(2) motif and is able to bind the ros dna target sequence with high affinity. here we report the (1)h, (15)n and (13)c nmr assignments of the ml4 protein dna binding domain (residue 52-151), as an important step toward elucidating at a molecul ... | 2010 | 20020226 |
| multilocus sequence typing supports the hypothesis that ochrobactrum anthropi displays a human-associated subpopulation. | ochrobactrum anthropi is a versatile bacterial species with strains living in very diverse habitats. it is increasingly recognized as opportunistic pathogen in hospitalized patients. the population biology of the species particularly with regard to the characteristics of the human isolates is being investigated. to address this issue, we proposed a polyphasic approach consisting in multi-locus sequence typing (mlst), multi-locus phylogeny, genomic-based fingerprinting by pulsed-field gel electro ... | 2009 | 20021660 |
| the tobacco map215/dis1-family protein tmbp200 is required for the functional organization of microtubule arrays during male germline establishment. | the haploid microspore division during pollen development in flowering plants is an intrinsically asymmetric division which establishes the male germline for sexual reproduction. arabidopsis gem1 mutants lack the male germline as a result of disturbed microspore polarity, division asymmetry, and cytokinesis and represent loss-of-function mutants in mor1/gem1, a plant orthologue of the conserved map215/dis1 microtubule associated protein (map) family. this provides genetic evidence for the role o ... | 2010 | 20022922 |
| characterization of a gene family of outer membrane proteins (ropb) in rhizobium leguminosarum bv. viciae vf39sm and the role of the sensor kinase chvg in their regulation. | the outer membrane of gram-negative bacteria represents the interface between the bacterium and its external environment. it has a critical role as a protective barrier against harmful substances and is also important in host-bacteria interactions representing the initial physical point of contact between the host cell and bacterial cell. ropb is a previously identified outer membrane protein from rhizobium leguminosarum bv. viciae that is present in free-living cells but absent in bacteroids (h ... | 2010 | 20023026 |
| mreb drives de novo rod morphogenesis in caulobacter crescentus via remodeling of the cell wall. | mreb, the bacterial actin-like cytoskeleton, is required for the rod morphology of many bacterial species. disruption of mreb function results in loss of rod morphology and cell rounding. here, we show that the widely used mreb inhibitor a22 causes mreb-independent growth inhibition that varies with the drug concentration, culture medium conditions, and bacterial species tested. mp265, an a22 structural analog, is less toxic than a22 for growth yet equally efficient for disrupting the mreb cytos ... | 2010 | 20023035 |
| rhizobium leguminosarum hupe encodes a nickel transporter required for hydrogenase activity. | synthesis of the hydrogen uptake (hup) system in rhizobium leguminosarum bv. viciae requires the function of an 18-gene cluster (hupslcdefghijk-hypabfcdex). among them, the hupe gene encodes a protein showing six transmembrane domains for which a potential role as a nickel permease has been proposed. in this paper, we further characterize the nickel transport capacity of hupe and that of the translated product of hupe2, a hydrogenase-unlinked gene identified in the r. leguminosarum genome. hupe2 ... | 2010 | 20023036 |
| generation of backbone-free, low transgene copy plants by launching t-dna from the agrobacterium chromosome. | in both applied and basic research, agrobacterium-mediated transformation is commonly used to introduce genes into plants. we investigated the effect of three agrobacterium tumefaciens strains and five transferred (t)-dna origins of replication on transformation frequency, transgene copy number, and the frequency of integration of non-t-dna portions of the t-dna-containing vector (backbone) into the genome of arabidopsis (arabidopsis thaliana) and maize (zea mays). launching t-dna from the pica ... | 2010 | 20023148 |
| mutations of an alpha1,6 mannosyltransferase inhibit endoplasmic reticulum-associated degradation of defective brassinosteroid receptors in arabidopsis. | asn-linked glycans, or the glycan code, carry crucial information for protein folding, transport, sorting, and degradation. the biochemical pathway for generating such a code is highly conserved in eukaryotic organisms and consists of ordered assembly of a lipid-linked tetradeccasaccharide. most of our current knowledge on glycan biosynthesis was obtained from studies of yeast asparagine-linked glycosylation (alg) mutants. by contrast, little is known about biosynthesis and biological functions ... | 2009 | 20023196 |
| arabidopsis formin3 directs the formation of actin cables and polarized growth in pollen tubes. | cytoplasmic actin cables are the most prominent actin structures in plant cells, but the molecular mechanism underlying their formation is unknown. the function of these actin cables, which are proposed to modulate cytoplasmic streaming and intracellular movement of many organelles in plants, has not been studied by genetic means. here, we show that arabidopsis thaliana formin3 (afh3) is an actin nucleation factor responsible for the formation of longitudinal actin cables in pollen tubes. the ar ... | 2009 | 20023198 |
| high-throughput transient transformation of arabidopsis roots enables systematic colocalization analysis of gfp-tagged proteins. | determination of the subcellular localization of an unknown protein is a major step towards the elucidation of its function. lately, the expression of proteins fused to fluorescent markers has been very popular and many approaches have been proposed to express these proteins. stable transformation using agrobacterium tumefaciens generates stable lines for downstream experiments, but is time-consuming. if only colocalization is required, transient techniques save time and effort. several methods ... | 2010 | 20023426 |
| cloning and molecular analysis of hlbzip1 and hlbzip2 transcription factors putatively involved in the regulation of the lupulin metabolome in hop (humulus lupulus l.). | hop (humulus lupulus l.), the essential source of beer flavor is of interest from a medicinal perspective in view of its high content in health-beneficial terpenophenolics including prenylflavonoids. the dissection of biosynthetic pathway(s) of these compounds in lupulin glands, as well as its regulation by transcription factors (tfs), is important for efficient biotechnological manipulation of the hop metabolome. tfs of the bzip class were preselected from the hop transcriptome using a cdna-afl ... | 2010 | 20028133 |
| the small subunit of snapdragon geranyl diphosphate synthase modifies the chain length specificity of tobacco geranylgeranyl diphosphate synthase in planta. | geranyl diphosphate (gpp), the precursor of many monoterpene end products, is synthesized in plastids by a condensation of dimethylallyl diphosphate and isopentenyl diphosphate (ipp) in a reaction catalyzed by homodimeric or heterodimeric gpp synthase (gpps). in the heterodimeric enzymes, a noncatalytic small subunit (gpps.ssu) determines the product specificity of the catalytic large subunit, which may be either an active geranylgeranyl diphosphate synthase (ggpps) or an inactive ggpps-like pro ... | 2009 | 20028839 |
| identification of a novel abc transporter required for desiccation tolerance, and biofilm formation in rhizobium leguminosarum bv. viciae 3841. | rhizobium leguminosarum is a soil bacterium with the ability to form nitrogen-fixing nodules on the roots of leguminous plants. soil-dwelling, free-living r. leguminosarum often encounters desiccation stress, which impacts its survival within the soil. the mechanisms by which soil bacteria resist the effects of desiccation stress have been described. however, the role of the cell envelope in the desiccation tolerance mechanisms of rhizobia is relatively uncharacterized. using a transposon mutage ... | 2010 | 20030718 |
| structural biology: translocation chamber's secrets. | | 2009 | 20033031 |
| the mads-domain protein mpf1 of physalis floridana controls plant architecture, seed development and flowering time. | floral and vegetative development of plants is dependent on the combinatorial action of mads-domain transcription factors. members of the stmads11 subclade, such as mpf1 of physalis, are abundantly expressed in leaves as well as in floral organs, but their function is not yet clear. our studies with transgenic arabidopsis that over-express mpf1 suggest that mpf1 interacts with soc1 to determine flowering time. however, mpf1 rnai-mediated knockdown physalis plants revealed a complex phenotype wit ... | 2010 | 20033229 |
| a novel mannose-based selection system for plant transformation using celery mannose-6-phosphate reductase gene. | to investigate its potential application as a selectable marker for plant transformation, the mannitol producing, celery mannose-6-phosphate reductase gene (m6pr) was transformed into arabidopsis and tobacco using agrobacterium tumefaciens-mediated transformation. mannose-tolerance assays in transgenic materials revealed that the m6pr can act as a selectable marker gene in either a positive or a negative selection mode depending on the plant species. for mannose sensitive species, such as arabid ... | 2010 | 20033814 |
| multidrug efflux pump mdtbc of escherichia coli is active only as a b2c heterotrimer. | rnd (resistance-nodulation-division) family transporters in gram-negative bacteria frequently pump out a wide range of inhibitors and often contribute to multidrug resistance to antibiotics and biocides. an archetypal rnd pump of escherichia coli, acrb, is known to exist as a homotrimer, and this construction is essential for drug pumping through the functionally rotating mechanism. mdtbc, however, appears different because two pump genes coexist within a single operon, and genetic deletion data ... | 2010 | 20038594 |
| dgat1 and pdat1 acyltransferases have overlapping functions in arabidopsis triacylglycerol biosynthesis and are essential for normal pollen and seed development. | triacylglycerol (tag) biosynthesis is a principal metabolic pathway in most organisms, and tag is the major form of carbon storage in many plant seeds. acyl-coa:diacylglycerol acyltransferase 1 (dgat1) is the only acyltransferase enzyme that has been confirmed to contribute to tag biosynthesis in arabidopsis thaliana seeds. however, dgat1 null mutants display only a 20 to 40% decrease in seed oil content. to determine whether other enzymes contribute to tag synthesis, candidate genes were expres ... | 2009 | 20040537 |
| development of an agrobacterium-mediated transformation protocol for the tree-legume leucaena leucocephala using immature zygotic embryos. | the tree-legume leucaena leucocephala (leucaena) is used as a perennial fodder because of its fast-growing foliage, which is high in protein content. the use of leucaena as a fodder is however restricted due to the presence of the toxin mimosine. improvements in the nutritional contents as well as other agronomic traits of leucaena can be accomplished through genetic transformation. the objective of this research was to develop a transformation protocol for leucaena using phosphinothricin resist ... | 2009 | 20041041 |
| selection system and co-cultivation medium are important determinants of agrobacterium-mediated transformation of sugarcane. | a reproducible method for transformation of sugarcane using various strains of agrobacterium tumefaciens (a. tumefaciens) (agl0, agl1, eha105 and lba4404) has been developed. the selection system and co-cultivation medium were the most important factors determining the success of transformation and transgenic plant regeneration. plant regeneration at a frequency of 0.8-4.8% occurred only when callus was transformed with a. tumefaciens carrying a newly constructed superbinary plasmid containing n ... | 2010 | 20041254 |
| virus infection elevates transcriptional activity of mir164a promoter in plants. | micro rnas (mirs) constitute a large group of endogenous small rnas that have crucial roles in many important plant functions. virus infection and transgenic expression of viral proteins alter accumulation and activity of mirs and so far, most of the published evidence involves post-transcriptional regulations. | 2009 | 20042107 |
| production of compact plants by overexpression of atshi in the ornamental kalanchoë. | growth retardation is an important breeding aim and an essential part of horticultural plant production. here, the potential of transferring the arabidopsis short internode (shi) mutant phenotype was explored by expressing the atshi gene in the popular ornamental plant kalanchoë. a 35s-atshi construct was produced and transferred into eight genetically different cultivars of kalanchoë by agrobacterium tumefaciens. the resulting transgenic plants showed dwarfing phenotypes like reduced plant heig ... | 2010 | 20051037 |
| expression, purification, crystallization and preliminary x-ray analysis of maleylacetate reductase from burkholderia sp. strain sj98. | maleylacetate reductase (ec 1.3.1.32) is an important enzyme that is involved in the degradation pathway of aromatic compounds and catalyzes the reduction of maleylacetate to 3-oxoadipate. the gene pnpd encoding maleylacetate reductase in burkholderia sp. strain sj98 was cloned, expressed in escherichia coli and purified by affinity chromatography. the enzyme was crystallized in both native and semet-derivative forms by the sitting-drop vapour-diffusion method using peg 3350 as a precipitant at ... | 2009 | 20054138 |
| purification, crystallization and preliminary x-ray diffraction analysis of cif, a virulence factor secreted by pseudomonas aeruginosa. | the opportunistic pathogen pseudomonas aeruginosa secretes a protein that triggers the accelerated degradation of the cystic fibrosis transmembrane conductance regulator (cftr) in airway epithelial cells. this protein, which is known as the cftr inhibitory factor (cif), acts as a virulence factor and may facilitate airway colonization by p. aeruginosa. based on sequence similarity cif appears to be an epoxide hydrolase (eh), but it lacks several of the conserved features found in the active site ... | 2010 | 20057063 |
| catheter associated bloodstream infection caused by r. radiobacter. | rhizobium radiobacter is a gram negative bacillus that is infrequently recognized in clinical specimens but is emerging as an opportunistic human pathogen. infections due to rhizobium radiobacter are strongly related to the presence of foreign plastic material and effective treatment often requires removal of the device. we report a case of r. radiobacter bloodstream infection associated with a central venous catheter which was easily controlled by antimicrobial treatment and did not require rem ... | 2010 | 20061769 |
| a simplified and efficient method for transformation and gene tagging of ustilago maydis using frozen cells. | ustilago maydis is an important model fungal organism for diverse studies. little improvement has been made in the method for its transformation since the peg-mediated transfection of spheroplasts that was reported more than 20years ago. we have constructed binary t-dna vectors carrying hygromycin and nourseothricin resistance gene cassettes and have developed a highly efficient method for transformation of this fungus based on agrobacterium tumefaciens-mediated transformation (atmt). through a ... | 2010 | 20079868 |
| composite system mediates two-step dna uptake into helicobacter pylori. | the gram-negative gastric pathogen helicobacter pylori depends on natural transformation for genomic plasticity, which leads to host adaptation and spread of resistances. here, we show that h. pylori takes up covalently labeled fluorescent dna preferentially at the cell poles and that uptake is dependent on the type iv secretion system comb. by titration of external ph and detection of accessibility of the fluorophor by protons, we localized imported fluorescent dna in the periplasm. single mole ... | 2010 | 20080542 |
| the quorum-quenching n-acyl homoserine lactone acylase pvdq is an ntn-hydrolase with an unusual substrate-binding pocket. | in many gram-negative pathogens, their virulent behavior is regulated by quorum sensing, in which diffusible signals such as n-acyl homoserine lactones (ahls) act as chemical messaging compounds. enzymatic degradation of these diffusible signals by, e.g., lactonases or amidohydrolases abolishes ahl regulated virulence, a process known as quorum quenching. here we report the first crystal structure of an ahl amidohydrolase, the ahl acylase pvdq from pseudomonas aeruginosa. pvdq has a typical alph ... | 2010 | 20080736 |
| expanding small-molecule functional metagenomics through parallel screening of broad-host-range cosmid environmental dna libraries in diverse proteobacteria. | the small-molecule biosynthetic diversity encoded within the genomes of uncultured bacteria is an attractive target for the discovery of natural products using functional metagenomics. phenotypes commonly associated with the production of small molecules, such as antibiosis, altered pigmentation, or altered colony morphology, are easily identified from screens of arrayed metagenomic library clones. however, functional metagenomic screening methods are limited by their intrinsic dependence on a h ... | 2010 | 20081001 |
| the receiver domain of hybrid histidine kinase vira: an enhancing factor for vir gene expression in agrobacterium tumefaciens. | the plant pathogen agrobacterium tumefaciens expresses virulence (vir) genes in response to chemical signals found at the site of a plant wound. vira, a hybrid histidine kinase, and its cognate response regulator, virg, regulate vir gene expression. the receiver domain at the carboxyl end of vira has been described as an inhibitory element because its removal increased vir gene expression relative to that of full-length vira. however, experiments that characterized the receiver region as an inhi ... | 2010 | 20081031 |
| a candidate gene osapc6 of anaphase-promoting complex of rice identified through t-dna insertion. | a dwarf mutant (oryza sativa anaphase-promoting complex 6 (osapc6)) of rice cultivar basmati 370 with 50% reduced plant height as compared to the wild type was isolated by agrobacterium tumefaciens-mediated transformation using hm(r) ds cassette. this mutant was found to be insensitive to exogenous gibberellic acid (ga(3)) application. homozygous mutant plants showed incomplete penetrance and variable expressivity for plant height and pleiotropic effects including gibberellic acid insensitivity, ... | 2010 | 20091079 |
| inhibitors of the pseudomonas aeruginosa quorum-sensing regulator, qscr. | qscr is a quorum-sensing (qs) signal receptor that controls expression of virulence genes in the prevalent opportunistic pathogen, pseudomonas aeruginosa. unlike the previously reported luxr-type qs receptor proteins, that is, lasr and trar, qscr can be obtained as an apo-protein that can reversibly form an active complex in vitro with its cognate signal molecule, 3-oxododecanoyl-homoserine lactone (3oc12-hsl), and subsequently bind to target promoter dna sequences. to search for potential qs in ... | 2010 | 20091741 |