Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| expression of hiv-1 antigens in plants as potential subunit vaccines. | human immunodeficiency virus type 1 (hiv-1) has infected more than 40 million people worldwide, mainly in sub-saharan africa. the high prevalence of hiv-1 subtype c in southern africa necessitates the development of cheap, effective vaccines. one means of production is the use of plants, for which a number of different techniques have been successfully developed. hiv-1 pr55gag is a promising hiv-1 vaccine candidate: we compared the expression of this and a truncated gag (p17/p24) and the p24 cap ... | 2008 | 18573204 |
| skim milk enhances the preservation of thawed -80 degrees c bacterial stocks. | the results from bacterial strain recovery efforts following hurricanes katrina and rita are reported. over 90% of strains frozen in 10% skim milk were recovered whereas various recovery rates were observed for glycerol-stored stocks (56% and 94% of escherichia coli, depending upon the laboratory). these observations led to a viability comparison of streptococcus pyogenes, campylobacter jejuni, borrelia burgdorferi, salmonella enterica subsp. typhimurium, pseudomonas aeruginosa and e. coli strai ... | 2008 | 18573555 |
| recent advances in the analysis of biological particles by capillary electrophoresis. | this review covers research papers published in the years 2005-2007 that describe the application of capillary electrophoresis to the analysis of biological particles such as whole cells, subcellular organelles, viruses and microorganisms. | 2008 | 18576409 |
| evidence of recent interkingdom horizontal gene transfer between bacteria and candida parapsilosis. | to date very few incidences of interdomain gene transfer into fungi have been identified. here, we used the emerging genome sequences of candida albicans wo-1, candida tropicalis, candida parapsilosis, clavispora lusitaniae, pichia guilliermondii, and lodderomyces elongisporus to identify recent interdomain hgt events. we refer to these as ctg species because they translate the ctg codon as serine rather than leucine, and share a recent common ancestor. | 2008 | 18577206 |
| spermidine exodus and oxidation in the apoplast induced by abiotic stress is responsible for h2o2 signatures that direct tolerance responses in tobacco. | polyamines (pas) exert a protective effect against stress challenges, but their molecular role in this remains speculative. in order to detect the signaling role of apoplastic pa-derived hydrogen peroxide (h2o2) under abiotic stress, we developed a series of tobacco (nicotiana tabacum cv xanthi) transgenic plants overexpressing or downregulating apoplastic polyamine oxidase (pao; s-pao and a-pao plants, respectively) or downregulating s-adenosyl-l-methionine decarboxylase (samdc plants). upon sa ... | 2008 | 18577660 |
| expression of chlamydophila psittaci momp heat-labile toxin b subunit fusion gene in transgenic rice. | a dna fragment encoding the momp gene of chlamydophila psittaci was fused to the heat-labile toxin b subunit gene (ltb-momp) and transferred into rice callus by agrobacterium tumefaciens-mediated transformation. the ltb-momp fusion gene was detected in genomic dna from transformed rice leaves by southern blot and rt-pcr amplification. synthesis and assembly of the ltb-momp fusion protein into pentamers was detected in transformed leaf extracts by immunoblot analysis. binding of the pentamers to ... | 2008 | 18579410 |
| the linear chromosome of the plant-pathogenic mycoplasma 'candidatus phytoplasma mali'. | phytoplasmas are insect-transmitted, uncultivable bacterial plant pathogens that cause diseases in hundreds of economically important plants. they represent a monophyletic group within the class mollicutes (trivial name mycoplasmas) and are characterized by a small genome with a low gc content, and the lack of a firm cell wall. all mycoplasmas, including strains of 'candidatus (ca.) phytoplasma asteris' and 'ca. p. australiense', examined so far have circular chromosomes, as is the case for almo ... | 2008 | 18582369 |
| bridging the gap between plant and mammalian polyamine catabolism: a novel peroxisomal polyamine oxidase responsible for a full back-conversion pathway in arabidopsis. | in contrast to animals, where polyamine (pa) catabolism efficiently converts spermine (spm) to putrescine (put), plants have been considered to possess a pa catabolic pathway producing 1,3-diaminopropane, delta(1)-pyrroline, the corresponding aldehyde, and hydrogen peroxide but unable to back-convert spm to put. arabidopsis (arabidopsis thaliana) genome contains at least five putative pa oxidase (pao) members with yet-unknown localization and physiological role(s). atpao1 was recently identified ... | 2008 | 18583528 |
| imaging of the yellow cameleon 3.6 indicator reveals that elevations in cytosolic ca2+ follow oscillating increases in growth in root hairs of arabidopsis. | in tip-growing cells, the tip-high ca(2+) gradient is thought to regulate the activity of components of the growth machinery, including the cytoskeleton, ca(2+)-dependent regulatory proteins, and the secretory apparatus. in pollen tubes, both the ca(2+) gradient and cell elongation show oscillatory behavior, reinforcing the link between the two. we report that in growing root hairs of arabidopsis (arabidopsis thaliana), an oscillating tip-focused ca(2+) gradient can be resolved through imaging o ... | 2008 | 18583529 |
| the pra1 gene family in arabidopsis. | prenylated rab acceptor 1 (pra1) domain proteins are small transmembrane proteins that regulate vesicle trafficking as receptors of rab gtpases and the vacuolar soluble n-ethylmaleimide-sensitive factor attachment receptor protein vamp2. however, little is known about pra1 family members in plants. sequence analysis revealed that higher plants, compared with animals and primitive plants, possess an expanded family of pra1 domain-containing proteins. the arabidopsis (arabidopsis thaliana) pra1 (a ... | 2008 | 18583532 |
| the molecular structure of epoxide hydrolase b from mycobacterium tuberculosis and its complex with a urea-based inhibitor. | mycobacterium tuberculosis (mtb), the intracellular pathogen that infects macrophages primarily, is the causative agent of the infectious disease tuberculosis in humans. the mtb genome encodes at least six epoxide hydrolases (ehs a to f). ehs convert epoxides to trans-dihydrodiols and have roles in drug metabolism as well as in the processing of signaling molecules. herein, we report the crystal structures of unbound mtb ehb and mtb ehb bound to a potent, low-nanomolar (ic(50) approximately 19 n ... | 2008 | 18585390 |
| structural basis of the transcriptional regulation of the proline utilization regulon by multifunctional puta. | the multifunctional escherichia coli proline utilization a (puta) flavoprotein functions both as a membrane-associated proline catabolic enzyme and as a transcriptional repressor of the proline utilization genes puta and putp. to better understand the mechanism of transcriptional regulation by puta, we have mapped the put-regulatory region, determined a crystal structure of the puta ribbon-helix-helix domain (puta52, a polypeptide corresponding to residues 1-52 of e. coli puta) complexed with dn ... | 2008 | 18586269 |
| conversion of bacillus subtilis ohrr from a 1-cys to a 2-cys peroxide sensor. | ohrr proteins can be divided into two groups based on their inactivation mechanism: 1-cys (represented by bacillus subtilis ohrr) and 2-cys (represented by xanthomonas campestris ohrr). a conserved cysteine residue near the amino terminus is present in both groups of proteins and is initially oxidized to the sulfenic acid. the b. subtilis 1-cys ohrr protein is subsequently inactivated by formation of a mixed-disulfide bond with low-molecular-weight thiols or by cysteine overoxidation to sulfinic ... | 2008 | 18586944 |
| two distinct interacting classes of nuclear envelope-associated coiled-coil proteins are required for the tissue-specific nuclear envelope targeting of arabidopsis rangap. | ran gtpase plays essential roles in multiple cellular processes, including nucleocytoplasmic transport, spindle formation, and postmitotic nuclear envelope (ne) reassembly. the cytoplasmic ran gtpase activating protein rangap is critical to establish a functional rangtp/rangdp gradient across the ne and is associated with the outer surface of the ne in metazoan and higher plant cells. arabidopsis thaliana rangap association with the root tip ne requires a family of likely plant-specific nucleopo ... | 2008 | 18591351 |
| metabolic engineering of aliphatic glucosinolates in chinese cabbage plants expressing arabidopsis mam1, cyp79f1, and cyp83a1. | three arabidopsis cdnas, mam1, cyp79f1, and cyp83a1, required for aliphatic glucosinolate biosynthesis were introduced into chinese cabbage by agrobacterium tumefaciens-mediated transformation. the transgenic lines overexpressing mam1 or cyp83a1 showed wild-type phenotypes. however, all the lines overexpressing cyp79f1 displayed phenotypes different from wild type with respect to the stem thickness as well as leaf width and shape. glucosinolate contents of the transgenic plants were compared wit ... | 2008 | 18593532 |
| a novel pathway of cytochrome c biogenesis is involved in the assembly of the cytochrome b6f complex in arabidopsis chloroplasts. | we recently characterized a novel heme biogenesis pathway required for heme c(i)' covalent binding to cytochrome b6 in chlamydomonas named system iv or ccb (cofactor assembly, complex c (b6f), subunit b (petb)). to find out whether this ccb pathway also operates in higher plants and extend the knowledge of the c-type cytochrome biogenesis, we studied arabidopsis insertion mutants in the orthologs of the ccb genes. the ccb1, ccb2, and ccb4 mutants show a phenotype characterized by a deficiency in ... | 2008 | 18593701 |
| structure and mechanism of gumk, a membrane-associated glucuronosyltransferase. | xanthomonas campestris gumk (beta-1,2-glucuronosyltransferase) is a 44-kda membrane-associated protein that is involved in the biosynthesis of xanthan, an exopolysaccharide crucial for this bacterium's phytopathogenicity. xanthan also has many important industrial applications. the gumk enzyme is the founding member of the glycosyltransferase family 70 of carbohydrate-active enzymes, which is composed of bacterial glycosyltransferases involved in exopolysaccharide synthesis. no x-ray structures ... | 2008 | 18596046 |
| viral genome methylation as an epigenetic defense against geminiviruses. | geminiviruses encapsidate single-stranded dna genomes that replicate in plant cell nuclei through double-stranded dna intermediates that associate with cellular histone proteins to form minichromosomes. like most plant viruses, geminiviruses are targeted by rna silencing and encode suppressor proteins such as al2 and l2 to counter this defense. these related proteins can suppress silencing by multiple mechanisms, one of which involves interacting with and inhibiting adenosine kinase (adk), a cel ... | 2008 | 18596098 |
| a common genomic framework for a diverse assembly of plasmids in the symbiotic nitrogen fixing bacteria. | this work centres on the genomic comparisons of two closely-related nitrogen-fixing symbiotic bacteria, rhizobium leguminosarum biovar viciae 3841 and rhizobium etli cfn42. these strains maintain a stable genomic core that is also common to other rhizobia species plus a very variable and significant accessory component. the chromosomes are highly syntenic, whereas plasmids are related by fewer syntenic blocks and have mosaic structures. the pairs of plasmids p42f-prl12, p42e-prl11 and p42b-prl9 ... | 2008 | 18596979 |
| head-neck domain of arabidopsis myosin xi, mya2, fused with gfp produces f-actin patterns that coincide with fast organelle streaming in different plant cells. | the cytoskeletal mechanisms that underlie organelle transport in plants are intimately linked to acto-myosin function. this function is mediated by the attachment of myosin heads to f-actin and the binding of cargo to the tails. acto-myosin also powers vigorous cytoplasmic streaming in plant cells. class xi myosins exhibit strikingly fast velocities and may have extraordinary roles in cellular motility. studies of the structural basis of organelle transport have focused on the cargo-binding tail ... | 2008 | 18598361 |
| an in vivo gene deletion system for determining temporal requirement of bacterial virulence factors. | analysis of phenotypes associated with specific mutants has been instrumental in determining the roles of a bacterial gene in a biological process. however, this technique does not allow one to address whether a specific gene or gene set is necessary to maintain such a process once it has been established. in the study of microbial pathogenesis, it is important but difficult to determine the temporal requirement of essential pathogenic determinants in the entire infection cycle. here we report a ... | 2008 | 18599442 |
| badh2, encoding betaine aldehyde dehydrogenase, inhibits the biosynthesis of 2-acetyl-1-pyrroline, a major component in rice fragrance. | in rice (oryza sativa), the presence of a dominant badh2 allele encoding betaine aldehyde dehydrogenase (badh2) inhibits the synthesis of 2-acetyl-1-pyrroline (2ap), a potent flavor component in rice fragrance. by contrast, its two recessive alleles, badh2-e2 and badh2-e7, induce 2ap formation. badh2 was found to be transcribed in all tissues tested except for roots, and the transcript was detected at higher abundance in young, healthy leaves than in other tissues. multiple badh2 transcript leng ... | 2008 | 18599581 |
| mutations in suppressor of variegation1, a factor required for normal chloroplast translation, suppress var2-mediated leaf variegation in arabidopsis. | the arabidopsis thaliana yellow variegated2 (var2) mutant is variegated due to lack of a chloroplast ftsh-like metalloprotease (ftsh2/var2). we have generated suppressors of var2 variegation to gain insight into factors and pathways that interact with var2 during chloroplast biogenesis. here, we describe two such suppressors. suppression of variegation in the first line, tag-fn, was caused by disruption of the nuclear gene (suppressor of variegation1 [svr1]) for a chloroplast-localized homolog o ... | 2008 | 18599582 |
| tomato protein kinase 1b mediates signaling of plant responses to necrotrophic fungi and insect herbivory. | the tomato protein kinase 1 (tpk1b) gene encodes a receptor-like cytoplasmic kinase localized to the plasma membrane. pathogen infection, mechanical wounding, and oxidative stress induce expression of tpk1b, and reducing tpk1b gene expression through rna interference (rnai) increases tomato susceptibility to the necrotrophic fungus botrytis cinerea and to feeding by larvae of tobacco hornworm (manduca sexta) but not to the bacterial pathogen pseudomonas syringae. tpk1b rnai seedlings are also im ... | 2008 | 18599583 |
| viroid-induced symptoms in nicotiana benthamiana plants are dependent on rdr6 activity. | viroids are small self-replicating rnas that infect plants. how these noncoding pathogenic rnas interact with hosts to induce disease symptoms is a long-standing unanswered question. recent experimental data have led to the suggestive proposal of a pathogenic model based on the rna silencing mechanism. however, evidence of a direct relation between key components of the rna silencing pathway and symptom expression in infected plants remains elusive. to address this issue, we used a symptomatic t ... | 2008 | 18599649 |
| a role for a menthone reductase in resistance against microbial pathogens in plants. | plants elaborate a vast array of enzymes that synthesize defensive secondary metabolites in response to pathogen attack. here, we isolated the pathogen-responsive camnr1 [menthone: (+)-(3s)-neomenthol reductase] gene, a member of the short-chain dehydrogenase/reductase (sdr) superfamily, from pepper (capsicum annuum) plants. gas chromatography-mass spectrometry analysis revealed that purified camnr1 and its ortholog atsdr1 from arabidopsis (arabidopsis thaliana) catalyze a menthone reduction wit ... | 2008 | 18599651 |
| seven in absentia proteins affect plant growth and nodulation in medicago truncatula. | protein ubiquitination is a posttranslational regulatory process essential for plant growth and interaction with the environment. e3 ligases, to which the seven in absentia (sina) proteins belong, determine the specificity by selecting the target proteins for ubiquitination. sina proteins are found in animals as well as in plants, and a small gene family with highly related members has been identified in the genome of rice (oryza sativa), arabidopsis (arabidopsis thaliana), medicago truncatula, ... | 2008 | 18599652 |
| a role for atwrky23 in feeding site establishment of plant-parasitic nematodes. | during the interaction between sedentary plant-parasitic nematodes and their host, complex morphological and physiological changes occur in the infected plant tissue, finally resulting in the establishment of a nematode feeding site. this cellular transformation is the result of altered plant gene expression most likely induced by proteins injected in the plant cell by the nematode. here, we report on the identification of a wrky transcription factor expressed during nematode infection. using bo ... | 2008 | 18599655 |
| structural basis for rna-silencing suppression by tomato aspermy virus protein 2b. | the 2b proteins encoded by cucumovirus act as post-transcriptional gene silencing suppressors to counter host defence during infection. here we report the crystal structure of tomato aspermy virus 2b (tav2b) protein bound to a 19 bp small interfering rna (sirna) duplex. tav2b adopts an all alpha-helix structure and forms a homodimer to measure sirna duplex in a length-preference mode. tav2b has a pair of hook-like structures to recognize simultaneously two alpha-helical turns of a-form rna duple ... | 2008 | 18600235 |
| modeling growth and succinoglucan production by agrobacterium radiobacter ncib 9042 in batch cultures. | wild-type agrobacterium radiobacter ncib 9042 has been cultivated in batch cultures on a synthetic medium which was adapted for growth and succinoglucan production. experiments were carried out in a 4-l stirred-tank aerated reactor. glucose, biomass, polysaccharide, protein, and inorganic- and organic-nitrogen concentrations were measured, and oxygen consumption and co(2) production rates were obtained by a gas-balance technique. nitrogen balance shows that inorganic nitrogen is entirely recover ... | 1991 | 18600699 |
| identification of a cis-regulatory element by transient analysis of co-ordinately regulated genes. | transcription factors (tfs) co-ordinately regulate target genes that are dispersed throughout the genome. this co-ordinate regulation is achieved, in part, through the interaction of transcription factors with conserved cis-regulatory motifs that are in close proximity to the target genes. while much is known about the families of transcription factors that regulate gene expression in plants, there are few well characterised cis-regulatory motifs.in arabidopsis, over-expression of the myb transc ... | 2008 | 18601751 |
| enhanced soybean infection by the legume "super-virulent" agrobacterium tumefaciens strain kat23. | agrobacterium tumefaciens kat23 harbors a nopaline-type ti plasmid and is "super-virulent" to soybean (glycine max) and other leguminous plants. the right and left border sequences of the essential cis-element for t-dna transfer were removed in order to utilize the high infectivity of this strain in an agrobacterium-mediated soybean transformation system. the resulting strain, named soy2, showed no oncogenic activity. after inoculation with disarmed soy2 harboring binary vector pig121-hm and pca ... | 2008 | 18603788 |
| broad-host-range expression vectors with tightly regulated promoters and their use to examine the influence of trar and tram expression on ti plasmid quorum sensing. | experiments requiring strong repression and precise control of cloned genes can be difficult to conduct because of the relatively high basal level of expression of currently employed promoters. we report the construction of a family of vectors that contain a reengineered laci(q)-lac promoter-operator complex in which cloned genes are strongly repressed in the absence of inducer. the vectors, all based on the broad-host-range plasmid pbbr1, are mobilizable and stably replicate at moderate copy nu ... | 2008 | 18606801 |
| vv-amp1, a ripening induced peptide from vitis vinifera shows strong antifungal activity. | latest research shows that small antimicrobial peptides play a role in the innate defense system of plants. these peptides typically contribute to preformed defense by developing protective barriers around germinating seeds or between different tissue layers within plant organs. the encoding genes could also be upregulated by abiotic and biotic stimuli during active defense processes. the peptides display a broad spectrum of antimicrobial activities. their potent anti-pathogenic characteristics ... | 2008 | 18611251 |
| cytosolic and plastoglobule-targeted carotenoid dioxygenases from crocus sativus are both involved in beta-ionone release. | saffron, the processed stigma of crocus sativus, is characterized by the presence of several apocarotenoids that contribute to the color, flavor, and aroma of the spice. however, little is known about the synthesis of aroma compounds during the development of the c. sativus stigma. the developing stigma is nearly odorless, but before and at anthesis, the aromatic compound beta-ionone becomes the principal norisoprenoid volatile in the stigma. in this study, four carotenoid cleavage dioxygenase ( ... | 2008 | 18611853 |
| dolichol biosynthesis and its effects on the unfolded protein response and abiotic stress resistance in arabidopsis. | dolichols are long-chain unsaturated polyisoprenoids with multiple cellular functions, such as serving as lipid carriers of sugars used for protein glycosylation, which affects protein trafficking in the endoplasmic reticulum. the biological functions of dolichols in plants are largely unknown. we isolated an arabidopsis thaliana mutant, lew1 (for leaf wilting1), that showed a leaf-wilting phenotype under normal growth conditions. lew1 encoded a cis-prenyltransferase, which when expressed in esc ... | 2008 | 18612099 |
| sphingolipid long-chain base hydroxylation is important for growth and regulation of sphingolipid content and composition in arabidopsis. | sphingolipids are structural components of endomembranes and function through their metabolites as bioactive regulators of cellular processes such as programmed cell death. a characteristic feature of plant sphingolipids is their high content of trihydroxy long-chain bases (lcbs) that are produced by the lcb c-4 hydroxylase. to determine the functional significance of trihydroxy lcbs in plants, t-dna double mutants and rna interference suppression lines were generated for the two arabidopsis tha ... | 2008 | 18612100 |
| improvement of shikonin productivity in lithospermum erythrorhizon cell culture by alternating carbon and nitrogen feeding strategy. | stationary phase cell suspension cultures of agrobacterium tumefaciens transformed lithospermum erythrorhizon respond to additions of sucrose-rich (c-rich) medium with a 2-3-fold increase in the accumulation of shikonin derivatives and a 3-3.5-fold increase in the accumulation of soluble phenolics while showing a modest (10-30%) increase in cell concentration. conversely, the addition of nitrate-rich (n-rich) medium resulted in 25-35% increase in biomass concentration but only 2-9% increase in s ... | 1993 | 18613125 |
| mobilization of rubisco and stroma-localized fluorescent proteins of chloroplasts to the vacuole by an atg gene-dependent autophagic process. | during senescence and at times of stress, plants can mobilize needed nitrogen from chloroplasts in leaves to other organs. much of the total leaf nitrogen is allocated to the most abundant plant protein, rubisco. while bulk degradation of the cytosol and organelles in plants occurs by autophagy, the role of autophagy in the degradation of chloroplast proteins is still unclear. we have visualized the fate of rubisco, stroma-targeted green fluorescent protein (gfp) and dsred, and gfp-labeled rubis ... | 2008 | 18614709 |
| expression of dm-amp1 in rice confers resistance to magnaporthe oryzae and rhizoctonia solani. | magnaporthe oryzae and rhizoctonia solani, are among the most important pathogens of rice, severely limiting its productivity. dm-amp1, an antifungal plant defensin from dahlia merckii, was expressed in rice (oryza sativa l. sp. indica cv. pusa basmati 1) using agrobacterium tumefaciens-mediated transformation. expression levels of dm-amp1 ranged from 0.43% to 0.57% of total soluble protein in transgenic plants. it was observed that constitutive expression of dm-amp1 suppresses the growth of m. ... | 2009 | 18618285 |
| a transformation procedure for recalcitrant tomato by addressing transgenic plant-recovery limiting factors. | agrobacterium tumefaciens technology is the battle horse for tomato genetic transformation. however, tomato varieties with low regeneration capacity are very difficult to transform. in the past, tomato transformation through agrobacterium infection was focused on varieties capable of high regeneration yield, while successful transformation of low regenerable cultivars has not been reported. the genotype response to tissue culture conditions is believed to drive the frequency of regeneration of t ... | 2008 | 18618483 |
| the yeast saccharomyces cerevisiae: a versatile model system for the identification and characterization of bacterial virulence proteins. | microbial pathogens utilize complex secretion systems to deliver proteins into host cells. these effector proteins target and usurp host cell processes to promote infection and cause disease. while secretion systems are conserved, each pathogen delivers its own unique set of effectors. the identification and characterization of these effector proteins has been difficult, often limited by the lack of detectable signal sequences and functional redundancy. model systems including yeast, worms, flie ... | 2008 | 18621006 |
| excess seqa leads to replication arrest and a cell division defect in vibrio cholerae. | although most bacteria contain a single circular chromosome, some have complex genomes, and all vibrio species studied so far contain both a large and a small chromosome. in recent years, the divided genome of vibrio cholerae has proven to be an interesting model system with both parallels to and novel features compared with the genome of escherichia coli. while factors influencing the replication and segregation of both chromosomes have begun to be elucidated, much remains to be learned about t ... | 2008 | 18621898 |
| artificial septal targeting of bacillus subtilis cell division proteins in escherichia coli: an interspecies approach to the study of protein-protein interactions in multiprotein complexes. | bacterial cell division is mediated by a set of proteins that assemble to form a large multiprotein complex called the divisome. recent studies in bacillus subtilis and escherichia coli indicate that cell division proteins are involved in multiple cooperative binding interactions, thus presenting a technical challenge to the analysis of these interactions. we report here the use of an e. coli artificial septal targeting system for examining the interactions between the b. subtilis cell division ... | 2008 | 18621900 |
| the coenzyme a biosynthetic enzyme phosphopantetheine adenylyltransferase plays a crucial role in plant growth, salt/osmotic stress resistance, and seed lipid storage. | coenzyme a (coa) is an essential cofactor in the metabolism of both prokaryotic and eukaryotic organisms and a universal five-step pathway is utilized to synthesize coa from pantothenate. null mutations in two of the five steps of this pathway led to embryo lethality and therefore viable reduction-of-function mutations are required to further study its role in plant biology. in this article, we have characterized a viable arabidopsis (arabidopsis thaliana) t-dna mutant affected in the penultimat ... | 2008 | 18621975 |
| overexpression of the arabidopsis 10-kilodalton acyl-coenzyme a-binding protein acbp6 enhances freezing tolerance. | small 10-kd acyl-coenzyme a-binding proteins (acbps) are highly conserved proteins that are prevalent in eukaryotes. in arabidopsis (arabidopsis thaliana), other than the 10-kd acbp homolog (designated arabidopsis acbp6), there are five larger forms of acbps ranging from 37.5 to 73.1 kd. in this study, the cytosolic subcellular localization of arabidopsis acbp6 was confirmed by analyses of transgenic arabidopsis expressing autofluorescence-tagged acbp6 and western-blot analysis of subcellular fr ... | 2008 | 18621979 |
| a novel rna-binding protein associated with cell plate formation. | building a cell plate during cytokinesis in plant cells requires the participation of a number of proteins in a multistep process. we previously identified phragmoplastin as a cell plate-specific protein involved in creating a tubulovesicular network at the cell plate. we report here the identification and characterization of a phragmoplastin-interacting protein, phip1, in arabidopsis (arabidopsis thaliana). it contains multiple functional motifs, including a lysine-rich domain, two rna recognit ... | 2008 | 18621982 |
| combination of novel green fluorescent protein mutant tsapphire and dsred variant morange to set up a versatile in planta fret-flim assay. | förster resonance energy transfer (fret) measurements based on fluorescence lifetime imaging microscopy (flim) are increasingly being used to assess molecular conformations and associations in living systems. reduction in the excited-state lifetime of the donor fluorophore in the presence of an appropriately positioned acceptor is taken as strong evidence of fret. traditionally, cyan fluorescent protein has been widely used as a donor fluorophore in fret experiments. however, given its photolabi ... | 2008 | 18621983 |
| indian mustard aquaporin improves drought and heavy-metal resistance in tobacco. | an aquaporin cdna bjpip1 isolated from heavy-metal accumulator indian mustard (brassica juncea l.) encodes a 286-residue protein. the deduced amino acid sequence of bjpip1 with six putative transmembrane domains showed highest identity (85-99%) to pip1 subfamily members. semi-quantitative rt-pcr analysis revealed that bjpip1 transcripts were more abundantly expressed in roots compared to aerial parts of indian mustard. however, the expression of bjpip1 in leaves was up-regulated by drought, salt ... | 2008 | 18622723 |
| kinetic model of disaccharide oxidation by agrobacterium tumefaciens. | disaccharides were microbially transformed to their corresponding 3-keto-derivatives by resting cells of agrobacterium tumefaciens ncppb 396. the kinetics and yield of this highly specific oxidation depend on several factors. the oxygen concentration especially has a major influence on the production of 3-keto-derivatives and was investigated kinetically with respect to low stationary oxygen concentrations in solution. experiments showed unconventional results that conflicted with normal michael ... | 1995 | 18623455 |
| optimization of trichloroethylene degradation using soluble methane monooxygenase of methylosinus trichosporium ob3b expressed in recombinant bacteria. | by complementing cell-free extracts of pseudomonas putida f1/psmmo20 with purified soluble methane monooxygenase (smmo) components of methylosinus trichosporium ob3b, the low cloned-gene smmo activity in the recombinant strain was found to be due to incomplete activity of the hydroxylase component. to address this incomplete activity, additional smmo-expressing strains were formed by transferring mmo-containing psmmo20 and psmmo50 into various bacterial species including pseudomonads and alpha-2 ... | 1996 | 18624367 |
| the arabidopsis thaliana response regulator arr22 is a putative ahp phospho-histidine phosphatase expressed in the chalaza of developing seeds. | the arabidopsis response regulator 22 (arr22) is one of two members of a recently defined novel group of two-component system (tcs) elements. tcss are stimulus perception and response modules of prokaryotic origin, which signal by a his-to-asp phosphorelay mechanism. in plants, tcs regulators are involved in hormone response pathways, such as those for cytokinin and ethylene. while the functions of the other tcs elements in arabidopsis, such as histidine kinases (ahks), histidine-containing phos ... | 2008 | 18625081 |
| mechanism of the quorum-quenching lactonase (aiia) from bacillus thuringiensis. 1. product-bound structures. | enzymes capable of hydrolyzing n-acyl- l-homoserine lactones (ahls) used in some bacterial quorum-sensing pathways are of considerable interest for their ability to block undesirable phenotypes. most known ahl hydrolases that catalyze ring opening (ahl lactonases) are members of the metallo-beta-lactamase enzyme superfamily and rely on a dinuclear zinc site for catalysis and stability. here we report the three-dimensional structures of three product complexes formed with the ahl lactonase from b ... | 2008 | 18627129 |
| native bacterial endophytes promote host growth in a species-specific manner; phytohormone manipulations do not result in common growth responses. | all plants in nature harbor a diverse community of endophytic bacteria which can positively affect host plant growth. changes in plant growth frequently reflect alterations in phytohormone homoeostasis by plant-growth-promoting (pgp) rhizobacteria which can decrease ethylene (et) levels enzymatically by 1-aminocyclopropane-1-carboxylate (acc) deaminase or produce indole acetic acid (iaa). whether these common pgp mechanisms work similarly for different plant species has not been rigorously teste ... | 2008 | 18628963 |
| [transformation of astragalus melilotoides pall with atnhx1 gene and the expression of salinity tolerance of transformants]. | using rt-pcr method, the open reading frame (orf) of atnhx1-cdna, encoding the vacuolar na+/h+ antiportor, was cloned from arabidopsis thaliana seedlings pretreated with 100 mmol/l nacl for 24h. this orf was inserted between camv35s promoter, a omega fragment of tmv rna 5'utr and nos polya terminator in the t-dna region of a binary expression vector pnt (fig1). the recombinant plasmid, designated as pnt-atnhx1, was then transformed into agrobacterium tumefaciens lba4404. mediated by this enginee ... | 2008 | 18630600 |
| the periplasmic regulator exor inhibits exos/chvi two-component signalling in sinorhizobium meliloti. | sinorhizobium meliloti requires exos/chvi two-component signalling to establish a nitrogen-fixing symbiosis with legume hosts. the importance of exos/chvi signalling in microbe-host interactions is underscored by the requirement of exos/chvi orthologues for virulence of the related alpha-proteobacteria agrobacterium tumefaciens and brucella abortus. in s. meliloti, exos/chvi is a key regulator of gene expression for exopolysaccharide synthesis, biofilm formation, motility, nutrient utilization a ... | 2008 | 18631237 |
| eukaryotic translation initiation factor 5a is involved in pathogen-induced cell death and development of disease symptoms in arabidopsis. | eukaryotic translation initiation factor 5a (eif5a) is a highly conserved protein found in all eukaryotic kingdoms. this study demonstrates that plant eif5a is involved in the development of disease symptoms induced by a common necrotrophic bacterial phytopathogen. specifically, ateif5a-2, one of the three eif5a genes in arabidopsis (arabidopsis thaliana), is shown to regulate programmed cell death caused by infection with virulent pseudomonas syringae pv tomato dc3000 (pst dc3000). transgenic a ... | 2008 | 18633122 |
| quorum sensing in cyanobacteria: n-octanoyl-homoserine lactone release and response, by the epilithic colonial cyanobacterium gloeothece pcc6909. | quorum sensing involving acyl homoserine lactones (ahls) is a density-dependent form of intercellular communication that occurs in many different members of the group proteobacteria. however, to date, there have been few investigations of its occurrence in cyanobacteria. here, using both a bioreporter agrobacterium tumefaciens ntl4 (pzlr4) and mass spectrometry, we provide evidence of n-octanoyl homoserine lactone (c8-ahl) production in axenic cultures of the cyanobacterium gloeothece pcc6909 an ... | 2008 | 18633449 |
| application of numerical modeling for the development of optimized complex medium for d-hydantoinase production from agrobacterium radiobacter nrrl b 11291. | d-hydantoinases (e.c.3.5.2.2) are commercially valuable enzymes involved in the production of d-amino acids. however, commercial exploitation of the biological process is rare, mainly because sufficient details are not available on the efficient production of these enzymes by microorganisms. in the present study, agrobacterium radiobacter was used as the source of d-hydantoinase and its production was optimized with inexpensive carbon and nitrogen sources. the four media components selected to s ... | 1997 | 18636452 |
| detection of genetically modified canola using multiplex pcr coupled with oligonucleotide microarray hybridization. | a rapid method was developed for concurrent screening of transgenic elements in gm canola. this method utilizes a single multiplex pcr coupled with an oligonucleotide dna array capable of simultaneously detecting the 12 approved gm canola lines in canada. the assay includes construct-specific elements for identification of approved lines, common elements (e.g., camv 35s promoter, agrobacterium tumefaciens nos terminator, or nptii gene) for screening of approved or unapproved lines, a canola-spec ... | 2008 | 18636685 |
| facile immobilization of evolved agrobacterium radiobacter carbamoylase with high thermal and oxidative stability. | optically pure amino acids have been widely used as intermediates in the synthesis of antibiotics, antifungal agents, pesticides, and sweeteners. of particular importance, d- p-hydroxyphenylglycine (d-hpg) can be produced from d, l-hydroxyphenly hydantoin (d,l-hph) in a two-step reaction mediated by d-hydantoinase and n-carbamoyl- d-amino acid amidohydrolase (or carbamoylase). to make this production more industrially appealing, the carbamoylase gene from agrobacterium radiobacter nrrl b11291 cl ... | 2008 | 18636689 |
| detection and identification of bacteria intimately associated with fungi of the order sebacinales. | because of their beneficial impact on plants, the highly diverse mycorrhizal fungi grouped in the order sebacinales lay claim to high ecological and agricultural significance. here, we describe for the first time associations of sebacinoid members with bacteria. using quantitative pcr, denaturating gradient gel electrophoresis and fluorescence in situ hybridization, we detected an intimate association between piriformospora indica and rhizobium radiobacter, an alpha-proteobacterium. the stabilit ... | 2008 | 18637023 |
| enzymatic, immunological and phylogenetic characterization of brucella suis urease. | the sequenced genomes of the brucella spp. have two urease operons, ure-1 and ure-2, but there is evidence that only one is responsible for encoding an active urease. the present work describes the purification and the enzymatic and phylogenomic characterization of urease from brucella suis strain 1330. additionally, the urease reactivity of sera from patients diagnosed with brucellosis was examined. | 2008 | 18638408 |
| the state of phage psi dna in lysogenic cells of agrobacterium tumefaciens. | phage psi a temperate phage of agrobacterium tunefaciens is mutagenic, grows poorly in strains which contain a pti plasmid, and can be transferred by conjugation (d. expert and j. tourneur, 1982, j. virol., 42, 283-291). in an attempt to explain these unusual properties we undertook a study of the state of psi dna in the virion, during the lytic cycle, and in lysogenic cells. in the virions, the phage genome was found to consist of circularly permuted molecules. covalently closed circular forms ... | 1982 | 18638749 |
| c-di-gmp is an effective immunomodulator and vaccine adjuvant against pneumococcal infection. | cyclic diguanylate (c-di-gmp) is a unique bacterial intracellular signaling molecule capable of stimulating enhanced protective innate immunity against various bacterial infections. the effects of intranasal pretreatment with c-di-gmp, or intraperitoneal coadministration of c-di-gmp with the pneumolysin toxoid (pdb) or pneumococcal surface protein a (pspa) before pneumococcal challenge, were investigated in mice. we found that c-di-gmp had no significant direct short-term effect on the growth ra ... | 2008 | 18640167 |
| functional analysis of arabidopsis postprenylation caax processing enzymes and their function in subcellular protein targeting. | prenylation is a posttranslational protein modification essential for developmental processes and response to abscisic acid. following prenylation, the three c-terminal residues are proteoliticaly removed and in turn the free carboxyl group of the isoprenyl cysteine is methylated. the proteolysis and methylation, collectively referred to as caax processing, are catalyzed by ste24 endoprotease or rce1 endoprotease and by an isoprenyl cysteine methyltransferase (icmt). arabidopsis (arabidopsis tha ... | 2008 | 18641086 |
| the yebc family protein pa0964 negatively regulates the pseudomonas aeruginosa quinolone signal system and pyocyanin production. | bacterial pathogenicity is often manifested by the expression of various cell-associated and secreted virulence factors, such as exoenzymes, protease, and toxins. in pseudomonas aeruginosa, the expression of virulence genes is coordinately controlled by the global regulatory quorum-sensing systems, which includes the las and rhl systems as well as the pseudomonas quinolone signal (pqs) system. phenazine compounds are among the virulence factors under the control of both the rhl and pqs systems. ... | 2008 | 18641136 |
| induced plant defenses in the natural environment: nicotiana attenuata wrky3 and wrky6 coordinate responses to herbivory. | a plant-specific family of wrky transcription factors regulates plant responses to pathogens and abiotic stresses. here, we identify two insect-responsive wrky genes in the native tobacco nicotiana attenuata: wrky3, whose transcripts accumulate in response to wounding, and wrky6, whose wound responses are significantly amplified when fatty acid-amino acid conjugates (facs) in larval oral secretions are introduced into wounds during feeding. wrky3 is required for wrky6 elicitation, yet neither is ... | 2008 | 18641266 |
| rapid hydrolysis of quorum-sensing molecules in the gut of lepidopteran larvae. | microorganisms compete for nutrients and living space in the gut of plant-feeding insect larvae, such as spodoptera spp. their physiological activities and their organization are generally controlled or synchronised by "autoinducers", such as n-acylhomoserinelactones (ahls). due to the strongly alkaline milieu in the insect gut, the lactone ring of ahls is rapidly and spontaneously opened. further degradation to the inactive components homoserine and the acyl moiety is then achieved by a microbi ... | 2008 | 18642255 |
| functional gene-mining for salt-tolerance genes with the power of arabidopsis. | here we report on a functional gene-mining method developed to isolate stress tolerance genes without any prior knowledge of the genome or genetic mapping of the source germplasms. the feasibility of this approach was demonstrated by isolating novel salt stress tolerance genes from salt cress (thellungiella halophila), an extremophile that is adapted to a harsh saline environment and a close relative of the model plant arabidopsis thaliana. this gene-mining method is based on the expression of s ... | 2008 | 18643972 |
| involvement of rte1 in conformational changes promoting etr1 ethylene receptor signaling in arabidopsis. | ethylene is an important regulator of plant growth, development and responses to environmental stresses. arabidopsis perceives ethylene through five homologous receptors that negatively regulate ethylene responses. rte1, a novel gene conserved in plants, animals and some protists, was recently identified as a positive regulator of the etr1 ethylene receptor. here, we genetically analyze the dependence of etr1 on rte1 in order to obtain further insight into rte1 function. the function of rte1 was ... | 2008 | 18643990 |
| comprehensive analysis of single-repeat r3 myb proteins in epidermal cell patterning and their transcriptional regulation in arabidopsis. | single-repeat r3 myb transcription factors are critical components of the lateral inhibition machinery that mediates epidermal cell patterning in plants. sequence analysis of the arabidopsis genome using the blast program reveals that there are a total of six genes, including triptychon (try), caprice (cpc), trichomeless1 (tcl1), and enhancer of try and cpc 1, 2, and 3 (etc1, etc2 and etc3) encoding single-repeat r3 myb transcription factors that are approximately 50% identical to one another at ... | 2008 | 18644155 |
| expression of alfalfa mosaic virus and tobacco rattle virus coat protein genes in transgenic tobacco plants. | using the agrobacterium tumefaciens binary vector system, a chimeric gene consisting of the cauliflower mosaic virus 35 s promoter, alfalfa mosaic virus (aimv) coat protein (cp) cistron, and the nopaline synthase polyadenylation signal was integrated into the genome of nicotiana tabacum cv. samsun nn. in 70% of the transgenic tobacco plants the chimeric mrna and its translation product could be detected. cp accumulated to levels up to 0.05% of the soluble leaf protein. the accumulation was indep ... | 1987 | 18644569 |
| tsr-gfp accumulates linearly with time at cell poles, and can be used to differentiate 'old' versus 'new' poles, in escherichia coli. | summary: in escherichia coli, the chemotaxis receptor protein tsr localizes abundantly to cell poles. the current study, utilizing a tsr-gfp fusion protein and time-lapse fluorescence microscopy of individual cell lineages, demonstrates that tsr accumulates approximately linearly with time at the cell poles and that, in consequence, more tsr is present at the old pole of each cell than at its newborn pole. the rate of pole-localized tsr accumulation is large enough that old and new poles can alw ... | 2008 | 18647166 |
| genes differentially expressed in conidia and hyphae of aspergillus fumigatus upon exposure to human neutrophils. | aspergillus fumigatus is the most common etiologic agent of invasive aspergillosis in immunocompromised patients. several studies have addressed the mechanism involved in host defense but only few have investigated the pathogen's response to attack by the host cells. to our knowledge, this is the first study that investigates the genes differentially expressed in conidia vs hyphae of a. fumigatus in response to neutrophils from healthy donors as well as from those with chronic granulomatous dise ... | 2008 | 18648542 |
| functional characterization of the arabidopsis atsuc2 sucrose/h+ symporter by tissue-specific complementation reveals an essential role in phloem loading but not in long-distance transport. | atsuc2 (at1g22710) encodes a phloem-localized sucrose (suc)/h(+) symporter necessary for efficient suc transport from source tissues to sink tissues in arabidopsis (arabidopsis thaliana). atsuc2 is highly expressed in the collection phloem of mature leaves, and its function in phloem loading is well established. atsuc2, however, is also expressed strongly in the transport phloem, where its role is more ambiguous, and it has been implicated in mediating both efflux and retrieval to and from flank ... | 2008 | 18650401 |
| quorum-sensing signals in the microbial community of the cabbage white butterfly larval midgut. | the overall goal of this study was to examine the role of quorum-sensing (qs) signals in a multispecies microbial community. toward this aim, we studied qs signals produced by an indigenous member and an invading pathogen of the microbial community of the cabbage white butterfly (cwb) larval midgut (pieris rapae). as an initial step, we characterized the qs system in pantoea cwb304, which was isolated from the larval midgut. a luxi homolog, designated pani, is necessary for the production of n-a ... | 2008 | 18650927 |
| crystal structure of glutamine receptor protein from sulfolobus tokodaii strain 7 in complex with its effector l-glutamine: implications of effector binding in molecular association and dna binding. | genome analyses have revealed that members of the lrp/asnc family of transcriptional regulators are widely distributed among prokaryotes, including both bacteria and archaea. these regulatory proteins are involved in cellular metabolism in both global and specific manners, depending on the availability of the exogenous amino acid effectors. here we report the first crystal structure of glutamine receptor protein (grp) from sulfolobus tokodaii strain 7, in the ligand-free and glutamine-bound (grp ... | 2008 | 18653535 |
| rnai screen of endoplasmic reticulum-associated host factors reveals a role for ire1alpha in supporting brucella replication. | brucella species are facultative intracellular bacterial pathogens that cause brucellosis, a global zoonosis of profound importance. although recent studies have demonstrated that brucella spp. replicate within an intracellular compartment that contains endoplasmic reticulum (er) resident proteins, the molecular mechanisms by which the pathogen secures this replicative niche remain obscure. here, we address this issue by exploiting drosophila s2 cells and rna interference (rnai) technology to de ... | 2008 | 18654626 |
| complete genome sequence of the n2-fixing broad host range endophyte klebsiella pneumoniae 342 and virulence predictions verified in mice. | we report here the sequencing and analysis of the genome of the nitrogen-fixing endophyte, klebsiella pneumoniae 342. although k. pneumoniae 342 is a member of the enteric bacteria, it serves as a model for studies of endophytic, plant-bacterial associations due to its efficient colonization of plant tissues (including maize and wheat, two of the most important crops in the world), while maintaining a mutualistic relationship that encompasses supplying organic nitrogen to the host plant. genomic ... | 2008 | 18654632 |
| effects of medicago truncatula genetic diversity, rhizobial competition, and strain effectiveness on the diversity of a natural sinorhizobium species community. | we investigated the genetic diversity and symbiotic efficiency of 223 sinorhizobium sp. isolates sampled from a single mediterranean soil and trapped with four medicago truncatula lines. dna molecular polymorphism was estimated by capillary electrophoresis-single-stranded conformation polymorphism and restriction fragment length polymorphism on five loci (igs(nod), typa, virb11, avhb11, and the 16s rrna gene). more than 90% of the rhizobia isolated belonged to the sinorhizobium medicae species ( ... | 2008 | 18658290 |
| the cladosporium fulvum virulence protein avr2 inhibits host proteases required for basal defense. | cladosporium fulvum (syn. passalora fulva) is a biotrophic fungal pathogen that causes leaf mold of tomato (solanum lycopersicum). during growth in the apoplast, the fungus establishes disease by secreting effector proteins, 10 of which have been characterized. we have previously shown that the avr2 effector interacts with the apoplastic tomato cys protease rcr3, which is required for cf-2-mediated immunity. we now show that avr2 is a genuine virulence factor of c. fulvum. heterologous expressio ... | 2008 | 18660430 |
| the epip peptide of inflorescence deficient in abscission is sufficient to induce abscission in arabidopsis through the receptor-like kinases haesa and haesa-like2. | in arabidopsis thaliana, the final step of floral organ abscission is regulated by inflorescence deficient in abscission (ida): ida mutants fail to abscise floral organs, and plants overexpressing ida display earlier abscission. we show that five ida-like (idl) genes are expressed in different tissues, but plants overexpressing these genes have phenotypes similar to ida-overexpressing plants, suggesting functional redundancy. ida/idl proteins have n-terminal signal peptides and a c-terminal cons ... | 2008 | 18660431 |
| generation of selectable marker-free sheath blight resistant transgenic rice plants by efficient co-transformation of a cointegrate vector t-dna and a binary vector t-dna in one agrobacterium tumefaciens strain. | co-transformation of oryza sativa l. var. pusa basmati1 was done using an agrobacterium tumefaciens strain harbouring a single-copy cointegrate vector and a multi-copy binary vector in the same cell. the t-dna of the cointegrate vector pgv2260::pssj1 carried the hygromycin phosphotransferase (hph) and beta-glucuronidase (gus) genes. the binary vector pcam-chi11, without a plant selectable marker gene, harboured the rice chitinase (chi11) gene under maize ubiquitin promoter. co-transformation of ... | 2008 | 18663452 |
| cell-cell signaling and the agrobacterium tumefaciens ti plasmid copy number fluctuations. | the agrobacterium tumefaciens oncogenic ti plasmids replicate and segregate to daughter cells via repabc cassettes, in which repa and repb are plasmid partitioning genes and repc encodes the replication initiator protein. repabc cassettes are encountered in a growing number of plasmids and chromosomes of the alpha-proteobacteria, and findings from particular representatives of agrobacteria, rhizobia and paracoccus have began to shed light on their structure and functions. amongst repabc replicon ... | 2008 | 18664372 |
| xopd sumo protease affects host transcription, promotes pathogen growth, and delays symptom development in xanthomonas-infected tomato leaves. | we demonstrate that xopd, a type iii effector from xanthomonas campestris pathovar vesicatoria (xcv), suppresses symptom production during the late stages of infection in susceptible tomato (solanum lycopersicum) leaves. xopd-dependent delay of tissue degeneration correlates with reduced chlorophyll loss, reduced salicylic acid levels, and changes in the mrna abundance of senescence- and defense-associated genes despite high pathogen titers. subsequent structure-function analyses led to the disc ... | 2008 | 18664616 |
| cooperative activity of dna methyltransferases for maintenance of symmetrical and non-symmetrical cytosine methylation in arabidopsis thaliana. | maintenance of cytosine methylation in plants is controlled by three dna methyltransferases. met1 maintains cg methylation, and drm1/2 and cmt3 act redundantly to enforce non-cg methylation. rps, a repetitive hypermethylated dna fragment from petunia hybrida, attracts dna methylation when transferred into petunia or other species. in arabidopsis thaliana, which does not contain any rps homologues, rps transgenes are efficiently methylated in all sequence contexts. to test which dna methylation p ... | 2008 | 18665914 |
| detection of n-acyl homoserine lactones using a trai-luxcdabe-based biosensor as a high-throughput screening tool. | bacteria use n-acyl homoserine lactone (ahl) molecules to regulate the expression of genes in a density-dependent manner. several biosensors have been developed and engineered to detect the presence of all types of ahls. | 2008 | 18667064 |
| arabidopsis somatic embryogenesis receptor kinase proteins serve brassinosteroid-dependent and -independent signaling pathways. | the arabidopsis (arabidopsis thaliana) somatic embryogenesis receptor kinase (serk) genes belong to a small family of five plant receptor kinases that are involved in at least five different signaling pathways. one member of this family, brassinosteroid insensitive1 (bri1)-associated kinase1 (bak1), also known as serk3, is the coreceptor of the brassinolide (br)-perceiving receptor bri1, a function that is br dependent and partially redundant with serk1. bak1 (serk3) alone controls plant innate ... | 2008 | 18667726 |
| oxalate decarboxylase from agrobacterium tumefaciens c58 is translocated by a twin arginine translocation system. | oxalate decarboxylases (oxdcs) (e.c. 4.1.1.2) are enzymes catalyzing the conversion of oxalate to formate and co2 the oxdcs found in fungi and bacteria belong to functionally diverse protein superfamily known as the cupins. fungi-originated oxdcs are secretory enzymes. however, most bacterial oxdcs are localized in the cytosol, and may be involved in energy metabolism. in agrobacterium tumefaciens c58, a locus for a putative oxalate decarboxylase is present. in the study reported here, an enzyme ... | 2008 | 18667852 |
| architectures and biogenesis of non-flagellar protein appendages in gram-negative bacteria. | bacteria commonly expose non-flagellar proteinaceous appendages on their outer surfaces. these extracellular structures, called pill or fimbriae, are employed in attachment and invasion, biofilm formation, cell motility or protein and dna transport across membranes. over the past 15 years, the power of molecular and structural techniques has revolutionalized our understanding of the biogenesis, structure, function and mode of action of these bacterial organelles. here, we review the five known c ... | 2008 | 18668121 |
| comparative transcriptome analysis of agrobacterium tumefaciens in response to plant signal salicylic acid, indole-3-acetic acid and gamma-amino butyric acid reveals signalling cross-talk and agrobacterium--plant co-evolution. | agrobacterium has evolved sophisticated strategies to perceive and transduce plant-derived cues. recent studies have found that numerous plant signals, including salicylic acid (sa), indole-3-acetic acid (iaa) and gamma-amino butyric acid (gaba), profoundly affect agrobacterium-plant interactions. here we determine and compare the transcriptome profiles of agrobacterium in response to these three plant signals. collectively, the transcription of 103, 115 and 95 genes was significantly altered by ... | 2008 | 18671824 |
| histoplasma capsulatum at the host-pathogen interface. | histoplasma capsulatum is the most common cause of invasive fungal pulmonary disease worldwide. the interaction of h. capsulatum with a host is a complex, dynamic process. severe disease most commonly occurs in individuals with compromised immunity, and the increasing utilization of immunomodulators in medicine has revealed significant risks for reactivation disease in patients with latent histoplasmosis. fortunately, there are well developed molecular tools and excellent animal models for study ... | 2008 | 18672088 |
| efficient four fragment cloning for the construction of vectors for targeted gene replacement in filamentous fungi. | the rapid increase in whole genome fungal sequence information allows large scale functional analyses of target genes. efficient transformation methods to obtain site-directed gene replacement, targeted over-expression by promoter replacement, in-frame epitope tagging or fusion of coding sequences with fluorescent markers such as gfp are essential for this process. construction of vectors for these experiments depends on the directional cloning of two homologous recombination sequences on each s ... | 2008 | 18673530 |
| lymphoepithelioma-like carcinoma of the urinary bladder in a cow associated with bovine papillomavirus type-2. | lymphoepithelioma-like carcinoma (lelca) of the urinary bladder is reported in a 7-year-old cow that had grazed pasture rich in bracken fern and had suffered from severe intermittent haematuria from 3 to 4 years of age. on necropsy examination there were multiple haemorrhagic foci scattered over the mucosal surface of the urinary bladder. microscopically there were nests, cords and sheets of neoplastic cells infiltrating the lamina propria and muscularis propria. these had a syncytial appearance ... | 2008 | 18675990 |
| involvement of the pepper antimicrobial protein caamp1 gene in broad spectrum disease resistance. | pathogen-inducible antimicrobial defense-related proteins have emerged as key antibiotic peptides and enzymes involved in disease resistance in plants. a novel antimicrobial protein gene, caamp1 (for capsicum annuum antimicrobial protein1), was isolated from pepper (c. annuum) leaves infected with xanthomonas campestris pv vesicatoria. expression of the caamp1 gene was strongly induced in pepper leaves not only during pathogen infection but also after exposure to abiotic elicitors. the purified ... | 2008 | 18676663 |
| functional diversification of clavata3-related cle proteins in meristem maintenance in rice. | postembryonic development in plants depends on the activity of the shoot apical meristem (sam) and root apical meristem (ram). in arabidopsis thaliana, clavata signaling negatively regulates the size of the stem cell population in the sam by repressing wuschel. in other plants, however, studies of factors involved in stem cell maintenance are insufficient. here, we report that two proteins closely related to clavata3, floral organ number2 (fon2) and fon2-like cle protein1 (fcp1/os cle402), have ... | 2008 | 18676878 |
| characterization of chromosomal regions conserved in yersinia pseudotuberculosis and lost by yersinia pestis. | the transformation of the enteropathogenic bacterium yersinia pseudotuberculosis into the plague bacillus, yersinia pestis, has been accompanied by extensive genetic loss. this study focused on chromosomal regions conserved in y. pseudotuberculosis and lost during its transformation into y. pestis. an extensive pcr screening of 78 strains of the two species identified five regions (r1 to r5) and four open reading frames (orfs; orf1 to orf4) that were conserved in y. pseudotuberculosis and absent ... | 2008 | 18678673 |
| crystal structure of the agrobacterium virulence complex vire1-vire2 reveals a flexible protein that can accommodate different partners. | agrobacterium tumefaciens infects its plant hosts by a mechanism of horizontal gene transfer. this capability has led to its widespread use in artificial genetic transformation. in addition to dna, the bacterium delivers an abundant ssdna binding protein, vire2, whose roles in the host include protection from cytoplasmic nucleases and adaptation for nuclear import. in agrobacterium, vire2 is bound to its acidic chaperone vire1. when expressed in vitro in the absence of vire1, vire2 is prone to o ... | 2008 | 18678909 |
| crystallization and preliminary x-ray diffraction studies of maleylacetate reductase from rhizobium sp. strain mtp-10005. | maleylacetate reductase (ec 1.3.1.32), which catalyzes the reduction of maleylacetate to 3-oxoadipate, plays an important role in the aerobic microbial catabolism of resorcinol. the enzyme has been crystallized at 293 k by the sitting-drop vapour-diffusion method supplemented with a microseeding technique, using ammonium sulfate as the precipitating agent. the crystal belonged to the monoclinic space group c2, with unit-cell parameters a = 56.85, b = 121.13, c = 94.09 a, beta = 101.48 degrees , ... | 2008 | 18678945 |