| initiation factor 2 of myxococcus xanthus, a large version of prokaryotic translation initiation factor 2. | we have isolated the structural gene for translation initiation factor if2 (infb) from the myxobacterium myxococcus xanthus. the gene (3.22 kb) encodes a 1,070-residue protein showing extensive homology within its g domain and c terminus to the equivalent regions of if2 from escherichia coli. the protein cross-reacts with antibodies raised against e. coli if2 and was able to complement an e. coli infb mutant. the m. xanthus protein is the largest if2 known to date. this is essentially due to a l ... | 2001 | 11114918 |
| pattern formation: fruiting body morphogenesis in myxococcus xanthus. | when myxococcus xanthus cells are exposed to starvation, they respond with dramatic behavioral changes. the expansive swarming behavior stops and the cells begin to aggregate into multicellular fruiting bodies. the cell-surface-associated c-signal has been identified as the signal that induces aggregation. recently, several of the components in the c-signal transduction pathway have been identified and behavioral analyses are beginning to reveal how the c-signal modulates cell behavior. together ... | 2000 | 11121786 |
| ihfa gene of the bacterium myxococcus xanthus and its role in activation of carotenoid genes by blue light. | myxococcus xanthus responds to blue light by producing carotenoids. several regulatory genes are known that participate in the light action mechanism, which leads to the transcriptional activation of the carotenoid genes. we had already reported the isolation of a carotenoid-less, tn5-induced strain (mr508), whose mutant site was unlinked to the indicated regulatory genes. here, we show that omegamr508::tn5 affects all known light-inducible promoters in different ways. it blocks the activation o ... | 2001 | 11133949 |
| myxococcus xanthus moka encodes a histidine kinase-response regulator hybrid sensor required for development and osmotic tolerance. | a gene, moka, encoding a protein with similarities to histidine kinase-response regulator hybrid sensor, was cloned from a myxococcus xanthus genomic library. the predicted moka gene product was found to contain three domains: an amino-terminal input domain, a central transmitter domain, and a carboxy-terminal receiver domain. moka mutants placed under starvation conditions exhibited reduced sporulation. mutation of moka also caused marked growth retardation at high osmolarity. these results ind ... | 2001 | 11157925 |
| drosophila as a model host for pseudomonas aeruginosa infection. | using the fruit fly drosophila melanogaster as model host, we have identified mutants of the bacterium pseudomonas aeruginosa with reduced virulence. strikingly, all strains strongly impaired in fly killing also lacked twitching motility; most such strains had a mutation in pilghijkl chpabcde, a gene cluster known to be required for twitching motility and potentially encoding a signal transduction system. the pil chp genes appear to control the expression of additional virulence factors, however ... | 2001 | 11157963 |
| identification and characterization of spdr mutations that bypass the bsga protease-dependent regulation of developmental gene expression in myxococcus xanthus. | the bsga protease of myxococcus xanthus is an intracellular protease closely related to the lon protease of escherichia coli. bsga is required for normal levels of developmentally induced gene expression. in this report, we describe the identification of mutations that suppress the developmental defect of bsga mutants. these mutations localized to the spdr gene (suppressor protease deficiency regulator) that appears to play a role in the regulation of early developmental gene expression. mutatio ... | 2001 | 11169116 |
| the myxococcus xanthus wbgb gene encodes a glycosyltransferase homologue required for lipopolysaccharide o-antigen biosynthesis. | myxococcus xanthus is a gram-negative soil bacterium that initiates a complex developmental program in response to starvation. a transposon insertion (tn5-lac omega109) mutant with developmental deficiencies was isolated and characterized in this study. a strain containing this insertion mutation in an otherwise wild-type background showed delayed developmental aggregation for about 12 h and sporulated at 1-2% of the wild-type level. tn5-lac omega109 was found to have disrupted the m. xanthus wb ... | 2000 | 11195095 |
| characterization of the mac-1 gene encoding a putative abc transporter from myxococcus xanthus. | the mac-1 gene of myxococcus xanthus ta, an antibiotic ta producer, encoded a protein with strong sequence similarity to the antibiotic atp-binding cassette (abc) transporter for macrolide antibiotics. the mac-1 gene encoding protein (mac-1) had two atp-binding domains containing walker a and b motifs, and no hydrophobic transmembrane regions. insertional inactivation of mac-1 caused enhanced sensitivity to oleandomycin, a macrolide antibiotic, while the mac-1 mutant showed normal export of anti ... | 2001 | 11226873 |
| lipid chemotaxis and signal transduction in myxococcus xanthus. | the lipid phosphatidylethanolamine (pe) is the first chemoattractant to be described for a surface-motile bacterium. in myxococcus xanthus, the specific activity of pe is determined by its fatty acid components. two active species have been identified: dilauroyl pe and dioleoyl pe. excitation to dilauroyl pe requires fibril appendages and the presence of two cytoplasmic chemotaxis systems, of which one (dif) appears to mediate excitation and the other (frz) appears to mediate adaptation. a possi ... | 2001 | 11239790 |
| frozen motion of gliding bacteria outlines inherent features of the motility apparatus. | high-resolution data of actively gliding wild-type bacteria of four different species and of four different gliding mutants of myxococcus xanthus were obtained from scanning electron micrographs. by shock freezing and freeze drying, motility-associated surface patterns could be fixed and consequently distinct intermediate states of motion could be observed for the first time. it is shown that these topographic patterns are immediately lost when gliding motility is stopped by blocking the respira ... | 2001 | 11283289 |
| binding of nucleotides to nucleoside diphosphate kinase: a calorimetric study. | the source of affinity for substrates of human nucleoside diphosphate (ndp) kinases is particularly important in that its knowledge could be used to design more effective antiviral nucleoside drugs (e.g., azt). we carried out a microcalorimetric study of the binding of enzymes from two organisms to various nucleotides. isothermal titration calorimetry has been used to characterize the binding in terms of delta g degrees, delta h degrees and delta s degrees. thermodynamic parameters of the intera ... | 2001 | 11294625 |
| pph1 from myxococcus xanthus is a protein phosphatase involved in vegetative growth and development. | myxococcus xanthus is a gram-negative bacterium with a complex life cycle that includes vegetative swarming on rich medium and, upon starvation, aggregation to form fruiting bodies containing spores. both of these behaviours require multiple ser/thr protein kinases. in this paper, we report the first ser/thr protein phosphatase gene, pph1, from m. xanthus. dna sequence analysis of pph1 indicates that it encodes a protein of 254 residues (mr = 28 308) with strong homology to eukaryotic pp2c phosp ... | 2001 | 11298281 |
| c-signal: a cell surface-associated morphogen that induces and co-ordinates multicellular fruiting body morphogenesis and sporulation in myxococcus xanthus. | in myxococcus xanthus, morphogenesis of multicellular fruiting bodies and sporulation are co-ordinated temporally and spatially. csga mutants fail to synthesize the cell surface-associated c-signal and are unable to aggregate and sporulate. we report that csga encodes two proteins, a 25 kda species corresponding to full-length csga protein and a 17 kda species similar in size to c-factor protein, which has been shown previously to have c-signal activity. by systematically varying the accumulatio ... | 2001 | 11298283 |
| a fluorescent sensor of the phosphorylation state of nucleoside diphosphate kinase and its use to monitor nucleoside diphosphate concentrations in real time. | a sensor for purine nucleoside diphosphates in solution based on nucleoside diphosphate kinase (ndpk) has been developed. a single cysteine was introduced into the protein and labeled with the environmentally sensitive fluorophore, n-[2-(iodoacetamido)ethyl]-7-diethylaminocoumarin-3-carboxamide. the resultant molecule shows a 4-fold fluorescence increase when phosphorylated on his117; this phosphorylation is on the normal reaction pathway of the enzyme. the emission maximum of the phosphoenzyme ... | 2001 | 11305926 |
| sigb, sigc, and sige from myxococcus xanthus homologous to sigma32 are not required for heat shock response but for multicellular differentiation. | myxococcus xanthus has been known to have multiple sigma factors which are considered to play important roles in regulation of gene expression in development. a new gene encoding a putative sigma factor, sige, was cloned by using a degenerate oligonucleotide corresponding to the conserved region 2.2 of m. xanthus siga. in the 2.0-kb nucleotide sequence, an open reading frame consisting of 280 amino acid residues was identified. the amino acid sequence of sige shows high similarity to heat shock ... | 2001 | 11321585 |
| mgla and mglb of treponema denticola; similarity to abc transport and spa genes. | the mgla and mglb genes (td-mgla and td-mglb) of the oral spirochete treponema denticola were sequenced. these two t. denticola genes are highly homologous to the e. coli and treponema pallidum mgla and mglb genes which are part of the three gene beta-methylgalactoside transport operon, mglbac. both td-mgla and td-mglb are also homologous to the high affinity abc-type transporters for ribose and arabinose, and surface presentation antigens (spa) locus, part of the type iii secretion systems in e ... | 2000 | 11328650 |
| solution structure, backbone dynamics and chitin binding of the anti-fungal protein from streptomyces tendae tu901. | afp1 is a recently discovered anti-fungal, chitin-binding protein from streptomyces tendae tü901. mature afp1 comprises 86 residues and exhibits limited sequence similarity to the cellulose-binding domains of bacterial cellulases and xylanases. no similarity to the cys and gly-rich domains of plant chitin-binding proteins (e.g. agglutinins, lectins, hevein) is observed. afp1 is the first chitin-binding protein from a bacterium for which anti-fungal activity was shown. here, we report the three-d ... | 2001 | 11350173 |
| the act operon controls the level and time of c-signal production for myxococcus xanthus development. | the c-signal is a morphogen that controls the assembly of fruiting bodies and the differentiation of myxospores. production of this signal, which is encoded by the csga gene, is regulated by the act operon of four genes that are co-transcribed from the same start site. the act a and act b genes regulate the maximum level of the c-signal, which never rises above one-quarter of the maximum wild-type level of csga protein in null mutants of either gene. the act a and act b mutants have the same dev ... | 2001 | 11359579 |
| routes for fructose utilization by escherichia coli. | there are three main routes for the utilization of fructose by escherichia coli. one (route a) predominates in the growth of wild-type strains. it involves the functioning of the phosphoenolpyruvate:glycose phosphotransferase system (pts) and a fructose operon, mapping at min. 48.7, containing genes for a membrane-spanning protein (frua), a 1-phosphofructose kinase (fruk) and a diphosphoryl transfer protein (frub), under negative regulation by a frur gene mapping at min. 1.9. a second route (rou ... | 2001 | 11361065 |
| sdek, a histidine kinase required for myxococcus xanthus development. | the sdek gene is essential to the myxococcus xanthus developmental process. we reported previously, based on sequence analysis (a. g. garza, j. s. pollack, b. z. harris, a. lee, i. m. keseler, e. f. licking, and m. singer, j. bacteriol. 180:4628--4637, 1998), that sdek appears to be a histidine kinase. in the present study, we have conducted both biochemical and genetic analyses to test the hypothesis that sdek is a histidine kinase. an sdek fusion protein containing an n-terminal polyhistidine ... | 2001 | 11371522 |
| direct observation of extension and retraction of type iv pili. | type iv pili are thin filaments that extend from the poles of a diverse group of bacteria, enabling them to move at speeds of a few tenths of a micrometer per second. they are required for twitching motility, e.g., in pseudomonas aeruginosa and neisseria gonorrhoeae, and for social gliding motility in myxococcus xanthus. here we report direct observation of extension and retraction of type iv pili in p. aeruginosa. cells without flagellar filaments were labeled with an amino-specific cy3 fluores ... | 2001 | 11381130 |
| chemotaxis genes, fibrils and pe taxis in myxococcus xanthus. | | 2001 | 11393181 |
| directed movement and surface-borne motility of myxococcus and pseudomonas. | | 2001 | 11398423 |
| heterologous expression of archaeal selenoprotein genes directed by the secis element located in the 3' non-translated region. | previous in silico analysis of selenoprotein genes in archaea revealed that the selenocysteine insertion (secis) motif necessary to recode uga with selenocysteine was not adjacent to the uga codon as is found in bacteria. rather, paralogous stem-loop structures are located in the 3' untranslated region (3' utr), reminiscent of the situation in eukarya. to assess the function of such putative secis elements, the methanococcus jannaschii mj0029 (frua, which encodes the a subunit of the coenzyme f4 ... | 2001 | 11401697 |
| facile enzymatic aldol reactions with dihydroxyacetone in the presence of arsenate. | aldol reactions of in situ formed dihydroxyacetone arsenate with different aldehydes were catalyzed by bacterial d-fructose-1,6-bisphosphate aldolase (frua). aldolases from bacteria were found to be much more stable and active than frua from rabbit muscle. arsenate acts as a phosphate mimic and can, in principle, be used in catalytic amounts. the use of inorganic arsenate and dihydroxyacetone afforded high yields with hydrophobic aldehydes. cosolvents increased the solubility of hydrophobic alde ... | 2001 | 11421774 |
| a novel gene from myxococcus xanthus that facilitates membrane translocation of an extracellular endoglucanase in escherichia coli? | expression in escherichia coli of the myxococcus xanthus gene cela, which encodes an extracellular endoglucanase, resulted in cela being distributed between cytoplasm, periplasm and membrane. the presence of an adjacent open reading frame downstream from the full cela gene, or the absence of a putative lipoprotein signal sequence, confined cela distribution to the periplasm and membrane, or to the cytoplasm and periplasm, respectively. | 2001 | 11446517 |
| genetic studies of mrp, a locus essential for cellular aggregation and sporulation of myxococcus xanthus. | under starvation conditions, myxococcus xanthus undergoes a complex developmental process which includes cellular aggregation and sporulation. a transposon insertion mutant (the tn5-omega280 mutant) with defects in both aggregation and sporulation was analyzed in this study. the tn5-omega280 mutant was found to have a disrupted ntrc-like response regulator designated myxococcus regulatory protein b (mrpb). further sequencing analyses revealed a histidine kinase homolog (mrpa) immediately upstrea ... | 2001 | 11466282 |
| alternate routes to conformational specificity in a greek key beta barrel protein. | the n-terminal domain of protein s, a greek key calcium-binding protein from myxococcus xanthus, forms an atypical molten globule in the calcium-free state. the structure of this state is characterized by significant conformational fluctuations, which are localized to a subdomain that is not contiguous along the polypeptide chain. the conformational instability of this subdomain appears to arise from repulsive electrostatic interactions of four acidic side chains that are clustered together but ... | 2001 | 11532002 |
| domain architecture of a high mobility group a-type bacterial transcriptional factor. | myxococcus xanthus transcriptional factor card participates in carotenogenesis and fruiting body formation. it is the only reported prokaryotic protein having adjacent "at-hook" dna-binding and acidic regions characteristic of eukaryotic high mobility group a (hmga) proteins. the latter are small, unstructured, nonhistone nuclear proteins that function as architectural factors to remodel dna and chromatin structure and modulate various dna binding activities. we find card to be predominantly dim ... | 2001 | 11533063 |
| microfossils from silicified stromatolitic carbonates of the upper proterozoic limestone-dolomite 'series', central east greenland. | silicified flake conglomerates and in situ stratiform stromatolites of the upper proterozoic (c. 700-800 ma) limestone-dolomite 'series', central east greenland, contain well preserved microfossils. five stratigraphic horizons within the 1200 m succession contain microbial mat assemblages, providing a broad palaeontological representation of late proterozoic peritidal mat communities. comparison of assemblages demonstrates that the taxonomy and diversity of mat builder, dweller, and allochthon ... | 1989 | 11538669 |
| bacterial gliding motility: multiple mechanisms for cell movement over surfaces. | the mechanisms responsible for bacterial gliding motility have been a mystery for almost 200 years. gliding bacteria move actively over surfaces by a process that does not involve flagella. gliding bacteria are phylogenetically diverse and are abundant in many environments. recent results indicate that more than one mechanism is needed to explain all forms of bacterial gliding motility. myxococcus xanthus "social gliding motility" and synechocystis gliding are similar to bacterial "twitching mot ... | 2001 | 11544349 |
| glycerol 3-phosphate inhibits swarming and aggregation of myxococcus xanthus. | we have cloned a gene of myxococcus xanthus with similarities to the permease for glycerol 3-phosphate (g3p) of other bacteria. expression of the gene increased significantly during the first hours of starvation. swarming of the wild-type strain was inhibited and aggregation was delayed by g3p. conversely, a deltaglpt strain aggregated even on rich medium. these results indicate that g3p may function to regulate the timing of aggregation in m. xanthus. | 2001 | 11567014 |
| an unusual beta-ketoacyl:acyl carrier protein synthase and acyltransferase motifs in tak, a putative protein required for biosynthesis of the antibiotic ta in myxococcus xanthus. | the antibiotic ta of myxococcus xanthus is produced by a type-i polyketide synthase mechanism. previous studies have indicated that ta genes are clustered within a 36-kb region. the chemical structure of ta indicates the need for several post-modification steps, which are introduced to form the final bioactive molecule. these include three c-methylations, an o-methylation and a specific hydroxylation. in this study, we describe the genetic analysis of tak, encoding a specific polyketide beta-ket ... | 2001 | 11583847 |
| radiation-mediated control of drug delivery. | clinical trials of radiotherapy to control drug delivery were initiated in 1999 at vanderbilt university. the initial studies exploited the findings that platelets are activated in tumor blood vessels after high-dose irradiation as used in radiosurgery and high-dose-rate brachytherapy. platelets labeled with 111in showed binding in tumor blood vessels. however, the platelet labeling process caused platelets to also accumulate in the spleen. that clinical trial was closed, and subsequent clinical ... | 2001 | 11586099 |
| heat-shock-induced proteins from myxococcus xanthus. | optimal conditions for two-dimensional gel electrophoresis of total cellular proteins from myxococcus xanthus were established. using these conditions, we analyzed protein patterns of heat-shocked m. xanthus cells. eighteen major spots and 15 minor spots were found to be induced by heat shock. from n-terminal sequences of 15 major spots, dnak, groel, groes, alkyl hydroperoxide reductase, aldehyde dehydrogenase, succinyl coenzyme a (coa) synthetase, 30s ribosomal protein s6, and atp synthase alph ... | 2001 | 11591671 |
| piecing together a puzzling pathway: new insights into c-signaling. | | 2001 | 11597427 |
| analyses of mrp genes during myxococcus xanthus development. | myxococcus xanthus is a gram-negative soil bacterium that undergoes development under starvation conditions. our previous study identified a new genetic locus, mrp, which is required for both fruiting body formation and sporulation. the locus encodes two transcripts: mrpab, which consists of a histidine kinase and an ntrc-like response regulator, and mrpc, a cyclic amp receptor protein family transcription activator. in this study, we used genetic and biochemical analyses to investigate the poss ... | 2001 | 11698359 |
| gida is an fad-binding protein involved in development of myxococcus xanthus. | a gene encoding a homologue of the escherichia coli gida protein (glucose-inhibited division protein a) lies immediately upstream of aglu, a gene encoding a wd-repeat protein required for motility and development in myxococcus xanthus. the gida protein of m. xanthus shares about 48% identity overall with the small (approximately equal to 450 amino acid) form of gida from eubacteria and about 24% identity overall with the large (approximately equal to 620 amino acid) form of gida from eubacteria ... | 2001 | 11703671 |
| identification of a developmental chemoattractant in myxococcus xanthus through metabolic engineering. | fruiting body formation of myxococcus xanthus requires the ordered migration of tens of thousands of cells by using a form of surface motility known as gliding and chemical signal(s) that have yet to be elucidated. directed movement is regulated by phosphatidylethanolamine (pe) purified from m. xanthus cell membranes. because the purified pe preparation contains a remarkably diverse mixture of fatty acids, metabolic engineering was used to elucidate the biologically active fatty acid component. ... | 2001 | 11717456 |
| light-induced carotenogenesis in myxococcus xanthus: evidence that cars acts as an anti-repressor of cara. | in the bacterium myxococcus xanthus, carotenoids are produced in response to illumination, as a result of expression of the crt carotenoid biosynthesis genes. the majority of crt genes are clustered in the crtebdc operon, which is repressed in the dark by cara. genetic data suggest that, in the light, cars is synthesized and achieves activation of the crtebdc operon by removing the repressive action of cara. as cars contains no known dna-binding motif, the relief of cara-mediated repression was ... | 2001 | 11722744 |
| lens crystallins and their microbial homologs: structure, stability, and function. | abg-crystallins are the major protein components in the vertebrate eye lens--a as a molecular chaperone and b and g as structural proteins. surprisingly, the latter two share some structural characteristics with a number of microbial stress proteins. the common denominator is not only the greek key topology of their polypeptide chains but also their high intrinsic stability, which, in certain microbial crystallin homologs, is further enhanced by high-affinity ca2+-binding. recent studies of natu ... | 2001 | 11724156 |
| transcriptional activation of a heat-shock gene, lond, of myxococcus xanthus by a two component histidine-aspartate phosphorelay system. | in vitro transcription of lond, a heat-shock gene from myxococcus xanthus, was stimulated in the presence of extract from heat-shocked cells. for this stimulation the upstream promoter region of lond was found to be essential. activation of lond transcription was also observed when extract from non-heat-shocked cells was heat treated in vitro at 42 degrees c for 10 min. a dna binding assay and footprinting analysis revealed that a factor(s) binds to the upstream region from -122 to -107 with res ... | 2002 | 11748231 |
| a repressor-antirepressor pair links two loci controlling light-induced carotenogenesis in myxococcus xanthus. | the light-inducible carb operon encodes all but one of the structural genes for carotenogenesis in myxococcus xanthus. it is transcriptionally controlled by two proteins expressed from two unlinked genetic loci: cars from the light-inducible carqrs operon, and cara from the light-independent cara operon. cara represses transcription from the carb promoter (p(b)) in the dark, and cars counteracts this on illumination. the cara sequence revealed a helix-turn-helix dna-binding motif of the type fou ... | 2002 | 11748235 |
| cell behavior in traveling wave patterns of myxobacteria. | cells in the early stages of starvation-induced fruiting body development migrate in a highly organized periodic pattern of equispaced accumulations that move as traveling waves. two sets of waves are observed moving in opposite directions with the same wavelength and speed. to learn how the behavior of individual cells contributes to the wave pattern, fluorescent cells were tracked within a rippling population. these cells exhibit at least three types of organized behavior. first, most cell mov ... | 2001 | 11752438 |
| pattern formation and traveling waves in myxobacteria: theory and modeling. | recent experiments have provided new quantitative measurements of the rippling phenomenon in fields of developing myxobacteria cells. these measurements have enabled us to develop a mathematical model for the ripple phenomenon on the basis of the biochemistry of the c-signaling system, whereby individuals signal by direct cell contact. the model quantitatively reproduces all of the experimental observations and illustrates how intracellular dynamics, contact-mediated intercellular communication, ... | 2001 | 11752439 |
| act operon control of developmental gene expression in myxococcus xanthus. | cell-bound c-signal guides the building of a fruiting body and triggers the differentiation of myxospores. earlier work has shown that transcription of the csga gene, which encodes the c-signal, is directed by four genes of the act operon. to see how expression of the genes encoding components of the aggregation and sporulation processes depends on c-signaling, mutants with loss-of-function mutations in each of the act genes were investigated. these mutations were found to have no effect on gene ... | 2002 | 11807078 |
| characterization and description of anaeromyxobacter dehalogenans gen. nov., sp. nov., an aryl-halorespiring facultative anaerobic myxobacterium. | five strains were isolated which form a physiologically and phylogenetically coherent group of chlororespiring microorganisms and represent the first taxon in the myxobacteria capable of anaerobic growth. the strains were enriched and isolated from various soils and sediments based on their ability to grow using acetate as an electron donor and 2-chlorophenol (2-cph) as an electron acceptor. they are slender gram-negative rods with a bright red pigmentation that exhibit gliding motility and form ... | 2002 | 11823233 |
| classification of the caspase-hemoglobinase fold: detection of new families and implications for the origin of the eukaryotic separins. | a comprehensive sequence and structural comparative analysis of the caspase-hemoglobinase protein fold resulted in the delineation of the minimal structural core of the protease domain and the identification of numerous, previously undetected members, including a new protease family typified by the hetf protein from the cyanobacterium nostoc. the first bacterial homologs of legumains and hemoglobinases were also identified. most proteins containing this fold are known or predicted to be active p ... | 2002 | 11835511 |
| pattern formation by a cell surface-associated morphogen in myxococcus xanthus. | in response to starvation, an unstructured population of identical myxococcus xanthus cells rearranges into an asymmetric, stable pattern of multicellular fruiting bodies. central to this pattern formation process are changes in organized cell movements from swarming to aggregation. aggregation is induced by the cell surface-associated c-signal. to understand how aggregation is accomplished, we have analyzed how c-signal modulates cell behavior. we show that c-signal induces a motility response ... | 2002 | 11842199 |
| bypass of a- and b-signaling requirements for myxococcus xanthus development by mutations in spdr. | mutations in spdr, previously reported to bypass the developmental requirement for b-signaling in myxococcus xanthus, also bypass the requirement for a-signaling but not c-, d-, or e-signaling. mutations in spdr restored nearly wild-type levels of sporulation to representative a-signal-deficient mutants carrying asga476, asgb480, and asgc767 and improved the quality of fruiting body formation in the asgb480 mutant. the defect in a-factor production by the asgb480 mutant was not restored in the s ... | 2002 | 11844778 |
| mapping of myxococcus xanthus social motility dsp mutations to the dif genes. | myxococcus xanthus dsp and dif mutants have similar phenotypes in that they are deficient in social motility and fruiting body development. we compared the two loci by genetic mapping, complementation with a cosmid clone, dna sequencing, and gene disruption and found that 16 of the 18 dsp alleles map to the dif genes. another dsp allele contains a mutation in the sglk gene. about 36.6 kb around the dsp-dif locus was sequenced and annotated, and 50% of the genes are novel. | 2002 | 11844780 |
| mlpb, a gene encoding a new lipoprotein in myxococcus xanthus. | to search for and study the genes involved in the regulation of phosphate in the soil developmental bacterium myxococcus xanthus. | 2002 | 11849337 |
| the devt protein stimulates synthesis of frua, a signal transduction protein required for fruiting body morphogenesis in myxococcus xanthus. | fruiting body formation in myxococcus xanthus involves three morphologic stages---rippling, aggregation, and sporulation---all of which are induced by the cell surface-associated c-signal. we analyzed the function of the devt protein, a novel component in the c-signal response pathway. a mutant carrying an in-frame deletion in the devt gene displays delayed aggregation and a cell autonomous sporulation defect, whereas it remains rippling proficient. to further define the function of devt, the me ... | 2002 | 11872704 |
| an extracellular matrix-associated zinc metalloprotease is required for dilauroyl phosphatidylethanolamine chemotactic excitation in myxococcus xanthus. | an extracellular matrix connects bacteria that live in organized assemblages called biofilms. while the role of the matrix in the regulation of cell behavior has not been extensively examined in bacteria, we suggest that, like mammalian cells, the matrix facilitates cell-cell interactions involved with regulation of cohesion, motility, and sensory transduction. the extracellular matrix of the soil bacterium myxococcus xanthus is essential for biofilm formation and fruiting body development. the ... | 2002 | 11872719 |
| how myxobacteria glide. | many microorganisms, including myxobacteria, cyanobacteria, and flexibacteria, move by gliding. although gliding always describes a slow surface-associated translocation in the direction of the cell's long axis, it can result from two very different propulsion mechanisms: social (s) motility and adventurous (a) motility. the force for s motility is generated by retraction of type 4 pili. a motility may be associated with the extrusion of slime, but evidence has been lacking, and how force might ... | 2002 | 11882287 |
| role for vitamin b(12) in light induction of gene expression in the bacterium myxococcus xanthus. | a light-inducible promoter (p(b)) drives the carb operon (carotenoid genes) of the bacterium myxococcus xanthus. a gene encoding a regulator of carotenoid biosynthesis was identified by studying mutant strains carrying a transcriptional fusion to p(b) and deletions in three candidate genes. our results prove that the identified gene, named cara, codes for a repressor of the p(b) promoter in the dark. they also show that the cara gene product does not participate in the light activation of two ot ... | 2002 | 11914353 |
| optimizing the heterologous production of epothilone d in myxococcus xanthus. | the heterologous production of epothilone d in myxococcus xanthus was improved by 140-fold from an initial titer of 0.16 mg/l with the incorporation of an adsorber resin, the identification of a suitable carbon source, and the implementation of a fed-batch process. to reduce the degradation of epothilone d in the basal medium, xad-16 (20 g/l) was added to stabilize the secreted product. this greatly facilitated its recovery and enhanced the yield by three-fold. the potential of using oils as a c ... | 2002 | 11920444 |
| modulation of epothilone analog production through media design. | recently, the epothilone polyketide synthase (pks) was successfully introduced into a heterologous production host for the large-scale production of epothilone d. we have found that at least three other epothilones can also be produced as the major fermentation product of this recombinant strain by supplementation of specific substrates to the production media. addition of acetate or propionate to the media results in modulation of the epothilone d:c ratio, whereas addition of l-serine with eith ... | 2002 | 11938466 |
| [effect of various storage methods on the viability of myxobacteria]. | viability of myxobacteria strains myxococcus xanthus uncm 10041, polyangium cellulosum uncm 10043, archangium gephyra uncm 10001 stored by the methods of lyophilization, cryoconservation, drying on paper discs, suspending in distilled water or physiological solution under a layer of mineral oil. the best results on viability preservation of all three studied strains were obtained when using the method of cryoconservation. it has been shown that the strains m. xanthus and a. gephyra preserve the ... | 2001 | 11944333 |
| large-scale isolation and crystallization of epothilone d from myxococcus xanthus cultures. | the introduction of the epothilone polyketide synthase (pks) into myxococcus xanthus has enabled the heterologous production of epothilone d (1) on a large scale. to isolate this valuable product from the fermentation medium, an economical, scalable, and high-yielding purification process was developed. with the crystallization of 1 from a binary solvent system that consisted of ethanol and water, the product was recovered as white crystals with a final purity of > or =97% (w/w). this is the fir ... | 2002 | 11975503 |
| rescue of social motility lost during evolution of myxococcus xanthus in an asocial environment. | replicate populations of the social bacterium myxococcus xanthus underwent extensive evolutionary adaptation to an asocial selective environment (liquid batch culture). all 12 populations showed partial or complete loss of their social (s) motility function after 1,000 generations of evolution. mutations in the pil gene cluster (responsible for type iv pilus biogenesis and function) were found to be at least partially responsible for the loss of s motility in the majority of evolved lines. resto ... | 2002 | 11976301 |
| role of frua and csga genes in gene expression during development of myxococcus xanthus. analysis by two-dimensional gel electrophoresis. | two genes, frua and csga, encoding a putative transcription factor and c-factor, respectively, are essential for fruiting body formation of myxococcus xanthus. to investigate the role of frua and csga genes in developmental gene expression, developing cells as well as vegetative cells of m. xanthus wild-type, frua::tc, and csga731 strains were pulse-labeled with [(35)s]methionine, and the whole cell proteins were analyzed using two-dimensional immobilized ph gradient/sds-page. differences in pro ... | 2002 | 11997385 |
| identification of the omega4514 regulatory region, a developmental promoter of myxococcus xanthus that is transcribed in vitro by the major vegetative rna polymerase. | omega4514 is the site of a tn5 lac insertion in the myxococcus xanthus genome that fuses lacz expression to a developmentally regulated promoter. dna upstream of the insertion site was cloned, and the promoter was localized. the promoter resembles vegetative promoters in sequence, and sigma(a) rna polymerase, the major form of rna polymerase in growing m. xanthus, initiated transcription from this promoter in vitro. two complete open reading frames were identified downstream of the promoter and ... | 2002 | 12029052 |
| an adenylyl cyclase, cyaa, of myxococcus xanthus functions in signal transduction during osmotic stress. | an adenylyl cyclase gene (cyaa) present upstream of an osmosensor protein gene (moka) was isolated from myxococcus xanthus. cyaa encoded a polypeptide of 843 amino acids with a predicted molecular mass of 91,187 da. the predicted cyaa gene product had structural similarity to the receptor-type adenylyl cyclases that are composed of an amino-terminal sensor domain and a carboxy-terminal catalytic domain of adenylyl cyclase. in reverse transcriptase pcr experiments, the transcript of the cyaa gene ... | 2002 | 12057952 |
| a novel biosynthetic pathway providing precursors for fatty acid biosynthesis and secondary metabolite formation in myxobacteria. | short chain carboxylic acids are well known as the precursors of fatty acid and polyketide biosynthesis. iso-fatty acids, which are important for the control of membrane fluidity, are formed from branched chain starter units (isovaleryl-coa and isobutyryl-coa), which in turn are derived from the degradation of leucine and valine, respectively. branched chain carboxylic acids are also employed as starter molecules for the biosynthesis of secondary metabolites, e.g. the therapeutically important a ... | 2002 | 12084727 |
| a new cytotoxic epothilone from modified polyketide synthases heterologously expressed in myxococcus xanthus. | a new epothilone, 10,11-didehydroepothilone d (5), was isolated from a strain of the heterologous host myxococcus xanthus genetically engineered to produce epothilone d (4). the structure of 5 was determined from nmr and ms data. the epothilone polyketide synthase was further modified in a recombinant m. xanthus strain to produce 5 as the major epothilone-related metabolite. the cytotoxicity of 5 against a panel of tumor cell lines, including several with multidrug resistance, and its effect on ... | 2002 | 12141877 |
| type iv pili and twitching motility. | twitching motility is a flagella-independent form of bacterial translocation over moist surfaces. it occurs by the extension, tethering, and then retraction of polar type iv pili, which operate in a manner similar to a grappling hook. twitching motility is equivalent to social gliding motility in myxococcus xanthus and is important in host colonization by a wide range of plant and animal pathogens, as well as in the formation of biofilms and fruiting bodies. the biogenesis and function of type i ... | 2002 | 12142488 |
| heterologous expression of epothilone biosynthetic genes in myxococcus xanthus. | epothilones are potential anticancer drugs that stabilize microtubules in a manner similar to paclitaxel (taxol). epothilones are produced from the myxobacterium sorangium cellulosum, which has a 16-h doubling time and produces only milligram-per-liter amounts of epothilone a and epothilone b. furthermore, genetic manipulation of s. cellulosum is difficult. to produce epothilones in a more genetically amenable and rapidly growing host, we chose the closely related and best-characterized myxobact ... | 2002 | 12183227 |
| characterization of bcsa mutations that bypass two distinct signaling requirements for myxococcus xanthus development. | the bsga protease is required for starvation-induced development in myxococcus xanthus. bypass suppressors of a bsga mutant were isolated to identify genes that may encode additional components of bsga protease-dependent regulation of development. strain m951 was isolated following tn5 mutagenesis of a bsga mutant and was capable of forming fruiting bodies and viable spores in the absence of the bsga protease. the tn5omega951 insertion was localized to a gene, bcsa, that encodes a protein that h ... | 2002 | 12193631 |
| a chew homologue is required for myxococcus xanthus fruiting body development, social gliding motility, and fibril biogenesis. | in bacteria with multiple sets of chemotaxis genes, the deletion of homologous genes or even different genes in the same operon can result in disparate phenotypes. myxococcus xanthus is a bacterium with multiple sets of chemotaxis genes and/or homologues. it was shown previously that difa and dife, encoding homologues of the methyl-accepting chemoreceptor protein (mcp) and the chea kinase, respectively, are required for m. xanthus social gliding (s) motility and development. both difa and dife m ... | 2002 | 12270823 |
| cloning and expression of a porphyromonas gingivalis gene for protoporphyrinogen oxidase by complementation of a hemg mutant of escherichia coli. | porphyromonas gingivalis, a bacterium implicated in periodontal pathogenesis, has a growth requirement for iron protoporphyrin ix. by complementation with a p. gingivalis 381 chromosomal dna library, we were able to isolate a clone that enhanced the poor growth of a hemg mutant of escherichia coli. the dna sequence analysis of this clone revealed three open reading frames (orfs). orf3 encoded a protein of 466 amino acids with a calculated molecular weight of 51 695 da. the deduced amino acid seq ... | 2002 | 12354210 |
| control of secondary metabolite congener distributions via modulation of the dissolved oxygen tension. | many secondary metabolites, including various polyketides, require complex enzymatic pathways for modification into their final biologically active forms. limitation of the dissolved oxygen supplied during cultivation of various microbial strains can decrease the activity of cytochrome p-450 monooxygenases required for the processing of pathway intermediates into their final forms, resulting in the accumulation of these intermediates as the primary products. here, a generalized oxygen-limited cu ... | 2002 | 12363340 |
| modeling alignment and movement of animals and cells. | schools of fish and flocks of birds are examples for groups of individuals moving in a highly organized way. individuals adapt their orientation and speed to that of their (nearest) neighbors. adaptation of orientation can also be found on the cellular and subcellular level and is called alignment. a model for alignment and movement is derived on the basis of reaction transport equations in one space dimension. existence of solutions is shown and long time behavior of the system is described. th ... | 2002 | 12373346 |
| development of a laser-induced cell lysis system. | a novel cell lysis system was developed that is based on laser-induced disruption of bacterial and yeast cells. it will find application as a rapid, efficient and clean sample preparation step in bioanalytical detection systems. using e. coli as our model analyte, we optimized cell lysis with respect to optimal laser wavelength, lowest energy input requirements, rna release from the cells, and potential protein damage. the optimized system was finally applied to the lysis of four additional micr ... | 2002 | 12373389 |
| the cyanobacterial pilt protein responsible for cell motility and transformation hydrolyzes atp. | the unicellular cyanobacterium, synechocystis sp. pcc 6803 is motile. a homologue of the pilt protein family, required for twitching motility in pseudomonas aeruginosa and social gliding motility in myxococcus xanthus, was found to be necessarily associated with cyanobacterial motility. the pilt1 (slr0161) mutant shows a pleotropic phenotype, defects in individual cell motility, and an increased number of long surface pili. furthermore, the mutant loses its ability of natural competency. these f ... | 2002 | 12407192 |
| analysis of dofa, a frua-dependent developmental gene, and its homologue, dofb, in myxococcus xanthus. | the developmentally regulated gene dofa, identified from pulse-labeling experiments by two-dimensional gel electrophoresis, and its homologue, dofb, were cloned and characterized in myxococcus xanthus. deletion of dofa and dofb did not affect the vegetative growth and development of m. xanthus. dofa was specifically expressed during development, while dofb expression was observed during vegetative growth and development. the dofa-lacz fusion was introduced into a frua mutant and a, b, c, d, and ... | 2002 | 12446630 |
| experimental social evolution with myxococcus xanthus. | genetically-based social behaviors are subject to evolutionary change in response to natural selection. numerous microbial systems provide not only the opportunity to understand the genetic mechanisms underlying specific social interactions, but also to observe evolutionary changes in sociality over short time periods. here we summarize experiments in which behaviors of the social bacterium myxococcus xanthus changed extensively during evolutionary adaptation to two relatively asocial laboratory ... | 2002 | 12448714 |
| activation of 6-phosphofructokinase via phosphorylation by pkn4, a protein ser/thr kinase of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium that exhibits a communal lifestyle during vegetative growth and multicellular development, forming fruiting bodies filled with spores. it contains at least 13 eukaryotic-like protein ser/thr kinases (pstks from pkn1 to pkn13). in the present report, we demonstrate that pkn4, the gene located 18 bp downstream of the gene for 6-phosphofructokinase (pfk), is a pstk for m. xanthus pfk (mx-pfk), the key regulatory enzyme in glycolysis. both pkn4 and mx- ... | 2002 | 12453221 |
| mgla, a small gtpase, interacts with a tyrosine kinase to control type iv pili-mediated motility and development of myxococcus xanthus. | the mgla gene encodes a 22 kda gtpase that is critical for single-cell (a) gliding, type iv pili-mediated (s) gliding and development of myxococcus xanthus. to identify components that interact with mgla to control these processes, second-site mutations that restore movement to non-motile mgla mutants were sought. an allele-specific extragenic suppressor of mgla8, named mas815 (mgla8 suppressor 15), was obtained. mas815 does not bypass the requirement for mgla, yet it restores type iv pili-media ... | 2002 | 12453225 |
| generating and exploiting polarity in bacteria. | bacteria are often highly polarized, exhibiting specialized structures at or near the ends of the cell. among such structures are actin-organizing centers, which mediate the movement of certain pathogenic bacteria within the cytoplasm of an animal host cell; organized arrays of membrane receptors, which govern chemosensory behavior in swimming bacteria; and asymmetrically positioned septa, which generate specialized progeny in differentiating bacteria. this polarization is orchestrated by comple ... | 2002 | 12471245 |
| a novel regulatory gene for light-induced carotenoid synthesis in the bacterium myxococcus xanthus. | myxococcus xanthus cells respond to blue light by producing carotenoids. light triggers a network of regulatory actions that lead to the transcriptional activation of the carotenoid genes. by screening the colour phenotype of a collection of tn5-lac insertion mutants, we have isolated a new mutant devoid of carotenoid synthesis. we map the transposon insertion, which co-segregates with the mutant phenotype, to a previously unknown gene designated here as carf. an in frame deletion within carf ca ... | 2003 | 12519205 |
| [expression, purification and characterization of frua, a transcription factor in myxococcus xanthus]. | frua is a transcription factor essential for the development of myxocoxccus xanthus. gene encoding frua with a poly-histidine tag was expressed in e. coli and simply purified by chromatography on nickel column. data from gel retardation assay suggest that frua regulates transcription of target genes in collaboration with other factors. | 2000 | 12548932 |
| [isolation of a development revertant of myxococus xamthus]. | frua::tc omega 5 is a development deficient strain of m. xamthus. transposon tnv was used to randomly mutagenize various sites of frua::tc omega 5 chromosome. fruiting body formation was restored in one tnv insertion mutant, designated xm1206. the tnv-inserted dna fragment from xm1206 chromosome was cloned, which may be served as a probe to isolate the corresponding allele from wild-type strain. | 2001 | 12549033 |
| [isolation and identification of myxobacteria]. | this paper reported that the authors isolated large numbers of myxobacteria from more than 100 samples collected in many places of china. more than 400 pure strains were obtained. these strains belonged to 10 genera of myxococcales. the most frequent genera isolated were myxococcus, sorangium, corallococcus, and cystobacter. melittangium was seldom isolated. no chondromyces and haploangium were found. | 2000 | 12549062 |
| [isolation and disruption analysis of a developmental gene of myxococcus xanthus]. | frub is an associated protein of frua, a transcription factor essential for the development of myxococcus xanthus. degenerate oligonucleotide primers were designed based on the n-terminal amino acid sequence of frub. using genomic dna as template, an approximate 110 bp fragment was generated and further served as a probe to screen a small genomic library of m. xanthus. a 4.5 kb saci fragment was isolated on the basis of its homology to the probe. disruption of frub delayed the morphogenesis of f ... | 2002 | 12557372 |
| [viability of lyophilized cells of myxococcus xanthus ukm 10041 and polyangium cellulosum ukm 10043 in presence of different antioxidants]. | it has been established that addition of antioxidants: cystamine, ionol, alpha-tocopherol to protective media (saccharose-gelatin agar) does not affect considerably viability of lyophillized cells of cultures myxococcus xanthus ucm 10041 and polyangium cellulosum ucm 10043. experimentally obtained and predicted data on the survival of cells of m. xanthus ucm 10041 and p. cellulosum ucm 10043 are the values of the same order which evidences for the possibility of the use of quick test for predict ... | 2002 | 12557487 |
| role of two novel two-component regulatory systems in development and phosphatase expression in myxococcus xanthus. | we have cloned a two-component regulatory system (phor2-phop2) of myxococcus xanthus while searching for genes that encode proteins with phosphatase activity, where phor2 encodes the histidine kinase and phop2 encodes the response regulator. a second system, phor3-phop3, was identified and isolated by using phop2 as a probe. these two systems are quite similar, sharing identities along the full-length proteins of 52% on the histidine kinases and 64% on the response regulators. the predicted stru ... | 2003 | 12562808 |
| cis elements necessary for developmental expression of a myxococcus xanthus gene that depends on c signaling. | cell contact-mediated c signaling coordinates morphogenesis and gene expression during development of myxococcus xanthus. one promoter that depends on c signaling for transcription lies upstream of omega4403, the site of a tn5 lac insertion in the genome. the omega4403 promoter has a c-box sequence centered at -49 bp that matches the consensus 5'-cayyccy-3', which is found in several c-signal-dependent promoters. mutational analysis of the omega4403 promoter region was performed to test the impo ... | 2003 | 12562812 |
| myxovirescin analogues via macrocyclic ring-closing metathesis. | a short, efficient route has been developed to analogues of myxovirescin using ring-closing metathesis whereby the antibacterial activity has been retained. | 2003 | 12565921 |
| chemosensory regulation of developmental gene expression in myxococcus xanthus. | the delta-proteobacterium myxococcus xanthus coordinates its motility during aggregation and fruiting body formation. while searching for chemotaxis genes in m. xanthus, we identified a third chemotaxis-like gene cluster, the che3 cluster, encoding homologs to two methyl-accepting chemotaxis proteins (mcps), a chew, a hybrid chea, a cheb, a cher, but no chey. mutations in mcp3a, mcp3b, and chea3 did not show obvious defects in motility or chemotaxis but did affect the timing of entry into develo ... | 2003 | 12566562 |
| construction and evaluation of a plasmid vector for the expression of recombinant lipoproteins in escherichia coli. | outer membrane lipoproteins are emerging as key targets for protective immunity to many bacterial pathogens. heterologous expression of lipoproteins in escherichia coli does not always result in high level expression of acylated recombinant protein. thus, these proteins do not take up their correct membrane topology and are lacking the immunostimulatory properties endowed by the lipid. to this end, we have designed a lipoprotein expression vector (pdump) that results in the production of fusion ... | 2003 | 12583997 |
| cell shape, division and development: the 2002 american society for microbiology (asm) conference on prokaryotic development. | in the last decade, the use of cytological techniques, together with the analysis of complete genomes, has dramatically advanced our understanding of bacterial development. work on several well-developed model systems such as bacillus subtilis, caulobacter crescentus, myxococcus xanthus and streptomyces spp., has provided us with an in-depth understanding of processes such as sporulation, multicellular behaviour and the bacterial cell cycle. at the same time, these studies have revolutionized ou ... | 2003 | 12603749 |
| the intp c-terminal segment is not required for excision of bacteriophage mx8 from the myxococcus xanthus chromosome. | during lysogenization of myxophage mx8, phage dna can be integrated into the attb site of the myxococcus xanthus chromosome through site-specific recombination. we previously demonstrated that the mx8 attp site is located within the coding sequence of the mx8 intp gene. hence, the integration of mx8 into the m. xanthus chromosome results in the conversion of the 112-amino-acid c-terminal segment of the intp protein into a 13-amino-acid c-terminal segment of a new protein, intr. to examine whethe ... | 2003 | 12644488 |
| coupling gene expression and multicellular morphogenesis during fruiting body formation in myxococcus xanthus. | a recurring theme in morphogenesis is the coupling of the expression of genes that drive morphogenesis and the morphogenetic process per se. this coupling ensures that gene expression and morphogenesis are carried out in synchrony. morphogenesis of the spore-filled fruiting bodies in myxococcus xanthus illustrates this coupling in the construction of a multicellular structure. fruiting body formation involves two stages: aggregation of cells into mounds and the position-specific sporulation of c ... | 2003 | 12657040 |
| light-induced carotenogenesis in myxococcus xanthus: functional characterization of the ecf sigma factor carq and antisigma factor carr. | illumination of dark-grown myxococcus xanthus with blue light leads to the induction of carotenoid synthesis. central to this response is the activation of the light-inducible promoter, pcarqrs, and the transcription of three downstream genes, carq, carr and cars. sequence analysis predicted that carq is a member of the ecf (extracytoplasmic function) subfamily of rna polymerase sigma factors, and that carr is an inner membrane protein. genetic analysis strongly implied that carr is an antisigma ... | 2003 | 12657058 |
| conservation of ornamental stone by myxococcus xanthus-induced carbonate biomineralization. | increasing environmental pollution in urban areas has been endangering the survival of carbonate stones in monuments and statuary for many decades. numerous conservation treatments have been applied for the protection and consolidation of these works of art. most of them, however, either release dangerous gases during curing or show very little efficacy. bacterially induced carbonate mineralization has been proposed as a novel and environmentally friendly strategy for the conservation of deterio ... | 2003 | 12676699 |
| extracellular polysaccharides mediate pilus retraction during social motility of myxococcus xanthus. | myxococcus xanthus is a gram-negative bacterium with a complex life cycle that includes vegetative swarming and fruiting-body formation. social (s)-motility (coordinated movement of large cell groups) requires both type iv pili and fibrils (extracellular matrix material consisting of polysaccharides and protein). little is known about the role of this extracellular matrix, or fibril material, in pilus-dependent motility. in this study, mutants lacking fibril material and, therefore, s-motility w ... | 2003 | 12704238 |
| lanthanum fixation by myxococcus xanthus: cellular location and extracellular polysaccharide observation. | myxococcus xanthus is a soil bacterium of the myxobacteria group and is abundant in almost all soils. its role in soil ecology is considered significant. one noteworthy characteristic of the bacterium is that it produces large quantities of extracellular polymeric substances (eps). it is also known that its biomass has the capacity to fix heavy metals. here it is reported that m. xanthus was able to accumulate 0.6 mmol of la per g of wet biomass and/or 0.99 mmol per g of dry biomass. transmissio ... | 2003 | 12729693 |
| regulation of frua expression during vegetative growth and development of myxococcus xanthus. | expression of the frua gene, encoding a putative transcription factor essential for fruiting body formation of myxococcus xanthus, is specifically activated during development. in the present study, we have analyzed the mechanism of the transcriptional regulation of frua expression. from gel retardation and footprinting assays using various frua regulatory regions as probes and competitors, a protein designated factor x was found to specifically bind to a sequence (xbs) located downstream of the ... | 2003 | 12736531 |
| novel developmental genes, frucd, of myxococcus xanthus: involvement of a cell division protein in multicellular development. | myxococcus xanthus is a gram-negative soil bacterium that undergoes multicellular development upon nutrient starvation. in the present study, two novel developmental genes, fruc and frud, of m. xanthus were identified and characterized. the frud protein has significant amino acid sequence similarity to the diviva proteins of many bacteria including bacillus subtilis. vegetative cells of the frud mutant exhibited a filamentous phenotype. the fruc and frud mutants displayed similar delayed-develop ... | 2003 | 12754229 |