PMID(sorted descending)
a soluble mitochondrial protein increases the voltage dependence of the mitochondrial channel, vdac.a soluble protein isolated from mitochondria has been found to modulate the voltage-dependent properties of the mitochondrial outer membrane channel, vdac. this protein, called the vdac modulator, was first found in neurospora crassa and then discovered in species from other eukaryotic kingdoms. the modulator-containing fraction (at a crude protein concentration of 20 micrograms/ml) increases the voltage dependence of vdac channels over 2-3-fold. at higher protein concentrations (50-100 microgra ...19921380504
x-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of neurospora crassa. x. heterozygous effects of multilocus deletion mutations of genotype ad-3a or ad-3b.previous studies on x-ray-induced irreparable adenine-3 mutations (designated [ad-3]ir), induced in heterokaryon 12 of neurospora crassa, demonstrated that they were not recessive and exhibited heterozygous effects in terms of markedly reduced linear growth rates (de serres, 1965). complementation tests with a series of tester strains carrying multilocus deletion mutations in the ad-3 and immediately adjacent genetic regions demonstrated that x-ray-induced irreparable mutations map, in the main ...19921373846
import of cytochrome c heme lyase into mitochondria: a novel pathway into the intermembrane space.cytochrome c heme lyase (cchl) catalyses the covalent attachment of the heme group to apocytochrome c during its import into mitochondria. the enzyme is membrane-associated and is located within the intermembrane space. the precursor of cchl synthesized in vitro was efficiently translocated into isolated mitochondria from neurospora crassa. the imported cchl, like the native protein, was correctly localized to the intermembrane space, where it was membrane-bound. as with the majority of mitochon ...19921371459
an inducible gene expression system for neurospora crassa.neurospora crassa acetyl coa synthetase is highly induced when the growing mycelium is transferred from sucrose- to acetate-based medium. the inducible promoter of this gene has been isolated and used to control the expression of glutamate dehydrogenase. transformants containing this expression cassette show gdh levels up to 25 times higher than the nontransformed host strain. this expression cassette will form the basis of a system of heterologous gene expression.19911369451
cellulase production by neurospora crassa: purification and characterization of cellulolytic studies on cellulase production by the cell-1 mutant of neurospora crassa, eight enzymes (three exoglucanases, four endoglucanases, and one beta-glucosidase) were identified and characterized by gel filtration, ion exchange chromatography, and chromatofocusing. after purification, each of the proteins ran as a single band in polyacrylamide gel electrophoresis, using both native and denaturing gels. the molecular weights of the proteins were found to be between 70,000 and 22,000 daltons, and a ...19901368541
cloning and heterologous expression of the penicillin biosynthetic gene cluster from penicillum chrysogenum.a cosmid clone containing the putative penicillin biosynthetic gene cluster from penicillium chrysogenum was used to transform the related filamentous fungi neurospora crassa and aspergillus niger, which do not produce beta-lactam antibiotics. both of the transformed hosts contained intact p. chrysogenum dna derived from the cosmid clone and produced authentic penicillin v. assays of penicillin biosynthetic enzyme activity additionally demonstrated that they possessed delta-(l-alpha-amino-adipyl ...19901368505
integrative transformation of the ascomycete podospora anserina: identification of the mating-type locus on chromosome vii of electrophoretically separated chromosomes.protoplasts of wild-type strain s and a long-lived extrachromosomal mutant (al2) of the ascomycete podospora anserina were transformed using a plasmid (pan7-1) which contains the hygromycin b phosphotransferase gene (hph) of escherichia coli under the control of aspergillus nidulans regulatory sequences. after optimizing the transformation procedure, transformation efficiencies of 15-21 transformants/micrograms plasmid dna were obtained. using a second selectable vector (pbt3), which contains th ...19911367277
hsp80 of neurospora crassa: cdna cloning, gene mapping, and studies of mrna accumulation under stress.using mrna isolated from neurospora crassa mycelium, grown for 14 h at normal growth temperature of 28 degrees c, and heat shocked for 1 h at 48 degrees c, a cdna library was prepared in the expression vector lambda gt11. following immunoscreening of this library with a polyclonal antiserum raised against a 80-kilodalton heat-shock protein (hsp80), cdna clones containing 1.1- and 1.4-kilobase inserts were selected. analysis of the partial nucleotide sequence and the deduced amino acid sequence o ...19921363716
cloning and disruption of a gene required for growth on acetate but not on ethanol: the acetyl-coenzyme a synthetase gene of saccharomyces cerevisiae.a dna fragment of saccharomyces cerevisiae with high homology to the acetyl-coenzyme a (acetyl-coa) synthetase genes of aspergillus nidulans and neurospora crassa has been cloned, sequenced and mapped to chromosome i. it contains an open reading frame of 2139 nucleotides, encoding a predicted gene product of 79.2 kda. in contrast to its ascomycete homologs, there are no introns in the coding sequence. the first atg codon of the open reading frame is in an unusual context for a translational star ...19921363452
truffle melanogenesis: correlation with reproductive differentiation and ascocarp ripening.the present work uses histochemical techniques to investigate the correlation between reproductive differentiation and age of truffles (tuber aestivum and tuber melanosporum) with melanin synthesis. the dopa oxidase and tyrosine hydroxylase activities of tyrosinase have been localized within the ascocarp and melanin localization was performed by the schmorl's reaction. a true tyrosinase is present in truffles, able to oxidize both l-tyrosine and l-dopa. the tyrosinase activity is on in the young ...19921363133
isolation and characterization of new fluoroacetate resistant/acetate non-utilizing mutants of neurospora crassa.sixty-two mutants of the filamentous fungus neurospora crassa were isolated on the basis of resistance to the antimetabolite fluoroacetate. of these, 14 were unable to use acetate as sole carbon source (acetate non-utilizers, acu) and were the subject of further genetic and biochemical analysis. these mutants fell into four complementation groups, three of which did not complement any known acu mutants. mutants of complementation group 3 failed to complement acu-8, demonstrated similar phenotypi ...19921362582
the ncypt1 gene from neurospora crassa is located on chromosome 2: molecular cloning and structural analysis.small gtp-binding proteins are encoded by ras-like genes and play a central role in cell differentiation and membrane vesicle transport. by screening genomic and cdna libraries of the ascomycete fungus neurospora crassa with zmypt genes from zea mays we have isolated a member of the ypt gene family, ncypt1. the gene resides on a 4 kb fragment of genomic dna and contains four introns, which interrupt the coding sequence of a protein of 203 amino acid residues. the ncytp1 gene was assigned to a si ...19921361212
structural relationship between the hexameric and tetrameric family of glutamate dehydrogenases.the family of glutamate dehydrogenases include a group of hexameric oligomers with a subunit m(r) of around 50,000, which are closely related in amino acid sequence and a smaller group of tetrameric oligomers based on a much larger subunit with m(r) 115,000. sequence comparisons have indicated a low level of similarity between the c-terminal portion of the tetrameric enzymes and a substantial region of the polypeptide chain for the more widespread hexameric glutamate dehydrogenases. in the light ...19921358610
mitochondrial dna of schizophyllum commune: restriction map, genetic map, and mode of inheritance.mitochondrial dna (mtdna) found in the basidiomycete schizophyllum commune (strain 4-40) is a circular molecule 49.75 kbp in length. a physical map containing 61 restriction sites revealed no repeat structures. cloned genes from neurospora crassa, aspergillus nidulans, and saccharomyces cerevisiae were used in southern hybridizations to locate nine mitochondrial genes, including a possible pseudogene of atpase 9, on the restriction map. a probe from a functional atpase 9 gene identified homologo ...19921358467
an acetate-sensitive mutant of neurospora crassa deficient in acetyl-coa hydrolase.the predicted amino acid sequence of the product of the acetate-inducible acu-8 gene of neurospora crassa, previously of unknown function, has close homology to the recently published sequence of saccharomyces cerevisiae acetyl-coa hydrolase. an acu-8 mutant strain, previously characterized as acetate non-utilizing, shows strong growth-inhibition by acetate, but will use it as carbon source at low concentrations. the mutant was shown to be deficient in acetyl-coa hydrolase and to accumulate acet ...19921357077
sexual development genes of neurospora crassa.the filamentous fungus neurospora crassa undergoes a complex program of sexual development to form a fruiting body composed of several kinds of specialized tissue. subtractive hybridization was used to isolate genes that are expressed preferentially during this sexual phase. many such sexual development (sdv) genes were identified in a cosmid library of neurospora genomic dna. fourteen of the sdv genes were subcloned, and their expression in mutant strains and under crossing and vegetative growt ...19921356883
the acu-1 gene of coprinus cinereus is a regulatory gene required for induction of acetate utilisation enzymes.we have isolated a gene from coprinus cinereus which cross-hybridises to the faca and acu-5 genes of aspergillus nidulans and neurospora crassa, respectively. these genes encode acetyl-coa synthetase, an enzyme which is inducible by acetate and required for growth on acetate as sole carbon source. we have designated the c. cinereus gene acs-1 and have used transformation to demonstrate its functional homology to the ascomycete genes by complementation of an n. crassa acu-5 mutation. the acs-1 ge ...19921354839
molecular cloning of a gene (cfp) encoding the cytoplasmic filament protein p59nc and its genetic relationship to the snowflake locus of neurospora crassa.p59nc is a 59-kd polypeptide associated with 8-10-nm diameter cellular filaments in normal neurospora crassa strains. abnormally sized and shaped bundles of these structures are present in n. crassa strains carrying mutations at the locus sn (snowflake). by using molecular cloning and restriction fragment length polymorphism (rflp) segregation analysis strategies we show here that sn is not the genetic locus of p59nc. several p59nc cdnas were cloned from a n. crassa lambda gt11 library after imm ...19921352758
structures of the genes encoding the alpha and beta subunits of the neurospora crassa mitochondrial atp synthase.we have isolated and sequenced cdna and genomic clones encoding the alpha and beta subunits of the neurospora crassa atp synthase. the genes are not linked to each other: atp-1(alpha) maps to either linkage group i or v, and atp-2(beta) lies on linkage group ii. the two genes resemble each other in having a large number of introns, five in atp-1 and seven in atp-2, mostly positioned near their 5' ends and varying in length from 60-332 bp. the coding regions of both genes have a high g+c content ...19921351018
[in situ studies of myoinositol-1-p synthase in wild and inos- strains of neurospora crassa].the biosynthetic pathway for myo-inositol consist of two enzymatic steps: first, the cycloaldolization of glucose-6p to l-myo-inositol-ip followed by its hydrolysis to form free myo-inositol. the former reaction is catalyzed by myo-inositol-ip synthase (mips) while, a phosphatase is responsible for the hydrolysis step. depending on its degree of purification and storage age, mips activity us to be, from partial to fully, dependent on added nad. therefore, we decided to study the kinetic properti ...20131345122
phospholipid content of untreated and insulin treated cells of neurospora crassa (wall-less strain).phosphatidylcholine (51.2%) and phosphatidyl-ethanolamine (38.3%) are the most abundant phospholipids in the wall-less strain of neurospora crassa. insulin treatment exerted no change on the amount of phosphoinositides, although some previous results proved the existence of specific insulin receptors and specific effect of insulin on glucose metabolism in these cells. long (20 h) treatment with insulin also failed to cause biologically significant changes.19921343935
the pho-2a mutant of neurospora crassa which is deficient in pi-repressible alkaline phosphatase (ec is also defective in pi-repressible acid phosphatase (ec the mycelial pi-repressible acid phosphatase presented p-nitrophenylphosphatase activity with negative cooperativity and michaelian behavior when synthesized by the wild-type and pho-2a mutant strains of neurospora crassa, respectively. 2. the major acid phosphatase present in cell extracts of the pho-2a mutant of n. crassa grown in low pi medium is more thermolabile (t1/2 = 4 min at 54 degrees c, ph 5.4) than that of the wild strain (stable for at least 80 min at 54 degrees c, ph 5.4). 3. th ...19921342219
accumulation of the pre-assembled membrane arm of nadh:ubiquinone oxidoreductase in mitochondria of manganese-limited grown neurospora crassa.the nadh:ubiquinone oxidoreductase (complex i) of mitochondria is constructed from two arms arranged perpendicular to each other. the peripheral arm protruding into the matrix contains the proximal section of the electron pathway, and the membrane arm with all mitochondrially encoded subunits contains the distal section of the electron pathway. when neurospora crassa is grown under manganese limitation the formation of the peripheral arm is disturbed, but the membrane arm containing the iron-sul ...19921330699
increase in superoxide production by heat-shocked cells of neurospora crassa, demonstrated by a fluorometric assay.1. increase in superoxide production by heat-shocked cells of neurospora crassa was demonstrated by a fluorometric assay. 2. a sensitive fluorometric assay for the estimation of superoxide anion radical--based on the liberation of 4-methylumbelliferone from 4-methyl-beta-d-umbelliferyl glucopyranoside--is described. 3. using this system the level of superoxide in the medium of heat-shocked neurospora crassa cells was found to be consistently higher, in comparison with that of non-shocked cells, ...19921327889
identification of the mitochondrial receptor complex in saccharomyces cerevisiae.mitochondrial protein import involves the recognition of preproteins by receptors and their subsequent translocation across the outer membrane. in neurospora crassa, the two import receptors, mom19 and mom72, were found in a complex with the general insertion protein, gip (formed by mom7, mom8, mom30 and mom38) and mom22. we isolated a complex out of s. cerevisiae mitochondria consisting of mom38/isp42, the receptor mom72, and five new yeast proteins, the putative equivalents of n. crassa mom7, ...19921327874
non-linear inhibition curves for tight-binding inhibitors of dimeric ubiquinol-cytochrome c oxidoreductases. evidence for rapid inhibitor mobility.steady-state electron flow through and electron delivery into isolated dimeric bc1 complex (ubiquinol--cytochrome c oxidoreductase) from neurospora crassa and beef heart mitochondria were studied in the presence of increasing concentrations of antimycin a, funiculosin and/or myxothiazol. parabolic or linear inhibition curves were obtained, depending upon the different quinols and inhibitors that were used. linear curves occur when the inhibitor directly affects the rate-determining step. the mos ...19921325904
purification and characterization of a mammalian endo-exonuclease has been purified from cultured monkey (cv-1) cells. the enzyme which was purified to near homogeneity to be a 65 kda monomeric protein. the single-strand dnase activity is endonucleolytic and nonprocessive, whereas the double-strand dnase activity is exonucleolytic and processive. the enzyme was also found to have rnase activity using poly-ra as substrate. the ph optimum for ss-dnase is 8 and for ds-dnase it is 7.5. both dnase activities require a divalent metal ion (mg2+, m ...19921324480
a protein required for rna processing and splicing in neurospora mitochondria is related to gene products involved in cell cycle protein phosphatase functions.the neurospora crassa cyt-4 mutants have pleiotropic defects in mitochondrial rna splicing, 5' and 3' end processing, and rna turnover. here, we show that the cyt-4+ gene encodes a 120-kda protein with significant similarity to the ssd1/srk1 protein of saccharomyces cerevisiae and the dis3 protein of schizosaccharomyces pombe, which have been implicated in protein phosphatase functions that regulate cell cycle and mitotic chromosome segregation. the cyt-4 protein is present in mitochondria and i ...19921311848
ca(2+)-dependent ubiquitination of calmodulin in yeast.recently we were able to show that calmodulin from vertebrates, plants (spinach) and the mold neurospora crassa can be covalently conjugated to ubiquitin in a ca(2+)-dependent manner by ubiquityl-calmodulin synthetase (ucam-synthetase) from mammalian sources [r. ziegenhagen and h.p. jennissen (1990) febs lett. 273, 253-256]. it was therefore of high interest to investigate whether this covalent modification of calmodulin also occurs in one of the simplest eukaryotes, the unicellular saccharomyce ...19921309706
induction and intracellular localization of the 80-kilodalton heat-shock protein of neurospora crassa.the most abundant heat-shock protein of neurospora crassa is a multimeric glycoprotein of 80-kilodaltons (i.e., hsp80), induced strongly by hyperthermia and at a lower level by sodium arsenite, ethanol, and carbon source depletion. immunoelectron microscopy, using indirect immunogold labelling demonstrated that hsp80 was undetectable in mycelium cultured at the normal growth temperature of 28 degrees c, but it appeared rapidly following the commencement of heat-shock treatment at 48 degrees c. h ...19921299272
nucleolar dense granules in cytochalasin-treated conidia of neurospora crassa. 19921288898
introduction of interrupted secondary structure in supercoiled dna as a function of superhelix density: consideration of hairpin structures in superhelical dna.pm2 dna was prepared with different superhelical densities (sigma) in order to examine the relationship betweenn supercoiling and the occurrence of a region(s) of unpaired bases in this dna. a previous study showed that ch3hgoh reacts with native superhelical pm2 dna more rapidly than the nicked form ii. this evaluation of binding, monitored through the change of sedimentation velocity, was repeated on pm2 dna i with different superhelical densities. early binding is detected by an increase in s ...19761255870
regulation of the activity of microbial kynureninase by transamination of the enzyme-bound coenzyme.kynureninase was purified to homogeneity from the extracts of pseudomonas marginalis and neurospora crassa. the active kynureninase containing pyridoxal 5'-phosphate transaminates with l-ornithine or l-alanine to form the inactive pyridoxamine 5'-phosphate form of enzyme and delta1-pyrroline-2-carboxylate or pyruvate. this inactive enzyme transaminates with pyruvate to restore the active pyridoxal 5'-phosphate enzyme and l-alanine. the activity of kynureninase is regulated in this manner by tran ...19751244119
hydroxykynureninase and the excretion of 3-hydroxyanthranilate by yeast.a comparative analysis of the kynureninase-type activity found in various organisms has demonstrated two forms of enzyme. one, inducible by tryptophan, has a relatively low km for l-kynurenine, and is found in microorganisms such as pseudomonas fluorescens and neurospora crassa. the other, unaffected by tryptophan, has a low km for l-3-hydroxykynurenine and is found in a wide variety of organisms, including molds, amphibia, birds and mammals. the yeast saccharomyces cerevisiae lacks the inducibl ...19751244118
genetic control of radiation sensitivity and dna repair in neurospora.radiation sensitivity in the fungus neurospora crassa is under the control of at least eight distinct loci and is also affected by cytoplasmic factors. although radiation-sensitive mutants which affect inter- or intragenic meiotic recombination have not been isolated, mutants which are defective in the repair of pyrimidine dimers have been found. evidence from both mutational and biochemical studies shows that neurospora has an excision-repair system for pyrimidine dimers which is very similar t ...19751103873
kinetic studies on the specificity of chelate-iron uptake in aspergillus.three strains of the fungus aspergillus, aspergillus quadricinctus (e. yuill), a. fumigatus (fresenius), and a. melleus (yukawa), each producing different iron-chelating compounds during iron-deficient cultivation, were used for 55fe3+ uptake measurements. iron from chelates of the ferrichrome-type family was taken up by young mycelia of all strains tested, irrespective of the ferrichrome-type compound these strains predominantly produce in low-iron cultures. ferrichrysin-producing strains, howe ...19751099079
characterization of dna condensates induced by poly(ethylene oxide) and polylysine.high-molecular-weight dna is known to collapse into very compact particles in a salt solution containing polymers like poly(ethylene oxide) [(eo)n] or polyacrylate. the biological relevance of this phenomenon is suggested by our recent finding that high concentrations of the highly acidic internal peptides found in the mature t4 bacteriophage head, as well as poly(glutamic acid) and poly(aspartic acid), can collapse dna in a similar manner. the structure of dnas collapsed by various methods has ...19751060108
site of cleavage of superhelical phix174 replicative form dna by the single strand-specific neurospora crassa endonuclease.experiments with the neurospora crassa single strand-specific endonuclease have provided evidence for the existence of regions of partially single-stranded character in covalently closed superhelical replicative form dna of phix174. the nuclease converts the superhelical molecules to either singly hit relaxed circular or doubly hit linear molecules. we show that the initial cleavage of phix174 superhelical dna is a "nick" bounded by a 5'-phosphate and a 3'-hydroxyl; no nucleotides are excised as ...1976942717
[a flavinogenic mutant of the yeast pichia guilliermondii with impaired iron transport].a mutant of the yeast pichia guilliermondii was produced by means of uv; the mutant was capable of riboflavin overproduction in the presence of high concentrations of iron in the medium. the content of total and non-hemin iron and cytochrome c, and the activity of catalase, were lower in the cells of the mutant than in the parent cells, while the activity of riboflavin synthetase was higher. the content of iron in the cells increased when the mutant was cultivated on media with citric acid, side ...1976933879
differential excision from dna of the c-8 and n2 guanosine adducts of n-acetyl-2-aminofluorene by single strand-specific endonucleases.purified duck reticulocyte dna was reacted in vitro with [9-14c]-n-acetoxy-n-acetyl-2-aminofluorene. hydrolysis of the [14c]-n-acetyl-2-aminofluorene-modified dna followed by sephadex lh-20 column chromatography showed that 85% of the dna-bound [14c]-n-acetyl-2-aminofluorene was n-(deoxyguanosin-8-yl)-n-acetyl-2-aminofluorene and 15% was 3-(deoxyguanosin-n2-yl)-n-acetyl-2-aminofluorene. when this modified dna was incubated with the single strand-specific nuclease, s1, and the undigested fraction ...1977908018
determination of the absolute configuration at c-20 and c-24 of ergosterol in ascomycetes and basidiomycetes by proton magnetic resonance spectroscopy.samples of ergosterol isolated from saccharomyces cerevisiae, neurospora crassa, and agaricus sp., and commercial ergosterol all displayed identical proton magnetic resonance (pmr) spectra at 220 mhz. from the effects produced on the doublet for c-21 by epimerization at c-20 and c-24 in sterols of known configuration, the absolute configurations at these positions in ergosterol were determined. the data demonstrate that ergosterol from both ascomycetes and basidiomycetes is the same and that at ...1977853879
in situ effects of s1 endonuclease (neurospora crassa) on pachytene chromatin of xenopus laevis females at metamorphosis. 1977837986
the catecholase activity of neurospora tyrosinase.a highly purified preparation of tyrosinase from neurospora crassa was isolated with a view to elucidating its mechanism of action. both the resting and functioning molecular weights of the enzyme were determined as 33000 plus or minus 2000 and kinetic data in conjunction with binding studies indicated the presence of only one site within the enzyme for binding phenolic substrates. kinetic constants for several 0-diphenols and for the inhibitors cyanide and benzoic acid were determined and the k ...1975807476
formation of nadph-nitrate reductase activity in vitro from aspergillus nidulans niad and cnx mutants.mutants of a. nidulans at several loci lack detectable nadph-nitrate reductase activity. these loci include niad, the structural gene for the nitrate reductase polypeptide, and five other loci termed cnxabc, e, f, g and h which are presumed to be involved in the formation of a molybdenum-containing component (mcc) necessary for nitrate reductase activity. when forzen mycelia from a. nidulans deletion mutant niad26 were homogenized in a ten broeck homogenizer together with frozen mycelia from eit ...1976796678
isolation and characterization of isocitrate lyase from a thermophilic bacillus sp.isocitrate lyase was isolated in homogeneous state from a thermophilic bacillus. the enzyme has a mol.wt. of 180000 and a pi of 4.5 and contains threonine as the n-terminal residue. it resembles in size the cognate enzyme from the mesophilic bacterium pseudomonas indigofera, but is smaller than the enzyme from the eukaryotic fungus neurospora crassa. all three lyases are tetramers and similar in amino acid composition, but the thermophile enzyme is distinctive from its mesophilic coutnerparts in ...1978687365
fungal transformation of naphthalene.eighty-six species of fungi belonging to sixty-four genera were examined for their ability to metabolize naphthalene. analysis by thin-layer and high pressure liquid chromatography revealed that naphthalene metabolism occurred in forty-seven species belonging to thirty-four genera from the major fungal taxa. all organisms tested from the order mucorales oxidized naphthalene with species of cunninghamella, syncephalastrum and mucor showing the greatest activity. significant metabolism was also ob ...1978678019
repair of daughter strand gaps in nascent dna from mouse epidermal cells treated with dihydrodiol epoxide derivatives of benzo[a]pyrene.alkaline sucrose gradient analysis of [methyl-3h]thymidine-pulse-labeled dna was used to study the effect of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (benzo[a]pyrene-diol epoxide i), a potent mutagen and carcinogen, and (+/-)-7 beta,8 alpha-dihydroxy-9 beta,10 beta-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (benzo[a]pyrene-diol epoxide ii), a weaker mutagen and carcinogen, on the size of newly synthesized dna in primary cultures of mouse epidermal cell ...1979508766
structural defects in rat liver deoxyribonucleic acid. endogenous single-strained regions in comparison with damage induced in vivo by a carcinogen.rat liver dna may be separated into two fractions by stepwise elution from benzoylated-deae-cellulose with nacl and caffeine solutions respectively. other studies using bacterical and yeast dna suggested that the first fraction contains native dna, whereas the second may exhibit some degree of single-stranded character. in the present experiments, chromatography of dna was monitored by labelling in vivo with [methyl-3h]thymidine in rats previously subjected to partial hepatectomy. in animals kil ...1979486085
studies on the transcription complex of escherichia coli rna study the chain elongation phase of enzymatic rna synthesis ternary transcription complexes with t7 dna or poly[da) - (dt)] as template were isolated by gel exclusion chromatography. the dna in these complexes contains single-stranded regions which are recognized by a single-strand-specific nuclease from neurospora crassa. the non-codogenic dna strand in the poly[(da) - (dt)] ternary complex is preferentially hydrolysed by the nuclease. the polymerase protects predominantly the codogenic stra ...1977336358
introduction. membrane transport of peptides.carrier-mediated membrane transport of small peptides is now realized to be a process of wide biological distribution, occurring not only in the small intestine and elsewhere in the animal body but also in bacteria, yeast, the mould neurospora crassa, and probably in higher plants during the germination of seeds. the important features of peptide transport are outlined, and possible relationships between peptide transport and hydrolysis are discussed. peptide transport is a stereochemically spec ...1977244390
properties of the glycoprotein laccase immobilized by two methods.laccase (p-diphenol:oxygen oxidoreductase; ec from neurospora crassa has been immobilized by two different procedures: (1) covalent attachment to sepharose 4b activated with cyanogen bromide, and (2) adsorption to concanavalin a-sepharose via the carbohydrate moiety. except for small changes in the michaelis-menten constants, no differences were noted in the enzymological properties of the immobilized enzymes when compared to free enzyme. the carbohydrate moiety of laccase involved in ...1975242172
regulation of glycolysis in neurospora crassa. kinetic properties of pyruvate kinase.pyruvate kinase (atp:pyruvate phosphotransferase, ec, extracted from the mycelium of neurospora crassa has been purified 560-fold by precipitation with ammonium sulphate, chromatography with deae-sephadex, and gel filtration with sephadex g-200. potassium and magnesium are required for enzyme activity. fructose, 1,6-diphosphate is the only physiological activator found for the enzyme. in decreasing order of potency, citrate, oxalacetate, calcium, and atp are inhibitors. phosphoenolpyru ...1975241893
proteolytic enzymes of neurospora crassa. purification and some properties of five intracellular proteinases.five intracellular proteolytic enzymes from neurospora crassa were isolated and partially characterized: an acidic and an alkaline endopeptidase, one carboxypeptidase and two aminopeptidases. all these proteinases were purified from the same crude extract to homogenity by heat treatment, precipitation with ammonium sulfate, chromatography on deae-cellulose, cm-cellulose, deae-sephadex, hydroxyapatite and by gel filtration. the acid proteinase hydrolysed acid-denatured haemoglobin at ph 3.0. the ...1975240706
regulation of two extracellular proteases of neurospora crassa by induction and by carbon-nitrogen and sulfur-metabolite repression. 1975240316
neurospora crassa invertase. a study of amino acids at the active center.1. the effects on neurospora crassa invertase (beta-d-fructofuranoside fructohydrolase, ec of a variety of group specific reagnets and other potential inhibitors were determined during a search for an irreversible inhibitor of the enzyme. aniline, pyridoxal, enzyme substrate and products did not inactivate invertase under reducing conditions. bromoacetic acid, iodoacetic acid, iodoacetamide, p-chloromercuribenzoate, hydroxylamine and 2-hydroxy-5-nitrobenzyl bromide were also ineffectiv ...1975239750
an altered invertase in the cot-2 mutant of neurospora crassa.because the cot-2 and inv loci of neurospora crassa are closely linked, the invertase from the morphological mutant, cot-2, was examined. the cot-2 strains produce an invertase with altered heat sensitivity, km, and ratio of heavy to light forms. the cellular localization of cot-2 invertase is different from that of the wild type. there were no observable changes in the energy of activation or the ph optimum of cot-2 invertase, and some of the differences detected were not apparent under culture ...1986239095
effect of ph and biotin on a circadian rhyythm of conidiation in neurospora crassa.expression of a circadian rhythm of conidiation in neurospora crassa is enhanced in cultures grown on medium that is neutral or deficient in biotin.1975237880
beta-galactosidases from neurospora crassa. 1975237204
solubilization of valine-sensitive acetohydroxy acid synthetase from neurospora mitochondria.acetohydroxy acid synthetase [ec] of neurospora crassa has been solubilized from a mitochondrial pellet fraction by sonic treatment in 1.0 m potassium phosphate buffer at ph 7.5 containing 10 mm mgso4 and centrifugation at 180,000 x g for 20 min. the soluble enzyme thus obtained has a high specific activity and a high sensitivity to valine comparable to the original mitochondrial pellet suspension when the activity was determined in high concentrations of potassium phosphate.1975237000
intracellular localization and properties of glycerokinase and glycerophosphate dehydrogenase in neurospora crassa. 1975236729
glucose-6-phosphate dehydrogenase from neurospora crassa. 1975236436
endogenous purine metabolism in the conidia of wild type and certain adenine mutants of neurospora crassa. i. the nature of the reserve pools and pool utilization during adenine starvation.conidia of four adenine auxotrophs (ad 9, ad 3b, ad 8 and ad 4) of neurospora crassa differ in their ability to germinate on adenine-deficient medium. a large percentage of the ad 9 and ad 3b mutant conidia germinate while those of ad 8 and ad 4 mutant do not. no correlation was found between the size of the conidial purine reserves and the conidial ability to germinate. in all the strains the major fraction of the conidial purine reserve pools was inosine. the ad 8 and ad 4 mutants are blocked ...1975236005
the regulation of myo-inositol-1-phosphate-synthase activity from neurospora crassa by pyrophosphate and some cations.the effect of several cations on the inhibition by ppi of the enzyme myo-inositol-1-phosphate synthase (1l-myo-inositol-1-phosphate lyase (isomerizing) ec from neurospora crassa was studied. the study wastol biosynthesis can occur in the presence of an intracellular ppi concentration which exceeds the ki for the enzyme by 350-fold. the inhibition of enzyme activity by ppi,at ph 7.7, was reversed, in decreasing order of effectiveness, by mn-2, fe-31975236002
studies on the in vitro inactivation of the neurospora crassa assimilatory nitrite reductase in the presence of reduced pyridine nucleotides plus vitro inactivation of neurospora crassa nitrite reductase (nad(p)h: nitrite oxidoreductase, ec can be obtained by preincubation of the enzyme with reduced pyridine nucleotide plus fad. the presence of nitrite or hydroxylamine, electron acceptors for the n. crassa nitrite reductase, or cyanide, sulfite or arsenite, competitive inhibitors with respect to nitrite of this enzyme, protects the enzyme against this inactivation. anaerobic experiments reveal that oxygen is required in order ...1975235301
nicotinamide 3,n4-ethenocytosine dinucleotide, an analog of nicotinamide adenine dinucleotide. synthesis and enzyme studies.a structural analog of nad+, nicotinamide 3,n-4ethenocytosine dinucleotide (epsilonncd+), has been synthesized, characterized, and compared in activity with the natural coenzyme in several enzyme systems. the vmax and apparent km values were determined for nad+, epsilonncd+, and epsilonnad+ (nicotinamide 1, n6-ethenoadenine dinucleotide) with yeast alcohol, horse liver alcohol, pig heart malate, beef liver glutamate, and rabbit muscle lactate and glyceraldehyde-3-phosphate dehydrogenases. the vm ...1975234741
unidirectional gene conversion associated with two insertions in neurospora crassa mitochondrial dna.the mitochondrial phenotype of [poky] and other extranuclear neurospora mutants is known to predominate over that of wild type in heteroplasmons. in the present work, we have investigated the interaction between wild-type and [poky] mtdnas using as many as four physical markers to distinguish the two types of mtdnas. two insertions, one of 1200 bp in eco ri-5 and the other 50 bp in eco ri-9, are identified as sites of high frequency, unidirectional gene conversion leading to their spread through ...1979232451
regulation of neurospora crassa nucleosidases by some environmental factors.enzymic cleavage of n-glycosidic bonds of amp, gmp, and inosine by the cell-free extracts of neurospora crassa has been studied. the enzymic activities with these substrates appear to be discrete from one another. the levels of these enzymes in the cell vary with age, and are dependent upon the inoculum size, aeration rate, and phosphate level in the medium. glucose (or ribose) controls the phosphate-mediated repression of all the three nucleosidases of this fungus.1979231866
adenylyl cyclase deficient cr-1 (crisp) mutant of neurospora crassa: cyclic amp-dependent nutritional deficiencies.the inability to synthesize cyclic amp drastically affects the nutritional metabolism of neurospora crassa. the adenylyl cyclase-less mutant cr-1 (crisp) did not utilize several carbon sources, including glycerol, mannitol, arabinose, and casaminoacids. however, in glucose or acetate it grew as well as the wild type. the following evidence suggested that these nutritional deficiencies were a direct result of the cr-1 mutation: (i), in crosses to wild type they segregated together with the crisp ...1979230797
nuclear mutants of neurospora crassa temperature-sensitive for the synthesis of cytochrome aa3. mitochondrial protein synthesis and analysis of the polypeptide composition of cytochrome c oxidase.three previously isolated mutants of neurospora crassa, temperature-sensitive for the production of cytochrome aa3, have been further analyzed. these mutants have a slightly reduced capacity for mitochondrial protein synthesis when grown at 41 degrees c, although this relative deficiency appeared to be no greater than the deficiency in other cytochrome-aa3-deficient mutants. thermolability studies revealed that the cytochrome c oxidase purified from each of the mutants grown at 23 degrees c is n ...1979230040
is the mitochondrially made subunit 2 of cytochrome oxidase synthesized as a precursor in neurospora crassa? 1979228973
control of chromatin transcription by a cyclic adenosine 3',5'-mono-phosphate-stimulated phosphorylation in neurospora crassa. 1979227738
conversion of a mitochondrial precursor polypeptide into subunit 1 of cytochrome oxidase in the mi-3 mutant of neurospora crassa.1. the cytochrome-alpha alpha 3-deficient mi-3 cytoplasmic mutant of neurospora crassa synthesizes a mitochondrial translation product which crossreacts with antibodies specific to subunit 1 of cytochrome oxidase. the immunoprecipitated polypeptide migrates more slowly during gel electrophoresis than the authentic 41 000-mr subunit 1 of the wild-type enzyme. an apparent molecular weight of about 45 000 was estimated for the mutant product. 2. radioactive labelling experiments in vivo show that t ...1979227683
isolation of mitochondrial succinate: ubiquinone reductase, cytochrome c reductase and cytochrome c oxidase from neurospora crassa using nonionic detergent.the electron transfer complexes, succinate: ubiquinone reductase, ubiquinone: cytochrome c reductase, and cytochrome c: o2 oxidase were isolated from the mitochondrial membranes of neurospora crassa by the following steps. modification of the contents of the complexes in mitochondria by growing cells on chloramphenicol; solubilisation of the complexes by triton x-100; affinity chromatography on immobilized cytochrome c and ion exchange and gel chromatography. ubiquinone reductase was obtained in ...1979226365
effects of carbon sources on the levels of fructose 1,6-biphosphathase in neurospora crassa. 2000225772
purification and subunit structure of nicotinamide adenine dinucleotide specific isocitrate dehydrogenase from neurospora crassa.neurospora crassa nicotinamide adenine dinucleotide specific isocitrate dehydrogenase (ec has been purified to homogeneity by the criteria of disc gel electrophoresis and sedimentation equilibrium. purification of the enzyme is facilitated by the presence of phenylmethanesulfonyl fluoride and by the use of a ribose-linked adenosine 5'-monophosphate affinity column. the enzyme appears to be composed of nonidentical subunits of molecular weights 42 800 and 38 300 as estimated by polyacry ...1979224915
cytochrome c oxidase subunits in nuclear and extranuclear cytochrome-aa3-deficient mutants of neurospora crassa.the mitochondria of cytochrome-aa3-deficient neurospora crassa mutants were screened for the seven polypeptide constiuents of cytochrome c oxidase. the polypeptides of the holoenzyme and the unassembled or partially assembled subunits were detected by sodium dodecyl sulfate/acrylamide gel electrophoresis of immunoprecipitates obtained with antiserum to the holoenzyme as well as to several individual subunits. with respect to the mitochondrially synthesized polypeptides of the oxidase, subunits 1 ...1979223848
catalase of neurospora crassa. 2. electron paramagnetic resonance and chemical properties of the prosthetic group. 1969223625
biogenesis of mitochondrial membrane proteins in neurospora crassa. 1979223007
lipid and cell wall changes in an inositol-requiring mutant of neurospora inositol deficiency in the inositol-requiring (inl) mutant of neurospora crassa led to changes in the composition of the inositol-containing lipids and the cell wall. on deficient levels of inositol, phosphatidyl inositol decreased by 23-fold, di(inositolphosphoryl) ceramide decreased by 4-fold, and monoinositolphosphoryl ceramide increased slightly. the inositol deficiency also led to an aberrant hyphal morphology and changes in both the amount of cell wall and the amino sugar content of the ...1982220215
control of cyclic adenosine 3',5'-monophosphate levels by depolarizing agents in has been reported that diverse treatments which depolarize the plasma membrane of neurospora crassa produce rapid increases in cyclic adenosine 3',5'-monophosphate (cyclic amp) levels. in the current study, membrane active antibiotics, which are known or putative depolarizing agents, were found to produce similar cyclic amp increases, not only in n. crassa, but also in the distantly related fungi saccharomyces cerevisiae and mucor racemosus. uncouplers of oxidative phosphorylation, which have ...1979220213
properties of two cyclic nucleotide-deficient mutants of neurospora crassa.studies on the crisp-1 (cr-1), cyclic adenosine 3',5'-monophosphate (camp)-deficient mutants of neurospora crassa were undertaken to characterize the response of these mutants to exogenous cyclic nucleotides and cyclic nucleotide analogs. a growth tube bioassay and a radioimmune assay for cyclic nucleotides yielded the following results. (i) 8-bromo camp and n6-monobutyryl camp but not dibutyryl camp are efficient camp analogs in neurospora, stimulating mycelial elongation of the cr-1 mutants. e ...1979220210
nuclear mutants of neurospora crassa temperature-sensitive for the synthesis of cytochrome aa3. i. isolation and preliminary characterization.three nuclear mutants of neurospora crassa, temperature-sensitive for the synthesis of cytochrome aa3 have been isolated. when grown at 41 degrees c the mutants have large amounts of kcn-insensitive respiration, reduced amounts of cytochrome aa3 and cytochrome c oxidase activity, and grow more slowly than wild-type cultures grown at the same temperature. when the mutants are grown at 23 degrees c, they are virtually indistinguishable from wild-type strains. the mutants were selected on the basis ...1979216900
a regulatory system controlling the production of cytochrome aa3 in neurospora crassa.the mitochondria of the cyt-2-1, cya-3-16, cya-4-23 and 299-1 nuclear mutants and the [mi-3] and [exn-5] cytoplasmic mutants of neurospora crassa are deficient in cytochrome aa3, while the cyb-1-1 and cyb-2-1 mutants have mitochondrial b-cytochrome deficiencies. however, the mitochondria from cyb-1-1 cyt-2-1, cyb-1-1 [mi-3] and cyb-2-1 [mi-3] double mutants contain 30% to 50% of the amount of cytochrome aa3 that is present in mitochondria from wild-type; i.e. cyb-1-1 and cyb-2-2 act as suppresso ...1979216899
biogenesis of cytochrome c in neurospora crassa. synthesis of apocytochrome c, transfer to mitochondria and conversion to holocytochrome c.1. precipitating antibodies specific for apocytochrome c and holocytochrome c, respectively, were employed to study synthesis and intracellular transport of cytochrome c in neurospora in vitro. 2. apocytochrome c as well as holocytochrome c were found to be synthesized in a cell-free homogenate. a precursor product relationship between the two components is suggested by kinetic experiments. 3. apocytochrome c synthesized in vitro was found in the post-ribosomal fraction and not in the mitochondr ...1984215405
an epr analysis of cyanide-resistant mitochondria isolated from the mutant poky strain of neurospora analysis of the paramagnetic components present in mitochondria isolated from the poky mutant of neurospora crassa is described. the study was undertaken with a view to shedding light on the nature of the cyanide- and antimycin a-resistant alternative terminal oxidase which is present in these preparations. of the ferredoxin-type iron-sulfure centers, only centers s-1 and s-2 of succinate dehydrogenase could be detected in significant quantities. paramagnetic centers attributable to site i we ...1978214109
complex iii from mitochondria on neurospora crassa: purification, characterization, and resolution. 1987213696
purification of cytochrome oxidase from neurospora crassa and other sources. 1978213692
isolation of precursors of cytochrome oxidase from neurospora crassa: application of subunit-specific antibodies and protein a from staphylococcus aureus.a novel immunological procedure has been applied for the isolation of precursors of cytochrome oxidase. it involves antibodies to individual subunits of the oxidase and protein a from staphylococcus aureus linked to a sepharose support. unassembled (free) 'subunits' as well as a labile complex containing five polypeptide components of the oxidase were isolated from mitochondrial extracts by this technique. the procedure is superior to the previously used double-immuno-precipitation method, becau ...1978213273
cyclic amp and cyclic gmp in germinating conidia of neurospora crassa.a new method for obtaining synchronous germination allowed accurate time-course studies of endogenous levels of cyclic adenosine 3',5'-monophosphate and cyclic guanosine 3',5'-phosphate in germinating conidia of neurospora crassa. the levels of both cyclic nucleotides remained constant throughout germination, showing that they neither signal nor respond to any of the biochemical changes which are known to occur in the germination process. conidal germination was approximately normal in three cr- ...1978211974
effect of carbon source on enzymes involved in glycerol metabolism in neurospora crassa.specific activities of eight enzymes involved in glycerol metabolism were determined in crude extracts of three strains of neurospora crassa after growth on six different carbon sources. one of the strains was wild type, which grew poorly on glycerol as sole carbon source; the other two were mutant strains which were efficient glycerol utilizers. a possible basis for this greater efficiency of glycerol utilization was catabolite repression of glyceraldehyde kinase by glycerol in wild type, and t ...1987211971
a nuclear mutant of neurospora crassa lacking subunit 1 of cytochrome c oxidase. 1989210181
a possible model for the structure of the neurospora carbamoyl phosphate synthase-aspartate carbamoyl transferase complex enzyme.the pyrimidine-3 locus of neurospora crassa specifies a multienzyme complex comprising pyrimidine-specific carbamoyl phosphate synthase (cpspyr) and aspartate carbamoyl transferase (act). it appears to be divided into a translationally proximal cps-specific region and a distal act-specific region. levels of complementation for act activity between pairs of four pyr-3 cps+ act- mutants showed a range from 12% to 68% of the wild-type level of the enzyme. this is interpreted as interallelic complem ...1978209307
disappearance of the cyanide-insensitive pathway of oxidation in mitochondria of mi-1 mutant of neurospora crassa in vitro.oxidation of exogenous nadh in mitochondria isolated from wild type and mi-1 mutant of neurospora crassa decreases rapidly in vitro. in mi-1 mutant mitochondria the inactivation concerns the alternate pathway of oxidation whereas in the wild type it involves an unknown component of the respiratory chain. the activity of the primary nadh dehydrogenase is constant within the time of the experiments (2-4 h). nadh oxidase is not inactivated if oxygen is removed from the incubation medium by nitrogen ...1978208334
structural analysis of viral replicative intermediates isolated from adenovirus type 2-infected hela cell nuclei.deoxyribonucleoprotein complexes released 17 h postinfection from adenovirus type 1 (ad2)-infected hela cell nuclei were shown by electron microscopy to contain filaments much thicker (about 200 a [20 nm]) than double-stranded dna (about 20 a [2 nm]). the complexes were partially purified through a linear sucrose gradient, concentrated, and further purified in a metrizamide gradient. the major protein present in the complexes was identified as the 72,000-dalton (72k), adenovirus-coded single-str ...1978207893
the state of copper in neurospora laccase.1. neurospora crassa laccase has been prepared from the growth medium and studied by optical absorption, circular dichroism and electron paramagnetic resonance (epr) spectroscopy. the molecular weight, the copper content and the amino acid composition have also been determined. 2. the molecular weight as determined by gel filtration in 6 m guanidine hydrochloride and by sodium dodecyl sulfate gel electrophoresis is found to be 64 000. the enzyme contains 3.8 copper ions per 64 000. 3. the visibl ...1992207349
electron transport in the cni-1 mutant of neurospora crassa.1. mitochondria from the nuclear mutant cni-1 have no optically detectable cytochrome aa3 in early log phase growth. these mitochondria have a high level of respiration that is not inhibited by cyanide but is inhibited by salicylhydroxamic acid. they also show a substantial amount of cyanide-sensitive respiration. 2. as cultures of mutant cni-1 age, flux through the hydroxamate-sensitive pathway decreases markedly while flux through the cytochrome chain remains constant. 3. growth studies with m ...1992206437
ageing of neurospora crassa. vi. cytochemical and cytological correlates of senescence in three model systems. 1993204837
ageing of neurospora crassa. v. lipid peroxidation and decay of respiratory enzymes in an inositol auxotroph. 1993204836
cytochrome c-specific protein-lysine methyltransferase from neurospora crassa. purification, characterization, and substrate requirements. 1978203592
kinetic studies on the transport of cytoplasmically synthesized proteins into the mitochondria in intact cells of neurospora crassa.the transport of cytoplasmically synthesized mitochondrial proteins was investigated in whole cells of neurospora crassa, using dual labelling and immunological techniques. in pulse and pulse-chase labelling experiments the mitochondrial proteins accumulate label. the appearance of label in mitochondrial protein shows a lag relative to total cellular protein, ribosomal, microsomal and cytosolic proteins. the delayed appearance of label was also found in immunoprecipitated mitochondrial matrix pr ...1977202461
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