| novel iso-branched ether lipids as specific markers of developmental sporulation in the myxobacterium myxococcus xanthus. | iso-fatty acids (fas) are the dominant fa family in all myxobacteria analyzed. furthermore, it was postulated that iso-fas or compounds derived thereof are involved in fruiting body formation in myxococcus xanthus, since mutants with a reduced level of iso-fa due to a reduced level of the precursor isovaleryl-coa, are delayed in aggregation and produce only few myxospores. to elucidate the function of iso-fas and their corresponding lipids we have analyzed the developmental phenotype of mutants ... | 2006 | 16990257 |
| cbga, a protein involved in cortex formation and stress resistance in myxococcus xanthus spores. | cbga plays a role in cortex formation and the acquisition of a subset of stress resistance properties in myxococcus xanthus spores. the cbga mutant produces spores with thin or no cortex layers, and these spores are more sensitive to heat and sodium dodecyl sulfate than their wild-type counterparts. | 2006 | 16997953 |
| reconstitution of the myxothiazol biosynthetic gene cluster by red/et recombination and heterologous expression in myxococcus xanthus. | although many secondary metabolites exhibiting important pharmaceutical and agrochemical activities have been isolated from myxobacteria, most of these microorganisms remain difficult to handle genetically. to utilize their metabolic potential, heterologous expression methodologies are currently being developed. here, the red/et recombination technology was used to perform all required gene cluster engineering steps in escherichia coli prior to the transfer into the chromosome of the heterologou ... | 2006 | 16997979 |
| byssovorax cruenta gen. nov., sp. nov., nom. rev., a cellulose-degrading myxobacterium: rediscovery of 'myxococcus cruentus' thaxter 1897. | a rare, cellulose-decomposing myxobacterium is described, and a new genus name, byssovorax, is proposed for it. the organism is almost certainly identical to the species 'myxococcus cruentus' thaxter 1897, and that species epithet is therefore revived for the novel bacterium: the type strain of byssovorax cruenta gen. nov., sp. nov., nom. rev. is strain by c2(t) (=dsm 14553(t)=cip 108850(t)). the g+c content of its dna is 69.9 mol%. the 16s rrna gene sequence shows that the species belongs to th ... | 2006 | 17012562 |
| novel lipids in myxococcus xanthus and their role in chemotaxis. | organisms that colonize solid surfaces, like myxococcus xanthus, use novel signalling systems to organize multicellular behaviour. phosphatidylethanolamine (pe) containing the fatty acid 16:1omega5 (delta11) elicits a chemotactic response. the phenomenon was examined by observing the effects of pe species with varying fatty acid pairings. wild-type m. xanthus contains 17 different pe species under vegetative conditions and 19 at the midpoint of development; 13 of the 17 have an unsaturated fatty ... | 2006 | 17014493 |
| evolution of sensory complexity recorded in a myxobacterial genome. | myxobacteria are single-celled, but social, eubacterial predators. upon starvation they build multicellular fruiting bodies using a developmental program that progressively changes the pattern of cell movement and the repertoire of genes expressed. development terminates with spore differentiation and is coordinated by both diffusible and cell-bound signals. the growth and development of myxococcus xanthus is regulated by the integration of multiple signals from outside the cells with physiologi ... | 2006 | 17015832 |
| proteome analysis of myxococcus xanthus by off-line two-dimensional chromatographic separation using monolithic poly-(styrene-divinylbenzene) columns combined with ion-trap tandem mass spectrometry. | myxobacteria are potent producers of secondary metabolites exhibiting diverse biological activities and pharmacological potential. the proteome of myxococcus xanthus dk1622 was characterized by two-dimensional chromatographic separation of tryptic peptides from a lysate followed by tandem mass spectrometric identification. the high degree of orthogonality of the separation system employing polymer-based strong cation-exchange and monolithic reversed-phase stationary phases was clearly demonstrat ... | 2006 | 17022647 |
| lysophosphatidylethanolamine is a substrate for the short-chain alcohol dehydrogenase soca from myxococcus xanthus. | short-chain alcohol dehydrogenases (scadhs) synthesize a variety of intercellular signals and other chemically diverse products. it is difficult to predict the substrate of a scadh on the basis of amino acid sequence homology, as the substrates are not known for most scadhs. in myxococcus xanthus, the scadh csga is responsible for c signaling during fruiting body development, although the mechanism is unclear. overexpression of the scadh soca compensates for the lack of csga and restores develop ... | 2006 | 17028273 |
| crystal structure of protoporphyrinogen oxidase from myxococcus xanthus and its complex with the inhibitor acifluorfen. | protoporphyrinogen ix oxidase, a monotopic membrane protein, which catalyzes the oxidation of protoporphyrinogen ix to protoporphyrin ix in the heme/chlorophyll biosynthetic pathway, is distributed widely throughout nature. here we present the structure of protoporphyrinogen ix oxidase from myxococcus xanthus, an enzyme with similar catalytic properties to human protoporphyrinogen ix oxidase that also binds the common plant herbicide, acifluorfen. in the native structure, the planar porphyrinoge ... | 2006 | 17046834 |
| beta-d-allose inhibits fruiting body formation and sporulation in myxococcus xanthus. | myxococcus xanthus, a gram-negative soil bacterium, responds to amino acid starvation by entering a process of multicellular development which culminates in the assembly of spore-filled fruiting bodies. previous studies utilizing developmental inhibitors (such as methionine, lysine, or threonine) have revealed important clues about the mechanisms involved in fruiting body formation. we used biolog phenotype microarrays to screen 384 chemicals for complete inhibition of fruiting body development ... | 2007 | 17056749 |
| a three-dimensional model of myxobacterial fruiting-body formation. | myxobacterial cells are social; they swarm by gliding on surfaces as they feed cooperatively. when they sense starvation, tens of thousands of cells change their movement pattern from outward spreading to inward concentration and form aggregates that become fruiting bodies. cells inside fruiting bodies differentiate into round, nonmotile, environmentally resistant spores. traditionally, cell aggregation has been considered to imply chemotaxis, a long-range cell interaction that shares many featu ... | 2006 | 17088558 |
| xanthusbase: adapting wikipedia principles to a model organism database. | xanthusbase (http://www.xanthusbase.org) is the official model organism database (mod) for the social bacterium myxococcus xanthus. in many respects, m.xanthus represents the pioneer model organism (mo) for studying the genetic, biochemical, and mechanistic basis of prokaryotic multicellularity, a topic that has garnered considerable attention due to the significance of biofilms in both basic and applied microbiology research. to facilitate its utility, the design of xanthusbase incorporates ope ... | 2007 | 17090585 |
| aggregation during fruiting body formation in myxococcus xanthus is driven by reducing cell movement. | when starved, myxococcus xanthus cells assemble themselves into aggregates of about 10(5) cells that grow into complex structures called fruiting bodies, where they later sporulate. here we present new observations on the velocities of the cells, their orientations, and reversal rates during the early stages of fruiting body formation. most strikingly, we find that during aggregation, cell velocities slow dramatically and cells orient themselves in parallel inside the aggregates, while later cel ... | 2007 | 17098901 |
| the unique dkxanthene secondary metabolite family from the myxobacterium myxococcus xanthus is required for developmental sporulation. | under starvation conditions myxobacteria form multicellular fruiting bodies in which vegetative cells differentiate into heat- and desiccation-resistant myxospores. myxobacteria in general are a rich source of secondary metabolites that often exhibit biological activities rarely found in nature. although the involvement of a yellow compound in sporulation and fruiting body formation of myxococcus xanthus was described almost 30 years ago, the chemical principle of the pigment remained elusive. t ... | 2006 | 17148609 |
| gliding motility and polarized slime secretion. | myxococcus leaves a trail of slime on agar as it moves. a filament of slime can be seen attached to the end of a cell, but it is seen only at one end at any particular moment. to identify genes essential for a motility, transposon insertion mutations with defective a motility were studied. fifteen of the 33 mutants had totally lost a motility. all these mutant cells had filaments of slime emerging from both ends, indicating that bipolar secretion prevents a motility. the remaining 18 a motility ... | 2007 | 17176257 |
| adaptation of salt-tolerant myxococcus strains and their motility systems to the ocean conditions. | more and more studies have indicated that myxobacteria are able to live in seawater conditions, which, however, can decrease the fruiting body formation ability and also the adventurous (a) and social (s) motility systems of the myxobacteria. to learn the adaptation mechanism of the salt-tolerant myxobacteria to marine conditions, we analyzed 10 salt-tolerant myxococcus strains of their fruiting body formation and motility. the isolates were from marine samples and possessed different levels of ... | 2007 | 17186141 |
| mutations of the act promoter in myxococcus xanthus. | mutations within the -12 and -24 elements provide evidence that the act promoter is recognized by sigma-54 rna polymerase. deletion of the -20 base pair, which lies between the two conserved elements of sigma-54 promoters, decreased expression by 90%. in addition, mutation of a potential enhancer sequence, around -120, led to an 80% reduction in act gene expression. actb, the second gene in the act operon, encodes a sigma-54 activator protein that is proposed to be an enhancer-binding protein fo ... | 2007 | 17189369 |
| structural basis for operator and antirepressor recognition by myxococcus xanthus cara repressor. | blue light induces carotenogenesis in myxococcus xanthus. the carb operon encodes all but one of the structural genes involved, and its expression is regulated by the cara-cars repressor-antirepressor pair. in the dark, cara-operator binding represses carb. cars, produced on illumination, interacts physically with cara to dismantle the cara-operator complex and activate carb. both operator and cars bind to the autonomously folded n-terminal domain of cara, cara(nter), which in excess represses c ... | 2007 | 17233828 |
| recombination in the vicinity of insertions of transposon tn 5 in myxococcus xanthus. | to test genetic recombination in the vicinity of insertions of the transposon tn5, crosses were performed by transduction between m. xanthus strains carrying different insertions of tn5. one member of each pair carried resistance to kanamycin (tn5-km); the other carried resistance to tetracycline (tn5-tc). the distance between each pair of tn5 insertions was also measured by restriction mapping. the physical distance corresponding to each recombination frequency was calculated from the transduct ... | 1983 | 17246160 |
| genic and allelic interactions in the carotenogenic response of myxococcus xanthus to blue light. | in the bacterium myxococcus xanthus, the synthesis of carotenoids requires illumination with blue light. this stimulates transcription of the carb locus, which is positively required for carotenogenesis. mutations at the carr locus and the only mutation known at cara cause constitutive expression of carb and thus remove the light requirement for carotenoid accumulation (car(c) phenotype). the carr locus is unlinked, and cara is linked, to carb. we have now identified a novel class of car mutatio ... | 1989 | 17246505 |
| strict specificity for high-mannose type n-glycans and primary structure of a red alga eucheuma serra lectin. | we have elucidated the carbohydrate-binding profile of a non-monosaccharide-binding lectin named eucheuma serra lectin (esa)-2 from the red alga eucheuma serra using a lectin-immobilized column and a centrifugal ultrafiltration-high performance liquid chromatography method with a variety of fluorescence-labeled oligosaccharides. in both methods, esa-2 exclusively bound with high-mannose type (hm) n-glycans, but not with any of other n-glycans including complex type, hybrid type and core pentasac ... | 2007 | 17259190 |
| maintenance of endemicity in urban environments: a hypothesis linking risk, network structure and geography. | in industrialised countries, a rapid epidemic phase of hiv transmission has largely given way to more moderated endemic transmission. the dynamics of endemic transmission may differ substantially from those generating epidemic spread. we hypothesise that three elements play an important role in maintaining endemicity in high prevalence urban environments. first, persons are likely to be subject to multiple risks from multiple sources rather than engaging in a single, hierarchically classified, r ... | 2007 | 17283360 |
| microbiology. bright insight into bacterial gliding. | | 2007 | 17289965 |
| evidence that focal adhesion complexes power bacterial gliding motility. | the bacterium myxococcus xanthus has two motility systems: s motility, which is powered by type iv pilus retraction, and a motility, which is powered by unknown mechanism(s). we found that a motility involved transient adhesion complexes that remained at fixed positions relative to the substratum as cells moved forward. complexes assembled at leading cell poles and dispersed at the rear of the cells. when cells reversed direction, the a-motility clusters relocalized to the new leading poles toge ... | 2007 | 17289998 |
| identification of major sporulation proteins of myxococcus xanthus using a proteomic approach. | myxococcus xanthus is a soil-dwelling, gram-negative bacterium that during nutrient deprivation is capable of undergoing morphogenesis from a vegetative rod to a spherical, stress-resistant spore inside a domed-shaped, multicellular fruiting body. to identify proteins required for building stress-resistant m. xanthus spores, we compared the proteome of liquid-grown vegetative cells with the proteome of mature fruiting body spores. two proteins, protein s and protein s1, were differentially expre ... | 2007 | 17293425 |
| lipolytic enzymes in myxococcus xanthus. | the genome of myxococcus xanthus encodes lipolytic enzymes in three different families: patatin lipases, alpha/beta hydrolases, and gdsl lipases. one member of each family was characterized. the protein encoded by mxan_3852 contains motifs characteristic of patatins. mxan_5522 encodes a protein with the g-x-s-x-g motif characteristic of the lipase subfamily of alpha/beta hydrolases. mxan_4569 encodes a member of the gdsl family of lipolytic enzymes. strains with deletions of mxan_5522 and mxan_4 ... | 2007 | 17307851 |
| primary structure and carbohydrate binding specificity of a potent anti-hiv lectin isolated from the filamentous cyanobacterium oscillatoria agardhii. | the primary structure of a lectin, designated oscillatoria agardhii agglutinin (oaa), isolated from the freshwater cyanobacterium o. agardhii nies-204 was determined by the combination of edman degradation and electron spray ionization-mass spectrometry. oaa is a polypeptide (mr 13,925) consisting of two tandem repeats. interestingly, each repeat sequence of oaa showed a high degree of similarity to those of a myxobacterium, myxococcus xanthus hemagglutinin, and a marine red alga eucheuma serra ... | 2007 | 17314091 |
| heat-shock sigma factor rpoh from geobacter sulfurreducens. | recent studies with myxococcus xanthus have suggested that homologues of the escherichia coli heat-shock sigma factor, rpoh, may not be involved in the heat-shock response in this delta-proteobacterium. the genome of another delta-proteobacterium, geobacter sulfurreducens, which is considered to be a representative of the fe(iii)-reducing geobacteraceae that predominate in a diversity of subsurface environments, contains an rpoh homologue. characterization of the g. sulfurreducens rpoh homologue ... | 2007 | 17322204 |
| bithiazole metabolites from the myxobacterium myxococcus fulvus. | two new bithiazole metabolites (3, 4) along with the previously reported compounds (1, 2) were isolated from the culture broth of the gliding bacterium myxococcus fulvus collected from a korean soil. the structures of these compounds were determined to be analogous to myxothiazole a on the basis of combined spectroscopic analyses. the new compounds exhibited significant cytotoxicity and moderate antifungal activity against the mouse fibloblast cell-line l929 and candida albicans, respectively. t ... | 2007 | 17329897 |
| the structure of the escherichia coli nucleoside diphosphate kinase reveals a new quaternary architecture for this enzyme family. | nucleoside diphosphate kinase (ndpk) catalyzes the transfer of gamma-phosphate from nucleoside triphosphates to nucleoside diphosphates. the subunit folding and the dimeric basic structural unit are remarkably the same for available structures but, depending on species, dimers self-associate to form hexamers or tetramers. the crystal structure of the escherichia coli ndpk reveals a new tetrameric quaternary structure for this protein family. the two tetramers differ by the relative orientation o ... | 2007 | 17330300 |
| 3-hydroxy-3-methylglutaryl-coa-like synthases direct the formation of methyl and ethyl side groups in the biosynthesis of the antibiotic myxovirescin a. | | 2007 | 17330904 |
| regulation of dev, an operon that includes genes essential for myxococcus xanthus development and crispr-associated genes and repeats. | expression of dev genes is important for triggering spore differentiation inside myxococcus xanthus fruiting bodies. dna sequence analysis suggested that dev and cas (crispr-associated) genes are cotranscribed at the dev locus, which is adjacent to crispr (clustered regularly interspaced short palindromic repeats). analysis of rna from developing m. xanthus confirmed that dev and cas genes are cotranscribed with a short upstream gene and at least two repeats of the downstream crispr, forming the ... | 2007 | 17369305 |
| genome-wide high-throughput mining of natural-product biosynthetic gene clusters by phage display. | we have developed a phage-display method for high-throughput mining of bacterial gene clusters encoding the natural-product biosynthetic enzymes, polyketide synthases (pkss) and nonribosomal peptide synthetases (nrpss). this method uses the phosphopantetheinyl transferase activity of sfp to specifically biotinylate nrps and pks carrier-protein domains expressed from a library of random genome fragments fused to a gene encoding a phage coat protein. subsequently, the biotinylated phages are enric ... | 2007 | 17379145 |
| a scaleable manufacturing process for pro-ep-b2, a cysteine protease from barley indicated for celiac sprue. | celiac sprue is an inflammatory disease of the small intestine triggered by ingestion of dietary gluten, a family of glutamine and proline rich proteins found in common foodgrains such as wheat, rye, and barley. one potential therapy for this lifelong disease anticipates using an oral protease to detoxify gluten in vivo. recent studies have shown that ep-b2 (endoprotease b, isoform 2) from barley is a promising example of such a glutenase, thus warranting its large-scale production for animal sa ... | 2007 | 17385743 |
| ecological variables affecting predatory success in myxococcus xanthus. | the feeding efficiency of microbial predators depends on both the availability of various prey species and abiotic variables. myxococcus xanthus is a bacterial predator that searches for microbial prey by gliding motility, and then kills and lyses its prey with secreted compounds. we manipulated three ecological variables to examine their effects on the predatory performance of m. xanthus to better understand its behavior and how it affects prey populations. experiments were designed to determin ... | 2007 | 17410395 |
| consolidation of degraded ornamental porous limestone stone by calcium carbonate precipitation induced by the microbiota inhabiting the stone. | although it has already been shown that calcareous stone can be consolidated by using a bacterially inoculated culture medium, a more user-friendly method is the in situ application of a sterile culture medium that is able to activate, among the microbial community of the stone, those bacteria with a potential for calcium carbonate precipitation. in order to test this new method for stone consolidation, non-sterilized decayed porous limestone was immersed in sterile nutritional media. results we ... | 2007 | 17418886 |
| biology by numbers: mathematical modelling in developmental biology. | in recent years, mathematical modelling of developmental processes has earned new respect. not only have mathematical models been used to validate hypotheses made from experimental data, but designing and testing these models has led to testable experimental predictions. there are now impressive cases in which mathematical models have provided fresh insight into biological systems, by suggesting, for example, how connections between local interactions among system components relate to their wide ... | 2007 | 17440530 |
| characterization of safc, a catechol 4-o-methyltransferase involved in saframycin biosynthesis. | members of the saframycin/safracin/ecteinascidin family of peptide natural products are potent antitumor agents currently under clinical development. saframycin mx1, from myxococcus xanthus, is synthesized by a nonribosomal peptide synthetase, safab, and an o-methyltransferase, safc, although other proteins are likely involved in the pathway. safc was overexpressed in escherichia coli, purified to homogeneity, and assayed for its ability to methylate a variety of substrates. safc was able to cat ... | 2007 | 17449703 |
| combinatorial regulation of genes essential for myxococcus xanthus development involves a response regulator and a lysr-type regulator. | myxococcus xanthus is a bacterium that undergoes multicellular development. c-signaling influences gene expression and movement of cells into aggregates. expression of the dev operon, which includes genes essential for efficient sporulation, depends in part on c-signaling and reaches its highest level in cells within aggregates, ensuring that spores form within fruiting bodies. here, an upstream dna element was found to be essential for dev promoter activity and was bound by frua, a response reg ... | 2007 | 17470804 |
| differential expression of the three multicopper oxidases from myxococcus xanthus. | myxococcus xanthus is a soil bacterium that undergoes a unique life cycle among the prokaryotes upon starvation, which includes the formation of macroscopic structures, the fruiting bodies, and the differentiation of vegetative rods into coccoid myxospores. this peculiarity offers the opportunity to study the copper response in this bacterium in two different stages. in fact, m. xanthus vegetative rods exhibit 15-fold-greater resistance against copper than developing cells. however, cells pre-ad ... | 2007 | 17483223 |
| multicellular development in myxococcus xanthus is stimulated by predator-prey interactions. | myxococcus xanthus is a predatory bacterium that exhibits complex social behavior. the most pronounced behavior is the aggregation of cells into raised fruiting body structures in which cells differentiate into stress-resistant spores. in the laboratory, monocultures of m. xanthus at a very high density will reproducibly induce hundreds of randomly localized fruiting bodies when exposed to low nutrient availability and a solid surface. in this report, we analyze how m. xanthus fruiting body deve ... | 2007 | 17513469 |
| an atypical receiver domain controls the dynamic polar localization of the myxococcus xanthus social motility protein frzs. | the myxococcus xanthus frzs protein transits from pole-to-pole within the cell, accumulating at the pole that defines the direction of movement in social (s) motility. here we show using atomic-resolution crystallography and nmr that the frzs receiver domain (rd) displays the conserved switch tyr102 in an unusual conformation, lacks the conserved asp phosphorylation site, and fails to bind mg(2+) or the phosphoryl analogue, mg(2+) x bef(3). mutation of asp55, closest to the canonical site of rd ... | 2007 | 17573816 |
| frzz, a dual chey-like response regulator, functions as an output for the frz chemosensory pathway of myxococcus xanthus. | myxococcus xanthus utilizes two distinct motility systems for movement (gliding) on solid surfaces: adventurous motility (a-motility) and social motility (s-motility). both systems are regulated by the frz signal transduction pathway, which controls cell reversals required for directed motility and fruiting body formation. the frz chemosensory system, unlike the escherichia coli chemotaxis system, contains proteins with multiple response regulator domains: frze, a chea-chey hybrid protein, and f ... | 2007 | 17581122 |
| mutational analysis of the myxovirescin biosynthetic gene cluster reveals novel insights into the functional elaboration of polyketide backbones. | it has been proposed that two acyl carrier proteins (acps)-tab and tae--and two 3-hydroxy-3-methylglutaryl synthases (hmgss)--tac and taf--could constitute two functional acp-hmgs pairs (tab/tac and tae/taf) responsible for the incorporation of acetate and propionate units into the myxovirescin a scaffold, leading to the formation of beta-methyl and beta-ethyl groups, respectively. it has been suggested that three more proteins--tax and tay, which are members of the superfamily of enoyl-coa hydr ... | 2007 | 17583882 |
| two localization motifs mediate polar residence of frzs during cell movement and reversals of myxococcus xanthus. | myxococcus xanthus utilizes two motility systems for surface locomotion: a-motility and s-motility. s-motility is mediated by extension and retraction of type iv pili. cells exhibiting s-motility periodically reverse by switching the assembly of type iv pili from the old leading pole to the new leading pole. these cellular reversals involve regulated pole-to-pole oscillations of the frzs protein. we constructed and characterized in-frame deletion mutations in several frzs domains to determine th ... | 2007 | 17590236 |
| the elusive engine in myxococcus xanthus gliding motility. | bacterial motility is essential for chemotaxis, virulence and complex social interactions leading to biofilm and fruiting body formation. although bacterial swimming in liquids with a flagellum is well understood, little is known regarding bacterial movements across solid surfaces. gliding motility, one such mode of locomotion, has remained largely mysterious because cells move smoothly along their long axis in the absence of any visible organelle. in this review, i discuss recent evidence that ... | 2007 | 17653507 |
| incorporation of nonmethyl branches by isoprenoid-like logic: multiple beta-alkylation events in the biosynthesis of myxovirescin a1. | several polyketide secondary metabolites are predicted to undergo isoprenoid-like beta-alkylations during biosynthesis. one such secondary metabolite is myxovirescin a1, produced by myxococcus xanthus. myxovirescin is of special interest in that it appears to undergo two distinct beta-alkylations. additionally, the myxovirescin biosynthetic gene cluster lacks tandem thiolation domains required in the synthesis of other beta-branched secondary metabolites. to probe the origins of the beta-branche ... | 2007 | 17656320 |
| triple mutants uncover three new genes required for social motility in myxococcus xanthus. | the bacterium myxococcus xanthus glides over surfaces using two different locomotive mechanisms, called s (social) and a (adventurous) motility that enable cells to move both as groups and as individuals. neither mechanism involves flagella. the functions of these two motors are coordinated by the activity of a small ras-like protein, encoded by the mgla gene. the results of previous studies of a second-site suppressor of the mgla-8 missense mutation mask-815 indicate that mgla interacts with a ... | 2007 | 17660550 |
| cooperation of two carotene desaturases in the production of lycopene in myxococcus xanthus. | in myxococcus xanthus, all known carotenogenic genes are grouped together in the gene cluster carb-cara, except for one, crtib (previously named carc). we show here that the first three genes of the carb operon, crte, crtia, and crtb, encode a geranygeranyl synthase, a phytoene desaturase, and a phytoene synthase, respectively. we demonstrate also that crtia possesses cis-to-trans isomerase activity, and is able to dehydrogenate phytoene, producing phytofluene and zeta-carotene. unlike the major ... | 2007 | 17662111 |
| the motors powering a-motility in myxococcus xanthus are distributed along the cell body. | two models have been proposed to explain the adventurous gliding motility of myxococcus xanthus: (i) polar secretion of slime and (ii) an unknown motor that uses cell surface adhesion complexes that form periodic attachments along the cell length. gliding movements of the leading poles of cephalexin-treated filamentous cells were observed but not equivalent movements of the lagging poles. this demonstrates that the adventurous-motility motors are not confined to the rear of the cell. | 2007 | 17704221 |
| the structure of the carbohydrate backbone of the lps from myxococcus xanthus strain dk1622. | gram-negative rod shaped bacterium myxococcus xanthus dk1622 produces a smooth-type lps. the structure of the polysaccharide o-chain and the core-lipid a region of the lps has been determined by chemical and spectroscopic methods. the o-chain was built up of disaccharide repeating units having the following structure: -->6)-alpha-d-glcp-(1-->4)-alpha-d-galpnac6ome*-(1--> with partially methylated galnac residue. the core region consisted of a phosphorylated hexasaccharide, containing one kdo res ... | 2007 | 17709100 |
| new locus important for myxococcus social motility and development. | the mts locus in salt-tolerant myxococcus fulvus hw-1 was found to be critical for gliding motility, fruiting-body formation, and sporulation. the homologous genes in myxococcus xanthus are also important for social motility and fruiting-body development. the mts genes were determined to be involved in cell-cell cohesion in both myxobacterial species. | 2007 | 17720782 |
| proteins associated with the myxococcus xanthus extracellular matrix. | fruiting body formation of myxococcus xanthus, like biofilm formation of many other organisms, involves the production of an extracellular matrix (ecm). while the polysaccharide component has been studied, the protein component has been largely unexplored. proteins associated with the ecm were solubilized from purified ecm by boiling with sodium dodecyl sulfate and were identified by liquid chromatography-tandem mass spectrometry of tryptic fragments. the ecm is enriched in proteins of novel fun ... | 2007 | 17766415 |
| the myxococcus xanthus developmental program can be delayed by inhibition of dna replication. | under conditions of nutrient deprivation, myxococcus xanthus undergoes a developmental process that results in the formation of a fruiting body containing environmentally resistant myxospores. we have shown that myxospores contain two copies of the genome, suggesting that cells must replicate the genome prior to or during development. to further investigate the role of dna replication in development, a temperature-sensitive dnab mutant, dnab(a116v), was isolated from m. xanthus. unlike what happ ... | 2007 | 17905977 |
| the myxococcus xanthus nla4 protein is important for expression of stringent response-associated genes, ppgpp accumulation, and fruiting body development. | changes in gene expression are important for the landmark morphological events that occur during myxococcus xanthus fruiting body development. enhancer binding proteins (ebps), which are transcriptional activators, play prominent roles in the coordinated expression of developmental genes. a mutation in the ebp gene nla4 affects the timing of fruiting body formation, the morphology of mature fruiting bodies, and the efficiency of sporulation. in this study, we showed that the nla4 mutant accumula ... | 2007 | 17905995 |
| spatial organization of myxococcus xanthus during fruiting body formation. | microcinematography was used to examine fruiting body development of myxococcus xanthus. wild-type cells progress through three distinct phases: a quiescent phase with some motility but little aggregation (0 to 8 h), a period of vigorous motility leading to raised fruiting bodies (8 to 16 h), and a period of maturation during which sporulation is initiated (16 to 48 h). fruiting bodies are extended vertically in a series of tiers, each involving the addition of a cell monolayer on top of the upp ... | 2007 | 17921303 |
| chemosensory pathways, motility and development in myxococcus xanthus. | the complex life cycle of myxococcus xanthus includes predation, swarming, fruiting-body formation and sporulation. the genome of m. xanthus is large and comprises an estimated 7,400 open reading frames, of which approximately 605 code for regulatory genes. these include eight clusters of chemotaxis-like genes that define eight chemosensory pathways, most of which have dedicated functions. although many of these chemosensory pathways have a role in controlling motility, at least two of these pat ... | 2007 | 17922045 |
| coupling of protein localization and cell movements by a dynamically localized response regulator in myxococcus xanthus. | myxococcus xanthus cells harbor two motility machineries, type iv pili (tfp) and the a-engine. during reversals, the two machineries switch polarity synchronously. we present a mechanism that synchronizes this polarity switching. we identify the required for motility response regulator (romr) as essential for a-motility. romr localizes in a bipolar, asymmetric pattern with a large cluster at the lagging cell pole. the large romr cluster relocates to the new lagging pole in parallel with cell rev ... | 2007 | 17932488 |
| mutasynthesis-derived myxalamids and origin of the isobutyryl-coa starter unit of myxalamid b. | myxalamids are potent inhibitors of the eukaryotic electron transport chain produced by different myxobacteria. here, we describe the identification of the myxalamid biosynthesis gene cluster from myxococcus xanthus. additionally, new myxalamids (5-13) have been obtained by mutasynthesis from bkd mutants of m. xanthus and stigmatella aurantiaca. moreover, as these bkd mutants are still able to produce myxalamid b (2), the origin of the isobutyryl-coa (ib-coa) starter unit required for its biosyn ... | 2007 | 17955482 |
| complete genome sequence of the myxobacterium sorangium cellulosum. | the genus sorangium synthesizes approximately half of the secondary metabolites isolated from myxobacteria, including the anti-cancer metabolite epothilone. we report the complete genome sequence of the model sorangium strain s. cellulosum so ce56, which produces several natural products and has morphological and physiological properties typical of the genus. the circular genome, comprising 13,033,779 base pairs, is the largest bacterial genome sequenced to date. no global synteny with the genom ... | 2007 | 17965706 |
| polarity of motility systems in myxococcus xanthus. | myxococcus xanthus is a gliding bacterium that contains two motility systems: s-motility, powered by polar type iv pili, and a-motility, powered by uncharacterized motors and adhesion complexes. the localization and coordination of the two motility engines is essential for directed motility as cells move forward and reverse. during cell reversals, the polarity and localization of motility proteins are rapidly inverted, rendering this system a fascinating example of dynamic protein localization. | 2007 | 17981496 |
| the 5' untranslated region of frua mrna is required for translational enhancement of frua synthesis during myxococcus xanthus development. | the frua gene encodes a dna-binding response regulator protein essential for the development of myxococcus xanthus. this gene is transcribed with an unusually long (235 nucleotides) 5' untranslated region (utr) that has been shown to be absolutely necessary for the induction of frua synthesis during development. with lacz as a reporter, it was found in this report that each regional deletion mutation within 5' utr caused a decrease in beta-galactosidase production. base substitution mutations th ... | 2008 | 17992513 |
| bioinformatics and experimental analysis of proteins of two-component systems in myxococcus xanthus. | proteins of two-component systems (tcs) have essential functions in the sensing of external and self-generated signals in bacteria and in the generation of appropriate output responses. accordingly, in myxococcus xanthus, tcs are important for normal motility and fruiting body formation and sporulation. here we analyzed the m. xanthus genome for the presence and genetic organization of genes encoding tcs. two hundred seventy-two tcs genes were identified, 251 of which are not part of che gene cl ... | 2008 | 17993514 |
| chemotaxis mediated by narx-frzcd chimeras and nonadapting repellent responses in myxococcus xanthus. | myxococcus xanthus requires gliding motility for swarming and fruiting body formation. it uses the frz chemosensory pathway to regulate cell reversals. frzcd is a cytoplasmic chemoreceptor required for sensing effectors for this pathway. narx is a transmembrane sensor for nitrate from escherichia coli. in this study, two narx-frzcd chimeras were constructed to investigate m. xanthus chemotaxis: nazd(f) contains the n-terminal sensory module of narx fused to the c-terminal signalling domain of fr ... | 2007 | 18028315 |
| the bacillus and myxococcus developmental networks and their transcriptional regulators. | studies of endospore formation by bacillus subtilis and fruiting body development of myxococcus xanthus have revealed key features of regulatory networks that govern temporal and spatial gene expression in bacteria. in b. subtilis, sigma factor cascades, modulated by other types of transcription factors, regulate genes in two cell types that form and communicate with each other during starvation-induced sporulation. in m. xanthus, starving cells also send signals that alter gene expression, but ... | 2007 | 18076324 |
| identification of (8s,9s,10s)-8,10-dimethyl-1-octalin, a key intermediate in the biosynthesis of geosmin in bacteria. | | 2008 | 18095691 |
| genome evolution and the emergence of fruiting body development in myxococcus xanthus. | lateral gene transfer (lgt) is thought to promote speciation in bacteria, though well-defined examples have not been put forward. | 2007 | 18159227 |
| social interactions in myxobacterial swarming. | swarming, a collective motion of many thousands of cells, produces colonies that rapidly spread over surfaces. in this paper, we introduce a cell-based model to study how interactions between neighboring cells facilitate swarming. we chose to study myxococcus xanthus, a species of myxobacteria, because it swarms rapidly and has well-defined cell-cell interactions mediated by type iv pili and by slime trails. the aim of this paper is to test whether the cell contact interactions, which are inhere ... | 2007 | 18166072 |
| phosphate acquisition components of the myxococcus xanthus pho regulon are regulated by both phosphate availability and development. | in many organisms, phosphatase expression and phosphate (p) uptake are coordinately regulated by the pho regulon. in myxococcus xanthus p limitation initiates multicellular development, a process associated with changes in phosphatase expression. we sought here to characterize the link between p acquisition and development in this bacterium, an organism capable of preying upon other microorganisms as a sole nutrient source. m. xanthus seems to possess no significant internal p stores, as reducin ... | 2008 | 18178740 |
| mazf, an mrna interferase, mediates programmed cell death during multicellular myxococcus development. | in prokaryotes, the toxin-antitoxin systems are thought to play important roles in growth regulation under stress conditions. in the e. coli maze-mazf system, mazf toxin functions as an mrna interferase cleaving mrnas at aca sequences to inhibit protein synthesis leading to cell growth arrest. myxococcus xanthus is a bacterium displaying multicellular fruiting body development during which approximately 80% of cells undergo obligatory cell lysis. here, we demonstrate that m. xanthus has a solita ... | 2008 | 18191220 |
| pilb and pilt are atpases acting antagonistically in type iv pilus function in myxococcus xanthus. | type iv pili (t4p) are dynamic surface structures that undergo cycles of extension and retraction. t4p dynamics center on the pilb and pilt proteins, which are members of the secretion atpase superfamily of proteins. here, we show that pilb and pilt of the t4p system in myxococcus xanthus have atpase activity in vitro. using a structure-guided approach, we systematically mutagenized pilb and pilt to resolve whether both atp binding and hydrolysis are important for pilb and pilt function in vivo. ... | 2008 | 18223089 |
| discovery of the autonomously replicating plasmid pmf1 from myxococcus fulvus and development of a gene cloning system in myxococcus xanthus. | myxobacteria are very important due to their unique characteristics, such as multicellular social behavior and the production of diverse and novel bioactive secondary metabolites. however, the lack of autonomously replicating plasmids has hindered genetic manipulation of myxobacteria for decades. to determine whether indigenous plasmids are present, we screened about 150 myxobacterial strains, and a circular plasmid designated pmf1 was isolated from myxococcus fulvus 124b02. sequence analysis sh ... | 2008 | 18245244 |
| facultative cheater mutants reveal the genetic complexity of cooperation in social amoebae. | cooperation is central to many major transitions in evolution, including the emergence of eukaryotic cells, multicellularity and eusociality. cooperation can be destroyed by the spread of cheater mutants that do not cooperate but gain the benefits of cooperation from others. however, cooperation can be preserved if cheaters are facultative, cheating others but cooperating among themselves. several cheater mutants have been studied before, but no study has attempted a genome-scale investigation o ... | 2008 | 18272966 |
| an anti-antisigma factor in the response of the bacterium myxococcus xanthus to blue light. | cells of the gram-negative bacterium myxococcus xanthus respond to blue light by producing carotenoids, pigments that play a protective role against the oxidative effects of light. blue light triggers a network of regulatory actions that lead to the transcriptional activation of the structural genes for carotenoid synthesis. the product of carf, similar to a family of proteins of unknown function called kua, is an early regulator of this process. previous genetic data indicate that carf particip ... | 2008 | 18310035 |
| vitamin b12 partners the carh repressor to downregulate a photoinducible promoter in myxococcus xanthus. | a light-inducible promoter, p(b), drives expression of the carb operon in myxococcus xanthus. repressed by cara in the dark, p(b) is activated when cars, produced in the light, sequesters cara to prevent operator-cara binding. the merr-type, n-terminal domain of cara, which mediates interactions with both operator and cars, is linked to a c-terminal oligomerization module with a predicted cobalamin-binding motif. here, we show that although cara does bind vitamin b12, mutating the motif involved ... | 2008 | 18315685 |
| residue 134 determines the dimer-tetramer assembly of nucleoside diphosphate kinase from moderately halophilic bacteria. | halomonas nucleoside diphosphate kinase (handk) forms a dimeric assembly and pseudomonas ndk (pandk) forms a tetrameric assembly. the mutation of glu134 to ala in handk resulted in the conversion of the native dimeric structure to the tetramer assembly. conversely, the mutation of ala134 to glu in pandk lead to the conversion from the tetramer to the dimer assembly, indicating that a single amino acid substitution at position 134 results in an alteration of the oligomeric structure of ndk. by mo ... | 2008 | 18319059 |
| isolation by distance in the spore-forming soil bacterium myxococcus xanthus. | genetic differentiation between spatially separated populations within a species is commonly observed in plants and animals, but its existence in microbes has long been a contentious issue. traditionally, many microbial ecologists have reasoned that microbes are not limited by dispersal as a result of their immense numbers and microscopic size. in this view, the absence of barriers to gene flow between populations would prevent differentiation of populations by genetic drift and hinder local ada ... | 2008 | 18328701 |
| 16s rrna gene and 16s-23s rrna gene internal transcribed spacer sequences analysis of the genus myxococcus. | phylogenetic relationships of the species belonging to the genus myxococcus were elucidated based on the sequences of 16s rrna genes and 16s-23s rrna gene internal transcribed spacer (its) regions. the myxococcus species were consequently classified into four distinct groups. the type strain of myxococcus coralloides occupied an independent position (group 1); it has been recently reclassified as corallococcus coralloides. group 2 comprised the type strains of both myxococcus virescens and myxoc ... | 2008 | 18355284 |
| cloning and characterization of an rrna methyltransferase from sorangium cellulosum. | a locus (kmr) responsible for aminoglycosides-resistance of sorangium cellulosum was cloned and characterized in myxococcus xanthus. the gene kmr encodes a putative rrna methyltransferase. expression of the complete orf endowed the myxococcus transformants with the resistance to aminoglycosidic antibiotics of kanamycin, apramycin, gentamycin, neomycin, and tobramycin at an extraordinary high-level (mic, higher than 500 microg/ml). however, the gene did not function in escherichia coli cells. in ... | 2008 | 18355448 |
| discovering the hidden secondary metabolome of myxococcus xanthus: a study of intraspecific diversity. | as a monophyletic group, the myxobacteria are known to produce a broad spectrum of secondary metabolites. however, the degree of metabolic diversity that can be found within a single species remains unexplored. the model species myxococcus xanthus produces several metabolites also present in other myxobacterial species, but only one compound unique to m. xanthus has been found to date. here, we compare the metabolite profiles of 98 m. xanthus strains that originate from 78 locations worldwide an ... | 2008 | 18378661 |
| novel transcriptome patterns accompany evolutionary restoration of defective social development in the bacterium myxococcus xanthus. | evolutionary trait losses can be restored by direct reversion or by compensatory pathways. upon starvation, the bacterium myxococcus xanthus develops into spore-bearing fruiting bodies, but this ability can be rapidly lost during evolution. some developmentally defective strains of m. xanthus "cheat" on proficient strains during development by superior sporulation in mixed cultures. here, we examine transcriptomic patterns accompanying the evolution of a cheater (obligate cheater [oc]) to a deve ... | 2008 | 18385222 |
| espa, an orphan hybrid histidine protein kinase, regulates the timing of expression of key developmental proteins of myxococcus xanthus. | myxococcus xanthus undergoes a complex starvation-induced developmental program that results in cells forming multicellular fruiting bodies by aggregating into mounds and then differentiating into spores. this developmental program requires at least 72 h and is mediated by a temporal cascade of gene regulators in response to intra- and extracellular signals. espa mutants, encoding an orphan hybrid histidine kinase, alter the timing of this developmental program, greatly accelerating developmenta ... | 2008 | 18390653 |
| natural variation of gliding motility in a centimetre-scale population of myxococcus xanthus. | a major challenge in microbial evolutionary ecology is to understand how fitness-related traits vary in natural populations of microorganisms at defined spatial scales and subsequently to identify the forces that maintain such variation. the gram-negative soil bacterium myxococcus xanthus is a model system for the study of gliding motility, which is driven by two complementary motility systems in this species and is central to its social lifestyle. we tested whether the ecological context of a c ... | 2008 | 18410356 |
| the receiver domain of frze, a chea-chey fusion protein, regulates the chea histidine kinase activity and downstream signalling to the a- and s-motility systems of myxococcus xanthus. | the frz chemosensory system is a two-component signal transduction pathway that controls cell reversals and directional movements for the two motility systems in myxococcus xanthus. to trigger cell reversals, frze, a hybrid chea-chey fusion protein, autophosphorylates the kinase domain at his-49, and phosphoryl groups are transferred to aspartate residues (asp-52 and asp-220) in the two receiver domains of frzz, a dual chey-like protein that serves as the pathway output. the role of the receiver ... | 2008 | 18430134 |
| programmed cell death: role for mazf and mrpc in myxococcus multicellular development. | programmed cell death is of ultimate importance in embryonic development of animals. now, programmed cell death has been shown to be an integral part of a multicellular developmental program in the bacterium myxococcus xanthus. | 2008 | 18430632 |
| conversion of the lycopene monocyclase of myxococcus xanthus into a bicyclase. | depending on the cyclized hydrocarbon backbone ends, carotenoids can be acyclic, monocyclic, or bicyclic. lycopene cyclases are the enzymes responsible for catalyzing the formation of cyclic carotenoids from acyclic lycopene. myxococcus xanthus is a bacterium that accumulates monocyclic carotenoids such as a glycoside ester of myxobacton. we show here that this bacterium possesses a cyclase belonging to the group of the heterodimeric cyclases crtyc and crtyd. these two individual proteins are en ... | 2008 | 18437372 |
| protein-protein interactions between two-component system transmitter and receiver domains of myxococcus xanthus. | we present a novel dataset assessing the specificity of protein-protein interactions between 69 transmitter and receiver domains from two-component system (tcs)-signalling pathways. tcs require a conserved protein-protein interaction between partner transmitter and receiver domains for signal transduction. the complex prokaryote myxococcus xanthus possesses an unusually large number of tcs genes, many of which have no obvious interaction partners. interactions between tcs domains of m. xanthus w ... | 2008 | 18442170 |
| the mosaic genome of anaeromyxobacter dehalogenans strain 2cp-c suggests an aerobic common ancestor to the delta-proteobacteria. | anaeromyxobacter dehalogenans strain 2cp-c is a versaphilic delta-proteobacterium distributed throughout many diverse soil and sediment environments. 16s rrna gene phylogenetic analysis groups a. dehalogenans together with the myxobacteria, which have distinguishing characteristics including strictly aerobic metabolism, sporulation, fruiting body formation, and surface motility. analysis of the 5.01 mb strain 2cp-c genome substantiated that this organism is a myxobacterium but shares genotypic t ... | 2008 | 18461135 |
| bacterial development in the fast lane. | | 2008 | 18469109 |
| characterization of a novel bacterial arginine kinase from desulfotalea psychrophila. | phosphagen kinases are found throughout the animal kingdom and catalyze the transfer of a high-energy gamma phosphoryl-group from atp to a guanidino group on a suitable acceptor molecule such as creatine or arginine. recent genome sequencing efforts in several proteobacteria, including desulfotalea psychrophila lsv54, myxococcus xanthus, sulfurovum sp. nbc37-1, and moritella sp. pe36 have revealed what appears to be a phosphagen kinase homolog present in their genomes. based on sequence comparis ... | 2008 | 18499493 |
| two functionally redundant sfp-type 4'-phosphopantetheinyl transferases differentially activate biosynthetic pathways in myxococcus xanthus. | | 2008 | 18506874 |
| independence and interdependence of dif and frz chemosensory pathways in myxococcus xanthus chemotaxis. | dif and frz, two myxococcus xanthus chemosensory pathways, are required in phosphatidylethanolamine (pe) chemotaxis for excitation and adaptation respectively. difa and frzcd, the homologues of methyl-accepting chemoreceptors in the two pathways, were examined for methylation in the context of chemotaxis and inter-pathway interactions. evidence indicates that difa may not undergo methylation, but signals transmitting through difa do modulate frzcd methylation. results also revealed that m. xanth ... | 2008 | 18554324 |
| site-specific receptor methylation of frzcd in myxococcus xanthus is controlled by a tetra-trico peptide repeat (tpr) containing regulatory domain of the frzf methyltransferase. | myxococcus xanthus is a gliding bacterium with a complex life cycle that includes swarming, predation and fruiting body formation. directed movements in m. xanthus are regulated by the frz chemosensory system, which controls cell reversals. the frz pathway requires the activity of frzcd, a cytoplasmic methyl-accepting chemotaxis protein, and frzf, a methyltransferase (cher) containing an additional domain with three tetra trico-peptide repeats (tprs). to investigate the role of the tprs in frzcd ... | 2008 | 18554333 |
| myxococcus-from single-cell polarity to complex multicellular patterns. | myxococcus xanthus creates complex and dynamic multicellular patterns as it swarms. the cells have two polar gliding engines: pulling type iv pili at their leading pole and pushing slime secretory nozzles at their lagging pole. evidence is presented that slime secretion is vital for cell survival and that the peptidoglycan/cytoskeleton serves as a template to keep both engines oriented in the same direction. swarming requires that each cell periodically reverse its gliding direction. for the lea ... | 2008 | 18605899 |
| genetic circuitry controlling motility behaviors of myxococcus xanthus. | m. xanthus has a complex multicellular lifestyle including swarming, predation and development. these behaviors depend on the ability of the cells to achieve directed motility across solid surfaces. m. xanthus cells have evolved two motility systems including type-iv pili that act as grappling hooks and a controversial engine involving mucus secretion and fixed focal adhesion sites. the necessity for cells to coordinate the motility systems and to respond rapidly to environmental cues is reflect ... | 2008 | 18623059 |
| cytoprophet: a cytoscape plug-in for protein and domain interaction networks inference. | cytoprophet is a software tool that allows prediction and visualization of protein and domain interaction networks. it is implemented as a plug-in of cytoscape, an open source software framework for analysis and visualization of molecular networks. cytoprophet implements three algorithms that predict new potential physical interactions using the domain composition of proteins and experimental assays. the algorithms for protein and domain interaction inference include maximum likelihood estimatio ... | 2008 | 18653520 |
| differential expression of a putative card-like transcriptional regulator, ltpa, in borrelia burgdorferi. | the availability of microbial genome information has provided a fruitful opportunity for studying regulatory networks in a variety of pathogenic bacteria. in an initial effort to elucidate regulatory networks potentially involved in differential gene expression by the lyme disease pathogen borrelia burgdorferi, we have been investigating the functions and regulation of putative transcriptional regulatory factors predicted to be encoded within the b. burgdorferi genome. herein we report the regul ... | 2008 | 18663002 |
| efficient transfer of two large secondary metabolite pathway gene clusters into heterologous hosts by transposition. | horizontal gene transfer by transposition has been widely used for transgenesis in prokaryotes. however, conjugation has been preferred for transfer of large transgenes, despite greater restrictions of host range. we examine the possibility that transposons can be used to deliver large transgenes to heterologous hosts. this possibility is particularly relevant to the expression of large secondary metabolite gene clusters in various heterologous hosts. recently, we showed that the engineering of ... | 2008 | 18701643 |
| efficient mining of myxobacterial metabolite profiles enabled by liquid chromatography-electrospray ionisation-time-of-flight mass spectrometry and compound-based principal component analysis. | bacteria producing secondary metabolites are an important source of natural products with highly diverse structures and biological activities. developing methods to efficiently mine procaryotic secondary metabolomes for the presence of potentially novel natural products is therefore of considerable interest. modern mass spectrometry-coupled liquid chromatography can effectively capture microbial metabolic diversity with ever improving sensitivity and accuracy. in addition, computational and stat ... | 2008 | 18706314 |
| dkxanthene biosynthesis--understanding the basis for diversity-oriented synthesis in myxobacterial secondary metabolism. | the dkxanthenes are a family of yellow pigments which play a critical role in myxobacterial development. thirteen unique structures from myxococcus xanthus dk1622 differ in the length of their characteristic polyene functionality, as well as the extent of methyl branching. we aimed to understand the mechanistic basis for this "molecular promiscuity" by analyzing the gene cluster in dk1622, and comparing it to the dkxanthene biosynthetic locus in a second myxobacterium, stigmatella aurantiaca dw4 ... | 2008 | 18721748 |