Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| removal of chromium using rhizobium leguminosarum. | the chromium (cr(iii) and cr(vi)) removal capability of rhizobium leguminosarum was checked by estimating the amount of chromium in the medium before and after inoculation. to determine the efficiency of r. leguminosarum in removal of chromium, the influence of physical and chemical parameters such as temperature, ph and different concentrations (0.1-1.0 mm) of trivalent (cr(iii)) and hexavalent (cr(vi)) chromium were studied. the chromium removal in aqueous solution by different size of active ... | 2012 | 22806858 |
| the abc transporters in candidatus liberibacter asiaticus. | candidatus liberibacter asiaticus (ca. l. asiaticus) is a gram-negative bacterium and the pathogen of citrus greening disease (huanglongbing, hlb). as a parasitic bacterium, ca. l. asiaticus harbors abc transporters that play important roles in exchanging chemical compounds between ca. l. asiaticus and its host. here, we analyzed all the abc transporter-related proteins in ca. l. asiaticus. we identified 14 abc transporter systems and predicted their structures and substrate specificities. in-de ... | 2012 | 22807026 |
| molecular characterization of nad+-dependent dna ligase from wolbachia endosymbiont of lymphatic filarial parasite brugia malayi. | the lymphatic filarial parasite, brugia malayi contains wolbachia endobacteria that are essential for development, viability and fertility of the parasite. therefore, wolbachial proteins have been currently seen as the potential antifilarial drug targets. nad(+)-dependent dna ligase is characterized as a promising drug target in several organisms due to its crucial, indispensable role in dna replication, recombination and dna repair. we report here the cloning, expression and purification of nad ... | 2012 | 22815933 |
| regulatable vectors for environmental gene expression in alphaproteobacteria. | two expression vectors utilizing the inducible taurine promoter (tauap) were developed. plasmid plmb51 is a stable low-copy vector enabling expression in the environment and in planta. the higher copy number plmb509 enables bd restriction-independent cloning, expression, and purification of polyhistidine-tagged proteins. | 2012 | 22820336 |
| quorum sensing: how bacteria can coordinate activity and synchronize their response to external signals? | quorum sensing is used by a large variety of bacteria to regulate gene expression in a cell-density-dependent manner. bacteria can synchronize population behavior using small molecules called autoinducers that are produced by cognate synthases and recognized by specific receptors. quorum sensing plays critical roles in regulating diverse cellular functions in bacteria, including bioluminescence, virulence gene expression, biofilm formation, and antibiotic resistance. the best-studied autoinducer ... | 2012 | 22825856 |
| unconventional initiator trnas sustain escherichia coli. | of all trnas, initiator trna is unique in its ability to start protein synthesis by directly binding the ribosomal p-site. this ability is believed to derive from the almost universal presence of three consecutive g-c base (3g-c) pairs in the anticodon stem of initiator trna. consistent with the hypothesis, a plasmid-borne initiator trna with one, two, or all 3g-c pairs mutated displays negligible initiation activity when tested in a wt escherichia coli cell. given this, the occurrence of unconv ... | 2012 | 22829667 |
| the nsrr regulon in nitrosative stress resistance of salmonella enterica serovar typhimurium. | nitric oxide (no·) is an important mediator of innate immunity. the facultative intracellular pathogen salmonella has evolved mechanisms to detoxify and evade the antimicrobial actions of host-derived no· produced during infection. expression of the no·-detoxifying flavohaemoglobin hmp is controlled by the no·-sensing transcriptional repressor nsrr and is required for salmonella virulence. in this study we show that nsrr responds to very low no· concentrations, suggesting that it plays a primary ... | 2012 | 22831173 |
| comparative molecular analysis of chemolithoautotrophic bacterial diversity and community structure from coastal saline soils, gujarat, india. | soils harbour high diversity of obligate as well as facultative chemolithoautotrophic bacteria that contribute significantly to co2 dynamics in soil. in this study, we used culture dependent and independent methods to assess the community structure and diversity of chemolithoautotrophs in agricultural and coastal barren saline soils (low and high salinity). we studied the composition and distribution of chemolithoautotrophs by means of functional marker gene cbbl encoding large subunit of ribulo ... | 2012 | 22834535 |
| oligogalacturonides: novel signaling molecules in rhizobium-legume communications. | oligogalacturonides are pectic fragments of the plant cell wall, whose signaling role has been described thus far during plant development and plant-pathogen interactions. in the present work, we evaluated the potential involvement of oligogalacturonides in the molecular communications between legumes and rhizobia during the establishment of nitrogen-fixing symbiosis. oligogalacturonides with a degree of polymerization of 10 to 15 were found to trigger a rapid intracellular production of reactiv ... | 2012 | 22835276 |
| characterization of the twin-arginine transport secretome in sinorhizobium meliloti and evidence for host-dependent phenotypes. | the twin-arginine transport (tat) system is essential for cell viability in sinorhizobium meliloti and may play a role during the development of root nodules. utilizing an in vivo recombination strategy, we have constructed 28 strains that contain deletions in predicted tat substrates. testing of these mutations for symbiotic proficiency on the plant hosts alfalfa and sweet clover shows that some of these mutations affect associations with these hosts differentially. | 2012 | 22843517 |
| genetic analysis reveals links between lipid a structure and expression of the outer membrane protein gene, ropb, in rhizobium leguminosarum. | the fabxl genes encode enzymes that synthesize the very-long-chain fatty acid - a unique acyl modification located at the 2' position of the lipid a of gram-negative bacteria in the order rhizobiales. mutation of the fabxl genes causes sensitivity to outer membrane stressors and other envelope-related stresses; however, the underlying mechanisms for increased sensitivity are poorly understood. we found that expression of the outer membrane protein gene ropb is down-regulated in an acpxl mutant. ... | 2012 | 22845832 |
| attenuation of quorum sensing in the pathogen acinetobacter baumannii using non-native n-acyl homoserine lactones. | many bacterial pathogens use quorum sensing (qs) to control virulence. as a result, the development of methods to intercept qs has attracted significant interest as a potential anti-infective therapy. acinetobacter baumannii has emerged as a pan-drug-resistant pathogen and displays a remarkable ability to persist in hospital settings despite desiccation and antimicrobial treatment. recent studies have shown that a. baumannii qs mutants have limited motility and fail to form mature biofilms; thes ... | 2012 | 22853441 |
| minimum requirements of flagellation and motility for infection of agrobacterium sp. strain h13-3 by flagellotropic bacteriophage 7-7-1. | the flagellotropic phage 7-7-1 specifically adsorbs to agrobacterium sp. strain h13-3 (formerly rhizobium lupini h13-3) flagella for efficient host infection. the agrobacterium sp. h13-3 flagellum is complex and consists of three flagellin proteins: the primary flagellin flaa, which is essential for motility, and the secondary flagellins flab and flad, which have minor functions in motility. using quantitative infectivity assays, we showed that absence of flad had no effect on phage infection, w ... | 2012 | 22865074 |
| structure of a specialized acyl carrier protein essential for lipid a biosynthesis with very long-chain fatty acids in open and closed conformations. | the solution nuclear magnetic resonance (nmr) structures and backbone (15)n dynamics of the specialized acyl carrier protein (acp), rpacpxl, from rhodopseudomonas palustris, in both the apo form and holo form modified by covalent attachment of 4'-phosphopantetheine at s37, are virtually identical, monomeric, and correspond to the closed conformation. the structures have an extra α-helix compared to the archetypical acp from escherichia coli, which has four helices, resulting in a larger opening ... | 2012 | 22876860 |
| role of the irr protein in the regulation of iron metabolism in rhodobacter sphaeroides. | in rhizobia the irr protein is an important regulator for iron-dependent gene expression. we studied the role of the irr homolog rsp_3179 in the photosynthetic alpha-proteobacterium rhodobacter sphaeroides. while irr had little effect on growth under iron-limiting or non-limiting conditions its deletion resulted in increased resistance to hydrogen peroxide and singlet oxygen. this correlates with an elevated expression of kate for catalase in the irr mutant compared to the wild type under non-st ... | 2012 | 22879920 |
| aggregation by depletion attraction in cultures of bacteria producing exopolysaccharide. | in bacteria, the production of exopolysaccharides--polysaccharides secreted by the cells into their growth medium--is integral to the formation of aggregates and biofilms. these exopolysaccharides often form part of a matrix that holds the cells together. investigating the bacterium sinorhizobium meliloti, we found that a mutant that overproduces the exopolysaccharide succinoglycan showed enhanced aggregation, resulting in phase separation of the cultures. however, the aggregates did not appear ... | 2012 | 22896568 |
| reactive oxygen species-inducible ecf σ factors of bradyrhizobium japonicum. | extracytoplasmic function (ecf) σ factors control the transcription of genes involved in different cellular functions, such as stress responses, metal homeostasis, virulence-related traits, and cell envelope structure. the genome of bradyrhizobium japonicum, the nitrogen-fixing soybean endosymbiont, encodes 17 putative ecf σ factors belonging to nine different ecf σ factor families. the genes for two of them, ecfq (bll1028) and ecff (blr3038), are highly induced in response to the reactive oxyge ... | 2012 | 22916258 |
| exploring the genetic diversity of ethiopian grass pea (lathyrus sativus l.) using est-ssr markers. | expressed sequence tags (ests) in public databases and cross-species transferable markers are considered to be a cost-effective means for developing sequence-based markers for less-studied species. in this study, est-simple sequence repeat (ssr) markers developed from lathyrus sativus l. est sequences and cross-transferable est-ssrs derived from medicago truncatula l. were utilized to investigate the genetic diversity among grass pea populations from ethiopia. a total of 45 alleles were detected ... | 2011 | 22924019 |
| exploring the genetic diversity of ethiopian grass pea (lathyrus sativus l.) using est-ssr markers. | expressed sequence tags (ests) in public databases and cross-species transferable markers are considered to be a cost-effective means for developing sequence-based markers for less-studied species. in this study, est-simple sequence repeat (ssr) markers developed from lathyrus sativus l. est sequences and cross-transferable est-ssrs derived from medicago truncatula l. were utilized to investigate the genetic diversity among grass pea populations from ethiopia. a total of 45 alleles were detected ... | 2011 | 22924019 |
| comparative genomics of early-diverging brucella strains reveals a novel lipopolysaccharide biosynthesis pathway. | brucella species are gram-negative bacteria that infect mammals. recently, two unusual strains (brucella inopinata bo1(t) and b. inopinata-like bo2) have been isolated from human patients, and their similarity to some atypical brucellae isolated from australian native rodent species was noted. here we present a phylogenomic analysis of the draft genome sequences of bo1(t) and bo2 and of the australian rodent strains 83-13 and nf2653 that shows that they form two groups well separated from the ot ... | 2012 | 22930339 |
| the role of bacterial enhancer binding proteins as specialized activators of σ54-dependent transcription. | bacterial enhancer binding proteins (bebps) are transcriptional activators that assemble as hexameric rings in their active forms and utilize atp hydrolysis to remodel the conformation of rna polymerase containing the alternative sigma factor σ(54). we present a comprehensive and detailed summary of recent advances in our understanding of how these specialized molecular machines function. the review is structured by introducing each of the three domains in turn: the central catalytic domain, the ... | 2012 | 22933558 |
| polymorphic infection and organogenesis patterns induced by a rhizobium leguminosarum isolate from lotus root nodules are determined by the host genotype. | to sample the natural variation in genes controlling compatibility in the legume-rhizobium symbiosis, we isolated rhizobia from nodules of endemic lotus species from 21 sites across europe. the majority of isolates were identified as mesorhizobium- or bradyrhizobium-related and formed nitrogen-fixing root nodules on lotus corniculatus and l. pendunculatus, respectively, thus confirming previously defined cross-inoculation groups. rhizobium leguminosarum (rl) strain norway, isolated from l. corni ... | 2012 | 22950721 |
| "ménage à trois": the presence/absence of thyme shapes the mutualistic interaction between the host plant medicago truncatula (fabaceae) and its symbiotic bacterium sinorhizobium meliloti. | the long-term maintenance of specialized mutualisms remains an evolutionary puzzle. recent focus has been on factors governing the stability of these mutualisms, including sanctions by the host, partner choice, and coevolutionary constraint, that is, the genetic correlation (r(g)) between fitness of both partners. so far these studies have been typically carried out in a single environment. here, we ask if the genetic correlation between fitness of the host plant medicago truncatula (fabaceae) a ... | 2012 | 22957171 |
| specific metal recognition in nickel trafficking. | nickel is an essential metal for a number of bacterial species that have developed systems for acquiring, delivering, and incorporating the metal into target enzymes and controlling the levels of nickel in cells to prevent toxic effects. as with other transition metals, these trafficking systems must be able to distinguish between the desired metal and other transition metal ions with similar physical and chemical properties. because there are few enzymes (targets) that require nickel for activi ... | 2012 | 22970729 |
| role of rhizobium endoglucanase celc2 in cellulose biosynthesis and biofilm formation on plant roots and abiotic surfaces. | the synthesis of cellulose is among the most important but poorly understood biochemical processes, especially in bacteria, due to its complexity and high degree of regulation. in this study, we analyzed both the production of cellulose by all known members of the rhizobiaceae and the diversity of rhizobium celabc operon predicted to be involved in cellulose biosynthesis. we also investigated the involvement in cellulose production and biofilm formation of celc gene encoding an endoglucanase (ce ... | 2012 | 22970813 |
| simple and efficient methods to generate split roots and grafted plants useful for long-distance signaling studies in medicago truncatula and other small plants. | 2012 | 22971438 | |
| characterization of the genome, proteome, and structure of yersiniophage ϕr1-37. | the bacteriophage vb_yecm-ϕr1-37 (ϕr1-37) is a lytic yersiniophage that can propagate naturally in different yersinia species carrying the correct lipopolysaccharide receptor. this large-tailed phage has deoxyuridine (du) instead of thymidine in its dna. in this study, we determined the genomic sequence of phage ϕr1-37, mapped parts of the phage transcriptome, characterized the phage particle proteome, and characterized the virion structure by cryo-electron microscopy and image reconstruction. t ... | 2012 | 22973030 |
| the repac replication system of the rhizobium leguminosarum prl7 plasmid is functional: implications regarding the origin and evolution of repabc plasmids. | the repabc replication/partitioning systems are commonly found in alpha-proteobacteria plasmids and in secondary chromosomes. all of the elements required for their replication and stable maintenance are encoded within a single transcription unit: the repabc operon. the repc gene encodes an initiator protein, while repa, repb and centromere-like sequence (pars) direct plasmid segregation. strains containing two or more repabc plasmids are a common feature in some alpha proteobacteria groups, ind ... | 2013 | 22975386 |
| extracytoplasmic function (ecf) sigma factor σf is involved in caulobacter crescentus response to heavy metal stress. | the α-proteobacterium caulobacter crescentus inhabits low-nutrient environments and can tolerate certain levels of heavy metals in these sites. it has been reported that c. crescentus responds to exposure to various heavy metals by altering the expression of a large number of genes. | 2012 | 22985357 |
| identifying abnormalities in symbiotic development between trifolium spp. and rhizobium leguminosarum bv. trifolii leading to sub-optimal and ineffective nodule phenotypes. | legumes overcome nitrogen limitations by entering into a mutualistic symbiosis with n(2)-fixing bacteria (rhizobia). fully compatible associations (effective) between trifolium spp. and rhizobium leguminosarum bv. trifolii result from successful recognition of symbiotic partners in the rhizosphere, root hair infection and the formation of nodules where n(2)-fixing bacteroids reside. poorly compatible associations can result in root nodule formation with minimal (sub-optimal) or no (ineffective) ... | 2012 | 22989463 |
| metallation and mismetallation of iron and manganese proteins in vitro and in vivo: the class i ribonucleotide reductases as a case study. | how cells ensure correct metallation of a given protein and whether a degree of promiscuity in metal binding has evolved are largely unanswered questions. in a classic case, iron- and manganese-dependent superoxide dismutases (sods) catalyze the disproportionation of superoxide using highly similar protein scaffolds and nearly identical active sites. however, most of these enzymes are active with only one metal, although both metals can bind in vitro and in vivo. iron(ii) and manganese(ii) bind ... | 2012 | 22991063 |
| emerging themes in seca2-mediated protein export. | the conserved general secretion (sec) pathway carries out most protein export in bacteria and is powered by the essential atpase seca. interestingly, mycobacteria and some gram-positive bacteria possess two seca proteins: seca1 and seca2. in these species, seca1 is responsible for exporting most proteins, whereas seca2 exports only a subset of substrates and is implicated in virulence. however, despite the impressive body of knowledge about the canonical seca1, less is known concerning seca2 fun ... | 2012 | 23000954 |
| 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 |
| mining the sinorhizobium meliloti transportome to develop fret biosensors for sugars, dicarboxylates and cyclic polyols. | förster resonance energy transfer (fret) biosensors are powerful tools to detect biologically important ligands in real time. currently fret bisosensors are available for twenty-two compounds distributed in eight classes of chemicals (two pentoses, two hexoses, two disaccharides, four amino acids, one nucleobase, two nucleotides, six ions and three phytoestrogens). to expand the number of available fret biosensors we used the induction profile of the sinorhizobium meliloti transportome to system ... | 2012 | 23028462 |
| robust markers reflecting phylogeny and taxonomy of rhizobia. | genomic ani (average nucleotide identity) has been found to be able to replace dna-dna hybridization in prokaryote taxonomy. the ani of each of the core genes that has a phylogeny congruent with the reference species tree of rhizobia was compared to the genomic ani. this allowed us to identify three housekeeping genes (smc00019-trua-thra) whose ani reflected the intraspecies and interspecies genomic ani among rhizobial strains, revealing an ani gap (≥2%) between the inter- and intra-species comp ... | 2012 | 23028691 |
| calcium causes multimerization of the large adhesin lapf and modulates biofilm formation by pseudomonas putida. | lapf is a large secreted protein involved in microcolony formation and biofilm maturation in pseudomonas putida. its c-terminal domain shows the characteristics of proteins secreted through a type i secretion system and includes a predicted calcium binding motif. we provide experimental evidence of specific binding of ca(2+) to the purified c-terminal domain of lapf (clapf). calcium promotes the formation of large aggregates, which disappear in the presence of the calcium chelator egta. immunolo ... | 2012 | 23042991 |
| characterization of nitric oxide-inducing lipid a derived from mesorhizobium loti lipopolysaccharide. | mesorhizobium loti is a member of the rhizobia and forms nitrogen-fixing symbioses with several lotus species. recently, it was reported that m. loti bacterial cells and their lipopolysaccharide (lps) preparations transiently induced nitric oxide (no) production in the roots of l. japonicus. we subsequently found that polysaccharides and the lipid a moiety were responsible for this no induction. in this study, we elucidated the chemical structure of m. loti lipid a and characterized its no-induc ... | 2012 | 23059724 |
| phosphorus limitation increases attachment in agrobacterium tumefaciens and reveals a conditional functional redundancy in adhesin biosynthesis. | bacterial responses to phosphorus limitation, commonly inorganic phosphate (p(i)), are important survival mechanisms in a variety of environments. the two-component sensor kinase phor and its cognate response regulator phob are central to the p(i) limitation response of many bacteria and control the large pho regulon. limitation for p(i) significantly increased attachment and biofilm formation by the plant pathogen agrobacterium tumefaciens, and this was driven by phob. surprisingly, it was also ... | 2012 | 23103488 |
| mucosal immunization with live attenuated francisella novicida u112δiglb protects against pulmonary f. tularensis schu s4 in the fischer 344 rat model. | the need for an efficacious vaccine against francisella tularensis is a consequence of its low infectious dose and high mortality rate if left untreated. this study sought to characterize a live attenuated subspecies novicida-based vaccine strain (u112δiglb) in an established second rodent model of pulmonary tularemia, namely the fischer 344 rat using two distinct routes of vaccination (intratracheal [i.t.] and oral). attenuation was verified by comparing replication of u112δiglb with wild type ... | 2012 | 23118885 |
| quantitative proteomic analysis of the hfq-regulon in sinorhizobium meliloti 2011. | riboregulation stands for rna-based control of gene expression. in bacteria, small non-coding rnas (srnas) are a major class of riboregulatory elements, most of which act at the post-transcriptional level by base-pairing target mrna genes. the rna chaperone hfq facilitates antisense interactions between target mrnas and regulatory srnas, thus influencing mrna stability and/or translation rate. in the α-proteobacterium sinorhizobium meliloti strain 2011, the identification and detection of multip ... | 2012 | 23119037 |
| 2-nitrobenzoate 2-nitroreductase (nbaa) switches its substrate specificity from 2-nitrobenzoic acid to 2,4-dinitrobenzoic acid under oxidizing conditions. | 2-nitrobenzoate 2-nitroreductase (nbaa) of pseudomonas fluorescens strain ku-7 is a unique enzyme, transforming 2-nitrobenzoic acid (2-nba) and 2,4-dinitrobenzoic acid (2,4-dnba) to the 2-hydroxylamine compounds. sequence comparison reveals that nbaa contains a conserved cysteine residue at position 141 and two variable regions at amino acids 65 to 74 and 193 to 216. the truncated mutant δ65-74 exhibited markedly reduced activity toward 2,4-dnba, but its 2-nba reduction activity was unaffected; ... | 2013 | 23123905 |
| revised phylogeny and novel horizontally acquired virulence determinants of the model soft rot phytopathogen pectobacterium wasabiae scc3193. | soft rot disease is economically one of the most devastating bacterial diseases affecting plants worldwide. in this study, we present novel insights into the phylogeny and virulence of the soft rot model pectobacterium sp. scc3193, which was isolated from a diseased potato stem in finland in the early 1980s. genomic approaches, including proteome and genome comparisons of all sequenced soft rot bacteria, revealed that scc3193, previously included in the species pectobacterium carotovorum, can no ... | 2012 | 23133391 |
| dual role of hupf in the biosynthesis of [nife] hydrogenase in rhizobium leguminosarum. | [nife] hydrogenases are enzymes that catalyze the oxidation of hydrogen into protons and electrons, to use h₂ as energy source, or the production of hydrogen through proton reduction, as an escape valve for the excess of reduction equivalents in anaerobic metabolism. biosynthesis of [nife] hydrogenases is a complex process that occurs in the cytoplasm, where a number of auxiliary proteins are required to synthesize and insert the metal cofactors into the enzyme structural units. the endosymbioti ... | 2012 | 23136881 |
| genetic characterization of a novel rhizobial plasmid conjugation system in rhizobium leguminosarum bv. viciae strain vf39sm. | rhizobium leguminosarum strain vf39sm contains two plasmids that have previously been shown to be self-transmissible by conjugation. one of these plasmids, prlevf39b, is shown in this study to carry a set of plasmid transfer genes that differs significantly from conjugation systems previously studied in the rhizobia but is similar to an uncharacterized set of genes found in r. leguminosarum bv. trifolii strain wsm2304. the entire sequence of the transfer region on prlevf39b was determined as par ... | 2013 | 23144250 |
| whole genome analysis of leptospira licerasiae provides insight into leptospiral evolution and pathogenicity. | the whole genome analysis of two strains of the first intermediately pathogenic leptospiral species to be sequenced (leptospira licerasiae strains var010 and mmd0835) provides insight into their pathogenic potential and deepens our understanding of leptospiral evolution. comparative analysis of eight leptospiral genomes shows the existence of a core leptospiral genome comprising 1547 genes and 452 conserved genes restricted to infectious species (including l. licerasiae) that are likely to be pa ... | 2012 | 23145189 |
| polysac3db: an annotated data base of 3 dimensional structures of polysaccharides. | polysaccharides are ubiquitously present in the living world. their structural versatility makes them important and interesting components in numerous biological and technological processes ranging from structural stabilization to a variety of immunologically important molecular recognition events. the knowledge of polysaccharide three-dimensional (3d) structure is important in studying carbohydrate-mediated host-pathogen interactions, interactions with other bio-macromolecules, drug design and ... | 2012 | 23151233 |
| relevance of fucose-rich extracellular polysaccharides produced by rhizobium sullae strains nodulating hedysarum coronarium l. legumes. | specific and complex interactions between soil bacteria, known as rhizobia, and their leguminous host plants result in the development of root nodules. this process implies a complex dialogue between the partners. rhizobia synthesize different classes of polysaccharides: exopolysaccharides (eps), kdo-rich capsular polysaccharides, lipopolysaccharides, and cyclic β-(1,2)-glucans. these polymers are actors of a successful symbiosis with legumes. we focus here on studying the eps produced by rhizob ... | 2013 | 23183977 |
| prokaryotic caspase homologs: phylogenetic patterns and functional characteristics reveal considerable diversity. | caspases accomplish initiation and execution of apoptosis, a programmed cell death process specific to metazoans. the existence of prokaryotic caspase homologs, termed metacaspases, has been known for slightly more than a decade. despite their potential connection to the evolution of programmed cell death in eukaryotes, the phylogenetic distribution and functions of these prokaryotic metacaspase sequences are largely uncharted, while a few experiments imply involvement in programmed cell death. ... | 2012 | 23185476 |
| manganese uptake in marine bacteria; the novel mntx transporter is widespread in roseobacters, vibrios, alteromonadales and the sar11 and sar116 clades. | we showed that two very different manganese transporters occur in various important genera of marine bacteria. the abc transporter encoded by sitabcd of the model roseobacter-clade bacterium ruegeria pomeroyi dss-3 is required for mn(2+) import and was repressed by the mur (manganese uptake regulator) transcriptional regulator in mn-replete media. most genome-sequenced roseobacter strains contain sitabcd, which are in at least two sub-groups, judged by their amino-acid sequences. however, a few ... | 2012 | 23190726 |
| manganese uptake in marine bacteria; the novel mntx transporter is widespread in roseobacters, vibrios, alteromonadales and the sar11 and sar116 clades. | we showed that two very different manganese transporters occur in various important genera of marine bacteria. the abc transporter encoded by sitabcd of the model roseobacter-clade bacterium ruegeria pomeroyi dss-3 is required for mn(2+) import and was repressed by the mur (manganese uptake regulator) transcriptional regulator in mn-replete media. most genome-sequenced roseobacter strains contain sitabcd, which are in at least two sub-groups, judged by their amino-acid sequences. however, a few ... | 2012 | 23190726 |
| the effect of high concentrations of glucose and fructose on the respiration rate of isolated rhizobium leguminosarum bacteroids. | the effect of high concentrations of glucose and fructose on the respiration rate of rhizobium leguminosarum bacteroids isolated from nodules of pisum sativum was investigated. high concentrations of glucose and fructose stimulated the respiration rate of the bacteroids. fructose stimulated the respiration rate to a higher extent than glucose. malate in a concentration of 1 mm increased the respiration rate of bacteroids to a high level. with bacteroids suspended in a medium with a high concentr ... | 1984 | 23195155 |
| protein export by the mycobacterial seca2 system is determined by the preprotein mature domain. | at the core of the bacterial general secretion (sec) pathway is the seca atpase, which powers translocation of unfolded preproteins containing sec signal sequences through the secyeg membrane channel. mycobacteria have two nonredundant seca homologs: seca1 and seca2. while the essential seca1 handles "housekeeping" export, the nonessential seca2 exports a subset of proteins and is required for mycobacterium tuberculosis virulence. currently, it is not understood how seca2 contributes to sec expo ... | 2013 | 23204463 |
| draft genome sequence of agrobacterium albertimagni strain aol15. | agrobacterium albertimagni strain aol15 is an alphaproteobacterium isolated from arsenite-oxidizing biofilms whose draft genome contains 5.1 mb in 55 contigs with 61.2% gc content and includes a 21-gene arsenic gene island. this is the first available genome for this species and the second agrobacterium arsenic gene island. | 2012 | 23209236 |
| unique secreted-surface protein complex of lactobacillus rhamnosus, identified by phage display. | proteins are the most diverse structures on bacterial surfaces; hence, they are candidates for species- and strain-specific interactions of bacteria with the host, environment, and other microorganisms. genomics has decoded thousands of bacterial surface and secreted proteins, yet the function of most cannot be predicted because of the enormous variability and a lack of experimental data that would allow deduction of function through homology. here, we used phage display to identify a pair of in ... | 2012 | 23233310 |
| unique secreted-surface protein complex of lactobacillus rhamnosus, identified by phage display. | proteins are the most diverse structures on bacterial surfaces; hence, they are candidates for species- and strain-specific interactions of bacteria with the host, environment, and other microorganisms. genomics has decoded thousands of bacterial surface and secreted proteins, yet the function of most cannot be predicted because of the enormous variability and a lack of experimental data that would allow deduction of function through homology. here, we used phage display to identify a pair of in ... | 2012 | 23233310 |
| rapa2 is a calcium-binding lectin composed of two highly conserved cadherin-like domains that specifically recognize rhizobium leguminosarum acidic exopolysaccharides. | in silico analyses have revealed a conserved protein domain (chdl) widely present in bacteria that has significant structural similarity to eukaryotic cadherins. a chdl domain was shown to be present in rapa, a protein that is involved in autoaggregation of rhizobium cells, biofilm formation, and adhesion to plant roots as shown by us and others. structural similarity to cadherins suggested calcium-dependent oligomerization of chdl domains as a mechanistic basis for rapa action. here we show by ... | 2012 | 23235153 |
| rapa2 is a calcium-binding lectin composed of two highly conserved cadherin-like domains that specifically recognize rhizobium leguminosarum acidic exopolysaccharides. | in silico analyses have revealed a conserved protein domain (chdl) widely present in bacteria that has significant structural similarity to eukaryotic cadherins. a chdl domain was shown to be present in rapa, a protein that is involved in autoaggregation of rhizobium cells, biofilm formation, and adhesion to plant roots as shown by us and others. structural similarity to cadherins suggested calcium-dependent oligomerization of chdl domains as a mechanistic basis for rapa action. here we show by ... | 2012 | 23235153 |
| plasticity of rhizosphere hydraulic properties as a key for efficient utilization of scarce resources. | it is known that the soil near roots, the so-called rhizosphere, has physical and chemical properties different from those of the bulk soil. rhizosphere properties are the result of several processes: root and soil shrinking/swelling during drying/wetting cycles, soil compaction by root growth, mucilage exuded by root caps, interaction of mucilage with soil particles, mucilage shrinking/swelling and mucilage biodegradation. these processes may lead to variable rhizosphere properties, i.e. the pr ... | 2012 | 23235697 |
| plasticity of rhizosphere hydraulic properties as a key for efficient utilization of scarce resources. | it is known that the soil near roots, the so-called rhizosphere, has physical and chemical properties different from those of the bulk soil. rhizosphere properties are the result of several processes: root and soil shrinking/swelling during drying/wetting cycles, soil compaction by root growth, mucilage exuded by root caps, interaction of mucilage with soil particles, mucilage shrinking/swelling and mucilage biodegradation. these processes may lead to variable rhizosphere properties, i.e. the pr ... | 2012 | 23235697 |
| how does pea architecture influence light sharing in virtual wheat-pea mixtures? a simulation study based on pea genotypes with contrasting architectures. | light interception is a key factor driving the functioning of wheat-pea intercrops. the sharing of light is related to the canopy structure, which results from the architectural parameters of the mixed species. in the present study, we characterized six contrasting pea genotypes and identified architectural parameters whose range of variability leads to various levels of light sharing within virtual wheat-pea mixtures. | 2012 | 23240074 |
| homo- and heterotypic interactions between pss proteins involved in the exopolysaccharide transport system in rhizobium leguminosarum bv. trifolii. | rhizobium leguminosarum produces large amounts of exopolysaccharide (eps) that has been shown to be an important determinant of successful nitrogen-fixing symbiosis with legume plants. eps is assembled in a wzx/wzy-dependent manner, and proteins involved in the process are proposed to form a complex that enables coupling the synthesis of eps subunits with their polymerization and transport. pss proteins, which are encoded within the chromosomal polysaccharide synthesis cluster of rhizobium legum ... | 2013 | 23241669 |
| identification and phylogenetic characterization of cobalamin biosynthetic genes of ensifer adhaerens. | ensifer adhaerens csba was screened as a cobalamin producer. the draft genome sequence revealed that the strain possesses 22 cobalamin biosynthetic genes (cob genes). the cob gene arrangement on the genome of e. adhaerens csba was similar to that of other ensifer species, and most similar to that of pseudomonas denitrificans sc510. the cobn sequence phylogeny was generally congruent with that of the 16s rrna gene, and it is suggeted that e. adhaerens csba might have inherited the cob genes from ... | 2012 | 23257908 |
| identification and phylogenetic characterization of cobalamin biosynthetic genes of ensifer adhaerens. | ensifer adhaerens csba was screened as a cobalamin producer. the draft genome sequence revealed that the strain possesses 22 cobalamin biosynthetic genes (cob genes). the cob gene arrangement on the genome of e. adhaerens csba was similar to that of other ensifer species, and most similar to that of pseudomonas denitrificans sc510. the cobn sequence phylogeny was generally congruent with that of the 16s rrna gene, and it is suggeted that e. adhaerens csba might have inherited the cob genes from ... | 2012 | 23257908 |
| 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 |
| 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 |
| elucidation of a novel lipid a α-(1,1)-gala transferase gene (rgtf) from mesorhizobium loti: heterologous expression of rgtf causes rhizobium etli to synthesize lipid a with α-(1,1)-gala. | an unusual α-(1,1)-galacturonic acid (gala) lipid a modification has been reported in the lipopolysaccharide of a number of interesting gram-negative bacteria, including the nitrogen-fixing bacteria azospirillum lipoferum, mesorhizobium huakuii and m. loti, the stalk-forming bacterium caulobacter crescentus and the hyperthermophilic bacterium aquifex aeolicus. however, the α-(1,1)-gala transferase (galat) gene, which we have named rgtf, was not identified. species of the rhizobium genera produce ... | 2013 | 23283001 |
| strigolactones: internal and external signals in plant symbioses? | as the newest plant hormone, strigolactone research is undergoing an exciting expansion. in less than five years, roles for strigolactones have been defined in shoot branching, secondary growth, root growth and nodulation, to add to the growing understanding of their role in arbuscular mycorrhizae and parasitic weed interactions. strigolactones are particularly fascinating as signaling molecules as they can act both inside the plant as an endogenous hormone and in the soil as a rhizosphere signa ... | 2013 | 23299321 |
| permanent residents or temporary lodgers: characterizing intracellular bacterial communities in the siphonous green alga bryopsis. | the ecological success of giant celled, siphonous green algae in coastal habitats has repeatedly been linked to endophytic bacteria living within the cytoplasm of the hosts. yet, very little is known about the relative importance of evolutionary and ecological factors controlling the intracellular bacterial flora of these seaweeds. using the marine alga bryopsis (bryopsidales, chlorophyta) as a model, we explore the diversity of the intracellular bacterial communities and investigate whether the ... | 2013 | 23303543 |
| construction of a marker system for the evaluation of competitiveness for legume nodulation in rhizobium strains. | a marker system has been set up for the analysis of competitiveness of rhizobium leguminosarum strains for legume nodulation. the strains generated incorporate gusa and celb marker genes at identical positions and allow efficient scoring of single and double infections. based on this system, we have found that strain upm791 outcompetes 3841 for nodulation in pea. this technique will be useful to determine the effect of different traits on competitiveness. | 2013 | 23305927 |
| sequence analysis of hypothetical lysine exporter genes of rhizobium leguminosarum bv. trifolii from calamine old waste heaps and their evolutionary history. | the aim of this study was to identify heavy metal detoxification system in rhizobium leguminosarum bv. trifolii isolated from trifolium repens inhabiting old (70-100 years) zn-pb waste heaps in poland by pcr reaction with czcd1 and czcd2 primers. by sequence analysis, four different genotypes of obtained amplicons were identified among eight examined isolates. their sequence similarity ranged 91-99 %. they indicated the highest sequence identity to the hypothetical lysine exporter gene of r. leg ... | 2013 | 23322256 |
| directed construction and analysis of a sinorhizobium meliloti psyma deletion mutant library. | resources from the sinorhizobium meliloti rm1021 open reading frame (orf) plasmid libraries were used in a medium-throughput method to construct a set of 50 overlapping deletion mutants covering all of the rm1021 psyma megaplasmid except the replicon region. each resulting psyma derivative carried a defined deletion of approximately 25 orfs. various phenotypes, including cytochrome c respiration activity, the ability of the mutants to grow on various carbon and nitrogen sources, and the symbioti ... | 2013 | 23335760 |
| isolation and structural identification of the trihydroxamate siderophore vicibactin and its degradative products from rhizobium leguminosarum atcc 14479 bv. trifolii. | the rhizobia are a group of free-living soil bacteria known for their ability to symbiotically infect the roots of specific host plants as well as to produce siderophores in order to compete with other microorganisms for the limited availability of iron in the rhizosphere. in this study, rhizobium leguminosarum atcc 14479, which preferentially infects the red clover trifolium pratense, was found to produce the trihydroxamate siderophore vicibactin (c33h55n6o15) under iron restricted conditions. ... | 2013 | 23361163 |
| genomic and functional analysis of the type vi secretion system in acinetobacter. | the genus acinetobacter is comprised of a diverse group of species, several of which have raised interest due to potential applications in bioremediation and agricultural purposes. in this work, we show that many species within the genus acinetobacter possess the genetic requirements to assemble a functional type vi secretion system (t6ss). this secretion system is widespread among gram negative bacteria, and can be used for toxicity against other bacteria and eukaryotic cells. the most studied ... | 2013 | 23365692 |
| involvement of a bacterial microcompartment in the metabolism of fucose and rhamnose by clostridium phytofermentans. | clostridium phytofermentans, an anaerobic soil bacterium, can directly convert plant biomass into biofuels. the genome of c. phytofermentans contains three loci with genes encoding shell proteins of bacterial microcompartments (bmc), organelles composed entirely of proteins. | 2013 | 23382892 |
| root exudation of phytochemicals in arabidopsis follows specific patterns that are developmentally programmed and correlate with soil microbial functions. | plant roots constantly secrete compounds into the soil to interact with neighboring organisms presumably to gain certain functional advantages at different stages of development. accordingly, it has been hypothesized that the phytochemical composition present in the root exudates changes over the course of the lifespan of a plant. here, root exudates of in vitro grown arabidopsis plants were collected at different developmental stages and analyzed using gc-ms. principle component analysis reveal ... | 2013 | 23383346 |
| use of electrophoretic techniques and maldi-tof ms for rapid and reliable characterization of bacteria: analysis of intact cells, cell lysates, and "washed pellets". | in this study electrophoretic and mass spectrometric analysis of three types of bacterial sample (intact cells, cell lysates, and "washed pellets") were used to develop an effective procedure for the characterization of bacteria. the samples were prepared from specific bacterial strains. five strains representing different species of the family rhizobiaceae were selected as model microorganisms: rhizobium leguminosarum bv. trifolii, r. leguminosarum bv. viciae, r. galegae, r. loti, and sinorhizo ... | 2013 | 23388690 |
| characterization of root-nodule bacteria isolated from vicia faba and selection of plant growth promoting isolates. | a collection of 104 isolates from root-nodules of vicia faba was submitted to 16s rrna pcr-rflp typing. a representative sample was further submitted to sequence analysis of 16s rrna. isolates were assigned to 12 genera. all the nodulating isolates (45 %) were closely related to rhizobium leguminosarum usda2370(t) (99.34 %). the remaining isolates, including potential human pathogens, failed to nodulate their original host. they were checked for presence of symbiotic genes, p-solubilization, phy ... | 2013 | 23397108 |
| draft genome sequence of rhizobium mesoamericanum stm3625, a nitrogen-fixing symbiont of mimosa pudica isolated in french guiana (south america). | rhizobium mesoamericanum stm3625 is a mimosa pudica symbiont isolated in french guiana. this strain serves as a model bacterium for comparison of adaptation to mutualism (symbiotic traits, bacterial genetic programs for plant infection) between alpha and beta rhizobial symbionts of mimosa pudica. | 2013 | 23405314 |
| genome sequence of rhizobium lupini hpc(l) isolated from saline desert soil, kutch (gujarat). | the rhizobium lupini strain hpc(l) was isolated from saline desert soil. it grows on minimal media supplemented with caco(3) as a carbon source. it can also grow under both oligotrophic and heteroptrophic conditions. we report the annotated genome sequence of this strain in a 5.27-mb scaffold. | 2013 | 23405347 |
| a model for tetrapyrrole synthesis as the primary mechanism for plastid-to-nucleus signaling during chloroplast biogenesis. | chloroplast biogenesis involves the co-ordinated expression of the chloroplast and nuclear genomes, requiring information to be sent from the developing chloroplasts to the nucleus. this is achieved through retrograde signaling pathways and can be demonstrated experimentally using the photobleaching herbicide, norflurazon, which in seedlings results in chloroplast damage and the reduced expression of many photosynthesis-related, nuclear genes. genetic analysis of this pathway points to a major r ... | 2013 | 23407626 |
| queuosine biosynthesis is required for sinorhizobium meliloti-induced cytoskeletal modifications on hela cells and symbiosis with medicago truncatula. | rhizobia are symbiotic soil bacteria able to intracellularly colonize legume nodule cells and form nitrogen-fixing symbiosomes therein. how the plant cell cytoskeleton reorganizes in response to rhizobium colonization has remained poorly understood especially because of the lack of an in vitro infection assay. here, we report on the use of the heterologous hela cell model to experimentally tackle this question. we observed that the model rhizobium sinorhizobium meliloti, and other rhizobia as we ... | 2013 | 23409119 |
| the metadata coverage index (mci): a standardized metric for quantifying database metadata richness. | variability in the extent of the descriptions of data ('metadata') held in public repositories forces users to assess the quality of records individually, which rapidly becomes impractical. the scoring of records on the richness of their description provides a simple, objective proxy measure for quality that enables filtering that supports downstream analysis. pivotally, such descriptions should spur on improvements. here, we introduce such a measure - the 'metadata coverage index' (mci): the pe ... | 2012 | 23409217 |
| phenotype profiling of rhizobium leguminosarum bv. trifolii clover nodule isolates reveal their both versatile and specialized metabolic capabilities. | rhizobium leguminosarum bv. trifolii (rlt) are soil bacteria inducing nodules on clover, where they fix nitrogen. genome organization analyses of 22 rlt clover nodule isolates showed that they contained 3-6 plasmids and majority of them possessed large (>1 mb), chromid-like replicon with exception of four rlt strains. the biolog phenotypic profiling comprising utilization of c, n, p, and s sources and tolerance to osmolytes and ph revealed metabolic versatility of the rlt strains. statistical an ... | 2013 | 23417392 |
| plant-bacterium interactions analyzed by proteomics. | the evolution of the plant immune response has resulted in a highly effective defense system that is able to resist potential attack by microbial pathogens. the primary immune response is referred to as pathogen associated molecular pattern (pamp) triggered immunity and has evolved to recognize common features of microbial pathogens. in response to the delivery of pathogen effector proteins, plants acquired r proteins to fight against pathogen attack. r-dependent defense response is important in ... | 2013 | 23424014 |
| comparative genomics of the core and accessory genomes of 48 sinorhizobium strains comprising five genospecies. | the sinorhizobia are amongst the most well studied members of nitrogen-fixing root nodule bacteria and contribute substantial amounts of fixed nitrogen to the biosphere. while the alfalfa symbiont sinorhizobium meliloti rm 1021 was one of the first rhizobial strains to be completely sequenced, little information is available about the genomes of this large and diverse species group. | 2013 | 23425606 |
| phylogenetic analysis of erythritol catabolic loci within the rhizobiales and proteobacteria. | the ability to use erythritol as a sole carbon source is not universal among the rhizobiaceae. based on the relatedness to the catabolic genes in brucella it has been suggested that the eryabcd operon may have been horizontally transferred into rhizobium. during work characterizing a locus necessary for the transport and catabolism of erythritol, adonitol and l-arabitol in sinorhizobium meliloti, we became interested in the differences between the erythritol loci of s. meliloti and r. leguminosa ... | 2013 | 23432981 |
| structural analysis of succinoglycan oligosaccharides from sinorhizobium meliloti strains with different host compatibility phenotypes. | sinorhizobium meliloti nrg247 has a fix(+) phenotype on medicago truncatula a20 and is fix(-) on m. truncatula a17, and the phenotype is reversed with s. meliloti nrg185. as the succinoglycan was shown to impact host specificity, an analysis of the succinoglycan oligosaccharides produced by each strain was conducted. the symbiotically active succinoglycan trimeric oligosaccharides (stos) from the two s. meliloti strains were compared by chromatography and mass spectrometry, and the analysis of t ... | 2013 | 23457246 |
| 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 |
| 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 |
| discovery of functional toxin/antitoxin systems in bacteria by shotgun cloning. | toxin-antitoxin (ta) modules, composed of a toxic protein and a counteracting antitoxin, play important roles in bacterial physiology. we examined the experimental insertion of 1.5 million genes from 388 microbial genomes into an escherichia coli host using more than 8.5 million random clones. this revealed hundreds of genes (toxins) that could only be cloned when the neighboring gene (antitoxin) was present on the same clone. clustering of these genes revealed ta families widespread in bacteria ... | 2013 | 23478446 |
| 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 |
| rhizobium pisi sv. trifolii k3.22 harboring nod genes of the rhizobium leguminosarum sv. trifolii cluster. | the taxonomic status of the rhizobium sp. k3.22 clover nodule isolate was studied by multilocus sequence analysis (mlsa) of 16s rrna and six housekeeping chromosomal genes, as well as by a subsequent phylogenic analysis. the results revealed full congruence with the rhizobium pisi dsm 30132(t) core genes, thus supporting the same taxonomic position for both strains. however, the k3.22 plasmid symbiosis nod genes demonstrated high sequence similarity to rhizobium leguminosarum sv. trifolii, where ... | 2013 | 23507586 |
| elucidation of the 3-o-deacylase gene, pagl, required for the removal of primary β-hydroxy fatty acid from the lipid a in the nitrogen-fixing endosymbiont rhizobium etli ce3. | until now, the gene responsible for the 3-o-deacylation of lipid a among nitrogen-fixing endosymbionts has not been characterized. several gram-negative animal pathogens such as salmonella enterica, pseudomonas aeruginosa, and bordetella bronchiseptica contain an outer membrane 3-o-deacylase (pagl) that has been implicated in host immune evasion. the role of 3-o-deacylated lipid a among nitrogen-fixing endosymbionts, plant endophytes, and plant pathogens has not been studied. however, d'haeze et ... | 2013 | 23511636 |
| transcriptome analysis of the role of glnd/glnbk in nitrogen stress adaptation by sinorhizobium meliloti rm1021. | transcriptional changes in the nitrogen stress response (nsr) of wild type s. meliloti rm1021, and isogenic strains missing both pii proteins, glnb and glnk, or carrying a δglnd-sm2 mutation were analyzed using whole-genome microarrays. this approach allowed us to identify a number of new genes involved in the nsr and showed that the response of these bacteria to nitrogen stress overlaps with other stress responses, including induction of the fixk2 transcriptional activator and genes that are pa ... | 2013 | 23516427 |
| reciprocal regulation of the autophosphorylation of enzyme intr by glutamine and α-ketoglutarate in escherichia coli. | in addition to the phosphoenolpyruvate:sugar phosphotransferase system (sugar pts), most proteobacteria possess a paralogous system (nitrogen phosphotransferase system, pts(ntr)). the first proteins in both pathways are enzymes (enzyme i(sugar) and enzyme i(ntr)) that can be autophosphorylated by phosphoenolpyruvate. the most striking difference between enzyme i(sugar) and enzyme i(ntr) is the presence of a gaf domain at the n-terminus of enzyme i(ntr). since the pts(ntr) was identified in 1995, ... | 2013 | 23517463 |
| an omp gene enhances cell tolerance of cu(ii) in sinorhizobium meliloti ccnwsx0020. | the main aim of this work was to study molecular characterization of a dna fragment conferring resistance to cu(ii) in sinorhizobium meliloti ccnwsx0020. the strain ccnwsx0020, resistant to 1.4 mmol l(-1) cu(ii) in tryptone-yeast extract medium was isolated from medicago lupulina growing in mine tailings of fengxian county, china. the availability of the complete genome sequence of s. meliloti ccnwsx0020 provides an opportunity for investigating genes that play significant roles in cu(ii) resist ... | 2013 | 23526229 |
| rhizobial infection is associated with the development of peripheral vasculature in nodules of medicago truncatula. | nodulation in legumes involves the coordination of epidermal infection by rhizobia with cell divisions in the underlying cortex. during nodulation, rhizobia are entrapped within curled root hairs to form an infection pocket. transcellular tubes called infection threads then develop from the pocket and become colonized by rhizobia. the infection thread grows toward the developing nodule primordia and rhizobia are taken up into the nodule cells, where they eventually fix nitrogen. the epidermal an ... | 2013 | 23535942 |
| biochemical diversity of carboxyl esterases and lipases from lake arreo (spain): a metagenomic approach. | the esterases and lipases from the α/β hydrolase superfamily exhibit an enormous sequence diversity, fold plasticity, and activities. here, we present the comprehensive sequence and biochemical analyses of seven distinct esterases and lipases from the metagenome of lake arreo, an evaporite karstic lake in spain (42°46'n, 2°59'w; altitude, 655 m). together with oligonucleotide usage patterns and blastp analysis, our study of esterases/lipases mined from lake arreo suggests that its sediment conta ... | 2013 | 23542620 |
| functionally cloned pdrm from streptococcus pneumoniae encodes a na(+) coupled multidrug efflux pump. | multidrug efflux pumps play an important role as a self-defense system in bacteria. bacterial multidrug efflux pumps are classified into five families based on structure and coupling energy: resistance-nodulation-cell division (rnd), small multidrug resistance (smr), major facilitator (mf), atp binding cassette (abc), and multidrug and toxic compounds extrusion (mate). we cloned a gene encoding a mate-type multidrug efflux pump from streptococcus pneumoniae r6, and designated it pdrm. pdrm showe ... | 2013 | 23555691 |
| utilization of d-ribitol by lactobacillus casei bl23 requires a mannose-type phosphotransferase system and three catabolic enzymes. | lactobacillus casei strains 64h and bl23, but not atcc 334, are able to ferment d-ribitol (also called d-adonitol). however, a bl23-derived ptsi mutant lacking enzyme i of the phosphoenolpyruvate:carbohydrate phosphotransferase system (pts) was not able to utilize this pentitol, suggesting that strain bl23 transports and phosphorylates d-ribitol via a pts. we identified an 11-kb region in the genome sequence of l. casei strain bl23 (lcabl_29160 to lcabl_29270) which is absent from strain atcc 33 ... | 2013 | 23564164 |