Publications

territorial interactions between two myxococcus species.	it is unusual to find fruiting bodies of different myxobacteria occupying the same territory on natural samples. we were thus interested in determining whether myxobacteria establish territorial dominance and, if so, what the mechanism of that interaction is. we had previously observed that vegetative swarms of myxococcus xanthus and stigmatella aurantiaca placed close to each other on an agar surface initially merged but eventually separated. further studies indicated that these two species als ...	1994	8106334
the dsg gene of myxococcus xanthus encodes a protein similar to translation initiation factor if3.	the dsg mutants of myxococcus xanthus are defective in fruiting body development and sporulation, yet they grow normally. the deduced amino acid sequence of the dsg gene product is 50 and 51% identical to the amino acid sequence of translation initiation factor if3 of both escherichia coli and bacillus stearothermophilus, respectively. however, the dsg protein has a carboxy-terminal extension of 66 amino acids, which are absent from its e. coli and b. stearothermophilus homologs. the shine-dalga ...	1994	8113184
the myxococcus xanthus dsg gene product performs functions of translation initiation factor if3 in vivo.	the amino acid sequence of the dsg protein is 50% identical to that of translation initiation factor if3 of escherichia coli, the product of its infc gene. anti-e. coli if3 antibodies cross-react with the dsg protein. tn5 insertion mutations in dsg are lethal. when ample nutrients are available, however, certain dsg point mutant strains grow at the same rate as wild-type cells. under the starvation conditions that induce fruiting body development, these dsg mutants begin to aggregate but fail to ...	1994	8113185
sensory adaptation during negative chemotaxis in myxococcus xanthus.	myxococcus xanthus exhibits many tactic movements that require the frz signal transduction system, such as colony swarming and cellular aggregation during fruiting body formation. previously we demonstrated that the frz proteins control the chemotactic movements of m. xanthus (w. shi, t. köhler, and d. r. zusman, mol. microbiol. 9:601-611, 1993). however it was unclear from that study how chemotaxis might be achieved at the cellular level. in this study, we showed that m. xanthus cells not only ...	1994	8113194
unusual helix-containing greek keys in development-specific ca(2+)-binding protein s. 1h, 15n, and 13c assignments and secondary structure determined with the use of multidimensional double and triple resonance heteronuclear nmr spectroscopy.	multidimensional heteronuclear nmr spectroscopy has been used to determine almost complete backbone and side-chain 1h, 15n, and 13c resonance assignments of calcium loaded myxococcus xanthus protein s (173 residues). of the range of constant-time triple resonance experiments recorded, hncacb and cbca(co)nh, which correlate c alpha and c beta with backbone amide resonances of the same and the succeeding residue respectively, proved particularly useful in resolving assignment ambiguities created b ...	1994	8117701
identification of the myxococcus xanthus 59-kda membrane-associated gtp-binding protein as a proton-translocating atpase.	five gtp-binding proteins have been detected in myxococcus xanthus by photoaffinity cross-linking with azido-gtp [muñoz-dorado et al., j. biol. chem. 265 (1990a) 2702-2706]. one of them, the 59-kda membrane-associated gtp-binding protein, has been purified. the n-terminal sequence of a 10-kda fragment from the protease v8 digestion of the purified protein has been determined and degenerate oligodeoxyribonucleotides based on that sequence have been used to isolate and clone the gene that encodes ...	1994	8125291
evidence that asgb encodes a dna-binding protein essential for growth and development of myxococcus xanthus.	the asg mutants of myxococcus xanthus are defective in production of extracellular a-signal, which serves as a cell density signal for fruiting-body development. the dna sequence of asgb, one of the three asg genes, was determined. the deduced amino acid sequence of asgb contains a dna-binding helix-turn-helix motif near the c terminus. this putative helix-turn-helix is highly similar to the helix-turn-helix in region 4.2 of major sigma factors, which is the region that recognizes and interacts ...	1994	8144470
cloning and characterization of the soca locus which restores development to myxococcus xanthus c-signaling mutants.	the csga gene produces an intercellular signal during fruiting body formation of the myxobacterium myxococcus xanthus. sporulating pseudorevertants were isolated to allow us to understand the mechanism by which csga is perceived by cells and used to regulate developmental gene expression. two strains, ls559 and ls560, which have closely linked transposon insertions, soc-559 (formerly csp-559) and soc-560 (formerly csp-560), respectively, regained all the developmental behaviors lost by the csga ...	1994	8157590
incn plasmids mediate uv resistance and error-prone repair in pseudomonas aeruginosa pao.	while it seems likely that the ability to induce the expression of reca-controlled genes is nearly universal among the eubacteria, the expression of plasmid-borne ultraviolet (uv-resistance and mutagenesis genes seems to be species-dependent in a complex fashion. some plasmids encoding uv-resistance and mutagenesis functions only express these phenotypes in a select number of bacterial species. several uv-resistance plasmids that express these functions in escherichia coli are either unstable or ...	1994	8162189
structural similarity of a developmentally regulated bacterial spore coat protein to beta gamma-crystallins of the vertebrate eye lens.	the solution structure of ca(2+)-loaded protein s (m(r) 18,792) from the gram-negative soil bacterium myxococcus xanthus has been determined by multidimensional heteronuclear nmr spectroscopy. protein s consists of four internally homologous motifs, arranged to produce two domains with a pseudo-twofold symmetry axis, overall resembling a triangular prism. each domain consists of two topologically inequivalent "greek keys": the second and fourth motifs form standard greek keys, whereas the first ...	1994	8183906
cloning and characterization of the gene encoding the major sigma factor of stigmatella aurantiaca.	the gene (siga) encoding the major sigma factor of the myxobacterium, stigmatella aurantiaca, was cloned and sequenced. the deduced polypeptide contains 706 amino acids (aa) and has a deduced m(r) of 79,910. it exhibits four different aa sequence motifs which correlate with the conserved domains of the major sigma factors of myxococcus xanthus (sigma 80), escherichia coli (sigma 70) and bacillus subtilis (sigma 43). the sigma factor (sigma a) was detected in crude lysates of vegetative cells and ...	1994	8200526
new clusters of genes required for gliding motility in myxococcus xanthus.	gliding is the directed movement of cells across surfaces which occurs in the absence of external organelles such as flagella. gliding of the complex prokaryote, myxococcus xanthus, results from the action of two independent sets of genes known as the a (adventurous motility) and s (social motility) genes. strains with mutations in both systems (a-s-) do not spread on agar surfaces because both individual and group movement is abolished. to generate regulated, transcriptional fusions with operon ...	1994	7830561
sensor/response in myxococcus xanthus to attractants and repellents requires the frz signal transduction system.		1994	7855429
endogenous adp-ribosylation during development of the prokaryote myxococcus xanthus.	we examined endogenous adp-ribosylation of proteins during the development of the prokaryote myxococcus xanthus. in vivo and in vitro endogenous adp-ribosylation of m. xanthus proteins was detected and the profile of modified proteins changed during development. adenosine and nicotinamide inhibited adp-ribosylation. nicotinamide stimulated cells at low density to develop, in a manner similar to that previously observed with adenosine. higher concentrations of nicotinamide inhibited aggregation. ...	1994	7812456
[three-dimensional structure of an extracellular calcium binding protein, protein s. spore adhesion in myxobacteria].		1994	7884274
genes required for both gliding motility and development in myxococcus xanthus.	myxococcus xanthus cells can glide both as individual cells, dependent on adventurous motility (a motility), and as groups of cells, dependent upon social motility (s motility). tn5-lac mutagenesis was used to generate 16 new a- and nine new s- mutations. in contrast with previous results, we find that subsets of a- mutants are defective in fruiting body morphogenesis and/or myxospore differentiation. all s- mutants are defective in fruiting body morphogenesis, consistent with previous results. ...	1994	7891564
autolytic effect of the antibiotic produced by myxococcus coralloides d.	myxococcus coralloides d secretes an antibiotic, named corallolysin, when grown on a rich medium. when a critical concentration is reached, this antibiotic lyses the producer bacterium either during vegetative growth or during morphogenesis. corallolysin has not effect on resting cells nor on myxospores. the autolytic effect is caused by the early inhibition of rna synthesis.	1994	7539617
a new myxococcus xanthus gene cluster for the biosynthesis of the antibiotic saframycin mx1 encoding a peptide synthetase.	the gene cluster for the biosynthesis of the heterocyclic quinone antibiotic saframycin mx1 of myxococcus xanthus dm504/15 was inactivated and tagged by tn5 insertions. the tagged genes were cloned in escherichia coli and used to select overlapping cosmid clones spanning 58 kb of the m. xanthus genome. gene disruption experiments defined a > or = 18 kb contiguous dna region involved in saframycin biosynthesis. sequencing of part of this region revealed a large orf containing two 600-amino-acid d ...	1995	7551044
branched-chain fatty acids: the case for a novel form of cell-cell signalling during myxococcus xanthus development.	the esg locus is required for the formation of multicellular fruiting bodies and spores by the developmental bacterium myxococcus xanthus. studies have suggested that esg mutants are defective in the production of an essential signal (e-signal) used in cell-cell communication and that e-signalling is required for the expression of many developmental genes. recently we have determined that the esg locus encodes components of a branched-chain keto acid dehydrogenase, a multienzyme complex involved ...	1995	7565080
the esg locus of myxococcus xanthus encodes the e1 alpha and e1 beta subunits of a branched-chain keto acid dehydrogenase.	the esg locus of myxococcus xanthus appears to control the production of a signal that must be transmitted between cells for the completion of multicellular development. dna sequence analysis suggested that the esg locus encodes the e1 decarboxylase (composed of e1 alpha and e1 beta subunits) of a branched-chain keto acid dehydrogenase (bckad) that is involved in branched-chain amino acid (bcaa) metabolism. the properties of an esg::tn5 insertion mutant supported this conclusion. these propertie ...	1995	7565081
a cluster of structural and regulatory genes for light-induced carotenogenesis in myxococcus xanthus.	in the bacterium myxococcus xanthus, several genes for carotenoid synthesis lie together at the cara-carb chromosomal locus and are co-ordinately activated by blue light. a 12-kb dna stretch from wild-type m. xanthus has been sequenced that includes the entire cara-carb gene cluster. according to sequence analysis, the cluster contains 11 different genes. intergenic distances are very short or nil (implying translational coupling), giving further support to previous evidence indicating that most ...	1995	7588751
gliding movements in myxococcus xanthus.	prokaryotic gliding motility is described as the movement of a cell on a solid surface in the direction of the cell's long axis, but its mechanics are unknown. to investigate the basis of gliding, movements of individual myxococcus xanthus cells were monitored by employing a video microscopy method by which displacements as small as 0.03 micron could be detected and speeds as low as 1 micron/min could be resolved. single cells were observed to glide with speeds varying between 1 and 20 microns/m ...	1995	7592333
using a phase-locked mutant of myxococcus xanthus to study the role of phase variation in development.	the bacterium myxococcus xanthus undergoes a primitive developmental cycle in response to nutrient deprivation. the cells aggregate to form fruiting bodies in which a portion of the cells differentiate into environmentally resistant myxospores. during the growth portion of the m. xanthus life cycle, the organism also undergoes a phase variation, in which cells alternate between yellow and tan colony-forming variants. phase variation occurs in our laboratory strain (m102, a derivative of dk1622) ...	1995	7608083
two reca genes in myxococcus xanthus.	two reca genes, reca1 and reca2, in myxococcus xanthus were cloned by using the reca gene of escherichia coli, and their dna sequences were determined. on the basis of deduced amino acid sequences, reca1 and reca2 have 67.0% identity to each other and 60.5 and 60.9% identities to e. coli reca, respectively. expression of reca2 was detected in both vegetative and developmental cells by northern blot (rna) analysis, and a threefold induction was observed when cells were treated with nalidixic acid ...	1995	7608099
ectopic production of guanosine penta- and tetraphosphate can initiate early developmental gene expression in myxococcus xanthus.	amino acid or carbon limitation is sufficient to initiate fruiting body development in myxococcus xanthus. in both escherichia coli and m. xanthus the levels of guanosine 3'-di-5'-(tri)di-phosphate nucleotides [(p)ppgpp] rise transiently when cells are starved for amino acids or carbon. ectopic increase in the intracellular concentration of (p)ppgpp was achieved in m. xanthus by introducing a copy of the e. coli rela gene, whose product catalyzes pyrophosphate transfer from atp- to gtp-forming p ...	1995	7628697
germination of myxospores from the fruiting bodies of myxococcus xanthus.	germination of myxospores from fruiting bodies of myxococcus xanthus was examined under a light microscope as well as by analyzing the incorporation of [3h]uracil into the rna fraction. efficient germination was observed in 0.2% casitone containing 8 mm mgso4 and 1 mm cacl2 at 30 degrees c. under this condition, spherical myxospores were converted into rod-shaped vegetative cells within 5 to 6 h. the germination was severely inhibited in the presence of 1 mm phenylmethylsulfonyl fluoride, a prot ...	1995	7635813
an early a-signal-dependent gene in myxococcus xanthus has a sigma 54-like promoter.	a-signaling plays an essential role in the early stages of myxococcus xanthus fruiting body development. expression of the 452i gene, which is regulated at the level of rna accumulation, depends on starvation and on a-signaling. to identify the cis-acting regulatory elements which allow gene 4521 to respond to the nutritional and a-factor signals, the 4521 transcription start site was mapped. the region just upstream of the start site showed sequence similarity to the sigma 54 family of promoter ...	1995	7642489
identification of the minimum regulatory region of a myxococcus xanthus a-signal-dependent developmental gene.	developmental expression of the myxococcus xanthus gene 4521 requires extracellular a-signal. this signal is generated in response to nutrient limitation and functions in cell density sensing. to identify the upstream limit of the minimum region required in vivo for a-signal-dependent 4521 expression, a 5' deletion analysis of the 4521 regulatory region was performed. a new vector, phbk280, was designed to facilitate this analysis. this vector creates tandem copies of the 4521 gene in the m. xan ...	1995	7642490
the crystal structure of a human nucleoside diphosphate kinase, nm23-h2.	the 2.8 a resolution x-ray structure of nm23-h2 has been determined by molecular replacement using the structure of myxococcus xanthus nucleoside diphosphate (ndp) kinase. nm23-h2 is a human ndp kinase. the enzyme catalyses phosphoryl transfer, binds dna, and can activate the transcription of the c-myc oncogene in vitro. nm23 has also been reported to be a suppressor of metastasis in some types of tumours. whereas the m. xanthus ndp kinase is a tetramer, nm23-h2 is a hexamer. the fold of nm23-h2 ...	1995	7658474
methionine inhibits developmental aggregation of myxococcus xanthus by blocking the biosynthesis of s-adenosyl methionine.	previous studies showed that high concentrations of methionine (> 1 mm) inhibited aggregation and fruiting body formation in myxococcus xanthus (e. rosenberg, d. filer, d. zafriti, and s. h. kindler, j. bacteriol. 115: 29-34, 1973, and j. m. campos and d. r. zusman, proc. natl. acad. sci. usa 72:518-522, 1975). however, the mechanism for the inhibition was unclear. in this study, we found that high levels of methionine inhibited the biosynthesis of s-adenosylmethionine (sam) and that reduced int ...	1995	7665525
a tactile sensory system of myxococcus xanthus involves an extracellular nad(p)(+)-containing protein.	csga is a cell surface protein that plays an essential role in tactile responses during myxococcus xanthus fruiting body formation by producing the morphogenic c-signal. the primary amino acid sequence of csga exhibits homology with members of the short-chain alcohol dehydrogenase (scad) family and several lines of evidence suggest that nad(p)+ binding is essential for biological activity. first, the predicted csga secondary structure based on the 3 alpha/20 beta-hydroxysteroid dehydrogenase cry ...	1995	7498792
sterol uptake induced by an impairment of pyridoxal phosphate synthesis in saccharomyces cerevisiae: cloning and sequencing of the pdx3 gene encoding pyridoxine (pyridoxamine) phosphate oxidase.	exogenous sterols do not permeate wild-type saccharomyces cerevisiae in aerobic conditions. however, mutant strain fkerg7, affected in lanosterol synthase, is a sterol auxotroph which is able to grow aerobically in the presence of ergosterol. viability of this strain depends on the presence of an additional mutation, aux30, that leads to sterol permeability. cells bearing the aux30 mutation fail to grow in standard yeast nitrogen base medium containing pyridoxine but grow normally if pyridoxine ...	1995	7896706
the 'chea' and 'chey' domains of myxococcus xanthus frze function independently in vitro as an autokinase and a phosphate acceptor, respectively.	frze is a chemotaxis protein in myxococcus xanthus which has sequence homology to two different chemotaxis proteins of enteric bacteria, chea (autokinase) and chey (phosphate acceptor) [proc. natl. acad. sci. usa 87 (1990) 5898-5902]. it was also shown that a recombinant frze protein was autophosphorylated when incubated in the presence of atp and mn2+ [j. bacteriol. 172 (1990) 6661-6668]. in this study, we further investigated the biochemical properties of frze. two recombinant proteins were pr ...	1995	7821424
an endo-n-acetyl-beta-d-glucosaminidase, acting on the di-n-acetylchitobiosyl part of n-linked glycans, is secreted during sporulation of myxococcus xanthus.	after the demonstration that stigmatella aurantiaca dw4 secretes an endo-n-acetyl-beta-d-glucosaminidase (engase), acting on the di-n-acetylchitobiosyl part of n-linked glycans (s. bourgerie, y. karamanos, t. grard, and r. julien, j. bacteriol. 176:6170-6174, 1994), an engase activity having the same substrate specificity was also found to be secreted during vegetative growth of myxococcus xanthus dk1622. the activity decreased in mutants known to secrete less protein than the wild type (exc +/- ...	1995	7860600
cloning, expression, and characterization of the lon gene of erwinia amylovora: evidence for a heat shock response.	the gene encoding the lon protease of erwinia amylovora has been cloned by complementation of an escherichia coli lon mutant. analysis of the determined nucleotide sequence of the lon gene revealed extensive homology to the nucleotide sequences of cloned lon genes from e. coli, myxococcus xanthus, and bacillus brevis. the predicted amino acid sequence of the e. amylovora lon protease was 94, 59, and 54% identical to the predicted amino acid sequences of the lon proteases of e. coli, m. xanthus, ...	1995	7860603
identification of genes negatively regulated by fis: fis and rpos comodulate growth-phase-dependent gene expression in escherichia coli.	fis is a nucleoid-associated protein in escherichia coli that has been shown to regulate recombination, replication, and transcription reactions. it is expressed in a transient manner under batch culturing conditions such that high levels are present during early exponential phase and low levels are present during late exponential phase and stationary phase. we have screened a random collection of transposon-induced lac fusions for those which give decreased expression in the presence of fis. th ...	1995	7860604
nm23/nucleoside diphosphate kinase: toward a structural and biochemical understanding of its biological functions.	the nm23 gene, a putative metastasis suppressor gene, was originally identified by its reduced expression in highly metastatic k-1735 murine melanoma cell lines, as compared to related, low metastatic melanoma cell lines. transfection of nm23 cdna has been reported to suppress malignant progression in drosophila and mammalian cells. highly conserved homologues of nm23 have been found in organisms ranging from the prokaryote myxococcus xanthus to drosophila, where the gene is involved in normal d ...	1995	7702594
the myxococcus xanthus asga gene encodes a novel signal transduction protein required for multicellular development.	the myxococcus xanthus asga gene is one of three known genes necessary for the production of extracellular a-signal, a cell density signal required early in fruiting body development. we determined the dna sequence of asga. the deduced 385-amino-acid sequence of asga was found to contain two domains: one homologous to the receiver domain of response regulators and the other homologous to the transmitter domain of histidine protein kinases. a kanamycin resistance (kmr) gene was inserted at variou ...	1995	7721694
myxococcus xanthus, a gram-negative bacterium, contains a transmembrane protein serine/threonine kinase that blocks the secretion of beta-lactamase by phosphorylation.	a gene, pkn2, encoding a myxococcus xanthus protein with significant similarities to eukaryotic protein serine/threonine kinases, was cloned using the polymerase chain reaction. the open reading frame for the protein, beginning with a gug initiation codon, consists of 830 amino acids. the amino-terminal 279 residues show 37% identity to catalytic domain of pkn1, another protein serine/threonine kinase expressed during the development at the onset of sporulation. the catalytic domain of pkn2 cont ...	1995	7774814
the 1.9 a crystal structure of a nucleoside diphosphate kinase complex with adenosine 3',5'-cyclic monophosphate: evidence for competitive inhibition.	the x-ray structure of myxococcus xanthus nucleoside diphosphate (ndp) kinase complexed with adenosine 3',5'-cyclic monophosphate (camp) has been determined. the structure was solved by difference fourier analysis. the refined structure has a crystallographic r-factor of 0.17 at 1.9 a resolution. the phosphoryl group and ribose moiety make extensive polar interactions with the protein, whereas the base interacts only with two hydrophobic residues. the comparison with the structure of the enzyme ...	1995	7783219
genetic suppression and phenotypic masking of a myxococcus xanthus frzf- defect.	an insertion of transposon tn5-lac, omega 4519, generates a lacz fusion with a myxococcus xanthus promoter expressed during both vegetative growth and development. sequence analysis of the junction of omega 4519 with m. xanthus dna shows that the insertion is in frzf, a homologue of cher from salmonella typhimurium. when frzf- (or frzcd-) cells are starved for nutrients at modest densities, they aggregate to form a radial pattern and produce fewer than 1% of the wild-type complement of spores. a ...	1995	7783619
the pseudomonas aeruginosa pilk gene encodes a chemotactic methyltransferase (cher) homologue that is translationally regulated.	a new locus, designated pilk, located immediately adjacent to the previously described pseudomonas aeruginosa pilg-j gene cluster, has been identified. sequence analysis of a 1.3 kb region revealed the presence of a single open reading frame of 291 amino acid residues (m(r) 33,338) that contained significant homology to the chemotactic methyltransferase proteins of escherichia coli, bacillus subtilis and the gliding bacterium myxococcus xanthus. the 60 bp pilj-pilk intergenic region was devoid o ...	1995	7783642
the gene encoding the beta-1,4-endoglucanase (cela) from myxococcus xanthus: evidence for independent acquisition by horizontal transfer of binding and catalytic domains from actinomycetes.	the cela gene encoding a beta-1,4 endoglucanase (cela) from myxococcus xanthus has been cloned in escherichia coli and sequenced. the c-terminal region of cela displayed a high level of similarity with the catalytic domain of several egl belonging to the glycosyl hydrolases family 6 (cena from cellulomonas fimi, cela from microbispora bispora, e2 from thermonospora fusca, casa from streptomyces ksm9 and cela1 from streptomyces halstedii) and less similarity to the cellobiohydrolases of the fungi ...	1995	7789807
phylogenetic comparison of retron elements among the myxobacteria: evidence for vertical inheritance.	twenty-eight myxobacterial strains, representing members from all three subgroups, were screened for the presence of retron elements, which are novel prokaryotic retroelements encoding reverse transcriptase. the presence of retrons was determined by assaying strains for a small satellite dna produced by reverse transcription called multicopy, single-stranded dna (msdna). an msdna-producing retron appeared to be absent from only one of the strains surveyed. dna hybridization experiments revealed ...	1995	7798147
mlpa, a lipoprotein required for normal development of myxococcus xanthus.	the mlpa gene encoding a 236-residue polypeptide has been identified immediately downstream of the oar gene of myxococcus xanthus (m. martinez-canamero, j. munoz-dorado, e. farez-vidal, m. inouye, and s. inouye, j. bacteriol. 175:4756-4763, 1993). the amino-terminal 21 residues of mlpa encode a typical prokaryotic signal sequence with a putative lipoprotein cleavage site. when expressed in escherichia coli in the presence of [2-3h]glycerol, 3h-labeled mlpa had a molecular mass of 33 kda and was ...	1995	8522522
stimulation of endothelial cell growth by myxalin.		1995	8528508
a missense mutation in rpod results in an a-signalling defect in myxococcus xanthus.	the myxococcus xanthus asg genes (asga, asgb, and asgc) are necessary for production of extracellular a-signal, which is thought to function as a cell-density signal. previous analyses of the asga and asgb genes suggest that they perform regulatory functions. in this work, we localized asgc to a region that contains genes homologous to rpsu, dnag, and rpod of the escherichia coli macromolecular synthesis (mms) operon. surprisingly, asgc767 was found to be a mutant allele of rpod, the gene encodi ...	1995	8825098
the social behavior of myxobacteria.	myxobacteria are social microorganisms that undergo a spectacular cell cycle. under starvation conditions, cells aggregate to certain points originating macroscopic fruiting bodies, inside which cells differentiate into myxospores. to accomplish this developmental cycle, cells must communicate. the signals that cells exchange during development as well as the signal transduction systems used by myxobacteria have been intensively studied during the last years. a family of eukaryotic-like protein ...	1995	8588838
monoclonal antibodies against antigens exposed on the surface of vegetative forms and spores of myxococcus virescens.	twelve monoclonal antibodies (mabs) directed against cell-surface antigens of myxococcus virescens cells were developed and partially characterized. all of them recognized multiple, diffuse proteic bands in western blot and four were also reactive to living bacteria, as assessed by flow cytometry. the four latter mabs recognized antigens common to a number of vegetative forms and spores. the selective expression of proteins recognized by mabs on the microorganisms and the possible applications o ...	1995	8590393
genetic and functional evidence that type iv pili are required for social gliding motility in myxococcus xanthus.	the social gliding behaviour of myxococcus xanthus has previously been associated with the presence of polar pili. a tn5 transposon insertion was isolated which introduces a defect in social gliding and is genetically linked to a known sgl locus; this insertion was found also to cause a piliation defect. a 2.7 kb section of dna was isolated from either side of this transposon and sequenced, revealing three genes which encode amino acid sequences with substantial similarity to components of the t ...	1995	8748037
genetics of gliding motility and development in myxococcus xanthus.	successful development in multicellular eukaryotes requires cell-cell communication and the coordinated spatial and temporal movements of cells. the complex array of networks required to bring eukaryotic development to fruition can be modeled by the development of the simpler prokaryote myxococcus xanthus. as part of its life cycle, m. xanthus forms multicellular fruiting bodies containing differentiated cells. analysis of the genes essential for m. xanthus development is possible because strain ...	1995	8572884
starvation yields a drastic decrease in outer-membrane permeability to a periplasmic foreign protein in myxococcus xanthus.	a recombinant myxococcus xanthus strain was constructed that constitutively produces two proteins from escherichia coli, the cytoplasmic beta-galactosidase and the periplasmic ph 2.5 acid phosphatase (appa protein). we have previously shown that during vegetative growth, appa protein is partly accumulated in the periplasm of m. xanthus and partly released into the medium. we demonstrate here that during starvation-induced development, release of periplasmic appa protein to the medium did not occ ...	1995	8574405
suppression of a signaling defect during myxococcus xanthus development.	the csga gene encodes an extracellular protein that is essential for cell-cell communication (c-signaling) during fruiting body development of myxococcus xanthus. two transposon insertions in the socabc operon, soc-560 and socc559, restore development to csga null mutants. mixing soc-560 csga cells or socc559 csga cells with csga cells at a ratio of 1:1 stimulated the development of csga cells, suggesting that soc mutations allow cells to produce the c-signal or a similar molecule via a csga-ind ...	1996	8576071
secretion kinetics of endo-n-acetyl-beta-d-glucosaminidase during vegetative growth of myxococcus xanthus.	it was recently demonstrated that endo-n-acetyl-beta-d-glucosaminidases (engase) acting on n-glycosylproteins are produced by myxobacteria. in this study, it was shown that the secretion of engase during vegetative growth of myxococcus xanthus was cell-density-dependent. the activity produced per cell increased up to 6 x 10(8) cells/ml and stabilized thereafter (maximum level). two of the developmental mutants used in this study (bsga and csga) were locked for engase secretion into the maximum l ...	1996	8763609
integration of bacteriophage mx8 into the myxococcus xanthus chromosome causes a structural alteration at the c-terminal region of the intp protein.	mx8 is a generalized transducing phage that infects myxococcus xanthus cells. this phage is lysogenized in m. xanthus cells by the integration of its dna into the host chromosome through site-specific recombination. here, we characterize the mechanism of mx8 integration into the m. xanthus chromosome. the mx8 attachment site, attp, the m. xanthus chromosome attachment site, attb, and two phage-host junctions, attl and attr, were cloned and sequenced. sequence alignments of attp, attb, attl, and ...	1996	8763924
tyrosine phosphorylation in myxococcus xanthus, a multicellular prokaryote.	tyrosine phosphorylation is an extremely rare event in prokaryotes, occurring almost exclusively in multicellular eukaryotes. we have identified, for the first time, by the use of antiphosphotyrosine monoclonal antibody and western blot (immunoblot) analysis, two tyrosine-phosphorylated membrane proteins in the multicellular prokaryote myxococcus xanthus. the pattern of tyrosine phosphorylation was shown to change during development, indicating a possible role for this regulatory modification du ...	1996	8763935
light-induced carotenogenesis in myxococcus xanthus: light-dependent membrane sequestration of ecf sigma factor carq by anti-sigma factor carr.	light-induced carotenogenesis in myxococcus xanthus is under the control of the carqrs operon. carq, a proposed extracytoplasmic (ecf) rna polymerase sigma factor, is required for expression of the operon and the carc gene that encodes phytoene dehydrogenase. carr, an inner membrane protein in escherichia coli, is essential for carqrs promoter inactivation in the dark. cars is required for the light-dependent expression of the promoter of the carb gene cluster that encodes the rest of the struct ...	1996	8821946
propagation of traveling waves in excitable media.		1996	8824584
markerless deletions of pil genes in myxococcus xanthus generated by counterselection with the bacillus subtilis sacb gene.	in-frame deletions of pila and pils were constructed in myxococcus xanthus with a plasmid integration-excision strategy facilitated by sacb. sacb conferred sucrose sensitivity upon its m. xanthus host only when it lay in the same orientation as adjacent m. xanthus genes. gene orientation also affected the efficiency of sucrose counterselection in the sucrose-sensitive strains. the deltapila mutant lacked pili and social motility, while the deltapils mutant showed no defect in either phenotype.	1996	8824635
intercellular c-signaling in myxococcus xanthus involves a branched signal transduction pathway.	c-factor, the product of the csga gene, is a cell-surface associated short-range intercellular signaling protein in myxococcus xanthus. c-factor is required for at least four responses during starvation-induced fruiting body morphogenesis: rippling, aggregation, sporulation, and full expression of the csga gene, all of which fail in a csga mutant. to analyze the c-factor signaling pathway, eight tn5 lac insertion mutants that began but failed to complete fruiting body aggregation were characteri ...	1996	8598300
c factor, a cell-surface-associated intercellular signaling protein, stimulates the cytoplasmic frz signal transduction system in myxococcus xanthus.	c factor, an intercellular signaling protein, is required for aggregation and sporulation of the social bacterium, myxococcus xanthus. we report that c factor, which normally is associated with the cell surface, provides input to the frz signal transduction cascade. elements of this cascade have sequence homology to bacterial chemotaxis systems and are known to control the frequency of gliding reversal. exposure of developing cells of a c-factor-less mutant (csga) to purified c factor increases ...	1996	8610100
protoporphyrinogen oxidase of myxococcus xanthus. expression, purification, and characterization of the cloned enzyme.	protoporphyrinogen oxidase (ec 1.3.3.4) catalyzes the six electron oxidation of protoporphyrinogen ix to protoporphyrin ix. the enzyme from the bacterium myxococcus xanthus has been cloned, expressed, purified, and characterized. the protein has been expressed in escherichia coli using a tac promoter-driven expression plasmid and purified to apparent homogeneity in a rapid procedure that yields approximately 10 mg of purified protein per liter of culture. based upon the deduced amino acid sequen ...	1996	8621504
the myxococcus xanthus rfbabc operon encodes an atp-binding cassette transporter homolog required for o-antigen biosynthesis and multicellular development.	a wild-type sasa locus is critical for myxococcus xanthus multicellular development. mutations in the sasa locus cause defective fruiting body formation, reduce sporulation, and restore developmental expression of the early a-signal-dependent gene 4521 in the absence of a signal. the wild-type sasa locus has been located on a 14-kb cloned fragment of the m. xanthus chromosome. the nucleotide sequence of a 7-kb region containing the complete sasa locus was determined. three open reading frames en ...	1996	8626291
characterization of the regulatory region of a cell interaction-dependent gene in myxococcus xanthus.	omega 4403 is the site of a tn5 lac insertion in the myxococcus xanthus genome that fuses lacz expression to a developmentally regulated promoter. cell-cell interactions that occur during development, including c-signaling, are required for expression of tn5 lac omega 4403. we have cloned dna upstream of the omega 4403 insertion site, localized the promoter, and identified a potential open reading frame. from the deduced amino acid sequence, the gene disrupted by tn5 lac omega 4403 appears to en ...	1996	8626320
photolyase of myxococcus xanthus, a gram-negative eubacterium, is more similar to photolyases found in archaea and "higher" eukaryotes than to photolyases of other eubacteria.	we report the identification of the gene encoding a dna photolyase (phra) from the gram-negative eubacterium myxococcus xanthus. the deduced amino acid sequence of m. xanthus photolyase indicates that the protein contains 401 amino acids (mr 45,071). by comparison of the amino acid and dna sequences with those of other known photolyases, it has been found that it is more similar to the deduced amino acid sequences of the photolyases of "higher" eukaryotes than to the photolyases of other eubacte ...	1996	8626418
cell density regulates cellular reversal frequency in myxococcus xanthus.	myxococcus xanthus is a gram-negative bacterium that aggregates to form fruiting bodies when nutrients are limiting. previous studies showed that the frz mutants that are defective in chemotaxis exhibited irregular and infrequent patterns of cellular reversal. in contrast, wild-type cells, when examined individually, reverse relatively frequently, about once every 6 min. it is not known how the change of reversal frequency effects cellular aggregation during fruiting body formation in m. xanthus ...	1996	8633030
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
gliding motility in slide cultures of myxococcus xanthus in stable and steep chemical gradients.	a method was devised to construct stable and steep chemical gradients in slide cultures to study the movements of gliding cells. the movement of myxococcus xanthus individual cells and small swarms was studied in these gradients. there was no response to gradients of casitone and yeast extract that were previously reported to stimulate a positive chemotactic response with m. xanthus.	1996	8655544
molecular cloning and characterization of ddcad-1, a ca2+-dependent cell-cell adhesion molecule, in dictyostelium discoideum.	dictyostelium discoideum expresses edta-sensitive cell-cell adhesion sites soon after the initiation of development, and a ca2+-binding protein of mr 24,000 (designated ddcad-1) has been implicated in this type of adhesiveness. we have previously purified ddcad-1 to homogeneity and characterized its cell binding activity (brar, s. k., and siu, c.-h. (1993) j. biol. chem. 268, 24902-24909). in this report, we describe the cloning of ddcad-1 cdnas. dna sequencing revealed a single open reading fra ...	1996	8663243
a r59w mutation in human protoporphyrinogen oxidase results in decreased enzyme activity and is prevalent in south africans with variegate porphyria.	variegate porphyria (vp), a low-penetrant autosomal dominant inherited disorder of haem metabolism, is characterised by photosensitivity (fig. 1) and a propensity to develop acute neuropsychiatric attacks with abdominal pain, vomiting, constipation, tachycardia, hypertension, psychiatric symptoms and, in the worst cases, quadriplegia. acute attacks, often precipitated by inappropriate drug therapy, are potentially fatal. while earlier workers thought the distal haem biosynthetic enzyme ferrochel ...	1996	8673113
a myxococcus xanthus cell density-sensing system required for multicellular development.	progression through early myxococcus xanthus multicellular fruiting body development requires the generation of and response to extracellular a signal. extracellular a signal is a specific set of amino acids at an extracellular concentration greater than 10 mum. it functions as a cell density signal during starvation that allows the cells to sense that a minimal cell density has been reached and development can proceed. the generation of extracellular a signal requires the products of three asg ...	1996	8674994
sequences of the salmonella typhimurium mgla and mglc genes.	the nucleotide sequences of the mgla and mglc genes of salmonella typhimurium (st) lt2 have been determined. the deduced amino acid (aa) sequences of mgla and mglc are 506 and 302 aa long with predicted molecular masses of 56,484 and 31,551 da, respectively. the aa sequences of st mgla and mglc are homologous to the corresponding mgl proteins of escherichia coli, haemophilus influenzae, treponema pallidum and mycoplasma genitalium. the order of the st mgl operon is mglbac.	1996	8675022
use of pcr to isolate genes encoding sigma54-dependent activators from diverse bacteria.	degenerate pcr probes were used to amplify gene fragments encoding the catalytic domain of sigma54-dependent transcription activators. the procedure should be widely applicable, as it recovered both known and novel gene fragments: 5 from rhizobium meliloti, 13 from myxococcus xanthus, and 3 from bacillus subtilis. no fragments were obtained from synechococcus sp. strain pcc 7002 or saccharomyces cerevisiae.	1996	8682806
high mobility group i(y)-like dna-binding domains on a bacterial transcription factor.	the bacterium myxococcus xanthus responds to blue light by producing carotenoids. it also responds to starvation conditions by developing fruiting bodies, where the cells differentiate into myxospores. each response entails the transcriptional activation of a separate set of genes. however, a single gene, card, is required for the activation of both light- and starvation-inducible genes. gene card has now been sequenced. its predicted amino acid sequence includes four repeats of a dna-binding do ...	1996	8692912
reciprocal regulation of the differentiation of myxococcus xanthus by pkn5 and pkn6, eukaryotic-like ser/thr protein kinases.	myxococcus xanthus contains a large family of genes encoding eukaryotic-like serine/threonine kinases. among them, two genes, pkn5 and pkn6, are divergently located on the chromosome and share a 46 bp promoter region between their transcription initiation sites, as determined by rna protection. pkn5, consisting of 380 amino acid residues, is a soluble protein in the cytoplasm, while pkn6, consisting of 710 amino acid residues, is a transmembrane protein. its membrane topology was determined usin ...	1996	8733241
identification and characterization of frzz, a novel response regulator necessary for swarming and fruiting-body formation in myxococcus xanthus.	the frz genes of myxococcus xanthus constitute a signal-transduction pathway that processes chemotactic information in a manner analogous to that found in enteric bacteria. ultimately, these genes regulate the frequency of individual cell reversal. we report here the identification of a novel component of this signal-transduction pathway, designated frzz, which was discovered as an open reading frame located 5' to the frz operon but transcribed in the opposite orientation. the translational star ...	1996	8736543
defect in export and synthesis of the periplasmic galactose receptor mglb in dnak mutants of escherichia coli, and decreased stability of the mglb mrna.	the high-affinity galactose permease, which comprises the periplasmic galactose receptor mglb, the membrane translocator mglc and the membrane-associated atpase mgla, displayed a reduced activity in a dnak temperature-sensitive mutant of escherichia coli. this reduced transport activity correlated with a reduction in the quantity of mglb. at 42 degrees c, an accumulation of pre-mglb in the dnak temperature-sensitive mutant reflected a defect in mglb export. in addition, an accumulation of pre-mg ...	1996	8828228
sequence and analysis of a 33 kb fragment from the right arm of chromosome xv of the yeast saccharomyces cerevisiae.	we have determined the nucleotide sequence of a cosmid (peoa423) from chromosome xv of saccharomyces cerevisiae. analysis of the 33,173 bp sequence reveals the presence of 20 putative open reading frames (orfs). five of them correspond to previously known genes (mgm1, ste4, cdc44, ste13, rpb8). the previously published nucleotide sequences are in perfect agreement with our sequence except for ste4 and mgm1. in the latter case, 59 amino acids were truncated from the published protein at its n-ter ...	1996	8840505
bacterial signalling involving eukaryotic-type protein kinases.	protein ser, thr and tyr kinases play essential roles in signal transduction in organisms ranging from yeast to mammals, where they regulate a variety of cellular activities. during the last few years, a number of genes that encode eukaryotic-type protein kinases have also been identified in four different bacterial species, suggesting that such enzymes are also widespread in prokaryotes. although many of them have yet to be fully characterized, several studies indicate that eukaryotic-type prot ...	1996	8861199
a mgl-like operon in treponema pallidum, the syphilis spirochete.	a 38-kda lipoprotein of treponema pallidum subsp. pallidum (t. pallidum), the syphilis spirochete, previously was identified as a putative homolog of e. coli mglb [becker et al. (1994) infect. immun. 62, 1381-1391]. in the present study, genome walking in regions adjacent to the t. pallidum 38-kda lipoprotein gene has identified three contiguous genes (tp-mglb [formerly tpp38], tp-mgla, and tp-mglc) which appear to comprise a mgl-like operon in t. pallidum. a prominent transcript corresponding t ...	1996	8921855
the myxococcus xanthus developmentally expressed asgb-dependent genes can be targets of the a signal-generating or a signal-responding pathway.	functional myxococcus xanthus a signal-generating and a signal-responding pathways are required for the progression through early multicellular development. to identify genes responsive to these pathways, the expression of eight early developmental genes was analyzed. this examination identified one gene as a target of the a signal-generating pathway and four genes as targets of the a signal-responding pathway.	1996	8932321
effects of overexpression of pkn2, a transmembrane protein serine/threonine kinase, on development of myxococcus xanthus.	pkn2 is a putative transmembrane protein serine/threonine kinase required for normal development of myxococcus xanthus. the effect of pkn2 overexpression on development of m. xanthus was examined by expressing pkn2 under the control of a kanamycin promoter. pkn2 was clearly detected by western blot (immunoblot) analysis in the overexpression strain (the pkm/pkn2 strain) but could not be detected in the wild-type strain. overexpressed pkn2 was located almost exclusively in the membrane fraction, ...	1996	8932326
two multifunctional peptide synthetases and an o-methyltransferase are involved in the biosynthesis of the dna-binding antibiotic and antitumour agent saframycin mx1 from myxococcus xanthus.	saframycin mx1 is a dna-binding antibiotic and antitumour agent produced by myxococcus xanthus. it is a heterocyclic quinone, thought to be synthesized via the linear peptide intermediate alaglytyrtyr. analysis of 14.1 kb dna sequence involved in saframycin production revealed genes for two large multifunctional peptide synthetases of 1770 and 2605 amino acids, respectively, and a putative o-methyltransferase of 220 amino acids. the three orfs read in the same direction and are separated by shor ...	1996	8936303
frua, a putative transcription factor essential for the development of myxococcus xanthus.	a new developmental gene, frua, of myxococcus xanthus was cloned using a one-step cloning vector, tnv. dna sequencing of the wild-type allele of the frua gene indicated that the frua gene encodes a protein of 229 amino acid residues with a calculated molecular weight of 24672. the deduced amino acid sequence of frua protein showed similarity to those of many bacterial regulatory proteins carrying a dna-binding helix-turn-helix motif. the transcription-initiation site of the frua gene was determi ...	1996	8951822
identification and sequences of the treponema pallidum mgla and mglc genes.	treponema pallidum, the agent of syphilis, cannot be continuously cultivated in vitro. to identify treponemal genes encoding exported proteins, we performed tnphoa mutagenesis of a t. pallidum genomic dna library in escherichia coli. clone 6d2 was chosen for further study based on partial nucleotide sequence obtained from p6d2 containing a tnphoa insertion. a complete open reading frame (orf1) and a truncated orf (orf2) were identified in the treponemal dna of p6d2. orf1 encodes a hydrophobic pr ...	1996	8988365
positive-negative kg cassettes for construction of multi-gene deletions using a single drug marker.	positive-negative kg cassettes were developed in order to create a number of independent deletion mutations on the bacterial chromosome using a single drug marker. these cassettes consist of a kanamycin-resistant (kmr) gene for positive screening and a galactokinase gene (galk) for negative screening. both genes are in an operon driven by the native kmr promoter and are flanked by identical fragments of yeast chromosomal dna approximately one kb in size. an internal region of a cloned target gen ...	1996	8996101
behavioral analysis of single cells of myxococcus xanthus in response to prey cells of escherichia coli.	myxococcus xanthus cells move over surfaces by gliding motility. the frz signal transduction system is used to control the reversal frequency, and thus the overall direction of movement of m. xanthus cells. we analyzed the behavior of wild-type and frz mutant cells in response to prey bacteria (escherichia coli). wild-type cells of m. xanthus did not respond to microcolonies of e. coli until they made physical contact. cells which penetrated a colony remained in the colony until all of the prey ...	1996	8998990
purification and in vitro phosphorylation of myxococcus xanthus asga protein.	the deduced amino acid sequence of the myxococcus xanthus asga protein contains an n-terminal domain that is homologous to the receiver of response regulators and a c-terminal domain that is homologous to the transmitter of histidine protein kinases. we overexpressed affinity-tagged asga in escherichia coli, purified the recombinant protein, and showed that asga has autokinase activity in vitro. the results of chemical-stability assays suggest that asga is phosphorylated on a histidine and provi ...	1996	8550431
mutants of myxococcus xanthus dsp defective in fibril binding.	the dsp mutant of myxococcus xanthus lacks extracellular fibrils and as a result is unable to undergo cohesion, group motility, or development (j. w. arnold and l. j. shimkets, j. bacteriol. 170:5765-5770, 1983; j. w. arnold and l. j. shimkets, j. bacteriol. 170:5771-5777, 1983; r. m. behmlander and m. dworkin, j. bacteriol. 173:7810-7821, 1991; l. j. shimkets, j. bacteriol. 166:837-841, 1986; l. j. shimkets, j. bacteriol. 166:842-848, 1986). however, cohesion and development can be phenotypical ...	1996	8550502
why and how bacteria communicate.		1997	9000763
biochemical characterization of pkn2, a protein ser/thr kinase from myxococcus xanthus, a gram-negative developmental bacterium.	pkn2, a protein ser/thr kinase, from the developmental bacterium myxococcus xanthus was expressed under a t7 promoter in escherichia coli and purified. purified pkn2 retained the autophosphorylation activity with the km value of 177 microm for atp and 73 nmol/min/mg for vmax. the optimum ph and temperature were determined to be 7.5 and 35 degrees c, respectively. the autophosphorylation activity was inhibited by staurosporine with the ic50 value of 400 nm while h-7 and genistein had little effec ...	1997	9001395
the myxococcus xanthus pilt locus is required for social gliding motility although pili are still produced.	social gliding motility in myxococcus xanthus depends on the presence of type iv pili. to begin to examine the role of pili in social motility, 17 mutants were identified which had lost social motility, but still expressed pili. four of these mutants carry point mutations which mapped to a locus upstream of the recently identified pils, pilr, and pila genes. sequencing of this locus revealed a gene with homology to pilt from pseudomonas aeruginosa. sequencing of the four point mutations revealed ...	1997	9004225
characterization of csga, a new member of the forespore-expressed sigmag-regulon from bacillus subtilis.	a new locus, csga, has been identified in a search for developmental genes transcribed by e sigmag in bacillus subtilis. csga has the potential to encode three small proteins, csgaa, csgab and csgac. the latter two would be encoded by overlapping orfs. csga is expressed in the spore chamber of the differentiating cell and is under the control of sigmag and the transcriptional regulatory protein spovt. mutation of csga did not affect spore formation but produced a subtle defect in the ability of ...	1997	9016963
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
adp-ribosylation by the extracellular fibrils of myxococcus xanthus.	the isolated, extracellular fibrils of the myxobacterium, myxococcus xanthus, are capable of carrying out adp-ribosylation. the substrate for the adp-ribosylation is reactive with monoclonal antibody 2105, which has been shown to be directed specifically against the integral fibril proteins. the extracellular fibrils thus contain both the adp-ribosyl transferase and the substrate for the ribosylation. this process may play a role in the contact-mediated cell-cell interactions that are an importa ...	1997	9044257
pkn9, a ser/thr protein kinase involved in the development of myxococcus xanthus.	the myxococcus xanthus gene, pkn9, encodes a protein that contains significant homology with eukaryotic ser/thr protein kinases. the pkn9 gene was singled out of a previously identified family of kinase genes by amplification techniques that displayed differences in kinase gene expression during selected periods of the m. xanthus life cycle. pkn9 was constitutively expressed during vegetative growth and upregulated during the aggregation stage of early development. it consists of 589 amino acids ...	1997	9044280
sigma54, a vital protein for myxococcus xanthus.	the rpon gene encoding the transcription factor sigma54 in myxococcus xanthus has been cloned using a heterologous rpon probe. the sequence of the cross-hybridizing dna confirmed the existence of an orf 1518 bp long that encodes a well conserved member of the sigma54 family of sigma factors. low- as well as high-stringency hybridizations detected only a single rpon gene in the m. xanthus chromosome. in other bacteria, sigma54 is an alternative sigma, and null mutants are viable. however, all att ...	1997	9050890
a gene involved in both protein secretion during growth and starvation-induced development encodes a subunit of the nadh:ubiquinone oxidoreductase in myxococcus xanthus.	the secretion of numerous proteins during vegetative growth of myxococcus xanthus, and the multicellular development cycle induced upon starvation of these bacteria, are partially interrelated in so far as mutants impaired in extracellular protein production are unable to undergo development. we have cloned and sequenced a gene in which a tn5 insertion leads to a decrease in the production of most, if not all, extracellular proteins, and prevents development and sporulation. the deduced protein ...	1997	9076740
identification and characterization of myxococcus xanthus mutants deficient in calcofluor white binding.	calcofluor white is a fluorescent dye that binds to glycans and can be used to detect extracellular polysaccharide in myxococcus xanthus and many other bacteria. we observed that an esg mutant showed less binding to calcofluor white than wild-type cells. unlike s-motility mutants that share this phenotypic characteristic, the esg mutant exhibited s motility. this led us to identify a collection of nine new transposon insertion mutants, designated cds (for calcofluor white binding deficient and s ...	1997	9139901
starvation-independent sporulation in myxococcus xanthus involves the pathway for beta-lactamase induction and provides a mechanism for competitive cell survival.	myxococcus xanthus is a gram-negative, soil-dwelling bacterium with a complex life cycle which includes fruiting body formation and sporulation in response to starvation. this developmental process is slow, requiring a minimum of 24-48 h, and requires cells to be at high cell density on a solid surface. it is known that, in the absence of starvation, vegetatively growing cell suspensions can form 'glycerol spores' when exposed to high levels of glycerol, usually 0.5 m. the cells differentiate fr ...	1997	9194710