Hydrogen Peroxide: A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.LaunderingDetergents: Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.Lipid A: Lipid A is the biologically active component of lipopolysaccharides. It shows strong endotoxic activity and exhibits immunogenic properties.Household Products: Substances or materials used in the course of housekeeping or personal routine.Carotenoids: The general name for a group of fat-soluble pigments found in green, yellow, and leafy vegetables, and yellow fruits. They are aliphatic hydrocarbons consisting of a polyisoprene backbone.Saturn: The sixth planet in order from the sun. It is one of the five outer planets of the solar system. Its twelve natural satellites include Phoebe and Titan.Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Body Composition: The relative amounts of various components in the body, such as percentage of body fat.LacquerThermal Conductivity: The heat flow across a surface per unit area per unit time, divided by the negative of the rate of change of temperature with distance in a direction perpendicular to the surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Plastics: Polymeric materials (usually organic) of large molecular weight which can be shaped by flow. Plastic usually refers to the final product with fillers, plasticizers, pigments, and stabilizers included (versus the resin, the homogeneous polymeric starting material). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)PrintingBody Temperature Regulation: The processes of heating and cooling that an organism uses to control its temperature.Convection: Transmission of energy or mass by a medium involving movement of the medium itself. The circulatory movement that occurs in a fluid at a nonuniform temperature owing to the variation of its density and the action of gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed; Webster, 10th ed)Patents as Topic: Exclusive legal rights or privileges applied to inventions, plants, etc.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Adhesives: Substances that cause the adherence of two surfaces. They include glues (properly collagen-derived adhesives), mucilages, sticky pastes, gums, resins, or latex.Heat Exhaustion: A clinical syndrome caused by heat stress, such as over-exertion in a hot environment or excessive exposure to sun. It is characterized by SWEATING, water (volume) depletion, salt depletion, cool clammy skin, NAUSEA, and HEADACHE.Peer Group: Group composed of associates of same species, approximately the same age, and usually of similar rank or social status.Video Games: A form of interactive entertainment in which the player controls electronically generated images that appear on a video display screen. This includes video games played in the home on special machines or home computers, and those played in arcades.Videotape Recording: Recording of visual and sometimes sound signals on magnetic tape.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Journal Impact Factor: A quantitative measure of the frequency on average with which articles in a journal have been cited in a given period of time.Peer Review, Research: The evaluation by experts of the quality and pertinence of research or research proposals of other experts in the same field. Peer review is used by editors in deciding which submissions warrant publication, by granting agencies to determine which proposals should be funded, and by academic institutions in tenure decisions.Peer Review: An organized procedure carried out by a select committee of professionals in evaluating the performance of other professionals in meeting the standards of their specialty. Review by peers is used by editors in the evaluation of articles and other papers submitted for publication. Peer review is used also in the evaluation of grant applications. It is applied also in evaluating the quality of health care provided to patients.Television: The transmission and reproduction of transient images of fixed or moving objects. An electronic system of transmitting such images together with sound over a wire or through space by apparatus that converts light and sound into electrical waves and reconverts them into visible light rays and audible sound. (From Webster, 3rd ed)Publishing: "The business or profession of the commercial production and issuance of literature" (Webster's 3d). It includes the publisher, publication processes, editing and editors. Production may be by conventional printing methods or by electronic publishing.Bibliometrics: The use of statistical methods in the analysis of a body of literature to reveal the historical development of subject fields and patterns of authorship, publication, and use. Formerly called statistical bibliography. (from The ALA Glossary of Library and Information Science, 1983)Streptococcus pneumoniae: A gram-positive organism found in the upper respiratory tract, inflammatory exudates, and various body fluids of normal and/or diseased humans and, rarely, domestic animals.DNA Gyrase: A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Gyrase binds to DNA as a heterotetramer consisting of two A and two B subunits. In the presence of ATP, gyrase is able to convert the relaxed circular DNA duplex into a superhelix. In the absence of ATP, supercoiled DNA is relaxed by DNA gyrase.DNA, Superhelical: Circular duplex DNA isolated from viruses, bacteria and mitochondria in supercoiled or supertwisted form. This superhelical DNA is endowed with free energy. During transcription, the magnitude of RNA initiation is proportional to the DNA superhelicity.DNA Topoisomerases, Type II: DNA TOPOISOMERASES that catalyze ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. These enzymes bring about relaxation of the supercoiled DNA and resolution of a knotted circular DNA duplex.Novobiocin: An antibiotic compound derived from Streptomyces niveus. It has a chemical structure similar to coumarin. Novobiocin binds to DNA gyrase, and blocks adenosine triphosphatase (ATPase) activity. (From Reynolds, Martindale The Extra Pharmacopoeia, 30th ed, p189)Bacterial Proteins: Proteins found in any species of bacterium.DNA Topoisomerase IV: A bacterial DNA topoisomerase II that catalyzes ATP-dependent breakage of both strands of DNA, passage of the unbroken strands through the breaks, and rejoining of the broken strands. Topoisomerase IV binds to DNA as a heterotetramer consisting 2 parC and 2 parE subunits. Topoisomerase IV is a decatenating enzyme that resolves interlinked daughter chromosomes following DNA replication.DNA Topoisomerases, Type I: DNA TOPOISOMERASES that catalyze ATP-independent breakage of one of the two strands of DNA, passage of the unbroken strand through the break, and rejoining of the broken strand. DNA Topoisomerases, Type I enzymes reduce the topological stress in the DNA structure by relaxing the superhelical turns and knotted rings in the DNA helix.Streptococcus pyogenes: A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group A hemolytic Streptococcus that can cause SCARLET FEVER and RHEUMATIC FEVER.Pneumococcal Infections: Infections with bacteria of the species STREPTOCOCCUS PNEUMONIAE.Peptide Synthases: Ligases that catalyze the joining of adjacent AMINO ACIDS by the formation of carbon-nitrogen bonds between their carboxylic acid groups and amine groups.Polyketide Synthases: Large enzyme complexes composed of a number of component enzymes that are found in STREPTOMYCES which biosynthesize MACROLIDES and other polyketides.Peptide Biosynthesis, Nucleic Acid-Independent: The enzymatic synthesis of PEPTIDES without an RNA template by processes that do not use the ribosomal apparatus (RIBOSOMES).Polyketides: Natural compounds containing alternating carbonyl and methylene groups (beta-polyketones), bioenergenetically derived from repeated condensation of acetyl coenzyme A via malonyl coenzyme A, in a process similar to fatty acid synthesis.Multigene Family: A set of genes descended by duplication and variation from some ancestral gene. Such genes may be clustered together on the same chromosome or dispersed on different chromosomes. Examples of multigene families include those that encode the hemoglobins, immunoglobulins, histocompatibility antigens, actins, tubulins, keratins, collagens, heat shock proteins, salivary glue proteins, chorion proteins, cuticle proteins, yolk proteins, and phaseolins, as well as histones, ribosomal RNA, and transfer RNA genes. The latter three are examples of reiterated genes, where hundreds of identical genes are present in a tandem array. (King & Stanfield, A Dictionary of Genetics, 4th ed)Tyrocidine: An antibiotic mixture produced by Bacillus brevis which may be separated into three components, tyrocidines A, B, and C. It is the major constituent (40-60 per cent) of tyrothricin, gramicidin accounting for the remaining 10-20 per cent active material. It is a topical antimicrobial agent, that is very toxic parenterally.Streptomyces: A genus of bacteria that form a nonfragmented aerial mycelium. Many species have been identified with some being pathogenic. This genus is responsible for producing a majority of the ANTI-BACTERIAL AGENTS of practical value.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Cucumis: A plant genus of the family CUCURBITACEAE, order Violales, subclass Dilleniidae best known for cucumber (CUCUMIS SATIVUS) and cantaloupe (CUCUMIS MELO). Watermelon is a different genus, CITRULLUS. Bitter melon may refer to MOMORDICA or this genus.Siloxanes: Silicon polymers that contain alternate silicon and oxygen atoms in linear or cyclic molecular structures.Dental Impression Materials: Substances used to create an impression, or negative reproduction, of the teeth and dental arches. These materials include dental plasters and cements, metallic oxide pastes, silicone base materials, or elastomeric materials.Dental Impression Technique: Procedure of producing an imprint or negative likeness of the teeth and/or edentulous areas. Impressions are made in plastic material which becomes hardened or set while in contact with the tissue. They are later filled with plaster of Paris or artificial stone to produce a facsimile of the oral structures present. Impressions may be made of a full complement of teeth, of areas where some teeth have been removed, or in a mouth from which all teeth have been extracted. (Illustrated Dictionary of Dentistry, 1982)Silicon Dioxide: Transparent, tasteless crystals found in nature as agate, amethyst, chalcedony, cristobalite, flint, sand, QUARTZ, and tridymite. The compound is insoluble in water or acids except hydrofluoric acid.Polymers: Compounds formed by the joining of smaller, usually repeating, units linked by covalent bonds. These compounds often form large macromolecules (e.g., BIOPOLYMERS; PLASTICS).PolyvinylsDimethylpolysiloxanes: Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.Ionic Liquids: Salts that melt below 100 C. Their low VOLATILIZATION can be an advantage over volatile organic solvents.Silicon: A trace element that constitutes about 27.6% of the earth's crust in the form of SILICON DIOXIDE. It does not occur free in nature. Silicon has the atomic symbol Si, atomic number 14, and atomic weight [28.084; 28.086].Silicates: The generic term for salts derived from silica or the silicic acids. They contain silicon, oxygen, and one or more metals, and may contain hydrogen. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th Ed)Magnesium Silicates: A generic term for a variety of compounds that contain silicon, oxygen, and magnesium, and may contain hydrogen. Examples include TALC and some kinds of ASBESTOS.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Silicate Cement: A relatively hard, translucent, restorative material used primarily in anterior teeth. (From Boucher's Clinical Dental Terminology, 4th ed, p50)Aluminum Silicates: Any of the numerous types of clay which contain varying proportions of Al2O3 and SiO2. They are made synthetically by heating aluminum fluoride at 1000-2000 degrees C with silica and water vapor. (From Hawley's Condensed Chemical Dictionary, 11th ed)Suspensions: Colloids with liquid continuous phase and solid dispersed phase; the term is used loosely also for solid-in-gas (AEROSOLS) and other colloidal systems; water-insoluble drugs may be given as suspensions.Calcium Compounds: Inorganic compounds that contain calcium as an integral part of the molecule.Lithium: An element in the alkali metals family. It has the atomic symbol Li, atomic number 3, and atomic weight [6.938; 6.997]. Salts of lithium are used in treating BIPOLAR DISORDER.Silicic Acid: A hydrated form of silicon dioxide. It is commonly used in the manufacture of TOOTHPASTES and as a stationary phase for CHROMATOGRAPHY.Metals, Alkaline Earth: Metals that constitute the group 2 (formerly group IIa) of the periodic table.Metals, Rare Earth: A group of elements that include SCANDIUM; YTTRIUM; and the LANTHANOID SERIES ELEMENTS. Historically, the rare earth metals got their name from the fact that they were never found in their pure elemental form, but as an oxide. In addition they were very difficult to purify. They are not truly rare and comprise about 25% of the metals in the earth's crust.Metals, Alkali: Metals that constitute group 1(formerly group Ia) of the periodic table. They are the most strongly electropositive of the metals. Note that HYDROGEN is not considered an alkali metal even though it falls under the group 1 heading in the periodic table.Metals: Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)Physician Assistants: Health professionals who practice medicine as members of a team with their supervising physicians. They deliver a broad range of medical and surgical services to diverse populations in rural and urban settings. Duties may include physical exams, diagnosis and treatment of disease, interpretation of tests, assist in surgery, and prescribe medications. (from http://www.aapa.orglabout-pas accessed 2114/2011)Dermatoglyphics: The study of the patterns of ridges of the skin of the fingers, palms, toes, and soles.DNA Fingerprinting: A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.Research: Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)Aquabirnavirus: A genus of RNA viruses in the family BIRNAVIRIDAE infecting fish, mollusks, and crustaceans. It is transmitted both vertically and horizontally with no known vectors. The natural hosts are salmonids and the type species is INFECTIOUS PANCREATIC NECROSIS VIRUS.Diving: An activity in which the organism plunges into water. It includes scuba and bell diving. Diving as natural behavior of animals goes here, as well as diving in decompression experiments with humans or animals.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.Health Services Research: The integration of epidemiologic, sociological, economic, and other analytic sciences in the study of health services. Health services research is usually concerned with relationships between need, demand, supply, use, and outcome of health services. The aim of the research is evaluation, particularly in terms of structure, process, output, and outcome. (From Last, Dictionary of Epidemiology, 2d ed)Biometric Identification: A method of differentiating individuals based on the analysis of qualitative or quantitative biological traits or patterns. This process which has applications in forensics and identity theft prevention includes DNA profiles or DNA fingerprints, hand fingerprints, automated facial recognition, iris scan, hand geometry, retinal scan, vascular patterns, automated voice pattern recognition, and ultrasound of fingers.Random Amplified Polymorphic DNA Technique: Technique that utilizes low-stringency polymerase chain reaction (PCR) amplification with single primers of arbitrary sequence to generate strain-specific arrays of anonymous DNA fragments. RAPD technique may be used to determine taxonomic identity, assess kinship relationships, analyze mixed genome samples, and create specific probes.

Novobiocin and related coumarins and depletion of heat shock protein 90-dependent signaling proteins. (1/101)

BACKGROUND: Heat shock protein 90 (Hsp90) interacts with and stabilizes several oncogenic protein kinases (e.g., p185(erbB2), p60(v-src), and Raf-1) and is required for the stability and dominant-negative function of mutated p53 protein. Two unrelated antibiotics, geldanamycin and radicicol, bind specifically to an atypical nucleotide-binding pocket of Hsp90, a site that shares homology with the adenosine triphosphate (ATP)-binding domain of bacterial DNA gyrase B. This interaction leads to destabilization of proteins that interact with Hsp90. Since the nucleotide-binding site of gyrase B is targeted by coumarin antibiotics (e.g., novobiocin), we investigated whether these drugs can also interact with Hsp90 and affect its activity. METHODS: We used immobilized novobiocin, geldanamycin, or radicicol to isolate either endogenous Hsp90 from cell lysates or Hsp90 deletion fragments translated in vitro. Effects of the coumarin antibiotics novobiocin, chlorobiocin, and coumermycin A1 on several proteins interacting with Hsp90 were assessed in vitro and in vivo. RESULTS: Hsp90 binding to immobilized novobiocin was competed by soluble coumarins and ATP but not by geldanamycin or radicicol. A carboxy-terminal Hsp90 fragment bound immobilized novobiocin but not immobilized geldanamycin, while a geldanamycin-binding amino-terminal fragment did not bind novobiocin. All three coumarins markedly reduced cellular levels of p185(erbB2), p60(v-src), Raf-1, and mutated p53. Furthermore, novobiocin reduced Raf-1 levels in the spleens of mice treated with the drug. CONCLUSIONS: These coumarin antibiotics, particularly novobiocin, represent a first-generation alternative to other Hsp90-targeting drugs that are not as well tolerated. Novobiocin's unique interaction with Hsp90 identifies an additional site on this protein amenable to pharmacologic interference with small molecules.  (+info)

Suppression of chromosome segregation defects of Escherichia coli muk mutants by mutations in topoisomerase I. (2/101)

Escherichia coli muk mutants are temperature-sensitive and produce anucleate cells. A spontaneously occurring mutation was found in a DeltamukBkan mutant strain that suppressed the temperature-sensitive phenotype and mapped in or near topA, the gene that encodes topoisomerase I. Previously characterized topA mutations, topA10 and topA66, were found to be general suppressors of muk mutants: they suppressed temperature sensitivity and anucleate cell production of cells containing null or point mutations in mukB and null mutations in mukE or mukF. The suppression correlated with excess negative supercoiling by DNA gyrase, and the gyrase inhibitor, coumermycin, reversed it. Defects in topA allow 99% of cell division events in muk null mutants to proceed without chromosome loss or loss of cell viability. This observation imposes important limitations on models for Muk activity and is consistent with a role for MukBEF in chromosome folding and DNA condensation.  (+info)

Membrane localization of Raf assists engagement of downstream effectors. (3/101)

We have previously described a small molecule-directed protein dimerization strategy, using coumermycin to juxtapose Raf fusion proteins containing the coumermycin-binding domain GyrB. Oligomerization of cytoplasmically localized Raf-GyrB fusion proteins leads to an increase in the kinase activity of both Raf and its substrate Mek. Surprisingly, more distal targets, such as Erk1 and Erk2, are not activated using this approach. Here we report that coumermycin-induced oligomerization of a membrane-localized Raf-GyrB fusion protein potently activated Erk1 and Erk2, up-regulated Fos protein levels, and induced expression of many immediate-early response genes. Thus, both membrane localization and oligomerization of Raf-GyrB are required to target Raf signals to downstream effectors. The ability to activate the entire Raf signal transduction cascade conditionally, using coumermycin-induced oligomerization, should prove useful for dissecting Raf-mediated effects on gene expression and cellular differentiation.  (+info)

Identification of the coumermycin A(1) biosynthetic gene cluster of Streptomyces rishiriensis DSM 40489. (4/101)

The biosynthetic gene cluster of the aminocoumarin antibiotic coumermycin A(1) was cloned by screening of a cosmid library of Streptomyces rishiriensis DSM 40489 with heterologous probes from a dTDP-glucose 4,6-dehydratase gene, involved in deoxysugar biosynthesis, and from the aminocoumarin resistance gyrase gene gyrB(r). Sequence analysis of a 30.8-kb region upstream of gyrB(r) revealed the presence of 28 complete open reading frames (ORFs). Fifteen of the identified ORFs showed, on average, 84% identity to corresponding ORFs in the biosynthetic gene cluster of novobiocin, another aminocoumarin antibiotic. Possible functions of 17 ORFs in the biosynthesis of coumermycin A(1) could be assigned by comparison with sequences in GenBank. Experimental proof for the function of the identified gene cluster was provided by an insertional gene inactivation experiment, which resulted in an abolishment of coumermycin A(1) production.  (+info)

Chimeric VEGFRs are activated by a small-molecule dimerizer and mediate downstream signalling cascades in endothelial cells. (5/101)

Despite much interest in vascular endothelial growth factor (VEGF) and its receptors (VEGFRs -1 and -2), VEGF-induced signalling cascades remain incompletely defined. Attempts to assign individual responses to a particular receptor have used either transfected cell lines, receptor-specific growth factors or antisense oligonucleotides. Such studies have attributed the majority of VEGF-induced responses to activation of VEGFR-2. As a consequence of poor growth factor-induced VEGFR-1 autophosphorylation however, observations from these studies may instead reflect the relative activation of the two receptors. We have generated novel chimeric VEGF receptors in which the dimerization domain of the B subunit of DNA gyrase is fused to the cytoplasmic domain of VEGFRs -1 and -2. When expressed in porcine aortic endothelial cells, both chimeric VEGFR-1 and -2 autophosphorylate in response to addition of the small-molecule dimerizing agent, coumermycin. Once activated, both receptors induce downstream signalling cascades, exemplified here by the activation of MAPK, PLCgamma and PKB/Akt. Furthermore, we demonstrate that the Y1175 residue of VEGFR-2 is essential for the activation of PLCgamma mediated by this chimeric receptor. In contrast to previous reports which show a limited ability of VEGFR-1 to mediate signalling cascades, we show that once sufficiently activated, VEGFR-1 signals in a similar manner to VEGFR-2 in endothelial cells.  (+info)

Brachyspira (Serpulina) hyodysenteriae gyrB mutants and interstrain transfer of coumermycin A(1) resistance. (6/101)

To further develop genetic techniques for the enteropathogen Brachyspira hyodysenteriae, the gyrB gene of this spirochete was isolated from a lambdaZAPII library of strain B204 genomic DNA and sequenced. The putative protein encoded by this gene exhibited up to 55% amino acid sequence identity with GyrB proteins of various bacterial species, including other spirochetes. B. hyodysenteriae coumermycin A(1)-resistant (Cn(r)) mutant strains, both spontaneous and UV induced, were isolated by plating B204 cells onto Trypticase soy blood agar plates containing 0.5 microg of coumermycin A(1)/ml. The coumermycin A(1) MICs were 25 to 100 microg/ml for the resistant strains and 0.1 to 0.25 microg/ml for strain B204. Four Cn(r) strains had single nucleotide changes in their gyrB genes, corresponding to GyrB amino acid changes of Gly(78) to Ser (two strains), Gly(78) to Cys, and Thr(166) to Ala. When Cn(r) strain 435A (Gly(78) to Ser) and Cm(r) Km(r) strain SH (DeltaflaA1::cat Deltanox::kan) were cultured together in brain heart infusion broth containing 10% (vol/vol) heat-treated (56 degrees C, 30 min) calf serum, cells resistant to chloramphenicol, coumermycin A(1), and kanamycin could be isolated from the cocultures after overnight incubation, but such cells could not be isolated from monocultures of either strain. Seven Cn(r) Km(r) Cm(r) strains were tested and were determined to have resistance genotypes of both strain 435A and strain SH. Cn(r) Km(r) Cm(r) cells could not be isolated when antiserum to the bacteriophage-like agent VSH-1 was added to cocultures, and the numbers of resistant cells increased fivefold when mitomycin C, an inducer of VSH-1 production, was added. These results indicate that coumermycin resistance associated with a gyrB mutation is a useful selection marker for monitoring gene exchange between B. hyodysenteriae cells. Gene transfer readily occurs between B. hyodysenteriae cells in broth culture, a finding with practical importance. VSH-1 is the likely mechanism for gene transfer.  (+info)

Complementation of a Treponema denticola flgE mutant with a novel coumermycin A1-resistant T. denticola shuttle vector system. (7/101)

By using the mutated gyrB gene from a spontaneous coumermycin A1-resistant Treponema denticola, an Escherichia coli-T. denticola shuttle vector that renders T. denticola resistant to coumermycin was constructed. The complete T. denticola flgE gene was cloned into the shuttle vector pKMCou, and the vector was transformed into the T. denticola ATCC 33520 flgE erythromycin-resistant knockout mutant HL210. The coumermycin-resistant transformants were motile and restored FlgE activity. This complementation system should prove useful in studying the virulence factors of T. denticola and uncultivatible pathogenic spirochetes.  (+info)

Promoter protection by a transcription factor acting as a local topological homeostat. (8/101)

Binding of the Escherichia coli global transcription factor FIS to the upstream activating sequence (UAS) of stable RNA promoters activates transcription on the outgrowth of cells from stationary phase. Paradoxically, while these promoters require negative supercoiling of DNA for optimal activity, FIS counteracts the increase of negative superhelical density by DNA gyrase. We demonstrate that binding of FIS at the UAS protects the rrnA P1 promoter from inactivation at suboptimal superhelical densities. This effect is correlated with FIS-dependent constraint of writhe and facilitated untwisting of promoter DNA. We infer that FIS maintains stable RNA transcription by stabilizing local writhe in the UAS. These results suggest a novel mechanism of transcriptional regulation by a transcription factor acting as a local topological homeostat.  (+info)

*Coumermycin A1

"Genetic engineering of antibiotic biosynthesis for the generation of new aminocoumarins". Biotechnology Advances. 27 (6): 1006- ...

*Clorobiocin

Heide, L. (2009). "Genetic engineering of antibiotic biosynthesis for the generation of new aminocoumarins". Biotechnology ...

*DNA gyrase

Two classes of antibiotics that inhibit gyrase are: The aminocoumarins (including novobiocin). Aminocoumarins work by ...

*Novobiocin

Aminocoumarins are very potent inhibitors of bacterial DNA gyrase and work by targeting the GyrB subunit of the enzyme involved ... The overlap of the coumarin and ATP-binding sites is consistent with aminocoumarins being competitive inhibitors of the ATPase ...

*List of MeSH codes (D03)

... aminocoumarins MeSH D03.438.150.446.139.500 --- novobiocin MeSH D03.438.150.446.280 --- chromonar MeSH D03.438.150.446.350 --- ... aminocoumarins MeSH D03.830.219.446.139.500 --- novobiocin MeSH D03.830.219.446.280 --- chromonar MeSH D03.830.219.446.350 --- ...
Interactions of several 7-aminocoumarins with human serum albumin (HSA) were studied by using fluorescence spectroscopic technique and modeling studies. There is a large change in fluorescence spectral parameters like intensity, emission maxima and anisotropy for all aminocoumarins. There were two binding sites for cou-1, 311 and a single binding site for other coumarins. The binding constant(s) are large for all coumarins reflective of a strong binding. These spectral studies show that structural variants at the third, fourth and seventh position affects binding. The probable location of these coumarins in domain Ii has been predicted based on modeling. The effect of structural modification on the efficiency of binding was obtained for various other coumarins, using modeling.. ...
The 5-methyl-2-pyrrolylcarbonyl moiety of the aminocoumarin antibiotics clorobiocin and coumermycin A1 is the key pharmacophore for targeting the ATP-binding site of GyrB for inhibition of the bacterial type-II topoisomerase DNA gyrase. During the late stage of clorobiocin and coumermycin A1 biosynthesis, the pyrrolyl-2-carboxyl group is transferred from the peptidyl carrier proteins Clo/CouN1 to the 3-hydroxyl of the 4-methoxy-L-noviosyl scaffold by the action of the acyltransferases Clo/CouN7. CouN1 and CouN7 have now been heterologously expressed and purified from Escherichia coli. The apo form of CouN1 is converted to the acyl-holo form by loading with pyrrolyl-2-carboxyl-S-pantetheinyl moieties from synthetic pyrrolyl- and 5-methylpyrrolyl-CoAs by the action of the phosphopantetheinyl transferase Sfp. CouN7 acts as an acyltransferase, moving the pyrrole acyl moieties from CouN1 to the noviose sugar of descarbamoylnovobiocin. When the 5-methylpyrrolyl-2-carboxyl-thioester of CouN1 is the
16907743] The small MbtH-like protein encoded by an internal gene of the balhimycin biosynthetic gene cluster is not required for glycopeptide production. (FEMS Microbiol Lett. , 2006 ...
ID V6KJ36_STRRC Unreviewed; 572 AA. AC V6KJ36; DT 19-FEB-2014, integrated into UniProtKB/TrEMBL. DT 19-FEB-2014, sequence version 1. DT 22-NOV-2017, entry version 21. DE SubName: Full=Chitinase {ECO:0000313,EMBL:EST32170.1}; GN ORFNames=M878_15530 {ECO:0000313,EMBL:EST32170.1}; OS Streptomyces roseochromogenus subsp. oscitans DS 12.976. OC Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae; OC Streptomyces. OX NCBI_TaxID=1352936 {ECO:0000313,EMBL:EST32170.1, ECO:0000313,Proteomes:UP000017984}; RN [1] {ECO:0000313,EMBL:EST32170.1, ECO:0000313,Proteomes:UP000017984} RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=DS 12.976 {ECO:0000313,EMBL:EST32170.1}; RX PubMed=24407645; RA Ruckert C., Kalinowski J., Heide L., Apel A.K.; RT "Draft Genome Sequence of Streptomyces roseochromogenes subsp. RT oscitans DS 12.976, Producer of the Aminocoumarin Antibiotic RT Clorobiocin."; RL Genome Announc. 2:e01147-13(2014). CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 18 family. CC ...
Inhibits the supercoiling activity of DNA gyrase. Acts by inhibiting DNA gyrase at an early step, prior to (or at the step of) binding of DNA by the gyrase. It protects cells against toxins that target DNA gyrase, by inhibiting activity of these toxins and reducing the formation of lethal double-strand breaks in the cell. Protects cells against the natural plasmid-encoded toxins microcin B17 (MccB17) and CcdB, and synthetic quinolones. Can also protect cells against alkylating agents that act independently of DNA gyrase, suggesting a more general role in protecting cells against DNA damage.
Abstract: A mutant of λ was isolated that grows in the Escherichia coli himAΔ/gyrB-him320 (Ts) double mutant at 42°C; conditions which are non-permissive for wild-type λ growth. The responsible mutation, ohm1 , alters the 40th codon of the Nul reading frame. The Nul and A gene products comprise the terminase protein which cleaves concatameric DNA into unit-length phage genomes during DNA packaging. The Nul-ohm1 gene product acts in trans to support λ growth in the double himA/gyrB mutant, and λ cos154 growth in the single himA mutant. The observation that an alteration in Nul suppresses the inhibition of growth in the double himA/gyrB mutant implicates DNA gyrase, as well as integration host factor, in the DNA: protein interactions that occur at the initiation of packaging ...
A 990581 was a 2-pyridone novel DNA gyrase inhibitor with potent activity against both Gram-positive and Gram-negative resistant bacteria including anaerobes.
The role of MbtH-like proteins in nonribosomal peptides synthetase (NRPS) assembly-lines: Tools for biosynthesis/bioengineering of novel antibiotics.
The intramolecular neighboring group participation of the amino group of 7-aminocoumarin moiety to phenylboronic acid gave fluorescence intensity and spectral changes upon saccharide binding which could be used in fluorescence mapping of saccharides in biological cells.. ...
Hi Ronan, for pBR322 I use 1 to 15 ug/ml chloroquin in gel and running buffer. Topoisomers of pBR isolated from E. coli are clearly separated at 10 ug/ml chloroquin, except when the DNA is extremely relaxed (like when you add a gyrase inhibitor), then you need to add less chloroquin. Extremely supercoiled DNA needs more chloroquin to pull the bands apart. but not too much, or youll get positively writhed plasmids on top of the negative ones. Good luck, Rogier * Sent from RemarQ http://www.remarq.com The Internets Discussion Network * The fastest and easiest way to search and participate in Usenet - Free ...
Glycosylated analogues of novobiocin, discovered using a broad library of enzymes, have 100-fold improved activity against breast, brain, pancreatic, lung and ovarian cancers and ablated associated off-target activity leading to an up to 2.7 × 10(4) fold increase in selectivity.. ...
The MSRRTC is funded by the U.S. Department of Education, National Institute for Disability and Rehabilitation Research under cooperative agreement H133B080025, from 2008-2013. The information developed by the MSRRTC does not necessarily represent the policy of the Department of Education, and you should not assume endorsement by the Federal Government (Edgar, 75.620 (b)). ...
4GGL: Pyrrolopyrimidine inhibitors of dna gyrase b and topoisomerase iv, part i: structure guided discovery and optimization of dual targeting agents with potent, broad-spectrum enzymatic activity
MbtH-like proteins are a family of small proteins encoded by genes found in many, but not all, non-ribosomal peptide synthetase-encoding gene clusters that direct the biosynthesis of peptide antibiotics and siderophores. Studies published to date have not elucidated the function of MbtH-like proteins, nor have they clarified whether they are required for metabolite biosynthesis. Here it is shown that only one of two genes (cdaX or cchK) encoding MbtH-like proteins in Streptomyces coelicolor is required for biosynthesis of the peptide siderophore coelichelin and the calcium-dependent peptide antibiotic (CDA). The cdaX and cchK genes can functionally complement each other in trans, suggesting that CdaX and CchK can cross-talk with the coelichelin and CDA biosynthetic pathways, respectively. Transcriptional analyses of wild-type S. coelicolor and a double cchK/cdaX replacement mutant indicate that CchK and CdaX may not be involved in transcriptional regulation of coelichelin and CDA biosynthetic ...
Abstract DNA gyrase is a type II topoisomerase that can introduce negative supercoils into DNA at the expense of ATP hydrolysis. It is essential in all bacteria but absent from hig..
4HY1: Pyrrolopyrimidine inhibitors of DNA gyrase B (GyrB) and topoisomerase IV (ParE). Part I: Structure guided discovery and optimization of dual targeting agents with potent, broad-spectrum enzymatic activity.
DNA gyrase is a bacterial enzyme that catalyzes the ATP-dependent negative supercoiling of double-stranded, closed-circular DNA, according to the Critical Review of Biochemical and Molecular Biology....
Definition of DNA reverse gyrase with photos and pictures, translations, sample usage, and additional links for more information.
CL-promoted DNA cleavage mediated by gyrase occurs at specific sites and is stimulated by ATP. The 290-bp S fragment (from the S. pneumoniae parE gene) 33P-labe
Novobiocin binds to DNA gyrase and blocks adenosine triphosphatase (ATPase) activity. Novobiocin sodium is an antibiotic compound derived from Streptomyces nive ...
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We have analysed the DNA cleavage reaction of DNA gyrase using oligonucleotides annealed to a singlestranded M13 derivative containing a preferred gyrase cleavage site. We find that gyrase can cleave duplexes down to ∼20 bp in size in the presence of the quinolone drugs ciprofloxacin and oxolinic acid. Ciprofloxacin shows a variation in its site specificity with an apparent preference for G bases adjacent to the cleavage sites, whereas oxolinic acid stimulates cleavage predominantly at the previously determined site. With either drug, cleavage will not occur within 6 bases from the end of a DNA duplex or a nick. We suggest that cleavage site specificity with short DNA duplexes is determined by drug-DNA interactions whereas with longer fragments the positioning effect of the DNA wrap around gyrase prescribes the site of cleavage ...
Infections caused by more than one type of organisms are called as mixed infections and the best therapeutic option for their treatment is to combine two different drugs with different mechanism of action. O2 is a combination of ofloxacin and ornidazole. Ofloxacin is second generation fluoro-quinolone antibiotic which inhibits bacterial DNA gyrase enzyme, interfering in the synthesis of DNA in the bacteria and shows bactericidal action. Ornidazole is a newer nitroimidazoles with superior efficacy and longer duration of action. It kills susceptible microorganisms by interfering with DNA functioning. Hence combination of these two drugs shown higher efficacy, broad antimicrobial spectrum, least incidence of side effects and both are well tolerated ...
DNA gyrase is involved in DNA replication, which happens when bacteria reproduce. A family of antibiotics called fluoroquinolones target this enzyme, killing the bacteria that cause infections such as cholera, anthrax, gonorrhoea, meningitis, E. coli and MRSA. The researchers found that when MurI binds to DNA gyrase, it takes gyrase away from substrate DNA. Because of this, antibiotics cannot bind and stop it from working, so the bacteria become resistant to treatment.. "Our findings suggest that MurI has a role in safeguarding DNA gyrase from attack by antibiotics," said Professor Nagaraja. "The moonlighting activity of MurI seems to have evolved more recently to protect and control DNA gyrase.". MurI is not alone in its moonlighting activities; other bacterial enzymes and proteins also carry out different functions. But why has this ability evolved? "Multifunctional proteins are mostly common enzymes that have acquired different roles over the long period of their existence," said Professor ...

Patente US3965024 - Washing agent compositions and washing assistant composition containing ... - Google PatentesPatente US3965024 - Washing agent compositions and washing assistant composition containing ... - Google Patentes

The polyamide brighteners further include aliphatically or aromatically substituted aminocoumarins, such as 4-methyl-7- ...
more infohttp://www.google.es/patents/US3965024?dq=flatulence

Photochemical reactions of 7-aminocoumarins. 10. Reaction of 3-iodo-4-methyl-7-diethylaminocoumarin with heteroaromatic...Photochemical reactions of 7-aminocoumarins. 10. Reaction of 3-iodo-4-methyl-7-diethylaminocoumarin with heteroaromatic...

Photochemical reactions of 7-aminocoumarins. 10. Reaction of 3-iodo-4-methyl-7-diethylaminocoumarin with heteroaromatic ... and benzimidazole results in the formation of a series of 3-hetaryl-7-aminocoumarins. The spectral luminescence characteristics ...
more infohttps://link.springer.com/article/10.1007/BF00476972

Antioxidant activity and protective role on protein glycation of synthetic aminocoumarinsAntioxidant activity and protective role on protein glycation of synthetic aminocoumarins

We showed that the aminocoumarins profoundly prevent the structural changes caused by D-glucose, keeping the protein molecule ... Background: Synthesized aminocoumarins are heterocyclic compounds possessing potential for the treatment of insulin-dependent ...
more infohttps://scielo.conicyt.cl/scielo.php?script=sci_arttext&pid=S0717-34582016000600007&lng=pt&nrm=iso&tlng=en

Complex Enzymes In Microbial Natural Product Biosynthesis Part B Polyketides Aminocoumarins And Carbohydrates 2009Complex Enzymes In Microbial Natural Product Biosynthesis Part B Polyketides Aminocoumarins And Carbohydrates 2009

... by Freda ... Complex Enzymes In Microbial Natural Product Biosynthesis Part B Polyketides Aminocoumarins And Carbohydrates 2009. Mickey ... Alongside David works his complex enzymes in microbial natural product biosynthesis part b polyketides aminocoumarins and ... Responding a complex enzymes in microbial natural product biosynthesis part b polyketides aminocoumarins problem AND BOOK ...
more infohttp://subflux.com/blog/images/rubric/book/complex-enzymes-in-microbial-natural-product-biosynthesis-part-b-polyketides-aminocoumarins-and-carbohydrates-2009/

GAO-11-801, Antibiotic Resistance: Agencies Have Made Limited Progress Addressing Antibiotic Use in AnimalsGAO-11-801, Antibiotic Resistance: Agencies Have Made Limited Progress Addressing Antibiotic Use in Animals

Antimicrobial class: Aminocoumarins, Glycolipids, Quinoxalines combined; Annual totals (kilograms of active ingredient): ...
more infohttps://www.gao.gov/assets/330/323097.html

Patente WO1993007086A1 - Bleaching compositions - Google PatentesPatente WO1993007086A1 - Bleaching compositions - Google Patentes

... and the y-amino- coumarins. Specific examples of these brighteners include 4-methyl-7-diethylamino coumarin; l,2-bis(- ...
more infohttp://www.google.es/patents/WO1993007086A1?cl=en

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Complex Enzymes in Microbial Natural Product Biosynthesis, Part B: Polyketides, Aminocoumarins and Carbohydr Academic Press ...
more infohttps://books.rakuten.co.jp/search/nm?f=A&sitem=heinz+duthel&y=&x=&mt=0&o=0&cy=0&won=0&h=30&g=101&e=0&v=2&spv=2&s=5&sv=30

US6310025B1 - Laundry pretreatment process and bleaching compositions 
        - Google PatentsUS6310025B1 - Laundry pretreatment process and bleaching compositions - Google Patents

... and the aminocoumarins. Specific examples of these brighteners include 4-methyl-7-diethyl- amino coumarin; 1,2-bis(- ...
more infohttps://patents.google.com/patent/US6310025B1/en

CN1195833C - Cleaning products which uses sonic or ultrasonic waves 
        - Google PatentsCN1195833C - Cleaning products which uses sonic or ultrasonic waves - Google Patents

... and the aminocoumarins. 这些增白剂的具体例子包括:4-甲基-7-二乙氨基香豆素;1,2-二(-venz咪唑-2-基)亚乙基;1,3-二苯基-环戊四唑啉(phrazoline);2,5-二
more infohttps://patents.google.com/patent/CN1195833C/en

Patent US3922435 - Heat transfer label - Google PatentsPatent US3922435 - Heat transfer label - Google Patents

2lkyl-7dialkyl-amino coumarins, benzidine sulfone disulfonic acid, diphenyl pyrazoline. Any of these compounds are known and ... Also, the triazines, the diazines, the imidazoles, the oxazoles, the coumarins, the aminocoumarins, the sulfone sulfonic acids ...
more infohttp://www.google.com/patents/US3922435?dq=6978253

New way to fight drug-resistant bacteria - UPI.comNew way to fight drug-resistant bacteria - UPI.com

By modifying aminocoumarins, the researchers said they hope to develop more effective inhibitors, turning them into more potent ... Aminocoumarins are inhibitors of bacterial enzymes that untwist and unknot DNA. Without these enzymes, bacteria cannot ... The researchers said they can generate potentially hundreds of variants of antibiotics called aminocoumarins. ...
more infohttps://www.upi.com/Science_News/2004/08/25/New-way-to-fight-drug-resistant-bacteria/UPI-36611093486500/

What is Fluorescence Spectroscopy? - HORIBAWhat is Fluorescence Spectroscopy? - HORIBA

Organic dyes (fluorescein, rhodamine, N-aminocoumarins and derivatives of these). *Rare earth elements (lanthanides) ...
more infohttps://www.horiba.com/en_en/technology/measurement-and-control-techniques/spectroscopy/what-is-fluorescence-spectroscopy/

JoVE | Peer Reviewed Scientific Video Journal - Methods and ProtocolsJoVE | Peer Reviewed Scientific Video Journal - Methods and Protocols

Coumabiocins A-F, aminocoumarins from an organic extract of Streptomyces sp. L-4-4. ... led to the isolation of six new aminocoumarins, coumabiocins A-F (1-6), along with two known compounds, novobiocin (7) and ...
more infohttps://www.jove.com/visualize?author=Chee-Jen%20Chang%20

Microbiological indoor air quality in an office building in Gliwice, Poland: analysis of the case study | SpringerLinkMicrobiological indoor air quality in an office building in Gliwice, Poland: analysis of the case study | SpringerLink

Various groups, e.g., aminocoumarins, carbapenems, cephalosporins, glycopeptides, macrolides, penicillins, quinolones/ ...
more infohttps://link.springer.com/article/10.1007%2Fs11869-018-0579-z

Frontiers | The Transcriptome of Streptococcus pneumoniae Induced by Local and Global Changes in Supercoiling | MicrobiologyFrontiers | The Transcriptome of Streptococcus pneumoniae Induced by Local and Global Changes in Supercoiling | Microbiology

2014). Altering gene expression by aminocoumarins: the role of DNA supercoiling in Staphylococcus aureus. BMC Genomics 15:291. ...
more infohttps://www.frontiersin.org/articles/10.3389/fmicb.2017.01447/full

Toxins  | Free Full-Text | Phylogenetic Study of Polyketide Synthases and Nonribosomal Peptide Synthetases Involved in the...Toxins | Free Full-Text | Phylogenetic Study of Polyketide Synthases and Nonribosomal Peptide Synthetases Involved in the...

Cox, R.J.; Simpson, T.J. Complex enzymes in microbial natural product biosynthesis, part B: Polyketides, aminocoumarins and ...
more infohttp://www.mdpi.com/2072-6651/5/4/717/htm

Patent US4396524 - Preparation of polysiloxane block polymers and their use as foam inhibitors - Google PatentsPatent US4396524 - Preparation of polysiloxane block polymers and their use as foam inhibitors - Google Patents

Also suitable are substituted aminocoumarins, for example, the 4-methyl-7-dimethyl-amino or the 4-methyl-7-diethylaminocoumarin ...
more infohttp://www.google.com/patents/US4396524?dq=5,987,610

Patent US4737306 - Layered silicates of limited swelling power, a process for their production ... - Google PatentsPatent US4737306 - Layered silicates of limited swelling power, a process for their production ... - Google Patents

Other suitable polyamide brighteners are substituted aminocoumarins, for example 4-methyl-7-dimethylamino or 4-methyl-7- ...
more infohttp://www.google.com.au/patents/US4737306

Coumermycin A1 - WikipediaCoumermycin A1 - Wikipedia

"Genetic engineering of antibiotic biosynthesis for the generation of new aminocoumarins". Biotechnology Advances. 27 (6): 1006- ...
more infohttps://en.wikipedia.org/wiki/Coumermycin_A1

Clorobiocin - WikipediaClorobiocin - Wikipedia

Heide, L. (2009). "Genetic engineering of antibiotic biosynthesis for the generation of new aminocoumarins". Biotechnology ...
more infohttps://en.wikipedia.org/wiki/Clorobiocin

Marine Drugs  | Free Full-Text | Biogenetic Relationships of Bioactive Sponge Merotriterpenoids | HTMLMarine Drugs | Free Full-Text | Biogenetic Relationships of Bioactive Sponge Merotriterpenoids | HTML

Saleh, O.; Haagen, Y.; Seeger, K.; Heide, L. Prenyl transfer to aromatic substrates in the biosynthesis of aminocoumarins, ...
more infohttp://www.mdpi.com/1660-3397/15/9/285/htm

Novobiocin - WikipediaNovobiocin - Wikipedia

Aminocoumarins are very potent inhibitors of bacterial DNA gyrase and work by targeting the GyrB subunit of the enzyme involved ... The overlap of the coumarin and ATP-binding sites is consistent with aminocoumarins being competitive inhibitors of the ATPase ...
more infohttps://en.wikipedia.org/wiki/Novobiocin

Browse by Subjects - Zurich Open Repository and ArchiveBrowse by Subjects - Zurich Open Repository and Archive

A hybrid TDDFT/MM investigation of the optical properties of aminocoumarins in water and acetonitrile solution. Physical ...
more infohttp://www.zora.uzh.ch/view/subjectsnew/10261.refereed_set.html
  • Fluoroquinolones (the DNA complex) and aminocoumarins (the ATP site) target these enzymes. (blogspot.com)
  • The overlap of the coumarin and ATP-binding sites is consistent with aminocoumarins being competitive inhibitors of the ATPase activity. (wikipedia.org)