| mode of action of myxococcus xanthus antibiotic ta. | antibiotic ta inhibited incorporation of diaminopimelic acid and uridine diphosphate-n-acetylglucosamine into escherichia coli cell walls without altering the ratio of cross-linked to uncross-linked peptidoglycan. formation of the lipid intermediate was not blocked by ta, suggesting that ta interferes with polymerization of the lipid-disaccharide-pentapeptide. | 1981 | 6812494 |
| pyrrolnitrin from myxococcus fulvus (myxobacterales). | | 1982 | 6815147 |
| chemical properties of myxococcus xanthus antibiotic ta. | antibiotic ta was purified and crystallized from culture fluids of myxococcus xanthus ta. the antibiotic (c34h57o9n, m.w. 623.8) contained the following functional groups: ketone, lactone, secondary amide, methoxy-substituted diene (lambda max 239 nm), primary alcohol and three secondary alcohols, two of which were cis-vicinal. mild alkaline hydrolysis opened the lactone with concomitant loss of antibiotic activity. periodate oxidation also destroyed biological activity. | 1982 | 6816780 |
| the myxovirescins, a family of antibiotics from myxococcus virescens (myxobacterales). | the myxobacterium, myxococcus virescens strain mx v48 produced a family of at least 12 closely related antibiotics, the myxovirescins. at a concentration of 1 to 5 micrograms/ml, the main component, myxovirescin a, was bactericidal for many gram-negative bacteria, in particular enterobacteria, and at 20 to 50 micrograms/ml it also inhibited some pseudomonads and gram-positive bacteria. the antibiotics seem to interfere with cell wall synthesis. the molecular formula of myxovirescin a was c35h61n ... | 1982 | 6819280 |
| evolutionary relationship between halobacterium cutirubrum and eukaryotes determined by use of aminoacyl-trna synthetases as phylogenetic probes. | the cross-species reactivities between trnas and aminoacyl-trna synthetases have been employed as a basis to estimate the relatedness of various prokaryotes to the eukaryotes. the trna of halobacterium cutirubrum, unlike that of other prokaryotes tested, including agrobacterium tumefaciens, arthrobacter luteus, bacillus subtilis, bacillus stearothermophilus, escherichia coli, micrococcus luteus, myxococcus xanthus, rhodopseudomonas spheroides, and thermus aquaticus, was found to share with yeast ... | 1980 | 6989454 |
| bacteriophage k7, a double stranded dna phage that infects strains of escherichia coli harbouring drug resistance factors of incompatability group w. | bacteriophage k7 is specific for escherichia coli strains harbouring r factors of incompatability group w, including hybrid coliphage p1-myxococcus virescens plasmids. the phage has an unusual morphology with an isometric head and long tail of variable length. the tail lengths appear to fall into classes corresoonsing to simple multimers of a unit length. partially purified lysates of the phage include material that may represent phage particles in the process of biogenesis and other material de ... | 1980 | 6996631 |
| myxothiazol, a new antibiotic interfering with respiration. | myxothiazol, a new antibiotic from the myxobacterium myxococcus fulvus, inhibited the growth of many yeasts and fungi at concentrations between 0.01 and 3 micrograms/ml. it was generally inactive against bacteria. the inhibitory effect was cytostatic. with candida albicans, saccharomyces cerevisiae, and mucor hiemalis, the growth inhibition was neutralized by glucose. soon after being added to a cell suspension, the compound almost completely blocked oxygen consumption. | 1981 | 7247372 |
| myxothiazol, an antibiotic from myxococcus fulvus (myxobacterales). ii. structure elucidation. | myxothiazol is shown to be 4-(6-carbamoyl-3,5-dimethoxy-4-methylhexa-1e,5e-dienyl)-2'-(1,6-dimethylhepta-2 e,4e-dienyl)-2,4'-bithiazole by spectroscopic (mainly 1h nmr, 15c nmr and mass spectroscopic) and chemical methods. | 1980 | 7271921 |
| a tactile sensory system of myxococcus xanthus involves an extracellular nad(p)(+)-containing protein. | csga is a cell surface protein that plays an essential role in tactile responses during myxococcus xanthus fruiting body formation by producing the morphogenic c-signal. the primary amino acid sequence of csga exhibits homology with members of the short-chain alcohol dehydrogenase (scad) family and several lines of evidence suggest that nad(p)+ binding is essential for biological activity. first, the predicted csga secondary structure based on the 3 alpha/20 beta-hydroxysteroid dehydrogenase cry ... | 1995 | 7498792 |
| a gene encoding a protein related to eukaryotic protein kinases from the filamentous heterocystous cyanobacterium anabaena pcc 7120. | protein kinases play essential roles in the development of eukaryotic cells. these enzymes display various degrees of sequence similarity in their catalytic domains. this conservation has allowed the identification of protein kinases in a variety of organisms, including the gram-negative bacterium myxococcus xanthus. in this study, sequences related to those encoding eukaryotic protein kinases were amplified by pcr from dna of anabaena pcc 7120, a filamentous cyanobacterium that differentiates c ... | 1993 | 7505448 |
| autolytic effect of the antibiotic produced by myxococcus coralloides d. | myxococcus coralloides d secretes an antibiotic, named corallolysin, when grown on a rich medium. when a critical concentration is reached, this antibiotic lyses the producer bacterium either during vegetative growth or during morphogenesis. corallolysin has not effect on resting cells nor on myxospores. the autolytic effect is caused by the early inhibition of rna synthesis. | 1994 | 7539617 |
| a new myxococcus xanthus gene cluster for the biosynthesis of the antibiotic saframycin mx1 encoding a peptide synthetase. | the gene cluster for the biosynthesis of the heterocyclic quinone antibiotic saframycin mx1 of myxococcus xanthus dm504/15 was inactivated and tagged by tn5 insertions. the tagged genes were cloned in escherichia coli and used to select overlapping cosmid clones spanning 58 kb of the m. xanthus genome. gene disruption experiments defined a > or = 18 kb contiguous dna region involved in saframycin biosynthesis. sequencing of part of this region revealed a large orf containing two 600-amino-acid d ... | 1995 | 7551044 |
| branched-chain fatty acids: the case for a novel form of cell-cell signalling during myxococcus xanthus development. | the esg locus is required for the formation of multicellular fruiting bodies and spores by the developmental bacterium myxococcus xanthus. studies have suggested that esg mutants are defective in the production of an essential signal (e-signal) used in cell-cell communication and that e-signalling is required for the expression of many developmental genes. recently we have determined that the esg locus encodes components of a branched-chain keto acid dehydrogenase, a multienzyme complex involved ... | 1995 | 7565080 |
| the esg locus of myxococcus xanthus encodes the e1 alpha and e1 beta subunits of a branched-chain keto acid dehydrogenase. | the esg locus of myxococcus xanthus appears to control the production of a signal that must be transmitted between cells for the completion of multicellular development. dna sequence analysis suggested that the esg locus encodes the e1 decarboxylase (composed of e1 alpha and e1 beta subunits) of a branched-chain keto acid dehydrogenase (bckad) that is involved in branched-chain amino acid (bcaa) metabolism. the properties of an esg::tn5 insertion mutant supported this conclusion. these propertie ... | 1995 | 7565081 |
| a cluster of structural and regulatory genes for light-induced carotenogenesis in myxococcus xanthus. | in the bacterium myxococcus xanthus, several genes for carotenoid synthesis lie together at the cara-carb chromosomal locus and are co-ordinately activated by blue light. a 12-kb dna stretch from wild-type m. xanthus has been sequenced that includes the entire cara-carb gene cluster. according to sequence analysis, the cluster contains 11 different genes. intergenic distances are very short or nil (implying translational coupling), giving further support to previous evidence indicating that most ... | 1995 | 7588751 |
| gliding movements in myxococcus xanthus. | prokaryotic gliding motility is described as the movement of a cell on a solid surface in the direction of the cell's long axis, but its mechanics are unknown. to investigate the basis of gliding, movements of individual myxococcus xanthus cells were monitored by employing a video microscopy method by which displacements as small as 0.03 micron could be detected and speeds as low as 1 micron/min could be resolved. single cells were observed to glide with speeds varying between 1 and 20 microns/m ... | 1995 | 7592333 |
| using a phase-locked mutant of myxococcus xanthus to study the role of phase variation in development. | the bacterium myxococcus xanthus undergoes a primitive developmental cycle in response to nutrient deprivation. the cells aggregate to form fruiting bodies in which a portion of the cells differentiate into environmentally resistant myxospores. during the growth portion of the m. xanthus life cycle, the organism also undergoes a phase variation, in which cells alternate between yellow and tan colony-forming variants. phase variation occurs in our laboratory strain (m102, a derivative of dk1622) ... | 1995 | 7608083 |
| two reca genes in myxococcus xanthus. | two reca genes, reca1 and reca2, in myxococcus xanthus were cloned by using the reca gene of escherichia coli, and their dna sequences were determined. on the basis of deduced amino acid sequences, reca1 and reca2 have 67.0% identity to each other and 60.5 and 60.9% identities to e. coli reca, respectively. expression of reca2 was detected in both vegetative and developmental cells by northern blot (rna) analysis, and a threefold induction was observed when cells were treated with nalidixic acid ... | 1995 | 7608099 |
| ectopic production of guanosine penta- and tetraphosphate can initiate early developmental gene expression in myxococcus xanthus. | amino acid or carbon limitation is sufficient to initiate fruiting body development in myxococcus xanthus. in both escherichia coli and m. xanthus the levels of guanosine 3'-di-5'-(tri)di-phosphate nucleotides [(p)ppgpp] rise transiently when cells are starved for amino acids or carbon. ectopic increase in the intracellular concentration of (p)ppgpp was achieved in m. xanthus by introducing a copy of the e. coli rela gene, whose product catalyzes pyrophosphate transfer from atp- to gtp-forming p ... | 1995 | 7628697 |
| germination of myxospores from the fruiting bodies of myxococcus xanthus. | germination of myxospores from fruiting bodies of myxococcus xanthus was examined under a light microscope as well as by analyzing the incorporation of [3h]uracil into the rna fraction. efficient germination was observed in 0.2% casitone containing 8 mm mgso4 and 1 mm cacl2 at 30 degrees c. under this condition, spherical myxospores were converted into rod-shaped vegetative cells within 5 to 6 h. the germination was severely inhibited in the presence of 1 mm phenylmethylsulfonyl fluoride, a prot ... | 1995 | 7635813 |
| an early a-signal-dependent gene in myxococcus xanthus has a sigma 54-like promoter. | a-signaling plays an essential role in the early stages of myxococcus xanthus fruiting body development. expression of the 452i gene, which is regulated at the level of rna accumulation, depends on starvation and on a-signaling. to identify the cis-acting regulatory elements which allow gene 4521 to respond to the nutritional and a-factor signals, the 4521 transcription start site was mapped. the region just upstream of the start site showed sequence similarity to the sigma 54 family of promoter ... | 1995 | 7642489 |
| identification of the minimum regulatory region of a myxococcus xanthus a-signal-dependent developmental gene. | developmental expression of the myxococcus xanthus gene 4521 requires extracellular a-signal. this signal is generated in response to nutrient limitation and functions in cell density sensing. to identify the upstream limit of the minimum region required in vivo for a-signal-dependent 4521 expression, a 5' deletion analysis of the 4521 regulatory region was performed. a new vector, phbk280, was designed to facilitate this analysis. this vector creates tandem copies of the 4521 gene in the m. xan ... | 1995 | 7642490 |
| the crystal structure of a human nucleoside diphosphate kinase, nm23-h2. | the 2.8 a resolution x-ray structure of nm23-h2 has been determined by molecular replacement using the structure of myxococcus xanthus nucleoside diphosphate (ndp) kinase. nm23-h2 is a human ndp kinase. the enzyme catalyses phosphoryl transfer, binds dna, and can activate the transcription of the c-myc oncogene in vitro. nm23 has also been reported to be a suppressor of metastasis in some types of tumours. whereas the m. xanthus ndp kinase is a tetramer, nm23-h2 is a hexamer. the fold of nm23-h2 ... | 1995 | 7658474 |
| methionine inhibits developmental aggregation of myxococcus xanthus by blocking the biosynthesis of s-adenosyl methionine. | previous studies showed that high concentrations of methionine (> 1 mm) inhibited aggregation and fruiting body formation in myxococcus xanthus (e. rosenberg, d. filer, d. zafriti, and s. h. kindler, j. bacteriol. 115: 29-34, 1973, and j. m. campos and d. r. zusman, proc. natl. acad. sci. usa 72:518-522, 1975). however, the mechanism for the inhibition was unclear. in this study, we found that high levels of methionine inhibited the biosynthesis of s-adenosylmethionine (sam) and that reduced int ... | 1995 | 7665525 |
| devrs, an autoregulated and essential genetic locus for fruiting body development in myxococcus xanthus. | two tn5 lac insertions into the myxococcus genome at sites omega 4414 and omega 4473, which are separated by 550 nucleotides, inactivate fruiting body development. sporulation is decreased 100- to 10,000-fold. at least two genes, devr and devs, are transcribed in this region, probably as an operon. expression of devr begins by 6 h after starvation has initiated development. on the basis of their nucleotide sequences, devr and devs are expected to encode proteins of 302 and 214 amino acids, respe ... | 1993 | 7693658 |
| nm23/nucleoside diphosphate kinase: toward a structural and biochemical understanding of its biological functions. | the nm23 gene, a putative metastasis suppressor gene, was originally identified by its reduced expression in highly metastatic k-1735 murine melanoma cell lines, as compared to related, low metastatic melanoma cell lines. transfection of nm23 cdna has been reported to suppress malignant progression in drosophila and mammalian cells. highly conserved homologues of nm23 have been found in organisms ranging from the prokaryote myxococcus xanthus to drosophila, where the gene is involved in normal d ... | 1995 | 7702594 |
| the myxococcus xanthus asga gene encodes a novel signal transduction protein required for multicellular development. | the myxococcus xanthus asga gene is one of three known genes necessary for the production of extracellular a-signal, a cell density signal required early in fruiting body development. we determined the dna sequence of asga. the deduced 385-amino-acid sequence of asga was found to contain two domains: one homologous to the receiver domain of response regulators and the other homologous to the transmitter domain of histidine protein kinases. a kanamycin resistance (kmr) gene was inserted at variou ... | 1995 | 7721694 |
| myxococcus xanthus, a gram-negative bacterium, contains a transmembrane protein serine/threonine kinase that blocks the secretion of beta-lactamase by phosphorylation. | a gene, pkn2, encoding a myxococcus xanthus protein with significant similarities to eukaryotic protein serine/threonine kinases, was cloned using the polymerase chain reaction. the open reading frame for the protein, beginning with a gug initiation codon, consists of 830 amino acids. the amino-terminal 279 residues show 37% identity to catalytic domain of pkn1, another protein serine/threonine kinase expressed during the development at the onset of sporulation. the catalytic domain of pkn2 cont ... | 1995 | 7774814 |
| the 1.9 a crystal structure of a nucleoside diphosphate kinase complex with adenosine 3',5'-cyclic monophosphate: evidence for competitive inhibition. | the x-ray structure of myxococcus xanthus nucleoside diphosphate (ndp) kinase complexed with adenosine 3',5'-cyclic monophosphate (camp) has been determined. the structure was solved by difference fourier analysis. the refined structure has a crystallographic r-factor of 0.17 at 1.9 a resolution. the phosphoryl group and ribose moiety make extensive polar interactions with the protein, whereas the base interacts only with two hydrophobic residues. the comparison with the structure of the enzyme ... | 1995 | 7783219 |
| genetic suppression and phenotypic masking of a myxococcus xanthus frzf- defect. | an insertion of transposon tn5-lac, omega 4519, generates a lacz fusion with a myxococcus xanthus promoter expressed during both vegetative growth and development. sequence analysis of the junction of omega 4519 with m. xanthus dna shows that the insertion is in frzf, a homologue of cher from salmonella typhimurium. when frzf- (or frzcd-) cells are starved for nutrients at modest densities, they aggregate to form a radial pattern and produce fewer than 1% of the wild-type complement of spores. a ... | 1995 | 7783619 |
| the pseudomonas aeruginosa pilk gene encodes a chemotactic methyltransferase (cher) homologue that is translationally regulated. | a new locus, designated pilk, located immediately adjacent to the previously described pseudomonas aeruginosa pilg-j gene cluster, has been identified. sequence analysis of a 1.3 kb region revealed the presence of a single open reading frame of 291 amino acid residues (m(r) 33,338) that contained significant homology to the chemotactic methyltransferase proteins of escherichia coli, bacillus subtilis and the gliding bacterium myxococcus xanthus. the 60 bp pilj-pilk intergenic region was devoid o ... | 1995 | 7783642 |
| the gene encoding the beta-1,4-endoglucanase (cela) from myxococcus xanthus: evidence for independent acquisition by horizontal transfer of binding and catalytic domains from actinomycetes. | the cela gene encoding a beta-1,4 endoglucanase (cela) from myxococcus xanthus has been cloned in escherichia coli and sequenced. the c-terminal region of cela displayed a high level of similarity with the catalytic domain of several egl belonging to the glycosyl hydrolases family 6 (cena from cellulomonas fimi, cela from microbispora bispora, e2 from thermonospora fusca, casa from streptomyces ksm9 and cela1 from streptomyces halstedii) and less similarity to the cellobiohydrolases of the fungi ... | 1995 | 7789807 |
| phylogenetic comparison of retron elements among the myxobacteria: evidence for vertical inheritance. | twenty-eight myxobacterial strains, representing members from all three subgroups, were screened for the presence of retron elements, which are novel prokaryotic retroelements encoding reverse transcriptase. the presence of retrons was determined by assaying strains for a small satellite dna produced by reverse transcription called multicopy, single-stranded dna (msdna). an msdna-producing retron appeared to be absent from only one of the strains surveyed. dna hybridization experiments revealed ... | 1995 | 7798147 |
| endogenous adp-ribosylation during development of the prokaryote myxococcus xanthus. | we examined endogenous adp-ribosylation of proteins during the development of the prokaryote myxococcus xanthus. in vivo and in vitro endogenous adp-ribosylation of m. xanthus proteins was detected and the profile of modified proteins changed during development. adenosine and nicotinamide inhibited adp-ribosylation. nicotinamide stimulated cells at low density to develop, in a manner similar to that previously observed with adenosine. higher concentrations of nicotinamide inhibited aggregation. ... | 1994 | 7812456 |
| the 'chea' and 'chey' domains of myxococcus xanthus frze function independently in vitro as an autokinase and a phosphate acceptor, respectively. | frze is a chemotaxis protein in myxococcus xanthus which has sequence homology to two different chemotaxis proteins of enteric bacteria, chea (autokinase) and chey (phosphate acceptor) [proc. natl. acad. sci. usa 87 (1990) 5898-5902]. it was also shown that a recombinant frze protein was autophosphorylated when incubated in the presence of atp and mn2+ [j. bacteriol. 172 (1990) 6661-6668]. in this study, we further investigated the biochemical properties of frze. two recombinant proteins were pr ... | 1995 | 7821424 |
| new clusters of genes required for gliding motility in myxococcus xanthus. | gliding is the directed movement of cells across surfaces which occurs in the absence of external organelles such as flagella. gliding of the complex prokaryote, myxococcus xanthus, results from the action of two independent sets of genes known as the a (adventurous motility) and s (social motility) genes. strains with mutations in both systems (a-s-) do not spread on agar surfaces because both individual and group movement is abolished. to generate regulated, transcriptional fusions with operon ... | 1994 | 7830561 |
| sensor/response in myxococcus xanthus to attractants and repellents requires the frz signal transduction system. | | 1994 | 7855429 |
| an endo-n-acetyl-beta-d-glucosaminidase, acting on the di-n-acetylchitobiosyl part of n-linked glycans, is secreted during sporulation of myxococcus xanthus. | after the demonstration that stigmatella aurantiaca dw4 secretes an endo-n-acetyl-beta-d-glucosaminidase (engase), acting on the di-n-acetylchitobiosyl part of n-linked glycans (s. bourgerie, y. karamanos, t. grard, and r. julien, j. bacteriol. 176:6170-6174, 1994), an engase activity having the same substrate specificity was also found to be secreted during vegetative growth of myxococcus xanthus dk1622. the activity decreased in mutants known to secrete less protein than the wild type (exc +/- ... | 1995 | 7860600 |
| cloning, expression, and characterization of the lon gene of erwinia amylovora: evidence for a heat shock response. | the gene encoding the lon protease of erwinia amylovora has been cloned by complementation of an escherichia coli lon mutant. analysis of the determined nucleotide sequence of the lon gene revealed extensive homology to the nucleotide sequences of cloned lon genes from e. coli, myxococcus xanthus, and bacillus brevis. the predicted amino acid sequence of the e. amylovora lon protease was 94, 59, and 54% identical to the predicted amino acid sequences of the lon proteases of e. coli, m. xanthus, ... | 1995 | 7860603 |
| identification of genes negatively regulated by fis: fis and rpos comodulate growth-phase-dependent gene expression in escherichia coli. | fis is a nucleoid-associated protein in escherichia coli that has been shown to regulate recombination, replication, and transcription reactions. it is expressed in a transient manner under batch culturing conditions such that high levels are present during early exponential phase and low levels are present during late exponential phase and stationary phase. we have screened a random collection of transposon-induced lac fusions for those which give decreased expression in the presence of fis. th ... | 1995 | 7860604 |
| [three-dimensional structure of an extracellular calcium binding protein, protein s. spore adhesion in myxobacteria]. | | 1994 | 7884274 |
| genes required for both gliding motility and development in myxococcus xanthus. | myxococcus xanthus cells can glide both as individual cells, dependent on adventurous motility (a motility), and as groups of cells, dependent upon social motility (s motility). tn5-lac mutagenesis was used to generate 16 new a- and nine new s- mutations. in contrast with previous results, we find that subsets of a- mutants are defective in fruiting body morphogenesis and/or myxospore differentiation. all s- mutants are defective in fruiting body morphogenesis, consistent with previous results. ... | 1994 | 7891564 |
| sterol uptake induced by an impairment of pyridoxal phosphate synthesis in saccharomyces cerevisiae: cloning and sequencing of the pdx3 gene encoding pyridoxine (pyridoxamine) phosphate oxidase. | exogenous sterols do not permeate wild-type saccharomyces cerevisiae in aerobic conditions. however, mutant strain fkerg7, affected in lanosterol synthase, is a sterol auxotroph which is able to grow aerobically in the presence of ergosterol. viability of this strain depends on the presence of an additional mutation, aux30, that leads to sterol permeability. cells bearing the aux30 mutation fail to grow in standard yeast nitrogen base medium containing pyridoxine but grow normally if pyridoxine ... | 1995 | 7896706 |
| characterization of a pseudomonas aeruginosa gene cluster involved in pilus biosynthesis and twitching motility: sequence similarity to the chemotaxis proteins of enterics and the gliding bacterium myxococcus xanthus. | the type 4 pili of pseudomonas aeruginosa are important cell-associated virulence factors that play a crucial role in mediating (i) bacterial adherence to, and colonization of, mucosal surfaces, (ii) a novel mode of flagella-independent surface translocation known as 'twitching motility', and (iii) the initial stages of the infection process for a number of bacteriophages. a new set of loci involved in pilus biogenesis and twitching motility was identified based on the ability of dna sequences d ... | 1994 | 7908398 |
| autophosphorylation of nucleoside diphosphate kinase on non-histidine residues. | recently, several reports appeared which described auto-phosphorylation of ndp kinase on residues different from the active-site histidine. based on these findings conclusions were drawn with respect to a regulation of enzyme activity and to a possible role as a metastasis suppressor. in this paper we show that although non-histidine autophosphorylation occurs on ndp kinases from mammals, lower eukaryotes and bacteria, less than 0.2% of the subunits are phosphorylated. using site-directed mutage ... | 1994 | 7926021 |
| biochemical and structural analyses of the extracellular matrix fibrils of myxococcus xanthus. | it is characteristic of myxobacteria to produce large amounts of extracellular material. this report demonstrates that this material in myxococcus xanthus is fibrillar and describes the structure and chemical composition of the fibrils. the extracellular matrix fibrils are the mediators of cell-cell cohesion in m. xanthus. as such, the fibrils play an important role in the cell-cell interactions that form the basis for the social and developmental lifestyle of this organism. the fibrils are comp ... | 1994 | 7929001 |
| integral proteins of the extracellular matrix fibrils of myxococcus xanthus. | the extracellular matrix fibrils of myxococcus xanthus are mediators of cell-cell cohesion and as such are required for the maintenance of the social lifestyle characteristic of these prokaryotes. the fibrils have also been implicated as factors involved in contact-mediated cell interactions and in signal exchange. the fibrils are extracellular carbohydrate structures with associated proteins. all of the major proteins associated with the fibrils react with monoclonal antibody 2105 and can be re ... | 1994 | 7929002 |
| light-induced carotenogenesis in myxococcus xanthus: dna sequence analysis of the carr region. | the carr region encodes a light-inducible promoter, a negative regulator of the promoter and a trans-acting activator that controls the light-inducible myxococcus xanthus carotenoid biosynthesis regulon. dna sequence analysis revealed, downstream of the promoter, three translationally coupled genes, carq, carr and cars. sequencing of mutations demonstrated that carr encoded the negative regulator and was an integral membrane protein. mutant construction and sequencing revealed that cars was the ... | 1993 | 7934835 |
| a physical and genetic map of the stigmatella aurantiaca dw4/3.1 chromosome. | a physical map of the myxobacterium stigmatella aurantiaca dw4/3.1 chromosome was constructed by pulsed-field gel (pfg) long-range mapping. one-and two-dimensional pulsed-field gel analyses were used together with reciprocal double-restriction, cross-hybridization and hybridization fingerprint analysis. these pfg results were confirmed by smith-birnstiel analysis, by southern hybridization using linking clones and clones of a lambda genomic library for the determination of adjacent restriction f ... | 1993 | 7934859 |
| a physical map of the myxococcus xanthus chromosome. | a physical map of the 9.2-mbp myxococcus xanthus dk1622 chromosome at a resolution of 25 kbp was constructed by using a strategy that is applicable to virtually all microorganisms. segments of the chromosome were used as hybridization probes to subdivide a yeast artificial chromosome (yac) library into groups of linked clones. the clones were aligned by comparing their ecori restriction patterns. the groups of yac clones ("contigs") were oriented and aligned with the genomic restriction map by m ... | 1994 | 7937810 |
| elastolytic activity of map1, a protease from myxococcus xanthus. | map1, a protease isolated from myxococcus xanthus, is demonstrated to be an elastase. although its elastolytic activity is lower than that of other well-known elastases, the size distribution of solubilized elastin peptides is similar. map1 as pancreatic elastase releases peptides with molecular weights higher than 10,000. however, the specificity of map1 is different since this enzyme cannot hydrolyze alanine oligomers as do pancreatic and pseudomonas aeruginosa elastases. | 1994 | 7951071 |
| intercellular signalling. knowing that you're among friends. | factors that are simultaneously secreted and sensed are used by cells to monitor local cell density; a recently discovered factor of this type controls the transformation-competence of bacillus subtilis. | 1994 | 7953564 |
| a genetic link between light response and multicellular development in the bacterium myxococcus xanthus. | the gram-negative bacterium myxococcus xanthus responds to blue light by producing carotenoid pigments (car+ phenotype). genes for carotenoid synthesis lie at two unlinked chromosomal sites, the carc and the carba operon, but are integrated in a single "light regulon" by the action of common trans-acting regulatory elements. three known regulatory genes are grouped together at the (light-inducible) carqrs operon. by screening the car phenotype of a large collection of transposon-induced mutants, ... | 1994 | 7958903 |
| cloning, nucleotide sequence, and expression of the bacillus subtilis lon gene. | the lon gene of escherichia coli encodes the atp-dependent serine protease la and belongs to the family of sigma 32-dependent heat shock genes. in this paper, we report the cloning and characterization of the lon gene from the gram-positive bacterium bacillus subtilis. the nucleotide sequence of the lon locus, which is localized upstream of the hemaxcdbl operon, was determined. the lon gene codes for an 87-kda protein consisting of 774 amino acid residues. a comparison of the deduced amino acid ... | 1994 | 7961402 |
| isolated fibrils rescue cohesion and development in the dsp mutant of myxococcus xanthus. | extracellular fibrils are involved in cell cohesion and cell development in myxococcus xanthus. one group of social motility mutants, dsp, is unable to produce extracellular fibrils; these mutants also lose the abilities to cohere and to develop. extracellular fibrils isolated from vegetative wild-type cells and added to dsp cells fully restored the abilities of these cells to cohere and to undergo normal morphological development. the fibrils thus mimic the ability of intact, wild-type cells to ... | 1994 | 7961490 |
| refined x-ray structure of dictyostelium discoideum nucleoside diphosphate kinase at 1.8 a resolution. | the x-ray structure of the nucleoside diphosphate kinase (ndp kinase) from dictyostelium discoideum has been refined at 1.8 a resolution from a hexagonal crystal form with a 17 kda monomer in its asymmetric unit. the atomic model was derived from the previously determined structure of a point mutant of the protein. it contains 150 amino acid residues out of 155, and 95 solvent molecules. the r-factor is 0.196 and the estimated accuracy of the average atomic position, 0.25 a. the dictyostelium st ... | 1994 | 7966307 |
| clustering and co-ordinated activation of carotenoid genes in myxococcus xanthus by blue light. | blue light activates carotenoid production in the non-photosynthetic, gram-negative bacterium myxococcus xanthus. light is known to stimulate the expression of two unlinked genes for carotenoid synthesis, carb and carc, through a mechanism in which the regulatory genes cara, carq and carr take part. genes carq and carr are linked together at a separate locus, whereas cara is linked to carb. we have introduced tn5 at various sites between cara and carb. chemical analyses of the mutant strains dem ... | 1993 | 7968516 |
| increases in the intracellular concentration of glycerol during development in myxococcus xanthus. | the role of glycerol as a natural morphogen of myxospore formation in myxococcus xanthus was examined. glycerol was extracted from cells undergoing development and analyzed by gas chromatography. glycerol is present in cells, and the intracellular level undergoes a series of transient increases during development. the data suggest a role for glycerol in myxosporulation and fruiting body morphogenesis, supporting the notion that this chemical induction of sporulation may represent a physiological ... | 1994 | 7988874 |
| intercellular c-signaling and the traveling waves of myxococcus. | early in their development into fruiting bodies, myxococcus xanthus cells organize themselves into dense bands that move as trains of traveling waves. c-factor, a 20-kd cell-surface bound protein, is a short-range developmental signal molecule required for these waves. what is the role of c-factor in the wave pattern? it is proposed that oriented collisions between cells initiate c-signaling, which, in turn, causes individual cells to reverse their direction of gliding. cells would move about on ... | 1994 | 7995518 |
| molecular cloning and sequencing of an operon, carrs of azospirillum brasilense, that codes for a novel two-component regulatory system: demonstration of a positive regulatory role of carr for global control of carbohydrate catabolism. | a pleiotropic carbohydrate mutant, cr17, of azospirillum brasilense rg (wild type) that assimilates c4 dicarboxylates (succinate and malate) but not carbohydrate (fructose, arabinose, galactose, glycerol, and gluconate) as c sources for growth was used to identify the car (carbohydrate regulation) locus by complementation analysis. the 2.8-kb genomic fragment that complemented the car- defect of cr17 and overlapped the fru operon (s. chattopadhyay, a. mukherjee, and s. ghosh, j. bacteriol. 175:3 ... | 1994 | 8002571 |
| characterization of nucleoside-diphosphate kinase from pseudomonas aeruginosa: complex formation with succinyl-coa synthetase. | the enzyme nucleoside-diphosphate kinase (ndk), responsible for the conversion of (deoxy)ribonucleoside diphosphates to their corresponding triphosphates, has been purified from pseudomonas aeruginosa. the n-terminal 12 amino acid sequence of p. aeruginosa ndk shows significant homology with that of myxococcus xanthus and that of escherichia coli. ndk enzyme activity is also associated with succinyl-coa synthetase activity in p. aeruginosa, whose alpha and beta subunits show extensive sequence h ... | 1994 | 8016083 |
| protein purification, gene cloning and sequencing of an acidic endoprotease from myxococcus xanthus dk101. | an acidic endoprotease (maep) secreted during vegetative growth by myxococcus xanthus dk101 was purified to homogeneity by a series of chromatographic procedures. the endoprotease cleaved the phe-met bond of kappa-casein under acidic conditions (ph 5.9). its apparent molecular mass and its isoelectric point have been estimated to be 12 kda and 4.5, respectively. from the n-terminal amino acid sequence, a set of two primers for polymerase chain reaction have been designed. amplification of the co ... | 1994 | 8020464 |
| myxococcus xanthus c-factor, a morphogenetic paracrine signal, is similar to escherichia coli 3-oxoacyl-[acyl-carrier-protein] reductase and human 17 beta-hydroxysteroid dehydrogenase. | | 1994 | 8037687 |
| analysis of the streptomyces coelicolor sige gene reveals the existence of a subfamily of eubacterial rna polymerase sigma factors involved in the regulation of extracytoplasmic functions. | sigma e, an rna polymerase sigma factor of apparent m(r) 28,000, was previously identified by its ability to direct transcription from the p2 promoter of the agarose gene (daga) of streptomyces coelicolor. a degenerate oligonucleotide probe, designed from the n-terminal sequence of purified sigma e, was used to isolate the sigma e gene (sige). the predicted sequence of sigma e shows greatest similarity to sequences of seven other proteins: myxococcus xanthus carq, pseudomonas aeruginosa algu, ps ... | 1994 | 8052622 |
| purification and characterization of an alkaline elastase from myxococcus xanthus. | an extracellular elastase, termed myxococcus xanthus alkaline protease 1 (map1), has been purified from m. xanthus dk1622 culture supernatants by a combination of ion-exchange and affinity chromatographies. it consists of a single peptide chain of 39 kda. the elastolytic activity was totally suppressed by 10 mm 1,10-phenanthroline and the enzyme may then be classified as a metalloprotease. its ph optimum was estimated to be 8.2 with both elastin-orcein and succinyl-ala3 p-nitroanilide as substra ... | 1994 | 8055953 |
| use of a phase variation-specific promoter of myxococcus xanthus in a strategy for isolating a phase-locked mutant. | the bacterium myxococcus xanthus alternates between two colony types distinguished by colony morphology and pigmentation. because the two phases are interconvertible, this phenomenon has been termed phase variation. in one phase, the colonies are bright yellow, rough, and swarming. in the alternate phase, the colonies are tan and mucoid with smooth edges. during exponential vegetative growth, the populations within a colony reach an equilibrium of approximately 99% yellow and 1% tan cells. neith ... | 1994 | 8071210 |
| increases in the intracellular concentration of glycerol during development in myxococcus xanthus s. courtney frasch. | the role of glycerol as a natural morphogen of myxospore formation in myxococcus xanthus was examined. glycerol was extracted from cells undergoing development and analyzed by gas chromatography. glycerol is present in cells, and the intracellular level undergoes a series of transient increases during development. the data suggest a role for glycerol in myxosporulation and fruiting body morphogenesis supporting the notion that this chemical induction of sporulation may represent a physiological ... | 1994 | 8076811 |
| nmr-derived three-dimensional solution structure of protein s complexed with calcium. | protein s is a developmentally-regulated ca(2+)-binding protein of the soil bacterium myxococcus xanthus. it functions by forming protective, multilayer spore surface assemblies which may additionally act as a cell-cell adhesive. protein s is evolutionarily related to vertebrate lens beta gamma-crystallins. | 1994 | 8081742 |
| territorial interactions between two myxococcus species. | it is unusual to find fruiting bodies of different myxobacteria occupying the same territory on natural samples. we were thus interested in determining whether myxobacteria establish territorial dominance and, if so, what the mechanism of that interaction is. we had previously observed that vegetative swarms of myxococcus xanthus and stigmatella aurantiaca placed close to each other on an agar surface initially merged but eventually separated. further studies indicated that these two species als ... | 1994 | 8106334 |
| the dsg gene of myxococcus xanthus encodes a protein similar to translation initiation factor if3. | the dsg mutants of myxococcus xanthus are defective in fruiting body development and sporulation, yet they grow normally. the deduced amino acid sequence of the dsg gene product is 50 and 51% identical to the amino acid sequence of translation initiation factor if3 of both escherichia coli and bacillus stearothermophilus, respectively. however, the dsg protein has a carboxy-terminal extension of 66 amino acids, which are absent from its e. coli and b. stearothermophilus homologs. the shine-dalga ... | 1994 | 8113184 |
| the myxococcus xanthus dsg gene product performs functions of translation initiation factor if3 in vivo. | the amino acid sequence of the dsg protein is 50% identical to that of translation initiation factor if3 of escherichia coli, the product of its infc gene. anti-e. coli if3 antibodies cross-react with the dsg protein. tn5 insertion mutations in dsg are lethal. when ample nutrients are available, however, certain dsg point mutant strains grow at the same rate as wild-type cells. under the starvation conditions that induce fruiting body development, these dsg mutants begin to aggregate but fail to ... | 1994 | 8113185 |
| sensory adaptation during negative chemotaxis in myxococcus xanthus. | myxococcus xanthus exhibits many tactic movements that require the frz signal transduction system, such as colony swarming and cellular aggregation during fruiting body formation. previously we demonstrated that the frz proteins control the chemotactic movements of m. xanthus (w. shi, t. köhler, and d. r. zusman, mol. microbiol. 9:601-611, 1993). however it was unclear from that study how chemotaxis might be achieved at the cellular level. in this study, we showed that m. xanthus cells not only ... | 1994 | 8113194 |
| unusual helix-containing greek keys in development-specific ca(2+)-binding protein s. 1h, 15n, and 13c assignments and secondary structure determined with the use of multidimensional double and triple resonance heteronuclear nmr spectroscopy. | multidimensional heteronuclear nmr spectroscopy has been used to determine almost complete backbone and side-chain 1h, 15n, and 13c resonance assignments of calcium loaded myxococcus xanthus protein s (173 residues). of the range of constant-time triple resonance experiments recorded, hncacb and cbca(co)nh, which correlate c alpha and c beta with backbone amide resonances of the same and the succeeding residue respectively, proved particularly useful in resolving assignment ambiguities created b ... | 1994 | 8117701 |
| identification of the myxococcus xanthus 59-kda membrane-associated gtp-binding protein as a proton-translocating atpase. | five gtp-binding proteins have been detected in myxococcus xanthus by photoaffinity cross-linking with azido-gtp [muñoz-dorado et al., j. biol. chem. 265 (1990a) 2702-2706]. one of them, the 59-kda membrane-associated gtp-binding protein, has been purified. the n-terminal sequence of a 10-kda fragment from the protease v8 digestion of the purified protein has been determined and degenerate oligodeoxyribonucleotides based on that sequence have been used to isolate and clone the gene that encodes ... | 1994 | 8125291 |
| evidence that asgb encodes a dna-binding protein essential for growth and development of myxococcus xanthus. | the asg mutants of myxococcus xanthus are defective in production of extracellular a-signal, which serves as a cell density signal for fruiting-body development. the dna sequence of asgb, one of the three asg genes, was determined. the deduced amino acid sequence of asgb contains a dna-binding helix-turn-helix motif near the c terminus. this putative helix-turn-helix is highly similar to the helix-turn-helix in region 4.2 of major sigma factors, which is the region that recognizes and interacts ... | 1994 | 8144470 |
| cloning and characterization of the soca locus which restores development to myxococcus xanthus c-signaling mutants. | the csga gene produces an intercellular signal during fruiting body formation of the myxobacterium myxococcus xanthus. sporulating pseudorevertants were isolated to allow us to understand the mechanism by which csga is perceived by cells and used to regulate developmental gene expression. two strains, ls559 and ls560, which have closely linked transposon insertions, soc-559 (formerly csp-559) and soc-560 (formerly csp-560), respectively, regained all the developmental behaviors lost by the csga ... | 1994 | 8157590 |
| incn plasmids mediate uv resistance and error-prone repair in pseudomonas aeruginosa pao. | while it seems likely that the ability to induce the expression of reca-controlled genes is nearly universal among the eubacteria, the expression of plasmid-borne ultraviolet (uv-resistance and mutagenesis genes seems to be species-dependent in a complex fashion. some plasmids encoding uv-resistance and mutagenesis functions only express these phenotypes in a select number of bacterial species. several uv-resistance plasmids that express these functions in escherichia coli are either unstable or ... | 1994 | 8162189 |
| structural similarity of a developmentally regulated bacterial spore coat protein to beta gamma-crystallins of the vertebrate eye lens. | the solution structure of ca(2+)-loaded protein s (m(r) 18,792) from the gram-negative soil bacterium myxococcus xanthus has been determined by multidimensional heteronuclear nmr spectroscopy. protein s consists of four internally homologous motifs, arranged to produce two domains with a pseudo-twofold symmetry axis, overall resembling a triangular prism. each domain consists of two topologically inequivalent "greek keys": the second and fourth motifs form standard greek keys, whereas the first ... | 1994 | 8183906 |
| cloning and characterization of the gene encoding the major sigma factor of stigmatella aurantiaca. | the gene (siga) encoding the major sigma factor of the myxobacterium, stigmatella aurantiaca, was cloned and sequenced. the deduced polypeptide contains 706 amino acids (aa) and has a deduced m(r) of 79,910. it exhibits four different aa sequence motifs which correlate with the conserved domains of the major sigma factors of myxococcus xanthus (sigma 80), escherichia coli (sigma 70) and bacillus subtilis (sigma 43). the sigma factor (sigma a) was detected in crude lysates of vegetative cells and ... | 1994 | 8200526 |
| the uraa locus and homologous recombination in mycobacterium bovis bcg. | molecular genetic manipulation of mycobacteria would benefit from the isolation of mycobacterial genes that could serve both as genetic markers and as sequences used to target homologous integration of recombinant dna into the genome. we isolated the mycobacterium bovis bcg gene encoding orotidine-5'-monophosphate decarboxylase (omp-dcase) by complementing an escherichia coli mutant defective in this activity. the bcg omp-dcase gene (uraa) and the flanking dna were sequenced. the predicted bcg o ... | 1993 | 8226675 |
| fatal attraction. | | 1993 | 8247147 |
| identification of esg, a genetic locus involved in cell-cell signaling during myxococcus xanthus development. | jd258, a tn5 insertion mutant of myxococcus xanthus, was shown to have major defects in three development-associated properties: expression of the developmentally regulated tps gene, spore formation, and production of multicellular fruiting bodies. the defects in tps gene expression and sporulation could be substantially corrected, at the phenotypic level, by mixing jd258 with wild-type cells (extracellular complementation). by this criterion, jd258 appeared to be a new member of a group of cond ... | 1993 | 8253664 |
| crystal structure of myxococcus xanthus nucleoside diphosphate kinase and its interaction with a nucleotide substrate at 2.0 a resolution. | the x-ray crystallographic structure of nucleoside diphosphate (ndp) kinase from myxococcus xanthus has been determined using multiple isomorphous replacement techniques and refined at 2.0 a resolution to a crystallographic r-factor of 0.17. this is the first report of the structure of an enzymatically active ndp kinase and of the enzyme with a bound nucleotide. the structure has been determined in p4(3)2(1)2 and i222 crystal forms. the enzyme monomer consists of a four-stranded antiparallel bet ... | 1993 | 8263923 |
| pim1 encodes a mitochondrial atp-dependent protease that is required for mitochondrial function in the yeast saccharomyces cerevisiae. | the pim1 nuclear gene in the yeast saccharomyces cerevisiae encodes a mitochondrial atp-dependent protease that exhibits over 30% identity with atp-dependent protease la from escherichia coli, lon from bacillus brevis, and one from myxococcus xanthus. in addition, pim1 is 1133 amino acids long and has a putative mitochondrial import signal in the n-terminal region. enzymatic comparisons of normal pim1+ and deficient pim1-delta strains revealed that the atp-dependent protease is located within th ... | 1994 | 8276800 |
| isolation and phenotypic characterization of myxococcus xanthus mutants which are defective in sensing negative stimuli. | myxococcus xanthus is a gram-negative gliding bacterium that exhibits a complex life cycle. exposure of m. xanthus to chemicals like dimethyl sulfoxide (dmso) at nondeleterious concentrations or the depletion of nutrients caused several negative responses by the cells. dmso (> 0.1 m) or nutrient depletion triggered a repellent response: cell swarming was inhibited and frzcd (a methyl-accepting chemotaxis protein) was demethylated; higher concentrations of dmso (> 0.3 m) or prolonged starvation i ... | 1994 | 8300525 |
| mutations in two new loci that impair both extracellular protein production and development in myxococcus xanthus. | two transposon insertion mutants of myxococcus xanthus altered in the secretion of protein as determined by the hydrolytic activities of several enzymes during vegetative growth were also unable to complete fruiting body formation and were severely impaired in sporulation. the insertions were located in the same part of the m. xanthus chromosome but were unlinked by transduction and therefore define two distinct loci, called exca and excb. since both exc +/- mutants were able to rescue developme ... | 1993 | 8320239 |
| myxococcus xanthus encodes an atp-dependent protease which is required for developmental gene transcription and intercellular signaling. | the bsga gene of myxococcus xanthus plays an essential role in the regulation of early gene expression during fruiting body formation and sporulation. bsga mutants behave as though unable to initiate a required cell-cell interaction and consequently fail to transcribe normal levels of many developmentally induced genes. we determined the nucleotide sequence of bsga, which predicts a single gene encoding a 90.4-kda protein. the deduced bsga protein shares 45 and 48% amino acid identity with the l ... | 1993 | 8331082 |
| the lond gene is homologous to the lon gene encoding an atp-dependent protease and is essential for the development of myxococcus xanthus. | myxococcus xanthus contains two genes (lonv and lond) homologous to the escherichia coli lon gene for an atp-dependent protease. we found that the lond gene encodes a 90-kda protein consisting of 827 amino acid residues. the lond gene product shows 49, 48, and 52% sequence identity to the products of the m. xanthus lonv, e. coli lon, and bacillus brevis lon genes, respectively. when a lond-lacz fusion was used, lond was expressed during both vegetative growth and development. however, while lond ... | 1993 | 8331083 |
| oar, a 115-kilodalton membrane protein required for development of myxococcus xanthus. | myxococcus xanthus is a developmental gram-negative bacterium which forms multicellular fruiting bodies upon nutrient starvation. this bacterium was found to contain a 115-kda membrane protein which separated with the inner membrane fraction by sucrose density gradient centrifugation. the gene for this protein was cloned, and its dna sequence was determined. the deduced amino acid sequence consists of 1,061 residues. this protein contains a putative signal sequence and many short segments, found ... | 1993 | 8335633 |
| frzcd, a methyl-accepting taxis protein from myxococcus xanthus, shows modulated methylation during fruiting body formation. | the frizzy (frz) genes of myxococcus xanthus are required to control directed motility during vegetative growth and fruiting body formation. frzcd, a protein homologous to the methyl-accepting chemotaxis proteins from enteric bacteria, is modified by methylation in response to environmental conditions. transfer of cells from rich medium to fruiting medium initially caused rapid demethylation of frzcd. subsequently, the amount of frzcd increased, but most remained unmethylated. at about the time ... | 1993 | 8335650 |
| spatial restriction of cellular differentiation. | myxococcus xanthus cells differentiate into myxospores within a fruiting body, an aggregate of approximately 10(5) cells. previous work had discerned an inner and outer domain within the fruiting body differentiated by cell density and cell alignment. to test whether the two domains might play different roles in spore differentiation, developmentally regulated gene fusions were screened for expression restricted to one domain or the other. transcriptional lacz fusions to 80 developmentally regul ... | 1993 | 8370517 |
| autophosphorylation of nucleoside diphosphate kinase from myxococcus xanthus. | the nucleoside diphosphate kinase (ndp kinase) from myxococcus xanthus has been purified to homogeneity and crystallized (j. munoz-dorado, m. inouye, and s. inouye, j. biol. chem. 265:2702-2706, 1990). in the presence of atp, the ndp kinase was autophosphorylated. phosphoamino acid analysis was carried out after acid and base hydrolyses of phosphorylated ndp kinase. it was found that the protein was phosphorylated not only at a histidine residue but also at a serine residue. replacement of histi ... | 1993 | 8381783 |
| light-induced carotenogenesis in myxococcus xanthus: genetic analysis of the carr region. | carotenogenesis is light-inducible in the non-photosynthetic, gram-negative, bacterium myxococcus xanthus. we report the characterization of the carr region which controls this phenomenon. insertion of transposon tn5 close to the carr region caused a dominant, carotenoid-constitutive mutation because of the presence of a constitutive, outward-reading promoter in the is50l component of tn5. in wild-type cells, a powerful, tightly-regulated, light-inducible promoter directs the transcription of tw ... | 1993 | 8384685 |
| the mgla component of the binding protein-dependent galactose transport system of salmonella typhimurium is a galactose-stimulated atpase. | binding protein-dependent transport systems mediate the accumulation of several ions, sugars, amino acids, and peptides in gram-negative bacteria by using the energy of atp hydrolysis and belong to a superfamily of membrane proteins which extends to eukaryotic cells and includes the multidrug resistance p-glycoprotein and the cystic fibrosis transmembrane conductance regulator. the binding protein-dependent galactose transport system of salmonella typhimurium comprises four proteins which have b ... | 1993 | 8387496 |
| beta-galactosidase activity in single differentiating bacterial cells. | myxococcus xanthus strains containing transcriptional fusions to lacz were analyzed and fractionated by differences in their levels of beta-galactosidase expression. the fluorogenic substrate for beta-galactosidase, fluorescein di-beta-galactopyranoside, was introduced into m. xanthus cells during a rapid decrease in osmolarity of the medium followed by a return to isoosmolarity. fluorescein, the product of hydrolysis, was retained within the cells and their viability was preserved. fluorescence ... | 1993 | 8396263 |
| isoprenoid biosynthesis in bacteria: two different pathways? | the biosynthesis of isopentenylpyrophosphate, a central intermediate of isoprenoid formation, was investigated in six different bacterial organisms. cell-free extracts of myxococcus fulvus, staphylococcus carnosus, lactobacillus plantarum and halobacterium cutirubrum converted [14c]acetyl-coa or [14c]hydroxymethylglutaryl-coa to [14c]mevalonic acid. furthermore, [14c]mevalonic acid, [14c]mevalonate-5-phosphate and [14c]mevalonate-5-pyrophosphate were metabolized to [14c]isopentenylpyrophosphate. ... | 1993 | 8405922 |
| chemotaxis plays a role in the social behaviour of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium that glides on a solid surface and displays a wide range of social behaviour including microbial development. the frz genes are homologues to the chemotaxis genes of escherichia coli and salmonella typhimurium and have been shown to be involved in microbial development. however, chemotaxis has never been clearly demonstrated in myxococcus. in this study, we showed that m. xanthus exhibited tactic movements to many chemicals when they were subjected ... | 1993 | 8412706 |
| eukaryotic-like protein serine/threonine kinases in myxococcus xanthus, a developmental bacterium exhibiting social behavior. | myxococcus xanthus, a gram-negative bacterium exhibits a spectacular life cycle and social behavior. its developmental cycle and multicellular morphogenesis resemble those of eukaryotic slime molds such as dictyostelium discoideum. on the basis of this resemblance, we explored the existence of eukaryotic-like protein serine/threonine kinases which are known to play important roles in signal transduction during development of d. discoideum. it was indeed found that m. xanthus contains a large fam ... | 1993 | 8432741 |
| growth phase dependence of the activation of a bacterial gene for carotenoid synthesis by blue light. | myxococcus xanthus responds to blue light by producing carotenoid pigments. a mutation at a gene named carc is known to block the metabolism of phytoene, a carotenoid precursor, and this gene has now been cloned and sequenced. we show here that gene carc, which is homologous to phytoene dehydrogenase genes from other organisms, is tightly regulated by light through a mechanism that operates only when the cells have reached the stationary phase or are starved of a carbon source. a genetic element ... | 1993 | 8467787 |
| cloning and nucleotide sequence of the myxococcus xanthus lon gene: indispensability of lon for vegetative growth. | the lon gene of escherichia coli is known to encode protease la, an atp-dependent protease associated with cellular protein degradation. a lon gene homolog from myxococcus xanthus, a soil bacterium which differentiates to form fruiting bodies upon nutrient starvation, was cloned and characterized by use of the lon gene of e. coli as a probe. the nucleotide sequence of the m. xanthus lon gene was determined. it contains an open reading frame that encodes a 92-kda protein consisting of 817 amino a ... | 1993 | 8468287 |