| 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 |
| development of an environmental functional gene microarray for soil microbial communities. | functional attributes of microbial communities are difficult to study, and most current techniques rely on dna- and rrna-based profiling of taxa and genes, including microarrays containing sequences of known microorganisms. to quantify gene expression in environmental samples in a culture-independent manner, we constructed an environmental functional gene microarray (e-fga) consisting of 13,056 mrna-enriched anonymous microbial clones from diverse microbial communities to profile microbial gene ... | 2010 | 20851978 |
| independent evolution of six families of halogenating enzymes. | halogenated natural products are widespread in the environment, and the halogen atoms are typically vital to their bioactivities. thus far, six families of halogenating enzymes have been identified: cofactor-free haloperoxidases (hpo), vanadium-dependent haloperoxidases (v-hpo), heme iron-dependent haloperoxidases (hi-hpo), non-heme iron-dependent halogenases (ni-hg), flavin-dependent halogenases (f-hg), and s-adenosyl-l-methionine (sam)-dependent halogenases (s-hg). however, these halogenating ... | 2016 | 27153321 |
| antimicrobial peptides from marine proteobacteria. | after years of inadequate use and the emergence of multidrug resistant (mdr) strains, the efficiency of "classical" antibiotics has decreased significantly. new drugs to fight mdr strains are urgently needed. bacteria hold much promise as a source of unusual bioactive metabolites. however, the potential of marine bacteria, except for actinomycetes and cyanobacteria, has been largely underexplored. in the past two decades, the structures of several antimicrobial compounds have been elucidated in ... | 2013 | 24084784 |
| in silico analysis of methyltransferase domains involved in biosynthesis of secondary metabolites. | secondary metabolites biosynthesized by polyketide synthase (pks) and nonribosomal peptide synthetase (nrps) family of enzymes constitute several classes of therapeutically important natural products like erythromycin, rapamycin, cyclosporine etc. in view of their relevance for natural product based drug discovery, identification of novel secondary metabolite natural products by genome mining has been an area of active research. a number of different tailoring enzymes catalyze a variety of chemi ... | 2008 | 18950525 |
| characterization of a novel type of oxidative decarboxylase involved in the biosynthesis of the styryl moiety of chondrochloren from an acylated tyrosine. | myxobacteria are soil-dwelling bacteria notable for several unique behavioral features, such as cellular movement by gliding and the formation of multicellular fruiting bodies. more recently they have gained recognition as producers of several unique polyketide and nonribosomal polypeptide metabolites with potential therapeutic value. the biosynthesis of these compounds often involves highly unusual mechanisms including the formation of the chloro-hydroxy-styryl moiety of the chondrochloren anti ... | 2010 | 20080978 |
| myxobacteria: natural pharmaceutical factories. | myxobacteria are amongst the top producers of natural products. the diversity and unique structural properties of their secondary metabolites is what make these social microbes highly attractive for drug discovery. screening of products derived from these bacteria has revealed a puzzling amount of hits against infectious and non-infectious human diseases. preying mainly on other bacteria and fungi, why would these ancient hunters manufacture compounds beneficial for us? the answer may be the tar ... | 2012 | 22545867 |
| genome mining in sorangium cellulosum so ce56: identification and characterization of the homologous electron transfer proteins of a myxobacterial cytochrome p450. | myxobacteria, especially members of the genus sorangium, are known for their biotechnological potential as producers of pharmaceutically valuable secondary metabolites. the biosynthesis of several of those myxobacterial compounds includes cytochrome p450 activity. although class i cytochrome p450 enzymes occur wide-spread in bacteria and rely on ferredoxins and ferredoxin reductases as essential electron mediators, the study of these proteins is often neglected. therefore, we decided to search i ... | 2009 | 19696019 |
| jasplakinolide induces apoptosis in various transformed cell lines by a caspase-3-like protease-dependent pathway. | to clarify the mechanisms underlying the antiproliferative effects of jasplakinolide, a cyclic depsipeptide from marine sponges, we examined whether jasplakinolide induces apoptosis in a variety of transformed and nontransformed cells. jasplakinolide inhibited proliferation of human jurkat t cells, resulting in cell death. this was accompanied by chromatin condensation and dna cleavage at the linker regions between the nucleosomes. when caspase-3-like activity in the cytosolic extracts of jurkat ... | 2000 | 11063504 |
| molecular evidence for association between the sphingobacterium-like organism "candidatus comitans" and the myxobacterium chondromyces crocatus. | seven strains of the myxobacterium chondromyces crocatus, isolated from widely separated geographic regions, were investigated for the presence of an associate gram-negative, rod-shaped companion bacterium that is phylogenetically related to the genus sphingobacterium and has been named "candidatus comitans" (c. a. jacobi, e. stackebrandt, h. reichenbach, and b. j. tindall, int. j. syst. bacteriol. 46:119-122, 1996). five of the chondromyces strains were found to be associated with a companion b ... | 1997 | 9023949 |
| planctomycetes as novel source of bioactive molecules. | marine environments are a fruitful source of bioactive compounds some of which are the newest leading drugs in medicinal therapeutics. of particular importance are organisms like sponges and macroalgae and their associated microbiome. planctomycetes, abundant in macroalgae biofilms, are promising producers of bioactive compounds since they share characteristics, like large genomes and complex life cycles, with the most bioactive bacteria, the actinobacteria. furthermore, genome mining revealed t ... | 2016 | 27570520 |
| biotechnology of polyketides: new breath of life for the novel antibiotic genetic pathways discovery through metagenomics. | the discovery of secondary metabolites produced by microorganisms (e.g., penicillin in 1928) and the beginning of their industrial application (1940) opened new doors to what has been the main medication source for the treatment of infectious diseases and tumors. in fact, approximately 80 years after the discovery of the first antibiotic compound, and despite all of the warnings about the failure of the "goose that laid the golden egg," the potential of this wealth is still inexorable: simply ad ... | 2014 | 24688489 |
| biotechnology of polyketides: new breath of life for the novel antibiotic genetic pathways discovery through metagenomics. | the discovery of secondary metabolites produced by microorganisms (e.g., penicillin in 1928) and the beginning of their industrial application (1940) opened new doors to what has been the main medication source for the treatment of infectious diseases and tumors. in fact, approximately 80 years after the discovery of the first antibiotic compound, and despite all of the warnings about the failure of the "goose that laid the golden egg," the potential of this wealth is still inexorable: simply ad ... | 2014 | 24688489 |
| the vein patterning 1 (vep1) gene family laterally spread through an ecological network. | lateral gene transfer (lgt) is a major evolutionary mechanism in prokaryotes. knowledge about lgt- particularly, multicellular- eukaryotes has only recently started to accumulate. a widespread assumption sees the gene as the unit of lgt, largely because little is yet known about how lgt chances are affected by structural/functional features at the subgenic level. here we trace the evolutionary trajectory of vein patterning 1, a novel gene family known to be essential for plant development and de ... | 2011 | 21818306 |
| discovering new bioactive molecules from microbial sources. | there is an increased need for new drug leads to treat diseases in humans, animals and plants. a dramatic example is represented by the need for novel and more effective antibiotics to combat multidrug-resistant microbial pathogens. natural products represent a major source of approved drugs and still play an important role in supplying chemical diversity, despite a decreased interest by large pharmaceutical companies. novel approaches must be implemented to decrease the chances of rediscovering ... | 2014 | 24661414 |
| sponge-associated microorganisms: evolution, ecology, and biotechnological potential. | marine sponges often contain diverse and abundant microbial communities, including bacteria, archaea, microalgae, and fungi. in some cases, these microbial associates comprise as much as 40% of the sponge volume and can contribute significantly to host metabolism (e.g., via photosynthesis or nitrogen fixation). we review in detail the diversity of microbes associated with sponges, including extensive 16s rrna-based phylogenetic analyses which support the previously suggested existence of a spong ... | 2007 | 17554047 |
| concise route to defined stereoisomers of the hydroxy acid of the chondramides. | the use of kobayashi vinylogous aldol reaction in the reaction with acetaldehyde led to anti-aldol product 11. after reductive removal of the chiral auxiliary, the primary alcohol was converted to the allyliodide 14. this compound could be engaged in an evans alkylation reaction, leading eventually to hydroxy acid 19. inclusion of a mitsunobu inversion reaction on the sequence starting with ent-11 led to hydroxy ester 30, featuring a 6,7-syn-configuration. these hydroxy acids should help to eluc ... | 2008 | 22140278 |
| natural products genomics. | | 2008 | 21261848 |
| a selective account of effective paradigms and significant outcomes in the discovery of inspirational marine natural products. | marine natural products continue to be a source of significant molecular structures that serve as a stimulus to seed further significant research. this account reviews some of the major advances in the study of marine biomolecules made at uc santa cruz over more than three decades. the continuing challenge of discovery and characterization of what we term "inspirational molecular structures" will be presented in a comprehensive fashion. examples of privileged molecular structures and their impac ... | 2009 | 19209899 |
| bioactive dehydrotyrosyl and dehydrodopyl compounds of marine origin. | the amino acid, tyrosine, and its hydroxylated product, 3,4-dihydroxyphenylalanine (dopa), plays an important role in the biogenesis of a number of potentially important bioactive molecules in marine organisms. interestingly, several of these tyrosyl and dopa-containing compounds possess dehydro groups in their side chains. examples span the range from simple dehydrotyrosine and dehydrodopamines to complex metabolic products, including peptides and polycyclic alkaloids. based on structural infor ... | 2010 | 21339956 |
| fatty acid-related phylogeny of myxobacteria as an approach to discover polyunsaturated omega-3/6 fatty acids. | in an analysis of 47 aerobic myxobacterial strains, representing 19 genera in suborders cystobacterineae, nannocystineae, sorangiineae, and a novel isolate, "aetherobacter" sbsr008, an enormously diverse array of fatty acids (fas) was found. the distribution of straight-chain fatty acids (scfas) and branched-chain fatty acids (bcfas) supports the reported clustering of strains in the phylogenetic tree based on 16s rrna genes. this finding additionally allows the prediction and assignment of the ... | 2011 | 21317327 |
| new structures and bioactivity properties of jasplakinolide (jaspamide) analogues from marine sponges. | the goal of this study was to isolate and study additional jasplakinolide analogues from two taxonomically distinct marine sponges including two auletta spp. and one jaspis splendens. this led to the isolation of jasplakinolide (1) and eleven jasplakinolide analogues (3-13) including seven new analogues (6-10, 12, and 13). structure elucidation of the new compounds was based on a combination of 1d and 2d nmr analysis, optical rotation, circular dichroism, and preparation of mosher's esters. five ... | 2010 | 20121114 |
| molecular fingerprinting by pcr-denaturing gradient gel electrophoresis reveals differences in the levels of microbial diversity for musty-earthy tainted corks. | the microbial community structure of cork with marked musty-earthy aromas was analyzed using denaturing gradient gel electrophoresis of amplified ribosomal dna. cork stoppers and discs were used for dna extraction and were analyzed by using selective primers for bacteria and fungi. stoppers clearly differed from discs harboring a different fungal community. moreover, musty-earthy samples of both types were shown to have a specific microbiota. the fungi penicillium glabrum and neurospora spp. wer ... | 2009 | 19201983 |
| isolation and characterization of the gene associated with geosmin production in cyanobacteria. | geosmin is a secondary metabolite responsible for earthy tastes and odors in potable water supplies. geosmin continues to be a challenge to water utility management regimes and remains one of the most common causes of consumer complaints, as the taste of "dirty" water may suggest a failed disinfection regime and that the water may be unsafe to drink. although cyanobacteria have been reported to be largely responsible for these taste and odor events, the answer as to how or why geosmin is produce ... | 2008 | 19031897 |
| the role of molecular modeling in the design of analogues of the fungicidal natural products crocacins a and d. | extensive molecular modeling based on crystallographic data was used to aid the design of synthetic analogues of the fungicidal naturally occurring respiration inhibitors crocacins a and d, and an inhibitor binding model to the mammalian cytochrome bc(1) complex was constructed. simplified analogues were made which showed high activity in a mitochondrial beef heart respiration assay, and which were also active against certain plant pathogens in glasshouse tests. a crystal structure was obtained ... | 2008 | 18996700 |
| 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 |
| 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 |
| highlights of marine invertebrate-derived biosynthetic products: their biomedical potential and possible production by microbial associants. | coral reefs are among the most productive marine ecosystems and are the source of a large group of structurally unique biosynthetic products. annual reviews of marine natural products continue to illustrate that the most prolific source of bioactive compounds consist of coral reef invertebrates-sponges, ascidians, mollusks, and bryozoans. this account examines recent milestone developments pertaining to compounds from invertebrates designated as therapeutic leads for biomedical discovery. the fo ... | 2011 | 21835627 |
| explorations of catalytic domains in non-ribosomal peptide synthetase enzymology. | many pharmaceuticals on the market today belong to a large class of natural products called nonribosomal peptides (nrps). originating from bacteria and fungi, these peptide-based natural products consist not only of the 20 canonical l-amino acids, but also non-proteinogenic amino acids, heterocyclic rings, sugars, and fatty acids, generating tremendous chemical diversity. as a result, these secondary metabolites exhibit a broad array of bioactivity, ranging from antimicrobial to anticancer. the ... | 2012 | 22802156 |
| 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 |
| myxobacteria, polarity, and multicellular morphogenesis. | myxobacteria are renowned for the ability to sporulate within fruiting bodies whose shapes are species-specific. the capacity to build those multicellular structures arises from the ability of m. xanthus to organize high cell-density swarms, in which the cells tend to be aligned with each other while constantly in motion. the intrinsic polarity of rod-shaped cells lays the foundation, and each cell uses two polar engines for gliding on surfaces. it sprouts retractile type iv pili from the leadin ... | 2010 | 20610548 |
| waves and aggregation patterns in myxobacteria. | under starvation conditions, a population of myxobacteria aggregates to build a fruiting body whose shape is species-specific and within which the cells sporulate. early in this process, cells often pass through a "ripple phase" characterized by traveling linear, concentric, and spiral waves. these waves are different from the waves observed during slime mold aggregation that depend on diffusible morphogens, because myxobacteria communicate by direct contact. the difference is most dramatic when ... | 2004 | 15020771 |
| possibility of bacterial recruitment of plant genes associated with the biosynthesis of secondary metabolites. | | 2003 | 12857798 |
| biosynthesis of α-pyrones. | the α-pyrone moiety is a structural feature found in a huge variety of biologically active metabolites. in recent times new insights into additional biosynthetic mechanisms, yielding in such six-membered unsaturated ester ring residues have been obtained. the purpose of this mini-review is to give a brief overview of α-pyrones and the mechanisms forming the basis of their natural synthesis. especially the chain interconnecting enzymes, showing homology to ketosynthases which catalyze claisen-lik ... | 2016 | 27340449 |
| complete genome of the starch-degrading myxobacteria sandaracinus amylolyticus dsm 53668t. | myxobacteria are members of δ-proteobacteria and are typified by large genomes, well-coordinated social behavior, gliding motility, and starvation-induced fruiting body formation. here, we report the 10.33 mb whole genome of a starch-degrading myxobacterium sandaracinus amylolyticus dsm 53668(t) that encodes 8,962 proteins, 56 trna, and two rrna operons. phylogenetic analysis, in silico dna-dna hybridization and average nucleotide identity reveal its divergence from other myxobacterial species a ... | 2016 | 27358428 |
| the tyrosine aminomutase tam1 is required for β-tyrosine biosynthesis in rice. | non-protein amino acids, often isomers of the standard 20 protein amino acids, have defense-related functions in many plant species. a targeted search for jasmonate-induced metabolites in cultivated rice (oryza sativa) identified (r)-β-tyrosine, an isomer of the common amino acid (s)-α-tyrosine in the seeds, leaves, roots, and root exudates of the nipponbare cultivar. assays with 119 diverse cultivars showed a distinct presence/absence polymorphism, with β-tyrosine being most prevalent in temper ... | 2015 | 25901084 |
| a new member of the 4-methylideneimidazole-5-one-containing aminomutase family from the enediyne kedarcidin biosynthetic pathway. | 4-methylideneimidazole-5-one (mio)-containing aminomutases catalyze the conversion of l-α-amino acids to β-amino acids with either an (r) or an (s) configuration. l-phenylalanine and l-tyrosine are the only two natural substrates identified to date. the enediyne chromophore of the chromoprotein antitumor antibiotic kedarcidin (ked) harbors an (r)-2-aza-3-chloro-β-tyrosine moiety reminiscent of the (s)-3-chloro-5-hydroxy-β-tyrosine moiety of the c-1027 enediyne chromophore, the biosynthesis of wh ... | 2013 | 23633564 |
| exopolysaccharide microchannels direct bacterial motility and organize multicellular behavior. | the myxobacteria are a family of soil bacteria that form biofilms of complex architecture, aligned multilayered swarms or fruiting body structures that are simple or branched aggregates containing myxospores. here, we examined the structural role of matrix exopolysaccharide (eps) in the organization of these surface-dwelling bacterial cells. using time-lapse light and fluorescence microscopy, as well as transmission electron microscopy and focused ion beam/scanning electron microscopy (fib/sem) ... | 2016 | 27152937 |
| genome analysis of the fruiting body-forming myxobacterium chondromyces crocatus reveals high potential for natural product biosynthesis. | here, we report the complete genome sequence of the type strain of the myxobacterial genus chondromyces, chondromyces crocatus cm c5. it presents one of the largest prokaryotic genomes featuring a single circular chromosome and no plasmids. analysis revealed an enlarged set of trna genes, along with reduced pressure on preferred codon usage compared to that of other bacterial genomes. the large coding capacity and the plethora of encoded secondary metabolite biosynthetic gene clusters are in lin ... | 2016 | 26773087 |
| heterologous production of the marine myxobacterial antibiotic haliangicin and its unnatural analogues generated by engineering of the biochemical pathway. | despite their fastidious nature, marine myxobacteria have considerable genetic potential to produce novel secondary metabolites. the marine myxobacterium haliangium ochraceum smp-2 produces the antifungal polyketide haliangicin (1), but its productivity is unsatisfactory. the biosynthetic gene cluster hli (47.8 kbp) associated with 1 was identified and heterologously expressed in myxococcus xanthus to permit the production of 1 with high efficiency (tenfold greater amount and threefold faster in ... | 2016 | 26915413 |
| total synthesis and configurational assignment of chondramide a. | the first total synthesis of the cyclodepsipeptide chondramide a (2 b) is described. this depsipeptide is composed of four subunits, namely l-alanine, n-me-d-tryptophan, 3-amino-2-methoxy-propionic acid (beta-tyrosine derivative), and a 7-hydroxy-alkenoic acid. while the configuration of the stereogenic centers in the 7-hydroxy-alkenoic acid were known, the configuration of the tyrosine derivative required clarification and turned out to be (2s,3r) or (2l,3l), respectively. the synthesis of the ... | 2010 | 20222097 |
| statistical image analysis reveals features affecting fates of myxococcus xanthus developmental aggregates. | starving myxococcus xanthus bacteria use their motility systems to self-organize into multicellular fruiting bodies, large mounds in which cells differentiate into metabolically inert spores. despite the identification of the genetic pathways required for aggregation and the use of microcinematography to observe aggregation dynamics in wt and mutant strains, a mechanistic understanding of aggregation is still incomplete. for example, it is not clear why some of the initial aggregates mature into ... | 2011 | 21436028 |
| biostructural features of additional jasplakinolide (jaspamide) analogues. | the cyclodepsipeptide jasplakinolide (1) (aka jaspamide), isolated previously from the marine sponge jaspis splendens, is a unique cytotoxin and molecular probe that operates through stabilization of filamentous actin (f-actin). we have recently disclosed that two analogues of 1, jasplakinolides b (3) and e, were referred to the national cancer institute's (nci) biological evaluation committee, and the objective of this study was to reinvestigate a fijian collection of j. splendens in an effort ... | 2011 | 21241058 |
| molecular recognition in myxobacterial outer membrane exchange: functional, social and evolutionary implications. | through cooperative interactions, bacteria can build multicellular communities. to ensure that productive interactions occur, bacteria must recognize their neighbours and respond accordingly. molecular recognition between cells is thus a fundamental behaviour, and in bacteria important discoveries have been made. this microreview focuses on a recently described recognition system in myxobacteria that is governed by a polymorphic cell surface receptor called traa. traa regulates outer membrane ex ... | 2013 | 24261719 |
| molecular recognition in myxobacterial outer membrane exchange: functional, social and evolutionary implications. | through cooperative interactions, bacteria can build multicellular communities. to ensure that productive interactions occur, bacteria must recognize their neighbours and respond accordingly. molecular recognition between cells is thus a fundamental behaviour, and in bacteria important discoveries have been made. this microreview focuses on a recently described recognition system in myxobacteria that is governed by a polymorphic cell surface receptor called traa. traa regulates outer membrane ex ... | 2013 | 24261719 |
| scrutinizing the scaffolds of marine biosynthetics from different source organisms: gram-negative cultured bacterial products enter center stage. | compounds from macro marine organisms are presumed to owe their biosynthetic origins to associated microbial symbionts, although few definitive examples exist. an upsurge in the recent literature from 2012 to 2013 has shown that four compounds previously reported from macro marine organisms are in fact biosynthesized by non-photosynthetic gram-negative bacteria (npgnb). structural parallels between compounds isolated from macro marine organisms and npgnb producers form the basis of this review. ... | 2014 | 24571234 |
| how myxobacteria cooperate. | prokaryotes often reside in groups where a high degree of relatedness has allowed the evolution of cooperative behaviors. however, very few bacteria or archaea have made the successful transition from unicellular to obligate multicellular life. a notable exception is the myxobacteria, in which cells cooperate to perform group functions highlighted by fruiting body development, an obligate multicellular function. like all multicellular organisms, myxobacteria face challenges in how to organize an ... | 2015 | 26254571 |
| myxobacteria versus sponge-derived alkaloids: the bengamide family identified as potent immune modulating agents by scrutiny of lc-ms/elsd libraries. | a nuclear factor-κb (nf-κb) luciferase assay has been employed to identify the bengamides, previously known for their anti-tumor activity, as a new class of immune modulators. a unique element of this study was that the bengamide analogs were isolated from two disparate sources, myxococcus virescens (bacterium) and jaspis coriacea (sponge). comparative lc-ms/elsd and nmr analysis facilitated the isolation of m. viriscens derived samples of bengamide e (8) and two congeners, bengamide e' (13) and ... | 2012 | 22705020 |
| enantioselective synthesis of (+)-crocacin c. an example of a highly challenging mismatched double asymmetric δ-stannylcrotylboration reaction. | a concise, enantioselective synthesis of (+)-crocacin c is described, featuring a highly diastereoselective mismatched double asymmetric δ-stannylcrotylboration of the stereochemically demanding chiral aldehyde 9 with the bifunctional crotylborane reagent (s)-e-10. the total synthesis of (+)-crocacin c was accomplished in seven steps (longest linear sequence) starting from commercially available precursors. | 2012 | 22409510 |
| cloning and sequencing of the kedarcidin biosynthetic gene cluster from streptoalloteichus sp. atcc 53650 revealing new insights into biosynthesis of the enediyne family of antitumor antibiotics. | enediyne natural product biosynthesis is characterized by a convergence of multiple pathways, generating unique peripheral moieties that are appended onto the distinctive enediyne core. kedarcidin (ked) possesses two unique peripheral moieties, a (r)-2-aza-3-chloro-β-tyrosine and an iso-propoxy-bearing 2-naphthonate moiety, as well as two deoxysugars. the appendage pattern of these peripheral moieties to the enediyne core in ked differs from the other enediynes studied to date with respect to st ... | 2013 | 23360970 |
| the crystal structure of the adenylation enzyme vinn reveals a unique β-amino acid recognition mechanism. | adenylation enzymes play important roles in the biosynthesis and degradation of primary and secondary metabolites. mechanistic insights into the recognition of α-amino acid substrates have been obtained for α-amino acid adenylation enzymes. the asp residue is invariant and is essential for the stabilization of the α-amino group of the substrate. in contrast, the β-amino acid recognition mechanism of adenylation enzymes is still unclear despite the importance of β-amino acid activation for the bi ... | 2014 | 25246523 |
| targeting the actin cytoskeleton: selective antitumor action via trapping pkcɛ. | targeting the actin cytoskeleton (csk) of cancer cells offers a valuable strategy in cancer therapy. there are a number of natural compounds that interfere with the actin csk, but the mode of their cytotoxic action and, moreover, their tumor-specific mechanisms are quite elusive. we used the myxobacterial compound chondramide as a tool to first elucidate the mechanisms of cytotoxicity of actin targeting in breast cancer cells (mcf7, mda-mb-231). chondramide inhibits cellular actin filament dynam ... | 2014 | 25165884 |
| actin-dynamics in plant cells: the function of actin-perturbing substances: jasplakinolide, chondramides, phalloidin, cytochalasins, and latrunculins. | this chapter gives an overview of the most common f-actin-perturbing substances that are used to study actin dynamics in living plant cells in studies on morphogenesis, motility, organelle movement, or when apoptosis has to be induced. these substances can be divided into two major subclasses: f-actin-stabilizing and -polymerizing substances like jasplakinolide and chondramides and f-actin-severing compounds like chytochalasins and latrunculins. jasplakinolide was originally isolated form a mari ... | 2016 | 26498789 |
| harold clifton urschel, jr., md, lld(hon), ds(hon): a conversation with the editor. interview by william clifford roberts. | | 2003 | 16278704 |
| the actin targeting compound chondramide inhibits breast cancer metastasis via reduction of cellular contractility. | a major player in the process of metastasis is the actin cytoskeleton as it forms key structures in both invasion mechanisms, mesenchymal and amoeboid migration. we tested the actin binding compound chondramide as potential anti-metastatic agent. | 2014 | 25391145 |