Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| deoxyribonucleic acid homology in bacterial taxonomy: effect of incubation temperature on reaction specificity. | parameters affecting deoxyribonucleic acid duplex (dna-dna) formation on membrane filters were evaluated. the reference strains used were cytophaga succinicans strain 8, which has a guanine plus cytosine (gc) content of 38%, and myxococcus xanthus strain fb, which has a gc content of 70%. both organisms are gliding bacteria classified among the myxobacteria. among the parameters evaluated, the incubation temperature used during duplex formation was found to be the most important in terms of the ... | 1968 | 4966832 |
| changes in activity of glyoxylate cycle enzymes during myxospore development in myxococcus xanthus. | activities of the glyoxylate cycle enzymes isocitrate lyase (ec 4.1.3.1) and malate synthase (ec 4.1.3.2) were assayed in extracts prepared at different stages of myxospore formation in liquid cultures of myxococcus xanthus. activities of both enzymes attained peak values during conversion of rods to spheres. isocitrate lyase activity decreased after reaching its peak value. malate synthase activity also declined but at a much slower rate. the loss of isocitrate lyase activity could be prevented ... | 1972 | 5053882 |
| bacteriophage infection of myxococcus xanthus during cellular differentiation and vegetative growth. | 1972 | 5063429 | |
| myxospore formation in myxococcus xanthus: chemical changes in the cell wall during cellular morphogenesis. | vegetative cells of myxococcus xanthus (strain fb) were induced to form myxospores by the glycerol induction technique. several structural changes took place in the peptidoglycan during myxospore formation. the percent of the peptidoglycan comprised of monomer (disaccharide peptide) decreased from about 20% to approximately 7%. the proportion of the total diaminopimelic acid possessing a free amino group decreased about 11%. a carbohydrate containing only glucose was found to be bound, possibly ... | 1972 | 5086662 |
| the identification of 3-o-methyl-d-xylose and 3-o-methyl-l-xylose as constituents of the lipopolysaccharides of myxococcus fulvus and rhodopseudomonas viridis, respectively. | 1971 | 5138643 | |
| [lytic action of myxococcus xanthus beebe on various phytopathogenic bacteria]. | 1971 | 5290797 | |
| stable messenger ribonucleic acid and germination of myxococcus xanthus microcysts. | we have examined germination, protein synthesis and ribonucleic acid (rna) synthesis by microcysts of the fruiting myxobacterium myxococcus xanthus. the morphological aspects of microcyst formation were completed at about 2 hr after induction had begun. in such microcysts, germination, rna synthesis, and protein synthesis were inhibited by actinomycin d (act d). at 6 hr after induction, germination and protein synthesis had become relatively resistant to act d, whereas rna synthesis was inhibite ... | 1970 | 5413824 |
| dna cycle of myxococcus xanthus. | 1970 | 5453346 | |
| ribonucleic acid synthesis during microcyst formation in myxococcus xanthus: characterization by deoxyribonucleic acid-ribonucleic acid hybridization. | the technique of deoxyribonucleic acid-ribonucleic acid (rna) hybridization was used to compare the rna synthesized during vegetative growth and microcyst formation in myxococcus xanthus. all classes of rna, including ribosomal rna, were synthesized during microcyst formation. the results indicate that the ribosomal rna synthesized during microcyst formation was indistinguishable from that made during vegetative growth. hybridization competition experiments demonstrated that certain messenger rn ... | 1970 | 5473896 |
| potassium uptake during microcyst formation in myxococcus xanthus. | the kinetics of (42)k uptake by myxococcus xanthus during vegetative growth and microcyst formation were determined. in the medium studied, growing cells concentrated potassium about 100-fold, yielding an intracellular concentration of 147 mm. the influx of k(+) in growing cells was 17 +/- 3 pmoles of k(+)/cm(2) min. about 5 hr after induction of vegetative cells to microcysts, the k(+) influx decreased and the intracellular concentration fell. by 18 hr after induction, there was no measurable i ... | 1970 | 5473918 |
| fine structure of bacteriophage-infected myxococcus xanthus. 1. the lytic cycle in vegetative cells. | 1971 | 5543277 | |
| increase in glyoxylate shunt enzymes during cellular morphogenesis in myxococcus xanthus. | 1971 | 5548316 | |
| division cycle of myxococcus xanthus. ii. kinetics of stable and unstable ribonucleic acid synthesis. | the kinetics of stable and unstable ribonucleic acid (rna) synthesis during the division cycle of myxococcus xanthus growing in a defined medium was determined. under these conditions, m. xanthus contains one chromosome which is replicated during 80% of the cell cycle. stable rna synthesis was measured by pulselabeling an exponential-phase culture with radioactive uridine and then preparing the cells for quantitative autoradiography. by measuring the size of individual cells as well as the numbe ... | 1971 | 5555557 |
| the physical organization of the cytoplasm in myxococcus zanthus and the fine structure of its components. | 1967 | 5601021 | |
| nutritional induction and suppression of fruiting in myxococcus xanthus fba. | a defined agar medium (a agar) containing 15 amino acids in concentrations between 0.5 and 2 mm was developed for studying the fruiting cycle of myxococcus xanthus fba. cells grew only vegetatively in this medium unless the initial concentration of one of nine required or stimulatory amino acids was lowered about 50-fold. in the latter circumstance, fruiting bodies developed after several days of vegetative growth. the conclusion was that fruiting occurred when any amino acid required for normal ... | 1968 | 5643044 |
| peptidoglycan of myxococcus xanthus: structure and relation to morphogenesis. | the chemical nature and distribution of the peptidoglycan in myxococcus xanthus at various stages of the cellular life cycle were investigated. vegetative cells and microcysts contained approximately 0.6% by weight of peptidoglycan. the overall composition of the peptidoglycan was similar in both cell types and was approximately 1 glutamic acid, 1 diaminopimelic acid, 1.7 alanine, 0.75 n-acetylglucosamine, and 0.75 n-acetylmuramic acid. (we have assumed that all the hexosamines are n-acetylated. ... | 1968 | 5669896 |
| microcyst germination in myxococcus xanthus. | germination of glycerol-prepared microcysts of myxococcus xanthus was studied. the sequence of morphological events during germination resembled that of germinating fruiting body-microcysts. the turbidity drop of a culture of germinating microcysts could be described by mccormick's formula derived for germinating bacillus spores. the rate of uptake of labeled glycine and acetate did not change during germination. temperature, aeration, and ph optima for germination were the same as for vegetativ ... | 1968 | 5669898 |
| deoxyribonucleic acid synthesis during microcyst germination in myxococcus xanthus. | deoxyribonucleic acid (dna) synthesis was measured during microcyst germination in myxococcus xanthus by radioactive thymidine incorporation, autoradiography, and chemical analysis. microcysts contained an average of 6.6 conserved units of dna, corresponding to 3 to 4 chromosomes per cell. correlation of the dna content and chromosome number of microcysts indicated that the molecular weight of the nonreplicating m. xanthus chromosome is 4.9 x 10(9) daltons. dna synthesis was initiated 3.5 to 4 h ... | 1968 | 5686021 |
| structural changes in stigmatella aurantiaca during myxospore induction. | suspension cultures of stigmatella aurantiaca (chondromyces aurantiacus) were induced to form myxospores by addition of glycerol to the growing culture. the cells were fixed at various stages during conversion, thin sections were prepared, and changes in fine structure were studied. vegetative cells are quite similar in their ultrastructure to myxococcus xanthus. during transformation into myxospores, three important cytological changes were observed. granules of storage material, probably polys ... | 1969 | 5773035 |
| action spectrum for carotenogenesis in myxococcus xanthus. | an action spectrum was measured for photoinduction of colored carotenoids in dark-grown, early stationary-phase cells of myxococcus xanthus. maximum activity was observed at 405 to 410 nm with subsidiary maxima at 512, 533, 548, 585, and 635 nm. these maxima correspond closely in position and magnitude with absorption maxima of protoporphyrin ix, which had previously been isolated from m. xanthus cells and had been shown to increase during the stationary phase of the culture. late stationary-pha ... | 1969 | 5776523 |
| deoxyribonucleic acid homology among the fruiting myxobacteria. | deoxyribonucleic acid similarities were determined by competition experiments. the several strains of fruiting myxobacteria tested showed from 23 to 89% homology with the reference strains myxococcus xanthus (fb) and m. fulvus (m6). | 1969 | 5781583 |
| resistance of vegetative cells and microcysts of myxococcus xanthus. | the resistance of vegetative cells and of microcysts of myxococcus xanthus to several destructive agents was compared. fruiting-body microcysts were 300 times more resistant to 60 c, 5.4 times more resistant to ultraviolet light, and 19.3 times more resistant to sonic vibration than were vegetative cells. whereas resistance to sonic vibration developed during the conversion of rods to refractile spheres, resistance to heat did not appear until after the conversion was complete. both vegetative c ... | 1969 | 5788715 |
| action spectrum for the photolysis of myxococcus xanthus. | 1966 | 5894228 | |
| induction of cellular morphogenesis in myxococcus xanthus. i. general description. | dworkin, martin (university of minnesota, minneapolis), and william sadler. induction of cellular morphogenesis in myxococcus xanthus. i. general description. j. bacteriol. 91:1516-1519. 1966.-the details of a process for converting vegetative rods of myxococcus xanthus to microcysts rapidly (120 min), quantitatively, and synchronously are presented. the conversion is induced by 0.5 m glycerol. on the basis of a number of morphological and physiological parameters, the microcysts thus produced a ... | 1966 | 5929775 |
| induction of cellular morphogenesis in myxococcus xanthus. ii. macromolecular synthesis and mechanism of inducer action. | sadler, william (university of minnesota, minneapolis), and martin dworkin. induction of cellular morphogenesis in myxococcus xanthus. ii. macromolecular synthesis and mechanism of inducer action. j. bacteriol. 91:1520-1525. 1966.-net changes in ribonucleic acid (rna), deoxyribonucleic acid (dna), and protein syntheses in cells of myxococcus xanthus during induced, synchronous conversion to microcysts are described. the net synthesis of all three macromolecules was temporarily halted for a brief ... | 1966 | 5929776 |
| light-induced lysis and carotenogenesis in myxococcus xanthus. | burchard, robert p. (university of minnesota, minneapolis), and martin dworkin. light-induced lysis and carotenogenesis in myxococcus xanthus. j. bacteriol. 91:535-545. 1966.-myxococcus xanthus, grown vegetatively in the light, developed an orange carotenoid after the cells entered stationary phase of growth; pigment content increased with age. cells grown in the dark did not develop carotenoid and could be photolysed by relatively low-intensity light only during stationary phase; rate of photol ... | 1966 | 5935340 |
| a bacteriophage for myxococcus xanthus: isolation, characterization and relation of infectivity to host morphogenesis. | burchard, robert p. (university of minnesota, minneapolis), and m. dworkin. a bacteriophage for myxococcus xanthus: isolation, characterization and relation of infectivity to host morphogenesis. j. bacteriol. 91:1305-1313. 1966.-a bacteriophage (mx-1) infecting myxococcus xanthus fb(t) has been isolated from cow dung. the bacteriophage particle is approximately 175 mmu long. a tail about 100 mmu in length is encased in a contractile sheath and terminates in a tail plate. the head is polyhedral w ... | 1966 | 5948779 |
| lytic enzyme produced by myxococcus xanthus. | hart, beth a. (cornell university, ithaca, n.y.), and stanley a. zahler. lytic enzyme produced by myxococcus xanthus. j. bacteriol. 92:1632-1637. 1966.-strain fba of myxococcus xanthus releases into its culture medium an enzyme capable of lysing micrococcus lysodeikticus cells and of releasing n-acetyl amino sugars from their cell walls. the lysin is stable at ph values near neutrality and at temperatures below 50 c. it lyses a number of bacterial species sensitive to egg-white lysozyme, and fai ... | 1966 | 5958103 |
| the "polyphosphate overplus" phenomenon in myxococcus xanthus and its influence on the architecture of the cell. | 1966 | 5989427 | |
| the fate of the cell envelopes of myxococcus xanthus during microcyst germination. | 1966 | 5990745 | |
| deoxyribonucleic acid synthesis during exponential growth and microcyst formation in myxococcus xanthus. | myxococcus xanthus in exponential phase with a generation time of 270 min contained a period of 50 min during which deoxyribonucleic acid (dna) synthesis did not take place. after induction of microcysts by the glycerol technique, the dna content increased 19%. autoradiographic experiments demonstrated that the dna made after glycerol induction was not evenly distributed among the microcysts. the distribution of grains per microcyst fits the following model of chromosome replication: in exponent ... | 1967 | 6032514 |
| ribonucleic acid synthesis during morphogenesis in myxococcus xanthus. | ribonucleic acid synthesis was measured during the morphogenesis of myxococcus xanthus. after induction of microcyst formation by the addition of glycerol to an exponential culture, net ribonucleic acid (rna) synthesis was immediately terminated (measured either chemically or by the accumulation of acid-insoluble radioactivity). extensive rna turnover did take place, however, including rna made both before and after induction. sucrose gradient centrifugation revealed that ribosomes and ribosomal ... | 1967 | 6074398 |
| multicopy single-stranded dna isolated from a gram-negative bacterium, myxococcus xanthus. | a gram-negative bacterium, myxococcus xanthus, was found to contain 500 to 700 copies per chromosome of a short single-stranded linear dna fragment. when this dna (multicopy single-stranded dna; msdna) labeled at the 5' end with kinase was used as a probe against total chromosomal blots, it hybridized to unique high molecular weight bands, which were cloned and sequenced. labeling of msdna was also possible using the klenow fragment of dna polymerase i as well as terminal deoxynucleotidyl transf ... | 1984 | 6088065 |
| construction of tn5 lac, a transposon that fuses lacz expression to exogenous promoters, and its introduction into myxococcus xanthus. | a promoterless trp-lac fusion fragment was inserted near one end of the bacterial transposon tn5 in the correct orientation to fuse lacz gene expression to promoters outside tn5. the resulting transposon, tn5 lac, retains the kanamycin-resistance gene of tn5 and transposes in escherichia coli at 6% the frequency of tn5 to many different sites in a bacteriophage lambda target. expression of beta-galactosidase, the product of the lacz gene, from tn5 lac insertions in phage lambda depends both on i ... | 1984 | 6091110 |
| patterns of protein production in myxococcus xanthus during spore formation induced by glycerol, dimethyl sulfoxide, and phenethyl alcohol. | spore formation of myxococcus xanthus can occur not only on agar plates during fruiting body formation, but also in a liquid culture by simply adding glycerol, dimethyl sulfoxide, or phenethyl alcohol to the culture. this chemically-induced spore formation occurs synchronously and much faster than that occurring during fruiting body formation. dramatic changes in patterns of protein synthesis were observed during chemically-induced spore formation, as had previously been observed during fruiting ... | 1980 | 6160140 |
| ribonucleic acid synthesis during fruiting body formation in myxococcus xanthus. | a method has been devised that allowed us, for the first time, to pulse-label m. xanthus cells with precursors for ribonucleic acid biosynthesis while they were undergoing fruiting body formation. using this method, we examined patterns of ribonucleic acid (rna) accumulation throughout the process of fruiting body formation. as development proceeded, the rate of rna accumulation increased at two periods of the developmental cycle: once just before aggregation and once late in the cycle, when spo ... | 1981 | 6163763 |
| binding properties of myxobacterial hemagglutinin. | the nature of the receptor for myxobacterial hemagglutinin (mbha) on the outer surface of myxococcus xanthus was investigated by studying the binding of 125i-mbha to vegetative and developmental cells. the amount of binding and hence the number of binding sites/cell appeared to increase 4-fold during development to 2.1 x 10(4) sites/cell. furthermore, the apparent association constant (ka) for mbha increased 3-fold to 3 x 10(7) m-1. fetuin, a glycoprotein which binds mbha, blocked the binding of ... | 1981 | 6170645 |
| gene expression during development of myxococcus xanthus. analysis of the genes for protein s. | protein s is an abundant spore coat protein produced during fruiting body formation (development) of the bacterium myxococcus xanthus. we have cloned the dna which codes for protein s and have found that this dna hybridizes to three protein s rna species from developmental cells but does not hybridize to rna from vegetative cells. the half-life of protein s rna was found to be unusually long, about 38 minutes, which, at least in part, accounts for the high level of protein s synthesis observed d ... | 1984 | 6204058 |
| purine-containing compounds, including cyclic adenosine 3',5'-monophosphate, induce fruiting of myxococcus xanthus by nutritional imbalance. | induction of myxococcus xanthus fruiting by a number of different purine-containing compounds, including cyclic adenosine 3',5'-monophosphate, is defective in a mutant resistant to 2,6-diaminopurine. furthermore, the purine-induced fruiting of wild-type cultures is uniquely blocked by a low concentration of added glycine. these results imply that different purine-containing compounds induce fruiting through a single mechanism involving nutritional imbalance. | 1980 | 6243625 |
| recovery of quenched radioactivity from thin-layer chromatographic plates. an improved assay for cgmp phosphodiesterase in myxococcus xanthus. | ammonium bicarbonate was found useful in extracting a variety of radiolabeled compounds from thin-layer chromatographic plates. the technique significantly increased the sensitivity of the assay for cyclic nucleotide phosphodiesterases. this method was used to show unequivocally, the presence of cgmp phosphodiesterase in vegetative cells of myxococcus xanthus. | 1980 | 6252204 |
| cyclic adenosine 3',5'-monophosphate binding protein in developing myxospores of myxococcus xanthus. | the interaction of cyclic adenosine 3',5'-monophosphate (camp) with specific protein molecules was examined in the high-speed supernatant fraction of extracts made at stages throughout glycerol-induced myxospore development in myxococcus xanthus. experiments using 8-azido[32p]camp, a photoaffinity analogue of camp, and sds - polyacrylamide gel electrophoresis showed that the nucleotide interacts with only a single protein band of 12 500 molecular weight. both the identiy and amount of this prote ... | 1980 | 6257359 |
| reexamination of the genome size of myxobacteria, including the use of a new method for genome size analysis. | the genome sizes of two myxobacteria, myxococcus xanthus and stigmatella aurantiaca, were measured by renaturation analysis and also by a new method involving the quantitation of individual restriction fragments. in contrast to several previous reports, which indicate that m. xanthus has a genome size which is three to four times that of escherichia coli, the present measurements indicated that the m. xanthus genome is only about 24 to 53% larger than that of e. coli. s. aurantiaca had a genome ... | 1981 | 6259127 |
| genetic characterization of aggregation-defective developmental mutants of myxococcus xanthus. | the transposon tn5 was used to map temperature-sensitive mutants of myxococcus xanthus defective in aggregation (c. e. morrison and d. r. zusman, j. bacteriol. 140:1036-1042, 1979). seven of the eight mutants showing a similar terminal phenotype (rough) were found to be tightly linked. these mapped in a group of loci which we have designated aggr1, aggr2, aggr3, and aggr4. temperature-sensitive mutants having a different terminal phenotype were not liked to aggr. a search through a group of nonc ... | 1981 | 6268606 |
| "frizzy" mutants: a new class of aggregation-defective developmental mutants of myxococcus xanthus. | during fruiting-body formation in myxococcus xanthus, cells aggregate into raised mounds, where they sporulate. a new class of aggregation-defective developmental mutants was identified within a collection of nonfruiting mutants of m. xanthus. the mutants failed to aggregate into discrete mounds, but rather aggregated into "frizzy" filaments. many cells within the filaments sporulated normally. pairwise mixtures of representative frizzy mutants were unable to stimulate each other to aggregate no ... | 1982 | 6281244 |
| tandem repeat of the genes for protein s, a development-specific protein of myxococcus xanthus. | protein s, a development-specific protein of myxococcus xanthus is produced only during fruiting body formation. more than 15% of total protein synthesis during this period is accounted for by the production of protein s. the genes for protein s were identified and cloned with the use of mixed probes consisting of eight synthetic oligodeoxyribonucleotides (tetradecamers) which correspond to a carboxyl-terminal portion of protein s. the two genes are oriented in the same direction and are separat ... | 1983 | 6294106 |
| coliphage p1-mediated transduction of cloned dna from escherichia coli to myxococcus xanthus: use for complementation and recombinational analyses. | we have found that coliphage p1 can be used to transduce cloned dna from escherichia coli to myxococcus xanthus. transduction occurred at a high efficiency, and no evidence for dna restriction was observed. the analysis of the transductants showed that they fall into three general categories: (i) haploid cells which contain portions of the cloned dna substituted for homologous chromosomal dna; (ii) heterozygous merodiploids which contain the recombinant plasmid integrated into the chromosome at ... | 1983 | 6305916 |
| insertions of tn5 near genes that govern stimulatable cell motility in myxococcus. | insertions of transposon tn5 were used to examine the genetics of motility mutants in myxococcus. fifteen independent insertions of tn5 were isolated that were linked to seven different loci that govern motility. among the motility mutants that can be stimulated to move transiently by contact with other cells, a one-to-one correspondence was confirmed between specificity of stimulation and genetic locus. there are six different specificities and six corresponding loci, as if each locus governs a ... | 1983 | 6306258 |
| construction of tandem genetic duplications with defined endpoints in myxococcus xanthus. | 1983 | 6310346 | |
| in situ transposon replacement and isolation of a spontaneous tandem genetic duplication. | using a specialized transducing p1 phage carrying an insertion of tn5-132, an insertion of tn5-wt in the chromosome of myxococcus xanthus, which codes for resistance to kanamycin, can be replaced with one of tn5-132, which codes for resistance to tetracycline. that tn5-132 in the daughter is inserted at the same location in the chromosome as tn5-wt was in the parent was shown by a variety of physical and genetic tests. southern blot hybridizations of restriction digests of daughter and parent dn ... | 1983 | 6310351 |
| structural similarities between the development-specific protein s from a gram-negative bacterium, myxococcus xanthus, and calmodulin. | during differentiation of myxococcus xanthus, a large amount of protein s is produced and assembled on the surface of the myxospore by a process that specifically requires ca2+. the gene for protein s has been cloned, and two tandemly repeated homologous genes have been found to be within a short distance of each other in the m. xanthus chromosome. we determined the dna sequence of 3,692 bp encompassing both genes and deduced the amino acid sequences of the two gene products. the gene 1 (upstrea ... | 1983 | 6316328 |
| two-dimensional s1 nuclease heteroduplex mapping: detection of rearrangements in bacterial genomes. | a method of two-dimensional s1 nuclease heteroduplex mapping was developed to detect gene rearrangements and repeated sequences in total bacterial chromosomes. to detect dna rearrangements between two variant bacterial strains, total chromosomal dna preparations from the two strains are digested with four-base-recognizing restriction enzymes, mixed together, denatured, renatured, and separated on first-dimension polyacrylamide slab gels. gel strips are cut out and soaked in a buffer containing s ... | 1984 | 6326139 |
| effects of deletion of the gene for the development-specific protein s on differentiation in myxococcus xanthus. | a deletion mutation of the gene for protein s (tps), a development-specific protein of myxococcus xanthus, was constructed. no significant differences in the process of fruiting body formation or the yield of myxospores were observed between mutant and wild-type cells. on the other hand, when the tps gene was deleted together with a 2.0-kilobase sequence including the ops gene immediately upstream of the tps gene, fruiting body formation was substantially delayed, and the yield of myxospores was ... | 1984 | 6327634 |
| an inhibitor of mitochondrial respiration which binds to cytochrome b and displaces quinone from the iron-sulfur protein of the cytochrome bc1 complex. | myxothiazol, an antibiotic from myxococcus fulvus, which inhibits mitochondrial respiration in the bc1 complex of the respiratory chain, has effects on the redox components of isolated succinate-cytochrome c reductase complex which suggest that it interacts with both cytochrome b and the iron-sulfur protein of the bc1 complex. the inhibitor appears to increase the midpoint potentials of cytochromes b-562 and b-566, as indicated by an increase in their reducibility by the succinate/fumarate coupl ... | 1984 | 6327677 |
| developmental cell interactions of myxococcus xanthus: analysis of mutants. | a set of developmental mutants have been examined that behave as if defective in cellular interactions necessary for the formation of myxospores during fruiting body development. sporulation is rescued in these mutants if they are mixed with wild-type cells. complementation experiments with whole cells divide the mutants into four groups (a, b, c, and d). mutants of group a appear to be less responsive to starvation, a condition that normally initiates development. mutants of group d respond to ... | 1983 | 6402495 |
| evidence for long-lived mrna during fruiting body formation in myxococcus xanthus. | half-lives of myxococcus xanthus mrna were determined by inhibiting rna polymerase with rifampin and then measuring the rate of [35s]methionine incorporation into protein. vegetative cells resuspended in clone fruiting liquid culture showed an average mrna half-life of approximately 3.5 min. developmental cells (24 or 48 hr) exhibited biphasic decay curves with apparent mrna half-lives of approximately 3.5 min and 20-30 min. the more-stable mrna species accounted for about 30% of all mrna presen ... | 1983 | 6402782 |
| myxococcus xanthus does not respond chemotactically to moderate concentration gradients. | using a number of approaches we were unable to demonstrate a chemotactic response of myxococcus xanthus to a variety of defined and complex materials. these data in addition to a number of prima facie arguments considerably reduce the likelihood that m. xanthus possesses a mechanism for chemotactic behavior. | 1983 | 6403510 |
| tactic behavior of myxococcus xanthus. | with time-lapse videomicroscopy it was demonstrated that cells of myxococcus xanthus are capable of directed (tactic) movement toward appropriate targets. mutants that had lost a motility (j. hodgkin and d. kaiser, mol. gen. genet. 171:177-191, 1979) were unable to show directed movement. cells showed directed movement to polystyrene latex beads and to glass beads, as well as to clumps of micrococcus luteus. this is consistent with other observations in an accompanying paper (m. dworkin and d. e ... | 1983 | 6403511 |
| transport and localization of protein s, a spore coat protein, during fruiting body formation by myxococcus xanthus. | protein s, the most abundant soluble protein synthesized by myxococcus xanthus fb during early fruiting body formation, accumulates in the soluble fraction of developing cells, reaching a peak at about 24 h; at late stages of fruiting body formation, protein s is found on the surface of spores (m. inouye et al. proc. natl. acad. sci. u.s.a. 76:209-213, 1979). in this study, the transport and localization of protein s were investigated. cells were fractionated to give osmotic shock, membrane, cyt ... | 1983 | 6404884 |
| genetic and physical characterization of lysogeny by bacteriophage mx8 in myxococcus xanthus. | myxophage mx8 can initiate a lysogenic cycle in myxococcus xanthus. the lysogenic phage was gentically stable in vegetative cells and persisted in the latent state through many cell generations in the absence of extracellular phage reinfection. the latent state also was stable during the host developmental cycle, since myxospores transmitted latent mx8 genetic information to future progeny cells. dna hybridization experiments to probe the structure of the lysogenic phage provided physical eviden ... | 1983 | 6404885 |
| iodination of myxococcus xanthus during development. | intact cells of myxococcus xanthus were iodinated with [125i]lactoperoxidase to permit examination of the surface components accessible to labeling during cell development. vegetative cells, starved on a defined solid medium, aggregated, formed fruiting bodies, and produced myxospores. cells collected at different stages were iodinated, and their proteins were analyzed by one- and two-dimensional electrophoresis and autoradiography. one-dimensional electrophoresis revealed six iodinated bands in ... | 1983 | 6411682 |
| surface tension gradients: feasible model for gliding motility of myxococcus xanthus. | we propose that surface tension is the driving force for the gliding motility of myxococcus xanthus. our model requires that the cell be able to excrete surfactant in a polar and reversible fashion. we present calculations that (i) estimate the surface tension difference across a cell necessary to move the cell at the observed rate, which is less than 10(-5) dyn/cm, an extremely small value; (ii) estimate the rate of surfactant excretion necessary to produce the required surface tension differen ... | 1983 | 6411689 |
| experimental observations consistent with a surface tension model of gliding motility of myxococcus xanthus. | we have presented experimental evidence to support the model that gliding motility of myxococcus xanthus is driven by surface tension. (i) motility is inhibited by the addition of sufficient exogenous, nontoxic surfactants to swamp out the cells' own surfactant gradient. (ii) m. xanthus does not move polystyrene latex beads over its surface. (iii) motility is prevented by elimination of an interfacial surface tension either by embedding the cells in soft agar or by placing them at an agar-aqueou ... | 1983 | 6411690 |
| the myxalamids, new antibiotics from myxococcus xanthus (myxobacterales). i. production, physico-chemical and biological properties, and mechanism of action. | from the cell mass and culture supernatant of myxococcus xanthus strain mx x12 an antibiotic activity against yeasts, molds and some gram-positive bacteria could be extracted. it consisted of 4 biologically active compounds which were named myxalamid a, b, c and d. the main component, myxalamid b, was shown to block in beef heart submitochondrial particles the respiratory chain at the site of complex i, i.e. nadh: ubiquinone oxidoreductase. the myxalamids are new antibiotics. | 1983 | 6415031 |
| pigments with antibiotic activity from myxococcus coralloides. | a strain of myxococcus coralloides produces pigments with antibiotic activity. the pigments are non-diffusible and become detectable at the beginning of the autolytic phase. red pigments produced by vegetatively growing cells were extracted by acetone treatment. the crude extract when chromatographed yielded several fractions, two of which were active against certain gram-positive bacteria. both fractions were partial purified in thin layer chromatography and can be differentiated according to c ... | 1983 | 6415367 |
| protein and lipid methylation by methionine and s-adenosylmethionine in myxococcus xanthus. | methylation of lipids and proteins has been examined in myxococcus xanthus using radioactive methionine and s-adenosylmethionine as methyl donors. s-adenosylmethionine is shown to be taken up by these cells and utilized directly. this permits detection of methylation in the presence of protein synthesis. patterns of methylation obtained using methionine and s-adenosylmethionine during vegetative growth are compared by polyacrylamide gel electrophoresis, and inhibitors of protein synthesis and s- ... | 1983 | 6418366 |
| amino acid precursors of myxococcus xanthus antibiotic ta. | the production of myxococcus xanthus antibiotic ta was stimulated by addition of alanine, serine and glycine to casitone medium. these three amino acids served as the major biosynthetic precursors of the antibiotic. alanine and serine were incorporated via acetate. in casitone medium supplemented with alanine and serine, 29 to 30 of the 34 carbon atoms of antibiotic ta were derived from these two amino acids. both carbon atoms of glycine were incorporated into antibiotic ta by a mechanism not in ... | 1983 | 6418704 |
| the myxopyronins, new inhibitors of bacterial rna synthesis from myxococcus fulvus (myxobacterales). | from the culture supernatant of the myxobacterium, myxococcus fulvus strain mx f50, an antibiotic activity was isolated which blocked growth of many gram-positive and several gram-negative bacteria, but not of yeasts and fungi. the activity consisted of two closely related compounds, myxopyronins a and b. the myxopyronins appear to be new antibiotics, and seem to specifically inhibit bacterial rna polymerase. | 1983 | 6420386 |
| a macrocyclic antibiotic m-230b produced by myxococcus xanthus. isolation and characterization. | myxococcus xanthus strain m516e produced at least three related antibiotics against gram-positive and gram-negative bacteria. from physico-chemical properties, a main component was identical to myxovirescin a and a second component, designated m-230b was found to be an antibiotic which is closely related to myxovirescin a. the structure of m-230b was determined from its physico-chemical properties, especially from 13c nmr spectrum as compared with that of myxovirescin a. the addition of alcohol, ... | 1984 | 6421789 |
| identification of a development-specific promoter of myxococcus xanthus. | in the chromosome of myxococcus xanthus, two homologous genes for protein s, a development-specific protein, are tandemly repeated with a 1.4 x 10(3) base-pair sequence between the two genes. two synthetic oligodeoxyribonucleotides were used as specific probes for individual transcripts from the upstream gene 1 and the downstream gene 2, respectively. the gene 2 transcript was detected only during developmental growth, while the gene 1 transcript was not detected during developmental or vegetati ... | 1984 | 6425506 |
| autoplaquing in myxococcus strains. | autoplaquing has been observed in myxococcus strains freshly isolated from soil. initial observations suggest that this phenomenon is not induced by elevated temperature or visible light; we suggest that it may be the result of a derangement in the developmental autolytic mechanism within the cell. | 1984 | 6427190 |
| verification of protein sequence by fast atom bombardment mass spectrometry. amino acid sequence of protein s, a development-specific protein of myxococcus xanthus. | a mass spectrometric method was applied to protein s, a development-specific protein of myxococcus xanthus, in order to verify the amino acid sequence deduced from the nucleotide sequence of its gene. on examining proteolytic digests of the protein by fast atom bombardment mass spectrometry without separation of individual peptides, signals corresponding to individual peptides were observed in the mass spectra. the mass values of the observed signals were correlated to the theoretical mass value ... | 1984 | 6427208 |
| the myxovalargins, new peptide antibiotics from myxococcus fulvus (myxobacterales). i. cultivation, isolation, and some chemical and biological properties. | antibiotic activity was isolated from the culture supernatant of the myxobacterium myxococcus fulvus strain mx f65. it was active against gram-positive bacteria (mic 0.3 approximately 5 micrograms/ml), at higher concentrations also against gram-negative ones (mic 6 approximately 100 micrograms/ml), and not at all against yeasts and molds. the activity could be resolved into 4 closely related peptides, the myxovalargins. one of them, myxovalargin a, was by far the most plentiful. the compounds ap ... | 1983 | 6432761 |
| production and properties of a bacteriocin from myxococcus coralloides d. | myxococcus coralloides d was found to produce a substance with a narrow range of antibacterial activity. this substance was produced during the exponential growth phase and was not inducible by ultraviolet light or mitomycin c treatment. the bacteriocin was precipitable by ammonium sulphate, and showed resistance to heat (100 degrees c for 10 min), trypsin, lysozyme, beta-glucuronidase, dnase, rnase, acetone, ethyl ether, urea and mercaptoethanol; it was partially destroyed by pronase and inacti ... | 1984 | 6436223 |
| abnormal motility and fruiting behavior of myxococcus xanthus bacteriophage-resistant strains induced by a clear-plaque mutant of bacteriophage mx8. | myxococcus xanthus mutants resistant to a clear-plaque derivative of phage mx8 were isolated. a significant fraction of the mutants, easily recognizable by their colony morphology, were induced by the presence of the phage and may correspond to low-frequency lysogens. they were all defective in cell motility and showed the same nonfruiting phenotype under starvation conditions. | 1984 | 6438060 |
| autocides produced by myxococcus xanthus. | ethanol extracts of myxococcus xanthus contained several substances, referred to as autocides, which were bactericidal to the producing strain but showed no activity against other bacteria. the autocides were produced by growing cells and remained largely cell bound throughout the growth cycle; ca. 5% of the autocidal activity was found in the supernatant fluid at the time cell lysis began. the autocides were separated by sequential-column and thin-layer chromatography into five active fractions ... | 1984 | 6438061 |
| [immunomodulating activity of the genus myxococcus]. | 1984 | 6443018 | |
| changes in cell surface hydrophobicity of myxococcus xanthus are correlated with sporulation-related events in the developmental program. | cell surface hydrophobicity was measured in the bacterium myxococcus xanthus during vegetative growth, fruiting body formation, and glycerol-induced spore formation by the method of rosenberg et al. (fems microbiol. lett. 9:29-33, 1980). a significant decrease in cell surface hydrophobicity was observed 12 to 36 h after fruiting body formation and 60 to 120 min after glycerol-induced sporulation. the hydrophilic shift was correlated with the ability of the cells to sporulate but not with their a ... | 1984 | 6746578 |
| accumulation of guanosine tetraphosphate and guanosine pentaphosphate in myxococcus xanthus during starvation and myxospore formation. | cultures of myxococcus xanthus develop multicellular fruiting bodies when starved for carbon and nitrogen sources on an agar surface. under these conditions of severe starvation, cultures rapidly accumulated a compound identified as guanosine tetraphosphate by chromatographic migration of the compound and of its major acid and alkali breakdown products. the accumulation of guanosine tetraphosphate was reduced in the presence of tetracycline, indicating that it may be synthesized by mechanisms si ... | 1980 | 6766441 |
| guanosine pentaphosphate and guanosine tetraphosphate accumulation and induction of myxococcus xanthus fruiting body development. | development of multicellular fruiting bodies of myxococcus xanthus can be induced by limitation of any of a number of different classes of amino acids. investigated were amino acids that wild-type strains of m. xanthus are unable to synthesize (isoleucine, leucine, and valine), can synthesize at a low rate (phenylalanine), or can normally synthesize at an adequate rate (tryptophan and serine). in general, gradual rather than abrupt starvation for an essential amino acid was required for the indu ... | 1980 | 6766442 |
| separation and properties of the cytoplasmic and outer membranes of vegetative cells of myxococcus xanthus. | we have developed methods for separating the cytoplasmic and outer membranes of vegetative cells of myxococcus xanthus. the total membrane fraction from ethylenediaminetetraacetic acid-lysozyme-treated cells was resolved into three major fractions by isopycnic density centrifugation. between 85 and 90% of the succinate dehydrogenase and cyanide-sensitive reduced nicotinamide adenine dinucleotide oxidase activity was found in the first (i) fraction (rho = 1.221 g/ml) and 80% of the membrane-assoc ... | 1980 | 6767694 |
| preliminary crystallographic data for protein s, a development-specific protein of myxococcus xanthus. | protein s, which is produced only during the developmental cycle of myxococcus xanthus, has been crystallized using 2-methyl-2,4-pentanediol as a precipitating agent. the crystals were very stable in the x-ray beam for up to 150 h and diffracted to a resolution of 2.2 a. the crystals belong to the orthorhombic space group p212121 with unit cell dimensions a = 52.99 a, b = 60.10 a, and c = 102.16 a. each asymmetric unit consists of two monomers of protein s, each having a molecular weight of 23,0 ... | 1980 | 6767725 |
| adenylate energy charge during fruiting body formation by myxococcus xanthus. | the adenylate energy charge of developing myxococcus xanthus cells was measured. the energy charge of vegetative cells (0.81) does not change significantly during the course of fruiting body formation. furthermore, myxospores, which are resistant, resting cells present in the fruiting body, have a relatively high energy charge (0.73). | 1980 | 6769905 |
| s-adenosylmethionine biosynthesis in myxococcus xanthus. | 1980 | 6773804 | |
| the primary structure of fulvocin c from myxococcus fulvus. | the primary structure of fulvocin c, a bacteriocin produced by myxococcus fulvus strain mx f16, has been determined. this new bactericidal protein is composed of 45 amino acid residues and has a molecular weight of 4672. it contains no lipids or carbohydrates, indicating that only the protein molecule is responsible for its biological activity. | 1981 | 6783114 |
| excreted adenosine is a cell density signal for the initiation of fruiting body formation in myxococcus xanthus. | 1981 | 6788625 | |
| myxothiazol, an antibiotic from myxococcus fulvus (myxobacterales). i. cultivation, isolation, physico-chemical and biological properties. | myxothiazol (ab-mx f16-1), a new antifungal antibiotic, is produced by the myxobacterium myxococcus fulvus strain mx f16. it is active against many filamentous fungi, and completely inhibits growth of mucor hiemalis at a concentration of 2 micrograms/ml. the molecular formula of myxothiazol was determined to e c25h33n3o3s2. | 1980 | 6788741 |
| plasmid-mediated uv-protection in myxococcus xanthus. | plasmid r46 was successfully transferred from escherichia coli k=12 into myxococcus xanthus strain md-1 but not into m. xanthus strain xk. plasmid r68.45 was transferred from e. coli k-12 into both strains of m. xanthus. the effects of these plasmids on survival of m. xanthus after ultraviolet (uv)-244 nm irradiation, the ability of m. xanthus to reactivate irradiated myxophages, and weigle reactivation of uv-irradiated effect on uv survival of m. xanthus, but increased the host's ability to rea ... | 1981 | 6790909 |
| misrepair mutagenesis in myxococcus xanthus: induction of rifampicin-resistant mutants by n-methyl-n'-nitro-n-nitrosoguanidine and ultraviolet-irradiation. | in the ultraviolet (uv)-mutable bacterium, myxococcus xanthus, dose response curves for the induction of rifampicin-resistant (rifr) mutants were compared with dose response curves for weigle(w)-reactivation of the uv-irradiated phage mx4 at a phage survival of 5 x 10(-6). in most strains examined, including a uvr mutant, these curves are largely similar. unexpectedly the uv-sensitive strain m. xanthus bt, which is unable to perform w-reactivation, is nevertheless uv-mutable. this result may ind ... | 1981 | 6793809 |
| development-specific protein s of myxococcus xanthus: purification and characterization. | protein s, a development-specific protein of myxococcus xanthus, was purified from the cells of a late stage of development and crystallized. its circular dichroism spectra indicated that protein s had a high content of beta-structure in both the presence and absence of calcium ion, which is required for self-assembly of protein s on the myxospore surface. its amino and carboxyl terminal sequences were determined to be alanine-aspartic acid-isoleucine-glycine-valine-alanine-methionine-asparagine ... | 1981 | 6795183 |
| purification and characterization of myxobacterial hemagglutinin, a development-specific lectin of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium that has a complex life cycle which includes cellular aggregation and sporulation. during the period of cellular aggregation, a lectin-like protein called myxobacterial hemagglutinin (mbha) is synthesized. a four-step purification procedure for mbha is described. it consists of chromatography on deae-cellulose, cm-cellulose, and hydroxyapatite, followed by gel filtration on bio-gel p-30. this procedure gives good yields of mbha (40-50%) free of con ... | 1981 | 6795208 |
| localization of myxobacterial hemagglutinin in the periplasmic space and on the cell surface of myxococcus xanthus during developmental aggregation. | during the period of developmental aggregation which precedes fruiting body formation, the bacterium myxococcus xanthus produces a large amount of a lectin called myxobacterial hemagglutinin (mbha). sequential cell washing, osmotic shock, and disruption of developmental cells showed that as much as 90% of the total hemagglutinating activity can be recovered in the wash and shock fractions. analysis of the wash and shock fluids by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed t ... | 1981 | 6795209 |
| beta-lactamase activity and resistance to penicillins in myxococcus xanthus. | several mutants and other variants of myxococcus xanthus hp100 were obtained with differences in their sensitivity to carbenicillin and other penicillin derivatives. the specific activities of beta-lactamase in different resistant organisms varied from strain to strain but were consistently higher than in hp100. the relative molecular mass (mr) of the enzyme in m. xanthus hp100 was found to be 22,300. in certain carbenicillin resistant strains a second fraction of beta-lactamase activity of mole ... | 1981 | 6797377 |
| synthesis of several membrane proteins during developmental aggregation in myxococcus xanthus. | we have examined the pattern of synthesis of several membrane proteins during the aggregation phase of development in myxococcus xanthus. development was initiated by plating vegetative cells on polycarbonate filters placed on top of an agar medium that supported fruiting body formation. at various times during aggregation a filter was removed, the cells were pulse-labeled with [35s]methionine, and the membrane proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. ... | 1982 | 6798022 |
| [myxobacteria (myxobacteriales) on leaf surfaces]. | 140 leaf samples were examined, 73 of which (= 52.1%) contained myxobacteria. three species of the genus myxococcus, m. virescens, m. fulvus and m. coralloides, could be found more or less frequently in the phyllosphere of woody plants and annuals. archangium gephyra was observed only once. there was no significant difference in the occurrence of myxobacteria between evergreen leaves and leaves from deciduous trees and shrubs. fruit-trees yielded the best results. | 1981 | 6801873 |
| two-dimensional dna electrophoresis applied to the study of dna methylation and the analysis of genome size in myxococcus xanthus. | 1982 | 6804632 | |
| phosphorylation and methylation of proteins during myxococcus xanthus spore formation. | post-translational modification of proteins was examined during the life cycle of myxococcus xanthus. a specific pattern of protein phosphorylation was observed in vegetative cells. when spore formation was induced by glycerol, significant changes in the pattern of protein phosphorylation were observed, including the phosphorylation of two membrane proteins. in in vitro experiments, the same membrane proteins were phosphorylated by atp when the membrane preparation from cells treated with glycer ... | 1982 | 6806237 |
| fruiting body morphogenesis in submerged cultures of myxococcus xanthus. | induced by starvation, the development of fruiting bodies by myxococcus xanthus on glass and plastic surfaces under a layer of liquid was followed microscopically. calcium ions and a neutral ph were required for development of a myxococcus strain that grew dispersed in liquid culture. initially asymmetric aggregates later became round, and sporulation followed aggregation. | 1982 | 6806248 |
| rna polymerase of myxococcus xanthus: purification and selective transcription in vitro with bacteriophage templates. | dna-dependent rna polymerase from vegetative cells of the gram-negative, fruiting bacterium myxococcus xanthus was purified more than 300-fold by a modified burgess procedure (lowe et al., biochemistry 18:1344-1352, 1979), using polymin p precipitation, 40 to 65% saturated ammonium sulfate fractional precipitation, double-stranded dna cellulose chromatography, a5m gel filtration chromatography, and single-stranded dna agarose chromatography. the last step separated the rna polymerase into a core ... | 1982 | 6806251 |
| induction of coordinated movement of myxococcus xanthus cells. | rhythmically advancing waves of cells, called ripples, arise spontaneously during the aggregation of myxococcus xanthus into fruiting bodies. extracts prepared by washing rippling cells contain a substance that will induce quiescent cells to ripple. three lines of evidence indicate that murein (peptidoglycan) is the ripple-inducing substance in the extracts. first, ripple-inducing activity is associated with the cell envelope of sonically disrupted m. xanthus cells. second, whole cells, cell ext ... | 1982 | 6811560 |
| murein components rescue developmental sporulation of myxococcus xanthus. | murein (peptidoglycan) components are able to rescue sporulation in certain sporulation-defective mutants of myxococcus xanthus. n-acetylglucosamine, n-acetylmuramic acid, diaminopimelic acid, and d-alanine each increase the number of spores produced by spoc mutants. when all four components are included they have a synergistic effect, raising the number of spores produced by spoc mutants to the wild-type level. murein-rescued spores are resistant to heat and sonic oscillation and germinate when ... | 1982 | 6811561 |