Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| effect of cellular filamentation on adventurous and social gliding motility of myxococcus xanthus. | filamentous bacterial cells often provide biological information that is not readily evident in normal-size cells. in this study, the effect of cellular filamentation on gliding motility of myxococcus xanthus, a gram-negative social bacterium, was investigated. elongation of the cell body had different effects on adventurous and social motility of m. xanthus. the rate of a-motility was insensitive to cell-body elongation whereas the rate of s-motility was reduced dramatically as the cell body go ... | 1999 | 10611358 |
| sequences and evolutionary analyses of eukaryotic-type protein kinases from streptomyces coelicolor a3(2). | four eukaryotic-type protein serine/threonine kinases from streptomyces coelicolor a3(2) were cloned and sequenced. to explore evolutionary relationships between these and other protein kinases, the distribution of protein serine/threonine kinase genes in prokaryotes was examined with the tfasta program. genes of this type were detected in only a few species of prokaryotes and their distribution was uneven; streptomyces, mycobacterium, synechocystis and myxococcus each contained more than three ... | 1999 | 10627033 |
| the myxococcus xanthus pilq (sgla) gene encodes a secretin homolog required for type iv pilus biogenesis, social motility, and development. | the myxococcus xanthus sgla1 spontaneous mutation was originally isolated because it allowed dispersed cell growth in liquid yet retained the ability to form fruiting bodies. consequently, most of today's laboratory strains either contain the sgla1 mutation or were derived from strains that carry it. subsequent work showed that sgla was a gene for social gliding motility, a process which is mediated by type iv pili. here sgla is shown to map to the major pil cluster and to encode a 901-amino-aci ... | 1999 | 9864308 |
| disruption of alda influences the developmental process in myxococcus xanthus. | previously, we identified a gene (alda) from myxococcus xanthus, which we suggested encoded the enzyme alanine dehydrogenase on the basis of similarity to known ald protein sequences (m. j. ward, h. lew, a. treuner-lange, and d. r. zusman, j. bacteriol. 180:5668-5675, 1998). in this study, we have confirmed that alda does encode a functional alanine dehydrogenase, since it catalyzes the reversible conversion of alanine to pyruvate and ammonia. whereas an alda gene disruption mutation did not sig ... | 2000 | 10629210 |
| the stringent response in myxococcus xanthus is regulated by soce and the csga c-signaling protein. | myxococcus xanthus fruiting body development is induced by amino acid limitation. the decision to grow or develop is established by the rela-dependent stringent response and a-signaling. we identified two new members of this regulatory hierarchy, soce and the c-signaling gene csga. soce depletion arrests growth and induces sporulation under conditions that normally favor growth as well as curtailing dna and stable rna synthesis, inhibiting cell elongation, and inducing accumulations of the strin ... | 2000 | 10691740 |
| the asge locus is required for cell-cell signalling during myxococcus xanthus development. | in response to starvation, myxococcus xanthus undergoes a multicellular developmental process that produces a dome-shaped fruiting body structure filled with differentiated cells called myxospores. two insertion mutants that block the final stages of fruiting body morphogenesis and reduce sporulation efficiency were isolated and characterized. dna sequence analysis revealed that the chromosomal insertions are located in open reading frames orf2 and asge, which are separated by 68 bp. the sporula ... | 2000 | 10692158 |
| evolution of arginine biosynthesis in the bacterial domain: novel gene-enzyme relationships from psychrophilic moritella strains (vibrionaceae) and evolutionary significance of n-alpha-acetyl ornithinase. | in the arginine biosynthetic pathway of the vast majority of prokaryotes, the formation of ornithine is catalyzed by an enzyme transferring the acetyl group of n-alpha-acetylornithine to glutamate (ornithine acetyltransferase [oatase]) (argj encoded). only two exceptions had been reported-the enterobacteriaceae and myxococcus xanthus (members of the gamma and delta groups of the class proteobacteria, respectively)-in which ornithine is produced from n-alpha-acetylornithine by a deacylase, acetyl ... | 2000 | 10692366 |
| a sigma(54) activator protein necessary for spore differentiation within the fruiting body of myxococcus xanthus. | insertion of an internal dna fragment into the act1 gene, which encodes one of several sigma(54)-activator proteins in myxococcus xanthus, produced a mutant defective in fruiting body development. while fruiting-body aggregation appears normal in the mutant, it fails to sporulate (<10(-6) the wild-type number of viable spores). the a and c intercellular signals, which are required for sporulation, are produced by the mutant. but, while it produces a-factor at levels as high as that of the wild t ... | 2000 | 10762243 |
| bacterial cheaters. | 2000 | 10766222 | |
| developmental cheating in the social bacterium myxococcus xanthus. | cheating is a potential problem in any social system that depends on cooperation and in which actions that benefit a group are costly to individuals that perform them. genetic mutants that fail to perform a group-beneficial function but that reap the benefits of belonging to the group should have a within-group selective advantage, provided that the mutants are not too common. here we show that social cheating exists even among prokaryotes. the bacterium myxococcus xanthus exhibits several socia ... | 2000 | 10766241 |
| effect of culture conditions on the formation of struvite by myxococcus xanthus. | the amount of struvite (mgnh4po4 x 6h2o) produced by myxococcus xanthus as well as the culture parameter values (ph, total phosphorus, total kjeldahl nitrogen) were dependent on the culture medium used. struvite formation started during the exponential phase and the maximum concentration was observed at the beginning of stationary growth phase. the addition of each medium component to the liquid culture influenced the amount of crystal produced. this amount did not depend on the ph increase duri ... | 2000 | 10789967 |
| purification and characterization of a novel lectin from a freshwater cyanobacterium, oscillatoria agardhii. | in the survey of 14 species of laboratory-cultured cyanobacteria for hemagglutinins, we newly detected the activity in two species, oscillatoria agardhii, strain nies-204, and phormidium foveolarum, strain nies-503. from the extract of o. agardhii, which showed the highest activity with trypsin-treated erythrocytes of rabbit, a lectin was purified to homogeneity by the combination of precipitation with (nh4)2so4, gel filtration, hydrophobic chromatography and reverse phase chromatography. the pu ... | 2000 | 10817903 |
| aglu, a protein required for gliding motility and spore maturation of myxococcus xanthus, is related to wd-repeat proteins. | the aglu gene of myxococcus xanthus encodes a protein similar to het-e1 (vegetative incompatibility) from podospora anserina, acylaminoacyl-peptidase from bacillus subtilis, and tolb from escherichia coli. these proteins all have evenly spaced spdg repeats that are characteristic of a larger motif called the wd-repeat. the wd-repeat is predicted to form a beta-propeller structure that mediates the assembly of heteromeric protein complexes. aglu has a consensus lipoprotein attachment motif that i ... | 2000 | 10844655 |
| a common step for changing cell shape in fruiting body and starvation-independent sporulation of myxococcus xanthus. | myxococcus xanthus can sporulate in either of two ways: at the end of the program of fruiting body development or after exposure of growing cells to certain reagents such as concentrated glycerol. fruiting body sporulation requires starvation, while glycerol sporulation requires rapid growth, and since the two types of spores are structurally somewhat different, it has generally been assumed that the two processes are different. however, a tn5 lac insertion mutation, omega7536, has been isolated ... | 2000 | 10852889 |
| developmental cheating and the evolutionary biology of dictyostelium and myxococcus. | 2000 | 10878115 | |
| fructose utilization and pathogenicity of spiroplasma citri: characterization of the fructose operon. | transposon tn4001 mutagenesis of spiroplasma citri wild-type (wt) strain gii-3 led to the isolation and characterization of non-phytopathogenic mutant gmt 553. in this mutant, transposon tn4001 is inserted within the first gene of the fructose operon. this operon comprises three genes. the first gene (frur) codes for a putative transcriptional regulator protein belonging to the deoxyribonucleoside repressor (deor) family. sequence similarities and functional complementation of mutant gmt 553 wit ... | 2000 | 10903438 |
| identification and characterization of genes required for early myxococcus xanthus developmental gene expression. | starvation and cell density regulate the developmental expression of myxococcus xanthus gene 4521. three classes of mutants allow expression of this developmental gene during growth on nutrient agar, such that colonies of strains containing a tn5 lac omega4521 fusion are lac(+). one class of these mutants inactivates sasn, a negative regulator of 4521 expression; another class activates sass, a sensor kinase-positive regulator of 4521 expression; and a third class blocks lipopolysaccharide (lps) ... | 2000 | 10913090 |
| spatial control of cell differentiation in myxococcus xanthus. | myxococcus xanthus develops species-specific multicellular fruiting bodies. starting from a uniform mat of cells, some cells enter into nascent fruiting body aggregates, whereas other cells remain outside. the cells within the fruiting body differentiate from rods into spherical, heat-resistant spores, whereas the cells outside the aggregates, called peripheral cells, remain rod-shaped. early developmentally regulated genes are expressed in peripheral cells as well as by cells in the fruiting bo ... | 2000 | 10922065 |
| the myxococcus xanthus soce and csga genes are regulated by the stringent response. | disruption of the myxococcus xanthus soce gene bypasses the requirement for the cell contact-dependent c-signalling system mediated by csga and restores fruiting body morphogenesis and spore differentiation. the soce gene has been identified by genetic complementation, cloned and sequenced. soce is highly basic, unique and is predicted to be a soluble protein with a molecular size of 53. 6 kda. the soce and csga genes have opposite transcription patterns during the m. xanthus life cycle. soce ex ... | 2000 | 10972801 |
| fructose operon mutants of spiroplasma citri. | fructose-negative mutants of spiroplasma citri wild-type strain gii-3 were selected by two methods. the first method is based on the selection of spontaneous xylitol-resistant mutants, xylitol being a toxic fructose analogue. five such mutants were obtained, but only one, xyl3, was unable to use fructose and had no phosphoenolpuryvate:fructose phosphotransferase system (fructose-pts) activity. amplification and sequencing of the fructose permease gene of mutant xyl3 revealed the presence of an a ... | 2000 | 10974110 |
| programmed death in bacteria. | programmed cell death (pcd) in bacteria plays an important role in developmental processes, such as lysis of the mother cell during sporulation of bacillus subtilis and lysis of vegetative cells in fruiting body formation of myxococcus xanthus. the signal transduction pathway leading to autolysis of the mother cell includes the terminal sporulation sigma factor esigma(k), which induces the synthesis of autolysins cwlc and cwlh. an activator of autolysin in this and other pcd processes is yet to ... | 2000 | 10974124 |
| molecular cloning and characterization of two genes for the biotin carboxylase and carboxyltransferase subunits of acetyl coenzyme a carboxylase in myxococcus xanthus. | we have cloned a dna fragment from a genomic library of myxococcus xanthus using an oligonucleotide probe representing conserved regions of biotin carboxylase subunits of acetyl coenzyme a (acetyl-coa) carboxylases. the fragment contained two open reading frames (orf1 and orf2), designated the accb and acca genes, capable of encoding a 538-amino-acid protein of 58.1 kda and a 573-amino-acid protein of 61.5 kda, respectively. the protein (acca) encoded by the acca gene was strikingly similar to b ... | 2000 | 10986250 |
| type iv pilus of myxococcus xanthus is a motility apparatus controlled by the frz chemosensory system. | although flagella are the best-understood means of locomotion in bacteria [1], other bacterial motility mechanisms must exist as many diverse groups of bacteria move without the aid of flagella [2-4]. one unusual structure that may contribute to motility is the type iv pilus [5,6]. genetic evidence indicates that type iv pili are required for social gliding motility (s-motility) in myxococcus, and twitching motility in pseudomonas and neisseria [6,7]. it is thought that type iv pili may retract ... | 2000 | 10996798 |
| social motility in myxococcus xanthus requires frzs, a protein with an extensive coiled-coil domain. | gliding motility in the developmental bacterium myxococcus xanthus involves two genetically distinct motility systems, designated adventurous (a) and social (s). directed motility responses, which facilitate both vegetative swarming and developmental aggregation, additionally require the 'frizzy' (frz) signal transduction pathway. in this study, we have analysed a new gene (frzs), which is positioned upstream of the frza-f operon. insertion mutations in frzs caused both vegetative spreading and ... | 2000 | 10998168 |
| myxococcus xanthus dif genes are required for biogenesis of cell surface fibrils essential for social gliding motility. | myxococcus xanthus social (s) gliding motility has been previously reported by us to require the chemotaxis homologues encoded by the dif genes. in addition, two cell surface structures, type iv pili and extracellular matrix fibrils, are also critical to m. xanthus s motility. we have demonstrated here that m. xanthus dif genes are required for the biogenesis of fibrils but not for that of type iv pili. furthermore, the developmental defects of dif mutants can be partially rescued by the additio ... | 2000 | 11004179 |
| myxococcus xanthus fibril appendages are essential for excitation by a phospholipid attractant. | isolated (a-motile) myxococcus xanthus cells glide over solid surfaces and display excitation, a suppression of direction reversals, when presented with phosphatidylethanolamine (pe) purified from its own membranes or synthetic dilauroyl pe and dioleoyl pe. although the mechanism of pe signal transduction is unknown, we hypothesized that m. xanthus might use surface-associated factors to detect exogenous pe to prevent endogenous lipids from self-stimulating the sensory system. peritrichous prote ... | 2000 | 11016978 |
| evolution of viruses by acquisition of cellular rna or dna nucleotide sequences and genes: an introduction. | the origins of virus evolution may be traced to archeabacteria since inouye and inouye (6) discovered a retroelement with a gene for reverse transcriptase in the bacterial genome and in the satellite, multiple copy single stranded dna (msdna) in the soil bacterium myxococcus xanthus. it was possible (8) to define the evolution of retroelements in eukaryotic cells of plants, insects (gypsy retrovirus) and vertebrates. the replication of rna viruses in eukaryotic cells allowed for the viral rna ge ... | 2000 | 11022785 |
| cloning and expression of isocitrate lyase from human round worm strongyloides stercoralis. | a full length cdna (1463 bp) encoding isocitrate lyase (ec 4.1.3.1) of strongyloides stercoralis is described. the nucleotide sequence of this insert identified a cdna coding for the isocitrate lyase. the conceptually translated amino acid sequence of the open reading frame for s. stercoralis isocitrate lyase encodes a 450 amino acid residue protein with an apparent molecular weight of 50 kda and a predicted pl of 6.39. the sequence is 69% a/t, reflecting a characteristic a/t codon bias of s. st ... | 2000 | 11031761 |
| effect of the adhesive antibiotic ta on adhesion and initial growth of e. coli on silicone rubber. | catheter-associated urinary tract infection is the most common nosocomial infection, and contributes to patient morbidity and mortality. we investigated the effect that the ta adhesive antibiotic had on adhesion and initial growth in urine of escherichia coli on silicone rubber. the ta antibiotic had reduced adhesion, and inhibited initial growth of the bacteria on the surface. since adhesion and initial growth on the surface are an essential part of biofilm formation and subsequent infection, w ... | 2000 | 11040435 |
| [frua, a transcription factor in myxococus xamthus, regulates transcription of target genes in collaboration with the associated protein frub]. | many developmental genes are regulated by frua, a transcription factor essential for the development of myxococus xamthus. another protein, designated frub, was purified from myxobacteria by its affinity to frua. frub could be phosphorylated by protein kinase(s) located in cell membrane. gel shift assay showed that frua regulates transcription of target genes in collaboration with phosphorylated frub. this study may shed light on the molecular mechanisms of regulatory network involved in the dev ... | 2000 | 11057053 |
| phenotypic analyses of frz and dif double mutants of myxococcus xanthus. | myxococcus xanthus is a gram-negative gliding bacterium that aggregates and develops into multicellular fruiting bodies in response to starvation. two chemosensory systems (frz and dif), both of which are homologous to known chemotaxis proteins, were previously identified through characterization of various developmental mutants. this study aims to examine the interaction between these two systems since both of them are required for fruiting body formation of m. xanthus. through detailed phenoty ... | 2000 | 11064197 |
| mechanisms of apoptosis. | programmed cell death plays critical roles in a wide variety of physiological processes during fetal development and in adult tissues. in most cases, physiological cell death occurs by apoptosis as opposed to necrosis. defects in apoptotic cell death regulation contribute to many diseases, including disorders where cell accumulation occurs (cancer, restenosis) or where cell loss ensues (stroke, heart failure, neurodegeneration, aids). in recent years, the molecular machinery responsible for apop ... | 2000 | 11073801 |
| developmental aggregation of myxococcus xanthus requires frga, an frz-related gene. | myxococcus xanthus is a gram-negative bacterium which has a complex life cycle that includes multicellular fruiting body formation. frizzy mutants are characterized by the formation of tangled filaments instead of hemispherical fruiting bodies on fruiting agar. mutations in the frz genes have been shown to cause defects in directed motility, which is essential for both vegetative swarming and fruiting body formation. in this paper, we report the discovery of a new gene, called frga (for frz-rela ... | 2000 | 11073903 |
| control of asge expression during growth and development of myxococcus xanthus. | one of the earliest events in the myxococcus xanthus developmental cycle is production of an extracellular cell density signal called a-signal (or a-factor). previously, we showed that cells carrying an insertion in the asge gene fail to produce normal levels of this cell-cell signal. in this study we found that expression of asge is growth phase regulated and developmentally regulated. several lines of evidence indicate that asge is cotranscribed with an upstream gene during development. using ... | 2000 | 11073904 |
| identification of a substrate for pkn2, a protein ser/thr kinase from myxococcus xanthus by a novel method for substrate identification. | eukaryotic cells contain a large number of protein ser/ thr kinases, which play important roles in signal transduction required for cell proliferation, differentiation, and stress response and adaptation. it is also known that some prokaryotes contain a family of protein ser/thr kinases. a major challenge in the characterization of these kinases is how to identify their specific substrates. here we developed such a method using a protein ser/thr kinase, pkn2 from myxococcus xanthus, a gram-negat ... | 2000 | 11075932 |
| a large family of eukaryotic-like protein ser/thr kinases of myxococcus xanthus, a developmental bacterium. | myxococcus xanthus is a gram-negative bacterium that forms multicellular fruiting bodies upon starvation. here, we demonstrate that it contains at least 13 eukaryotic-like protein ser/thr kinases (pkn1 to pkn13) individually having unique features. all contain the kinase domain of approximately 280 residues near the n-terminal end, which share highly conserved features in eukaryotic ser/thr kinases. the kinase domain is followed by a putative regulatory domain consisting of 185 to 692 residues. ... | 2000 | 11087177 |
| inorganic polyphosphate kinase and adenylate kinase participate in the polyphosphate:amp phosphotransferase activity of escherichia coli. | polyphosphate kinase (ppk), responsible for the processive synthesis of inorganic polyphosphate (polyp) from atp in escherichia coli, can transfer in reverse the terminal phosphate residue of polyp to adp to yield atp. polyp also serves as a donor in a polyp:amp phosphotransferase (pap) activity observed in extracts of acinetobacter johnsonii and myxococcus xanthus. we have found that overexpression of the gene encoding ppk results in a large enhancement of pap activity in e. coli. the pap activ ... | 2000 | 11106368 |
| 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 |
| 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 |
| 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 |
| [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 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 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |