| intragenomic diversity of rhizobium leguminosarum bv. trifolii clover nodule isolates. | abstract: background: soil bacteria from the genus rhizobium are characterized by a complex genomic architecture comprising chromosome and large plasmids. genes responsible for symbiotic interactions with legumes are usually located on one of the plasmids, named the symbiotic plasmid (psym). the plasmids have a great impact not only on the metabolic potential of rhizobia but also underlie genome rearrangements and plasticity. results: here, we analyzed the distribution and sequence variability o ... | 2011 | 21619713 |
| repabc-based replication systems of rhizobium leguminosarum bv. trifolii ta1 plasmids: incompatibility and evolutionary analyses. | soil bacteria of the genus rhizobium possess complex genomes consisting of a chromosome and in addition, often, multiple extrachromosomal replicons, which are usually equipped with repabc genes that control their replication and partition. the replication regions of four plasmids of rhizobium leguminosarum bv. trifolii ta1 (rtta1) were identified and characterized. they all contained a complete set of repabc genes. the structural diversity of the rep regions of rtta1 plasmids was demonstrated fo ... | 2011 | 21620885 |
| the celc gene, a new phylogenetic marker useful for taxonomic studies in rhizobium. | the celc gene codifies for a cellulase that fulfils a very significant role in the infection process of clover by rhizobium leguminosarum. this gene is located in the celabc operon present in the chromosome of strains representing r. leguminosarum, rhizobium etli and rhizobium radiobacter whose genomes have been completely sequenced. nevertheless, the existence of this gene in other species of the genus rhizobium had not been investigated to date. in this study, the celc gene was analysed for th ... | 2011 | 21621937 |
| the vibrio cholerae type vi secretion system: evaluating its role in the human disease cholera. | vibrio cholerae, the marine bacterium responsible for the diarrheal disease cholera, utilizes a multitude of virulence factors to cause disease. the importance of two of these factors, the toxin co-regulated pilus (tcp) and cholera toxin (ct), has been well documented for pandemic o1 and epidemic o139 serogroups. in contrast, endemic non-o1 and non-o139 serogroups can cause localized outbreaks of cholera-like illness, often in the absence of tcp and ct. one virulence mechanism used by these stra ... | 2010 | 21607085 |
| lipooligosaccharide is required for the generation of infectious elementary bodies in chlamydia trachomatis. | lipopolysaccharides (lps) and lipooligosaccharides (los) are the main lipid components of bacterial outer membranes and are essential for cell viability in most gram-negative bacteria. here we show that small molecule inhibitors of lpxc [udp-3-o-(r-3-hydroxymyristoyl)-glcnac deacetylase], the enzyme that catalyzes the first committed step in the biosynthesis of lipid a, block the synthesis of los in the obligate intracellular bacterial pathogen chlamydia trachomatis. in the absence of los, chlam ... | 2011 | 21628561 |
| competitiveness of rhizobium leguminosarum bv. trifolii strains in mixed inoculation of clover (trifolium pratense). | rhizobium leguminosarum by. trifolii (rlt) establishes beneficial root nodule symbiosis with clover. twenty rlt strains differentially marked with antibiotic-resistance markers were investigated in terms of their competitiveness and plant growth promotion in mixed inoculation of clover in laboratory experiments. the results showed that the studied strains essentially differed in competition ability. these differences seem not to be dependent on bacterial multiplication in the vicinity of roots, ... | 2011 | 21630573 |
| differential expression of pathogenicity- and virulence-related genes of xanthomonas axonopodis pv. citri under copper stress. | in this study, we used real-time quantitative pcr (rt-qpcr) to evaluate the expression of 32 genes of xanthomonas axonopodis pv. citri related to pathogenicity and virulence that are also involved in copper detoxification. nearly all of the genes were up-regulated, including copa and copb. two genes homologous to members of the type ii secretion system (xcsh and xcsc) and two involved in the degradation of plant cell wall components (pgla and pel) were the most expressed in response to an elevat ... | 2010 | 21637493 |
| multiple loci are involved in quorum quenching of autoinducer i molecules in the nitrogen-fixing symbiont (sino-) rhizobium sp. ngr234. | rhizobium sp. ngr234 is a unique α-proteobacterium (order - rhizobiales) that forms nitrogen-fixing nodules with more legumes than any other micro-symbiont. since we have previously described the complete genome sequence of ngr234, we now report on a genome wide functional analysis of the genes and enzymes involved in autoinducer i hydrolysis in this microbe. altogether we identified five cosmid clones that repeatedly gave a positive result in our function-based approach for the detection of aut ... | 2011 | 21642401 |
| maldi-tof mass spectrometry is a fast and reliable platform for identification and ecological studies of species from family rhizobiaceae. | family rhizobiaceae includes fast growing bacteria currently arranged into three genera, rhizobium, ensifer and shinella, that contain pathogenic, symbiotic and saprophytic species. the identification of these species is not possible on the basis of physiological or biochemical traits and should be based on sequencing of several genes. therefore alternative methods are necessary for rapid and reliable identification of members from family rhizobiaceae. in this work we evaluated the suitability o ... | 2011 | 21655291 |
| common ancestry and novel genetic traits of francisella novicida-like isolates from north america and australia as revealed by comparative genomic analyses. | francisella novicida is a close relative of francisella tularensis, the causative agent of tularemia. the genomes of f. novicida-like clinical isolates 3523 (australian strain) and fx1 (texas strain) were sequenced and compared to f. novicida strain u112 and f. tularensis strain schu s4. the strain 3523 chromosome is 1,945,310 bp and contains 1,854 protein-coding genes. the strain fx1 chromosome is 1,913,619 bp and contains 1,819 protein-coding genes. nucmer analyses revealed that the genomes of ... | 2011 | 21666011 |
| transcript analysis of the extended hyp-operon in the cyanobacteria nostoc sp. strain pcc 7120 and nostoc punctiforme atcc 29133. | | 2011 | 21672234 |
| the iron responsive regulator irr is required for wild-type expression of the gene encoding the heme transporter bhua in brucella abortus 2308. | irr and rira, rather than fur, serve as the major iron-responsive regulators in the a-proteobacteria. with only a few exceptions, however, the relative contributions of these transcriptional regulators to the differential expression of specific iron metabolism genes in brucella strains is unclear. the gene encoding the outer membrane heme transporter bhua exhibits maximum expression in brucella abortus 2308 during growth under iron deprived conditions, and mutational studies indicate that this p ... | 2011 | 21804001 |
| mechanisms of nickel toxicity in microorganisms. | nickel has long been known to be an important human toxicant, including having the ability to form carcinomas, but until recently nickel was believed to be an issue only to microorganisms living in nickel-rich serpentine soils or areas contaminated by industrial pollution. this assumption was overturned by the discovery of a nickel defense system (rcnr/rcna) found in microorganisms that live in a wide range of environmental niches, suggesting that nickel homeostasis is a general biological conce ... | 2011 | 21799955 |
| [bioengineering of symbiotic systems: creation of new associative symbiosis with the use of lectins on the example of tobacco and colza]. | "barbate roots" in tobacco and colza transgenic on lectin gene were obtained with the use of a wild strain of agrobacterium rhizogenes 15834 transformed with pcambia1305.1 plasmid containing the full-size lectin gene (psl) from the pisum sativum. influence of expression oflectin gene on colonization oftransgenic roots with symbiont of pea (rhizobium leguminosarum) was investigated. the number of adhered bacteria onto the roots transformed with lectin gene was 14-fold and 37-fold higher in compar ... | 2011 | 21790035 |
| the rpir-like repressor iolr regulates inositol catabolism in sinorhizobium meliloti. | sinorhizobium meliloti, the nitrogen fixing symbiont of alfalfa, has the ability to catabolize myo-, scyllo- and d-chiro-inositol. functional inositol catabolism (iol) genes are required for growth on these inositol isomers and they play a role during plant bacteria interactions. the inositol catabolism genes comprise the chromosomally encoded iola (mmsa) and the ioly(smc01163)rcdeb genes, as well as the idha gene located on the psymb plasmid. reverse transcriptase assays showed that the iolyrcd ... | 2011 | 21784930 |
| expression and localization of a rhizobium-derived cambialistic superoxide dismutase in pea (pisum sativum) nodules subjected to oxidative stress. | two phylogenetically unrelated superoxide dismutase (sod) families i.e. cuznsods and fe/mn/cambialistic sods, eliminate superoxide radicals in different locations within the plant cell. cuznsods are located within the cytosol and plastids, whilst the second family of sods, which are considered to be of bacterial origin, are usually located within organelles, such as mitochondria. we have used the ros-producer methylviologen (mv) to study sod isozymes in the indeterminate nodules on pea (pisum sa ... | 2011 | 21774575 |
| sinorhizobium fredii usda257 and s. fredii usda191, cultivar-specific and non-specific symbionts of soybean, produce distinct cell surface appendages. | sinorhizobium fredii usda257 and s. fredii usda191 are fast-growing rhizobia that form nitrogen-fixing nodules on soybean roots. in contrast to usda191, usda257 exhibits cultivar specificity and can form nodules only on primitive soybean cultivars. in response to flavonoids released from soybean roots these two rhizobia secrete nodulation outer proteins (nop) to the extracellular milieu through a type iii secretion system. in spite of the fact that nop proteins are known to regulate legume nodul ... | 2011 | 21764962 |
| an acpxl mutant in rhizobium leguminosarum bv. phaseolus lacks 27-hydroxyoctacosanoic acid in its lipid a and is developmentally delayed during symbiotic infection of the determinate nodulating host plant phaseolus vulgaris. | rhizobium leguminosarum is a gram negative bacterium that forms nitrogen fixing symbioses with compatible leguminous plants via intracellular invasion and establishes a persistent infection within host membrane derived subcellular compartments. notably, an unusual very long chain fatty acid (vlcfa) is found in the lipid a of r. leguminosarum as well as in the lipid a of the medically relevant pathogens brucella abortus, brucella melitensis, bartonella henselae, and legionellae pneumophila which ... | 2011 | 21764936 |
| modulation of rosr expression and exopolysaccharide production in rhizobium leguminosarum bv. trifolii by phosphate and clover root exudates. | the acidic exopolysaccharide (eps) secreted in large amounts by the symbiotic nitrogen-fixing bacterium rhizobium leguminosarum bv. trifolii is required for the establishment of an effective symbiosis with the host plant trifolium spp. eps biosynthesis in rhizobia is a very complex process regulated at both transcriptional and post-transcriptional levels and influenced by various nutritional and environmental conditions. the r. leguminosarum bv. trifolii rosr gene encodes a transcriptional regul ... | 2011 | 21747729 |
| identification of c4-dicarboxylate transport systems in pseudomonas aeruginosapao1. | pseudomonas aeruginosautilizes preferentially c(4)-dicarboxylates such as malate, fumarate, and succinate as carbon and energy sources. we have identified and characterized two c(4)-dicarboxylate transport (dct) systems in p. aeruginosapao1. inactivation of the dcta(pa1183) gene caused a growth defect of the strain in minimal media supplemented with succinate, fumarate or malate, indicating that dcta has a major role in dct. however, residual growth of the dctamutant in these media suggested the ... | 2011 | 21725012 |
| environment sensing and response mediated by abc transporters. | transporter proteins are one of an organism's primary interfaces with the environment. the expressed set of transporters mediates cellular metabolic capabilities and influences signal transduction pathways and regulatory networks. the functional annotation of most transporters is currently limited to general classification into families. the development of capabilities to map ligands with specific transporters would improve our knowledge of the function of these proteins, improve the annotation ... | 2011 | 21810210 |
| telling the whole story in a 10,000-genome world. | abstract: | 2011 | 21714939 |
| the conjugative plasmid of a bean-nodulating sinorhizobium fredii strain is assembled from sequences of two rhizobium plasmids and the chromosome of a sinorhizobium strain. | abstract: | 2011 | 21702991 |
| [comparison of the adaptive potential for rhizobium leguminosarum bv. viceae nodule bacterial populations isolated in natural ecosystems and agrocenoses]. | polymorphism analysis was performed in rhizobium leguminosarum bv. viceae populations isolated from geographically distant regions of ukraine and middle asia. examination of cultural, biochemical, and symbiotic traits revealed interpopulation differences, which were attributed to the difference in conditions between natural ecosystems and agrocenoses. vetch has high species diversity and is not cultivated in middle asia, and the corresponding rhizobial population displayed higher genetic diversi ... | 2011 | 21675237 |
| synthesis of microbial signaling molecules and their stereochemistry-activity relationships. | microbial signaling molecules such as autoinducers and microbial hormones play important roles in intercellular communication in microorganisms. information transfer between the individual cells of a microorganism is one of the most important biological events among them. researchers often suffer from extremely low levels of microbial signaling molecule contents, which prevent them from understanding chemistry and biology of intercellular communication in microorganisms. chemical synthesis is a ... | 2011 | 21821958 |
| dddw, a third dmsp lyase in a model roseobacter marine bacterium, ruegeria pomeroyi dss-3. | ruegeria pomeroyi dss-3 is a model roseobacter marine bacterium, particularly regarding its catabolism of dimethylsulfoniopropionate (dmsp), an abundant anti-stress molecule made by marine phytoplankton. we found a novel gene, dddw, which encodes a dmsp lyase that cleaves dmsp into acrylate plus the environmentally important volatile dimethyl sulfide (dms). mutations in dddw reduced, but did not abolish dms production. transcription of dddw was greatly enhanced by pre-growth of cells with dmsp, ... | 2011 | 21677693 |
| dddw, a third dmsp lyase in a model roseobacter marine bacterium, ruegeria pomeroyi dss-3. | ruegeria pomeroyi dss-3 is a model roseobacter marine bacterium, particularly regarding its catabolism of dimethylsulfoniopropionate (dmsp), an abundant anti-stress molecule made by marine phytoplankton. we found a novel gene, dddw, which encodes a dmsp lyase that cleaves dmsp into acrylate plus the environmentally important volatile dimethyl sulfide (dms). mutations in dddw reduced, but did not abolish dms production. transcription of dddw was greatly enhanced by pre-growth of cells with dmsp, ... | 2011 | 21677693 |
| comparative genome analysis and genome-guided physiological analysis of roseobacter litoralis. | roseobacter litoralis och149, the type species of the genus, and roseobacter denitrificans och114 were the first described organisms of the roseobacter clade, an ecologically important group of marine bacteria. both species were isolated from seaweed and are able to perform aerobic anoxygenic photosynthesis. | 2011 | 21693016 |
| the bradyrhizobium japonicum frcb gene encodes a diheme ferric reductase. | iron utilization by bacteria in aerobic environments involves uptake as a ferric chelate from the environment, followed by reduction to the ferrous form. ferric iron reduction is poorly understood in most bacterial species. here, we identified bradyrhizobium japonicum frcb (bll3557) as a gene adjacent to, and coregulated with, the pyor gene (blr3555) encoding the outer membrane receptor for transport of a ferric pyoverdine. frcb is a membrane-bound, diheme protein, characteristic of eukaryotic f ... | 2011 | 21705608 |
| genome data mining and soil survey for the novel group 5 [nife]-hydrogenase to explore the diversity and ecological importance of presumptive high-affinity h2-oxidizing bacteria. | streptomyces soil isolates exhibiting the unique ability to oxidize atmospheric h(2) possess genes specifying a putative high-affinity [nife]-hydrogenase. this study was undertaken to explore the taxonomic diversity and the ecological importance of this novel functional group. we propose to designate the genes encoding the small and large subunits of the putative high-affinity hydrogenase hhys and hhyl, respectively. genome data mining revealed that the hhyl gene is unevenly distributed in the p ... | 2011 | 21742924 |
| nod factors stimulate seed germination and promote growth and nodulation of pea and vetch under competitive conditions. | nod factors are lipochitooligosaccharide (lco) produced by soil bacteria commonly known as rhizobia acting as signals for the legume plants to initiate symbiosis. nod factors trigger early symbiotic responses in plant roots and initiate the development of specialized plant organs called nodules, where biological nitrogen fixation takes place. here, the effect of specific lco originating from flavonoid induced rhizobium leguminosarum bv. viciae gr09 culture was studied on germination, plant growt ... | 2011 | 21723717 |
| Biochemical and Mutational Studies of the Bacillus cereus CECT 5050T Formamidase Support the Existence of a C-E-E-K Tetrad in Several Members of the Nitrilase Superfamily. | Formamidases (EC 3.5.1.49) are poorly characterized proteins. In spite of this scarce knowledge, ammonia has been described as playing a central role in the pathogenesis of human pathogens such as Helicobacter pylori, for which formamidase has been shown to participate in the nitrogen metabolic pathway. Sequence analysis has revealed that at least two different groups of formamidases are classified as EC 3.5.1.49: on the one hand, the derivatives of the FmdA-AmdA superfamily, which are the best ... | 2011 | 21705545 |
| Co-ordination of quorum-sensing regulation in Rhizobium leguminosarum by induction of an anti-repressor. | Analysis of quorum-sensing (QS) regulation in Rhizobium leguminosarum revealed an unusual type of gene regulation that relies on the population density-dependent accumulation of an anti-repressor. The cinS gene, which is co-transcribed with the N-acyl-homoserine-lactone synthase gene cinI, is required to fully induce rhiR and raiR, whose products, together with their partner AHL synthases, regulate other genes in a QS-regulated hierarchy. Purified CinS bound to the R.ÔÇâleguminosarum transcripti ... | 2011 | 21732996 |
| Biological activity of (lipo)polysaccharides of the exopolysaccharide-deficient mutant Rt120 derived from Rhizobium leguminosarum bv. trifolii strain TA1. | Lipopolysaccharides (LPS) from Rhizobium leguminosarum biovar trifolii TA1 (RtTA1) and its mutant Rt120 in the pssB?pssA intergenic region as well as degraded polysaccharides (DPS) derived from the LPS were elucidated in terms of their chemical composition and biological activities. The polysaccharide portions were examined by methylation analysis, MALDI-TOF mass spectrometry, and (1)H NMR spectroscopy. A high molecular mass carbohydrate fraction obtained from Rt120 DPS by Sephadex G-50 gel chro ... | 2011 | 21999546 |
| reproducible hairy root transformation and spot-inoculation methods to study root symbioses of pea. | abstract: pea has lagged behind other model legumes in the molecular study of nodulation and mycorrhizae-formation because of the difficulty to transform its roots and its poor growth on agar plates. here we describe for pea 1) a transformation technique which permits the complementation of two known non-nodulating pea mutants, 2) a rhizobial inoculation method which allows the study of early cellular events giving rise to nodule primordia, and 3) a targeted fungal inoculation method which allow ... | 2011 | 22172023 |
| separate inputs modulate phosphorylation-dependent and -independent type vi secretion activation. | productive intercellular delivery of cargo by secretory systems requires exquisite temporal and spatial choreography. our laboratory has demonstrated that the haemolysin co-regulated secretion island i (hsi-i)-encoded type vi secretion system (h1-t6ss) of pseudomonas aeruginosa transfers effector proteins to other bacterial cells. the activity of these effectors requires cell contact-dependent delivery by the secretion apparatus, and thus their export is highly repressed under planktonic growth ... | 2011 | 22017253 |
| Characterization of the galacturonosyl transferase genes rgtA, B, C, D, and E responsible for lipopolysaccharide synthesis in the nitrogen-fixing endosymbiont Rhizobium leguminosarum: Lipopolysaccharide core and lipid A galacturonosyl residues confer membrane stability. | Rhizobium lipopolysaccharide (LPS) contains four terminally linked galacturonic acid (GalA) residues: one attached to the lipid A and three attached to the core oligosaccharide moiety. Attachment of the GalA residues requires the lipid donor dodecaprenyl-phosphate GalA (Dod-P-GalA) which is synthesized by the GalA transferase (GalAT) RgtE reported here. The galacturonosyl transferases (GalATs) RgtA, B, and C utilize Dod-P-GalA to attach GalAs on the LPS core region and RgtD attaches GalA to the ... | 2011 | 22110131 |
| Characterization of the galacturonosyl transferase genes rgtA, B, C, D, and E responsible for lipopolysaccharide synthesis in the nitrogen-fixing endosymbiont Rhizobium leguminosarum: Lipopolysaccharide core and lipid A galacturonosyl residues confer membrane stability. | Rhizobium lipopolysaccharide (LPS) contains four terminally linked galacturonic acid (GalA) residues: one attached to the lipid A and three attached to the core oligosaccharide moiety. Attachment of the GalA residues requires the lipid donor dodecaprenyl-phosphate GalA (Dod-P-GalA) which is synthesized by the GalA transferase (GalAT) RgtE reported here. The galacturonosyl transferases (GalATs) RgtA, B, and C utilize Dod-P-GalA to attach GalAs on the LPS core region and RgtD attaches GalA to the ... | 2011 | 22110131 |
| mads-box transcription factor mbx2/pvg4 regulates invasive growth and flocculation by inducing gsf2+ expression in fission yeast. | the fission yeast schizosaccharomyces pombe exhibits invasive growth and nonsexual flocculation in response to nitrogen limitation. gsf2, a flocculin of fission yeast, is required for not only nonsexual flocculation but also invasive growth through recognition of galactose residues on cell-surface glycoconjugates. we found that pyruvylation negatively regulates nonsexual flocculation by capping the galactose residues of n-linked galactomannan. we investigated whether pyruvylation also regulates ... | 2011 | 22180499 |
| Mammalian ACSF3 protein is a malonyl-CoA synthetase that supplies the chain extender units for mitochondrial fatty acid synthesis. | The objective of this study was to identify a source of intramitochondrial malonyl-CoA that could be used for de novo fatty acid synthesis in mammalian mitochondria. Because mammalian mitochondria lack an acetyl-CoA carboxylase capable of generating malonyl-CoA inside mitochondria, the possibility that malonate could act as a precursor was investigated. Although malonyl-CoA synthetases have not been identified previously in animals, interrogation of animal protein sequence databases identified c ... | 2011 | 21846720 |
| Comparative genomics of the type VI secretion systems of Pantoea and Erwinia species reveals the presence of putative effector islands that may be translocated by the VgrG and Hcp proteins. | ABSTRACT: | 2011 | 22115407 |
| A plant arabinogalactan-like glycoprotein promotes a novel type of polar surface attachment by Rhizobium leguminosarum. | Rhizobium leguminosarum biovar viciae can attach to the roots of legume and non-legume plants. We wanted to determine if root exudates could affect in vitro surface attachment in a confocal microscopy assay. Root exudate from peas, other legumes, wheat and Arabidopsis, induced R.l. viciae to attach end-on (in a polar manner) to glass in hexagonal close packed arrays, rather than attaching along their long axis. This did not involve a reorientation, but was probably due to altered growth. The pol ... | 2011 | 21995765 |
| Biosynthesis of UDP-glucuronic acid and UDP-galacturonic acid in Bacillus cereus subsp. cytotoxis NVH 391-98. | The food borne pathogen Bacillus cereus produces uronic acid-containing glycans that are secreted in a shielding biofilm environment, and certain alkaliphilic Bacillus deposit uronate-glycan polymers in the cell wall when adapting to alkaline environments. The source of these acidic sugars is unknown and, in the present study, we describe the functional identification of an operon in Bacillus cerues subsp. cytotoxis NVH 391-98 that comprises genes involved in the synthesis of UDP-uronic acids in ... | 2012 | 22023070 |
| Biosynthesis of UDP-glucuronic acid and UDP-galacturonic acid in Bacillus cereus subsp. cytotoxis NVH 391-98. | The food borne pathogen Bacillus cereus produces uronic acid-containing glycans that are secreted in a shielding biofilm environment, and certain alkaliphilic Bacillus deposit uronate-glycan polymers in the cell wall when adapting to alkaline environments. The source of these acidic sugars is unknown and, in the present study, we describe the functional identification of an operon in Bacillus cerues subsp. cytotoxis NVH 391-98 that comprises genes involved in the synthesis of UDP-uronic acids in ... | 2012 | 22023070 |
| Structure-function analysis of HsiF, a gp25-like component of the type VI secretion system, in Pseudomonas aeruginosa. | Bacterial pathogens use a range of protein secretion systems to colonize their host. One recent addition to this arsenal is the type VI secretion system (T6SS), which is found in many Gram-negative bacteria. The T6SS involves 12-15 components, including a ClpV-like AAA(+) ATPase. Moreover, the VgrG and Hcp components have been proposed to form a puncturing device, based on structural similarity to the tail spike components gp5/gp27 and the tail tube component gp19 of the T4 bacteriophage, respec ... | 2011 | 21873404 |
| Genomes and Virulence Factors of Novel Bacterial Pathogens Causing Bleaching Disease in the Marine Red Alga Delisea pulchra. | Nautella sp. R11, a member of the marine Roseobacter clade, causes a bleaching disease in the temperate-marine red macroalga, Delisea pulchra. To begin to elucidate the molecular mechanisms underpinning the ability of Nautella sp. R11 to colonize, invade and induce bleaching of D. pulchra, we sequenced and analyzed its genome. The genome encodes several factors such as adhesion mechanisms, systems for the transport of algal metabolites, enzymes that confer resistance to oxidative stress, cytolys ... | 2011 | 22162749 |
| plasmid localization and organization of melamine degradation genes in rhodococcus sp. strain mel. | rhodococcus sp. strain mel was isolated from soil by enrichment and grew in minimal medium with melamine as the sole n source with a doubling time of 3.5 h. stoichiometry studies showed that all six nitrogen atoms of melamine were assimilated. the genome was sequenced by roche 454 pyrosequencing to 13x coverage and a 22.3 kb dna region was found to contain a homolog to the melamine deaminase gene trza. mutagenesis studies showed that the cyanuric acid hydrolase and biuret hydrolase genes were cl ... | 2011 | 22210223 |
| A New Family of Biuret Hydrolases Involved in S-Triazine Ring Metabolism. | Biuret is an intermediate in the bacterial metabolism of s-triazine ring compounds and is occasionally used as a ruminant feed supplement. We used bioinformatics to identify a biuret hydrolase, an enzyme that has previously resisted efforts to stabilize, purify and characterize. This newly discovered enzyme is a member of the cysteine hydrolase superfamily, a family of enzymes previously not found to be involved in s-triazine metabolism. The gene from Rhizobium leguminosarum bv. viciae strain 38 ... | 2011 | 21897878 |
| Global Transcriptomic and Proteomic Responses of Dehalococcoides ethenogenes Strain 195 to Fixed Nitrogen Limitation. | Bacteria of the genus Dehalococcoides play an important role in the reductive dechlorination of chlorinated ethenes. A systems level approach was taken in this study to examine the global transcriptomic and proteomic responses of exponentially growing D. ethenogenes strain 195 to fixed nitrogen limitation (FNL) as dechlorination activity and cell yield both decrease during FNL. As expected, the nitrogen-fixing (nif) genes were differentially up-regulated in the transcriptome and proteome of stra ... | 2011 | 22179257 |
| sinorhizobium meliloti chea complexed with ches exhibits enhanced binding to chey1 resulting in accelerated chey1-p dephosphorylation. | retrophosphorylation of the histidine kinase chea in the chemosensory transduction chain is a widespread mechanism for efficient dephosphorylation of the activated response regulator. first discovered in sinorhizobium meliloti, the main response regulator chey2-p shuttles its phosphoryl group back to chea, while a second response regulator, chey1, serves as sink for surplus phosphoryl groups from chea-p. we have identified a new component in this phospho-relay system, a small 97-aa protein, name ... | 2011 | 22194454 |
| mur regulates the gene encoding the manganese transporter mnth in brucella abortus 2308. | mnth is the only high-affinity manganese transporter identified in brucella. a previous study showed that mnth is required for the wild-type virulence of brucella abortus 2308 in mice (anderson es, et al., infect. immun. 77:3466-3474, 2009) and indicated that the mnth gene is regulated in a manganese-responsive manner in this strain by a mur homolog. in the study presented here, the transcriptional start site for mnth in b. abortus 2308 was determined by primer extension analysis. specific inter ... | 2011 | 22101848 |
| drosophila melanogaster as an animal model for the study of pseudomonas aeruginosa biofilm infections in vivo. | pseudomonas aeruginosa is an opportunistic pathogen capable of causing both acute and chronic infections in susceptible hosts. chronic p. aeruginosa infections are thought to be caused by bacterial biofilms. biofilms are highly structured, multicellular, microbial communities encased in an extracellular matrix that enable long-term survival in the host. the aim of this research was to develop an animal model that would allow an in vivo study of p. aeruginosa biofilm infections in a drosophila me ... | 2011 | 21998591 |
| contribution of nfp lysm domains to the recognition of nod factors during the medicago truncatula/sinorhizobium meliloti symbiosis. | the root nodule nitrogen fixing symbiosis between legume plants and soil bacteria called rhizobia is of great agronomical and ecological interest since it provides the plant with fixed atmospheric nitrogen. the establishment of this symbiosis is mediated by the recognition by the host plant of lipo-chitooligosaccharides called nod factors (nfs), produced by the rhizobia. this recognition is highly specific, as precise nf structures are required depending on the host plant. here, we study the imp ... | 2011 | 22087221 |
| protein domain of unknown function 3233 is a translocation domain of autotransporter secretory mechanism in gamma proteobacteria. | vibrio cholerae, the enteropathogenic gram negative bacteria is one of the main causative agents of waterborne diseases like cholera. about 1/3(rd) of the organism's genome is uncharacterised with many protein coding genes lacking structure and functional information. these proteins form significant fraction of the genome and are crucial in understanding the organism's complete functional makeup. in this study we report the general structure and function of a family of hypothetical proteins, dom ... | 2011 | 22073138 |
| mechanistic and structural studies of the n-hydroxylating flavoprotein monooxygenases. | the n-hydroxylating flavoprotein monooxygenases are siderophore biosynthetic enzymes that catalyze the hydroxylation of the sidechain amino-group of ornithine or lysine or the primary amino-group of putrescine. this hydroxylated product is subsequently formylated or acylated and incorporated into the siderophore. importantly, the modified amino-group is a hydroxamate and serves as an iron chelating moiety in the siderophore. this review describes recent work to characterize the ornithine hydroxy ... | 2011 | 21871647 |
| natural variation in host-specific nodulation of pea is associated with a haplotype of the sym37 lysm-type receptor-like kinase. | rhizobium leguminosarum bv. viciae, which nodulates pea and vetch, makes a mixture of secreted nodulation signals (nod factors) carrying either a c18:4 or a c18:1 n-linked acyl chain. mutation of node blocks the formation of the c18:4 acyl chain, and node mutants, which produce only c18:1-containing nod factors, are less efficient at nodulating pea. however, there is significant natural variation in the levels of nodulation of different pea cultivars by a node mutant of r. leguminosarum bv. vici ... | 2011 | 21995800 |
| how good is the turbid medium-based approach for accounting for light partitioning in contrasted grass--legume intercropping systems? | most studies dealing with light partitioning in intercropping systems have used statistical models based on the turbid medium approach, thus assuming homogeneous canopies. however, these models could not be directly validated although spatial heterogeneities could arise in such canopies. the aim of the present study was to assess the ability of the turbid medium approach to accurately estimate light partitioning within grass-legume mixed canopies. | 2011 | 21865218 |
| a simple method to evaluate the number of bradyrhizobia on soybean seeds and its implication on inoculant quality control. | abstract: soybean seeds are non-sterile and their bacterial population interferes with the enumeration of beneficial bacteria, making it difficult to assess survival under different conditions. within this context, the principal aims of this work were: (1) to improve a selective media for the enumeration of b. japonicum recovered from inoculated soybean seeds; (2) to establish the most representative mathematical function for b. japonicum mortality on soybean seeds after inoculation; (3) to eval ... | 2011 | 21906377 |
| characterization of rhizobia from legumes of agronomic interest grown in semi-arid areas of central spain relates genetic differences to soil properties. | a study of symbiotic bacteria from traditional agricultural legumes from central spain was performed to create a collection of rhizobia from soils differing in physicochemical, analytical and/or agroecological properties which could be well-adapted to the environmental conditions of this region, and be used for sustainable agricultural practices. thirty-six isolates were obtained from root-nodules of fifteen legume species (including cicer arietinum, lathyrus sativus, lens culinaris, lupinus spp ... | 2011 | 21953333 |
| production of 7-o-methyl aromadendrin, a medicinally valuable flavonoid, in escherichia coli. | 7-o-methyl aromadendrin (7-oma) is an aglycone moiety of one of the important flavonoid-glycosides found in several plants such as populus alba and eucalyptus maculata with various medicinal applications. to produce such valuable natural flavonoids in large quantity, e. coli cell factory has been developed to employ various plant biosynthetic pathways. here, we report the generation of 7-oma from its precursor p-coumaric acid in e. coli for the first time. primarily, naringenin (nrn) (flavanone) ... | 2011 | 22101053 |
| the superoxide dismutase soda is targeted to the periplasm in a seca-dependent manner by a novel mechanism. | the manganese/iron-type superoxide dismutase (soda) of rhizobium leguminosarum bv. viciae 3841 is exported to the periplasm of r. l. bv. viciae and escherichia coli. however, it does not possess a hydrophobic cleaved n-terminal signal peptide typically present in soluble proteins exported by the sec-dependent (sec) pathway or the twin-arginine translocation (tat) pathway. a tatc mutant of r. l. bv. viciae exported soda to the periplasm, ruling out export of soda as a complex with a tat substrate ... | 2011 | 21854464 |
| protection of sinorhizobium against host cysteine-rich antimicrobial peptides is critical for symbiosis. | sinorhizobium meliloti differentiates into persisting, nitrogen-fixing bacteroids within root nodules of the legume medicago truncatula. nodule-specific cysteine-rich antimicrobial peptides (ncr amps) and the bacterial baca protein are essential for bacteroid development. however, the bacterial factors central to the ncr amp response and the in planta role of baca are unknown. we investigated the hypothesis that baca is critical for the bacterial response towards ncr amps. we found that baca was ... | 2011 | 21990963 |
| Genomic lineages of Rhizobium etli revealed by the extent of nucleotide polymorphisms and low recombination. | Most of the DNA variations found in bacterial species are in the form of single nucleotide polymorphisms (SNPs), but there is some debate regarding how much of this variation comes from mutation versus recombination. The nitrogen-fixing symbiotic bacteria Rhizobium etli is highly variable in both genomic structure and gene content. However, no previous report has provided a detailed genomic analysis of this variation at nucleotide level or the role of recombination in generating diversity in thi ... | 2011 | 22004448 |
| arabitol metabolism of corynebacterium glutamicum and its regulation by atlr. | expression profiling of corynebacterium glutamicum in comparison to a derivative deficient of the transcriptional regulator atlr (previously known as sugr or mtlr) revealed eight genes showing more than fourfold higher mrna levels in the mutant. four of these are located in direct vicinity of the atlr gene, i.e., xylb, rbtt, mtld, and sixa, annotated as encoding xylulokinase, ribitol transporter, mannitol 2-dehydrogenase, and phosphohistidine phosphatase, respectively. transcriptional analysis i ... | 2011 | 22178972 |
| Identification of a novel gene for biosynthesis of a bacteroid-specific electron carrier menaquinone. | Ubiquinone (UQ) has been considered as an electron mediator in electron transfer that generates ATP in Rhizobium under both free-living and symbiosis conditions. When mutated, the dmtH gene has a symbiotic phenotype of forming ineffective nodules on Astragalus sinicus. The gene was isolated from a Mesorhizobium huakuii 7653R transposon-inserted mutant library. The DNA sequence and conserved protein domain analyses revealed that dmtH encodes demethylmenaquinone (DMK) methyltransferase, which cata ... | 2011 | 22194970 |
| role for rhizobium rhizogenes k84 cell envelope polysaccharides in surface interactions. | rhizobium rhizogenes strain k84 is a commercial biocontrol agent used worldwide to control crown gall disease. the organism binds tightly to polypropylene substrate and efficiently colonizes root surfaces as complex, multilayered biofilms. a genetic screen identified two mutants in which these surface interactions were affected. one of these mutants failed to attach and form biofilms on the abiotic surface; although, interestingly, it exhibited normal biofilm formation on the biological root tip ... | 2011 | 22210213 |
| atomic force microscopy of a ctpa mutant in rhizobium leguminosarum reveals surface defects linking ctpa function to biofilm formation. | atomic force microscopy was used to investigate the surface ultrastructure, adhesive properties and biofilm formation of rhizobium leguminosarum and a ctpa mutant strain. the surface ultrastructure of wild-type r. leguminosarum consists of tightly packed surface subunits, whereas the ctpa mutant has much larger subunits with loose lateral packing. the ctpa mutant strain is not capable of developing fully mature biofilms, consistent with its altered surface ultrastructure, greater roughness and s ... | 2011 | 21852352 |
| Biogeography of symbiotic and other endophytic bacteria isolated from medicinal Glycyrrhiza species in China. | A total of 159 endophytic bacteria were isolated from surface-sterilized root nodules of wild perennial Glycyrrhiza legumes growing on 40 sites in central and northwestern China. Amplified fragment length polymorphism (AFLP) genomic fingerprinting and sequencing of partial 16S rRNA genes revealed that the collection mainly consisted of Mesorhizobium, Rhizobium, Sinorhizobium, Agrobacterium and Paenibacillus species. Based on symbiotic properties with the legume hosts Glycyrrhiza uralensis and Gl ... | 2011 | 22066910 |
| Mutation of the sensor kinase chvG in Rhizobium leguminosarum negatively impacts cellular metabolism, outer membrane stability, and symbiosis. | Two component signal transduction systems (TCS) are a main strategy used by bacteria to sense and adapt to changes in their environment. In the legume symbiont Rhizobium leguminosarum biovar viciae VF39, mutation of the histidine kinase, chvG, caused a number of pleiotropic phenotypes. ChvG mutants are unable to grow on proline, glutamate, histidine, or arginine as the sole carbon source. The chvG mutant secreted lower amounts of acidic and neutral surface polysaccharides, and accumulated abnorm ... | 2011 | 22155778 |
| PATRIC: the comprehensive bacterial bioinformatics resource with a focus on human pathogenic species. | Funded by the National Institute of Allergy and Infectious Diseases, the Pathosystems Resource Integration Center (PATRIC) is a genomics-centric relational database and bioinformatics resource designed to assist scientists in infectious-disease research. Specifically, PATRIC provides scientists with (i) a comprehensive bacterial genomics database, (ii) a plethora of associated data relevant to genomic analysis, and (iii) an extensive suite of computational tools and platforms for bioinformatics ... | 2011 | 21896772 |
| the rhizome of reclinomonas americana, homo sapiens, pediculus humanus and saccharomyces cerevisiae mitochondria. | mitochondria are thought to have evolved from eubacteria-like endosymbionts; however, the origin of the mitochondrion remains a subject of debate. in this study, we investigated the phenomenon of chimerism in mitochondria to shed light on the origin of these organelles by determining which species played a role in their formation. we used the mitochondria of four distinct organisms, reclinomonas americana, homo sapiens, saccharomyces cerevisiae and multichromosome pediculus humanus, and attempte ... | 2011 | 22014084 |
| modulation of metabolism and switching to biofilm prevail over exopolysaccharide production in the response of rhizobium alamii to cadmium. | heavy metals such as cadmium (cd(2+)) affect microbial metabolic processes. consequently, bacteria adapt by adjusting their cellular machinery. we have investigated the dose-dependent growth effects of cd(2+) on rhizobium alamii, an exopolysaccharide (eps)-producing bacterium that forms a biofilm on plant roots. adsorption isotherms show that the eps of r. alamii binds cadmium in competition with calcium. a metabonomics approach based on ion cyclotron resonance fourier transform mass spectrometr ... | 2011 | 22096497 |
| A genetic discontinuity in root-nodulating bacteria of cultivated pea in the Indian trans-Himalayas. | Evolutionary relationships of 120 root-nodulating bacteria isolated from the nodules of Pisum sativum cultivated at 22 different locations of the trans-Himalayan valleys of Lahaul and Spiti in the state of Himachal Pradesh of India were studied using 16S rRNA gene PCR-RFLP, ERIC-PCR, sequencing of 16S rRNA, atpD, recA, nodC and nifH genes, carbon-source utilization pattern (BIOLOG™), and whole-cell fatty acid profiling. The results demonstrated that all isolates belonged to Rhizobium leguminosar ... | 2012 | 22092487 |
| comparative characterization of fungal anthracenone and naphthacenedione biosynthetic pathways reveals an α-hydroxylation-dependent claisen-like cyclization catalyzed by a dimanganese thioesterase. | the linear tetracyclic tan-1612 (1) and bms-192548 (2) were isolated from different filamentous fungal strains and have been examined as potential neuropeptide y and neurokinin-1 receptor antagonists, respectively. although the biosynthesis of fungal aromatic polyketides has attracted much interest in recent years, the biosynthetic mechanism for such naphthacenedione-containing products has not been established. using a targeted genome mining approach, we first located the ada gene cluster respo ... | 2011 | 21866960 |
| adaptation of rhizobium leguminosarum to pea, alfalfa and sugar beet rhizospheres investigated by comparative transcriptomics. | abstract: background: the rhizosphere is the microbe-rich zone around plant roots and is a key determinant of the biosphere's productivity. comparative transcriptomics was used to investigate general and plant-specific adaptations during rhizosphere colonization. rhizobium leguminosarum biovar viciae was grown in the rhizospheres of pea (its legume nodulation host), alfalfa (a non-host legume) and sugar beet (non-legume). gene expression data were compared to metabolic and transportome maps to ... | 2011 | 22018401 |
| Environmental signals and regulatory pathways that influence exopolysaccharide production in rhizobia. | Rhizobia are Gram-negative bacteria that can exist either as free-living bacteria or as nitrogen-fixing symbionts inside root nodules of leguminous plants. The composition of the rhizobial outer surface, containing a variety of polysaccharides, plays a significant role in the adaptation of these bacteria in both habitats. Among rhizobial polymers, exopolysaccharide (EPS) is indispensable for the invasion of a great majority of host plants which form indeterminate-type nodules. Various functions ... | 2011 | 22174640 |
| Substitutions in the BamA ß-Barrel Domain Overcome the Conditional Lethal Phenotype of a {Delta}bamB {Delta}bamE Strain of Escherichia coli. | BamA interacts with the BamBCDE lipoproteins, and together they constitute the essential ß-barrel assembly machine (BAM) of Escherichia coli. The simultaneous absence of BamB and BamE confers a conditional lethal phenotype and a severe ß-barrel outer membrane protein (OMP) biogenesis defect. Without BamB and BamE, wild-type BamA levels are significantly reduced, and the folding of the BamA ß-barrel, as assessed by the heat-modifiability assay, is drastically compromised. Single-amino-acid substi ... | 2012 | 22037403 |
| Field monitoring of plant-growth-promoting rhizobacteria by colony immunoblotting. | Inoculant plant-growth-promoting bacteria are emerging as an important component of sustainable agriculture. There is a need to develop inexpensive methods for enumerating these organisms after their application in the field, to better understand their survival and impacts on yields. Immunoblotting is one potential method to measure viable cells, but the high cost of the conventionally used nylon membranes makes this method prohibitive. In this study, less expensive alternative materials such as ... | 2011 | 22017658 |
| contribution of the lipopolysaccharide to resistance of shigella flexneri 2a to extreme acidity. | shigella flexneri is endemic in most underdeveloped countries, causing diarrheal disease and dysentery among young children. in order to reach its target site, the colon, shigella must overcome the acid environment of the stomach. shigella is able to persist in this stressful environment and, because of this ability it can initiate infection following the ingestion of very small inocula. thus, acid resistance is considered an important virulence trait of this bacterium. it has been reported that ... | 2011 | 21984920 |
| wide variation in antibiotic resistance proteins identified by functional metagenomic screening of a soil dna library. | most genes for antibiotic resistance present in soil microbes remain unexplored because most environmental microbes cannot be cultured. only recently has the identification of these genes become feasible through the use of culture-independent methods. we screened a soil metagenomic dna library in an escherichia coli host for genes that can confer resistance to kanamycin, gentamicin, rifampin, trimethoprim, chloramphenicol, or tetracycline. the screen revealed 41 genes that encode novel protein v ... | 2012 | 22247132 |
| azospirillum genomes reveal transition of bacteria from aquatic to terrestrial environments. | fossil records indicate that life appeared in marine environments ∼3.5 billion years ago (gyr) and transitioned to terrestrial ecosystems nearly 2.5 gyr. sequence analysis suggests that "hydrobacteria" and "terrabacteria" might have diverged as early as 3 gyr. bacteria of the genus azospirillum are associated with roots of terrestrial plants; however, virtually all their close relatives are aquatic. we obtained genome sequences of two azospirillum species and analyzed their gene origins. while m ... | 2011 | 22216014 |
| intruders below the radar: molecular pathogenesis of bartonella spp. | summary: bartonella spp. are facultative intracellular pathogens that employ a unique stealth infection strategy comprising immune evasion and modulation, intimate interaction with nucleated cells, and intraerythrocytic persistence. infections with bartonella are ubiquitous among mammals, and many species can infect humans either as their natural host or incidentally as zoonotic pathogens. upon inoculation into a naive host, the bartonellae first colonize a primary niche that is widely accepted ... | 2012 | 22232371 |
| mercury-resistant rhizobial bacteria isolated from nodules of leguminous plants growing in high hg-contaminated soils. | a survey of symbiotic bacteria from legumes grown in high mercury-contaminated soils (almadén, spain) was performed to produce a collection of rhizobia which could be well adapted to the environmental conditions of this region and be used for restoration practices. nineteen hg-tolerant rhizobia were isolated from nodules of 11 legume species (of the genera medicago, trifolium, vicia, lupinus, phaseolus, and retama) and characterized. based on their growth on hg-supplemented media, the isolates w ... | 2012 | 22246528 |
| transformation of pwwo in rhizobium leguminosarum dpt to engineer toluene degrading ability for rhizoremediation. | rhizoremediation of organic xenobiotics is based on interactions between plants and their associated micro-organisms. the present work was designed to engineer a bacterial system having toluene degradation ability along with plant growth promoting characteristics for effective rhizoremediation. pwwo harboring the genes responsible for toluene breakdown was isolated from pseudomonas putida mtcc 979 and successfully transformed in rhizobium dpt. this resulted in a bacterial strain (dpt(t)) which h ... | 2011 | 23729882 |
| transformation of pwwo in rhizobium leguminosarum dpt to engineer toluene degrading ability for rhizoremediation. | rhizoremediation of organic xenobiotics is based on interactions between plants and their associated micro-organisms. the present work was designed to engineer a bacterial system having toluene degradation ability along with plant growth promoting characteristics for effective rhizoremediation. pwwo harboring the genes responsible for toluene breakdown was isolated from pseudomonas putida mtcc 979 and successfully transformed in rhizobium dpt. this resulted in a bacterial strain (dpt(t)) which h ... | 2011 | 23729882 |
| characterization of outer membrane vesicles from brucella melitensis and protection induced in mice. | the outer membrane vesicles (omvs) from smooth b. melitensis 16 m and a derived rough mutant, vtrm1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. proteomic analysis showed 29 proteins present in omvs from b. melitensis 16 m; some of them are well-known brucella immunogens such as sod, groes, omp31, omp25, omp19, bp26, and omp16. omvs from a rough vtrm1 induced significantly higher expression of il-12, tnfα, and ifnγ genes in bo ... | 2011 | 22242036 |
| characterization of outer membrane vesicles from brucella melitensis and protection induced in mice. | the outer membrane vesicles (omvs) from smooth b. melitensis 16 m and a derived rough mutant, vtrm1 strain, were purified and characterized with respect to protein content and induction of immune responses in mice. proteomic analysis showed 29 proteins present in omvs from b. melitensis 16 m; some of them are well-known brucella immunogens such as sod, groes, omp31, omp25, omp19, bp26, and omp16. omvs from a rough vtrm1 induced significantly higher expression of il-12, tnfα, and ifnγ genes in bo ... | 2011 | 22242036 |
| greenhouse studies of thiamethoxam effects on pea leaf weevil, sitona lineatus. | the pea leaf weevil, sitona lineatus l. (coleoptera: curculionidae), has recently emerged as an important pest of field peas in the canadian prairies. systemic seed-coated insecticides may provide a tool for the integrated pest management of this pest. therefore, several controlled assays were performed in order to determine effects of a recently registered neonicotinoid, (thiamethoxam) on s. lineatus damage to foliage, weevil mortality, fertility, egg viability, larval mortality, and root nodul ... | 2012 | 23461362 |
| evaluation of the effects of erythritol on gene expression in brucella abortus. | bacteria of the genus brucella have the unusual capability to catabolize erythritol and this property has been associated with their virulence mainly because of the presence of erythritol in bovine foetal tissues and because the attenuated s19 vaccine strain is the only brucella strain unable to oxydize erythritol. in this work we have analyzed the transcriptional changes produced in brucella by erythritol by means of two high throughput approaches: rna hybridization against a microarray contain ... | 2012 | 23272076 |
| genomic basis of broad host range and environmental adaptability of rhizobium tropici ciat 899 and rhizobium sp. prf 81 which are used in inoculants for common bean (phaseolus vulgaris l.). | rhizobium tropici ciat 899 and rhizobium sp. prf 81 are α-proteobacteria that establish nitrogen-fixing symbioses with a range of legume hosts. these strains are broadly used in commercial inoculants for application to common bean (phaseolus vulgaris) in south america and africa. both strains display intrinsic resistance to several abiotic stressful conditions such as low soil ph and high temperatures, which are common in tropical environments, and to several antimicrobials, including pesticides ... | 2012 | 23270491 |
| quorum sensing: a nobel target for antibacterial agents. | | 2012 | 23826557 |
| structural changes in medicago truncatula root nodules caused by short-term aluminum stress. | aluminum in the form of al(3+) is one of the most toxic heavy metal pollutants in nature and its effects are primarily root-related. roots of medicago truncatula exposed to 50 μm of alcl3 for 2 h and 24 h were examined by light and electron microscopy. changes in the appearance of the host cells, infection threads and bacteroidal tissue occurred during the first 2 h of al stress. microscopic observations showed that aluminum: (1) induced thickening of plant cell and infection threads (its) walls ... | 2012 | 23482822 |
| rhizobia species: a boon for "plant genetic engineering". | since past three decades new discoveries in plant genetic engineering have shown remarkable potentials for crop improvement. agrobacterium ti plasmid based dna transfer is no longer the only efficient way of introducing agronomically important genes into plants. recent studies have explored a novel plant genetic engineering tool, rhizobia sp., as an alternative to agrobacterium, thereby expanding the choice of bacterial species in agricultural plant biotechnology. rhizobia sp. serve as an open l ... | 2011 | 23024417 |
| autoantigen cross-reactive environmental antigen can trigger multiple sclerosis-like disease. | multiple sclerosis is generally considered an autoimmune disease resulting from interaction between predisposing genes and environmental factors, together allowing immunological self-tolerance to be compromised. the precise nature of the environmental inputs has been elusive, infectious agents having received considerable attention. a recent study generated an algorithm predicting naturally occurring t cell receptor (tcr) ligands from the proteome database. taking the example of a multiple scler ... | 2015 | 25962509 |
| a structure-based classification of class a β-lactamases, a broadly diverse family of enzymes. | for medical biologists, sequencing has become a commonplace technique to support diagnosis. rapid changes in this field have led to the generation of large amounts of data, which are not always correctly listed in databases. this is particularly true for data concerning class a β-lactamases, a group of key antibiotic resistance enzymes produced by bacteria. many genomes have been reported to contain putative β-lactamase genes, which can be compared with representative types. we analyzed several ... | 2016 | 26511485 |
| a structure-based classification of class a β-lactamases, a broadly diverse family of enzymes. | for medical biologists, sequencing has become a commonplace technique to support diagnosis. rapid changes in this field have led to the generation of large amounts of data, which are not always correctly listed in databases. this is particularly true for data concerning class a β-lactamases, a group of key antibiotic resistance enzymes produced by bacteria. many genomes have been reported to contain putative β-lactamase genes, which can be compared with representative types. we analyzed several ... | 2016 | 26511485 |
| annotation of protein domains reveals remarkable conservation in the functional make up of proteomes across superkingdoms. | the functional repertoire of a cell is largely embodied in its proteome, the collection of proteins encoded in the genome of an organism. the molecular functions of proteins are the direct consequence of their structure and structure can be inferred from sequence using hidden markov models of structural recognition. here we analyze the functional annotation of protein domain structures in almost a thousand sequenced genomes, exploring the functional and structural diversity of proteomes. we find ... | 2011 | 24710297 |
| sequence, structure and functional diversity of pd-(d/e)xk phosphodiesterase superfamily. | proteins belonging to pd-(d/e)xk phosphodiesterases constitute a functionally diverse superfamily with representatives involved in replication, restriction, dna repair and trna-intron splicing. their malfunction in humans triggers severe diseases, such as fanconi anemia and xeroderma pigmentosum. to date there have been several attempts to identify and classify new pd-(d/e)kk phosphodiesterases using remote homology detection methods. such efforts are complicated, because the superfamily exhibit ... | 2012 | 22638584 |
| keys to eukaryality: planctomycetes and ancestral evolution of cellular complexity. | planctomycetes are known to display compartmentalization via internal membranes, thus resembling eukaryotes. significantly, the planctomycete gemmata obscuriglobus has not only a nuclear region surrounded by a double-membrane, but is also capable of protein uptake via endocytosis. in order to clearly analyze implications for homology of their characters with eukaryotes, a correct understanding of planctomycete structure is an essential starting point. here we outline the major features of such s ... | 2012 | 22586422 |
| global and targeted lipid analysis of gemmata obscuriglobus reveals the presence of lipopolysaccharide, a signature of the classical gram-negative outer membrane. | planctomycete bacteria possess many unusual cellular properties, contributing to a cell plan long considered to be unique among the bacteria. however, data from recent studies are more consistent with a modified gram-negative cell plan. a key feature of the gram-negative plan is the presence of an outer membrane (om), for which lipopolysaccharide (lps) is a signature molecule. despite genomic evidence for an om in planctomycetes, no biochemical verification has been reported. we attempted to det ... | 2016 | 26483522 |