| structure of 4-pyridoxolactonase from mesorhizobium loti. | 4-pyridoxolactonase from mesorhizobium loti catalyzes the zinc-dependent lactone-ring hydrolysis of 4-pyridoxolactone (4pal) to 4-pyridoxic acid (4pa) in vitamin b6 degradation pathway i. the crystal structures of 4-pyridoxolactonase and its complex with 5-pyridoxolactone (5pal; the competitive inhibitor) were determined. the overall structure was an αβ/βα sandwich fold, and two zinc ions were coordinated. this strongly suggested that the enzyme belongs to subclass b3 of the class b β-lactamases ... | 2014 | 24699732 |
| direct exchange of vitamin b12 is demonstrated by modelling the growth dynamics of algal-bacterial cocultures. | the growth dynamics of populations of interacting species in the aquatic environment is of great importance, both for understanding natural ecosystems and in efforts to cultivate these organisms for industrial purposes. here we consider a simple two-species system wherein the bacterium mesorhizobium loti supplies vitamin b12 (cobalamin) to the freshwater green alga lobomonas rostrata, which requires this organic micronutrient for growth. in return, the bacterium receives photosynthate from the a ... | 2014 | 24522262 |
| fixating on metals: new insights into the role of metals in nodulation and symbiotic nitrogen fixation. | symbiotic nitrogen fixation is one of the most promising and immediate alternatives to the overuse of polluting nitrogen fertilizers for improving plant nutrition. at the core of this process are a number of metalloproteins that catalyze and provide energy for the conversion of atmospheric nitrogen to ammonia, eliminate free radicals produced by this process, and create the microaerobic conditions required by these reactions. in legumes, metal cofactors are provided to endosymbiotic rhizobia wit ... | 2014 | 24592271 |
| a kcsa/mlok1 chimeric ion channel has lipid-dependent ligand-binding energetics. | cyclic nucleotide-modulated ion channels play crucial roles in signal transduction in eukaryotes. the molecular mechanism by which ligand binding leads to channel opening remains poorly understood, due in part to the lack of a robust method for preparing sufficient amounts of purified, stable protein required for structural and biochemical characterization. to overcome this limitation, we designed a stable, highly expressed chimeric ion channel consisting of the transmembrane domains of the well ... | 2014 | 24515111 |
| ligand-induced structural changes in the cyclic nucleotide-modulated potassium channel mlok1. | cyclic nucleotide-modulated ion channels are important for signal transduction and pacemaking in eukaryotes. the molecular determinants of ligand gating in these channels are still unknown, mainly because of a lack of direct structural information. here we report ligand-induced conformational changes in full-length mlok1, a cyclic nucleotide-modulated potassium channel from the bacterium mesorhizobium loti, analysed by electron crystallography and atomic force microscopy. upon camp binding, the ... | 2014 | 24469021 |
| epigenetic mechanisms and microbiota as a toolbox for plant phenotypic adjustment to environment. | the classic understanding of organisms focuses on genes as the main source of species evolution and diversification. the recent concept of genetic accommodation questions this gene centric view by emphasizing the importance of phenotypic plasticity on evolutionary trajectories. recent discoveries on epigenetics and symbiotic microbiota demonstrated their deep impact on plant survival, adaptation and evolution thus suggesting a novel comprehension of the plant phenotype. in addition, interplays b ... | 2015 | 26779191 |
| mesopelagic n2 fixation related to organic matter composition in the solomon and bismarck seas (southwest pacific). | dinitrogen (n2) fixation was investigated together with organic matter composition in the mesopelagic zone of the bismarck (transect 1) and solomon (transect 2) seas (southwest pacific). transparent exopolymer particles (tep) and the presence of compounds sharing molecular formulae with saturated fatty acids and sugars, as well as dissolved organic matter (dom) compounds containing nitrogen (n) and phosphorus (p) were higher on transect 1 than on transect 2, while oxygen concentrations showed an ... | 2015 | 26659074 |
| possible role of 1-aminocyclopropane-1-carboxylate (acc) deaminase activity of sinorhizobium sp. bl3 on symbiosis with mung bean and determinate nodule senescence. | sinorhizobium sp. bl3 forms symbiotic interactions with mung bean (vigna radiata) and contains lrpl-acds genes, which encode the 1-aminocyclopropane-1-carboxylate (acc) deaminase enzyme that cleaves acc, a precursor of plant ethylene synthesis. since ethylene interferes with nodule formation in some legumes and plays a role in senescence in plant cells, bl3-enhancing acc deaminase activity (bl3(+)) and defective mutant (bl3(-)) strains were constructed in order to investigate the effects of this ... | 2015 | 26657304 |
| the type iii secretion system (t3ss) is a determinant for rice-endophyte colonization by non-photosynthetic bradyrhizobium. | plant associations by bradyrhizobia have been detected not only in leguminous plants, but also in non-leguminous species including rice. bradyrhizobium sp. sutn9-2 was isolated from aeschynomene americana l., which is a leguminous weed found in the rice fields of thailand. this strain promoted the highest total rice (oryza sativa l. cultivar pathum thani 1) dry weight among the endophytic bradyrhizobial strains tested, and was, thus, employed for the further characterization of rice-bradyrhizobi ... | 2015 | 26582551 |
| draft genome sequences of facultative methylotrophs, gemmobacter sp. strain lw1 and mesorhizobium sp. strain 1m-11, isolated from movile cave, romania. | facultative methylotrophs belonging to the genera gemmobacter and mesorhizobium were isolated from microbial mat and cave water samples obtained from the movile cave ecosystem. both bacteria can utilize methylated amines as their sole carbon and nitrogen source. here, we report the draft genome sequences of gemmobacter sp. strain lw1 and mesorhizobium sp. strain im1. | 2015 | 26586870 |
| silencing quorum sensing and ice mobility through antiactivation and ribosomal frameshifting. | mobile genetic elements run an evolutionary gauntlet to maintain their mobility in the face of selection against their selfish dissemination but, paradoxically, they can accelerate the adaptability of bacteria through the gene-transfer events that they facilitate. these temporally conflicting evolutionary forces have shaped exquisite regulation systems that silence mobility and maximize the competitive fitness of the host bacterium, but maintain the ability of the element to deliver itself to a ... | 2015 | 26942047 |
| ensifer-mediated transformation: an efficient non-agrobacterium protocol for the genetic modification of rice. | while agrobacterium-mediated transformation (amt) remains the most widely used technique for gene transfer in plants, interest exists for the use of non-agrobacterium gene delivery systems due to freedom-to-operate issues that remain with amt across several jurisdictions. in addition, the plant pathogenic mode of action of agrobacterium tumefaciens significantly increases the costs to passage engineered cultivars through the regulatory process. ensifer adhaerens (ov14) is a soil-related bacteriu ... | 2015 | 26543735 |
| phod alkaline phosphatase gene diversity in soil. | phosphatase enzymes are responsible for much of the recycling of organic phosphorus in soils. the phod alkaline phosphatase takes part in this process by hydrolyzing a range of organic phosphoesters. we analyzed the taxonomic and environmental distribution of phod genes using whole-genome and metagenome databases. phod alkaline phosphatase was found to be spread across 20 bacterial phyla and was ubiquitous in the environment, with the greatest abundance in soil. to study the great diversity of p ... | 2015 | 26253682 |
| colonization of root cells and plant growth promotion by piriformospora indica occurs independently of plant common symbiosis genes. | arbuscular mycorrhiza (am) fungi (glomeromycota) form symbiosis with and deliver nutrients via the roots of most angiosperms. am fungal hyphae are taken up by living root epidermal cells, a program which relies on a set of plant common symbiosis genes (csgs). plant root epidermal cells are also infected by the plant growth-promoting fungus piriformospora indica (basidiomycota), raising the question whether this interaction relies on the am-related csgs. here we show that intracellular colonizati ... | 2015 | 26441999 |
| two-dimensional crystallization procedure, from protein expression to sample preparation. | membrane proteins play important roles for living cells. structural studies of membrane proteins provide deeper understanding of their mechanisms and further aid in drug design. as compared to other methods, electron microscopy is uniquely suitable for analysis of a broad range of specimens, from small proteins to large complexes. of various electron microscopic methods, electron crystallography is particularly well-suited to study membrane proteins which are reconstituted into two-dimensional c ... | 2015 | 26413539 |
| nitrogen-fixing nodules are an important source of reduced sulfur, which triggers global changes in sulfur metabolism in lotus japonicus. | we combined transcriptomic and biochemical approaches to study rhizobial and plant sulfur (s) metabolism in nitrogen (n) fixing nodules (fix(+)) of lotus japonicus, as well as the link of s-metabolism to symbiotic nitrogen fixation and the effect of nodules on whole-plant s-partitioning and metabolism. our data reveal that n-fixing nodules are thiol-rich organs. their high adenosine 5'-phosphosulfate reductase activity and strong (35)s-flux into cysteine and its metabolites, in combination with ... | 2015 | 26296963 |
| high-quality draft genome sequence of the lotus spp. microsymbiont mesorhizobium loti strain cj3sym. | mesorhizobium loti strain cj3sym was isolated in 1998 following transfer of the integrative and conjugative element icemlsym(r7a), also known as the r7a symbiosis island, in a laboratory mating from the donor m. loti strain r7a to a nonsymbiotic recipient mesorhizobium strain cj3. strain cj3 was originally isolated from a field site in the rocklands range in new zealand in 1994. cj3sym is an aerobic, gram-negative, non-spore-forming rod. this report reveals the genome of m. loti strain cj3sym cu ... | 2015 | 26380641 |
| hormonal control of lateral root and nodule development in legumes. | many plants can establish symbioses with nitrogen-fixing bacteria, some of which lead to nodulation, including legumes. indeed, in the rhizobium/legume symbiosis, new root organs, called nodules, are formed by the plant in order to host the rhizobia in protective conditions, optimized for nitrogen fixation. in this way, these plants can benefit from the reduction of atmospheric dinitrogen into ammonia by the hosted bacteria, and in exchange the plant provides the rhizobia with a carbon source. s ... | 2015 | 27135340 |
| involvement of rop6 and clathrin in nodulation factor signaling. | the symbiotic association between the legume lotus japonicus and the nitrogen-fixing bacterium mesorhizobium loti results in the formation of root nodules. this process begins with the recognition of the rhizobial nodulation factor (nf) by the nf receptors (nfr) at the cell surface of the host roots. the downstream signaling cascades after nfr recognition have not been fully characterized. we recently identified a clathrin heavy chain 1 (chc1) from l. japonicus as a potential target of the nf si ... | 2015 | 26251877 |
| aquaporin-based biomimetic polymeric membranes: approaches and challenges. | in recent years, aquaporin biomimetic membranes (abms) for water separation have gained considerable interest. although the first abms are commercially available, there are still many challenges associated with further abm development. here, we discuss the interplay of the main components of abms: aquaporin proteins (aqps), block copolymers for aqp reconstitution, and polymer-based supporting structures. first, we briefly cover challenges and review recent developments in understanding the inter ... | 2015 | 26264033 |
| shoot har1 mediates nitrate inhibition of nodulation in lotus japonicus. | nitrate is a major environmental factor in the inhibition of nodulation. in a model legume lotus japonicus, a clv1-like receptor kinase, har1, mediates nitrate inhibition and autoregulation of nodulation. autoregulation of nodulation involves root-to-shoot-to-root long-distance communication, and har1 functions in shoots. however, it remains elusive where har1 functions in the nitrate inhibition of nodulation. we performed grafting experiments with the har1 mutant under various nitrate condition ... | 2015 | 26039467 |
| a census of nuclear cyanobacterial recruits in the plant kingdom. | the plastids and mitochondria of the eukaryotic cell are of endosymbiotic origin. these events occurred ~2 billion years ago and produced significant changes in the genomes of the host and the endosymbiont. previous studies demonstrated that the invasion of land affected plastids and mitochondria differently and that the paths of mitochondrial integration differed between animals and plants. other studies examined the reasons why a set of proteins remained encoded in the organelles and were not ... | 2015 | 25794152 |
| ribosomal frameshifting and dual-target antiactivation restrict quorum-sensing-activated transfer of a mobile genetic element. | symbiosis islands are integrative and conjugative mobile genetic elements that convert nonsymbiotic rhizobia into nitrogen-fixing symbionts of leguminous plants. excision of the mesorhizobium loti symbiosis island icemlsym(r7a) is indirectly activated by quorum sensing through trar-dependent activation of the excisionase gene rdfs. here we show that a +1 programmed ribosomal frameshift (prf) fuses the coding sequences of two trar-activated genes, msi172 and msi171, producing an activator of rdfs ... | 2015 | 25787256 |
| structural and enzymatic characterization of the choline kinase lica from streptococcus pneumoniae. | lica plays a key role in the cell-wall phosphorylcholine biosynthesis of streptococcus pneumonia. here we determined the crystal structures of apo-form lica at 1.94 å and two complex forms lica-choline and lica-amp-mes, at 2.01 and 1.45 å resolution, respectively. the overall structure adopts a canonical protein kinase-like fold, with the active site located in the crevice of the n- and c-terminal domains. the three structures present distinct poses of the active site, which undergoes an open-cl ... | 2015 | 25781969 |
| function of glutathione peroxidases in legume root nodules. | glutathione peroxidases (gpxs) are antioxidant enzymes not studied so far in legume nodules, despite the fact that reactive oxygen species are produced at different steps of the symbiosis. the function of two gpxs that are highly expressed in nodules of the model legume lotus japonicus was examined. gene expression analysis, enzymatic and nitrosylation assays, yeast cell complementation, in situ mrna hybridization, immunoelectron microscopy, and ljgpx-green fluorescent protein (gfp) fusions were ... | 2015 | 25740929 |
| bacterial genospecies that are not ecologically coherent: population genomics of rhizobium leguminosarum. | biological species may remain distinct because of genetic isolation or ecological adaptation, but these two aspects do not always coincide. to establish the nature of the species boundary within a local bacterial population, we characterized a sympatric population of the bacterium rhizobium leguminosarum by genomic sequencing of 72 isolates. although all strains have 16s rrna typical of r. leguminosarum, they fall into five genospecies by the criterion of average nucleotide identity (ani). many ... | 2015 | 25589577 |
| structural and catalytic properties of s1 nuclease from aspergillus oryzae responsible for substrate recognition, cleavage, non-specificity, and inhibition. | the single-strand-specific s1 nuclease from aspergillus oryzae is an archetypal enzyme of the s1-p1 family of nucleases with a widespread use for biochemical analyses of nucleic acids. we present the first x-ray structure of this nuclease along with a thorough analysis of the reaction and inhibition mechanisms and of its properties responsible for identification and binding of ligands. seven structures of s1 nuclease, six of which are complexes with products and inhibitors, and characterization ... | 2016 | 28036383 |
| root nodule symbiosis in lotus japonicus drives the establishment of distinctive rhizosphere, root, and nodule bacterial communities. | lotus japonicus has been used for decades as a model legume to study the establishment of binary symbiotic relationships with nitrogen-fixing rhizobia that trigger root nodule organogenesis for bacterial accommodation. using community profiling of 16s rrna gene amplicons, we reveal that in lotus, distinctive nodule- and root-inhabiting communities are established by parallel, rather than consecutive, selection of bacteria from the rhizosphere and root compartments. comparative analyses of wild-t ... | 2016 | 27864511 |
| reclassification of the taxonomic status of semia3007 isolated in mexico b-11a mex as rhizobium leguminosarum bv. viceae by bioinformatic tools. | evidence based on genomic sequences is extremely important to confirm the phylogenetic relationships within the rhizobium group. semia3007 was analyzed within the mesorhizobium groups to define the underlying causes of taxonomic identification. we previously used biochemical tests and phenotypic taxonomic methods to identify bacteria, which can lead to erroneous classification. an improved understanding of bacterial strains such as the mesorhizobium genus would increase our knowledge of classifi ... | 2016 | 27814683 |
| surface properties of wild-type rhizobium leguminosarum bv. trifolii strain 24.2 and its derivatives with different extracellular polysaccharide content. | rhizobium leguminosarum bv. trifolii is a soil bacterium able to establish symbiosis with agriculturally important legumes, i.e., clover plants (trifolium spp.). cell surface properties of rhizobia play an essential role in their interaction with both biotic and abiotic surfaces. physicochemical properties of bacterial cells are underpinned by the chemical composition of their envelope surrounding the cells, and depend on various environmental conditions. in this study, we performed a comprehens ... | 2016 | 27760230 |
| assembly and transfer of tripartite integrative and conjugative genetic elements. | integrative and conjugative elements (ices) are ubiquitous mobile genetic elements present as "genomic islands" within bacterial chromosomes. symbiosis islands are ices that convert nonsymbiotic mesorhizobia into symbionts of legumes. here we report the discovery of symbiosis ices that exist as three separate chromosomal regions when integrated in their hosts, but through recombination assemble as a single circular ice for conjugative transfer. whole-genome comparisons revealed exconjugants deri ... | 2016 | 27733511 |
| whole-genome sequence of the nitrogen-fixing symbiotic rhizobium mesorhizobium loti strain tono. | mesorhizobium loti is the nitrogen-fixing microsymbiont for legumes of the genus lotus here, we report the whole-genome sequence of a mesorhizobium loti strain, tono, which is used as a symbiont for the model legume lotus japonicus the whole-genome sequence of the strain tono will be a solid platform for comparative genomics analyses and for the identification of genes responsible for the symbiotic properties of mesorhizobium species. | 2016 | 27795235 |
| real-time visualization of conformational changes within single mlok1 cyclic nucleotide-modulated channels. | eukaryotic cyclic nucleotide-modulated (cnm) ion channels perform various physiological roles by opening in response to cyclic nucleotides binding to a specialized cyclic nucleotide-binding domain. despite progress in structure-function analysis, the conformational rearrangements underlying the gating of these channels are still unknown. here, we image ligand-induced conformational changes in single cnm channels from mesorhizobium loti (mlok1) in real-time, using high-speed atomic force microsco ... | 2016 | 27647260 |
| efficient inactivation of symbiotic nitrogen fixation related genes in lotus japonicus using crispr-cas9. | the targeted genome editing technique, crispr/cas9 system, has been widely used to modify genes of interest in a predictable and precise manner. in this study, we describe the crispr/cas9-mediated efficient editing of representative snf (symbiotic nitrogen fixation) related genes in the model legume lotus japonicus via agrobacterium-mediated stable or hairy root transformation. we first predicted nine endogenous u6 genes in lotus and then demonstrated the efficacy of the lju6-1 gene promoter in ... | 2016 | 27630657 |
| overexpression of the starch phosphorylase-like gene (pho3) in lotus japonicus has a profound effect on the growth of plants and reduction of transitory starch accumulation. | two isoforms of starch phosphorylase (pho; ec 2.4.1.1), plastidic pho1 and cytosolic pho2, have been found in all plants studied to date. another starch phosphorylase-like gene, pho3, which is an ortholog of chlamydomonas phob, has been detected in some plant lineages. in this study, we identified three pho isoform (ljpho) genes in the lotus japonicus genome. expression of the ljpho3 gene was observed in all tissues tested in l. japonicus, and the ljpho3 protein was located in the chloroplast. o ... | 2016 | 27630651 |
| metagenomic analysis revealed methylamine and ureide utilization of soybean-associated methylobacterium. | methylobacterium inhabits the phyllosphere of a large number of plants. we herein report the results of comparative metagenome analyses on methylobacterial communities of soybean plants grown in an experimental field in tohoku university (kashimadai, miyagi, japan). methylobacterium was identified as the most dominant genus (33%) among bacteria inhabiting soybean stems. we classified plant-derived methylobacterium species into groups i, ii, and iii based on 16s rrna gene sequences, and found tha ... | 2016 | 27431374 |
| growth rate of and gene expression in bradyrhizobium diazoefficiens usda110 due to a mutation in blr7984, a tetr family transcriptional regulator gene. | previous transcriptome analyses have suggested that a gene cluster including a transcriptional regulator (blr7984) of the tetracycline repressor family was markedly down-regulated in symbiosis. since blr7984 is annotated to be the transcriptional repressor, we hypothesized that it is involved in the repression of genes in the genomic cluster including blr7984 in symbiotic bacteroids. in order to examine the function and involvement of the blr7984 gene in differentiation into bacteroids, we compa ... | 2016 | 27383683 |
| how mutualisms arise in phytoplankton communities: building eco-evolutionary principles for aquatic microbes. | extensive sampling and metagenomics analyses of plankton communities across all aquatic environments are beginning to provide insights into the ecology of microbial communities. in particular, the importance of metabolic exchanges that provide a foundation for ecological interactions between microorganisms has emerged as a key factor in forging such communities. here we show how both studies of environmental samples and physiological experimentation in the laboratory with defined microbial co-cu ... | 2016 | 27282316 |
| complete genome sequence of mesorhizobium ciceri bv. biserrulae strain wsm1284, an efficient nitrogen-fixing microsymbiont of the pasture legume biserrula pelecinus. | we report the complete genome sequence of mesorhizobium ciceri bv. biserrulae strain wsm1284, a nitrogen-fixing microsymbiont of the pasture legume biserrula pelecinus the genome consists of 6.88 mb distributed between a single chromosome (6.33 mb) and a single plasmid (0.55 mb). | 2016 | 27284134 |
| legume nadph oxidases have crucial roles at different stages of nodulation. | plant nadph oxidases, formerly known as respiratory burst oxidase homologues (rbohs), are plasma membrane enzymes dedicated to reactive oxygen species (ros) production. these oxidases are implicated in a wide variety of processes, ranging from tissue and organ growth and development to signaling pathways in response to abiotic and biotic stimuli. research on the roles of rbohs in the plant's response to biotic stresses has mainly focused on plant-pathogen interactions; nonetheless, recent findin ... | 2016 | 27213330 |
| use of transcriptomics and co-expression networks to analyze the interconnections between nitrogen assimilation and photorespiratory metabolism. | nitrogen is one of the most important nutrients for plants and, in natural soils, its availability is often a major limiting factor for plant growth. here we examine the effect of different forms of nitrogen nutrition and of photorespiration on gene expression in the model legume lotus japonicus with the aim of identifying regulatory candidate genes co-ordinating primary nitrogen assimilation and photorespiration. the transcriptomic changes produced by the use of different nitrogen sources in le ... | 2016 | 27117340 |
| cyanobacteria and eukaryotic algae use different chemical variants of vitamin b12. | eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor b12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. there are several ... | 2016 | 27040778 |
| integrating dna methylation and gene expression data in the development of the soybean-bradyrhizobium n2-fixing symbiosis. | very little is known about the role of epigenetics in the differentiation of a bacterium from the free-living to the symbiotic state. here genome-wide analysis of dna methylation changes between these states is described using the model of symbiosis between soybean and its root nodule-forming, nitrogen-fixing symbiont, bradyrhizobium diazoefficiens. pacbio resequencing of the b. diazoefficiens genome from both states revealed 43,061 sites recognized by five motifs with the potential to be methyl ... | 2016 | 27148207 |
| a comparative proteomics study of a synovial cell line stimulated with tnf-α. | to elucidate the pathogenesis of rheumatoid arthritis (ra), we used proteomic analysis to determine the protein profile in a synovial cell line, mh7a, established from patients with ra. proteins were extracted from mh7a cells that were or were not stimulated with tumor necrosis factor-α (tnf-α), and then analyzed on a liquid chromatography/mass spectrometry system equipped with a unique long monolithic silica capillary. on the basis of the results of this proteomic analysis, we identified 2650 p ... | 2016 | 27419047 |
| a novel biosensor to study camp dynamics in cilia and flagella. | the cellular messenger camp regulates multiple cellular functions, including signaling in cilia and flagella. the camp dynamics in these subcellular compartments are ill-defined. we introduce a novel fret-based camp biosensor with nanomolar sensitivity that is out of reach for other sensors. to measure camp dynamics in the sperm flagellum, we generated transgenic mice and reveal that the hitherto methods determining total camp levels do not reflect changes in free camp levels. moreover, camp dyn ... | 2016 | 27003291 |
| a functional bacterium-to-plant dna transfer machinery of rhizobium etli. | different strains and species of the soil phytopathogen agrobacterium possess the ability to transfer and integrate a segment of dna (t-dna) into the genome of their eukaryotic hosts, which is mainly mediated by a set of virulence (vir) genes located on the bacterial ti-plasmid that also contains the t-dna. to date, agrobacterium is considered to be unique in its capacity to mediate genetic transformation of eukaryotes. however, close homologs of the vir genes are encoded by the p42a plasmid of ... | 2016 | 26968003 |
| preservation of ancestral cretaceous microflora recovered from a hypersaline oil reservoir. | microbiology of a hypersaline oil reservoir located in central africa was investigated with molecular and culture methods applied to preserved core samples. here we show that the community structure was partially acquired during sedimentation, as many prokaryotic 16s rrna gene sequences retrieved from the extracted dna are phylogenetically related to actual archaea inhabiting surface evaporitic environments, similar to the cretaceous sediment paleoenvironment. results are discussed in term of mi ... | 2016 | 26965360 |
| plant er geometry and dynamics: biophysical and cytoskeletal control during growth and biotic response. | the endoplasmic reticulum (er) is an intricate and dynamic network of membrane tubules and cisternae. in plant cells, the er 'web' pervades the cortex and endoplasm and is continuous with adjacent cells as it passes through plasmodesmata. it is therefore the largest membranous organelle in plant cells. it performs essential functions including protein and lipid synthesis, and its morphology and movement are linked to cellular function. an emerging trend is that organelles can no longer be seen a ... | 2016 | 26862751 |
| plant er geometry and dynamics: biophysical and cytoskeletal control during growth and biotic response. | the endoplasmic reticulum (er) is an intricate and dynamic network of membrane tubules and cisternae. in plant cells, the er 'web' pervades the cortex and endoplasm and is continuous with adjacent cells as it passes through plasmodesmata. it is therefore the largest membranous organelle in plant cells. it performs essential functions including protein and lipid synthesis, and its morphology and movement are linked to cellular function. an emerging trend is that organelles can no longer be seen a ... | 2016 | 26862751 |
| atkc1 and cipk23 synergistically modulate akt1-mediated low-potassium stress responses in arabidopsis. | in arabidopsis (arabidopsis thaliana), the shaker k(+) channel akt1 conducts k(+) uptake in root cells, and its activity is regulated by cbl1/9-cipk23 complexes as well as by the atkc1 channel subunit. cipk23 and atkc1 are both involved in the akt1-mediated low-k(+) (lk) response; however, the relationship between them remains unclear. in this study, we screened suppressors of low-k(+) sensitive [lks1 (cipk23)] and isolated the suppressor of lks1 (sls1) mutant, which suppressed the leaf chlorosi ... | 2016 | 26829980 |
| vasohibins: new transglutaminase-like cysteine proteases possessing a non-canonical cys-his-ser catalytic triad. | vasohibin-1 and vasohibin-2 regulate angiogenesis, tumour growth and metastasis. their molecular functions, however, were previously unknown, in large part owing to their perceived lack of homology to proteins of known structure and function. to identify their functional amino acids and domains, their molecular activity and their evolutionary history, we undertook an in-depth analysis of vasohibin sequences. we find that vasohibin proteins are previously undetected members of the transglutaminas ... | 2016 | 26794318 |
| plant pathogens affecting the establishment of plant-symbiont interaction. | | 2016 | 26834779 |
| genome sequence of the symbiotic type strain rhizobium tibeticum ccbau85039t. | rhizobium tibeticum was originally isolated from root nodules of trigonella archiducis-nicolai grown in tibet, china. this species is also able to nodulate medicago sativa and phaseolus vulgaris the whole-genome sequence of the type strain, r. tibeticum ccbau85039(t), is reported in this study. | 2017 | 28126941 |
| gipsy: genomic island prediction software. | bacteria are highly diverse organisms that are able to adapt to a broad range of environments and hosts due to their high genomic plasticity. horizontal gene transfer plays a pivotal role in this genome plasticity and in evolution by leaps through the incorporation of large blocks of genome sequences, ordinarily known as genomic islands (geis). geis may harbor genes encoding virulence, metabolism, antibiotic resistance and symbiosis-related functions, namely pathogenicity islands (pais), metabol ... | 2016 | 26376473 |
| structural insight into l-ribulose 3-epimerase from mesorhizobium loti. | l-ribulose 3-epimerase (l-re) from mesorhizobium loti has been identified as the first ketose 3-epimerase that shows the highest observed activity towards ketopentoses. in the present study, the crystal structure of the enzyme was determined to 2.7 å resolution. the asymmetric unit contained two homotetramers with the monomer folded into an (α/β)8-barrel carrying four additional short α-helices. the overall structure of m. loti l-re showed significant similarity to the structures of ketose 3-epi ... | 2013 | 24311575 |
| insight into cofactor recognition in arylamine n-acetyltransferase enzymes: structure of mesorhizobium loti arylamine n-acetyltransferase in complex with coenzyme a. | arylamine n-acetyltransferases (nats) are xenobiotic metabolizing enzymes that catalyze the acetyl-coa-dependent acetylation of arylamines. to better understand the mode of binding of the cofactor by this family of enzymes, the structure of mesorhizobium loti nat1 [(rhilo)nat1] was determined in complex with coa. the f42w mutant of (rhilo)nat1 was used as it is well expressed in escherichia coli and displays enzymatic properties similar to those of the wild type. the apo and holo structures of ( ... | 2015 | 25664736 |
| genomic analysis of cyclic-di-gmp-related genes in rhizobial type strains and functional analysis in rhizobium etli. | rhizobia are soil bacteria that can fix nitrogen in symbiosis with leguminous plants or exist free living in the rhizosphere. crucial to their complex lifestyle is the ability to sense and respond to diverse environmental stimuli, requiring elaborate signaling pathways. in the majority of bacteria, the nucleotide-based second messenger cyclic diguanosine monophosphate (c-di-gmp) is involved in signal transduction. surprisingly, little is known about the importance of c-di-gmp signaling in rhizob ... | 2014 | 24728599 |
| rhizobium leguminosarum symbiovar trifolii, ensifer numidicus and mesorhizobium amorphae symbiovar ciceri (or mesorhizobium loti) are new endosymbiotic bacteria of lens culinaris medik. | a total of 142 rhizobial bacteria were isolated from root nodules of lens culinaris medik endemic to tunisia and they belonged to the species rhizobium leguminosarum, and for the first time to ensifer and mesorhizobium, genera never previously described as microsymbionts of lentil. phenotypically, our results indicate that l. culinaris medik strains showed heterogenic responses to the different phenotypic features and they effectively nodulated their original host. based on the concatenation of ... | 2016 | 27267929 |
| development of a multi-enzymatic cascade reaction for the synthesis of trans-3-hydroxy-l-proline from l-arginine. | naturally occurring l-hydroxyproline in its four regio- and stereoisomeric forms has been explored as a possible precursor for pharmaceutical agents, yet the selective synthesis of trans-3-hydroxy-l-proline has not been achieved. our aim was to develop a novel biocatalytic asymmetric method for the synthesis of trans-3-hydroxy-l-proline. so far, we focused on the rhizobial arginine catabolic pathway: arginase and ornithine cyclodeaminase are involved in l-arginine degradation to l-proline via l- ... | 2016 | 26411456 |
| mesorhizobium waimense sp. nov. isolated from sophora longicarinata root nodules and mesorhizobium cantuariense sp. nov. isolated from sophora microphylla root nodules. | in total 14 strains of gram-stain-negative, rod-shaped bacteria were isolated from sophora longicarinata and sophora microphylla root nodules and authenticated as rhizobia on these hosts. based on the 16s rrna gene phylogeny, they were shown to belong to the genus mesorhizobium, and the strains from s. longicarinata were most closely related to mesorhizobium amorphae accc 19665t (99.8–99.9 %), mesorhizobium huakuii iam 14158t (99.8–99.9 %), mesorhizobium loti usda 3471t (99.5–99.9 %) and mesorhi ... | 2015 | 26296780 |
| mesorhizobium sangaii sp. nov., isolated from the root nodules of astragalus luteolus and astragalus ernestii. | our previous published data indicated that the two rhizobial strains scau7(t) and scau27, which were isolated from the root nodules of astragalus luteolus and astragalus ernestii respectively, in sichuan province, china, might be novel species of the genus mesorhizobium. their exact taxonomic position was determined in the present study by using polyphasic approaches. comparative analysis of nearly full-length 16s rrna gene sequences showed that these strains belonged to the genus mesorhizobium, ... | 2013 | 23315406 |
| mesorhizobium qingshengii sp. nov., isolated from effective nodules of astragalus sinicus. | in a study on the diversity of rhizobia isolated from root nodules of astragalus sinicus, five strains showed identical 16s rrna gene sequences. they were related most closely to the type strains of mesorhizobium loti, mesorhizobium shangrilense, mesorhizobium ciceri and mesorhizobium australicum, with sequence similarities of 99.6-99.8%. a polyphasic approach, including 16s-23s intergenic spacer (igs) rflp, comparative sequence analysis of 16s rrna, atpd, glnii and reca genes, dna-dna hybridiza ... | 2013 | 23041644 |
| revision of the taxonomic status of type strains of mesorhizobium loti and reclassification of strain usda 3471t as the type strain of mesorhizobiumerdmanii sp. nov. and atcc 33669t as the type strain of mesorhizobiumjarvisii sp. nov. | the species mesorhizobim loti was isolated from nodules of lotus corniculatus and its type strain deposited in several collections. some of these type strains, such as those deposited in the usda and atcc collections before 1990, are not coincident with the original strain, nzp 2213t, deposited in the nzp culture collection. the analysis of the 16s rrna gene showed that strains usda 3471t and atcc 33669t formed independent branches from that occupied by mesorhizobium loti nzp 2213t and related t ... | 2015 | 25736411 |
| local signalling pathways regulate the arabidopsis root developmental response to mesorhizobium loti inoculation. | | 2017 | 28199673 |
| iron-induced nitric oxide leads to an increase in the expression of ferritin during the senescence of lotus japonicus nodules. | iron is an essential nutrient for legume-rhizobium symbiosis and accumulates abundantly in the nodules. however, the concentration of free iron in the cells is strictly controlled to avoid toxicity. it is known that ferritin accumulates in the cells as an iron storage protein. during nodule senescence, the expression of the ferritin gene, ljfer1, was induced in lotus japonicus. we investigated a signal transduction pathway leading to the increase of ljfer1 in the nodule. the ljfer1 promoter of l ... | 2017 | 27889519 |
| sinorhizobium fredii hh103 invades lotus burttii by crack entry in a nod factor-and surface polysaccharide-dependent manner. | sinorhizobium fredii hh103-rif(r), a broad host range rhizobial strain, induces nitrogen-fixing nodules in lotus burttii but ineffective nodules in l. japonicus. confocal microscopy studies showed that mesorhizobium loti maff303099 and s. fredii hh103-rif(r) invade l. burttii roots through infection threads or epidermal cracks, respectively. infection threads in root hairs were not observed in l. burttii plants inoculated with s. fredii hh103-rif(r). a s. fredii hh103-rif(r) noda mutant failed t ... | 2016 | 27827003 |
| blue light perception by both roots and rhizobia inhibits nodule formation in lotus japonicus. | in many legumes, roots that are exposed to light do not form nodules. here, we report that blue light inhibits nodulation in lotus japonicus roots inoculated with mesorhizobium loti. using rna interference, we suppressed the expression of the phototropin and cryptochrome genes in l. japonicus hairy roots. under blue light, plants transformed with an empty vector did not develop nodules, whereas plants exhibiting suppressed expression of cry1 and cry2 genes formed nodules. we also measured rhizob ... | 2016 | 27611874 |
| rop6 is involved in root hair deformation induced by nod factors in lotus japonicus. | roots of leguminous plants perceive nod factor signals, and then root hair deformation responses such as swelling and curling are activated. however, very little is known about the molecular mechanisms of such root hair deformation. we have previously shown that ljrop6, a member of the rho family of small gtpases, was identified as an nfr5 (nod factor receptor 5)-interacting protein and participated in symbiotic nodulation in lotus japonicus. in this study, we identified ten ljrop gtpases includ ... | 2016 | 27592173 |
| the transcriptional factor ttsi is involved in a negative regulation of swimming motility in mesorhizobium loti maff303099. | mesorhizobium loti maff303099 has a functional type iii secretion system (t3ss) that is involved in the determination of competitiveness for legume nodulation. here we demonstrate that the transcriptional factor ttsi, which positively regulates t3ss genes expression, is involved in a negative regulation of m. loti swimming motility in soft-agar. conditions that induce t3ss expression affect flagella production. the same conditions also affect promoter activity of m. loti visn gene, a homolog to ... | 2016 | 27664056 |
| role of the tyr270 residue in 2-methyl-3-hydroxypyridine-5-carboxylic acid oxygenase from mesorhizobium loti. | the flavoenzyme 2-methyl-3-hydroxypyridine-5-carboxylic acid oxygenase (mhpco) catalyzes the cleavage of the pyridine ring of 2-methyl-3-hydroxypyridine-5-carboxylic acid (mhpc) in the presence of nadh, molecular oxygen, and water. mhpco also catalyzes the nadh oxidation reaction uncoupled with ring opening in the absence of mhpc (the basal activity). the enzyme shows activity toward not only mhpc but also 5-hydroxynicotinic acid (5hn) and 5-pyridoxic acid (5pa). the reaction rate toward 5pa is ... | 2017 | 27568368 |
| reclassification of strains maff 303099t and r7a into mesorhizobiumjaponicum sp. nov. | in this work we revise the taxonomic status of the lotus-nodulating strains maff 303099t and r7a isolated in japan and new zealand, respectively. their 16s rrna gene sequences are identical and show 98.0, 99.7, 99.8 and 99.9 % similarity values with respect to mesorhizobium loti nzp 2213t, m. jarvisii atcc 33669t, m. huakuii usda 4779t (=ccbau 2609t) and m. erdmanii usda 3471t, respectively. the analysis of reca and glnii gene sequeces showed that m. jarvisii atcc 33669t and m. huakuii usda 4779 ... | 2016 | 27565417 |
| structures of exopolysaccharides involved in receptor-mediated perception of mesorhizobium loti by lotus japonicus. | in the symbiosis formed between mesorhizobium loti strain r7a and lotus japonicus gifu, rhizobial exopolysaccharide (eps) plays an important role in infection thread formation. mutants of strain r7a affected in early exopolysaccharide biosynthetic steps form nitrogen-fixing nodules on l. japonicus gifu after a delay, whereas mutants affected in mid or late biosynthetic steps induce uninfected nodule primordia. recently, it was shown that a plant receptor-like kinase, epr3, binds low molecular ma ... | 2016 | 27502279 |
| global transcriptional response to salt shock of the plant microsymbiont mesorhizobium loti maff303099. | soil salinity affects rhizobia both as free-living bacteria and in symbiosis with the host. the aim of this study was to examine the transcriptional response of the lotus microsymbiont mesorhizobium loti maff303099 to salt shock. changes in the transcriptome of bacterial cells subjected to a salt shock of 10% nacl for 30 min were analyzed. from a total of 7231 protein-coding genes, 385 were found to be differentially expressed upon salt shock, among which 272 were overexpressed. although a large ... | 2017 | 27481227 |
| gene expression and localization of a β-1,3-glucanase of lotus japonicus. | phytohormone abscisic acid (aba) inhibits root nodule formation of leguminous plants. ljglu1, a β-1,3-glucanase gene of lotus japonicus, has been identified as an aba responsive gene. rna interference of ljglu1 increased nodule number. this suggests that ljglu1 is involved in the regulation of nodule formation. host legumes control nodule number by autoregulation of nodulation (aon), in which the presence of existing root nodules inhibits further nodulation. for further characterization of ljglu ... | 2016 | 26951113 |
| quantitative time-course proteome analysis of mesorhizobium loti during nodule maturation. | rhizobia are nitrogen-fixing bacteria that establish a symbiotic relationship with leguminous plants. to understand the mechanism by which rhizobia alter their metabolism to establish successful nitrogen-fixing symbiotic relationship with hosts, lotus japonicus were inoculated with mesorhizobium loti. bacteroids were isolated from nodules harvested at 2weeks (the early stage of nodule development), and at 3 and 4weeks (the intermediate stage of nodule development) post-inoculation. using a quant ... | 2015 | 25982383 |
| micro rna 172 (mir172) signals epidermal infection and is expressed in cells primed for bacterial invasion in lotus japonicus roots and nodules. | legumes interact with rhizobial bacteria to form nitrogen-fixing root nodules. host signalling following mutual recognition ensures a specific response, but is only partially understood. focusing on the stage of epidermal infection with mesorhizobium loti, we analysed endogenous small rnas (srnas) of the model legume lotus japonicus to investigate their involvement in host response regulation. we used illumina sequencing to annotate the l. japonicus srna-ome and isolate infection-responsive srna ... | 2015 | 25967282 |
| oricola cellulosilytica gen. nov., sp. nov., a cellulose-degrading bacterium of the family phyllobacteriaceae isolated from surface seashore water, and emended descriptions of mesorhizobium loti and phyllobacterium myrsinacearum. | a gram-stain negative, strictly aerobic, rod-shaped, non-spore-forming, motile cellulolytic bacterium, designated strain cc-amh-0(t), was isolated from surface seashore water of hualien, taiwan and subjected to polyphasic taxonomy. strain cc-amh-0(t) exhibited enzymatic saccharification of cellulose and active growth particularly during log-phase under nutrient-limited conditions, whereas enhanced saccharification was found in the declining growth phase under copiotrophic conditions. the novel s ... | 2015 | 25566955 |
| crystal structure of 5-formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid 5-dehydrogenase, an nad⁺-dependent dismutase from mesorhizobium loti. | 5-formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid 5-dehydrogenase (fhmpcdh) from mesorhizobium loti is the fifth enzyme in degradation pathway i for pyridoxine. the enzyme catalyzes a dismutation reaction: the oxidation of 5-formyl-3-hydroxy-2-methylpyridine 4-carboxylic acid (fhmpc) to 3-hydroxy-2-methylpyridine 4,5-dicarboxylic acid with nad(+) and reduction of fhmpc to 4-pyridoxic acid with nadh. fhmpcdh belongs to the l-3-hydroxyacyl-coa dehydrogenase (had) family. the crystal structure ... | 2015 | 25446130 |
| refined regio- and stereoselective hydroxylation of l-pipecolic acid by protein engineering of l-proline cis-4-hydroxylase based on the x-ray crystal structure. | enzymatic regio- and stereoselective hydroxylation are valuable for the production of hydroxylated chiral ingredients. proline hydroxylases are representative members of the nonheme fe(2+)/α-ketoglutarate-dependent dioxygenase family. these enzymes catalyze the conversion of l-proline into hydroxy-l-prolines (hyps). l-proline cis-4-hydroxylases (cis-p4hs) from sinorhizobium meliloti and mesorhizobium loti catalyze the hydroxylation of l-proline, generating cis-4-hydroxy-l-proline, as well as the ... | 2015 | 25171735 |
| chemically synthesized 58-mer lysm domain binds lipochitin oligosaccharide. | recognition of carbohydrates by proteins is a ubiquitous biochemical process. in legume-rhizobium symbiosis, lipochitin oligosaccharides, also referred to as nodulation (nod) factors, function as primary rhizobial signal molecules to trigger root nodule development. perception of these signal molecules is receptor mediated, and nod factor receptor 5 (nfr5) from the model legume lotus japonicus is predicted to contain three lysm domain binding sites. here we studied the interactions between nod f ... | 2014 | 25154732 |
| genes commonly involved in acid tolerance are not overexpressed in the plant microsymbiont mesorhizobium loti maff303099 upon acidic shock. | rhizobia are legume bacterial symbionts that fix nitrogen in the root nodules of plants. the aim of the present study was to investigate the global transcriptional response of rhizobia upon an acidic shock. changes in the transcriptome of cells of mesorhizobium loti strain maff303099 upon an acidic shock at ph 3 for 30 min were analysed. from a total of 7,231 protein-coding genes, 433 were found to be differentially expressed upon acidic shock, of which 322 were overexpressed. although most of t ... | 2014 | 24931309 |
| functional surface engineering by nucleotide-modulated potassium channel insertion into polymer membranes attached to solid supports. | planar solid-supported membranes based on amphiphilic block copolymers represent promising systems for the artificial creation of structural surfaces. here we introduce a method for engineering functional planar solid-supported membranes through insertion of active biomolecules. we show that membranes based on poly(dimethylsiloxane)-block-poly(2-methyl-2-oxazoline) (pdms-b-pmoxa) amphiphilic diblock copolymers, which mimic natural membranes, are suitable for hosting biomolecules. our strategy al ... | 2014 | 24912817 |
| knockdown of ljald1, agd2-like defense response protein 1, influences plant growth and nodulation in lotus japonicus. | the discovery of the enzyme l,l-diaminopimelate aminotransferase (ll-dap-at, ec 2.6.1.83) uncovered a unique step in the l-lysine biosynthesis pathway in plants. in arabidopsis thaliana, ll-dap-at has been shown to play a key role in plant-pathogen interactions by regulation of the salicylic acid (sa) signaling pathway. here, a full-length cdna of ll-dap-at named as ljald1 from lotus japonicus (regel) larsen was isolated. the deduced amino acid sequence shares 67% identity with the arabidopsis a ... | 2014 | 24797909 |
| microtubule array formation during root hair infection thread initiation and elongation in the mesorhizobium-lotus symbiosis. | nuclear migration during infection thread (it) development in root hairs is essential for legume-rhizobium symbiosis. however, little is known about the relationships between it formation, nuclear migration, and microtubule dynamics. to this aim, we used transgenic lotus japonicus expressing a fusion of the green fluorescent protein and tubulin-α6 from arabidopsis thaliana to visualize in vivo dynamics of cortical microtubules (cmt) and endoplasmic microtubules (emts) in root hairs in the presen ... | 2014 | 24488109 |
| glutamine synthetase i-deficiency in mesorhizobium loti differentially affects nodule development and activity in lotus japonicus. | in this study, we focused on the effect of glutamine synthetase (gsi) activity in mesorhizobium loti on the symbiosis between the host plant, lotus japonicus, and the bacteroids. we used a signature-tagged mutant of m. loti (stm30) with a transposon inserted into the gsi (mll0343) gene. the l. japonicus plants inoculated with stm30 had significantly more nodules, and the occurrence of senesced nodules was much higher than in plants inoculated with the wild-type. the acetylene reduction activity ... | 2014 | 24484964 |
| endoplasmic reticulum-targeted gfp reveals er remodeling in mesorhizobium-treated lotus japonicus root hairs during root hair curling and infection thread formation. | the endoplasmic reticulum (er) of the model legume lotus japonicus was visualized using green fluorescent protein (gfp) fused with the kdel sequence to investigate the changes in the root hair cortical er in the presence or absence of mesorhizobium loti using live fluorescence imaging. uninoculated root hairs displayed dynamic forms of er, ranging from a highly condensed form to an open reticulum. in the presence of m. loti, a highly dynamic condensed form of the er linked with the nucleus was f ... | 2014 | 24337802 |
| knockdown of ljipt3 influences nodule development in lotus japonicus. | cytokinins play important roles in legume-rhizobia symbiosis. here we report isolation of six genes encoding isopentenyl transferase (ipt) from lotus japonicus, which catalyze the rate-limiting step of cytokinin biosynthesis. the ljipt3 gene was found to be up-regulated in infected roots and mature nodules. histochemical analysis demonstrated expression of pro(ljipt3):gus (β-glucuronidase) in vegetative and reproductive organs, and was especially high in the vascular bundles of roots. when inocu ... | 2014 | 24285753 |
| the trehalose utilization gene thua ortholog in mesorhizobium loti does not influence competitiveness for nodulation on lotus spp. | competitiveness for nodulation is a desirable trait in rhizobia strains used as inoculant. in sinorhizobium meliloti 1021 mutation in either of the trehalose utilization genes thua or thub influences its competitiveness for root colonization and nodule occupancy depending on the interacting host. we have therefore investigated whether mutation in the thua ortholog in mesorhizobium loti maff303099 also leads to a similar competitive phenotype on its hosts. the results show that m. loti thua mutan ... | 2014 | 24142427 |
| two lotus japonicus symbiosis mutants impaired at distinct steps of arbuscule development. | arbuscular mycorrhiza (am) fungi form nutrient-acquiring symbioses with the majority of higher plants. nutrient exchange occurs via arbuscules, highly branched hyphal structures that are formed within root cortical cells. with a view to identifying host genes involved in am development, we isolated lotus japonicus am-defective mutants via a microscopic screen of an ethyl methanesulfonate-mutagenized population. a standardized mapping procedure was developed that facilitated positioning of the de ... | 2013 | 23627596 |
| crystal structure of pyridoxine 4-oxidase from mesorhizobium loti. | pyridoxine 4-oxidase (pnox) from mesorhizobium loti is a monomeric glucose-methanol-choline (gmc) oxidoreductase family enzyme, catalyzes fad-dependent oxidation of pyridoxine (pn) into pyridoxal, and is the first enzyme in pathway i for the degradation of pn. the tertiary structures of pnox with a c-terminal his6-tag and pnox-pyridoxamine (pm) complex were determined at 2.2å and at 2.1å resolutions, respectively. the overall structure consisted of fad-binding and substrate-binding domains. in t ... | 2013 | 23501672 |
| gene cloning and characterization of l-ribulose 3-epimerase from mesorhizobium loti and its application to rare sugar production. | a gene encoding l-ribulose 3-epimerase (l-re) from mesorhizobium loti, an important enzyme for rare sugar production by the izumoring strategy, was cloned and overexpressed. the enzyme showed highest activity toward l-ribulose (230 u/mg) among keto-pentoses and keto-hexoses. this is the first report on a ketose 3-epimerase showing highest activity toward keto-pentose. the optimum enzyme reaction conditions for l-re were determined to be sodium phosphate buffer (ph 8.0) at 60 °c. the enzyme showe ... | 2013 | 23470755 |
| down-regulation of nsp2 expression in developmentally young regions of lotus japonicus roots in response to rhizobial inoculation. | during the early 1980s, bauer and associates reported that nodulation potential in primary roots of soybean seedlings following inoculation with rhizobia was significantly reduced in developmentally younger regions. they suggested that this phenomenon might be due to a fast-acting regulatory mechanism in the host that prevented excessive nodulation. however, the molecular mechanism of this fast-acting regulatory response remains uncertain. here, we sought to elucidate components of this regulato ... | 2013 | 23335614 |
| conditional requirement for exopolysaccharide in the mesorhizobium-lotus symbiosis. | rhizobial surface polysaccharides are required for nodule formation on the roots of at least some legumes but the mechanisms by which they act are yet to be determined. as a first step to investigate the function of exopolysaccharide (eps) in the formation of determinate nodules, we isolated mesorhizobium loti mutants affected in various steps of eps biosynthesis and characterized their symbiotic phenotypes on two lotus spp. the wild-type m. loti r7a produced both high molecular weight eps and l ... | 2013 | 23134480 |
| a widely conserved molecular switch controls quorum sensing and symbiosis island transfer in mesorhizobium loti through expression of a novel antiactivator. | icemlsym(r7a) of mesorhizobium loti is an integrative and conjugative element (ice) that confers the ability to form a nitrogen-fixing symbiosis with lotus species. horizontal transfer is activated by trar and n-acyl-homoserine lactone (ahl), which can stimulate ice excision in 100% of cells. however, in wild-type cultures, the ice is excised at low frequency. here we show that qsem, a widely conserved ice-encoded protein, is an antiactivator of trar. mutation of qsem resulted in trar-dependent ... | 2013 | 23106190 |
| phenotypic and molecular characterization of indigenous rhizobia nodulating chickpea in india. | in a combined approach of phenotypic and genotypic characterization, 28 indigenous rhizobial isolates obtained from different chickpea growing regions in peninsular and northern india were analyzed for diversity. the field isolates were compared to two reference strains tal620 and upm-ca142 representing m. ciceri and m. mediterraneum respectively. phenotypic markers such as resistance to antibiotics, tolerance to salinity, temperature, ph, phosphate solubilization ability, growth rate and also s ... | 2012 | 22803324 |
| computational selection, identification and structural analysis of ω-aminotransferases with various substrate specificities from the genome sequence of mesorhizobium loti maff303099. | ω-aminotransferase (ω-at) is an important class of enzymes for the synthesis of chiral amines or β-amino acids. family profile analysis was applied to screen putative ω-ats from mesorhizobium loti maff303099, a nitrogen fixation bacterium that has a larger number of ats than other microorganisms. by family profile analysis, we selected 10 putative ω-ats according to e-value. the functions of the putative ω-ats were investigated by examining activities towards amines and/or β-amino acids. 10 puta ... | 2012 | 22785472 |
| negative regulation of ccamk is essential for symbiotic infection. | one of the earliest responses of legumes to symbiotic signalling is oscillation of the calcium concentration in the nucleoplasm of root epidermal cells. integration and decoding of the calcium-spiking signal involve a calcium- and calmodulin-dependent protein kinase (ccamk) and its phosphorylation substrates, such as cyclops. here we describe the lotus japonicus ccamk-14 mutant that originated from a har1-1 suppressor screen. the ccamk-14 mutation causes a serine to asparagine substitution at po ... | 2012 | 22775286 |
| molecular characterization of the lotus japonicus nrt1(ptr) and nrt2 families. | nitrate is an essential element for plant growth, both as a primary nutrient in the nitrogen assimilation pathway and as an important signal for plant development. low- and high-affinity transport systems are involved in the nitrate uptake from the soil and its distribution between different plant tissues. by an in silico search, we identified putative members of both systems in the model legume lotus japonicus. we investigated, by a time course analysis, the transcripts abundance in root tissue ... | 2012 | 22458810 |
| dual effect of mesorhizobium loti t3ss functionality on the symbiotic process. | mesorhizobium loti maff303099 has a functional type iii secretory system (t3ss) involved in the nodulation process on lotus tenuis and lotus japonicus. four putative m. loti t3ss effectors (mlr6358, mlr6331, mlr6361, and mlr6316) have been previously described, and it has been demonstrated that the n-terminal regions of mlr6361 and mlr6358 mediate the secretion via a t3ss. here, we demonstrate the capacity of mlr6316 and mlr6331 n-terminal regions to direct the secretion of a translational fusio ... | 2012 | 22428564 |
| the mll6786 gene encodes a repressor protein controlling the degradation pathway for vitamin b6 in mesorhizobium loti. | pyridoxine is converted to succinic semialdehyde, acetate, ammonia and co(2) through the actions of eight enzymes. the genes encoding the enzymes occur as a cluster on the chromosomal dna of mesorhizobium loti, a symbiotic nitrogen-fixing bacterium. here, it was found that disruption of the mll6786 gene, which is located between the genes encoding the first and eighth enzymes of the pathway, caused constitutive expression of the eight enzymes. the protein encoded by the mll6786 gene is a member ... | 2012 | 22276911 |