| on the distribution of myxobacteria in the temperate south america (author's transl). | 60 soil samples from southern chile, mainly from forests and grassland, yielded six species of myxobacteria. in forest soils myxococcus coralloides and myxococcus fulvus occur frequently, in grassland soils myxococcus coralloides and archangium gephyra are predominating. myxococcus virescens, melittangium lichenicola, and cytobacter fuscus have been observed rarely. it is pointed out that due to climate factors a high soil acidity causes the low nuber of myxobacter species. a comparison with the ... | 1978 | 27046 |
| hemolysin of myxococcus fulvus nk 35 i. production and isolation. | myxococcus fulvus nk 35 has been shown to produce a soluble hemolysin which lysed rabbit, human, horse, and sheep erythrocytes. a medium (varghese's medium) was devised in which a maximum of hemolysin was produced in 6 days at 28 degrees c under static conditions. the lysin was precipitated by complete saturation of the culture filtrate with ammonium sulphate, followed by dialysis against saline. other enzyme systems were destroyed by heating at 100 degrees c. further purification was achieved b ... | 1978 | 104473 |
| purification and effects of fulvocin c, a bacteriocin from myxococcus fulvus mx f16. | fulvocin c is a bacteriocin from myxococcus fulvus mx f16. it has a molecular weight of 4672 and is one of the smallest bacteriocins known. four disulfide bonds give the molecule a tight structure, so that its native form was not attacked by chymotrypsin or pronase. fulvocin c was stable in various organic solvents and could tolerate 80 degrees c in aqueous solution without loss of activity. the killing effect of fulvocin c was observed only at concentrations higher than 0.25 mumol/1. macromolec ... | 1978 | 104692 |
| iso-branched 2- and 3-hydroxy fatty acids as characteristic lipid constituents of some gliding bacteria. | the fatty acids present in the total hydrolysates of several gliding bacteria (myxococcus fulvus, stigmatella aurantiaca, cytophaga johnsonae, cytophaga sp. strain samoa and flexibacter elegans) were analyzed by combined gas-liquid chromatography and mass spectrometry. in addition to 13-methyl-tetradecanoic acid, 15-methyl-hexadecanoic acid, hexadecanoic acid, and hexadecenoic acid, 2- and 3-hydroxy fatty acids comprised up to 50% of the total fatty acids. the majority was odd-numbered and iso-b ... | 1979 | 118159 |
| [aquatic myxobacteria (sporocytophaga cauliformis) and the order "myxobacterales" (author's transl)]. | the indicator function of aquatic myxobacteria for the purpose of evaluating drinking water quality as well as their occurrence in sewage effluent make it desirable to describe these hitherto little known organisms in more detail. to this end, a comparative investigation of anaerobic myxobacteria of the genus sphaerocytophaga, two typical representatives of the order myxobacterales (myxococcus fulvus, sporocytophage cauliformis), and a strain ov vitrepscilla (vitroescilla proteolytica) was under ... | 1979 | 120650 |
| [occurrence and distribution of fruiting body-forming myxobacteria in siebengebirge. comparative studies with special reference to characteristic biotypes]. | in the region of the "siebengebirge" near bonn, six characteristic biotopes were studied with respect to the occurrence of fruiting body forming myxobacteria. 23 different species, belonging to the 8 known genera, were found. the number of species in the respective biotopes varied between 6 and 17, the average numbers of species per sampling area were between 2.1 and 10.0. 15 species were found on dung pellets of wild living herbivorous mammals. deciduous forest soils contained 13 species in spr ... | 1979 | 121178 |
| bacteriocins from myxococcus fulvus (myxobacterales). | bacteriocin-like activities were found in several myxococcus fulvus strains. one strain, mx f16, exerted strong inhibitory effects on several myxobacterial strains. synthesis of its bacteriocinic activity could not be induced by mitomycin. electrophoresis and molecular sieve chromatography revealed at least three different bacteriocinic substances of low molecular weight. | 1977 | 412477 |
| on the utilization in vivo of lycopene and phytoene as precursors for the formation of carotenoid glucoside ester and on the regulation of carotenoid biosynthesis in myxococcus fulvus. | during th logarithmic phase of growth of the myxobacterium myxococcus fulvus the specific carotenoid content and the molar ratio of the two main carotenoids keto-torulene (3',4'-didehydro-beta,psi-caroten-4-one, 15%) and myxobacton ester (1'-glucosyloxy-3',4'-didehydro-1',2'-dihydro-beta,psi-caroten-4-one ester, 80%) are highly constant. when the formation of these carotenoids was prevented by an inhibitory block at the level of phytoene desaturation, the normal specific content is rapidly reach ... | 1975 | 809283 |
| evidence for motility-related fimbriae in the gliding microorganism myxococcus xanthus. | an electron-microscopic examination of negatively stained preparations from cell lysates of myxococcus xanthus and in situ samples of myxococcus xanthus, myxococcus virescens, and myxococcus fulvus has demonstrated the presence of polar fimbriae, about 8.5 nm in diameter, on motile but not nonmotile cells. | 1976 | 824039 |
| nuclear activity and cell division in the microcysts of myxococcus fulvus demonstrated by electron micrography of sections. | electron micrographs of sectioned fruiting bodies confirm that, in myxococcus fulvus, approximately 10% of mature microcysts show appearances interpretable as typical bacterial nuclear activity and cell division. this suggests a simple mechanism for fruiting body development, and its existence bears upon the validity of the classical descriptions of microcyst maturation in myxobacteria. | 1976 | 827459 |
| [investigations on the structure of the sphingolipids of the genus bacteroides (author's transl)]. | in 1972 fritsche and thelen have described the difference between the structure of the komplex lipids of the genus bacteroides and the genus sphaerophorus. further investigations of fritsche demonstrated the possibility of grouping gramnegative anaerobes into the genus bacteroides in spite of the fact, that one of the final products of metabolism of these strains is butyric acid. these strains are the so-called butyric acid producing bacteroides. this paper describes the structure of the still u ... | 1975 | 1202872 |
| the mechanism of action of myxovalargin a, a peptide antibiotic from myxococcus fulvus. | myxovalargin a has two modes of action. at low concentrations (below 1 microgram/ml) it inhibits bacterial protein synthesis specifically and instantaneously. in vitro experiments suggest that it interferes with the binding of aminoacyl trna to the a site of the ribosome. at higher concentrations (above 5 micrograms/ml), or upon prolonged incubation, the antibiotic damages cell membranes. this leads to secondary effects, like decreased o2 consumption or instant break down of rna synthesis, and m ... | 1985 | 2415501 |
| in vitro synthesis of c15-c60 polyprenols in a cell-free system of myxococcus fulvus and determination of chain length by high-performance liquid chromatography. | | 1985 | 3927113 |
| composition of lipopolysaccharides from myxococcus fulvus and other fruiting and non-fruiting myxobacteria. | | 1974 | 4209347 |
| inhibition of carotenoid synthesis in myxococcus fulvus (myxobacterales). | | 1974 | 4211208 |
| effect of spermidine on morphogenesis in myxococcus fulvus. | | 1974 | 4211963 |
| flexibacter elegans and myxococcus fulvus: aerobic gram-negative bacteria containing menaquinones as the only isoprenoid quinones. | | 1974 | 4216336 |
| membranes from myxococcus fulvus (myxobacterales) containing carotenoid glucosides. i. isolation and composition. | | 1972 | 4340261 |
| biosynthesis of carotenoid glucoside esters in myxococcus fulvus (myxobacterales): inhibition by nicotine and carotenoid turnover. | | 1973 | 4713154 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| pyrrolnitrin from myxococcus fulvus (myxobacterales). | | 1982 | 6815147 |
| 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 |
| 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 |
| antifungal activity of myxococcus species 1 production, physicochemical and biological properties of antibiotics from myxococcus fulvus s110 (myxobacterales). | chloroform extracts of the culture supernatant of a strain of myxococcus fulvus isolated from soil were fungistatic and prevented germination of spores of botrytis cinerea. the antibiotics were produced during the exponential phase of growth and the effects of altering medium composition are described. the activity was fractionated into neutral, acidic and basic fractions. the neutral fraction had a molecular weight of 244 and was tentatively identified as 11-phenyl-undecadiene-2-ol. the acidic ... | 1993 | 8469176 |
| a method for the selective isolation of myxococcus directly from soil. | a new method is described for the selective isolation of species of myxococcus directly from soil by dilution plating. the method involves suppression of competing microorganisms with antibiotics combined with air drying and wet heat treatment of soils. fungi were eliminated by supplementing the plating medium with cycloheximide and nystatin. non-sporulating bacteria were controlled by air drying soils and then heating aqueous soil dilutions for 10 min at 56 degrees c. the predominant sporulatin ... | 1996 | 8652116 |
| further characterization and in situ localization of chain-like aggregates of the gliding bacteria myxococcus fulvus and myxococcus xanthus. | for the first time, chain-like aggregates, called "strands," have been enriched from crude cell wall preparations of liquid-grown vegetative cells of two strains of myxococcus xanthus. these strands are highly isomorphic to macromolecular structures, previously described for myxococcus fulvus (lünsdorf and reichenbach, j. gen. microbiol. 135:1633-1641, 1989). the strands are morphologically composed of ring elements, consisting of six or more peripheral protein masses and possibly three small ce ... | 1997 | 9023208 |
| a chaperone in the hsp70 family controls production of extracellular fibrils in myxococcus xanthus. | three independent tn5-lac insertions in the s1 locus of myxococcus xanthus inactivate the sglk gene, which is nonessential for growth but required for social motility and multicellular development. the sequence of sglk reveals that it encodes a homologue of the chaperone hsp70 (dnak). the sglk gene is cotranscribed with the upstream grps gene, which encodes a grpe homologue. unlike sglk, grps is not required for social motility or development. wild-type m. xanthus is encased in extracellular pol ... | 1998 | 9765567 |
| purification, characterization, and cloning of a eubacterial 3-hydroxy-3-methylglutaryl coenzyme a reductase, a key enzyme involved in biosynthesis of terpenoids. | the eubacterial 3-hydroxy-3-methylglutaryl coenzyme a (hmg-coa) reductase (ec 1.1.1.34) was purified 3,000-fold from streptomyces sp. strain cl190 to apparent homogeneity with an overall yield of 2.1%. the purification procedure consisted of (nh4)2so4 precipitation, heat treatment and anion exchange, hydrophobic interaction, and affinity chromatographies. the molecular mass of the enzyme was estimated to be 41 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 100 to 105 kda by ... | 1999 | 9973353 |
| kr025, a new cytotoxic compound from myxococcus fulvus. | a new bithiazole, kr-025 (1), was isolated from myxococcus fulvus. its structure was elucidated by spectroscopic analysis. in addition to 1, the strain produced relatively large quantities of a second, closely related antibiotic, myxothiazol. these compounds demonstrated potent cytotoxicity against human tumor cells. | 1999 | 10096868 |
| gliding motility in bacteria: insights from studies of myxococcus xanthus. | gliding motility is observed in a large variety of phylogenetically unrelated bacteria. gliding provides a means for microbes to travel in environments with a low water content, such as might be found in biofilms, microbial mats, and soil. gliding is defined as the movement of a cell on a surface in the direction of the long axis of the cell. because this definition is operational and not mechanistic, the underlying molecular motor(s) may be quite different in diverse microbes. in fact, studies ... | 1999 | 10477310 |
| conservation of the pyrrolnitrin biosynthetic gene cluster among six pyrrolnitrin-producing strains. | the prnabcd gene cluster from pseudomonas fluorescens encodes the biosynthetic pathway for pyrrolnitrin, a secondary metabolite derived from tryptophan which has strong anti-fungal activity. we used the prn genes from p. fluorescens strain bl915 as a probe to clone and sequence homologous genes from three other pseudomonas strains, burkholderia cepacia and myxococcus fulvus. with the exception of the prna gene from m. fulvus59% similar among the strains, indicating that the biochemical pathway f ... | 1999 | 10547442 |
| a gene cluster for the mevalonate pathway from streptomyces sp. strain cl190. | a biosynthetic 3-hydroxy-3-methylglutaryl coenzyme a reductase (ec 1. 1.1.34), the rate-limiting enzyme of the mevalonate pathway for isopentenyl diphosphate biosynthesis, had previously been purified from streptomyces sp. strain cl190 and its corresponding gene (hmgr) had been cloned (s. takahashi, t. kuzuyama, and h. seto, j. bacteriol. 181:1256-1263, 1999). sequence analysis of the flanking regions of the hmgr gene revealed five new open reading frames, orfa to -e, which showed similarity to ... | 2000 | 10894721 |
| identification, evolution, and essentiality of the mevalonate pathway for isopentenyl diphosphate biosynthesis in gram-positive cocci. | the mevalonate pathway and the glyceraldehyde 3-phosphate (gap)-pyruvate pathway are alternative routes for the biosynthesis of the central isoprenoid precursor, isopentenyl diphosphate. genomic analysis revealed that the staphylococci, streptococci, and enterococci possess genes predicted to encode all of the enzymes of the mevalonate pathway and not the gap-pyruvate pathway, unlike bacillus subtilis and most gram-negative bacteria studied, which possess only components of the latter pathway. p ... | 2000 | 10894743 |
| the nuclear cycle of myxococcus fulvus. | | 1957 | 13406220 |
| fruiting body populations of myxococcus fulvus (myxobacterales). | | 1965 | 14324921 |
| cloning, sequencing, and functional analysis of an iterative type i polyketide synthase gene cluster for biosynthesis of the antitumor chlorinated polyenone neocarzilin in "streptomyces carzinostaticus". | neocarzilins (nczs) are antitumor chlorinated polyenones produced by "streptomyces carzinostaticus" var. f-41. the gene cluster responsible for the biosynthesis of nczs was cloned and characterized. dna sequence analysis of a 33-kb region revealed a cluster of 14 open reading frames (orfs), three of which (orf4, orf5, and orf6) encode type i polyketide synthase (pks), which consists of four modules. unusual features of the modular organization is the lack of an obvious acyltransferase domain on ... | 2004 | 15328113 |
| three prochlorococcus cyanophage genomes: signature features and ecological interpretations. | the oceanic cyanobacteria prochlorococcus are globally important, ecologically diverse primary producers. it is thought that their viruses (phages) mediate population sizes and affect the evolutionary trajectories of their hosts. here we present an analysis of genomes from three prochlorococcus phages: a podovirus and two myoviruses. the morphology, overall genome features, and gene content of these phages suggest that they are quite similar to t7-like (p-ssp7) and t4-like (p-ssm2 and p-ssm4) ph ... | 2005 | 15828858 |
| characteristics and living patterns of marine myxobacterial isolates. | the growth, morphology, and life cycle of two marine myxobacterial isolates, halotolerant myxococcus fulvus strain hw-1 and halophilic haliangium ochraceum strain smp-2, were studied as models to determine the living patterns of myxobacteria in the ocean. the growth, morphology, and development of halotolerant strain hw-1 shifted in response to salinity. the optimal seawater concentration for growth of hw-1 was 0 to 80% (salinity, 0.1 to 2.9%), and the strain grew poorly in media with a salinity ... | 2005 | 15933036 |
| preliminary crystallographic characterization of prnb, the second enzyme in the pyrrolnitrin biosynthetic pathway. | pyrrolnitrin is the active ingredient of drugs for the treatment of superficial fungal infections and was used as a lead structure for the development of fludioxonil. it is an effective agent for plant diseases caused by the fungal pathogen rhizoctonia solani. pyrrolnitrin is made in four steps, the second of which, catalyzed by prnb, is a novel chemical rearrangement of 7-chlorotryptophan. prnb was overproduced in pseudomonas fluorescens (bl915) and well diffracting crystals were obtained of a ... | 2006 | 17077497 |
| bithiazole metabolites from the myxobacterium myxococcus fulvus. | two new bithiazole metabolites (3, 4) along with the previously reported compounds (1, 2) were isolated from the culture broth of the gliding bacterium myxococcus fulvus collected from a korean soil. the structures of these compounds were determined to be analogous to myxothiazole a on the basis of combined spectroscopic analyses. the new compounds exhibited significant cytotoxicity and moderate antifungal activity against the mouse fibloblast cell-line l929 and candida albicans, respectively. t ... | 2007 | 17329897 |
| new locus important for myxococcus social motility and development. | the mts locus in salt-tolerant myxococcus fulvus hw-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation. the homologous genes in myxococcus xanthus are also important for social motility and fruiting-body development. the mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species. | 2007 | 17720782 |
| spatial organization of myxococcus xanthus during fruiting body formation. | microcinematography was used to examine fruiting body development of myxococcus xanthus. wild-type cells progress through three distinct phases: a quiescent phase with some motility but little aggregation (0 to 8 h), a period of vigorous motility leading to raised fruiting bodies (8 to 16 h), and a period of maturation during which sporulation is initiated (16 to 48 h). fruiting bodies are extended vertically in a series of tiers, each involving the addition of a cell monolayer on top of the upp ... | 2007 | 17921303 |
| the second enzyme in pyrrolnitrin biosynthetic pathway is related to the heme-dependent dioxygenase superfamily. | pyrrolnitrin is a commonly used and clinically effective treatment for fungal infections and provides the structural basis for the more widely used fludioxinil. the pyrrolnitrin biosynthetic pathway consists of four chemical steps, the second of which is the rearrangement of 7-chloro-tryptophan by the enzyme prnb, a reaction that is so far unprecedented in biochemistry. when expressed in pseudomonas fluorescens, prnb is red in color due to the fact that it contains 1 mol of heme b per mole of pr ... | 2007 | 17924666 |
| genome evolution and the emergence of fruiting body development in myxococcus xanthus. | lateral gene transfer (lgt) is thought to promote speciation in bacteria, though well-defined examples have not been put forward. | 2007 | 18159227 |
| discovery of the autonomously replicating plasmid pmf1 from myxococcus fulvus and development of a gene cloning system in myxococcus xanthus. | myxobacteria are very important due to their unique characteristics, such as multicellular social behavior and the production of diverse and novel bioactive secondary metabolites. however, the lack of autonomously replicating plasmids has hindered genetic manipulation of myxobacteria for decades. to determine whether indigenous plasmids are present, we screened about 150 myxobacterial strains, and a circular plasmid designated pmf1 was isolated from myxococcus fulvus 124b02. sequence analysis sh ... | 2008 | 18245244 |
| 16s rrna gene and 16s-23s rrna gene internal transcribed spacer sequences analysis of the genus myxococcus. | phylogenetic relationships of the species belonging to the genus myxococcus were elucidated based on the sequences of 16s rrna genes and 16s-23s rrna gene internal transcribed spacer (its) regions. the myxococcus species were consequently classified into four distinct groups. the type strain of myxococcus coralloides occupied an independent position (group 1); it has been recently reclassified as corallococcus coralloides. group 2 comprised the type strains of both myxococcus virescens and myxoc ... | 2008 | 18355284 |
| transcription inactivation through local refolding of the rna polymerase structure. | structural studies of antibiotics not only provide a shortcut to medicine allowing for rational structure-based drug design, but may also capture snapshots of dynamic intermediates that become 'frozen' after inhibitor binding. myxopyronin inhibits bacterial rna polymerase (rnap) by an unknown mechanism. here we report the structure of dmyx--a desmethyl derivative of myxopyronin b--complexed with a thermus thermophilus rnap holoenzyme. the antibiotic binds to a pocket deep inside the rnap clamp h ... | 2009 | 18946472 |
| transcription inactivation through local refolding of the rna polymerase structure. | structural studies of antibiotics not only provide a shortcut to medicine allowing for rational structure-based drug design, but may also capture snapshots of dynamic intermediates that become 'frozen' after inhibitor binding. myxopyronin inhibits bacterial rna polymerase (rnap) by an unknown mechanism. here we report the structure of dmyx--a desmethyl derivative of myxopyronin b--complexed with a thermus thermophilus rnap holoenzyme. the antibiotic binds to a pocket deep inside the rnap clamp h ... | 2009 | 18946472 |
| the rna polymerase "switch region" is a target for inhibitors. | the alpha-pyrone antibiotic myxopyronin (myx) inhibits bacterial rna polymerase (rnap). here, through a combination of genetic, biochemical, and structural approaches, we show that myx interacts with the rnap "switch region"--the hinge that mediates opening and closing of the rnap active center cleft--to prevent interaction of rnap with promoter dna. we define the contacts between myx and rnap and the effects of myx on rnap conformation and propose that myx functions by interfering with opening ... | 2008 | 18957204 |
| seawater-regulated genes for two-component systems and outer membrane proteins in myxococcus. | when salt-tolerant myxococcus cells are moved to a seawater environment, they change their growth, morphology, and developmental behavior. outer membrane proteins and signal transduction pathways may play important roles in this shift. chip hybridization targeting the genes predicted to encode 226 two-component signal transduction pathways and 74 outer membrane proteins of m. xanthus dk1622 revealed that the expression of 55 corresponding genes in the salt-tolerant strain m. fulvus hw-1 was sign ... | 2009 | 19151139 |
| acetylcholinesterase-inhibiting activity of pyrrole derivatives from a novel marine gliding bacterium, rapidithrix thailandica. | acetylcholinesterase-inhibiting activity of marinoquinoline a (1), a new pyrroloquinoline from a novel species of a marine gliding bacterium rapidithrix thailandica, was assessed (ic(50) 4.9 microm). two related pyrrole derivatives, 3-(2'-aminophenyl)-pyrrole (3) and 2,2-dimethyl-pyrrolo-1,2-dihydroquinoline (4), were also isolated from two other strains of r. thailandica. the isolation of 3 from a natural source is reported here for the first time. compound 4 was proposed to be an isolation art ... | 2008 | 19172195 |
| combining inhibitor resistance-conferring mutations in cytochrome b creates conditional synthetic lethality in saccharomyces cerevisiae. | the mitochondrial cytochrome bc(1) complex is an essential respiratory enzyme in oxygen-utilizing eukaryotic cells. its core subunit, cytochrome b, contains two sites, center p and center n, that participate in the electron transfer activity of the bc(1) complex and that can be blocked by specific inhibitors. in yeast, there are various point mutations that confer inhibitor resistance at center p or center n. however, there are no yeast strains in which the bc(1) complex is resistant to both cen ... | 2009 | 19179332 |
| deciphering the hunting strategy of a bacterial wolfpack. | myxococcus xanthus is a common soil bacterium with an intricate multicellular lifestyle that continues to challenge the way in which we conceptualize the capabilities of prokaryotic organisms. myxococcus xanthus is the preferred laboratory representative from the myxobacteria, a family of organisms distinguished by their ability to form highly structured biofilms that include tentacle-like packs of surface-gliding cell groups, synchronized rippling waves of oscillating cells and massive spore-fi ... | 2009 | 19519767 |
| improving cellular properties for genetic manipulation by dispersed growing mutagenesis in myxococcus fulvus hw-1. | one of the key limitations to genetic manipulation in myxobacteria is that the cells grow in clumps in liquid. a salt-tolerant strain hw-1 of myxococcus fulvus was treated with uv irradiation and produced a completely dispersedly growing mutant uv684. there were no significant differences between the parent hw-1 and the mutant uv684 in terms of salt-tolerant growth. the mutant uv684 and the parent strain had the similar abilities of the fruiting body formation and s motility. interestingly, the ... | 2010 | 19998037 |
| hdsp, a horizontally transferred gene required for social behavior and halotolerance in salt-tolerant myxococcus fulvus hw-1. | myxococcus fulvus hw-1, a salt-tolerant bacterial strain, which was isolated from a coastal environment, changes its behavior with different salinities. to study the relationship between behavioral shifts and the adaption to oceanic conditions, the hw-1 strain was randomly mutagenized using transposon insertion, producing a dispersed-growing mutant, designated ylh0401. the mutant did not develop fruiting bodies and myxospores, was deficient in s-motility, produced less extracellular matrix and w ... | 2010 | 20410933 |
| the ternary complex of prnb (the second enzyme in the pyrrolnitrin biosynthesis pathway), tryptophan, and cyanide yields new mechanistic insights into the indolamine dioxygenase superfamily. | pyrrolnitrin (3-chloro-4-(2'-nitro-3'-chlorophenyl)pyrrole) is a broad-spectrum antifungal compound isolated from pseudomonas pyrrocinia. four enzymes (prna, prnb, prnc, and prnd) are required for pyrrolnitrin biosynthesis from tryptophan. prnb rearranges the indole ring of 7-cl-l-tryptophan and eliminates the carboxylate group. prnb shows robust activity in vivo, but in vitro activity for prnb under defined conditions remains undetected. the structure of prnb establishes that the enzyme belongs ... | 2010 | 20421301 |
| nitroaromatic compounds, from synthesis to biodegradation. | nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. this important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. unfortunately, their extensive use has led to environmental contamination of soil and groundwater. the nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalc ... | 2010 | 20508249 |
| preparation, purification and characteristics of an aflatoxin degradation enzyme from myxococcus fulvus ansm068. | to prepare, purify and characterize an extracellular enzyme from myxococcus fulvus ansm068, designated as myxobacteria aflatoxin degradation enzyme (made), which possesses degradation activity against aflatoxin b(1) (afb(1) ), g(1) (afg(1) ) and m(1) (afm(1) ) in solution. | 2010 | 21040271 |
| in vitro efficacy of myxococcus fulvus ansm068 to biotransform aflatoxin b(1). | aflatoxin b(1) (afb(1)) is commonly found in cereals and animal feeds and causes a significant threat to the food industry and animal production. several microbial isolates with high afb(1) transformation ability have been identified in our previous studies. the aim of this research was to characterize one of those isolates, myxococcus fulvus ansm068, and to explore its biotransformation mechanism. the bacterial isolate of m. fulvus ansm068, isolated from deer feces, was able to transform afb(1) ... | 2010 | 21152320 |
| fatty acid-related phylogeny of myxobacteria as an approach to discover polyunsaturated omega-3/6 fatty acids. | in an analysis of 47 aerobic myxobacterial strains, representing 19 genera in suborders cystobacterineae, nannocystineae, sorangiineae, and a novel isolate, "aetherobacter" sbsr008, an enormously diverse array of fatty acids (fas) was found. the distribution of straight-chain fatty acids (scfas) and branched-chain fatty acids (bcfas) supports the reported clustering of strains in the phylogenetic tree based on 16s rrna genes. this finding additionally allows the prediction and assignment of the ... | 2011 | 21317327 |
| natural transformation of myxococcus xanthus. | myxococcus xanthus belongs to the delta class of the proteobacteria and is notable for its complex life-style with social behaviors and relatively large genome. although previous observations have suggested the existence of horizontal gene transfer in m. xanthus, its ability to take up exogenous dna via natural transformation has not been experimentally demonstrated. in this study, we achieved natural transformation in m. xanthus using the autonomously replicating myxobacterial plasmid pzjy41 as ... | 2011 | 21378184 |
| characterization of the partitioning system of myxococcus plasmid pmf1. | pmf1 is the only autonomously replicating plasmid that has been recently identified in myxobacteria. this study characterized the partitioning (par) system of this plasmid. the fragment that significantly increased the retaining stability of plasmids in myxococcus cells in the absence of selective antibiotics contained three open reading frames (orfs) pmf1.21-pmf1.23 (parcab). the pmf1.22 orf (para) is homologous to members of the para atpase family, with the highest similarity (56%) to the sphi ... | 2011 | 22174771 |
| Biogeography and phylogenetic diversity of a cluster of exclusively marine myxobacteria. | Myxobacteria are common in terrestrial habitats and well known for their formation of fruiting bodies and production of secondary metabolites. We studied a cluster of myxobacteria consisting only of sequences of marine origin (marine myxobacteria cluster, MMC) in sediments of the North Sea. Using a specific PCR, MMC sequences were detected in North Sea sediments down to 2.2?m depth, but not in the limnetic section of the Weser estuary and other freshwater habitats. In the water column, this clus ... | 2011 | 22189493 |
| Biogeography and phylogenetic diversity of a cluster of exclusively marine myxobacteria. | Myxobacteria are common in terrestrial habitats and well known for their formation of fruiting bodies and production of secondary metabolites. We studied a cluster of myxobacteria consisting only of sequences of marine origin (marine myxobacteria cluster, MMC) in sediments of the North Sea. Using a specific PCR, MMC sequences were detected in North Sea sediments down to 2.2?m depth, but not in the limnetic section of the Weser estuary and other freshwater habitats. In the water column, this clus ... | 2011 | 22189493 |
| genome sequence of the halotolerant marine bacterium myxococcus fulvus hw-1. | myxococcus fulvus hw-1 (atcc baa-855) is a halotolerant marine myxobacterium. this strain exhibits complex social behaviors in the presence of low concentrations of seawater but adopts an asocial living pattern under oceanic conditions. the whole genome of m. fulvus hw-1 will enable us to further investigate the details of its evolution. | 2011 | 21868801 |
| identification of novel imidazo[1,2-a]pyridine inhibitors targeting m. tuberculosis qcrb. | mycobacterium tuberculosis is a major human pathogen and the causative agent for the pulmonary disease, tuberculosis (tb). current treatment programs to combat tb are under threat due to the emergence of multi-drug and extensively-drug resistant tb. through the use of high throughput whole cell screening of an extensive compound library a number of imidazo[1,2-a]pyridine (ip) compounds were obtained as potent lead molecules active against m. tuberculosis and mycobacterium bovis bcg. the ip inhib ... | 2012 | 23300833 |
| chemosensory regulation of a heat-repeat protein couples aggregation and sporulation in myxococcus xanthus. | chemosensory systems are complex, highly modified two-component systems (tcs) used by bacteria to control various biological functions ranging from motility to sporulation. chemosensory systems and tcs both modulate phosphorelays comprised of histidine kinases and response regulators, some of which are single-domain response regulators (sd-rrs) such as chey. in this study, we have identified and characterized the che7 chemosensory system of myxococcus xanthus, a common soil bacterium which displ ... | 2014 | 24957622 |
| planctomycetes as novel source of bioactive molecules. | marine environments are a fruitful source of bioactive compounds some of which are the newest leading drugs in medicinal therapeutics. of particular importance are organisms like sponges and macroalgae and their associated microbiome. planctomycetes, abundant in macroalgae biofilms, are promising producers of bioactive compounds since they share characteristics, like large genomes and complex life cycles, with the most bioactive bacteria, the actinobacteria. furthermore, genome mining revealed t ... | 2016 | 27570520 |
| related giant viruses in distant locations and different habitats: acanthamoeba polyphaga moumouvirus represents a third lineage of the mimiviridae that is close to the megavirus lineage. | the 1,021,348 base pair genome sequence of the acanthamoeba polyphaga moumouvirus, a new member of the mimiviridae family infecting acanthamoeba polyphaga, is reported. the moumouvirus represents a third lineage beside mimivirus and megavirus. thereby, it is a new member of the recently proposed megavirales order. this giant virus was isolated from a cooling tower water in southeastern france but is most closely related to megavirus chiliensis, which was isolated from ocean water off the coast o ... | 2012 | 23221609 |
| gene-family extension measures and correlations. | the existence of multiple copies of genes is a well-known phenomenon. a gene family is a set of sufficiently similar genes, formed by gene duplication. in earlier works conducted on a limited number of completely sequenced and annotated genomes it was found that size of gene family and size of genome are positively correlated. additionally, it was found that several atypical microbes deviated from the observed general trend. in this study, we reexamined these associations on a larger dataset con ... | 2016 | 27527218 |
| isoprenoid biosynthesis: the evolution of two ancient and distinct pathways across genomes. | isopentenyl diphosphate (ipp) is the central intermediate in the biosynthesis of isoprenoids, the most ancient and diverse class of natural products. two distinct routes of ipp biosynthesis occur in nature: the mevalonate pathway and the recently discovered deoxyxylulose 5-phosphate (dxp) pathway. the evolutionary history of the enzymes involved in both routes and the phylogenetic distribution of their genes across genomes suggest that the mevalonate pathway is germane to archaebacteria, that th ... | 2000 | 11078528 |
| a persistent and diverse airway microbiota present during chronic obstructive pulmonary disease exacerbations. | acute exacerbations of chronic obstructive pulmonary disease (copd) are a major source of morbidity and contribute significantly to healthcare costs. although bacterial infections are implicated in nearly 50% of exacerbations, only a handful of pathogens have been consistently identified in copd airways, primarily by culture-based methods, and the bacterial microbiota in acute exacerbations remains largely uncharacterized. the aim of this study was to comprehensively profile airway bacterial com ... | 2010 | 20141328 |
| complete genome sequence and comparative genomics of a novel myxobacterium myxococcus hansupus. | myxobacteria, a group of gram-negative aerobes, belong to the class δ-proteobacteria and order myxococcales. unlike anaerobic δ-proteobacteria, they exhibit several unusual physiogenomic properties like gliding motility, desiccation-resistant myxospores and large genomes with high coding density. here we report a 9.5 mbp complete genome of myxococcus hansupus that encodes 7,753 proteins. phylogenomic and genome-genome distance based analysis suggest that myxococcus hansupus is a novel member of ... | 2016 | 26900859 |
| natural product-based inhibitors of hypoxia-inducible factor-1 (hif-1). | the transcription factor hypoxia-inducible factor-1 (hif-1) regulates the expression of more than 70 genes involved in cellular adaptation and survival under hypoxic stress. activation of hif-1 is associated with numerous physiological and pathological processes that include tumorigenesis, vascular remodeling, inflammation, and hypoxia/ischemia-related tissue damage. clinical studies suggested that hif-1 activation correlates directly with advanced disease stages and treatment resistance among c ... | 2006 | 16515532 |
| tie me up, tie me down: inhibiting rna polymerase. | mechanistic understanding of antibiotic action can yield crucial insights that aid in the design of new antibiotics. in this issue, mukhopadhyay et al. (2008) uncover the mechanism by which the antibiotic myxopyronin inhibits bacterial rna polymerase, suggesting a new target region in rna polymerase for inhibitor design. | 2008 | 18957193 |
| new target for inhibition of bacterial rna polymerase: 'switch region'. | a new drug target - the 'switch region' - has been identified within bacterial rna polymerase (rnap), the enzyme that mediates bacterial rna synthesis. the new target serves as the binding site for compounds that inhibit bacterial rna synthesis and kill bacteria. since the new target is present in most bacterial species, compounds that bind to the new target are active against a broad spectrum of bacterial species. since the new target is different from targets of other antibacterial agents, com ... | 2011 | 21862392 |
| structure-based ligand design of novel bacterial rna polymerase inhibitors. | bacterial rna polymerase (rnap) is essential for transcription and is an antibacterial target for small molecule inhibitors. the binding region of myxopyronin b (myxb), a bacterial rnap inhibitor, offers the possibility of new inhibitor design. the molecular design program sprout has been used in conjunction with the x-ray cocrystal structure of thermus thermophilus rnap with myxb to design novel inhibitors based on a substituted pyridyl-benzamide scaffold. a series of molecules, with molecular ... | 2011 | 24900260 |
| antibiotics trapping transcription initiation intermediates: to melt or to bend, what's first? | promoter dna melting, culminating in the loading of the single-stranded dna template into the rna polymerase active site, is a key step in transcription initiation. recently, the first transcription inhibitors found to block distinct steps of promoter melting were characterized. here, the impact of these studies is discussed with respect to the current models of transcription initiation. | 2011 | 21468230 |
| frequency, spectrum, and nonzero fitness costs of resistance to myxopyronin in staphylococcus aureus. | the antibiotic myxopyronin (myx) functions by inhibiting bacterial rna polymerase (rnap). the binding site on rnap for myx-the rnap "switch region sw1/sw2 subregion"-is different from the binding site on rnap for the rnap inhibitor currently used in broad-spectrum antibacterial therapy, rifampin (rif). here, we report the frequency, spectrum, and fitness costs of myx resistance in staphylococcus aureus. the resistance rate for myx is 4 × 10(-8) to 7 × 10(-8) per generation, which is equal within ... | 2012 | 23006749 |
| intra- and interprotein phosphorylation between two-hybrid histidine kinases controls myxococcus xanthus developmental progression. | histidine-aspartate phosphorelay signaling systems are used to couple stimuli to cellular responses. a hallmark feature is the highly modular signal transmission modules that can form both simple "two-component" systems and sophisticated multicomponent systems that integrate stimuli over time and space to generate coordinated and fine-tuned responses. the deltaproteobacterium myxococcus xanthus contains a large repertoire of signaling proteins, many of which regulate its multicellular developmen ... | 2012 | 22661709 |
| complete genome sequence of the fruiting myxobacterium corallococcus coralloides dsm 2259. | corallococcus coralloides, like most other myxobacteria, undergoes a developmental program culminating in the formation of fruiting bodies. c. coralloides fruiting bodies are morphologically distinct from those of other fruiting myxobacteria for which full-length genome sequences are available. the genome sequence of the 10.0-mb c. coralloides genome is presented herein. | 2012 | 22582372 |
| identification and characterization of a putative arginine kinase homolog from myxococcus xanthus required for fruiting body formation and cell differentiation. | arginine kinases catalyze the reversible transfer of a high-energy phosphoryl group from atp to l-arginine to form phosphoarginine, which is used as an energy buffer in insects, crustaceans, and some unicellular organisms. it plays an analogous role to that of phosphocreatine in vertebrates. recently, putative arginine kinases were identified in several bacterial species, including the social gram-negative soil bacterium myxococcus xanthus. it is still unclear what role these proteins play in ba ... | 2012 | 22389486 |
| cell contact-dependent outer membrane exchange in myxobacteria: genetic determinants and mechanism. | biofilms are dense microbial communities. although widely distributed and medically important, how biofilm cells interact with one another is poorly understood. recently, we described a novel process whereby myxobacterial biofilm cells exchange their outer membrane (om) lipoproteins. for the first time we report here the identification of two host proteins, traab, required for transfer. these proteins are predicted to localize in the cell envelope; and traa encodes a distant pa14 lectin-like dom ... | 2012 | 22511878 |
| carf mediates signaling by singlet oxygen, generated via photoexcited protoporphyrin ix, in myxococcus xanthus light-induced carotenogenesis. | blue light triggers carotenogenesis in the nonphototrophic bacterium myxococcus xanthus by inducing inactivation of an anti-σ factor, carr, and the consequent liberation of the cognate extracytoplasmic function (ecf) σ factor, carq. carf, the protein implicated earliest in the response to light, does not resemble any known photoreceptor. it interacts physically with carr and is required for its light-driven inactivation, but the mechanism is unknown. blue-light sensing in m. xanthus has been att ... | 2012 | 22267513 |
| functional identification of rubber oxygenase (roxa) in soil and marine myxobacteria. | the rubber oxygenase (roxa) of xanthomonas sp. strain 35y (roxa(xsp)) is so far the only known extracellular c-type diheme cytochrome that is able to cleave poly(cis-1,4-isoprene). all other rubber-degrading bacteria described are gram positive and employ a nonheme protein (latex-clearing protein [lcp]) for the postulated primary attack of polyisoprene. here, we identified roxa orthologs in the genomes of haliangium ochraceum, myxococcus fulvus, corallococcus coralloides, and chondromyces apicul ... | 2013 | 23934498 |
| antimicrobial peptides from marine proteobacteria. | after years of inadequate use and the emergence of multidrug resistant (mdr) strains, the efficiency of "classical" antibiotics has decreased significantly. new drugs to fight mdr strains are urgently needed. bacteria hold much promise as a source of unusual bioactive metabolites. however, the potential of marine bacteria, except for actinomycetes and cyanobacteria, has been largely underexplored. in the past two decades, the structures of several antimicrobial compounds have been elucidated in ... | 2013 | 24084784 |
| metagenomic analyses reveal phylogenetic diversity of carboxypeptidase gene sequences in activated sludge of a wastewater treatment plant in shanghai, china. | activated sludge of wastewater treatment plants carries a diverse microflora. however, up to 80-90 % of microorganisms in activated sludge cannot be cultured by current laboratory techniques, leaving an enzyme reservoir largely unexplored. in this study, we investigated carboxypeptidase diversity in activated sludge of a wastewater treatment plant in shanghai, china, by a culture-independent metagenomic approach. three sets of consensus degenerate hybrid oligonucleotide primers (codehops) target ... | 2013 | 24860282 |
| metagenomic analyses reveal phylogenetic diversity of carboxypeptidase gene sequences in activated sludge of a wastewater treatment plant in shanghai, china. | activated sludge of wastewater treatment plants carries a diverse microflora. however, up to 80-90 % of microorganisms in activated sludge cannot be cultured by current laboratory techniques, leaving an enzyme reservoir largely unexplored. in this study, we investigated carboxypeptidase diversity in activated sludge of a wastewater treatment plant in shanghai, china, by a culture-independent metagenomic approach. three sets of consensus degenerate hybrid oligonucleotide primers (codehops) target ... | 2013 | 24860282 |
| isolation and identification of myxobacteria from saline-alkaline soils in xinjiang, china. | fifty-eight terrestrial and salt-tolerant myxobacteria were isolated from the saline-alkaline soils collected from xinjiang, china. based on the morphologies and the 16s rrna gene sequences, these isolates were assigned into 6 genera, myxococcus, cystobacter, corallococcus, sorangium, nannocystis and polyangium. all the strains grew better with 1% nacl than without nacl. some myxococcus strains were able to grow at 2% nacl concentration, suggesting that these strains may be particular type of te ... | 2013 | 23936436 |
| direct live imaging of cell-cell protein transfer by transient outer membrane fusion in myxococcus xanthus. | in bacteria, multicellular behaviors are regulated by cell-cell signaling through the exchange of both diffusible and contact-dependent signals. in a multicellular context, myxococcus cells can share outer membrane (om) materials by an unknown mechanism involving the traab genes and gliding motility. using live imaging, we show for the first time that transient contacts between two cells are sufficient to transfer om materials, proteins and lipids, at high efficiency. transfer was associated wit ... | 2013 | 23898400 |
| extraordinary expansion of a sorangium cellulosum genome from an alkaline milieu. | complex environmental conditions can significantly affect bacterial genome size by unknown mechanisms. the so0157-2 strain of sorangium cellulosum is an alkaline-adaptive epothilone producer that grows across a wide ph range. here, we show that the genome of this strain is 14,782,125 base pairs, 1.75-megabases larger than the largest bacterial genome from s. cellulosum reported previously. the total 11,599 coding sequences (cdss) include massive duplications and horizontally transferred genes, r ... | 2013 | 23812535 |
| draft genome of a type 4 pilus defective myxococcus xanthus strain, dzf1. | myxococcus xanthus is a member of the myxococcales order within the deltaproteobacterial subdivision. here, we report the whole-genome shotgun sequence of the type iv pilus (t4p) defective strain dzf1, which includes many genes found in strain dz2 but absent from strain dk1622. | 2013 | 23788552 |
| draft genome sequence of myxococcus xanthus wild-type strain dz2, a model organism for predation and development. | myxococcus xanthus is a member of the myxococcales order within the deltaproteobacteria subdivision. the myxobacteria reside in soil, have relatively large genomes, and display complex life cycles. here, we report the whole-genome shotgun sequence of strain dz2, which includes unique genes not found previously in strain dk1622. | 2013 | 23661486 |
| a new member of the 4-methylideneimidazole-5-one-containing aminomutase family from the enediyne kedarcidin biosynthetic pathway. | 4-methylideneimidazole-5-one (mio)-containing aminomutases catalyze the conversion of l-α-amino acids to β-amino acids with either an (r) or an (s) configuration. l-phenylalanine and l-tyrosine are the only two natural substrates identified to date. the enediyne chromophore of the chromoprotein antitumor antibiotic kedarcidin (ked) harbors an (r)-2-aza-3-chloro-β-tyrosine moiety reminiscent of the (s)-3-chloro-5-hydroxy-β-tyrosine moiety of the c-1027 enediyne chromophore, the biosynthesis of wh ... | 2013 | 23633564 |