| two new members of the bio b superfamily: cloning, sequencing and expression of bio b genes of methylobacillus flagellatum and corynebacterium glutamicum. | cloning, characterization and expression of the bio b gene of the obligate methylotrophic bacterium, methylobacillus flagellatum, are reported. a chromosomal fragment containing bio b has been isolated by complementation of a bio b- mutant of m. flagellatum. nucleotide (nt) sequence analysis of this fragment revealed the presence of an open reading frame of 966 nt identified as bio b, which is the first gene of the m. flagellatum bio cluster. gene bio b was expressed in escherichia coli and m. f ... | 1996 | 8917070 |
| the gale gene encoding the udp-galactose 4-epimerase of brevibacterium lactofermentum is coupled transcriptionally to the dmdr gene. | the gale gene of brevibacterium lactofermentum, encoding udp-galactose 4-epimerase (ec 5.1.3.2), has been identified by dna sequencing downstream from the orf1-sigb-dmdr region. the arrangement of the sigb-dtxr-gale cluster is also conserved in corynebacterium diphtheriae. the deduced gale product was a protein of 329 aa residues (35.4 kda) that shared a high degree of identity to known udp-galactose 4-epimerase proteins from gram-positive microorganisms (streptomyces lividans and streptococcus ... | 1996 | 8921853 |
| construction of new cloning vectors for brevibacterium lactofermentum. | two plasmid cloning vectors (pulmj55 and pulmj95) were constructed for brevibacterium lactofermentum using the origin of replication of the endogenous plasmid pbl1. plasmid pulmj55 is a replacement vector with transcriptional terminators from the b. lactofermentum trp operon flanking the bglii cloning sites. religation of the bglii digested vector without insert creates a 376 bp perfect palindrome that is not tolerated in b. lactofermentum, giving positive selection for recombinant plasmids with ... | 1996 | 8935658 |
| codon usage in the mycobacterium tuberculosis complex. | the usage of alternative synonymous codons in mycobacterium tuberculosis (and m. bovis) genes has been investigated. this species is a member of the high-g+c gram-positive bacteria, with a genomic g+c content around 65 mol%. this g+c-richness is reflected in a strong bias towards c- and g-ending codons for every amino acid: overall, the g+c content at the third positions of codons is 83%. however, there is significant variation in codon usage patterns among genes, which appears to be associated ... | 1996 | 8936318 |
| a brevibacterium linens prbl1 replicon functional in corynebacterium glutamicum. | brevibacterium linens rbl strain cryptic plasmid prbl1 (8.0 kb) is described. a region involved in prbl1 autonomous replication in corynebacterium glutamicum was identified by insertion and deletion mapping and partially sequenced. this region encodes for a hypothetical 310-amino acid (aa) protein closely related to the replicases of plasmids pxz10142 (c. glutamicum) and pal5000 (mycobacterium fortuitum). the 310-aa protein also shows significant homology to proteins of pcole5-099 (shigella sonn ... | 1996 | 8938050 |
| a cryptic plasmid pbl1 from brevibacterium lactofermentum causes growth inhibition and filamentation in escherichia coli. | a shuttle vector composed of pbl1, a 4.46-kb cryptic plasmid from coryneform bacterium brevibacterium lactofermentum, and escherichia coli vector phsg298 was found to inhibit growth and cause cell filamentation in e coli. after construction of several deletions of pbl1, a 1.23-kb acci-hindiii fragment was found responsible. dna sequence analysis showed that this fragment contained a 726-bp-long open reading frame (orf3), encoding a protein with 242 amino acid residues. corresponding to orf3, a 2 ... | 1996 | 8938054 |
| cloning of the tryptophan operon of brevibacterium divaricatum and its expression in e. coli. | a genomic bank from brevibacterium divaricatum has been prepared using lambda embl3 as a vector. the genomic bank's titers are 2.2 x 10(6) pfu/micrograms. through screening by plaque hybridization, a 9.6 kb ncoi fragment which contains the entire trp operon has been isolated. polymerase chain reaction amplification and restriction endonuclease analysis of pcr fragments indicated that there is homology between the coryneform bacteria; however, some genetic diversity among the species still exists ... | 1996 | 8956524 |
| a new type of transporter with a new type of cellular function: l-lysine export from corynebacterium glutamicum. | we discovered that after deregulation of the l-lysine biosynthesis in corynebacterium glutamicum, l-lysine accumulated in the cytosol and the efflux properties of this amino acid in mutants used for l-lysine production were altered. in this study we describe the cloning and molecular identification of lyse, which encodes the translocator specifically exporting l-lysine from the cell. the lyse gene product does not display homology to any known transporter. it is only 236 amino acids in size, wit ... | 1996 | 8971704 |
| effects of altered phosphoenolpyruvate carboxylase activities on transgenic c3 plant solanum tuberosum. | phosphoenolpyruvate carboxylase (pepc) genes from corynebacterium glutamicum (cppc), escherichia coli (eppc) or flaveria trinervia (fppc) were transferred to solanum tuberosum. plant regenerants producing foreign pepc were identified by western blot analysis. maximum pepc activities measured in eppc and fppc plants grown in the greenhouse were doubled compared to control plants. for cppc a transgenic plant line could be selected which exhibited a fourfold increase in pepc activity. in the presen ... | 1996 | 8980535 |
| molecular cloning of a novel gene, dtsr, which rescues the detergent sensitivity of a mutant derived from brevibacterium lactofermentum. | several strains of corynebacterium and brevibacterium are known for their ability to secrete large amounts of amino acids, especially l-glutamate. we focused on the mechanism of l-glutamate secretion triggered by a detergent, namely polyoxyethylenesorbitan monopalmitate (pesp). a mutant strain, aj11060, derived from brevibacterium lactofermentum atcc 13869 indicates the sensitivity to pesp. a multicopy suppresser gene that compliments the sensitivity of aj11060 to the detergent was derived from ... | 1996 | 8987652 |
| molecular cloning of the corynebacterium glutamicum ('brevibacterium lactofermentum' aj12036) odha gene encoding a novel type of 2-oxoglutarate dehydrogenase. | the corynebacterium glutamicum ('brevibacterium lactofermentum' aj12036) odha gene, encoding 2-oxoglutarate dehydrogenase (e1o subunit of the 2-oxoglutarate dehydrogenase complex), has been isolated and identified as an homologous counterpart of the escherichia coll suca and bacillus subtilis odha genes. the nucleotide sequence of a 4394 bp chromosomal fragment containing the c. glutamicum odha gene was determined. the odha gene comprised 3771 bp (1257 codons, including the initiation codon) and ... | 1996 | 9004499 |
| construction of l-lysine-overproducing strains of brevibacterium lactofermentum by targeted disruption of the hom and thrb genes. | the mobilization of plasmids from gram-negative escherichia coli to gram-positive brevibacterium lactofermentum, mediated by p-type transfer functions, was used to construct disrupted mutants blocked specifically in the homoserine branch of the aspartate pathway. the mutant strain b. lactofermentum r31 showed an efficiency of conjugal transfer two to three orders of magnitude higher than that of the wild-type strain b. lactofermentum atcc 13869. the hom- and thrb-disrupted mutants of b. lactofer ... | 1996 | 9008889 |
| the s-layer protein of corynebacterium glutamicum is anchored to the cell wall by its c-terminal hydrophobic domain. | ps2 is the s-layer protein of corynebacterium glutamicum. the s-layer may be detached from the cell as organized sheets by detergents at room temperature. the solubilization of ps2 in the form of monomers requires detergent treatment at high temperature (70 degrees c), conditions under which the protein is denatured. treatment of the cells with proteinase k or trypsin results in the detachment of the organized s-layer, which remains organized. because we show that trypsin cleaves the c-terminal ... | 1997 | 9044282 |
| plasmid pga1 from corynebacterium glutamicum codes for a gene product that positively influences plasmid copy number. | the complete nucleotide sequence (4,826 bp) of the cryptic plasmid pga1 from corynebacterium glutamicum was determined. dna sequence analysis revealed four putative coding regions (open reading frame a [orfa], orfa2, orfb, and orfc). orfc was identified as a rep gene coding for an initiator of plasmid replication (rep) according to the high level of homology of its deduced amino acid sequence with the rep proteins of plasmids psr1 (from c. glutamicum) and png2 (from corynebacterium diphtheriae). ... | 1997 | 9045809 |
| accurate determination of 13c enrichments in nonprotonated carbon atoms of isotopically enriched amino acids by 1h nuclear magnetic resonance. | a method for the accurate determination of 13c enrichments in nonprotonated carbon atoms of organic compounds that makes use of unresolved 13c satellites of proton(s) bonded to the vicinal carbon atom was developed. using glutamate as a model molecule, this 1h nuclear magnetic resonance (nmr) inverse spin-echo difference spectroscopy method was calibrated for inversion efficiency and relaxation effects which were then shown to cause only a minor loss of the measured 13c satellite amplitude (2% f ... | 1997 | 9056211 |
| a corynebacterium glutamicum gene conferring multidrug resistance in the heterologous host escherichia coli. | a chromosomal dna fragment from the erythromycin-sensitive bacterium corynebacterium glutamicum atcc 13032 was shown to mediate resistance against erythromycin, tetracycline, puromycin, and bleomycin in escherichia coli. multicopy cloning of the fragment did not cause a resistance phenotype in c. glutamicum. the corresponding gene encodes a hydrophobic protein with 12 potential transmembrane-spanning ex-helical segments showing similarity to drug-h+ antiporters. | 1997 | 9079937 |
| a dtsr gene-disrupted mutant of brevibacterium lactofermentum requires fatty acids for growth and efficiently produces l-glutamate in the presence of an excess of biotin. | a dtsr gene encoding a homolog of the beta subunit of some biotin-containing enzymes suppresses a detergent-sensitive mutation of brevibacterium lactofermentum (e. kimura et al., 1996, biosci. biotech. biochem. 60, 1565-1570), which has been used for the fermentative production of l-glutamate. when the dtsr gene was disrupted, the organism exhibited strict fatty acid auxotrophy; oleate or oleate ester, but not palmitate ester or stearate ester, supported the growth of the delta dtsr mutant. immu ... | 1997 | 9168981 |
| isolation of the putp gene of corynebacterium glutamicum and characterization of a low-affinity uptake system for compatible solutes. | corynebacterium glutamicum accumulates the compatible solutes proline, glycine betaine, and ectoine under conditions of high osmolality. uptake of proline is mediated by both a high-affinity and a low-affinity secondary transport system. the low-affinity uptake system also accepts glycine betaine and ectoine as substrates. in the present study, the gene encoding the high-affinity proline uptake system putp was isolated by heterologous complementation of escherichia coli mutant strain wg389, whic ... | 1997 | 9238106 |
| transcriptional analysis of the siga and sigb genes of brevibacterium lactofermentum. | transcription of the siga and sigb genes of brevibacterium lactofermentum, encoding the principal sigma factors of rna polymerase, has been investigated by northern blot and primer extension analysis. northern hybridizations revealed that siga is transcribed as a monocistronic mrna of 1.7 kb and sigb gives two transcripts of 1.1 and 1.5 kb. similar transcription patterns of siga and sigb genes in nutrient-rich medium were observed; transcripts of both genes occurred simultaneously throughout the ... | 1997 | 9252580 |
| relationship between the glutamate production and the activity of 2-oxoglutarate dehydrogenase in brevibacterium lactofermentum. | enzyme activities of 2-oxoglutarate dehydrogenase complex and glutamate dehydrogenase of wild type brevibacterium lactofermentum, one of the typical glutamate-producing coryneform bacteria, were investigated by using cells cultured under glutamate-productive and glutamate-non-productive conditions. significant reduction of the former enzyme activity was observed in the cells under the several glutamate-productive conditions, namely, in the cells cultured in media containing a) limited concentrat ... | 1997 | 9255973 |
| efflux of compatible solutes in corynebacterium glutamicum mediated by osmoregulated channel activity. | bacteria respond to hypoosmotic stress by releasing low-molecular-mass solutes in order to maintain constant turgor pressure. we have studied the function of osmoregulated channel(s) in corynebacterium glutamicum, which are responsible for efflux of various solutes upon sudden decrease in osmotic pressure. the channels preferentially mediated efflux of compatible solutes such as glycine betaine and proline. the release of molecules of similar size, e.g. glutamate or lysine, was restricted, atp w ... | 1997 | 9266699 |
| molecular biology of s-layers. | in this chapter we report on the molecular biology of crystalline surface layers of different bacterial groups. the limited information indicates that there are many variations on a common theme. sequence variety, antigenic diversity, gene expression, rearrangements, influence of environmental factors and applied aspects are addressed. there is considerable variety in the s-layer composition, which was elucidated by sequence analysis of the corresponding genes. in corynebacterium glutamicum one ... | 1997 | 9276928 |
| regulation of acetate metabolism in corynebacterium glutamicum: transcriptional control of the isocitrate lyase and malate synthase genes. | in the amino-acid-producing microorganism corynebacterium glutamicum, the specific activities of the acetate-activating enzymes acetate kinase and phosphotransacetylase and those of the glyoxylate cycle enzymes isocitrate lyase and malate synthase were found to be high when the cells were grown on acetate (0.8, 2.9, 2.1, and 1.8 u/mg protein, respectively). when the cells were grown on glucose or on other carbon sources such as lactate, succinate, or glutamate, the specific activities were two- ... | 1997 | 9297462 |
| isolation of the corynebacterium glutamicum glna gene encoding glutamine synthetase i. | the corynebacterium glutamicum glutamine synthetase i (gsi) structural gene glna was cloned by a pcr approach using oligonucleotide primers derived from conserved amino acid sequences of the gsi proteins from various bacteria. disruption or deletion of this gene in c. glutamicum led to a glutamine auxotrophic phenotype and complete loss of glutamine synthetase activity, indicating the key role of this enzyme in nitrogen metabolism. additionally, indications for a second glutamine synthetase, gsi ... | 1997 | 9297824 |
| heterologous expression of the mycobacterium tuberculosis gene encoding antigen 85a in corynebacterium glutamicum. | by using appropriate corynebacterium glutamicum-escherichia coli shuttle plasmids, the gene encoding the fibronectin-binding protein 85a (85a) from mycobacterium tuberculosis was expressed in c. glutamicum, also an actinomycete and nonsporulating gram-positive rod bacterium, which is widely used in industrial amino acid production. the 85a gene was weakly expressed in c. glutamicum under the control of the ptac promoter from e. coli, but it was produced efficiently under the control of the promo ... | 1997 | 9361426 |
| sequence analysis of functional regions of homoserine dehydrogenase genes from l-lysine and l-threonine-producing mutants of brevibacterium lactofermentum. | the homoserine dehydrogenase (hd) genes from brevibacterium lactofermentum lysine- and threonine-producing mutants were cloned, using the polymerase chain reaction, and sequenced. we found the amino acid substitutions, val104ile in the lysine-producing mutants in which hd may cause leaky mutation and ser393phe in the threonine-producing mutant with feedback-insensitive hd. | 1997 | 9362124 |
| cloning, sequencing and expression of the gene encoding elongation factor p in the amino-acid producer brevibacterium lactofermentum (corynebacterium glutamicum atcc 13869). | the brevibacterium lactofermentum ef-p gene, encoding the elongation factor protein p, was cloned and sequenced. according to dna sequence analysis of this gene, the b. lactofermentum ef-p protein consists of 187 amino acids with a calculated molecular weight of 20,584. southern hybridization of an internal fragment of the ef-p gene from b. lactofermentum with chromosomal dnas from different microorganisms reveals that it is a unique gene product in b. lactofermentum and corynebacterium glutamic ... | 1997 | 9370284 |
| the corynebacterium glutamicum cglim gene encoding a 5-cytosine methyltransferase enzyme confers a specific dna methylation pattern in an mcrbc-deficient escherichia coli strain. | the cglim gene of the coryneform soil bacterium corynebacterium glutamicum atcc 13032 has been cloned and characterized. the coding region comprises 1092 nucleotides and specifies a protein of 363 amino acid residues with a deduced mr of 40700. the amino acid sequence showed striking similarities to methyltransferase enzymes generating 5-methylcytosine residues, especially to m x ngovii from neisseria gonorrhoeae recognizing the sequence gcsgc. the cglim gene is organized in an unusual operon wh ... | 1997 | 9426239 |
| the monovalent cation requirement of rabbit muscle pyruvate kinase is eliminated by substitution of lysine for glutamate 117. | the crystal structure of rabbit muscle pyruvate kinase complexed with mn2+, k+, and pyruvate revealed a binding site of k+ [t. m. larsen, l. t. laughlin, h. m. holden, i. rayment, and g. h. reed (1994) biochemistry 33, 6301-6309]. sequence comparisons of rabbit muscle pyruvate kinase and pyruvate kinases from corynebacterium glutamicum and escherichia coli, which do not exhibit a requirement for activation by monovalent cations, indicate that the only substitutions in the k+ binding site are con ... | 1997 | 9434737 |
| ultrastructure of the corynebacterium glutamicum cell wall. | the cell wall structure of the gram-positive corynebacterium glutamicum was evaluated by electron microscopy of thin sections after freeze-substitution and conventional fixation with glutaraldehyde. for the cell wall an overall thickness of approximately 32 nm was determined, with 8.5 nm corresponding to an outer layer, 6.5 nm to an electron translucent region (etr) as found in mycobacteria and 17 nm to the peptidoglycan. knob-like surface structures previously observed in freeze-fracture experi ... | 1997 | 9442270 |
| drug extrusion in corynebacterium glutamicum. | we selected a mutant of corynebacterium glutamicum, ebr, which can grow in a medium containing cytotoxic ethidium bromide (etbr) at a high concentration of 100 microm. the resistance to etbr in the mutant was reversed by 2 microm reserpine, a potent inhibitor of mammalian p-glycoprotein and bacterial multidrug resistance (mdr) transporter, whereas reserpine alone had a minimal effect on cell growth. the mutant showed a much higher efflux rate of etbr than wild-type cells, and the efflux was comp ... | 1997 | 9442486 |
| osmo-sensing by n- and c-terminal extensions of the glycine betaine uptake system betp of corynebacterium glutamicum. | the major uptake carrier for the compatible solute glycine betaine in corynebacterium glutamicum is the secondary transport system betp. it is effectively regulated by the external osmolality both on the level of expression and of activity. betp carries highly charged domains both at the n and at the c terminus. we investigated the role of these extensions in the regulatory response to hyperosmotic stress. mutants of the betp gene coding for proteins with truncated n- and c-terminal extensions w ... | 1998 | 9446558 |
| [the serological properties of saprophytic corynebacteria studied by immunoenzyme analysis]. | the degree of serological similarity of saprophytic corynebacteria have been studied using immunoassay elisa analysis, that is seven collection strains, belonging to corynebacterium glutamicum (3 strains), c. ammoniagenes (1 strain), c. vitarumen (1 strain), c. variabilis (2 strains) and three industrial strains-lysine producers. intact and heated bacteria cells have been used as antigens. it has been shown that industrial strain c. glutamicum 22l and collection strains c. glutamicum imv ac-715, ... | 1997 | 9480013 |
| improved l-lysine yield with corynebacterium glutamicum: use of dapa resulting in increased flux combined with growth limitation. | the amino acid l-lysine is produced on a large scale using mutants of corynebacterium glutamicum. however, as yet recombinant dna techniques have not succeed in improving strains selected for decades by classic mutagenesis for high productivity. we here report that seven biosynthetic enzymes were assayed and oversynthesis of the dihydrodipicolinate synthase resulted in an increase of lysine accumulation from 220 mm to 270 mm. the synthase, encoded by dapa, is located at the branch point of metab ... | 1998 | 9487706 |
| substrate and inhibitor binding sites in corynebacterium glutamicum diaminopimelate dehydrogenase. | the three-dimensional structures of corynebacterium glutamicum diaminopimelate dehydrogenase as a binary complex with the substrate meso-diaminopimelate (meso-dap) and a ternary complex with nadp+ and an isoxazoline inhibitor [abbot, s.d., lane-bell, p., kanwar, p.s.s., and vederas, j. c. (1994) j. am. chem. soc. 116, 6513-6520] have been solved and refined against x-ray diffraction data to 2.2 a. diaminopimelate dehydrogenase is a homodimer of approximately 35,000 molecular weight subunits and ... | 1998 | 9521647 |
| isoleucine uptake in corynebacterium glutamicum atcc 13032 is directed by the brnq gene product. | by complementation analysis of an isoleucine-uptake-deficient escherichia coli strain, it was shown that a 1.6-kb hindiii-stui fragment of corynebacterium glutamicum atcc 13032, located downstream of the aecd gene, encodes an isoleucine uptake system. sequence analysis revealed that the complementing fragment carried an open reading frame, termed brnq, that encodes a protein with sequence similarities to branched-chain amino acid carriers of gram-positive and gram-negative bacteria. the brnq gen ... | 1998 | 9531631 |
| effect of reversible reactions on isotope label redistribution--analysis of the pentose phosphate pathway. | the pentose phosphate pathway plays several key roles in metabolism including supply of biosynthetic carbon skeletons and reducing power. previous research has focused on determining the fluxes through the reactions of this pathway using carbon-labeled substrates and models that make certain assumptions about the reversibility of the transketolase and transaldolase reactions in the nonoxidative pathway. these assumptions, however, have resulted in inconsistencies between the predicted carbon lab ... | 1998 | 9546650 |
| urea uptake and urease activity in corynebacterium glutamicum. | when corynebacterium glutamicum is grown with a sufficient nitrogen supply, urea crosses the cytoplasmic membrane by passive diffusion. a permeability coefficient for urea diffusion of 9 x 10(-7) cm s-1 was determined. under conditions of nitrogen starvation, an energy-dependent urea uptake system was synthesized. carrier-mediated urea transport was catalyzed by a secondary transport system linked with proton motive force. with a km for urea of 9 microm, the affinity of this uptake system was mu ... | 1998 | 9560422 |
| pyruvate carboxylase from corynebacterium glutamicum: characterization, expression and inactivation of the pyc gene. | in addition to phosphoenolpyruvate carboxylase (pepcx), pyruvate carboxylase (pcx) has recently been found as an anaplerotic enzyme in the amino-acid-producing bacterium corynebacterium glutamicum. using oligonucleotides designed according to conserved regions of pcx amino acid sequences from other organisms, a 200 bp fragment central to the c. glutamicum pcx gene (pyc) was amplified from genomic dna by pcr. this fragment was then used to identify and to subclone the entire c. glutamicum pyc gen ... | 1998 | 9579065 |
| [construction and characteristics of a cosmid library of genes of the bacterium cornyebacterium glutamicum atss13032]. | a representative genomic library of the corynebacterium glutamicum atcc 13032 genes in a cosmid vector lorist6 was created. the cosmids contain inserts of bacterial dna obtained by partial digestion with the sau3a i restrictase. five hundred and thirty individual primary recombinant clones were transferred into the wells of microtiter plates, where they are now being preserved. the average size of the bacterial dna inserts determined via a sum of restriction fragment sizes of recombinant molecul ... | 1998 | 9589870 |
| ppc, the gene for phosphoenolpyruvate carboxylase from an extremely thermophilic bacterium, rhodothermus obamensis: cloning, sequencing and overexpression in escherichia coli. | the ppc gene, which encodes phosphoenolpyruvate carboxylase (pepc) of an extremely thermophilic bacterium, rhodothermus obamensis, was directly sequenced by the thermal asymmetric interlaced (tail) pcr method. an orf for a 937 amino acid polypeptide was found in the gene. the ppc gene had a high g+c content (66.2 mol%) and the third position of the codon exhibited strong preference for g or c usage (85.0 mol%). the calculated molecular mass was 107,848 da, which was consistent with the molecular ... | 1998 | 9611816 |
| different modes of diaminopimelate synthesis and their role in cell wall integrity: a study with corynebacterium glutamicum. | in eubacteria, there are three slightly different pathways for the synthesis of m-diaminopimelate (m-dap), which is one of the key linking units of peptidoglycan. surprisingly, for unknown reasons, some bacteria use two of these pathways together. an example is corynebacterium glutamicum, which uses both the succinylase and dehydrogenase pathways for m-dap synthesis. in this study, we clone dapd and prove by enzyme experiments that this gene encodes the succinylase (m(r) = 24082), initiating the ... | 1998 | 9620966 |
| new shuttle vectors for rhodococcus sp. r312 (formerly brevibacterium sp. r312), a nitrile hydratase producing strain. | two shuttle vectors named prc52 (10.7 kb) and prk52 (12.2 kb) carrying chloramphenicol (cm) and chloramphenicol plus kanamycin (km) resistance genes, respectively, were constructed by fusion of a cryptic plasmid pbl13869 (replicon pbl1, 5.8 kb) from brevibacterium lactofermentum atcc13869 with pbr328 e. coli plasmid. transformation of rhodococcus sp. r312 (formerly brevibacterium sp. r312) protoplasts was realised with an efficiency of 28 transformants per micrograms of dna. | 1998 | 9637010 |
| cloning of the histidine biosynthetic genes of corynebacterium glutamicum: organization and sequencing analysis of the hisa, impa, and hisf gene cluster. | the hisa and hisf genes of corynebacterium glutamicum were cloned by transforming histidine auxotrophic escherichia coli with the genomic dna library. they are two of the eight genes that participate in the histidine biosynthetic pathway. cloned dna fragments containing the genes can also complement hish and hisi auxotrophs of escherichia coli, suggesting that the four genes are clustered in the genome. we determined the nucleotide sequences of the minimal fragment containing the hisa and hisf g ... | 1998 | 9647764 |
| carbon-flux distribution in the central metabolic pathways of corynebacterium glutamicum during growth on fructose. | growth of corynebacterium glutamicum on fructose was significantly less than that obtained on glucose, despite similar rates of substrate uptake. this was in part due to the production of overflow metabolites (dihydroxyacetone and lactate) but also to the increased production of co2 during growth on fructose. these differences in carbon-metabolite accumulation are indicative of a different pattern of carbon-flux distribution through the central metabolic pathways. growth on glucose has been prev ... | 1998 | 9652400 |
| biochemical and genetic characterization of the membrane-associated malate dehydrogenase (acceptor) from corynebacterium glutamicum. | in addition to a cytoplasmic, nad-dependent malate dehydrogenase (ec 1.1.1.37), corynebacterium glutamicum possesses a highly active membrane-associated malate dehydrogenase (acceptor) (ec 1.1.99.16). this enzyme also takes part in the citric acid cycle. it oxidizes l-malate to oxaloacetate and donates electrons to ubiquinone-1 and other artificial acceptors or, via the electron transfer chain, to oxygen. nad is not an acceptor and the natural direct acceptor for the enzyme is most likely a quin ... | 1998 | 9660197 |
| cloning and characterization of 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) transferase genes (kdta) from acinetobacter baumannii and acinetobacter haemolyticus. | 3-deoxy-d-manno-oct-2-ulosonic acid (kdo) transferases (kdta) are multifunctional glycosyltransferases with primary structures of low similarity. totally degenerated primers were deduced from two stretches of identical amino acids between known kdta sequences and used to amplify by pcr a kdta-specific fragment from acinetobacter baumannii atcc 15308 dna which was then applied as a probe for the cloning and sequencing of the complete kdo transferase gene. with conserved pcr primers for this struc ... | 1998 | 9660198 |
| isolation and analysis of meta, a methionine biosynthetic gene encoding homoserine acetyltransferase in corynebacterium glutamicum. | the meta gene encoding homoserine acetyltransferase, the first enzyme of the methionine biosynthetic pathway, was isolated from a pmt1-based corynebacterium glutamicum gene library via complementation of an escherichia coli meta mutant. a dna-sequence analysis of the cloned dna is identified an open-reading frame of 1,137 bp which encodes a protein with the molecular weight of 41,380 comprising 379 amino acids. the putative protein product showed good amino acid-sequence homology to its counterp ... | 1998 | 9666465 |
| a bacterial cytokine. | viable cells of micrococcus luteus secrete a factor, which promotes the resuscitation and growth of dormant, nongrowing cells of the same organism. the resuscitation-promoting factor (rpf) is a protein, which has been purified to homogeneity. in picomolar concentrations, it increases the viable cell count of dormant m. luteus cultures at least 100-fold and can also stimulate the growth of viable cells. rpf also stimulates the growth of several other high g+c gram-positive organisms, including my ... | 1998 | 9671779 |
| the role of the corynebacterium glutamicum rel gene in (p)ppgpp metabolism. | to investigate the metabolism of (p)ppgpp in amino-acid-producing coryneform bacteria, a pcr-based strategy using degenerate consensus oligonucleotides was applied to isolate the rel gene of corynebacterium glutamicum atcc 13032. the gene consists of 2283 nucleotides and encodes a protein of 760 amino acids with a molecular mass of 84.4 kda. the amino acid sequence revealed extensive similarities to the related proteins rela and spot of escherichia coli, which are known to be involved in (p)ppgp ... | 1998 | 9695918 |
| a novel system with positive selection for the chromosomal integration of replicative plasmid dna in corynebacterium glutamicum. | a simple system has been developed for generating corynebacterium glutamicum strains containing stable replicative plasmids integrated into the chromosome via homologous recombination. the system is based upon extremely strong incompatibility between two plasmids, which cannot be co-maintained even under antibiotic selective pressure. integration of the resident plasmid that contained the trpd gene of c. glutamicum was achieved by introduction of a second plasmid and subsequent selection for the ... | 1998 | 9695919 |
| analysis of the leub gene from corynebacterium glutamicum. | the leub gene of corynebacterium glutamicum was found to be present on a 2.2-kb bamhi-saci chromosomal fragment which complemented the leub mutation of escherichia coli. the activity of 3-isopropylmalate dehydrogenase (ec 1.1.1.85), encoded by the leub gene, was significantly increased in c. glutamicum cells harbouring a plasmid containing the 2.2-kb fragment. the nucleotide sequence of the c. glutamicum leub coding region (an open reading frame, orf, of 1020 bp encoding a polypeptide of 340 ami ... | 1998 | 9720199 |
| corynebacterium striatum chloramphenicol resistance transposon tn5564: genetic organization and transposition in corynebacterium glutamicum. | the clinical isolate corynebacterium striatum m82b (formerly corynebacterium xerosis m82b) carries the 50-kb r-plasmid ptp10 conferring resistance to the antibiotics chloramphenicol, erythromycin, kanamycin, and tetracycline. dna sequence analysis of the chloramphenicol resistance region revealed the presence of the 4155-bp transposable element tn5564. the ends of tn5564 are identical 22-bp inverted repeats flanked by a 6-bp target site duplication. the central region of tn5564 encodes the chlor ... | 1998 | 9735314 |
| identification, characterization, and chromosomal organization of the ftsz gene from brevibacterium lactofermentum. | the ftsz gene was cloned from the chromosomal dna of brevibacterium lactofermentum by the polymerase chain reaction (pcr) using two oligonucleotides designed from two conserved regions found in most of the previously cloned and sequenced ftsz genes from other microorganisms. ftsz is a single-copy gene in corynebacteria and is located downstream from ftsq and murc, indicating linkage between genes involved in peptidoglycan synthesis (mur genes) and genes involved in cell division (fts genes). the ... | 1998 | 9738885 |
| biochemical and biophysical characterization of the cell wall porin of corynebacterium glutamicum: the channel is formed by a low molecular mass polypeptide. | the cell wall of the gram-positive bacterium corynebacterium glutamicum contains a channel (porin) for the passage of hydrophilic solutes. the channel-forming protein was identified, by lipid bilayer experiments, in the cell envelope fractions isolated by sucrose-density centrifugations and in organic solvent of whole cells. it was purified to homogeneity by fast-protein liquid chromatography across a mono-q column. the pure protein had a rather low molecular mass of about 5 kda as judged by sds ... | 1998 | 9790664 |
| sequence of the corynebacterium glutamicum pyruvate carboxylase gene. | pyruvate carboxylase is an important anaplerotic enzyme replenishing oxaloacetate consumed for biosynthesis during growth, or lysine and glutamic acid production in industrial fermentations. we used regions of homology from pyruvate carboxylase sequences of 12 different species (corresponding to the atp- and pyruvate-binding sites), to design polymerase chain reaction (pcr) primers for amplifying a fragment of the pyruvate carboxylase (pc) gene from c. glutamicum genomic dna. this 850-base-pair ... | 1998 | 9802220 |
| corynebacterium glutamicum is equipped with four secondary carriers for compatible solutes: identification, sequencing, and characterization of the proline/ectoine uptake system, prop, and the ectoine/proline/glycine betaine carrier, ectp. | gram-positive soil bacterium corynebacterium glutamicum uses the compatible solutes glycine betaine, proline, and ectoine for protection against hyperosmotic shock. osmoregulated glycine betaine carrier betp and proline permease putp have been previously characterized; we have identified and characterized two additional osmoregulated secondary transporters for compatible solutes in c. glutamicum, namely, the proline/ectoine carrier, prop, and the ectoine/glycine betaine/proline carrier, ectp. a ... | 1998 | 9811661 |
| molecular cloning and analysis of the argc gene from corynebacterium glutamicum. | the argc gene encoding n-acetylglutamate 5-semialdehyde dehydrogenase has been cloned from corynebacterium glutamicum by transforming escherichia coli arginine auxotroph with the genomic dna library. based on the restriction map of the cloned dna, we have subcloned and sequenced the minimal dna fragment complementing the e. coli argc mutant. the coding region of the cloned gene is 1041 nucleotides long with a predicted molecular mass of about 38 kda polypeptide. enzyme activity and size of the e ... | 1998 | 9818083 |
| an integron of class 1 is present on the plasmid pcg4 from gram-positive bacterium corynebacterium glutamicum. | the streptomycin/spectinomycin resistance determinant of the 29-kb plasmid pcg4 from corynebacterium glutamicum was found to be a part of a typical class 1 integron. the sequence analysis revealed that the integron (designated incg) identified in this gram-positive bacterium is almost identical to the integron inc present on the plasmid psa1700 from the gram-negative bacterium pseudomonas aeruginosa. differences in only two base pairs were found in the 3.8-kb sequence. one base substitution (g-- ... | 1998 | 9868786 |
| characterization of a facultatively psychrophilic bacterium, vibrio rumoiensis sp. nov., that exhibits high catalase activity | a novel facultatively psychrophilic bacterium, strain s-1, which exhibits extraordinarily high catalase activity was isolated from the drain pool of a fish product processing plant that uses h2o2 as a bleaching and microbicidal agent. the catalase activity of the isolate was 1 or 2 orders of magnitude higher than those of corynebacterium glutamicum, staphylococcus aureus, pseudomonas fluorescens, and five other species tested in this study. the strain seemed to possess only one kind of catalase, ... | 1999 | 9872761 |
| mapping and identification of corynebacterium glutamicum proteins by two-dimensional gel electrophoresis and microsequencing. | as a prerequisite for proteome analyses of corynebacterium glutamicum separation of the cytoplasm and the membrane fraction was optimized and two-dimensional (2-d) gel electrophoresis was established. the resulting 2-d protein maps revealed over 1000 silver-stained protein spots separated by isoelectric point and molecular mass for cytoplasmic proteins and approximately 700 silver-stained spots for proteins of the membrane fraction. proposing a mean size of 1 kbp per gene the complete c. glutami ... | 1998 | 9932818 |
| identification of mechanosensitive ion channels in the cytoplasmic membrane of corynebacterium glutamicum. | patch-clamp experiments performed on membrane fragments of corynebacterium glutamicum fused into giant liposomes revealed the presence of two different stretch-activated conductances, 600 to 700 ps and 1,200 to 1,400 ps in 0.1 m kcl, that exhibited the same characteristics in terms of kinetics, ion selectivity, and voltage dependence. | 1999 | 10049402 |
| analysis of the integration functions of phi304l: an integrase module among corynephages. | plasmid p12929 was shown to integrate into the chromosome of corynebacterium glutamicum rm3 and bl15. the minimal integrating fragment was subsequently defined. the arms flanking the integrated plasmid (attl and attr) were identified, allowing for the determination of the attp and the attb attachment sites. the attb site is located at the 3' end of an orf presenting 62-78% identity with l19 ribosomal proteins. integration in the attb site does not result in the inactivation of this gene because ... | 1999 | 10049830 |
| in vivo fluxes in the ammonium-assimilatory pathways in corynebacterium glutamicum studied by 15n nuclear magnetic resonance | glutamate dehydrogenase (gdh) and glutamine synthetase (gs)-glutamine 2-oxoglutarate-aminotransferase (gogat) represent the two main pathways of ammonium assimilation in corynebacterium glutamicum. in this study, the ammonium assimilating fluxes in vivo in the wild-type atcc 13032 strain and its gdh mutant were quantitated in continuous cultures. to do this, the incorporation of 15n label from [15n]ammonium in glutamate and glutamine was monitored with a time resolution of about 10 min with in v ... | 1999 | 10049869 |
| cloning, sequence analysis, expression and inactivation of the corynebacterium glutamicum pta-ack operon encoding phosphotransacetylase and acetate kinase. | the corynebacterium glutamicum ack and pta genes encoding the acetate-activating enzymes acetate kinase and phosphotransacetylase were isolated, subcloned on a plasmid and re-introduced into corynebacterium glutamicum. relative to the wild-type, the recombinant strains showed about tenfold higher specific activities of both enzymes. sequence analysis of a 3657 bp dna fragment revealed that the ack and pta genes are contiguous in the corynebacterial chromosome, with pta upstream and the last nucl ... | 1999 | 10075432 |
| cloning of the transketolase gene and the effect of its dosage on aromatic amino acid production in corynebacterium glutamicum. | transketolase is a key enzyme of the non-oxidative pentose phosphate pathway. the effect of its overexpression on aromatic amino acid production was investigated in corynebacterium glutamicum, a typical amino-acid-producing organism. for this purpose, the transketolase gene of the organism was cloned on the basis of its ability to complement a c. glutamicum transketolase mutant with pleiotropically shikimic-acid-requiring, ribose- and gluconic-acid-negative phenotype. the gene was shown by delet ... | 1999 | 10091326 |
| purification and stabilization of a monomeric isocitrate dehydrogenase from corynebacterium glutamicum. | monomeric isocitrate dehydrogenase was expressed in corynebacterium glutamicum cells harboring pek-icdes1, a plasmid carrying the gene for the enzyme. two- to three-fold higher expression levels of the recombinant enzyme were observed in such cells when grown in fermentors, compared to those grown in shaker incubators. the enzyme was purified to homogeneity by ammonium sulfate fractionation, sephadex g-150 gel filtration, fplc mono q anion-exchange chromatography, and affinity gel chromatography ... | 1999 | 10092494 |
| expression of the corynebacterium glutamicum pand gene encoding l-aspartate-alpha-decarboxylase leads to pantothenate overproduction in escherichia coli. | the corynebacterium glutamicum pand gene was identified by functional complementation of an escherichia coli pand mutant strain. sequence analysis revealed that the coding region of pand comprises 411 bp and specifies a protein of 136 amino acid residues with a deduced molecular mass of 14.1 kda. a defined c. glutamicum pand mutant completely lacked l-aspartate-alpha-decarboxylase activity and exhibited beta-alanine auxotrophy. the c. glutamicum pand (pandc. g.) as well as the e. coli pand (pand ... | 1999 | 10103247 |
| experimental determination of group flux control coefficients in metabolic networks | grouping of reactions around key metabolite branch points can facilitate the study of metabolic control of complex metabolic networks. this top-down metabolic control analysis is exemplified through the introduction of group (flux, as well as concentration) control coefficients whose magnitudes provide a measure of the relative impact of each reaction group on the overall network flux, as well as on the overall network stability, following enzymatic amplification. in this article, we demonstrate ... | 1998 | 10191384 |
| site-specific integration of corynephage phi16: construction of an integration vector. | phi16, a temperate phage induced from corynebacterium glutamicum atcc 21792, lysogenizes its host via site-specific recombination. the phage attachment site, attp, was located to a 6.5 kb bamhi fragment of the phi16 genome. this fragment also contained phi16 integrative functions. the minimal phage dna fragment required for integration was defined. this 1630 bp region contained a large open reading frame, int, encoding a protein of 416 amino acids with similarity in its carboxyl-terminal domain ... | 1999 | 10217487 |
| structure and organization of the rrnd operon of 'brevibacterium lactofermentum': analysis of the 16s rrna gene. | five rrna operons (rrn) were found by hybridization in the genome of 'brevibacterium lactofermentum' atcc 13869 and corynebacterium glutamicum atcc 13032. 'b. lactofermentum' dsm 20412 differed from the other corynebacteria tested in showing six hybridizing bamhi bands. two of the rrn operons (rrnd and rrne) were located in a single cosmid. sequencing of the rrnd operon showed that it contains a complete 16s rrna-23s rna-5s rrna gene cluster. phylogenetic studies using the complete 16s rrna sequ ... | 1999 | 10220171 |
| the tetab genes of the corynebacterium striatum r-plasmid ptp10 encode an abc transporter and confer tetracycline, oxytetracycline and oxacillin resistance in corynebacterium glutamicum. | the tetracycline resistance region of the 50-kb r-plasmid ptp10 from the clinical isolate corynebacterium striatum m82b was analyzed in corynebacterium glutamicum atcc 13032 and confined to a 4.4-kb sphi-sa/i dna fragment. nucleotide sequence analysis revealed two open reading frames, termed teta and tetb, specifying proteins of 513 and 528 amino acids, respectively. the deduced amino acid sequences of tetab displayed similarity to atp-binding cassette transporters including strv and strw of str ... | 1999 | 10220896 |
| flux through the tetrahydrodipicolinate succinylase pathway is dispensable for l-lysine production in corynebacterium glutamicum. | the n-succinyl-ll-diaminopimelate desuccinylase gene (dape) in the four-step succinylase branch of the l-lysine biosynthetic pathway of corynebacterium glutamicum was disrupted via marker-exchange mutagenesis to create a mutant strain that uses only the one-step meso-diaminopimelate dehydrogenase branch to overproduce lysine. this mutant strain grew and utilized glucose from minimal medium at the same rate as the parental strain. in addition, the dape- strain produced lysine at the same rate as ... | 1999 | 10222581 |
| d-pantothenate synthesis in corynebacterium glutamicum and use of panbc and genes encoding l-valine synthesis for d-pantothenate overproduction. | d-pantothenate is synthesized via four enzymes from ketoisovalerate, which is an intermediate of branched-chain amino acid synthesis. we quantified three of these enzyme activities in corynebacterium glutamicum and determined specific activities ranging from 0.00014 to 0.001 micromol/min mg (protein)-1. the genes encoding the ketopantoatehydroxymethyl transferase and the pantothenate synthetase were cloned, sequenced, and functionally characterized. these studies suggest that panbc constitutes a ... | 1999 | 10223988 |
| identification and disruption of betl, a secondary glycine betaine transport system linked to the salt tolerance of listeria monocytogenes lo28. | the trimethylammonium compound glycine betaine (n,n, n-trimethylglycine) can be accumulated to high intracellular concentrations, conferring enhanced osmo- and cryotolerance upon listeria monocytogenes. we report the identification of betl, a gene encoding a glycine betaine uptake system in l. monocytogenes, isolated by functional complementation of the betaine uptake mutant escherichia coli mkh13. the betl gene is preceded by a consensus sigmab-dependent promoter and is predicted to encode a 55 ... | 1999 | 10224004 |
| nitrogen regulation in corynebacterium glutamicum: isolation of genes involved and biochemical characterization of corresponding proteins. | the regulation of nitrogen assimilation was investigated in the gram-positive actinomycete corynebacterium glutamicum. biochemical studies and site-directed mutagenesis revealed that glutamine synthetase activity is regulated via adenylylation in this organism. the genes encoding the central signal transduction protein ph (glnb) and the primary nitrogen sensor uridylyltransferase (glnd) were isolated and sequenced. additionally, genes putatively involved in the degradation of ornithine (ocd) and ... | 1999 | 10227160 |
| positively regulated expression of the escherichia coli arabad promoter in corynebacterium glutamicum. | in corynebacterium glutamicum the promoter of the arabad escherichia coli gene is positively regulated by both arabinose and the arac gene product, as it is the case in the natural host. if the l-arabinose inducer and an active arac gene are present, significant amounts of arabad promoter expression take place in the absence of the e. coli crp protein. these results show that the c. glutamicum rna polymerase is activated by the e. coli positive regulator of transcription arac. | 1999 | 10234830 |
| hyperproduction of tryptophan by corynebacterium glutamicum with the modified pentose phosphate pathway. | a classically derived tryptophan-producing corynebacterium glutamicum strain was recently significantly improved both by plasmid-mediated amplification of the genes for the rate-limiting enzymes in the terminal pathways and by construction of a plasmid stabilization system so that it produced more tryptophan. this engineered strain, ky9218 carrying pkw9901, produced 50 g of tryptophan per liter from sucrose after 80 h in fed-batch cultivation without antibiotic pressure. analysis of carbon balan ... | 1999 | 10347033 |
| isolation of the muri gene from brevibacterium lactofermentum atcc 13869 encoding d-glutamate racemase. | the muri gene encoding d-glutamate racemase plays an important role in the biosynthesis of d-glutamic acid, an essential component of cell wall peptidoglycan of almost all eubacteria. a dna fragment that could rescue the auxotrophy of d-glutamic acid in the escherichia coli muri mutant strain wm335 was isolated from brevibacterium lactofermentum atcc 13869 belonging to the coryneform bacteria. dna sequencing reveals that it encodes a protein of 284 amino acid residues, which shows a high level o ... | 1999 | 10386367 |
| expression of the escherichia coli catabolic threonine dehydratase in corynebacterium glutamicum and its effect on isoleucine production. | the catabolic or biodegradative threonine dehydratase (e.c. 4.2.1. 16) of escherichia coli is an isoleucine feedback-resistant enzyme that catalyzes the degradation of threonine to alpha-ketobutyrate, the first reaction of the isoleucine pathway. we cloned and expressed this enzyme in corynebacterium glutamicum. we found that while the native threonine dehydratase of c. glutamicum was totally inhibited by 15 mm isoleucine, the heterologous catabolic threonine dehydratase expressed in the same st ... | 1999 | 10388709 |
| a special reactor design for investigations of mixing time effects in a scaled-down industrial l-lysine fed-batch fermentation process | a specially designed model reactor based on a 42-l laboratory fermentor was equipped with six stirrers (rushton turbines) and five cylindrical disks. in this model reactor, the mixing time, theta(90), turned out to be 13 times longer compared with the 42-l standard laboratory fermentor fitted with two rushton turbines and four wall-fixed longitudinal baffles. to prove the suitability of the model reactor for scaledown studies of mixing-time-dependent processes, parallel exponential fed-batch cul ... | 1999 | 10404240 |
| analysis of corynebacterium glutamicum methionine biosynthetic pathway: isolation and analysis of metb encoding cystathionine gamma-synthase. | the metb gene encoding cystathionine y-synthase, the second enzyme of methionine biosynthetic pathway, was isolated from a psl109-based corynebacterium glutamicum gene library via complementation of an escherichia coli metb mutant. a dna-sequence analysis of the cloned dna identified an open-reading frame of 1161 bp which encodes a protein with the molecular weight of 41,655 comprising of 386 amino acids. the putative protein product showed good amino acid-sequence homology to its counterpart in ... | 1999 | 10420990 |
| cloning of the argf gene encoding the ornithine carbamoyltransferase from corynebacterium glutamicum. | the argf gene encoding ornithine carbamoyl-transferase (otcase; ec2.1.3.3) has been cloned from corynebacterium glutamicum by transforming the escherichia coli arginine auxotroph with the genomic dna library. the cloned dna also complements the e. coli argg mutant, suggesting a clustered organization of the genes in the genome. we have determined the dna sequence of the minimal fragment complementing the e. coli argf mutant. the coding region of the cloned gene is 957 nucleotides long with a ded ... | 1999 | 10420995 |
| ribonucleotide reductase (rnr) of corynebacterium glutamicum atcc 13032--genetic characterization of a second class iv enzyme. | ribonucleotide reductases (rnrs) encoded by nrd (nucleotide reduction) genes are unique enzymes providing the dna precursors in all living organisms and several viruses. the designation of four classes of rnrs reflects their use of diverse metallo-cofactors. using oligonucleotide primers derived from conserved domains of the primary structure of known nrda and nrde proteins, an internal 938 bp fragment of the nrde gene was amplified from genomic dna of corynebacterium glutamicum. with this pcr p ... | 1999 | 10439398 |
| crystallization and preliminary x-ray diffraction studies of monomeric isocitrate dehydrogenase from corynebacterium glutamicum. | a monomeric isocitrate dehydrogenase has been crystallized for the first time. this enzyme catalyzes the conversion of isocitrate to oxalosuccinate and subsequently to alpha-ketoglutarate and co(2); the coenzyme nadp(+) is reduced to nadph during the reaction. polyethylene glycol 2000 monomethyl ether was used to crystallize the enzyme in space group c2 with unit-cell parameters a = 137.1, b = 54.6, c = 126.4 a, beta = 108.2 degrees. the very small crystal (0. 05 x 0.20 x 0.05 mm) diffracted to ... | 1999 | 10489453 |
| analysis of the corynebacterium glutamicum dapa promoter. | deletion and mutational analysis of the promoter p-dapa from corynebacterium glutamicum was performed to identify regions and particular nucleotides important for its function. an extended -10 region and a stretch of six t's at positions -55 to -50 were found to be the most important elements in the promoter function. the results of mutational analysis of p-dapa are consistent with the conclusions of statistical computer-aided analysis of 44 c. glutamicum promoter sequences. | 1999 | 10498736 |
| sequence analysis and expression of the aspartokinase and aspartate semialdehyde dehydrogenase operon from rifamycin sv-producing amycolatopsis mediterranei. | a approximately 4.8 kb kpni fragment, from the upstream region of the methylmalonyl-coa mutase gene (mutab) of rifamycin sv-producing amycolatopsis mediterranei, was cloned and partially sequenced. codon preference analysis showed three complete orfs. orf2 is internal to orf1, and encodes a polypeptide corresponding to 172 amino acids, whereas orf1 encodes a polypeptide of 421 amino acids. they were identified as the encoding genes of aspartokinase alpha- and beta-subunits by comparing the amino ... | 1999 | 10521665 |
| establishment of a gene transfer system for rhodococcus opacus pd630 based on electroporation and its application for recombinant biosynthesis of poly(3-hydroxyalkanoic acids). | a gene transfer system for rhodococcus opacus pd630 based on electroporation was established and optimized employing the escherichia coli-rhodococcus shuttle vectors pnc9501 and pnc9503 as well as the e. coli-corynebacterium glutamicum shuttle vector pjc1 as suitable cloning vectors for r. opacus pd630, resulting in transformation efficiencies up to 1.5 x 10(5) cfus/microgram plasmid dna. applying the optimized electroporation protocol to the pnc9501-derivatives pak68 and pak71 harboring the ent ... | 1999 | 10570798 |
| a heat shock following electroporation induces highly efficient transformation of corynebacterium glutamicum with xenogeneic plasmid dna. | an improved method for the electrotransformation of wild-type corynebacterium glutamicum (atcc 13032) is described. the two crucial alterations to previously developed methods are: cultivation of cells used for electrotransformation at 18 degrees c instead of 30 degrees c, and application of a heat shock immediately following electrotransformation. cells cultivated at sub optimal temperature have a 100-fold improved transformation efficiency (10(8) cfu micrograms-1) for syngeneic dna (dna isolat ... | 1999 | 10570802 |
| characterization of activity and expression of isocitrate lyase in mycobacterium avium and mycobacterium tuberculosis. | analysis by two-dimensional gel electrophoresis revealed that mycobacterium avium expresses several proteins unique to an intracellular infection. one abundant protein with an apparent molecular mass of 50 kda was isolated, and the n-terminal sequence was determined. it matches a sequence in the m. tuberculosis database (sanger) with similarity to the enzyme isocitrate lyase of both corynebacterium glutamicum and rhodococcus fascians. only marginal similarity was observed between this open readi ... | 1999 | 10572116 |
| a method for the determination of pyruvate carboxylase activity during the glutamic acid fermentation with corynebacterium glutamicum. | a discontinuous lactate dehydrogenase coupled assay is described for the evaluation of the pyruvate carboxylase activity (pc, ec 6.4.1.1) in a glutamate overproducing strain of corynebacterium glutamicum. after an initial permeabilisation period of the cells, the method consisted of the fluorometric determination of the remaining pyruvate level after transformation into oxaloacetate by the endogenous pc. the assay was demonstrated to be powerful and enabled the determination of the c. glutamicum ... | 1999 | 10579510 |
| molecular analysis of the corynebacterium glutamicum transketolase gene. | transketolase is important in production of the aromatic amino acids in corynebacterium glutamicum. the complete nucleotide sequence of the c. glutamicum transketolase gene has been identified. the dna-derived protein sequence is highly similar to the transketolase of mycobacterium tuberculosis, taxonomically related to c. glutamicum. the alignment of the n-terminus regions between both transketolases showed ttg to be the most probable start codon. potential ribosomal binding and promoter region ... | 1999 | 10586507 |
| the corynebacterium glutamicum insertion sequence iscg2 prefers conserved target sequences located adjacent to genes involved in aspartate and glutamate metabolism. | an is element, termed iscg2, was identified in the chromosome of corynebacterium glutamicum atcc 13032. after screening a cosmid library of the c. glutamicum atcc 13032 genome, six copies of iscg2 including their flanking regions were sequenced and analyzed. iscg2 is 1636 bp in length and has 26-bp imperfect inverted repeats flanked by 3-bp direct repeats. by comparisons with other is elements, iscg2 was classified as a member of the is30 family of insertion sequences. the six copies of iscg2 we ... | 1999 | 10589846 |
| class 1 integrons, gene cassettes, mobility, and epidemiology. | integrons are genetic elements that, although unable to move themselves, contain gene cassettes that can be mobilized to other integrons or to secondary sites in the bacterial genome. the majority of approximately 60 known gene cassettes encode resistance to antibiotics. recently, a number of gene cassettes encoding extended-spectrum beta-lactamases or carbapenemases have been described. up to at least five cassettes may be present in an integron, which leads to multiresistance. frequently, more ... | 1999 | 10614949 |
| osmosensor and osmoregulator properties of the betaine carrier betp from corynebacterium glutamicum in proteoliposomes. | the secondary glycine betaine uptake system betp of corynebacterium glutamicum was purified from escherichia coli membranes in strep-tagged form after heterologous expression of the betp gene and was reconstituted in e. coli lipids. betp retained its kinetic properties (v(max) and k(m) for betaine and na(+)) as compared with intact cells. the influence of driving forces (na(+) gradient and/or electrical potential) on betaine uptake was quantified in proteoliposomes. betp was effectively regulate ... | 2000 | 10625602 |
| comparative study of the effects of peptidoglycan monomer and structurally related adamantyltripeptides on humoral immune response to ovalbumin in the mouse. | peptidoglycan monomer, glcnac-murnac-l-ala-d-isogln-mesodap(omega nh2)-d-ala-d-ala (pgm) originating from brevibacterium divaricatum and synthetic adamantyltripeptides, diastereoisomers of d,l-(adamant-2-yl)-gly-l-ala-d-isogln (adtp1 and adtp2) exhibit immunomodulating activity. an experimental model in the mouse has been established with suboptimal amounts of ovalbumin (ova) as the immunogen, and parallel testing of adjuvant activity of these three immunomodulators was carried out in balb/c, c5 ... | 2000 | 10649625 |
| pulsed high-field gradient in vivo nmr spectroscopy to measure diffusional water permeability in corynebacterium glutamicum. | pulsed high-field gradient in vivo nmr spectroscopy was used to measure diffusional water permeability in cell suspensions of the gram-positive bacterium corynebacterium glutamicum. two different regions of h2o mobility were detected. one was characterized by the apparent coefficient of self-diffusion, d(1 app) = (4.6-12.7)x10(-8) cm(2) s(-1), depending on the observation time t. the other region was characterized by d(2) = 1.4x10(-5) cm(2) s(-1). the value of d(2) was similar to the diffusion c ... | 2000 | 10683237 |
| reductive cleavage of demeton-s-methyl by corynebacterium glutamicum in cometabolism on more readily metabolizable substrates. | corynebacterium glutamicum is able to biotransform demeton-s-methyl, an organophosphorus compound, during cometabolism with more readily metabolizable substrates. among the cosubstrates used, fructose is the growth substrate that is most favorable for demeton-s-methyl biotransformation. the reaction mechanism of demeton-s-methyl biotransformation involves reductive cleavage of an s-c bond, which leads to accumulation of dimethyl thiophosphate in the culture medium. | 2000 | 10698792 |
| metabolic flux distributions in corynebacterium glutamicum during growth and lysine overproduction. reprinted from biotechnology and bioengineering, vol. 41, pp 633-646 (1993). | the two main contributions of this article are the solidification of corynebacterium glutamicum biochemistry guided by bioreaction network analysis, and the determination of basal metabolic flux distributions during growth and lysine synthesis. employed methodology makes use of stoichiometrically based mass balances to determine flux distributions in the c. glutamicum metabolic network. presented are a brief description of the methodology, a thorough literature review of glutamic acid bacteria b ... | 2000 | 10699864 |
| characterization of the in vivo acceptors of the mycoloyl residues transferred by the corynebacterial ps1 and the related mycobacterial antigens 85. | mycolic acids, long-chain (c70-c90) alpha-alkyl, beta-hydroxy fatty acids, are characteristic cell envelope components of mycobacteria; similar but shorter-chain substances occur in corynebacteria and related taxa. these compounds apparently play an important role in the physiology of these bacteria. the deduced n-terminal region of ps1, one of the two major secreted proteins of corynebacterium glutamicum encoded by the csp1 gene, is similar to the antigens 85 complex of mycobacterium tuberculos ... | 2000 | 10712685 |