| crystal structure of activated chey1 from helicobacter pylori. | chemotaxis is an important virulence factor for helicobacter pylori colonization and infection. the chemotactic system of h. pylori is marked by the presence of multiple response regulators: chey1, one chey-like-containing chea protein (cheay2), and three chev proteins. recent studies have demonstrated that these molecules play unique roles in the chemotactic signal transduction mechanisms of h. pylori. here we report the crystal structures of bef(3(-)-activated chey1 from h. pylori resolved to ... | 2010 | 20207758 |
| [effect of lectins from azospirillum brasilense to peroxidase and oxalate oxidase activity regulation in wheat roots]. | lectins were extracted from the surface of nitrogen-fixing soil bacteria azospirillum brasilense sp7 and from its mutant a. brasilense sp7.2.3 defective in lectin activity. the ability oflectins to stimulate the rapid formation of hydrogen peroxide related to increase of oxalate oxidase and peroxidase activity in the roots of wheat seedlings has been demonstrated. the most rapid induced pathway of hydrogen peroxide formation in the roots of wheat seedlings was the oxalic acid oxidation by oxalat ... | 2010 | 20235434 |
| mutagenesis and functional characterization of the four domains of glnd, a bifunctional nitrogen sensor protein. | glnd is a bifunctional uridylyltransferase/uridylyl-removing enzyme (utase/ur) and is believed to be the primary sensor of nitrogen status in the cell by sensing the level of glutamine in enteric bacteria. it plays an important role in nitrogen assimilation and metabolism by reversibly regulating the modification of p(ii) protein; p(ii) in turn regulates a variety of other proteins. glnd appears to have four distinct domains: an n-terminal nucleotidyltransferase (nt) domain; a central hd domain, ... | 2010 | 20363937 |
| [plasmid rearrangements and azospirillum brasilense biofilm formation]. | | 2010 | 20411670 |
| a new p(ii) protein structure identifies the 2-oxoglutarate binding site. | p(ii) proteins of bacteria, archaea, and plants regulate many facets of nitrogen metabolism. they do so by interacting with their target proteins, which can be enzymes, transcription factors, or membrane proteins. a key feature of the ability of p(ii) proteins to sense cellular nitrogen status and to interact accordingly with their targets is their binding of the key metabolic intermediate 2-oxoglutarate (2-og). however, the binding site of this ligand within p(ii) proteins has been controversia ... | 2010 | 20493877 |
| metabolic flexibility revealed in the genome of the cyst-forming alpha-1 proteobacterium rhodospirillum centenum. | rhodospirillum centenum is a photosynthetic non-sulfur purple bacterium that favors growth in an anoxygenic, photosynthetic n2-fixing environment. it is emerging as a genetically amenable model organism for molecular genetic analysis of cyst formation, photosynthesis, phototaxis, and cellular development. here, we present an analysis of the genome of this bacterium. | 2010 | 20500872 |
| influence of forest trees on the distribution of mineral weathering-associated bacterial communities of the scleroderma citrinum mycorrhizosphere. | in acidic forest soils, availability of inorganic nutrients is a tree-growth-limiting factor. a hypothesis to explain sustainable forest development proposes that tree roots select soil microbes involved in central biogeochemical processes, such as mineral weathering, that may contribute to nutrient mobilization and tree nutrition. here we showed, by combining soil analyses with cultivation-dependent analyses of the culturable bacterial communities associated with the widespread mycorrhizal fung ... | 2010 | 20511429 |
| crystal structures of the apo and atp bound mycobacterium tuberculosis nitrogen regulatory pii protein. | pii constitutes a family of signal transduction proteins that act as nitrogen sensors in microorganisms and plants. mycobacterium tuberculosis (mtb) has a single homologue of pii whose precise role has as yet not been explored. we have solved the crystal structures of the mtb pii protein in its apo and atp bound forms to 1.4 and 2.4 a resolutions, respectively. the protein forms a trimeric assembly in the crystal lattice and folds similarly to the other pii family proteins. the mtb pii:atp binar ... | 2010 | 20521335 |
| [the structure of the o-specific polysaccharide from a mutant of nitrogen-fixing rhizobacterium azospirillum brasilense sp245 with an altered plasmid content]. | the rhizobacteria azospirillum brasilense sp245 produce antigenically different lipopolysaccharides lpsi and lpsii, both containing identical pentasaccharides built from d-rhamnose residues as the repeated chains of o-specific oligosaccharides (ops). in this study, we report the structure of the ops from a. brasilense lpsi(-)lpsii(-)-mutant sp245.5, which spontaneously lost the p85 and p120 plasmids upon the formation of a new 300-mda megaplasmid after the long-term storage of the bacteria in a ... | 2010 | 20531482 |
| global transcriptional profiling of burkholderia pseudomallei under salt stress reveals differential effects on the bsa type iii secretion system. | burkholderia pseudomallei is the causative agent of melioidosis where the highest reported incidence world wide is in the northeast of thailand, where saline soil and water are prevalent. moreover, recent reports indicate a potential pathogenic role for b. pseudomallei in cystic fibrosis lung disease, where an increased sodium chloride (nacl) concentration in airway surface liquid has been proposed. these observations raise the possibility that high salinity may represent a favorable niche for b ... | 2010 | 20540813 |
| gain-of-function mutations cluster in distinct regions associated with the signalling pathway in the pas domain of the aerotaxis receptor, aer. | the aer receptor monitors internal energy (redox) levels in escherichia coli with an fad-containing pas domain. here, we randomly mutagenized the region encoding residues 14-119 of the pas domain and found 72 aerotaxis-defective mutants, 24 of which were gain-of-function, signal-on mutants. the mutations were mapped onto an aer homology model based on the structure of the pas-fad domain in nifl from azotobacter vinlandii. signal-on lesions clustered in the fad binding pocket, the beta-scaffoldin ... | 2010 | 20545849 |
| two atypical l-cysteine-regulated nadph-dependent oxidoreductases involved in redox maintenance, l-cystine and iron reduction, and metronidazole activation in the enteric protozoan entamoeba histolytica. | we discovered novel catalytic activities of two atypical nadph-dependent oxidoreductases (ehno1/2) from the enteric protozoan parasite entamoeba histolytica. ehno1/2 were previously annotated as the small subunit of glutamate synthase (glutamine:2-oxoglutarate amidotransferase) based on similarity to authentic bacterial homologs. as e. histolytica lacks the large subunit of glutamate synthase, ehno1/2 were presumed to play an unknown role other than glutamine/glutamate conversion. transcriptomic ... | 2010 | 20592025 |
| gene encoding gamma-carbonic anhydrase is cotranscribed with argc and induced in response to stationary phase and high co2 in azospirillum brasilense sp7. | carbonic anhydrase (ca) is a ubiquitous enzyme catalyzing the reversible hydration of co2 to bicarbonate, a reaction underlying diverse biochemical and physiological processes. gamma class carbonic anhydrases (gamma-cas) are widespread in prokaryotes but their physiological roles remain elusive. at present, only gamma-ca of methanosarcina thermophila (cam) has been shown to have ca activity. genome analysis of a rhizobacterium azospirillum brasilense, revealed occurrence of orfs encoding one bet ... | 2010 | 20598158 |
| combined effects of co2 and light on the n2-fixing cyanobacterium trichodesmium ims101: a mechanistic view. | the marine diazotrophic cyanobacterium trichodesmium responds to elevated atmospheric co(2) partial pressure (pco(2)) with higher n(2) fixation and growth rates. to unveil the underlying mechanisms, we examined the combined influence of pco(2) (150 and 900 microatm) and light (50 and 200 micromol photons m(-2) s(-1)) on trichodesmium ims101. we expand on a complementary study that demonstrated that while elevated pco(2) enhanced n(2) fixation and growth, oxygen evolution and carbon fixation incr ... | 2010 | 20625002 |
| growth of quailbush in acidic, metalliferous desert mine tailings: effect of azospirillum brasilense sp6 on biomass production and rhizosphere community structure. | mine tailing deposits in semiarid and arid environments frequently remain devoid of vegetation due to the toxicity of the substrate and the absence of a diverse soil microbial community capable of supporting seed germination and plant growth. the contribution of the plant growth promoting bacterium (pgpb) azospirillum brasilense sp6 to the growth of quailbush in compost-amended, moderately acidic, high-metal content mine tailings using an irrigation-based reclamation strategy was examined along ... | 2010 | 20632001 |
| control of amtb-glnk complex formation by intracellular levels of atp, adp, and 2-oxoglutarate. | p(ii) proteins are one of the most widespread families of signal transduction proteins in nature, being ubiquitous throughout bacteria, archaea, and plants. they play a major role in coordinating nitrogen metabolism by interacting with, and regulating the activities of, a variety of enzymes, transcription factors, and membrane transport proteins. the regulatory properties of p(ii) proteins derive from their ability to bind three effectors: atp, adp, and 2-oxoglutarate. however, a clear model to ... | 2010 | 20639578 |
| elimination of rubisco alters the regulation of nitrogenase activity and increases hydrogen production in rhodospirillum rubrum. | nitrogenase not only reduces atmospheric nitrogen to ammonia, but also reduces protons to hydrogen (h(2)). the nitrogenase system is the primary means of h(2) production under photosynthetic and nitrogen-limiting conditions in many photosynthetic bacteria, including rhodospirillum rubrum. the efficiency of this biological h(2) production largely depends on the nitrogenase enzyme and the availability of atp and electrons in the cell. previous studies showed that blockage of the co(2) fixation pat ... | 2010 | 20652089 |
| structural basis for the regulation of ntca-dependent transcription by proteins pipx and pii. | pii, an ancient and widespread signaling protein, transduces nitrogen/carbon/energy abundance signals through interactions with target proteins. we clarify structurally how pii regulates gene expression mediated by the transcription factor ntca, the global nitrogen regulator of cyanobacteria, shedding light on ntca structure and function and on how ntca is activated by 2-oxoglutarate (2og) and coactivated by the nonenzymatic pii target, protein pipx. we determine for the cyanobacteria synechococ ... | 2010 | 20716687 |
| [localization of denitrification genes in plasmid dna of bacteria azospirillum brasilense]. | in 85-mda plasmid (p85) of plant-associated bacteria azospirillum brasilense sp245 model strain, the genes encoding copper-containing nitrite reductase (nirk); heterodimeric no-reductase (norcb); norq and nord proteins affecting synthesis and (or) activation of nirk and (or) no-reductase (norqd); catalytic subunit i ofcytochrom c oxidase (cccon); presumable no sensor carrying two hemeerythrine domains (orf181); and an enzyme required for synthesis of presumable no antagonist, homocystein (metc) ... | 2010 | 20795494 |
| quantification of nitrogen reductase and nitrite reductase genes in soil of thinned and clear-cut douglas-fir stands by using real-time pcr. | the abundance of nifh, nirs, and nirk gene fragments involved in nitrogen (n) fixation and denitrification in thinned second-growth douglas-fir (pseudotsuga menziesii subsp. menziesii [mirb.] franco) forest soil was investigated by using quantitative real-time pcr. prokaryotic n cycling is an important aspect of n availability in forest soil. the abundance of universal nifh, azotobacter sp.-specific nifh (nifh-g1), nirs, and nirk gene fragments in unthinned control and 30, 90, and 100% thinning ... | 2010 | 20802070 |
| genomic encyclopedia of sugar utilization pathways in the shewanella genus. | carbohydrates are a primary source of carbon and energy for many bacteria. accurate projection of known carbohydrate catabolic pathways across diverse bacteria with complete genomes constitutes a substantial challenge due to frequent variations in components of these pathways. to address a practically and fundamentally important challenge of reconstruction of carbohydrate utilization machinery in any microorganism directly from its genomic sequence, we combined a subsystems-based comparative gen ... | 2010 | 20836887 |
| the auxin-signaling pathway is required for the lateral root response of arabidopsis to the rhizobacterium phyllobacterium brassicacearum. | plant root development is highly responsive both to changes in nitrate availability and beneficial microorganisms in the rhizosphere. we previously showed that phyllobacterium brassicacearum stm196, a plant growth-promoting rhizobacteria strain isolated from rapeseed roots, alleviates the inhibition exerted by high nitrate supply on lateral root growth. since soil-borne bacteria can produce iaa and since this plant hormone may be implicated in the high nitrate-dependent control of lateral root d ... | 2010 | 20844890 |
| the genetic diversity of culturable nitrogen-fixing bacteria in the rhizosphere of wheat. | a total of 17 culturable nitrogen-fixing bacterial strains associated with the roots of wheat growing in different regions of greece were isolated and characterized for plant-growth-promoting traits such as auxin production and phosphate solubilization. the phylogenetic position of the isolates was first assessed by the analysis of the pcr-amplified 16s rrna gene. the comparative sequence analysis and phylogenetic analysis based on 16s rrna gene sequences show that the isolates recovered in this ... | 2011 | 20857096 |
| a hybrid two-component system protein from azospirillum brasilense sp7 was involved in chemotaxis. | we here report the sequence and functional analysis of org35 of azospirillum brasilense sp7, which was originally identified to be able to interact with nifa in yeast-two-hybrid system. the org35 encodes a hybrid two-component system protein, including n-terminal pas domains, a histidine kinase (hpk) domain and a response regulator (rr) domain in c-terminal. to determine the function of the org35, a deletion-insertion mutant in pas domain [named sp7353] and a complemental strain sp7353c were con ... | 2010 | 20869221 |
| efficacy of trypsin in enhancing assessment of bacterial colonisation of vascular catheters. | since the number of organisms isolated from a medical device is crucial in assessing the likelihood of device-associated infection, we examined whether incubation of catheters in trypsin before sonication can increase the yield of superficially colonised vascular catheters in vitro and those removed from patients. polyurethane and silicone catheters were individually colonised in vitro with individual clinical isolates including staphylococcus aureus and escherichia coli. equal numbers of 1 cm s ... | 2010 | 20880606 |
| modeling of pyruvate decarboxylases from ethanol producing bacteria. | pyruvate decarboxylase (pdc) is a key enzyme in homoethanol fermentation process, which decarboxylates 2-keto acid pyruvate into acetaldehyde and carbon dioxide. pdc enzymes from potential ethanol-producing bacteria such as zymomonas mobilis, zymobacter palmae and sarcina ventriculi have different k(m) and k(cat) values for the substrate pyruvate at their respective optimum ph. in this study, the putative three-dimensional structures of pdc dimer of z. palmae pdc and s. ventriculi pdc were gener ... | 2010 | 20975902 |
| mechanism of 2-oxoglutarate signaling by the synechococcus elongatus pii signal transduction protein. | p(ii) proteins control key processes of nitrogen metabolism in bacteria, archaea, and plants in response to the central metabolites atp, adp, and 2-oxoglutarate (2-og), signaling cellular energy and carbon and nitrogen abundance. this metabolic information is integrated by p(ii) and transmitted to regulatory targets (key enzymes, transporters, and transcription factors), modulating their activity. in oxygenic phototrophs, the controlling enzyme of arginine synthesis, n-acetyl-glutamate kinase (n ... | 2010 | 21041661 |
| the pseudomonas secondary metabolite 2,4-diacetylphloroglucinol is a signal inducing rhizoplane expression of azospirillum genes involved in plant-growth promotion. | during evolution, plants have become associated with guilds of plant-growth-promoting rhizobacteria (pgpr), which raises the possibility that individual pgpr populations may have developed mechanisms to cointeract with one another on plant roots. we hypothesize that this has resulted in signaling phenomena between different types of pgpr colonizing the same roots. here, the objective was to determine whether the pseudomonas secondary metabolite 2,4-diacetylphloroglucinol (dapg) can act as a sign ... | 2011 | 21043573 |
| characterization of cell surface and extracellular matrix remodeling of azospirillum brasilense chemotaxis-like 1 signal transduction pathway mutants by atomic force microscopy. | to compete in complex microbial communities, bacteria must sense environmental changes and adjust cellular functions for optimal growth. chemotaxis-like signal transduction pathways are implicated in the regulation of multiple behaviors in response to changes in the environment, including motility patterns, exopolysaccharide production, and cell-to-cell interactions. in azospirillum brasilense, cell surface properties, including exopolysaccharide production, are thought to play a direct role in ... | 2010 | 21105907 |
| nitrogen fixation and hydrogen metabolism in cyanobacteria. | this review summarizes recent aspects of (di)nitrogen fixation and (di)hydrogen metabolism, with emphasis on cyanobacteria. these organisms possess several types of the enzyme complexes catalyzing n(2) fixation and/or h(2) formation or oxidation, namely, two mo nitrogenases, a v nitrogenase, and two hydrogenases. the two cyanobacterial ni hydrogenases are differentiated as either uptake or bidirectional hydrogenases. the different forms of both the nitrogenases and hydrogenases are encoded by di ... | 2010 | 21119016 |
| dynamics, diversity and function of endophytic siderophore-producing bacteria in rice. | siderophore production confers to bacteria competitive advantages to colonize plant tissues and to exclude other microorganisms from the same ecological niche. this work shows that the community of endophytic siderophore-producing bacteria (spb) associated to oryza sativa cultivated in uruguayan soils is dynamic and diverse. these bacteria were present in grains, roots, and leaves, and their density fluctuated between log(10) 3.44 and log(10) 5.52 cfu g(-1) fresh weight (fw) during the plant gro ... | 2010 | 21128071 |
| a minimal model of metabolism-based chemotaxis. | since the pioneering work by julius adler in the 1960's, bacterial chemotaxis has been predominantly studied as metabolism-independent. all available simulation models of bacterial chemotaxis endorse this assumption. recent studies have shown, however, that many metabolism-dependent chemotactic patterns occur in bacteria. we hereby present the simplest artificial protocell model capable of performing metabolism-based chemotaxis. the model serves as a proof of concept to show how even the simples ... | 2010 | 21170312 |
| cyclic gmp controls rhodospirillum centenum cyst development. | adenylyl cyclases are widely distributed across all kingdoms whereas guanylyl cyclases are generally thought to be restricted to eukaryotes. here we report that the α-proteobacterium rhodospirillum centenum secretes cgmp when developing cysts and that a guanylyl cyclase deletion strain fails to synthesize cgmp and is defective in cyst formation. the r. centenum cyclase was purified and shown to effectively synthesize cgmp from gtp in vitro, demonstrating that it is a functional guanylyl cyclase. ... | 2011 | 21214648 |
| role of pii proteins in nitrogen fixation control of herbaspirillum seropedicae strain smr1. | the pii protein family comprises homotrimeric proteins which act as transducers of the cellular nitrogen and carbon status in prokaryotes and plants. in herbaspirillum seropedicae, two pii-like proteins (glnb and glnk), encoded by the genes glnb and glnk, were identified. the glnb gene is monocistronic and its expression is constitutive, while glnk is located in the nlmaglnkamtb operon and is expressed under nitrogen-limiting conditions. | 2011 | 21223584 |
| nifb and nifen protein levels are regulated by clpx2 under nitrogen fixation conditions in azotobacter vinelandii. | the major part of biological nitrogen fixation is catalysed by the molybdenum nitrogenase that carries at its active site the iron and molybdenum cofactor (femo-co). the nitrogen fixation (nif) genes required for the biosynthesis of femo-co are derepressed in the absence of a source of fixed nitrogen. the nifb gene product is remarkable because it assembles nifb-co, a complex cluster proposed to comprise a [6fe-9s-x] cluster, from simpler [fe-s] clusters common to other metabolic pathways. nifb- ... | 2011 | 21231969 |
| a cher/cheb fusion protein is involved in cyst cell development and chemotaxis in azospirillum brasilense sp7. | we here report the sequence and functional analysis of cstb of azospirillum brasilense sp7. the predicted cstb contains c-terminal two pas domains and n-terminal part which has similarity with cheb-cher fusion protein. cstb mutants had reduced swarming ability compared to that of a. brasilense wild-type strain, implying that cstb was involved in chemotaxis in a. brasilense. a microscopic analysis revealed that cstb mutants developed mature cyst cells more quickly than wild type, indicating that ... | 2011 | 21232929 |
| an extracytoplasmic function sigma factor cotranscribed with its cognate anti-sigma factor confers tolerance to nacl, ethanol and methylene blue in azospirillum brasilense sp7. | azospirillum brasilense, a plant-growth-promoting rhizobacterium, is exposed to changes in its abiotic environment, including fluctuations in temperature, salinity, osmolarity, oxygen concentration and nutrient concentration, in the rhizosphere and in the soil. since extra-cytoplasmic function (ecf) sigma factors play an important role in stress adaptation, we analysed the role of ecf sigma factor (also known as rpoe or s(e)) in abiotic stress tolerance in a. brasilense. an in-frame rpoe deletio ... | 2011 | 21233159 |
| azospirillum brasilense siderophores with antifungal activity against colletotrichum acutatum. | anthracnose, caused by the fungus colletotrichum acutatum is one of the most important diseases in strawberry crop. due to environmental pollution and resistance produced by chemical fungicides, nowadays biological control is considered a good alternative for crop protection. among biocontrol agents, there are plant growth-promoting bacteria, such as members of the genus azospirillum. in this work, we demonstrate that under iron limiting conditions different strains of a. brasilense produce side ... | 2011 | 21234749 |
| cdna-aflp analysis of differential gene expression related to cell chemotactic and encystment of azospirillum brasilense. | our previous study indicated org35 was involved in chemotaxis and interacted with nitrogen fixation transcriptional activator nifa via pas domain. in order to reveal the role of org35 in nitrogen regulation, the downstream target genes of org35 were identified. we here report differentially expressed genes in org35 mutants comparing with wild type sp7 by means of cdna-aflp. four up-regulated transcript-derived fragments (tdfs) homologues of chemotaxis transduction proteins were found, including ... | 2011 | 21242066 |
| camp, c-di-gmp, c-di-amp and now cgmp: bacteria use them all! | | 2011 | 21255104 |
| the colr/cols two-component system plays multiple roles in the pathogenicity of the citrus canker pathogen xanthomonas citri subsp. citri. | bacterial citrus canker disease, which is caused by xanthomonas citri subsp. citri, is one of the most devastating diseases of citrus plants. in this study, we characterized the role of the two-component regulatory system colr/cols in the pathogenicity of x. citri subsp. citri. cols mutants (256a10 and 421e7), colr mutants (386c6 and 417e10), and a colr cols double mutant (306dsr) all lost pathogenicity and produced no symptoms on grapefruit leaves inoculated by either pressure infiltration or t ... | 2011 | 21257774 |
| naringenin regulates expression of genes involved in cell wall synthesis in herbaspirillum seropedicae. | five thousand mutants of herbaspirillum seropedicae smr1 carrying random insertions of transposon ptnmod-ogmkmlacz were screened for differential expression of lacz in the presence of naringenin. among the 16 mutants whose expression was regulated by naringenin were genes predicted to be involved in the synthesis of exopolysaccharides, lipopolysaccharides, and auxin. these loci are probably involved in establishing interactions with host plants. | 2011 | 21257805 |
| the role of the antimicrobial compound 2,4-diacetylphloroglucinol in the impact of biocontrol pseudomonas fluorescens f113 on azospirillum brasilense phytostimulators. | pseudomonads producing the antimicrobial metabolite 2,4-diacetylphloroglucinol (phl) can control soil-borne phytopathogens, but their impact on other plant-beneficial bacteria remains poorly documented. here, the effects of synthetic phl and phl(+) pseudomonas fluorescens f113 on azospirillum brasilense phytostimulators were investigated. most a. brasilense strains were moderately sensitive to phl. in vitro, phl induced accumulation of carotenoids and poly-ß-hydroxybutyrate-like granules, cytopl ... | 2011 | 21273247 |
| structure of glnk1, a signalling protein from archaeoglobus fulgidus. | glnb and glnk are ancient signalling proteins that play a crucial role in the regulation of nitrogen assimilation. both protein types can be present in the same genome as either single or multiple copies. however, the gene product of glnk is always found in an operon together with an amt gene encoding an ammonium-transport (amt) protein. complex formation between glnk and amt blocks ammonium uptake and depends on the nitrogen level in the cell, which is regulated through the binding of specific ... | 2011 | 21301082 |
| structural and functional peculiarities of the lipopolysaccharide of azospirillum brasilense sr55, isolated from the roots of triticum durum. | azospirillum brasilense sr55, isolated from the rhizosphere of triticum durum, was classified as serogroup ii on the basis of serological tests. such serogroup affiliation is uncharacteristic of wheat-associated azospirillum species. the lipid a of a. brasilense sr55 lipopolysaccharide contained 3-hydroxytetradecanoic, 3-hydroxyhexadecanoic, hexadecanoic and octadecenoic fatty acids. the structure of the lipopolysaccharide's o polysaccharide was established, with the branched octasaccharide repe ... | 2011 | 21334868 |
| characterization of lateral flagella of selenomonas ruminantium. | selenomonas ruminantium produces a tuft of flagella near the midpoint of the cell body and swims by rotating the cell body along the cell's long axis. the flagellum is composed of a single kind of flagellin, which is heavily glycosylated. the hook length of s. ruminantium is almost double that of salmonella. | 2011 | 21335384 |
| transcriptome analysis of the rhizosphere bacterium azospirillum brasilense reveals an extensive auxin response. | the rhizosphere bacterium azospirillum brasilense produces the auxin indole-3-acetic acid (iaa) through the indole-3-pyruvate pathway. as we previously demonstrated that transcription of the indole-3-pyruvate decarboxylase (ipdc) gene is positively regulated by iaa, produced by a. brasilense itself or added exogenously, we performed a microarray analysis to study the overall effects of iaa on the transcriptome of a. brasilense. the transcriptomes of a. brasilense wild-type and the ipdc knockout ... | 2011 | 21340736 |
| response to saline stress and aquaporin expression in azospirillum-inoculated barley seedlings. | the ability of two strains of azospirillum brasilense to mitigate nacl stress in barley plants was evaluated. barley seedlings were inoculated and subjected to 200 mm nacl for 18 days. several days after nacl treatment, a significant decline in biomass as well as in height was observed in uninoculated plants. however, smaller reductions in biomass and height were detected in plants inoculated with strain az39. all the stressed plants showed significantly higher na(+) but lower k(+) contents in t ... | 2011 | 21365472 |
| azospirillum and arbuscular mycorrhizal colonization enhance rice growth and physiological traits under well-watered and drought conditions. | the response of rice plants to inoculation with an arbuscular mycorrhizal (am) fungus, azospirillum brasilense, or combination of both microorganisms, was assayed under well-watered or drought stress conditions. water deficit treatment was imposed by reducing the amount of water added, but am plants, with a significantly higher biomass, received the same amount of water as non-am plants, with a poor biomass. thus, the water stress treatment was more severe for am plants than for non-am plants. t ... | 2011 | 21377754 |
| indole-3-acetic acid biosynthesis in the biocontrol strain pseudomonas fluorescens psd and plant growth regulation by hormone overexpression. | pseudomonas fluorescens is an important biological component of agricultural soils that bestows a number of direct and indirect beneficial attributes to the plants. we analyzed the biocontrol strain p. fluorescens psd for indole-3-acetic acid (iaa) biosynthesis and studied the effect of its consequent manipulation on its plant-growth-promoting (pgp) potential. while the indole pyruvic acid (ipya) pathway commonly associated with pgp bacteria was lacking, the indole acetamide (iam) pathway genera ... | 2011 | 21397014 |
| characterization of a thiamin diphosphate-dependent phenylpyruvate decarboxylase from saccharomyces cerevisiae. | the product of the aro10 gene from saccharomyces cerevisiae was initially identified as a thiamine diphosphate-dependent phenylpyruvate decarboxylase with a broad substrate specificity. it was suggested that the enzyme could be responsible for the catabolism of aromatic and branched-chain amino acids, as well as methionine. in the present study, we report the overexpression of the aro10 gene product in escherichia coli and the first detailed in vitro characterization of this enzyme. the enzyme i ... | 2011 | 21501384 |
| tools for genetic manipulation of the plant growth-promoting bacterium azospirillum amazonense. | abstract: background: azospirillum amazonense has potential to be used as agricultural inoculant since it promotes plant growth without causing pollution, unlike industrial fertilizers. owing to these facts, the study of this species has gained interest. however, a detailed understanding of its genetics and physiology is limited by the absence of appropriate genetic tools for the study of this species. results: conjugation and electrotransformation methods were established utilizing vectors with ... | 2011 | 21575234 |
| genome of herbaspirillum seropedicae strain smr1, a specialized diazotrophic endophyte of tropical grasses. | the molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. the genome of h. seropedicae strain smr1 was sequenced and annotated by the paraná state genome programme-genopar. the genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. t ... | 2011 | 21589895 |
| soil factors exhibit greater influence than bacterial inoculation on alfalfa growth and nitrogen fixation. | in order to study effects of soil factors and bacterial inoculation on alfalfa (medicago sativa), plants were inoculated with ensifer meliloti l33 and azospirillum brasilense sp7 in pot experiments using two different soils separately as well as in a mixture. one soil was contaminated with chemical waste products; the other was an arable soil. soil factors, including availability of macro- and micronutrients as well as carbon and nitrogen contents were found to exhibit a much greater influence o ... | 2011 | 21627671 |
| in vitro interaction between the ammonium transport protein amtb and partially uridylylated forms of the p(ii) protein glnz. | the ammonium transport family amt/rh comprises ubiquitous integral membrane proteins that facilitate ammonium movement across biological membranes. besides their role in transport, amt proteins also play a role in sensing the levels of ammonium in the environment, a process that depends on complex formation with cytosolic proteins of the p(ii) family. trimeric p(ii) proteins from a variety of organisms undergo a cycle of reversible posttranslational modification according to the prevailing nitro ... | 2011 | 21645649 |
| surface colonization by azospirillum brasilense sm in the indole-3-acetic acid dependent growth improvement of sorghum. | the key to improving plant productivity is successful bacterial-plant interaction in the rhizosphere that can be maintained in the environment. the results presented here confirm azospirillum brasilense strain sm as a competent plant growth promoting bacterium over mid- and long-term associations with sorghum. this study establishes that plant growth can be directly correlated with the associated bacterium's indole-3-acetic acid (iaa) production capability as iaa over-expressing variants, smp30 ... | 2011 | 21656820 |
| genomic insights into the versatility of the plant growth-promoting bacterium azospirillum amazonense. | abstract: | 2011 | 21838888 |
| volatile organic compounds from rhizobacteria increase biosynthesis of essential oils and growth parameters in peppermint (mentha piperita). | volatile organic compounds (vocs), characterized by low molecular weight and high vapor pressure, are produced by all organisms as part of normal metabolism, and play important roles in communication within and between organisms. we examined the effects of vocs released by three species of plant growth-promoting rhizobacteria (pseudomonas fluorescens, bacillus subtilis, azospirillum brasilense) on growth parameters and composition of essential oils (eo) in the aromatic plant mentha piperita (pep ... | 2011 | 21843946 |
| biodiversity of active and inactive bacteria in the gut of wood-feeding huhu beetle larvae (prionoplus reticularis). | huhu grubs (prionoplus reticularis) are wood-feeding beetle larvae endemic to new zealand and belonging to the family cerambycidae. compared to the wood-feeding lower termites very little is known about the diversity and activity of microorganisms associated with xylophagous cerambycid larvae. to address this we used pyrosequencing to evaluate the diversity of metabolically active and inactive bacteria in the huhu larvae gut. our estimate, that the gut harbours at least 1,800 phylotypes, is base ... | 2011 | 21841025 |
| 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 |
| identification and isolation of active n(2)o reducers in rice paddy soil. | dissolved n(2)o is occasionally detected in surface and ground water in rice paddy fields, whereas little or no n(2)o is emitted to the atmosphere above these fields. this indicates the occurrence of n(2)o reduction in rice paddy fields; however, identity of the n(2)o reducers is largely unknown. in this study, we employed both culture-dependent and culture-independent approaches to identify n(2)o reducers in rice paddy soil. in a soil microcosm, n(2)o and succinate were added as the electron ac ... | 2011 | 21677691 |
| changes in the bacterial community structure and diversity during bamboo retting. | microbial retting is a critical step in obtaining fiber bundles from bamboo culm using indigenous microorganisms. a cultivation-independent technique for monitoring the changes in bacteria community during bamboo retting was applied in this work. this technique involves genetic profiling of pcr-amplified small-subunit rrna and the single-strand conformation polymorphism (sscp) gel analysis of the pcr-amplified 16s rdna fragments. the study revealed that both the structure and the diversity of in ... | 2011 | 21695788 |
| Azospirillum formosense sp. nov., a novel diazotrophic bacterium isolated from agricultural soil. | A Gram-negative, spiral or rod-shaped, non-spore-forming diazotrophic bacterium (strain CC-Nfb-7T), was isolated from agricultural soil located in Yunlin County, Taiwan. The 16S rRNA gene sequence analysis of strain CC-Nfb-7T showed highest sequence similarity to Azospirillum brasilense DSM 1690T (97.4%), Azospirillum rugosum DSM 19657T (96.8%), and Azospirillum oryzae JCM 21588T (96.6%) and lower sequence similarity (< 96.5%) to all other Azospirillum species. DNA-DNA hybridizations of strain C ... | 2011 | 21742820 |
| heat stability of proteobacterial pii protein facilitate purification using a single chromatography step. | the p(ii) proteins comprise a family of widely distributed signal transduction proteins that integrate the signals of cellular nitrogen, carbon and energy status, and then regulate, by protein-protein interaction, the activity of a variety of target proteins including enzymes, transcriptional regulators and membrane transporters. we have previously shown that the p(ii) proteins from azospirillum brasilense, glnb and glnz, do not alter their migration behavior under native gel electrophoresis fol ... | 2011 | 21963770 |
| effect of genomic rearrangement on heavy metal tolerance in the plant-growth-promoting rhizobacterium azospirillum brasilense sp245. | a derivative of azospirillum brasilense sp245, sp245.5, which spontaneously lost 85 and 120 mda replicons upon the formation of a new megaplasmid, has been shown to produce a novel lipopolysaccharide and to lose calcofluor-binding polysaccharides. as compared to sp245, the derivative displays notably increased heavy metal tolerance. the phenotypes of sp245 and sp245.5 are characterized by the following minimal inhibitory concentrations (mics) of heavy metals: 0.5 and 0.9 μmol l(-1) of ag(+), 0.4 ... | 2011 | 22130692 |
| crystal structure of the glnz-drag complex reveals a different form of pii-target interaction. | nitrogen metabolism in bacteria and archaea is regulated by a ubiquitous class of proteins belonging to the p(ii)family. p(ii) proteins act as sensors of cellular nitrogen, carbon, and energy levels, and they control the activities of a wide range of target proteins by protein-protein interaction. the sensing mechanism relies on conformational changes induced by the binding of small molecules to p(ii) and also by p(ii) posttranslational modifications. in the diazotrophic bacterium azospirillum b ... | 2011 | 22074780 |
| An improved rapid method for the preparation of d-rhamnose. | A method is developed for the preparation of d-rhamnose from an O-polysaccharide (OPS) isolated by mild acid hydrolysis of Azospirillum brasilense SR75 cell mass. After the OPS hydrolysis, d-rhamnose was recovered by gel-permeation chromatography on Toyopearl TSK HW-40 and was crystallized. The sugar activity was demonstrated immunochemically. The advantages of the method are that it expedites and simplifies the extraction of d-rhamnose and increases its yield. | 2011 | 22099380 |
| characterization of nitrogen-fixing bacteria isolated from field-grown barley, oat, and wheat. | diazotrophic bacteria were isolated from the rhizosphere of field-grown triticum aestivum, hordeum vulgare, and avena sativa grown in various regions of greece. one isolate, with the highest nitrogen-fixation ability from each of the eleven rhizospheres, was selected for further characterisation. diazotrophic strains were assessed for plant-growth-promoting traits such as indoleacetic acid production and phosphate solubilisation. the phylogenies of 16s rrna gene of the selected isolates were com ... | 2011 | 21887633 |
| Microbial diversity of biofilm communities in microniches associated with the didemnid ascidian Lissoclinum patella. | We assessed the microbial diversity and microenvironmental niche characteristics in the didemnid ascidian Lissoclinum patella using 16S rRNA gene sequencing, microsensor and imaging techniques. L. patella harbors three distinct microbial communities spatially separated by few millimeters of tunic tissue: (i) a biofilm on its upper surface exposed to high irradiance and O(2) levels, (ii) a cloacal cavity dominated by the prochlorophyte Prochloron spp. characterized by strong depletion of visible ... | 2011 | 22134643 |
| Microbial diversity of biofilm communities in microniches associated with the didemnid ascidian Lissoclinum patella. | We assessed the microbial diversity and microenvironmental niche characteristics in the didemnid ascidian Lissoclinum patella using 16S rRNA gene sequencing, microsensor and imaging techniques. L. patella harbors three distinct microbial communities spatially separated by few millimeters of tunic tissue: (i) a biofilm on its upper surface exposed to high irradiance and O(2) levels, (ii) a cloacal cavity dominated by the prochlorophyte Prochloron spp. characterized by strong depletion of visible ... | 2011 | 22134643 |
| Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense. | Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utili ... | 2012 | 22092983 |
| the chemotaxis-like che1 pathway has an indirect role in adhesive cell properties of azospirillum brasilense. | the azospirillum brasilense chemotaxis-like che1 signal transduction pathway was recently shown to modulate changes in adhesive cell surface properties that, in turn, affect cell-to-cell aggregation and flocculation behaviors rather than flagellar-mediated chemotaxis. attachment to surfaces and root colonization may be functions related to flocculation. here, the conditions under which a. brasilense wild-type sp7 and che1 mutant strains attach to abiotic and biotic surfaces were examined using i ... | 2011 | 22092709 |
| identification and characterization of phbf: a dna binding protein with regulatory role in the phb metabolism of herbaspirillum seropedicae smr1. | herbaspirillum seropedicae smr1 is a nitrogen fixing endophyte associated with important agricultural crops. it produces polyhydroxybutyrate (phb) which is stored intracellularly as granules. however, phb metabolism and regulatory control is not yet well studied in this organism. | 2011 | 21999748 |
| characterization of the mmsab-arad1 (gguabc) genes of agrobacterium tumefaciens. | the chve-gguabc operon plays a critical role in both virulence and sugar utilization through the activities of the periplasmic chve protein, which binds to a variety of sugars. the roles of the ggua, ggub, and gguc are not known. while ggua and ggub are homologous to bacterial abc transporters, earlier genetic analysis indicated that they were not necessary for utilization of sugars as the sole carbon source. to further examine this issue, in-frame deletions were constructed separately for each ... | 2011 | 21984786 |
| Alginate beads provide a beneficial physical barrier against native microorganisms in wastewater treated with immobilized bacteria and microalgae. | When the freshwater microalga Chlorella sorokiniana and the plant growth-promoting bacterium Azospirillum brasilense were deployed as free suspensions in unsterile, municipal wastewater for tertiary wastewater treatment, their population was significantly lower compared with their populations in sterile wastewater. At the same time, the numbers of natural microfauna and wastewater bacteria increased. Immobilization of C. sorokiniana and A. brasilense in small (2-4 mm in diameter), polymer Ca-alg ... | 2011 | 22038243 |
| How post-translational modification of nitrogenase is circumvented in Rhodopseudomonas palustris strains that produce hydrogen gas constitutively. | Nitrogenase catalyzes the conversion of dinitrogen gas (N(2)) and protons to ammonia and hydrogen gas (H(2)). This is a catalytically difficult reaction that requires large amounts of ATP and reducing power. Thus nitrogenase is not normally expressed or active in bacteria grown with a readily utilized nitrogen source like ammonium. nifA* mutants of the purple nonsulfur phototrophic bacterium Rhodopseudomonas palustris have been described that express nitrogenase genes constitutively and produce ... | 2011 | 22179236 |
| Mechanism of disruption of the Amt-GlnK complex by P(II)-mediated sensing of 2-oxoglutarate. | GlnK proteins regulate the active uptake of ammonium by Amt transport proteins by inserting their regulatory T-loops into the transport channels of the Amt trimer and physically blocking substrate passage. They sense the cellular nitrogen status through 2-oxoglutarate, and the energy level of the cell by binding both ATP and ADP with different affinities. The hyperthermophilic euryarchaeon Archaeoglobus fulgidus possesses three Amt proteins, each encoded in an operon with a GlnK ortholog. One of ... | 2011 | 22039461 |
| 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 |
| Production of indole-3-acetic acid via the indole-3-acetamide pathway in the plant-beneficial bacterium, Pseudomonas chlororaphis O6, is inhibited by ZnO nanoparticles but enhanced by CuO nanoparticles. | The beneficial bacterium Pseudomonas chlororaphis O6 (PcO6) produces indole-3-acetic acid (IAA), a plant growth regulator. However, the pathway involved in IAA production in this bacterium has not been reported. In this paper we describe the involvement of the indole-3-acetamide (IAM) pathway in IAA production in PcO6 and the effects of CuO and ZnO nanoparticles (NPs). Sublethal levels of CuO and ZnO NPs differentially affected the levels of IAA secreted in medium containing tryptophan as the pr ... | 2011 | 22210218 |
| environmental factors affecting the expression of pilab as well as the proteome and transcriptome of the grass endophyte azoarcus sp. strain bh72. | bacterial communication is involved in regulation of cellular mechanisms such as metabolic processes, microbe-host interactions or biofilm formation. in the nitrogen-fixing model endophyte of grasses azoarcus sp. strain bh72, known cell-cell signaling systems have not been identified; however, the pila gene encoding the structural protein of type iv pili that are essential for plant colonization appears to be regulated in a population density-dependent manner. | 2012 | 22276194 |
| 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 |
| absorption efficiency of n, p, k through triple inoculation of wheat (triticum aestivum l.) by azospirillum brasilense, streptomyces sp., glomus intraradices and manure application. | this study examined the effects of different biofertilizers and manure on the absorption and absorption efficiency of macronutrients by wheat in alborz province, iran. the experimental design was factorial in the form of a randomized complete block design with three replications. the four factors of the experiment were azospirillum (with 600 g/ha and without), mycorrhiza (with 1 kg/ha and without), streptomyces (with 0.5 kg/ha and without) and manure (with 30 t/ha and without). to measure n, p a ... | 2011 | 23573008 |
| production of indole acetic acid by pseudomonas sp.: effect of coinoculation with mesorhizobium sp. cicer on nodulation and plant growth of chickpea (cicer arietinum). | pseudomonas isolates obtained from the rhizosphere of chickpea (cicer arietinum l.) and green gram (vigna radiata) were found to produce significant amount of indole acetic acid (iaa) when grown in a lb medium broth supplemented with l-tryptophan. seed bacterization of chickpea cultivar c235 with different pseudomonas isolates showed stunting effect on the development of root and shoot at 5 and 10 days of seedling growth except the strains mps79 and mps90 that showed stimulation of root growth, ... | 2011 | 23572992 |
| effect of arbuscular mycorrhizal inoculations on seedling growth and biomass productivity of two bamboo species. | a study was conducted to identify suitable arbuscular mycorrhizal (am) fungi for inoculation of bambusa bambos and dendrocalamus strictus at nursery stage for increasing growth and productivity. twelve am species, isolated from bamboo and other common trees of bundelkhand were used for inoculations. in b. bambos, total dry weight and phosphorus (p) uptake were significantly increased by all studied fungi and shoot length was increased by eight am inoculants. maximum mycorrhizal dependency (md) w ... | 2011 | 23729895 |
| effect of arbuscular mycorrhizal inoculations on seedling growth and biomass productivity of two bamboo species. | a study was conducted to identify suitable arbuscular mycorrhizal (am) fungi for inoculation of bambusa bambos and dendrocalamus strictus at nursery stage for increasing growth and productivity. twelve am species, isolated from bamboo and other common trees of bundelkhand were used for inoculations. in b. bambos, total dry weight and phosphorus (p) uptake were significantly increased by all studied fungi and shoot length was increased by eight am inoculants. maximum mycorrhizal dependency (md) w ... | 2011 | 23729895 |
| interaction of azospirillum brasilense and glomus intrarradix in sugar cane roots. | fifteen-day-old variety na 56-79 sugar cane seedlings were inoculated with azospirillum brasilense and glomus intrarradix. this article aims at examining changes in sugar cane root seedlings inoculated with glomus intrarradix and azospirillum brasilense, the increase in microbial biomass and the acetylene reduction process as well. the internal root colonization was studied 20 days after inoculation using scanning and a transmission electron microscope. both microorganisms entered the sugar cane ... | 2011 | 23449160 |
| interaction of azospirillum brasilense and glomus intrarradix in sugar cane roots. | fifteen-day-old variety na 56-79 sugar cane seedlings were inoculated with azospirillum brasilense and glomus intrarradix. this article aims at examining changes in sugar cane root seedlings inoculated with glomus intrarradix and azospirillum brasilense, the increase in microbial biomass and the acetylene reduction process as well. the internal root colonization was studied 20 days after inoculation using scanning and a transmission electron microscope. both microorganisms entered the sugar cane ... | 2011 | 23449160 |
| rhizosphere microbial community structure in relation to root location and plant iron nutritional status. | root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. to examine this question, we performed an experiment with barley (hordeum vulgare) plants under iron-limiting and iron-sufficient growth conditions. plants were grown in an iron-limiting soil in root box microcosms. one-half of the plants were treated with foliar iron every day to inhibit phytosiderophore production and to alter ... | 2000 | 10618246 |
| abc transporters involved in export of cell surface glycoconjugates. | complex glycoconjugates play critical roles in the biology of microorganisms. despite the remarkable diversity in glycan structures and the bacteria that produce them, conserved themes are evident in the biosynthesis-export pathways. one of the primary pathways involves representatives of the atp-binding cassette (abc) transporter superfamily. these proteins are responsible for the export of a wide variety of cell surface oligo- and polysaccharides in both gram-positive and gram-negative bacteri ... | 2010 | 20805402 |
| conserved evolutionary units in the heme-copper oxidase superfamily revealed by novel homologous protein families. | the heme-copper oxidase (hco) superfamily includes hcos in aerobic respiratory chains and nitric oxide reductases (nors) in the denitrification pathway. the hco/nor catalytic subunit has a core structure consisting of 12 transmembrane helices (tmhs) arranged in three-fold rotational pseudosymmetry, with six conserved histidines for heme and metal binding. using sensitive sequence similarity searches, we detected a number of novel hco/nor homologs and named them hco homology (hcoh) proteins. seve ... | 2014 | 24931479 |
| domain architectures of sigma54-dependent transcriptional activators. | | 2003 | 12618438 |
| evolution of mitochondria reconstructed from the energy metabolism of living bacteria. | the ancestors of mitochondria, or proto-mitochondria, played a crucial role in the evolution of eukaryotic cells and derived from symbiotic α-proteobacteria which merged with other microorganisms - the basis of the widely accepted endosymbiotic theory. however, the identity and relatives of proto-mitochondria remain elusive. here we show that methylotrophic α-proteobacteria could be the closest living models for mitochondrial ancestors. we reached this conclusion after reconstructing the possibl ... | 2014 | 24804722 |
| ancient origin of the tryptophan operon and the dynamics of evolutionary change. | the seven conserved enzymatic domains required for tryptophan (trp) biosynthesis are encoded in seven genetic regions that are organized differently (whole-pathway operons, multiple partial-pathway operons, and dispersed genes) in prokaryotes. a comparative bioinformatics evaluation of the conservation and organization of the genes of trp biosynthesis in prokaryotic operons should serve as an excellent model for assessing the feasibility of predicting the evolutionary histories of genes and oper ... | 2003 | 12966138 |
| inter-genomic displacement via lateral gene transfer of bacterial trp operons in an overall context of vertical genealogy. | the growing conviction that lateral gene transfer plays a significant role in prokaryote genealogy opens up a need for comprehensive evaluations of gene-enzyme systems on a case-by-case basis. genes of tryptophan biosynthesis are frequently organized as whole-pathway operons, an attribute that is expected to facilitate multi-gene transfer in a single step. we have asked whether events of lateral gene transfer are sufficient to have obscured our ability to track the vertical genealogy that underp ... | 2004 | 15214963 |
| upward mobility and alternative lifestyles: a report from the 10th biennial meeting on bacterial locomotion and signal transduction. | this past january, in cuernavaca mexico, a conglomerate of scientists met to discuss the contemporary view of bacterial locomotion and signal transduction (blast). the blast meetings represent a field that has its roots in chemotaxis and the flagellum-based motility but now encompass all types of cellular movement and signalling. the topics varied from the interactions between molecules to the interactions between species. we heard about 3d reconstructions of transmembrane chemoreceptors within ... | 2009 | 19496930 |
| cyclic di-gmp: the first 25 years of a universal bacterial second messenger. | twenty-five years have passed since the discovery of cyclic dimeric (3'→5') gmp (cyclic di-gmp or c-di-gmp). from the relative obscurity of an allosteric activator of a bacterial cellulose synthase, c-di-gmp has emerged as one of the most common and important bacterial second messengers. cyclic di-gmp has been shown to regulate biofilm formation, motility, virulence, the cell cycle, differentiation, and other processes. most c-di-gmp-dependent signaling pathways control the ability of bacteria t ... | 2013 | 23471616 |
| fifty ways to inhibit motility via cyclic di-gmp: the emerging pseudomonas aeruginosa swarming story. | there are numerous ways by which cyclic dimeric gmp (c-di-gmp) inhibits motility. kuchma et al. (s. l. kuchma, n. j. delalez, l. m. filkins, e. a. snavely, j. p. armitage, and g. a. o'toole, j. bacteriol. 197:420-430, 2015, http://dx.doi.org/10.1128/jb.02130-14) offer a new, previously unseen way of swarming motility inhibition in pseudomonas aeruginosa pa14. this bacterium possesses a single flagellum with one rotor and two sets of stators, only one of which can provide torque for swarming. the ... | 2014 | 25448814 |
| fifty ways to inhibit motility via cyclic di-gmp: the emerging pseudomonas aeruginosa swarming story. | there are numerous ways by which cyclic dimeric gmp (c-di-gmp) inhibits motility. kuchma et al. (s. l. kuchma, n. j. delalez, l. m. filkins, e. a. snavely, j. p. armitage, and g. a. o'toole, j. bacteriol. 197:420-430, 2015, http://dx.doi.org/10.1128/jb.02130-14) offer a new, previously unseen way of swarming motility inhibition in pseudomonas aeruginosa pa14. this bacterium possesses a single flagellum with one rotor and two sets of stators, only one of which can provide torque for swarming. the ... | 2014 | 25448814 |
| cyclic di-gmp regulates multiple cellular functions in the symbiotic alphaproteobacterium sinorhizobium meliloti. | sinorhizobium meliloti undergoes major lifestyle changes between planktonic states, biofilm formation, and symbiosis with leguminous plant hosts. in many bacteria, the second messenger 3',5'-cyclic di-gmp (c-di-gmp, or cdg) promotes a sessile lifestyle by regulating a plethora of processes involved in biofilm formation, including motility and biosynthesis of exopolysaccharides (eps). here, we systematically investigated the role of cdg in s. meliloti rm2011 encoding 22 proteins putatively associ ... | 2016 | 26574513 |
| carbohydrate metabolism in archaea: current insights into unusual enzymes and pathways and their regulation. | the metabolism of archaea, the third domain of life, resembles in its complexity those of bacteria and lower eukarya. however, this metabolic complexity in archaea is accompanied by the absence of many "classical" pathways, particularly in central carbohydrate metabolism. instead, archaea are characterized by the presence of unique, modified variants of classical pathways such as the embden-meyerhof-parnas (emp) pathway and the entner-doudoroff (ed) pathway. the pentose phosphate pathway is only ... | 2014 | 24600042 |