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proteomics of corynebacteria: from biotechnology workhorses to pathogens.corynebacteria belong to the high g+c gram-positive bacteria (actinobacteria) and are closely related to mycobacterium and nocardia species. the best investigated member of this group of almost seventy species is corynebacterium glutamicum, a soil bacterium isolated in 1957, which is used for the industrial production of more than two million tons of amino acids per year. this review focuses on the technical advances made in proteomics approaches during the last years and summarizes applications ...201121674800
genome-wide identification of in vivo binding sites of glxr, a cyclic amp receptor protein-type regulator in corynebacterium glutamicum.corynebacterium glutamicum glxr is a cyclic amp (camp) receptor protein-type regulator. although over 200 glxr-binding sites in the c. glutamicum genome are predicted in silico, studies on the physiological function of glxr have been hindered by the severe growth defects of a glxr mutant. this study identified the glxr regulon by chromatin immunoprecipitation in conjunction with microarray (chip-chip) analyses. in total, 209 regions were detected as in vivo glxr-binding sites. in vitro binding a ...201121665967
regulatory and metabolic networks for amino acid production by corynebacterium glutamicum. 201121664532
a guide through the computational analysis of isotope-labeled mass spectrometry-based quantitative proteomics data: an application study.abstract: background: mass spectrometry-based proteomics has reached a stage where it is possible to comprehensively analyze the whole proteome of a cell in one experiment. here, the employment of stable isotopes has become a standard technique to yield relative abundance values of proteins. in recent times, more and more experiments are conducted that depict not only a static image of the up- or down-regulated proteins at a distinct time point but instead compare developmental stages of an orga ...201121663690
characterization of the mannitol catabolic operon of corynebacterium glutamicum.corynebacterium glutamicum encodes a mannitol catabolic operon, which comprises three genes: the deor-type repressor coding gene mtlr (sucr), an mfs transporter gene (mtlt), and a mannitol 2-dehydrogenase gene (mtld). the mtlr gene is located upstream of the mtltd genes in the opposite orientation. in spite of this, wild-type c. glutamicum lacks the ability to utilize mannitol. this wild-type phenotype results from the genetic regulation of the genes coding for mannitol transport and catalytic p ...201121655984
monitoring enzyme expression of a branched respiratory chain of corynebacterium glutamicum using an egfp reporter gene.to investigate the expressional control of branched respiratory chain complexes of the amino-acid producing bacterium corynebacterium glutamicum according to growth conditions, the expression indexes of the ndh, sdh, qcrcab, ctacf, ctad, ctae, and cydab genes were estimated under aerobic and microaerobic, and carbon-rich and -poor conditions. the promoter region of each target gene was cloned upstream of the egfp gene on expression vector pvk6, and the nine reporter constructs were transformed i ...201121643696
identification of spia that interacts with corynebacterium glutamicum whca using two-hybrid system.the corynebacterium glutamicum whca gene is known to play a negative role in the expression of genes responding to oxidative stress. the encoded protein contains conserved cysteines, which likely coordinate the redox-sensitive fe-s cluster. to identify proteins which may interact with whca, we employed a two-hybrid system utilizing whca as a 'bait'. upon screening, several partner proteins were isolated from the c. glutamicum genomic library. sequencing analysis of the isolated clones revealed o ...201121623894
osmotic stress response in c. glutamicum: impact of channel- and transporter-mediated potassium accumulation.potassium accumulation is an essential aspect of bacterial response to diverse stress situations; consequently its uptake plays a pivotal role. here, we show that the gram-positive soil bacterium corynebacterium glutamicum which is employed for the large-scale industrial production of amino acids requires potassium under conditions of ionic and non-ionic osmotic stress. besides the accumulation of high concentrations of potassium contributing significantly to the osmotic potential of the cytopla ...201121614527
corynebacterium deserti sp. nov., isolated from desert in the west of china.a novel coryneform bacterium, was isolated from a sand sample collected in desert in the west of china. the strain comprised gram-positive, non-spore-forming, catalase-positive and irregular rods. comparative 16s rrna gene sequencing analysis demonstrated that the strain, gimn1.010(t), belonged to the genus corynebacterium and was closely related to c. glutamicum atcc 13032(t) (98.4%). however, dna relatedness between gimn1.010(t) and corynebacterium glutamicum was observed to be only 22.4±1.72% ...201121571935
kinetic characterisation of recombinant corynebacterium glutamicum nad(+)-dependent ldh over-expressed in e. coli and its rescue of an lldd (-) phenotype in c. glutamicum: the issue of reversibility re-examined.the ldh gene of corynebacterium glutamicum atcc 13032 (gene symbol cg3219, encoding a 314 residue nad(+)-dependent l: -(+)-lactate dehydrogenase, ec 1.1.1.27) was cloned into the expression vector pkk388-1 and over-expressed in an ldha-null e. coli tg1 strain upon isopropyl-β-d-thiogalactopyranoside (iptg) induction. the recombinant protein (referred to here as cgldh) was purified by a combination of dye-ligand and ion-exchange chromatography. though active in its absence, cgldh activity is enha ...201121567176
purification and characterization of an arginine regulatory protein, argr, in corynebacterium glutamicum.corynebacterium glutamicum, a gram-positive bacterium, has been widely used for industrial amino acid production. we previously showed that, in c. glutamicum, argcjbdfrgh arginine biosynthesis genes are clustered but independently transcribed from argc and argg promoters, leading to the generation of two transcripts corresponding to argcjbdfr and arggh. in this report, we show the effect of the c. glutamicum argr repressor on argc and argg promoters by overexpressing or disrupting the argr gene. ...201121559975
effects of l-(adamant-2-yl)glycyl-l-alanyl-d-isoglutamine on the antitumor action of cyclophosphamide, 5-fu, cisplatin and dacarbazine on advanced carcinomas of the mouse.a new biological response modifier, l-(adamant-2-yl)glycyl-l-alanyl-d-isoglutamine hydrochloride (adtp), recently synthesized and characterized for antitumor, antiviral and immunomodulating properties was studied in comparison to the peptidoglycan monomer (pgm) isolated from brevibacterium divaricatum to test the effects of their use concomitant to that of anticancer cytotoxic drugs such as cyclophosphamide, 5-fluorouracil (5-fu), cisplatin and 4-(3,3-dimethyl-1-triazeno)-5-carboxamide (dacarbaz ...199421559586
crystal structures of the transcriptional repressor rolr reveals a novel recognition mechanism between inducer and regulator.many members of the tetr family control the transcription of genes involved in multidrug resistance and pathogenicity. rolr (resorcinolregulator), the recently reported tetr-type regulator for aromatic catabolism from corynebacterium glutamicum, distinguishes itself by low sequence similarities and different regulation from the previously known members of the tetr family. here we report the crystal structures of rolr in its effector-bound (with resorcinol) and aop- forms at 2.5 å and 3.6 å, resp ...201121559286
biotechnological production of polyamines by bacteria: recent achievements and future perspectives.in bacteria, the pathways of polyamine biosynthesis start with the amino acids l: -lysine, l: -ornithine, l: -arginine, or l: -aspartic acid. some of these polyamines are of special interest due to their use in the production of engineering plastics (e.g., polyamides) or as curing agents in polymer applications. at present, the polyamines for industrial use are mainly synthesized on chemical routes. however, since a commercial market for polyamines as well as an industry for the fermentative pro ...201121552989
engineering bacillus subtilis for isobutanol production by heterologous ehrlich pathway construction and the biosynthetic 2-ketoisovalerate precursor pathway overexpression.in the present work, bacillus subtilis was engineered as the cell factory for isobutanol production due to its high tolerance to isobutanol. initially, an efficient heterologous ehrlich pathway controlled by the promoter p(43) was introduced into b. subtilis for the isobutanol biosynthesis. further, investigation of acetolactate synthase of b. subtilis, ketol-acid reductoisomerase, and dihydroxy-acid dehydratase of corynebacterium glutamicum responsible for 2-ketoisovalerate precursor biosynthes ...201121533914
co-evolutionary analysis enables rational deregulation of allosteric enzyme inhibition in corynebacterium glutamicum for lysine production.product feedback inhibition of allosteric enzymes is an essential issue for developing highly efficient microbial strains for bioproduction. here we use aspartokinase from corynebacterium glutamicum (cgak), a key enzyme controlling the biosynthesis of industrially important aspartate family amino acids, as a model to demonstrate a fast and efficient approach to deregulate allostery. in the last fifty years many researchers and companies have made considerable efforts to deregulate this enzyme fr ...201121531824
high yield secretion of heterologous proteins in corynebacterium glutamicum using its own tat-type signal sequence.efficient protein secretion, the basis of large-scale production of many compounds central to the biotechnology industry, is achieved by signal peptide and propeptide optimization in addition to optimizing host factors affecting heterologous protein production. here, we fused green fluorescent protein (gfp) to the recently identified tat-type secretory signal peptide of cgr0949 to demonstrate a high-yield protein secretion system of corynebacterium glutamicum. the resultant secretion vector faci ...201121523478
lipoarabinomannan and related glycoconjugates: structure, biogenesis and role in mycobacterium tuberculosis physiology and host-pathogen interaction.approximately one third of the world's population is infected with mycobacterium tuberculosis, the causative agent of tuberculosis. this bacterium has an unusual lipid-rich cell wall containing a vast repertoire of antigens, providing a hydrophobic impermeable barrier against chemical drugs, thus representing an attractive target for vaccine and drug development. apart from the mycolyl-arabinogalactan-peptidoglycan complex, mycobacteria possess several immunomodulatory constituents, notably lipo ...201121521247
tools for genetic manipulations in corynebacterium glutamicum and their applications.corynebacterium glutamicum is an important industrial producer of various amino acids with great potential for the production of other metabolites. the complete genome sequences of two c. glutamicum strains were determined and the use of genome-based approaches (transcriptomics, proteomics, metabolomics, and fluxomics) provided large amounts of data on the metabolism of this bacterium and its regulation. many tools for genetic manipulations in c. glutamicum have been developed and used for the a ...201121519933
investigation of phosphorylation status of odhi protein during penicillin- and tween 40-triggered glutamate overproduction by corynebacterium glutamicum.glutamate overproduction by corynebacterium glutamicum is triggered by treatment with penicillin or tween 40 and is accompanied by a decrease in 2-oxoglutarate dehydrogenase complex (odhc) activity. we have reported that de novo synthesis of odhi, which inhibits odhc activity by interacting specifically with the e1o subunit of odhc (odha), is induced by penicillin, and that odhi overexpression induces glutamate overproduction in the absence of any triggers for glutamate overproduction. in this s ...201121503757
phosphotransferase system-independent glucose utilization in corynebacterium glutamicum by inositol permeases and glucokinases.phosphoenolpyruvate-dependent glucose phosphorylation via the phosphotransferase system (pts) is the major path of glucose uptake in corynebacterium glutamicum, but some growth from glucose is retained in the absence of the pts. the growth defect of a deletion mutant lacking the general pts component hpr in glucose medium could be overcome by suppressor mutations leading to the high expression of inositol utilization genes or by the addition of inositol to the growth medium if a glucokinase is o ...201121478323
the ncgl1108 (phep (cg)) gene encodes a new l: -phe transporter in corynebacterium glutamicum.corynebacterium glutamicum played a central role in the establishment of fermentative production of amino acids, and it is a model for genetic and physiological studies. the general aromatic amino acid transporter, arop( cg ), was the sole functionally identified aromatic amino acid transporter from c. glutamicum. in this study, the ncgl1108 (named as phep ( cg )), which is located upstream of the genetic cluster (ncgl1110 ∼ ncgl1113) for resorcinol catabolism, was identified as a new l: -phe sp ...201121468701
identification and application of a different glucose uptake system that functions as an alternative to the phosphotransferase system in corynebacterium glutamicum.corynebacterium glutamicum uses the phosphoenolpyruvate-dependent sugar phosphotransferase system (pts) to uptake and phosphorylate glucose; no other route has yet been identified. disruption of the ptsh gene in wild-type c. glutamicum resulted, as expected, in a phenotype exhibiting little growth on any of the pts sugars: glucose, fructose, and sucrose. however, a suppressor mutant that grew on glucose but not on the other two sugars was spontaneously isolated from the pts-negative strain wt?pt ...201121452034
corynebacterium glutamicum tailored for efficient isobutanol production.we recently engineered corynebacterium glutamicum for aerobic production of 2-ketoisovalerate by inactivation of the pyruvate dehydrogenase complex, pyruvate:quinone oxidoreductase, transaminase b, and additional overexpression of the ilvbncd genes, encoding acetohydroxyacid synthase, acetohydroxyacid isomeroreductase, and dihydroxyacid dehydratase. based on this strain, we engineered c. glutamicum for the production of isobutanol from glucose under oxygen deprivation conditions by inactivation ...201121441331
lipoarabinomannan biosynthesis in corynebacterineae: the interplay of two +¦(1ôåæ2)-mannopyranosyltransferases mptc and mptd in mannan branching.lipomannan (lm) and lipoarabinomannan (lam) are key corynebacterineae glycoconjugates that are integral components of the mycobacterial cell wall, and are potent immunomodulators during infection. lam is a complex heteropolysaccharide synthesized by an array of essential glycosyltransferase family c (gt-c) members, which represent potential drug targets. herein, we have identified and characterized two open reading frames from corynebacterium glutamicum that encode for putative gt-cs. deletion o ...201121435038
metabolic engineering of 1,2-propanediol pathways in corynebacterium glutamicum.we analyzed 1,2-propanediol (1,2-pd) production in metabolically engineered corynebacterium glutamicum. wild-type c. glutamicum produced 93 µm 1,2-pd after 132 h incubation under aerobic conditions. no gene encoding the methylglyoxal synthase (mgs) which catalyzes the first step of 1,2-pd synthesis from the glycolytic pathway was detected on the c. glutamicum genome, but several genes annotated as encoding putative aldo-keto reductases (akrs) were present. akr functions as a methylglyoxal reduct ...201121424269
identification of succinate exporter in corynebacterium glutamicum and its physiological roles under anaerobic conditions.corynebacterium glutamicum produces succinate from glucose via the reductive tricarboxylic acid cycle under microaerobic and anaerobic conditions. we identified a ncgl2130 gene of c. glutamicum as a novel succinate exporter that functions in succinate production, and designated suce1. suce1 expression levels were higher under microaerobic conditions than aerobic conditions, and overexpression or disruption of suce1 respectively increased or decreased succinate productivity during fermentation. u ...201121420450
antimycobacterial activities of selected medicinal plants from zimbabwe against mycobacterium aurum and corynebacterium glutamicum.the spread of multi-drug resistant tuberculosis necessitates the discovery of new classes of antibacterials and compounds that inhibit macromolecules involved in these resistant mechanisms. thirty ethanol extracts from nineteen selected plants from zimbabwe were screened against mycobacterium aurum and corynebacterium glutamicum using the agar disk diffusion method. these two organisms were used as models for mycobacterium tuberculosis. the amount of ciprofloxacin accumulated and effluxed by the ...201021399602
mixed glucose and lactate uptake by corynebacterium glutamicum through metabolic engineering.the corynebacterium glutamicum atcc 13032 lysc(fbr) strain was engineered to grow fast on racemic mixtures of lactate and to secrete lysine during growth on lactate as well as on mixtures of lactate and glucose. the wild-type c. glutamicum only grows well on l-lactate. overexpression of d-lactate dehydrogenase (dld) achieved by exchanging the native promoter of the dld gene for the stronger promoter of the sod gene encoding superoxide dismutase in c. glutamicum resulted in a duplication of bioma ...201121370474
efficient markerless gene replacement in corynebacterium glutamicum using a new temperature-sensitive plasmid.random chemical mutation of a corynebacterium glutamicum-escherichia coli shuttle vector derived from plasmid pcgr2 was done using hydroxylamine. it brought about amino acid substitutions g109d and e180k within the replicase superfamily domain of the plasmid's repa protein and rendered the plasmid highly unstable, especially at higher incubation temperatures. colony formation of c. glutamicum was consequently completely inhibited at 37°c but not at 25°c. g109 is a semi-conserved residue mutation ...201121362445
exploring the conformational dynamics and membrane interactions of porb from c. glutamicum: a multi-scale molecular dynamics simulation study.members of the gram-positive mycolata bacteria have unusual cell envelopes which help them to avoid the immune system and the effects of most antibiotics, whilst rendering them permeable to solutes of importance in industrial bioconversion. it is therefore of interest to understand the molecular mechanisms for this selective permeability. porb is an unusual porin from the outer membrane (om) of corynebacterium glutamicum. it has been proposed as an atypical a-helical, symmetrical homo-pentameric ...201121354102
diversity of metabolic shift in response to oxygen deprivation in corynebacterium glutamicum and its close relatives.oxygen-deprived corynebacterium glutamicum r cells remain metabolically active, producing considerable amounts of organic acids even when not actively growing. we compared the proficiencies of c. glutamicum and close relatives grown under aerobic conditions to metabolize glucose when deprived of oxygen. eight strains that readily consumed glucose without cell growth subsequently produced organic acids. among these, the glucose consumption rates of the two c. glutamicum strains (>40 mm/h) and cor ...201121327408
microbial renewable feedstock utilization: a substrate-oriented approach.increasingly lignocellulosic biomass hydrolysates are used as the feedstock for industrial fermentations. these biomass hydrolysates consist of complex mixtures of different fermentable sugars, but also contain inhibitors and salts that affect the performance of the product-generating microbes. the performance of six industrially relevant microorganisms, i.e., two bacteria (escherichia coli and corynebacterium glutamicum), two yeasts (saccharomyces cerevisiae and pichia stipitis) and two fungi ( ...201021326838
control of adha and sucr expression by the sucr regulator in corynebacterium glutamicum.the alcohol dehydrogenase gene adha in corynebacterium glutamicum is subject to a complex carbon source-dependent regulation mediated by rama, ramb and glxr. in this study we identified sucr as the fourth transcriptional regulator involved in expression control of the adha gene. sucr specifically binds to the adha promoter and acts as transcriptional repressor independent of the carbon source used. furthermore, we found that sucr negatively controls the expression of its own gene. this negative ...201121320555
a new pathway for poly(3-hydroxybutyrate) production in escherichia coli and corynebacterium glutamicum by functional expression of a new acetoacetyl-coenzyme a synthase.a biosynthetic pathway for poly(3-hydroxybutyrate) [p(3hb)] was developed in escherichia coli and corynebacterium glutamicum by an acetoacetyl-coenzyme a (coa) synthase (aacs) recently isolated from terpenoid-producing streptomyces sp. strain cl190. expression of aacs led to significant productions of p(3hb) in e. coli (10.5 wt %) and c. glutamicum (19.7 wt %).201121307588
glutamate production from ß-glucan using endoglucanase-secreting corynebacterium glutamicum.we demonstrate glutamate production from ß-glucan using endoglucanase (eg)-expressing corynebacterium glutamicum. the signal sequence tora derived from escherichia coli k12, which belongs to the tat pathway, was suitable for secreting eg of clostridium thermocellum using c. glutamicum as a host. using the tora signal sequence, endoglucanase from clostridium cellulovorans 743b was successfully expressed, and the secreted eg produced 123 mg of reducing sugar from 5 g of ß-glucan at 30 °c for 72 h, ...201121305281
metabolic engineering of corynebacterium glutamicum for production of 1,5-diaminopentane from hemicellulose.in the present work, the bio-based production of 1,5-diaminopentane (cadaverine), an important building block for bio-polyamides, was extended to hemicellulose a non-food raw material. for this purpose, the metabolism of 1,5-diaminopentane-producing corynebacterium glutamicum was engineered to the use of the c(5) sugar xylose. this was realized by heterologous expression of the xyla and xylb genes from escherichia coli, mediating the conversion of xylose into xylulose 5-phosphate (an intermediat ...201121298810
impact of improved potassium accumulation on ph homeostasis, membrane potential adjustment and survival of corynebacterium glutamicum.metal ion uptake is crucial for all living cells and an essential part of cellular bioenergetic homeostasis. in this study the uptake and the impact of the most abundant internal cation, potassium, were investigated in actinobacteria, a group of high g+c gram-positives with a number of prominent biotechnologically and medically important members. genome analyses revealed a variety of different potassium uptake systems in this monophyletic group ranging from potassium channels common in virtually ...201121295539
structural asymmetry in a trimeric na+/betaine symporter, betp, from corynebacterium glutamicum.the na(+)-coupled symporter betp catalyzes the uptake of the compatible solute betaine in the soil bacterium corynebacterium glutamicum. betp also senses hyperosmotic stress and regulates its own activity in response to stress level. we determined a three-dimensional (3d) map (at 8 å in-plane resolution) of a constitutively active mutant of betp in a c. glutamicum membrane environment by electron cryomicroscopy of two-dimensional crystals. the map shows that the constitutively active mutant, whi ...201121281647
transcriptional regulators of multiple genes involved in carbon metabolism in corynebacterium glutamicum.corynebacterium glutamicum, a high-gc gram-positive soil bacterium, has been used in development of bioprocesses for production of various compounds such as amino acids, organic acids, and alcohols. recently, several transcriptional regulators, each of which is involved in multiple carbon metabolic pathways in this bacterium, have been identified and characterized. these regulators appear to form a complicated network mediating coordinated expression of a number of metabolic genes for efficient ...201121277916
sigma factors and promoters in corynebacterium glutamicum.the corynebacterium glutamicum genome codes for 7 sigma subunits (factors) of rna polymerase (rnap): primary sigma factor siga (s(a)), primary-like sigb and 5 other alternative sigma factors (sigc, sigd, sige, sigh and sigm). each sigma factor is responsible for recognizing promoters of genes belonging to a regulon (sigmulon) involved in specific functions of the cell. most promoters of c. glutamicum housekeeping genes are recognized by rnap+s(a), whereas s(b) is involved in transcription of a l ...201121277915
[corynebacterium pekinense transketolase: gene cloning, sequence analysis and expression].transketolase (ec 2. 2. 1. 1; tk) is the key enzyme in non-oxidative phosphate pentose pathway. we cloned tkt gene from corynebacterium pekinense as 1.299 and its mutant pd-67 in order to investigate the effect of gene expression on physiological characteristics of c. pekinense. pd-67.201021268892
corynebacterium glutamicum as a host for synthesis and export of d-amino acids.a number of d-amino acids occur in nature, and there is growing interest in their function and metabolism, as well as in their production and use. here we use the well-established l-amino-acid-producing bacterium corynebacterium glutamicum to study whether d-amino acid synthesis is possible and whether mechanisms for the export of these amino acids exist. in contrast to escherichia coli, c. glutamicum tolerates d-amino acids added extracellularly. expression of argr (encoding the broad-substrate ...201121257776
the effect of amtr on growth and amino acids production in corynebacterium glutamicum.amtr, the master regulator of nitrogen control in corynebacterium glutamicum, plays important roles in nitrogen metabolism. to investigate the influence of amtr on amino acids production in c. glutamicum atcc 13032, the amtr deletion strain c. glutamicum q1 was constructed and cultured in modified cgxii minimal medium for 60 h. the ammonium consumption rates as well as amino acids production of both strains cultured in modified cgxii minimal medium were determined. the amtr deletion in c. glutam ...201021254728
from zero to hero--design-based systems metabolic engineering of corynebacterium glutamicum for l-lysine production.here, we describe the development of a genetically defined strain of l-lysine hyperproducing corynebacterium glutamicum by systems metabolic engineering of the wild type. implementation of only 12 defined genome-based changes in genes encoding central metabolic enzymes redirected major carbon fluxes as desired towards the optimal pathway usage predicted by in silico modeling. the final engineered c. glutamicum strain was able to produce lysine with a high yield of 0.55 g per gram of glucose, a t ...201121241816
gene expression profiling of corynebacterium glutamicum during anaerobic nitrate respiration: induction of the sos response for cell survival.the gene expression profile of corynebacterium glutamicum under anaerobic nitrate respiration revealed marked differences in the expression levels of a number of genes involved in a variety of cellular functions, including carbon metabolism and respiratory electron transport chain, compared to the profile under aerobic conditions using dna microarrays. many sos genes were upregulated by the shift from aerobic to anaerobic nitrate respiration. an elongated cell morphology, similar to that induced ...201121239583
[metabolic flux analysis of l-serine synthesis by corynebacterium glutamicum syps-062].corynebacterium glutamicum syps-062 was an l-serine producing strain stored at our lab and could produce l-serine directly from sugar. we studied the effects of cofactors in one carbon unit metabolism-folate and vb12 on the cell growth, sucrose consumption and l-serine production by syps-062. in the same time, the metabolic flux distribution was determined in different conditions. the supplementation of folate or vb12 enhanced the cell growth, energy synthesis, and finally increased the flux of ...201021218623
control of heme homeostasis in corynebacterium glutamicum by the two-component system hrrsa.the response regulator hrra of the hrrsa two-component system (previously named cgtsr11) was recently found to be repressed by the global iron-dependent regulator dtxr in corynebacterium glutamicum. here, we provide evidence that hrra mediates heme-dependent gene regulation in this nonpathogenic soil bacterium. growth experiments and dna microarray analysis revealed that c. glutamicum is able to use hemin as an alternative iron source and emphasize the involvement of the putative hemin abc trans ...201121217007
assessment of bacterial diversity in the cattle tick rhipicephalus (boophilus) microplus through tag-encoded pyrosequencing.ticks are regarded as the most relevant vectors of disease-causing pathogens in domestic and wild animals. the cattle tick, rhipicephalus (boophilus) microplus, hinders livestock production in tropical and subtropical parts of the world where it is endemic. tick microbiomes remain largely unexplored. the objective of this study was to explore the r. microplus microbiome by applying the bacterial 16s tag-encoded flx-titanium amplicon pyrosequencing (btefap) technique to characterize its bacterial ...201121211038
mutational analysis of splicing activities of ribonucleotide reductase α subunit protein from lytic bacteriophage p1201.a cp1201 rir1 intein is found in the ribonucleotide reductase alpha subunit (rnr α subunit) protein of lytic bacteriophage p1201 from corynebacterium glutamicum nchu 87078. this intein can be over-expressed and spliced in escherichia coli novablue cells. mutations of c539, the n-terminal residue of the c-extein in the cp1201 rir1 protein, led to the changes of pattern and level of protein-splicing activities. a g392s variant was found to be a temperature-sensitive protein with complete splicing ...201121210121
enhancement of riboflavin production with bacillus subtilis by expression and site-directed mutagenesis of zwf and gnd gene from corynebacterium glutamicum.zwf (code for glucose-6-phosphate dehydrogenase) and gnd (code for 6-phosphogluconate dehydrogenase) genes from corynebacterium glutamicum were firstly cloned, and then site-directed mutagenesis was successfully introduced to remove allosteric inhibition by intracellular metabolites. expression of the mutant zwf and gnd in bacillus subtilis rh33 resulted in significant enhancement of riboflavin productivity, while the specific growth rate decreased slightly and the specific glucose uptake rate w ...201021194928
escherichia coli w as a new platform strain for the enhanced production of l-valine by systems metabolic engineering.a less frequently employed escherichia coli strain w, yet possessing useful metabolic characteristics such as less acetic acid production and high l-valine tolerance, was metabolically engineered for the production of l-valine. the ilva gene was deleted to make more pyruvate, a key precursor for l-valine, available for enhanced l-valine biosynthesis. the laci gene was deleted to allow constitutive expression of genes under the tac or trc promoter. the ilvbn(mut) genes encoding feedback-resistant ...201121191998
detection of d-ornithine extracellularly produced by corynebacterium glutamicum atcc 13032::argf.we found that corynebacterium glutamicum atcc 13032::argf extracellularly produced a large amount of d-ornithine when cultivated in a cgxii medium containing 1 mm l-arginine. this is the first report that c. glutamicum atcc 13032 or its mutant produces a d-amino acid extracellularly. c. glutamicum atcc 13032::argf produced 13 mm d-ornithine in 45 h of cultivation.201021187642
utilization of pei-modified corynebacterium glutamicum biomass for the recovery of pd(ii) in hydrochloric solution.a new type of biosorbent was developed for binding anionic precious metals through cross-linking waste biomass corynebacterium glutamicum with polyethylenimine (pei). this biomass was evaluated for the removal and recovery of palladium and compared to commercial adsorbents, such as amberjet 4200 cl, lewatit monoplus tp 214, spc-100, and sps-200. the kinetic experiments revealed that the sorption equilibrium was reached with 30 min for the pei-modified biomass. the maximum uptake of the biosorben ...201021185173
target genes, consensus binding site, and role of phosphorylation for the response regulator mtra of corynebacterium glutamicum.the two-component signal transduction system consisting of the sensor kinase mtrb and the response regulator mtra is highly conserved in corynebacteria and mycobacteria. whereas mtra of mycobacterium tuberculosis was reported to be essential, we recently succeeded in creating δmtrab and δmtra deletion mutants of corynebacterium glutamicum and provided evidence that mepa and nlpc, both encoding putative cell wall peptidases, are directly repressed by mtra, whereas prop and betp, both encoding car ...201021183673
escherichia coli exports cyclic amp via tolc.in escherichia coli more than 180 genes are regulated by the cyclic amp (camp)-camp receptor protein (crp) complex. however, more than 90% of camp that is made by intracellular adenylyl cyclases is found in the culture medium. how is camp exported from e. coli? in a tolc mutant, 0.03 mm iptg (isopropyl-β-d-thiogalactopyranoside) was sufficient to induce β-galactosidase compared to 0.1 mm iptg in the parent strain. in a cya mutant unable to produce camp about 1 mm extracellular camp was required ...201021183666
quinone-dependent d-lactate dehydrogenase dld (cg1027) is essential for growth of corynebacterium glutamicum on d-lactate.corynebacterium glutamicum is able to grow with lactate as sole or combined carbon and energy source. quinone-dependent l-lactate dehydrogenase lldd is known to be essential for utilization of l-lactate by c. glutamicum. d-lactate also serves as sole carbon source for c. glutamicum atcc 13032.201021159175
the protein encoded by ncgl1221 in corynebacterium glutamicum functions as a mechanosensitive channel.the function of the ncgl1221-encoded protein of corynebacterium glutamicum was analyzed using bacillus subtilis as host because a method for preparing the giant provacuole required for electrophysiological studies has been established. expression of ncgl1221 in a strain deficient in mscl and ykut, both of which encode mechanosensitive channels, resulted in an 8.9-fold higher cell survival rate upon osmotic downshock than the control. electrophysiological investigation showed that the giant prova ...201021150093
phenotypic characterization of corynebacterium glutamicum under osmotic stress conditions using elementary mode analysis.corynebacterium glutamicum, a soil bacterium, is used to produce amino acids such as lysine and glutamate. c. glutamicum is often exposed to osmolality changes in its medium, and the bacterium has therefore evolved several adaptive response mechanisms to overcome them. in this study we quantify the metabolic response of c. glutamicum under osmotic stress using elementary mode analysis (ema). further, we obtain the optimal phenotypic space for the synthesis of lysine and formation of biomass. the ...201021132515
identification of mannose uptake and catabolism genes in corynebacterium glutamicum and genetic engineering for simultaneous utilization of mannose and glucose.here, focus is on corynebacterium glutamicum mannose metabolic genes with the aim to improve this industrially important microorganism's ability to ferment mannose present in mixed sugar substrates. cgr_0857 encodes c. glutamicum's protein with 36% amino acid sequence identity to mannose 6-phosphate isomerase encoded by mana of escherichia coli. its deletion mutant did not grow on mannose and exhibited noticeably reduced growth on glucose as sole carbon sources. in effect, c. glutamicum mana is ...201021125267
interaction of transcriptional repressor argr with transcriptional regulator farr at the argb promoter region in corynebacterium glutamicum.in corynebacterium glutamicum, the argr protein, a transcriptional repressor, affects the expression level of the argb gene through binding to its promoter region. the argb promoter region (positions -77 to -25) has been found by in vitro electrophoretic mobility shift assay (emsa) results and in silico analysis to be important for the dna binding of argr. proline supplementation prevented the dna binding of argr to the argb promoter region and triggered an increase of the argb mrna level. addit ...201021115700
mycolic acid-containing bacteria induce natural-product biosynthesis in streptomyces species.natural products produced by microorganisms are important starting compounds for drug discovery. secondary metabolites, including antibiotics, have been isolated from different streptomyces species. the production of these metabolites depends on the culture conditions. therefore, the development of a new culture method can facilitate the discovery of new natural products. here, we show that mycolic acid-containing bacteria can influence the biosynthesis of cryptic natural products in streptomyce ...201021097597
translation efficiency of antiterminator proteins is a determinant for the difference in glucose repression of two β-glucoside phosphotransferase system gene clusters in corynebacterium glutamicum r.corynebacterium glutamicum r has two β-glucoside phosphoenolpyruvate, carbohydrate phosphotransferase systems (pts) encoded by bglf and bglf2 located in the respective clusters, bglf-bgla-bglg and bglf2-bgla2-bglg2. previously, we reported that whereas β-glucoside-dependent induction of bglf is strongly repressed by glucose, glucose repression of bglf2 is very weak. here, we reveal the mechanism behind the different effects of glucose on the two bgl genes. deletion of the ribonucleic antitermina ...201021075922
regulation of genes involved in sugar uptake, glycolysis and lactate production in corynebacterium glutamicum.corynebacterium glutamicum is a nonpathogenic, gc-rich, gram-positive bacterium with a long history in the industrial production of amino acids. recently, the species has become of increasing interest as a model bacterium for closely related, medically important pathogenic species such as corynebacterium diphtheriae and mycobacterium tuberculosis. in this article, recent advances in understanding of the c. glutamicum regulatory network of genes involved in carbohydrate metabolism are reviewed wi ...201021073308
determination of co₂ sensitivity of micro-organisms in shaken bioreactors. i. novel method based on the resistance of sterile closure.influence of carbon dioxide on growth and product kinetics of industrially important micro-organisms is essential for the interpretation of a bioprocess. in this research, the co₂ effects on productivity and growth rate of micro-organisms have been studied by using a variety of kplug. the applied method is based on a different concentration of co₂ in the headspace of ventilation flasks. the presented method is simple, inexpensive and shows similar results compared to large-scale fermentation reg ...201020973762
preparation of pei-coated bacterial biosorbent in water solution: optimization of manufacturing conditions using response surface methodology.the aim of this study is to optimize preparation method of polyethyleneimine (pei)-coated bacterial biosorbent in water as reaction media using fermentation waste biomass of corynebacterium glutamicum as a raw material. the fermentation waste biomass of c. glutamicum and reactive red 4 were used as model raw bacterium and pollutant. major factors affecting the performance of pei-coated biosorbent were the amounts of polymer (pei) and cross-linker glutaraldehyde (ga). these factors were optimized ...201020961751
the small ribosomal protein s12p gene rpsl as an efficient positive selection marker in allelic exchange mutation systems for corynebacterium glutamicum.we report that the mutant rpsl k43r in streptomycin-resistant and lysine-producing corynebacterium glutamicum is responsible for streptomycin resistance. in addition, we describe its effective application in gene modification in c. glutamicum.201020951172
metabolic engineering of corynebacterium glutamicum for 2-ketoisovalerate production.2-ketoisovalerate is used as a therapeutic agent, and a 2-ketoisovalerate-producing organism may serve as a platform for products deriving from this 2-keto acid. we engineered the wild type of corynebacterium glutamicum for the growth-decoupled production of 2-ketoisovalerate from glucose by deletion of the acee gene encoding the e1p subunit of the pyruvate dehydrogenase complex, deletion of the transaminase b gene ilve, and additional overexpression of the ilvbncd genes, encoding the l-valine b ...201020935122
leads for antitubercular compounds from kinase inhibitor library screens.discovering new drugs to treat tuberculosis more efficiently and to overcome multidrug resistance is a world health priority. to find antimycobacterial scaffolds, we screened a kinase inhibitor library of more than 12,000 compounds using an integrated strategy involving whole cell-based assays with corynebacterium glutamicum and mycobacterium tuberculosis, and a target-based assay with the protein kinase pkna. seventeen "hits" came from the whole cell-based screening approach, from which three d ...201020934382
the tetr-type transcriptional regulator fasr of corynebacterium glutamicum controls genes of lipid synthesis during growth on acetate.the addition of fatty acids to either escherichia coli or bacillus subtilis elicits an elaborate cellular response of the lipid metabolism. we found that in corynebacterium glutamicum the expression of accd1 encoding the β-subunit of the essential acetyl-coa carboxylase is repressed in acetate-grown cells without the addition of fatty acids. the tetr-type transcriptional regulator ncgl2404, termed fasr, was identified and deleted. during growth on acetate, but not on glucose, 17 genes are differ ...201020923423
the bcct family of carriers: from physiology to crystal structure.increases in the environmental osmolarity are key determinants for the growth of microorganisms. to ensure a physiologically acceptable level of cellular hydration and turgor at high osmolarity, many bacteria accumulate compatible solutes. osmotically controlled uptake systems allow the scavenging of these compounds from scarce environmental sources as effective osmoprotectants. a number of these systems belong to the bcct family (betaine-choline-carnitine-transporter), sodium- or proton-coupled ...201020923416
identification and quantification of mycothiol in actinobacteria by a novel enzymatic method.mycothiol (msh) was reported to be the dominant low molecular weight thiol in members of the actinobacteria. in this study, a simple, fast, and sensitive method for qualitative and quantitative determination of msh molecules was developed based on maleylpyruvate isomerase (mpi) from corynebacterium glutamicum. the principle of this method is that the activity of mpi from c. glutamicum was dependent on msh molecules. it was found that this mpi activity displayed a linear response (r (2) = 0.9928) ...201020922372
engineering of nitrogen metabolism and its regulation in corynebacterium glutamicum: influence on amino acid pools and production.nitrogen is one of the macronutrients necessary for living cells, and consequently, assimilation of nitrogen is a crucial step for metabolism. to satisfy their nitrogen demand and to ensure a sufficient nitrogen supply even in situations of nitrogen limitation, microorganisms have evolved sophisticated uptake and assimilation mechanisms for different nitrogen sources. this mini-review focuses on nitrogen metabolism and its control in the biotechnology workhorse corynebacterium glutamicum, which ...201020922371
regulation of the nitrate reductase operon narkghji by the camp-dependent regulator glxr in corynebacterium glutamicum.the corynebacterium glutamicum anaerobic nitrate reductase operon narkghji is repressed by a transcriptional regulator, arnr, under aerobic conditions. a consensus binding site of the camp receptor protein (crp)-type regulator, glxr, was recently found upstream of the arnr binding site in the nark promoter region. here we investigated the involvement of glxr and camp in expression of the narkghji operon in vivo. electrophoretic mobility shift assays showed that the putative glxr binding motif in ...201020864477
adaptation of amtr-controlled gene expression by modulation of amtr binding activity in corynebacterium glutamicum.in corynebacteria, nitrogen regulation is controlled by the tetr family protein amtr, which was extensively studied in the last years. in frame of these studies a number of amtr binding sites were identified and characterized and it became obvious that for distinct genes the number and sequences of these sites varied significantly. in this study, the influence of numbers and alterations of amtr binding sites were addressed by in vivo and in vitro studies. it can be concluded that in general a si ...201020854853
engineering of corynebacterium glutamicum with an nadph-generating glycolytic pathway for l-lysine production.a sufficient supply of nadph is a critical factor in l-lysine production by corynebacterium glutamicum. endogenous nad-dependent glyceraldehyde 3-phosphate dehydrogenase (gapdh) of c. glutamicum was replaced with nonphosphorylating nadp-dependent glyceraldehyde 3-phosphate dehydrogenase (gapn) of streptococcus mutans, which catalyzes the reaction of glyceraldehyde 3-phosphate to 3-phosphoglycerate with the reduction of nadp(+) to nadph, resulting in the reconstruction of the functional glycolyti ...201020851994
identification and characterization of a transcriptional regulator, sucr, that influences succd transcription in corynebacterium glutamicum.we have identified and characterized a novel transcriptional regulator that binds to the promoter region of succinyl-coa synthetase (succd) in corynebacterium glutamicum. using biotin-labeled dna affinity beads, we identified a deor-type transcriptional regulator, sucr (cg0146), which is a protein consisting of 282 amino acids with a mass of 31 kda and ramb (cg0444). the results of electrophoretic mobility shift assays verified that these regulators specifically bind to the succd promoter region ...201020851105
positive transcriptional control of the pyridoxal phosphate biosynthesis genes pdxst by the mocr-type regulator pdxr of corynebacterium glutamicum atcc 13032.the pdxr (cg0897) gene of corynebacterium glutamicum atcc 13032 encodes a regulatory protein belonging to the mocr subfamily of gntr-type transcription regulators and consisting of an amino-terminal winged helix-turn-helix dna-binding domain and a carboxy-terminal aminotransferase-like domain. a defined deletion in the pdxr gene resulted in the decreased expression of the divergently orientated pdxst genes coding for the subunits of pyridoxal 5'-phosphate synthase. the pdxst mutant c. glutamicum ...201120847010
acceptor substrate discrimination in phosphatidyl-myo-inositol mannoside synthesis: structural and mutational analysis of mannosyltransferase corynebacterium glutamicum pimb'.long term survival of the pathogen mycobacterium tuberculosis in humans is linked to the immunomodulatory potential of its complex cell wall glycolipids, which include the phosphatidylinositol mannoside (pim) series as well as the related lipomannan and lipoarabinomannan glycoconjugates. pim biosynthesis is initiated by a set of cytosolic α-mannosyltransferases, catalyzing glycosyl transfer from the activated saccharide donor gdp-α-d-mannopyranose to the acceptor phosphatidyl-myo-inositol (pi) i ...201020843801
enhanced production of l-arginine by expression of vitreoscilla hemoglobin using a novel expression system in corynebacterium crenatum.corynebacterium crenatum sypa 5-5 is an aerobic and industrial l: -arginine producer. it was proved that the corynebacterium glutamicum/escherichia coli shuttle vector pjc1 could be extended in c. crenatum efficiently when using the chloramphenicol acetyltransferase gene (cat) as a reporter under the control of promoter tac. the expression system was applied to over-express the gene vgb coding vitreoscilla hemoglobin (vhb) to further increase the dissolved oxygen in c. crenatum. as a result, the ...201120835781
the corynebacterium glutamicum aconitase repressor: scratching around for crystals.imperfections on the surfaces of crystallization containers are known to influence crystal formation and are thought to do so by helping to overcome the nucleation barrier. the intentional creation of imperfections has been widely applied to induce crystallization of small molecules, but has not been reported for protein crystallization. here, the crystallization and preliminary x-ray analysis of the tetr-type aconitase repressor are reported. this regulator was the first transcription factor to ...201020823530
autoinduction of a genetic locus encoding putative acyltransferase in corynebacterium glutamicum.a genetic locus, encoding putative acyltransferase, was induced by autoinducers in corynebacterium glutamicum. the autoinducers were maximally produced by the bacterium after 24 h culture. those molecules are resistant to proteinase k treatment (300 μg ml(-1)) for 30 min at 37°c or at 121°c for 15 min, and remained stable after extensive storage at 4°c. autoinducers in the cell-free culture fluids from corynebacterium ammoniagenes and pseudomonas aeruginosa also induced the expression of acyltra ...201120821248
corynebacterium glutamicum as an indicator for environmental cobalt and silver stress--a proteome analysis.cobalt and silver are toxic for cells, but mechanisms of this toxicity are largely unknown. analysis of corynebacterium glutamicum proteome from cells grown in control and cobalt or silver enriched media was performed by two dimensional gel electrophoresis (2de) followed by mass spectrometry. our results indicate that the cell adapted to cobalt stress by inducing five defense mechanisms: scavenging of free radicals, promotion of the generation of energy, reparation of dna, reparation and biogene ...201020818520
size exclusion chromatography-an improved method to harvest corynebacterium glutamicum cells for the analysis of cytosolic metabolites.the efficient separation of corynebacterium glutamicum cells from culture medium by size exclusion chromatography (sec) is presented. residue analysis demonstrated that this method effectively depletes extracellular compounds. for evaluation, sec was compared with the common methods cold methanol treatment, fast centrifugation and fast filtration. for this purpose, samples of c. glutamicum cells from fermenter cultures were harvested and subjected to a metabolome analysis. in particular, the wil ...201020817050
identification of the membrane protein suce and its role in succinate transport in corynebacterium glutamicum.succinic acid is excreted during anaerobiosis by many bacteria, and manifold applications are known making the biotechnological production of succinate attractive. although the pathways for succinate formation are known, succinate export is not understood in most of the succinate producing bacteria. here, we present a bioinformatic approach for identification of a putative succinate export system in corynebacterium glutamicum. the subsequent screening revealed that a mutant in the gene cg2425 is ...201120809072
purification and characterization of the ncgl2923 -encoded 3-hydroxybenzoate 6-hydroxylase from corynebacterium glutamicum.corynebacterium glutamicum atcc 13032 metabolizes 3-hydroxybenzoate via gentisate. we have now characterized the ncgl2923 -encoded 3-hydroxybenzoate 6-hydroxylase involved in the initial step of 3-hydroxybenzoate catabolism by this strain, a first 3-hydroxybenzoate 6-hydroxylase molecularly and biochemically characterized from a gram-positive strain. the ncg12923 gene from corynebacterium glutamicum atcc 13032 was shown to encode 3-hydroxybenzoate 6-hydroxylase, the enzyme that catalyzes the nad ...201020806251
link between phosphate starvation and glycogen metabolism in corynebacterium glutamicum, revealed by metabolomics.in this study, we analyzed the influence of phosphate (p(i)) limitation on the metabolism of corynebacterium glutamicum. metabolite analysis by gas chromatography-time-of-flight (gc-tof) mass spectrometry of cells cultivated in glucose minimal medium revealed a greatly increased maltose level under p(i) limitation. as maltose formation could be linked to glycogen metabolism, the cellular glycogen content was determined. unlike in cells grown under p(i) excess, the glycogen level in p(i)-limited ...201020802079
biosynthetic pathway for γ-cyclic sarcinaxanthin in micrococcus luteus: heterologous expression and evidence for diverse and multiple catalytic functions of c(50) carotenoid cyclases.we report the cloning and characterization of the biosynthetic gene cluster (crte, crtb, crti, crte2, crtyg, crtyh, and crtx) of the γ-cyclic c(50) carotenoid sarcinaxanthin in micrococcus luteus nctc2665. expression of the complete and partial gene cluster in escherichia coli hosts revealed that sarcinaxanthin biosynthesis from the precursor molecule farnesyl pyrophosphate (fpp) proceeds via c(40) lycopene, c(45) nonaflavuxanthin, c(50) flavuxanthin, and c(50) sarcinaxanthin. glucosylation of s ...201020802040
towards methionine overproduction in corynebacterium glutamicum--methanethiol and dimethyldisulfide as reduced sulfur sources.in the present work, methanethiol and dimethyldisulfide were investigated as sulfur source for methionine synthesis in corynebacterium glutamicum. in silico pathway analysis has predicted a high methionine yield for these reduced compounds provided that they can be utilized. wild type cells were able to grow on methanethiol and on dimethyldisulfide as sole sulfur source, respectively. isotope labeling studies with mutant strains exhibiting targeted modification of methionine biosynthesis gave de ...201020798582
antisense-rna-mediated plasmid copy number control in pcg1-family plasmids, pcgr2 and pcg1, in corynebacterium glutamicum.pcgr2 and pcg1 belong to different subfamilies of the pcg1 family of corynebacterium glutamicum plasmids. nonetheless, they harbour homologous putative antisense rna genes, crri and cgri, respectively. the genes in turn share identical positions complementary to the leader region of their respective repa (encoding plasmid replication initiator) genes. determination of their precise transcriptional start- and end-points revealed the presence of short antisense rna molecules (72 bp, crri; a ...201020798162
stacking multiple transgenes at a selected genomic site via repeated recombinase-mediated dna cassette exchanges.recombinase-mediated dna cassette exchange (rmce) has been successfully used to insert transgenes at previously characterized genomic sites in plants. following the same strategy, groups of transgenes can be stacked to the same site through multiple rounds of rmce. a gene-silencing cassette, designed to simultaneously silence soybean (glycine max) genes fatty acid ω-6 desaturase 2 (fad2) and acyl-acyl carrier protein thioesterase 2 (fatb) to improve oleic acid content, was first inserted by rmce ...201020720171
a role of the cspa gene encoding a mycolyltransferase in the growth under alkaline conditions of corynebacterium glutamicum.corynebacterium glutamicum is widely used in the industrial production of amino acids. producer strains are generated by classical random mutagenesis, and therefore have detrimental characteristics caused by unnecessary mutations. increased alkali sensitivity is one of those undesired characteristics. we found that one of the laboratory strains, aj12036deltacspadeltacspb, showed decreased growth under alkaline conditions. to clarify which mutation is responsible for alkali sensitivity, we constr ...201020699568
production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in recombinant corynebacterium glutamicum using propionate as a precursor.lipopolysaccharides free p[3-hydroxybutyrate (3hb)-co-3-hydroxyvalerate (3hv)] production was achieved using recombinant corynebacterium glutamicum harboring polyhydroxyalkanoate (pha) biosynthetic genes from ralstonia eutropha. cells grown on glucose with feeding of propionate as a precursor of 3hv unit accumulated 8-47wt% of p(3hb-co-3hv). the 3hv fraction in the copolymer was varied from 0 to 28mol% depending on the propionate concentrations.201120692303
crystal structures of the multidrug binding repressor corynebacteriumglutamicum cgmr in complex with inducers and with an operator.cgmr (cgl2612) from corynebacterium glutamicum is a multidrug-resistance-related transcription factor belonging to the tetr family, which is a protein family of widespread bacterial transcription factors typically involved in environmental response. here, we report the crystal structures of cgmr homodimeric repressor in complex with two distinct inducers (1.95 and 1.4 å resolution) and with an operator (2.5 å resolution). the cgmr-operator complex showed that two cgmr dimers bound to the operato ...201020691702
metabolic engineering of escherichia coli and corynebacterium glutamicum for the production of l-threonine.l-threonine is an essential amino acid for mammals and as such has a wide and expanding application in industry with a fast growing market demand. the major method of production of l-threonine is microbial fermentation. to optimize l-threonine production the fundamental solution is to develop robust microbial strains with high productivity and stability. metabolic engineering provides an effective alternative to the random mutation for strain development. in this review, the updated information ...201120688145
the e2 domain of odha of corynebacterium glutamicum has succinyltransferase activity dependent on lipoyl residues of the acetyltransferase acef.oxoglutarate dehydrogenase (odh) and pyruvate dehydrogenase (pdh) complexes catalyze key reactions in central metabolism, and in corynebacterium glutamicum there is indication of an unusual supercomplex consisting of acee (e1), acef (e2), and lpd (e3) together with odha. odha is a fusion protein of additional e1 and e2 domains, and odha orthologs are present in all corynebacterineae, including, for instance, mycobacterium tuberculosis. here we show that deletion of any of the individual domains ...201020675489
putrescine production by engineered corynebacterium glutamicum.here, we report the engineering of the industrially relevant corynebacterium glutamicum for putrescine production. c. glutamicum grew well in the presence of up to 500 mm of putrescine. a reduction of the growth rate by 34% and of biomass formation by 39% was observed at 750 mm of putrescine. c. glutamicum was enabled to produce putrescine by heterologous expression of genes encoding enzymes of the arginine- and ornithine decarboxylase pathways from escherichia coli. the results showed that the ...201020661733
corynebacterium glutamicum exhibits a membrane-related response to a small ferrocene-conjugated antimicrobial peptide.multiresistant bacteria are becoming more and more widespread. it is therefore necessary to have new compound groups in hand, such as small cationic peptides, to cope with these challenges. in this work, we present a comprehensive approach by monitoring protein expression profiles in a gram-positive bacterium (corynebacterium glutamicum) to investigate the cellular response to such a compound, a ferrocene-conjugated arginine- and tryptophan-rich pentapeptide. to achieve this, a proteomic outline ...201020658302
l-glutamine as a nitrogen source for corynebacterium glutamicum: derepression of the amtr regulon and implications for nitrogen sensing.corynebacterium glutamicum, a gram-positive soil bacterium employed in the industrial production of various amino acids, is able to use a number of different nitrogen sources, such as ammonium, urea or creatinine. this study shows that l-glutamine serves as an excellent nitrogen source for c. glutamicum and allows similar growth rates in glucose minimal medium to those in ammonium. a transcriptome comparison revealed that the nitrogen starvation response was elicited when glutamine served as the ...201020656783
tetrahydrolipstatin inhibition, functional analyses, and three-dimensional structure of a lipase essential for mycobacterial viability.the highly complex and unique mycobacterial cell wall is critical to the survival of mycobacteria in host cells. however, the biosynthetic pathways responsible for its synthesis are, in general, incompletely characterized. rv3802c from mycobacterium tuberculosis is a partially characterized phospholipase/thioesterase encoded within a genetic cluster dedicated to the synthesis of core structures of the mycobacterial cell wall, including mycolic acids and arabinogalactan. enzymatic assays performe ...201020656688
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