| a view to a kill: the bacterial type vi secretion system. | the bacterial type vi secretion system (t6ss) is an organelle that is structurally and mechanistically analogous to an intracellular membrane-attached contractile phage tail. recent studies determined that a rapid conformational change in the structure of a sheath protein complex propels t6ss spike and tube components along with antibacterial and antieukaryotic effectors out of predatory t6ss(+) cells and into prey cells. the contracted organelle is then recycled in an atp-dependent process. t6s ... | 2013 | 24332978 |
| a view to a kill: the bacterial type vi secretion system. | the bacterial type vi secretion system (t6ss) is an organelle that is structurally and mechanistically analogous to an intracellular membrane-attached contractile phage tail. recent studies determined that a rapid conformational change in the structure of a sheath protein complex propels t6ss spike and tube components along with antibacterial and antieukaryotic effectors out of predatory t6ss(+) cells and into prey cells. the contracted organelle is then recycled in an atp-dependent process. t6s ... | 2013 | 24332978 |
| global transcriptional response to heat shock of the legume symbiont mesorhizobium loti maff303099 comprises extensive gene downregulation. | rhizobia, the bacterial legume symbionts able to fix atmospheric nitrogen inside root nodules, have to survive in varied environmental conditions. the aim of this study was to analyse the transcriptional response to heat shock of mesorhizobium loti maff303099, a rhizobium with a large multipartite genome of 7.6 mb that nodulates the model legume lotus japonicus. using microarray analysis, extensive transcriptomic changes were detected in response to heat shock: 30% of the protein-coding genes we ... | 2013 | 24277738 |
| global transcriptional response to heat shock of the legume symbiont mesorhizobium loti maff303099 comprises extensive gene downregulation. | rhizobia, the bacterial legume symbionts able to fix atmospheric nitrogen inside root nodules, have to survive in varied environmental conditions. the aim of this study was to analyse the transcriptional response to heat shock of mesorhizobium loti maff303099, a rhizobium with a large multipartite genome of 7.6 mb that nodulates the model legume lotus japonicus. using microarray analysis, extensive transcriptomic changes were detected in response to heat shock: 30% of the protein-coding genes we ... | 2013 | 24277738 |
| transcriptional regulation by ferric uptake regulator (fur) in pathogenic bacteria. | in the ancient anaerobic environment, ferrous iron (fe(2+)) was one of the first metal cofactors. oxygenation of the ancient world challenged bacteria to acquire the insoluble ferric iron (fe(3+)) and later to defend against reactive oxygen species (ros) generated by the fenton chemistry. to acquire fe(3+), bacteria produce low-molecular weight compounds, known as siderophores, which have extremely high affinity for fe(3+). however, during infection the host restricts iron from pathogens by prod ... | 2013 | 24106689 |
| the mycobacterium tuberculosis secreted protein rv0203 transfers heme to membrane proteins mmpl3 and mmpl11. | mycobacterium tuberculosis is the causative agent of tuberculosis, which is becoming an increasingly global public health problem due to the rise of drug-resistant strains. while residing in the human host, m. tuberculosis needs to acquire iron for its survival. m. tuberculosis has two iron uptake mechanisms, one that utilizes non-heme iron and another that taps into the vast host heme-iron pool. to date, proteins known to be involved in mycobacterial heme uptake are rv0203, mmpl3, and mmpl11. w ... | 2013 | 23760277 |
| identification of a functional type vi secretion system in campylobacter jejuni conferring capsule polysaccharide sensitive cytotoxicity. | the pathogen campylobacter jejuni is the principal cause of bacterial food-borne infections. the mechanism(s) that contribute to bacterial survival and disease are still poorly understood. in other bacterial species, type vi secretion systems (t6ss) are increasingly recognized to contribute to bacterial pathogenesis by toxic effects on host cells or competing bacterial species. here we report the presence of a functional type vi secretion system in c. jejuni. proteome and genetic analyses reveal ... | 2013 | 23737749 |
| iron homeostasis in the rhodobacter genus. | metals are utilized for a variety of critical cellular functions and are essential for survival. however cells are faced with the conundrum of needing metals coupled with e fact that some metals, iron in particular are toxic if present in excess. maintaining metal homeostasis is therefore of critical importance to cells. in this review we have systematically analyzed sequenced genomes of three members of the rhodobacter genus, r. capsulatus sb1003, r. sphaeroides 2.4.1 and r. ferroxidans sw2 to ... | 2013 | 24382933 |
| the genome of the intracellular bacterium of the coastal bivalve, solemya velum: a blueprint for thriving in and out of symbiosis. | symbioses between chemoautotrophic bacteria and marine invertebrates are rare examples of living systems that are virtually independent of photosynthetic primary production. these associations have evolved multiple times in marine habitats, such as deep-sea hydrothermal vents and reducing sediments, characterized by steep gradients of oxygen and reduced chemicals. due to difficulties associated with maintaining these symbioses in the laboratory and culturing the symbiotic bacteria, studies of ch ... | 2014 | 25342549 |
| campylobacter jejuni gene cj0511 encodes a serine peptidase essential for colonisation. | according to merops peptidase database, campylobacter species encode 64 predicted peptidases. however, proteolytic properties of only a few of these proteins have been confirmed experimentally. in this study we identified and characterised a campylobacter jejuni gene cj0511 encoding a novel peptidase. the proteolytic activity associated with this enzyme was demonstrated in cell lysates. moreover, enzymatic studies conducted with a purified protein confirmed a prediction of it being a serine pept ... | 2014 | 24918062 |
| radical s-adenosylmethionine enzymes. | | 2014 | 24476342 |
| comparative metabolic systems analysis of pathogenic burkholderia. | burkholderia cenocepacia and burkholderia multivorans are opportunistic drug-resistant pathogens that account for the majority of burkholderia cepacia complex infections in cystic fibrosis patients and also infect other immunocompromised individuals. while they share similar genetic compositions, b. cenocepacia and b. multivorans exhibit important differences in pathogenesis. we have developed reconciled genome-scale metabolic network reconstructions of b. cenocepacia j2315 and b. multivorans at ... | 2014 | 24163337 |
| the pho regulon: a huge regulatory network in bacteria. | one of the most important achievements of bacteria is its capability to adapt to the changing conditions of the environment. the competition for nutrients with other microorganisms, especially in the soil, where nutritional conditions are more variable, has led bacteria to evolve a plethora of mechanisms to rapidly fine-tune the requirements of the cell. one of the essential nutrients that are normally found in low concentrations in nature is inorganic phosphate (pi). bacteria, as well as other ... | 2015 | 25983732 |
| contributions of sinorhizobium meliloti transcriptional regulator dksa to bacterial growth and efficient symbiosis with medicago sativa. | the stringent response, mediated by the (p)ppgpp synthetase rela and the rna polymerase-binding protein dksa, is triggered by limiting nutrient conditions. for some bacteria, it is involved in regulation of virulence. we investigated the role of two dksa-like proteins from the gram-negative nitrogen-fixing symbiont sinorhizobium meliloti in free-living culture and in interaction with its host plant medicago sativa the two paralogs, encoded by the genes smc00469 and smc00049, differ in the consti ... | 2016 | 26883825 |
| nodulation characterization and proteomic profiling of bradyrhizobium liaoningense ccbau05525 in response to water-soluble humic materials. | the lignite biodegradation procedure to produce water-soluble humic materials (wshm) with a penicillium stain was established by previous studies in our laboratory. this study researched the effects of wshm on the growth of bradyrhizobium liaoningense ccbau05525 and its nodulation on soybean. results showed that wshm enhanced the cell density of ccbau05525 in culture, and increased the nodule number, nodule fresh weight and nitrogenase activity of the inoculated soybean plants. then the chemical ... | 2015 | 26054030 |
| adhesins involved in attachment to abiotic surfaces by gram-negative bacteria. | during the first step of biofilm formation, initial attachment is dictated by physicochemical and electrostatic interactions between the surface and the bacterial envelope. depending on the nature of these interactions, attachment can be transient or permanent. to achieve irreversible attachment, bacterial cells have developed a series of surface adhesins promoting specific or nonspecific adhesion under various environmental conditions. this article reviews the recent advances in our understandi ... | 2015 | 26350310 |
| mob psychology. | | 2002 | 11807045 |
| stimulus perception in bacterial signal-transducing histidine kinases. | two-component signal-transducing systems are ubiquitously distributed communication interfaces in bacteria. they consist of a histidine kinase that senses a specific environmental stimulus and a cognate response regulator that mediates the cellular response, mostly through differential expression of target genes. histidine kinases are typically transmembrane proteins harboring at least two domains: an input (or sensor) domain and a cytoplasmic transmitter (or kinase) domain. they can be identifi ... | 2006 | 17158704 |
| comparative genomic reconstruction of transcriptional regulatory networks in bacteria. | | 2007 | 17636889 |
| look who's talking: communication and quorum sensing in the bacterial world. | for many years bacteria were considered primarily as autonomous unicellular organisms with little capacity for collective behaviour. however, we now appreciate that bacterial cells are in fact, highly communicative. the generic term 'quorum sensing' has been adopted to describe the bacterial cell-to-cell communication mechanisms which co-ordinate gene expression usually, but not always, when the population has reached a high cell density. quorum sensing depends on the synthesis of small molecule ... | 2007 | 17360280 |
| optimal tuning of bacterial sensing potential. | through production and sensing of small signal molecules, quorum sensing (qs) enables bacteria to detect changes in their density and regulate their functions accordingly. qs systems are tremendously diverse in terms of their specific sensory components, the biochemical and transport properties of signaling molecules, their target functions and the context in which qs-mediated functions are activated. cutting across this diversity, however, the central architecture of qs systems is universal; it ... | 2009 | 19584835 |
| protein secretion systems in bacterial-host associations, and their description in the gene ontology. | protein secretion plays a central role in modulating the interactions of bacteria with their environments. this is particularly the case when symbiotic bacteria (whether pathogenic, commensal or mutualistic) are interacting with larger host organisms. in the case of gram-negative bacteria, secretion requires translocation across the outer as well as the inner membrane, and a diversity of molecular machines have been elaborated for this purpose. a number of secreted proteins are destined to enter ... | 2009 | 19278550 |
| type vi secretion: not just for pathogenesis anymore. | type vi secretion systems (t6ss) have been studied primarily in the context of pathogenic bacteria-host interactions. recent data suggest, however, that these versatile secretion systems may also function to promote commensal or mutualistic relationships between bacteria and eukaryotes or to mediate cooperative or competitive interactions between bacteria. | 2010 | 20638635 |
| 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 |
| 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 |
| the phosphopantetheinyl transferases: catalysis of a post-translational modification crucial for life. | covering: up to 2013. although holo-acyl carrier protein synthase, acps, a phosphopantetheinyl transferase (pptase), was characterized in the 1960s, it was not until the publication of the landmark paper by lambalot et al. in 1996 that pptases garnered wide-spread attention being classified as a distinct enzyme superfamily. in the past two decades an increasing number of papers have been published on pptases ranging from identification, characterization, structure determination, mutagenesis, inh ... | 2014 | 24292120 |
| the twin arginine translocation system is essential for aerobic growth and full virulence of burkholderia thailandensis. | the twin arginine translocation (tat) system in bacteria is responsible for transporting folded proteins across the cytoplasmic membrane, and in some bacteria, tat-exported substrates have been linked to virulence. we report here that the tat machinery is present in burkholderia pseudomallei, b. mallei, and b. thailandensis, and we show that the system is essential for aerobic but not anaerobic growth. switching off of the tat system in b. thailandensis grown anaerobically resulted in filamentou ... | 2014 | 24214943 |
| genome-wide survey of two-component signal transduction systems in the plant growth-promoting bacterium azospirillum. | two-component systems (tcs) play critical roles in sensing and responding to environmental cues. azospirillum is a plant growth-promoting rhizobacterium living in the rhizosphere of many important crops. despite numerous studies about its plant beneficial properties, little is known about how the bacterium senses and responds to its rhizospheric environment. the availability of complete genome sequenced from four azospirillum strains (a. brasilense sp245 and cbg 497, a. lipoferum 4b and azospiri ... | 2015 | 26489830 |
| multiple chaperonins in bacteria--novel functions and non-canonical behaviors. | chaperonins are a class of molecular chaperones that assemble into a large double ring architecture with each ring constituting seven to nine subunits and enclosing a cavity for substrate encapsulation. the well-studied escherichia coli chaperonin groel binds non-native substrates and encapsulates them in the cavity thereby sequestering the substrates from unfavorable conditions and allowing the substrates to fold. using this mechanism, groel assists folding of about 10-15 % of cellular proteins ... | 2015 | 25986150 |
| total (bio)synthesis: strategies of nature and of chemists. | the biosynthetic pathways to a number of natural products have been reconstituted in vitro using purified enzymes. many of these molecules have also been synthesized by organic chemists. here we compare the strategies used by nature and by chemists to reveal the underlying logic and success of each total synthetic approach for some exemplary molecules with diverse biosynthetic origins. | 2010 | 21495259 |
| a subset of the diverse cog0523 family of putative metal chaperones is linked to zinc homeostasis in all kingdoms of life. | cog0523 proteins are, like the nickel chaperones of the ureg family, part of the g3e family of gtpases linking them to metallocenter biosynthesis. even though the first cog0523-encoding gene, cobw, was identified almost 20 years ago, little is known concerning the function of other members belonging to this ubiquitous family. | 2009 | 19822009 |
| biosynthesis of polyketide synthase extender units. | this review covers the biosynthesis of extender units that are utilized for the assembly of polyketides by polyketide synthases. the metabolic origins of each of the currently known polyketide synthase extender units are covered. | 2009 | 19374124 |
| solving the problem: genome annotation standards before the data deluge. | the promise of genome sequencing was that the vast undiscovered country would be mapped out by comparison of the multitude of sequences available and would aid researchers in deciphering the role of each gene in every organism. researchers recognize that there is a need for high quality data. however, different annotation procedures, numerous databases, and a diminishing percentage of experimentally determined gene functions have resulted in a spectrum of annotation quality. ncbi in collaboratio ... | 2011 | 22180819 |
| discovering the unknown: improving detection of novel species and genera from short reads. | high-throughput sequencing technologies enable metagenome profiling, simultaneous sequencing of multiple microbial species present within an environmental sample. since metagenomic data includes sequence fragments ("reads") from organisms that are absent from any database, new algorithms must be developed for the identification and annotation of novel sequence fragments. homology-based techniques have been modified to detect novel species and genera, but, composition-based methods, have not been ... | 2011 | 21541181 |
| recent advances in bacterial heme protein biochemistry. | recent progress in genetics, fed by the burst in genome sequence data, has led to the identification of a host of novel bacterial heme proteins that are now being characterized in structural and mechanistic terms. the following short review highlights very recent work with bacterial heme proteins involved in the uptake, biosynthesis, degradation, and use of heme in respiration and sensing. | 2011 | 21339081 |
| 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 |
| molecular cloning, expression of mind gene from lactobacillus acidophilus vtcc-b-871 and analyses to identify lactobacillus rhamnosus pn04 from vietnam hottuynia cordata thunb. | the mind gene encoding an inhibitor cell division mind homolog from lactobacillus acidophilus vtcc-b-871 was cloned. we showed that there were 97 % homology between mind genes of l. acidophilus vtcc-b-871 and lactobacillus rhamnosus gg and lactobacillus rhamnosus lc705. based on the analysis of the dna sequence data from the l. rhamnosus genome project and sequenced mind gene of l. acidophilus vtcc-b-871, a pair of primers was designed to identified the different mind genes from l. acidophilus a ... | 2013 | 24426140 |
| analysis of stable low-molecular-weight rna profiles of members of the family rhizobiaceae. | staircase electrophoresis in polyacrylamide gels was used to analyze the stable low-molecular-weight (lmw) rna profiles of 24 type strains belonging to the family rhizobiaceae. this new electrophoretic technique results in good separation of the molecules forming the lmw rna profiles. differences in the number and distribution of the rna bands in these profiles allowed us to identify differences among the 24 strains assayed. species assignments based on lmw rnas proved to be consistent with the ... | 1998 | 9575134 |
| reactive oxygen species and ethylene play a positive role in lateral root base nodulation of a semiaquatic legume. | lateral root base nodulation on the tropical, semiaquatic legume sesbania rostrata results from two coordinated, nod factor-dependent processes: formation of intercellular infection pockets and induction of cell division. infection pocket formation is associated with cell death and production of hydrogen peroxide. pharmacological experiments showed that ethylene and reactive oxygen species mediate nod factor responses and are required for nodule initiation, whereby induction of division and infe ... | 2003 | 12975522 |
| genomic and evolutionary comparisons of diazotrophic and pathogenic bacteria of the order rhizobiales. | species belonging to the rhizobiales are intriguing and extensively researched for including both bacteria with the ability to fix nitrogen when in symbiosis with leguminous plants and pathogenic bacteria to animals and plants. similarities between the strategies adopted by pathogenic and symbiotic rhizobiales have been described, as well as high variability related to events of horizontal gene transfer. although it is well known that chromosomal rearrangements, mutations and horizontal gene tra ... | 2010 | 20144182 |
| lon protease of azorhizobium caulinodans ors571 is required for suppression of reb gene expression. | bacterial lon proteases play important roles in a variety of biological processes in addition to housekeeping functions. in this study, we focused on the lon protease of azorhizobium caulinodans, which can fix nitrogen both during free-living growth and in stem nodules of the legume sesbania rostrata. the nitrogen fixation activity of an a. caulinodans lon mutant in the free-living state was not significantly different from that of the wild-type strain. however, the stem nodules formed by the lo ... | 2012 | 22752172 |
| defining sequence space and reaction products within the cyanuric acid hydrolase (atzd)/barbiturase protein family. | cyanuric acid hydrolases (atzd) and barbiturases are homologous, found almost exclusively in bacteria, and comprise a rare protein family with no discernible linkage to other protein families or an x-ray structural class. there has been confusion in the literature and in genome projects regarding the reaction products, the assignment of individual sequences as either cyanuric acid hydrolases or barbiturases, and spurious connection of this family to another protein family. the present study has ... | 2012 | 22730121 |
| expression of phenazine biosynthetic genes during the arbuscular mycorrhizal symbiosis of glomus intraradices. | to explore the molecular mechanisms that prevail during the establishment of the arbuscular mycorrhiza symbiosis involving the genus glomus, we transcriptionally analysed spores of glomus intraradices be3 during early hyphal growth. among 458 transcripts initially identified as being expressed at presymbiotic stages, 20% of sequences had homology to previously characterized eukaryotic genes, 30% were homologous to fungal coding sequences, and 9% showed homology to previously characterized bacter ... | 2012 | 24031884 |
| comparative genomics of rhizobia nodulating soybean suggests extensive recruitment of lineage-specific genes in adaptations. | the rhizobium-legume symbiosis has been widely studied as the model of mutualistic evolution and the essential component of sustainable agriculture. extensive genetic and recent genomic studies have led to the hypothesis that many distinct strategies, regardless of rhizobial phylogeny, contributed to the varied rhizobium-legume symbiosis. we sequenced 26 genomes of sinorhizobium and bradyrhizobium nodulating soybean to test this hypothesis. the bradyrhizobium core genome is disproportionally enr ... | 2012 | 22586130 |
| nontarget effects of foliar fungicide application on the rhizosphere: diversity of nifh gene and nodulation in chickpea field. | this study explores nontarget effects of fungicide application on field-grown chickpea. | 2012 | 22335393 |
| nad(p)+-malic enzyme mutants of sinorhizobium sp. strain ngr234, but not azorhizobium caulinodans ors571, maintain symbiotic n2 fixation capabilities. | c(4)-dicarboxylic acids appear to be metabolized via the tricarboxylic acid (tca) cycle in n(2)-fixing bacteria (bacteroids) within legume nodules. in sinorhizobium meliloti bacteroids from alfalfa, nad(+)-malic enzyme (dme) is required for n(2) fixation, and this activity is thought to be required for the anaplerotic synthesis of pyruvate. in contrast, in the pea symbiont rhizobium leguminosarum, pyruvate synthesis occurs via either dme or a pathway catalyzed by phosphoenolpyruvate carboxykinas ... | 2012 | 22307295 |
| thiol synthetases of legumes: immunogold localization and differential gene regulation by phytohormones. | in plants and other organisms, glutathione (gsh) biosynthesis is catalysed sequentially by γ-glutamylcysteine synthetase (γecs) and glutathione synthetase (gshs). in legumes, homoglutathione (hgsh) can replace gsh and is synthesized by γecs and a specific homoglutathione synthetase (hgshs). the subcellular localization of the enzymes was examined by electron microscopy in several legumes and gene expression was analysed in lotus japonicus plants treated for 1-48 h with 50 μm of hormones. immunog ... | 2012 | 22442424 |
| the genetics of symbiotic nitrogen fixation: comparative genomics of 14 rhizobia strains by resolution of protein clusters. | the symbiotic relationship between legumes and nitrogen fixing bacteria is critical for agriculture, as it may have profound impacts on lowering costs for farmers, on land sustainability, on soil quality, and on mitigation of greenhouse gas emissions. however, despite the importance of the symbioses to the global nitrogen cycling balance, very few rhizobial genomes have been sequenced so far, although there are some ongoing efforts in sequencing elite strains. in this study, the genomes of fourt ... | 2012 | 24704847 |
| unusual spectral properties of bacteriophytochrome agp2 result from a deprotonation of the chromophore in the red-absorbing form pr. | phytochromes are widely distributed photoreceptors with a bilin chromophore that undergo a typical reversible photoconversion between the two spectrally different forms, pr and pfr. the phytochrome agp2 from agrobacterium tumefaciens belongs to the group of bathy phytochromes that have a pfr ground state as a result of the pr to pfr dark conversion. agp2 has untypical spectral properties in the pr form reminiscent of a deprotonated chromophore as confirmed by resonance raman spectroscopy. uv/vis ... | 2013 | 24036118 |
| the sinorhizobium meliloti essential porin ropa1 is a target for numerous bacteriophages. | the symbiotic nitrogen-fixing bacterium sinorhizobium meliloti harbors a gene, smc02396, which encodes a predicted outer membrane porin that is conserved in many symbiotic and pathogenic bacteria in the order rhizobiales. here, this gene (renamed ropa1) is shown to be required for infection by two commonly utilized transducing bacteriophages (φm12 and n3). mapping of s. meliloti mutations conferring resistance to φm12, n3, or both phages simultaneously revealed diverse mutations mapping within t ... | 2013 | 23749981 |
| cyanuric acid hydrolase: evolutionary innovation by structural concatenation. | the cyanuric acid hydrolase, atzd, is the founding member of a newly identified family of ring-opening amidases. we report the first x-ray structure for this family, which is a novel fold (termed the 'toblerone' fold) that likely evolved via the concatenation of monomers of the trimeric yjgf superfamily and the acquisition of a metal binding site. structures of atzd with bound substrate (cyanuric acid) and inhibitors (phosphate, barbituric acid and melamine), along with mutagenesis studies, allo ... | 2013 | 23651355 |
| 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 |
| 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 |
| nitrogen-fixing rhizobial strains isolated from common bean seeds: phylogeny, physiology, and genome analysis. | rhizobial bacteria are commonly found in soil but also establish symbiotic relationships with legumes, inhabiting the root nodules, where they fix nitrogen. endophytic rhizobia have also been reported in the roots and stems of legumes and other plants. we isolated several rhizobial strains from the nodules of noninoculated bean plants and looked for their provenance in the interiors of the seeds. nine isolates were obtained, covering most known bean symbiont species, which belong to the rhizobiu ... | 2014 | 25002426 |
| homogalacturonan-modifying enzymes: structure, expression, and roles in plants. | understanding the changes affecting the plant cell wall is a key element in addressing its functional role in plant growth and in the response to stress. pectins, which are the main constituents of the primary cell wall in dicot species, play a central role in the control of cellular adhesion and thereby of the rheological properties of the wall. this is likely to be a major determinant of plant growth. how the discrete changes in pectin structure are mediated is thus a key issue in our understa ... | 2014 | 25056773 |
| riboregulation in plant-associated α-proteobacteria. | the symbiotic α-rhizobia sinorhizobium meliloti, bradyrhizobium japonicum, rhizobium etli and the related plant pathogen agrobacterium tumefaciens are important model organisms for studying plant-microbe interactions. these metabolically versatile soil bacteria are characterized by complex lifestyles and large genomes. here we summarize the recent knowledge on their small non-coding rnas (srnas) including conservation, function, and interaction of the srnas with the rna chaperone hfq. in each of ... | 2014 | 25003187 |
| mutation of prar in rhizobium leguminosarum enhances root biofilms, improving nodulation competitiveness by increased expression of attachment proteins. | in rhizobium leguminosarum bv. viciae, quorum-sensing is regulated by cinr, which induces the cinis operon. cini synthesizes an ahl, whereas cins inactivates prar, a repressor. mutation of prar enhanced biofilms in vitro. we developed a light (lux)-dependent assay of rhizobial attachment to roots and demonstrated that mutation of prar increased biofilms on pea roots. the prar mutant out-competed wild-type for infection of pea nodules in mixed inoculations. analysis of gene expression by microarr ... | 2014 | 24942546 |
| the complete genome of burkholderia phenoliruptrix strain br3459a, a symbiont of mimosa flocculosa: highlighting the coexistence of symbiotic and pathogenic genes. | burkholderia species play an important ecological role related to xenobiosis, the promotion of plant growth, the biocontrol of agricultural diseases, and symbiotic and non-symbiotic biological nitrogen fixation. here, we highlight our study as providing the first complete genome of a symbiotic strain of b. phenoliruptrix, br3459a (=cla1), which was originally isolated in brazil from nodules of mimosa flocculosa and is effective in fixing nitrogen in association with this leguminous species. | 2014 | 24972629 |
| phenotypic characterization of astragalus glycyphyllos symbionts and their phylogeny based on the 16s rdna sequences and rflp of 16s rrna gene. | in this study, the nitrogen fixing astragalus glycyphyllos symbionts were characterized by phenotypic properties, restriction fragment length polymorphism (rflp), and sequences of 16s rdna. the generation time of a. glycyphyllos rhizobia in yeast extract mannitol medium was in the range 4-6 h. the studied isolates exhibited a low resistance to antibiotics, a moderate tolerance to nacl, assimilated di- and trisaccharides, and produced acid in medium containing mannitol as a sole carbon source. in ... | 2014 | 24710996 |
| the growth of steroidobacter agariperforans sp. nov., a novel agar-degrading bacterium isolated from soil, is enhanced by the diffusible metabolites produced by bacteria belonging to rhizobiales. | an agar-degrading bacterium was isolated from soil collected in a vegetable cropping field. the growth of this isolate was enhanced by supplying culture supernatants of bacteria belonging to the order rhizobiales. phylogenetic analysis based on 16s rrna gene sequences indicated the novel bacterium, strain ka5-b(t), belonged to the genus steroidobacter in gammaproteobacteria, but differed from its closest relative, steroidobacter denitrificans fs(t), at the species level with 96.5% similarity. st ... | 2014 | 24621511 |
| genome-wide profiling of hfq-binding rnas uncovers extensive post-transcriptional rewiring of major stress response and symbiotic regulons in sinorhizobium meliloti. | the rna chaperone hfq is a global post-transcriptional regulator in bacteria. here, we used rnaseq to analyze rna populations from the legume symbiont sinorhizobium meliloti that were co-immunoprecipitated (coip-rna) with a flag-tagged hfq in five growth/stress conditions. hfq-bound transcripts (1315) were largely identified in stressed bacteria and derived from small rnas (srnas), both trans-encoded (6.4%) and antisense (asrnas; 6.3%), and mrnas (86%). pull-down with hfq recovered a small propo ... | 2014 | 24786641 |
| candidatus frankia datiscae dg1, the actinobacterial microsymbiont of datisca glomerata, expresses the canonical nod genes nodabc in symbiosis with its host plant. | frankia strains are nitrogen-fixing soil actinobacteria that can form root symbioses with actinorhizal plants. phylogenetically, symbiotic frankiae can be divided into three clusters, and this division also corresponds to host specificity groups. the strains of cluster ii which form symbioses with actinorhizal rosales and cucurbitales, thus displaying a broad host range, show suprisingly low genetic diversity and to date can not be cultured. the genome of the first representative of this cluster ... | 2015 | 26020781 |
| role of root microbiota in plant productivity. | the growing human population requires increasing amounts of food, but modern agriculture has limited possibilities for increasing yields. new crop varieties may be bred to have increased yields and be more resistant to environmental stress and pests. however, they still require fertilization to supplement essential nutrients that are normally limited in the soil. soil microorganisms present an opportunity to reduce the requirement for inorganic fertilization in agriculture. microorganisms, due t ... | 2015 | 25908654 |
| genome analysis of a novel bradyrhizobium sp. doa9 carrying a symbiotic plasmid. | bradyrhizobium sp. doa9 isolated from the legume aeschynomene americana exhibited a broad host range and divergent nodulation (nod) genes compared with other members of the bradyrhizobiaceae. genome analysis of doa9 revealed that its genome comprised a single chromosome of 7.1 mbp and a plasmid of 0.7 mbp. the chromosome showed highest similarity with that of the nod gene-harboring soybean symbiont b. japonicum usda110, whereas the plasmid showed highest similarity with pbbta01 of the nod gene-l ... | 2015 | 25710540 |
| new insights into nod factor biosynthesis: analyses of chitooligomers and lipo-chitooligomers of rhizobium sp. irbg74 mutants. | soil-dwelling, nitrogen-fixing rhizobia signal their presence to legume hosts by secreting lipo-chitooligomers (lcos) that are decorated with a variety of chemical substituents. it has long been assumed, but never empirically shown, that the lco backbone is synthesized first by nodc, nodb, and noda, followed by addition of one or more substituents by other nod proteins. by analyzing a collection of in-frame deletion mutants of key nod genes in the bacterium rhizobium sp. irbg74 by mass spectrome ... | 2016 | 27623438 |
| regulation of polyhydroxybutyrate synthesis in the soil bacterium bradyrhizobium diazoefficiens. | polyhydroxybutyrate (phb) is a carbon and energy reserve polymer in various prokaryotic species. we determined that, when grown with mannitol as the sole carbon source, bradyrhizobium diazoefficiens produces a homopolymer composed only of 3-hydroxybutyrate units (phb). conditions of oxygen limitation (such as microoxia, oxic stationary phase, and bacteroids inside legume nodules) were permissive for the synthesis of phb, which was observed as cytoplasmic granules. to study the regulation of phb ... | 2016 | 27208130 |
| bacterial molecular signals in the sinorhizobium fredii-soybean symbiosis. | sinorhizobium (ensifer) fredii (s. fredii) is a rhizobial species exhibiting a remarkably broad nodulation host-range. thus, s. fredii is able to effectively nodulate dozens of different legumes, including plants forming determinate nodules, such as the important crops soybean and cowpea, and plants forming indeterminate nodules, such as glycyrrhiza uralensis and pigeon-pea. this capacity of adaptation to different symbioses makes the study of the molecular signals produced by s. fredii strains ... | 2016 | 27213334 |
| ancient evolution and recent evolution converge for the biodegradation of cyanuric acid and related triazines. | cyanuric acid was likely present on prebiotic earth, may have been a component of early genetic materials, and is synthesized industrially today on a scale of more than one hundred million pounds per year in the united states. in light of this, it is not surprising that some bacteria and fungi have a metabolic pathway that sequentially hydrolyzes cyanuric acid and its metabolites to release the nitrogen atoms as ammonia to support growth. the initial reaction that opens the s-triazine ring is ca ... | 2016 | 26729715 |
| using synthetic biology to increase nitrogenase activity. | nitrogen fixation has been established in protokaryotic model escherichia coli by transferring a minimal nif gene cluster composed of 9 genes (nifb, nifh, nifd, nifk, nife, nifn, nifx, hesa and nifv) from paenibacillus sp. wly78. however, the nitrogenase activity in the recombinant e. coli 78-7 is only 10 % of that observed in wild-type paenibacillus. thus, it is necessary to increase nitrogenase activity through synthetic biology. | 2016 | 26897628 |
| genetic analysis reveals the essential role of nitrogen phosphotransferase system components in sinorhizobium fredii ccbau 45436 symbioses with soybean and pigeonpea plants. | the nitrogen phosphotransferase system (pts(ntr)) consists of ei(ntr), npr, and eiia(ntr). the active phosphate moiety derived from phosphoenolpyruvate is transferred through ei(ntr) and npr to eiia(ntr). sinorhizobium fredii can establish a nitrogen-fixing symbiosis with the legume crops soybean (as determinate nodules) and pigeonpea (as indeterminate nodules). in this study, s. fredii strains with mutations in ptsp and ptso (encoding ei(ntr) and npr, respectively) formed ineffective nodules on ... | 2016 | 26682851 |
| the lps o-antigen in photosynthetic bradyrhizobium strains is dispensable for the establishment of a successful symbiosis with aeschynomene legumes. | the photosynthetic bradyrhizobia are able to use a nod-factor independent process to induce nitrogen-fixing nodules on some semi-aquatic aeschynomene species. these bacteria display a unique lps o-antigen composed of a new sugar, the bradyrhizose that is regarded as a key symbiotic factor due to its non-immunogenic character. in this study, to check this hypothesis, we isolated mutants affected in the o-antigen synthesis by screening a transposon mutant library of the ors285 strain for clones al ... | 2016 | 26849805 |
| oxygene: an innovative platform for investigating oxidative-response genes in whole prokaryotic genomes. | oxidative stress is a common stress encountered by living organisms and is due to an imbalance between intracellular reactive oxygen and nitrogen species (ros, rns) and cellular antioxidant defence. to defend themselves against ros/rns, bacteria possess a subsystem of detoxification enzymes, which are classified with regard to their substrates. to identify such enzymes in prokaryotic genomes, different approaches based on similarity, enzyme profiles or patterns exist. unfortunately, several prob ... | 2008 | 19117520 |
| iron response regulator protein irrb in magnetospirillum gryphiswaldense msr-1 helps control the iron/oxygen balance, oxidative stress tolerance, and magnetosome formation. | magnetotactic bacteria are capable of forming nanosized, membrane-enclosed magnetosomes under iron-rich and oxygen-limited conditions. the complete genomic sequence of magnetospirillum gryphiswaldense strain msr-1 has been analyzed and found to contain five fur homologue genes whose protein products are predicted to be involved in iron homeostasis and the response to oxidative stress. of these, only the mgmsrv2_3149 gene (irrb) was significantly downregulated under high-iron and low-oxygen condi ... | 2015 | 26386052 |
| the lysr-type transcription factor hbrl is a global regulator of iron homeostasis and porphyrin synthesis in rhodobacter capsulatus. | the purple bacterium rhodobacter capsulatus is unique among rhodobacteriacae as it contains a putative iron response regulator (irr) but does not possess a copy of the ferric uptake regulator (fur). interestingly, an in-frame deletion mutant of irr shows no major role in iron homeostasis. instead, we showed that the previously identified activator of haem gene expression hbrl is a crucial regulator of iron homeostasis. we demonstrated that an hbrl deletion strain is unable to grow in iron-limite ... | 2013 | 24134691 |
| interplay of metal ions and urease. | urease, the first enzyme to be crystallized, contains a dinuclear nickel metallocenter that catalyzes the decomposition of urea to produce ammonia, a reaction of great agricultural and medical importance. several mechanisms of urease catalysis have been proposed on the basis of enzyme crystal structures, model complexes, and computational efforts, but the precise steps in catalysis and the requirement of nickel versus other metals remain unclear. purified bacterial urease is partially activated ... | 2009 | 20046957 |
| comparative genomics of regulation of heavy metal resistance in eubacteria. | heavy metal resistance (hmr) in eubacteria is regulated by a variety of systems including transcription factors from the merr family (cog0789). the hmr systems are characterized by the complex signal structure (strong palindrome within a 19 or 20 bp promoter spacer), and usually consist of transporter and regulator genes. some hmr regulons also include detoxification systems. the number of sequenced bacterial genomes is constantly increasing and even though hmr resistance regulons of the cog0789 ... | 2006 | 16753059 |
| marine metagenomics: strategies for the discovery of novel enzymes with biotechnological applications from marine environments. | metagenomic based strategies have previously been successfully employed as powerful tools to isolate and identify enzymes with novel biocatalytic activities from the unculturable component of microbial communities from various terrestrial environmental niches. both sequence based and function based screening approaches have been employed to identify genes encoding novel biocatalytic activities and metabolic pathways from metagenomic libraries. while much of the focus to date has centred on terre ... | 2008 | 18717988 |
| marine metagenomics: new tools for the study and exploitation of marine microbial metabolism. | the marine environment is extremely diverse, with huge variations in pressure and temperature. nevertheless, life, especially microbial life, thrives throughout the marine biosphere and microbes have adapted to all the divergent environments present. large scale dna sequence based approaches have recently been used to investigate the marine environment and these studies have revealed that the oceans harbor unprecedented microbial diversity. novel gene families with representatives only within su ... | 2010 | 20411118 |
| molecular insights into cold active polygalacturonase enzyme for its potential application in food processing. | pectin is a complex structural heteropolysaccharide that require numerous pectinolytic enzymes for its complete degradation. polygalacturonase from mesophilic or thermophilic origin are being widely used in fruit and vegetable processing in the recent decades to degrade pectic substances. recently cold active pectinases are finding added advantages over meso and thermophilic counterparts, to use in industrial scale particularly in food processing industry. they facilitate in conservation of seve ... | 2014 | 26344963 |
| molecular insights into cold active polygalacturonase enzyme for its potential application in food processing. | pectin is a complex structural heteropolysaccharide that require numerous pectinolytic enzymes for its complete degradation. polygalacturonase from mesophilic or thermophilic origin are being widely used in fruit and vegetable processing in the recent decades to degrade pectic substances. recently cold active pectinases are finding added advantages over meso and thermophilic counterparts, to use in industrial scale particularly in food processing industry. they facilitate in conservation of seve ... | 2014 | 26344963 |
| the 52nd annual wind river conference on prokaryotic biology--2008. | | 2008 | 18931109 |
| deciphering evolutionary mechanisms between mutualistic and pathogenic symbioses. | the continuum between mutualistic and pathogenic symbioses has been an underlying theme for understanding the evolution of infection and disease in a number of eukaryotic-microbe associations. the ability to monitor and then predict the spread of infectious diseases may depend upon our knowledge and capabilities of anticipating the behavior of virulent pathogens by studying related, benign symbioses. for instance, the ability of a symbiotic species to infect, colonize, and proliferate efficientl ... | 2008 | 19655044 |
| analysis and comparison of the pan-genomic properties of sixteen well-characterized bacterial genera. | the increasing availability of whole genome sequences allows the gene or protein content of different organisms to be compared, leading to burgeoning interest in the relatively new subfield of pan-genomics. however, while several studies have analyzed protein content relationships in specific groups of bacteria, there has yet to be a study that provides a general characterization of protein content relationships in a broad range of bacteria. | 2010 | 20942950 |
| 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 |
| 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 |
| 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 |
| genome, integration, and transduction of a novel temperate phage of helicobacter pylori. | helicobacter pylori is a common human pathogen that has been identified to be carcinogenic. this study isolated the temperate bacteriophage 1961p from the lysate of a clinical strain of h. pylori isolated in taiwan. the bacteriophage has an icosahedral head and a short tail, typical of the podoviridae family. its double-stranded dna genome is 26,836 bp long and has 33 open reading frames. only 9 of the predicted proteins have homologs of known functions, while the remaining 24 are only similar t ... | 2012 | 22696647 |
| sinorhizobium meliloti exor is the target of periplasmic proteolysis. | sinorhizobium meliloti exor regulates the production of succinoglycan and flagella through the exos/chvi two-component regulatory system. exor has been proposed to inhibit the exos sensor through direct interaction in the periplasm. to understand how exor suppression of exos is relieved, which is required for the expression of exos/chvi-regulated symbiosis genes, we characterized wild-type exor and exor95 mutant proteins. in addition to the previously identified precursor and mature forms of exo ... | 2012 | 22636773 |
| light regulates attachment, exopolysaccharide production, and nodulation in rhizobium leguminosarum through a lov-histidine kinase photoreceptor. | rhizobium leguminosarum is a soil bacterium that infects root hairs and induces the formation of nitrogen-fixing nodules on leguminous plants. light, oxygen, and voltage (lov)-domain proteins are blue-light receptors found in higher plants and many algae, fungi, and bacteria. the genome of r. leguminosarum bv. viciae 3841, a pea-nodulating endosymbiont, encodes a sensor histidine kinase containing a lov domain at the n-terminal end (r-lov-hk). r-lov-hk has a typical lov domain absorption spectru ... | 2012 | 22773814 |
| the lovk-lovr two-component system is a regulator of the general stress pathway in caulobacter crescentus. | a conserved set of regulators control the general stress response in caulobacter crescentus, including σ(t), its anti-σ factor nepr, the anti-anti-σ factor phyr, and the transmembrane sensor kinase phyk. we report that the soluble histidine kinase lovk and the single-domain response regulator lovr also function within the c. crescentus general stress pathway. our genetic data support a model in which lovk-lovr functions upstream of σ(t) by controlling the phosphorylation state and thus anti-anti ... | 2012 | 22408156 |
| a comparative genomics screen identifies a sinorhizobium meliloti 1021 sodm-like gene strongly expressed within host plant nodules. | we have used the genomic data in the integrated microbial genomes system of the department of energy's joint genome institute to make predictions about rhizobial open reading frames that play a role in nodulation of host plants. the genomic data was screened by searching for orfs conserved in α-proteobacterial rhizobia, but not conserved in closely-related non-nitrogen-fixing α-proteobacteria. | 2012 | 22587634 |
| the lipopolysaccharide core of brucella abortus acts as a shield against innate immunity recognition. | innate immunity recognizes bacterial molecules bearing pathogen-associated molecular patterns to launch inflammatory responses leading to the activation of adaptive immunity. however, the lipopolysaccharide (lps) of the gram-negative bacterium brucella lacks a marked pathogen-associated molecular pattern, and it has been postulated that this delays the development of immunity, creating a gap that is critical for the bacterium to reach the intracellular replicative niche. we found that a b. abort ... | 2012 | 22589715 |
| fur in magnetospirillum gryphiswaldense influences magnetosomes formation and directly regulates the genes involved in iron and oxygen metabolism. | magnetospirillum gryphiswaldense strain msr-1 has the unique capability of taking up large amounts of iron and synthesizing magnetosomes (intracellular magnetic particles composed of fe(3)o(4)). the unusual high iron content of msr-1 makes it a useful model for studying biological mechanisms of iron uptake and homeostasis. the ferric uptake regulator (fur) protein plays a key role in maintaining iron homeostasis in many bacteria. we identified and characterized a fur-homologous gene (mgr_1314) i ... | 2012 | 22238623 |
| whole-proteome analysis of twelve species of alphaproteobacteria links four pathogens. | thousands of whole-genome and whole-proteome sequences have been made available through advances in sequencing technology, and sequences of millions more organisms will become available in the coming years. this wealth of genetic information will provide numerous opportunities to enhance our understanding of these organisms including a greater understanding of relationships among species. researchers have used 16s rrna and other gene sequences to study the evolutionary origins of bacteria, but t ... | 2013 | 25437336 |
| identification and characterization of ribn, a novel family of riboflavin transporters from rhizobium leguminosarum and other proteobacteria. | rhizobia are symbiotic bacteria able to invade and colonize the roots of legume plants, inducing the formation of nodules, where bacteria reduce atmospheric nitrogen (n2) to ammonia (nh3). riboflavin availability influences the capacity of rhizobia to survive in the rhizosphere and to colonize roots. in this study, we identified the rl1692 gene of rhizobium leguminosarum downstream of a flavin mononucleotide (fmn) riboswitch. rl1692 encodes a putative transmembrane permease with two eama domains ... | 2013 | 23935051 |
| members of the sinorhizobium meliloti chvi regulon identified by a dna binding screen. | the sinorhizobium meliloti exos/chvi two component regulatory system is required for n2-fixing symbiosis and exopolysaccharide synthesis. orthologous systems are present in other alphaproteobacteria, and in many instances have been shown to be necessary for normal interactions with corresponding eukaryotic hosts. only a few transcriptional regulation targets have been determined, and as a result there is limited understanding of the mechanisms that are controlled by the system. | 2013 | 23758731 |
| light regulation of swarming motility in pseudomonas syringae integrates signaling pathways mediated by a bacteriophytochrome and a lov protein. | the biological and regulatory roles of photosensory proteins are poorly understood for nonphotosynthetic bacteria. the foliar bacterial pathogen pseudomonas syringae has three photosensory protein-encoding genes that are predicted to encode the blue-light-sensing lov (light, oxygen, or voltage) histidine kinase (lov-hk) and two red/far-red-light-sensing bacteriophytochromes, bphp1 and bphp2. we provide evidence that lov-hk and bphp1 form an integrated network that regulates swarming motility in ... | 2013 | 23760465 |
| 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 |
| molecular modeling and computational analyses suggests that the sinorhizobium meliloti periplasmic regulator protein exor adopts a superhelical fold and is controlled by a unique mechanism of proteolysis. | the sinorhizobium meliloti periplasmic exor protein and the exos/chvi two-component system form a regulatory mechanism that directly controls the transformation of free-living to host-invading cells. in the absence of crystal structures, understanding the molecular mechanism of interaction between exor and the exos sensor, which is believed to drive the key regulatory step in the invasion process, remains a major challenge. in this study, we present a theoretical structural model of the active f ... | 2014 | 25492513 |
| molecular modeling and computational analyses suggests that the sinorhizobium meliloti periplasmic regulator protein exor adopts a superhelical fold and is controlled by a unique mechanism of proteolysis. | the sinorhizobium meliloti periplasmic exor protein and the exos/chvi two-component system form a regulatory mechanism that directly controls the transformation of free-living to host-invading cells. in the absence of crystal structures, understanding the molecular mechanism of interaction between exor and the exos sensor, which is believed to drive the key regulatory step in the invasion process, remains a major challenge. in this study, we present a theoretical structural model of the active f ... | 2014 | 25492513 |