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effect of pre-treatment with 5-bromouracil in an ultraviolet sensitive strain of neurospora crassa. 1977146631
isolation and preparation of pretyrosine, accumulated as a dead-end metabolite by neurospora crassa.pretyrosine is an amino acid intermediate of phenylalanine and/or tyrosine biosyntheses in a variety of organisms. a procedure for the isolation of high-quality pretyrosine as the barium salt is described. stable solutions of ammonium pretyrosine that are suitable for use as substrate in enzyme assays can be prepared in good yield with relatively few purification steps. a triple mutant of neurospora crassa, bearing genetic blocks corresponding to each initial enzyme step of the three pathway bra ...1977144721
germination-defective mutant of neurospora crassa that responds to siderophores.a conditionally germination-defective mutant of neurospora crassa has been found to be partially curable by ferricrocin and other siderophores. the mutant conidia rapidly lose their membrane-bound siderophores when suspended in buffer or growth media. germination is consequently delayed unless large numbers of conidia are present (positive population effect). this indicates that the mutant has a membrane defect involving the siderophore attachment site.1977144720
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora crassa. ix. isolation and sequences of several large cyanogen bromide peptides.the isolation and sequences of several large peptides from cyanogen bromide cleavage of the 1030-residue polypeptide chain of the nad-specific glutamate dehydrogenase of neurospora crassa are described. one of these is in the 669-residue sequence of the cooh-terminal end of the protein. the remaining peptides have been aligned in two partial sequences in the nh2-terminal portion of the polypeptide chain.1977199604
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora. viii. isolation and sequences of peptides from a tryptic hydrolysate of the maleylated protein.the nad-specific glutamate dehydrogenase of neurospora crassa was s-carboxymethylated with [14c]iodoacetate, maleylated, and hydrolyzed with trypsin. the isolation and sequences of the resulting peptides are described. these peptides gave information on the structure of the protein that was previously unknown and gave many overlaps of previously isolated segments of the protein.1977199603
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora. vii. isolation and sequences of three large cyanogen bromide peptides.the isolation and sequences of three peptides of large size from a cyanogen bromide digest of the nad-specific glutamate dehydrogenase of neurospora crassa are reported. these three peptides comprise 86, 117, and 134 residues, respectively, and represent approximately 30% of the estimated 1030 residues in the peptide chain.1977199602
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora. vi. isolation and sequences of eighteen fragments from the cyanogen bromide digest.the 1030-residue polypeptide chain of the nad-specific glutamate dehydrogenase of neurospora crassa was fragmented by treatment with cyanogen bromide. the isolation and sequences of 18 fragments ranging in size from 4 to 51 residues are described. some of these peptides proved to be cleavage products resulting from hydrolysis at acid-sensitive aspartyl-prolyl bonds. some overlaps could be deduced on the basis of known sequences of peptides obtained by tryptic hydrolysis.1977199601
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora. v. tryptic peptides.the isolation and sequences of an additional 80 peptides from a tryptic digest of the nad-specific glutamate dehydrogenase of neurospora crassa are reported. these include an additional peptide containing a lysine residue labeled at the epsilon-amino group with pyridoxal 5'-phosphate. the sequence of this peptide shows some homology with the reactive lysine residue of other glutamate dehydrogenases.1977144134
morphology of slime variants of neurospora crassa growing on a glass surface in liquid medium. 1. under normal conditions and 2. in the presence of inhibitors. 1977145837
an inducible acetate transport system in neurospora crassa conidia.neurospora crassa conidia possess an active transport system for the uptake of acetate. this system was characterized as: (a) energy dependent; (b) taking place against a concentration gradient; (c) saturating at higher substrate concentrations and (d) competitively inhibited by propionate. activity of the acetate transport system can be further enhanced by preincubating conidia in 1 mm acetate medium for 180 min (the inducible transport system). the conidial system and the inducible system have ...1977144526
unstable s-adenosylmethionine synthetase in an ethionine-resistant strain of neurospora crassa.a pleitropic ethionine-resistant mutant of neurospora contains an s-adenosylmethionine synthetase that is labile to heat and dialysis but exhibits normal kinetics for methionine and ethionine.1977144115
adaptive changes in phosphate uptake by the fungus neurospora crassa in response to phosphate supply.the phosphate uptake rate of neurospora crassa germlings growing exponentially in media containing phosphate at concentrations between 10 mm and 50 micronm was virtually constant. the uptake characteristics of these germlings were studied in detail assuming the simultaneous operation of two uptake systems, one of low affinity and one of high affinity. the km of the low-affinity system was constant after growth at phosphate concentrations greater than 1 mm but became progressively lower as the co ...1977144114
kinetic characterization of the two phosphate uptake systems in the fungus neurospora crassa.the kinetics of phosphate uptake by exponentially growing neurospora crassa were studied to determine the nature of the differences in uptake activity associated with growth at different external phosphate concentrations. conidia, grown in liquid medium containing either 10 mm or 50 micronm phosphate, were harvested, and their phosphate uptake ability was measured. initial experiments, where uptake was examined over a narrow concentration range near that of the growth medium, indicated the prese ...1977144113
cyclic amp and the plasma membrane potential in neurospora crassa.diverse treatments, which have been shown by slayman, c. l. (1977) in water relations in membrane transport in plants and animals (jungreis, a., hodges, t. k., kleinzeller, a., and schultz, s. g., eds) pp. 69-86, academic press, new york, to depolarize the plasma membrane of neurospora, increase levels of adenosine 3':5'-monophosphate (cyclic amp) in the organism. the treatments include those producing large transport fluxes of metabolizable or nonmetabolizable compounds, rapid temperature drops ...1977198403
mitochondrial ribosome assembly in neurospora crassa. chloramphenicol inhibits the maturation of small ribosomal subunits. 1977146091
regulation of glutamine synthetase in fed-batch cultures of neurospora crassa. 197721661
the 73 s ribosome of neurospora crassa is the native mitochondrial ribosome. 1977143964
deficiency of subunit two of cytochrome oxidase in the mi-3 cytoplasmic mutant of neurospora crassa. 197772665
proof of de novo synthesis of the qa enzymes of neurospora crassa during induction.in neurospora crassa three inducible enzymes are necessary to catabolize quinic acid to protocatechuic acid. the three genes encoding these enzymes are tightly linked on chromosome vii near methionine-7 (me-7). this qa cluster includes a fourth gene, qa-1, which encodes a regulatory protein apparently exerting positive control over transcription of the other three qa genes. however, an alternative hypothesis is that the qa-1 protein simply activates preformed polypeptides derived from the three ...1977144915
uptake and efflux of adenine and its derivatives in neurospora crassa.conidia of wild-type neurospora crassa, preincubated for 3 1/2 h in growth medium, showed a typical triphasic pattern of adenine uptake. the three phases consisted of a quick initial uptake, followed by a plateau phase, and then by a resume lowered uptake. a study of the relative influx and efflux of [14c] adenine showed that the plateau phase in fact is a period of transmembrane movement of adenine and adenine metabolites. the efflux during the plateau phase essentially cancelled out all the in ...1977144552
preparation of polypeptide subunits of cytochrome oxidase from neurospora crassa.cytochrome oxidase was purified from neurospora crassa by ammonium sulfate fractionation in the presence of bile salts. the enzyme preparations contained 10-13 nmol of heme a per mg of protein; no other hemoproteins could be detected. dodecylsulfate gel electrophoresis resolved the enzyme complex into seven major bands, representing seven polypeptide subunits. a procedure is described that allows the isolation of these enzyme subunits on a large scale starting from a single batch of oxidase prep ...1977199436
role of lipids in the neurospora crassa membrane. ii. membrane potential and resistance studies; the effect of altered fatty acid composition on the electrical properties of the cell membrane.the effect of doubling the saturated fatty acid content on the electrophysiology of neurospora crassa membranes was studied. intracellular membrane input resistance (rm) and potential (em) were measured for wild-type (w/t) and cel- (tween 40) organisms as a function of temperature. over the 0 to 40 degrees c temperature range studied, mean em values of both w/t and cel- (tw 40) organisms increased from -160 to -210 mv. this difference is greater than that expected from nernst potential considera ...1977143534
the effect of phosphatidylcholine depletion on biochemical and physical properties of a neurospora crassa membrane mutant.by using the choline starvation process it is possible to deplete the membranes of neurospora crassa choline auxotroph chol-1 of phosphatidylcholine, without affecting the viability of germinated spores or whole mycelium. spin label probes were used to examine the possible dependence of the physical state of cellular lipids on the presence of phosphatidylcholine in the membranes. increased freedom of rotational motion of lipid soluble probes was regularly detected in choline-starved mycelium. th ...1977197995
nitrogen regulation of arginase in neurospora crassa.the final products of the arginine catabolism that can be utilized as a nitrogen source in neurospora crassa are ammonium, glutamic acid, and glutamine. the effect of these compounds on arginase induction by arginine was studied. in wild-type strain 74-a, induction by arginine was almost completely repressed by glutamic acid plus ammonium, whereas ammonium or glutamic acid alone had only moderate effects. arginine products of catabolism also repressed arginase induction. a mutant, ure-1, which l ...1977142762
purification of s-adenosylmethionine: epsilon-n-l-lysine methyltransferase. the first enzyme in carnitine biosynthesis.the initial steps of carnitine biosynthesis in neurospora crassa involve the methylation of the epsilon-amino group of lysine as follows: lysine a leads to monomethyllysine b leads to dimethyllysine c leads to trimethyllysine. the methyl donor is s-adenosylmethionine. an enzyme, s-adenosylmethionine:epsilon-n-l-lysine methyltransferase, has been purified from n. crassa to near homogeneity as judged by column chromatography, polyacrylamide gel electrophoresis, and ultracentrifugation. this protei ...1977142089
developmental-stage-dependent adenine transport in neurospora crassa.although germinated conidia of neurospora crassa transport adenine through two different systems, only one of these, namely, the general purine transport system, which transports adenine, hypoxanthine, guanine, and 6-methylpurine, is present in freshly harvested conidia of the wild type. the second system develops during germination. the latter system can transport adenine and 6-methylpurine. time course and kinetic studies of adenine transport in freshly harvested conidia of an ad-8 mutant indi ...1977142082
galactosyltransferase of neurospora.an enzyme, galactosyltransferase, able to catalyze the formation of galactose polymers was detected in cell-free extracts of a wild type strain of neurospora crassa. enzyme activity was found in both the supernatant and the particle fractions after centrifugation at 100,000 x g. the enzyme assayed in the 100,000 x g supernatant showed a 4fold difference in specific activity as compared to that found in the particle fraction.1977142643
site of action of iron in the induction of delta-aminolevulinate dehydratase in neurospora crassa. 1977142484
demonstration of specific aminopeptidase inhibitors in neurospora crassa. 1977142659
messenger ribonucleoprotein complexes isolated by oligodeoxythymidylate-cellulose chromatography from neurospora crassa polysomes.messenger ribonucleoprotein (mrnp) complexes were isolated from ethylenediaminetetraacetic acid-dissociated polysomes of neurospora crassa. approximately 15% of the [3h]uridine incorporated into polysomal ribonucleic acid (rna) during a 15-min pulse was eluted from oligodeoxythymidylate-cellulose as an mrnp complex. the isolated mrnp complexes exhibited sedimentation coefficients ranging from 15s to greater than 60s. rna isolated from these mrnp complexes sedimented in sucrose gradients between ...1977141447
composition and synthesis of cellular lipids in neurospora crassa during cellular differentiation.the synthesis of cellular lipids of neurospora crassa was measured during growth on low (2% sucrose)- and high (15% glucose)-carbohydrate supplementation. the amount of lipid per dry weight of cells does not change during the germination and early logarithmic growth periods, but the percentage of phospholipid in the lipid does increase, reaching a maximal value of 90% at 4 to 5 h after inoculation, at which time the phospholipid content of the cells is approximately 60 mumol/g (dry weight). the ...1977141445
nuclear cytochrome-deficient mutants of neurospora crassa: isolation, characterization, and genetic mapping. 1977142902
[histones of the fungi, endomyces magnusii and neurospora crassa].histones of endomyces magnusii and neurospora crassa were found to consist of four main fractions similar to calf thymus histones in their electrophoretic mobilities, molecular sizes and chromatographic behaviour on akrilex p-60. two of them are homologous to the most conservative histones h3 and h4. other two fractions correspond to the histones h2a and h2b; however, they have some pecularities. a fraction of n. crassa histones corresponding to the h2b was isolated in a homogeneous state by mea ...1977142527
characterization and in vitro translation of polyadenylated messenger ribonucleic acid from neurospora crassa.ribonucleic acid (rna) extracted from neurospora crassa has been fractionated by oligodeoxythymidylic acid [oligo(dt)]-cellulose chromatography into polyadenylated messenger rna [poly(a) mrna] and unbound rna. the poly(a) mrna, which comprises approximately 1.7% of the total cellular rna, was further characterized by sepharose 4b chromatography and polyacrylamide gel electrophoresis. both techniques showed that the poly(a) mrna was heterodisperse in size, with an average molecular weight similar ...1977140861
unsaturated fatty acid mutants of neurospora crassa.unsaturated fatty acid (ufa) auxotrophs of neurospora crassa were obtained by treatment of conidia with n-methyl-n'-nitro-n-nitrosoguanidine followed by isolation on media containing polyunsaturated fatty acids suspended in tergitol np-40. the 24 mutants for which reisolates were obtained from crosses with wild type were assigned to two complementation classes, ufa-1 and ufa-2, located on linkage group v. unsaturated fatty acids with varying degrees of unsaturation, chain length, and double-bond ...1977140860
biosynthesis of glycogen in neurospora crassa. existence of a glucoproteic intermediate in the initiation process.a soluble enzyme preparation (20,000 x g supernatant fraction), prepared from the mycelia of wild-type neurospora crassa, was capable of transferring [14c]glucose from udp-[14c]glucose into both trichloroacetic acid (tca)-soluble and tca-insoluble macromolecule products in the absence of added primer. these reactions did not require either high concentrations of salts or any other chemical reagents. two labeled products were formed; one was a glycogen-like polysaccharide and the other was a glyc ...197719440
amino acid replacements resulting from suppression and missense reversion of a chain-terminator mutation in neurospora.the neurospora crassa super-suppressor mutation, ssu-1, suppresses the auxotrophic phenotype of the mutant am(17) by inserting tyrosine at residue 313 of nadp-specific glutamate dehydrogenase, a position occupied in the wild type by glutamate. two classes of am(17) revertants due to further mutation within the am gene have, respectively, tyrosine and leucine at residue 313. these replacements are consistent with a chain-terminating codon in am(17) of either the amber (uag) or the ochre type (uaa ...197718380
characterization of plasma membrane adenosine triphosphatase of neurospora crassa.it has been proposed (slayman, c.l., long w.s., and lu, c.y.-h. (1973) j. membr. biol. 14, 305--338) that in neurospora crassa, a plasma membrane atpase functions to pump h+ ions out of the cell, thereby generating an electrochemical gradient that can drive transport processes. using the concanavalin a method of scarborough (scarborough g.a. (1975)j. biol. chem. 250, 1106--1111), we have prepared plasma membranes of neurospora and have deomonstrated that they do contain a distinct atpase activit ...197716897
effect of temperature and temperature shifts on growth and branching of a wild type and a temperature sensitive colonial mutant (cot 1) of neurospora crassa.growth of a temperature sensitive colonial mutant (cot 1) of neurospora crassa was compared with a wild type strain. the hyphal growth unit (the ratio between mycelial length and number of branches) of the wild type was not appreciably altered by temperature and there was a direct relationship between the specific growth rate (alpha) of these mycelia and their mean hyphal extension rate (e). the specific growth rate of cot 1 increased by about the same relative amount as the wild type between 15 ...1977142456
blue light-induced absorbance changes in membrane fractions from corn and neurospora.blue light-induced absorbance changes were measured from differentially centrifuged membrane fractions from dark-grown coleoptiles of zea mays l., and mycelia from an albino mutant of neurospora crassa. actinic irradiation caused changes in absorbance consistent with a flavinmediated reduction of a b-type cytochrome. both corn and neurospora showed similar light-minus-dark difference spectra, dose response curves, and kinetics of dark recovery after irradiation. the photoreducible cytochrome sys ...197716659974
characterization of neurospora crassa mutant stratins deficient in adenylate cyclase activity. 1977141907
properties of neurospora crassa plasma membrane atpase. 197718094
thymine 7-hydroxylase from neurospora crassa. substrate specificity studies.a partially purified preparation of thymine 7-hydroxylase (thymine, 2-oxoglutarate : oxygen oxidoreductase (7-hydroxylating), ec 1.14.11.6) from neurospora crassa was incubated with a number of pyrimidines chemically related to tyymine. 1. pyrimidines with oxygen or sulfur substituents on atoms nos. 2 and 4 as well as an alkyl group on atom nos. 1 or 5 were substrates. 2. km values were determined for 1-methyluracil, 1-ethyluracil, thymine, 6-azathymine, 1-methylthymine, 1-ethylthymine, 5-formyl ...1977139930
role of lipids in the neurospora crassa membrane. i. influence of fatty acid composition on membrane lipid phase transitions.the relationship between lipid composition and phase transition was investigated by differential scanning calorimetry for intact and membrane phospholipid extracts of wild-type (w/t) and the cel-(tw 40) mutant of neurospora crassa. the cel-(tw 40) mutant (grown on minimal, sucrose medium supplemented with tween 40 at approximately 34 degrees c) had approximately twice the saturated fatty acid content of w/t organisms grown at approximately 22 degrees c. the gel-liquid crystal phase transitions o ...1977140245
lecithin requirement for the sporulation process in neurospora crassa.reversible inhibition of conidiogenesis occurred when lecithin was depleted from neurospora membranes by choline starvation.1977140164
inhibition of germ tube formation in neurospora.phenethyl alcohol, m-cresol, and related compounds cause inhibition of germ tube formation in conidia of neurospora crassa. conidia continue to swell and form large spherical cells that are capable of multiple germ tube formation upon removal of inhibitor.197767112
a temperature-sensitive mutant of neurospora crassa deficient in cytochrome b.a nuclear gene mutant of neurospora crassa designated cyb-3 is deficient in cytochrome b and coenzyme qh2-cytochrome c reductase. nearly normal when grown at 25 degrees c, the strain expresses a mutant phenotype at 38 degrees c. mitochondria from cyb-3 mycelium, which has undergone 3-4 mass doublings at the elevated temperature, possess 3-fold less cytochrome b, 2-fold more cytochrome, c, 5-fold less coenzyme qh2-cytochrome c reductase activity, and require 3-fold less antimycin a per milligram ...1977141003
inhibition of aminoacyl-transfer ribonucleic acid synthetases and the regulation of amino acid biosynthetic enzymes in neurospora crassa.growth conditions that result in the accumulation of the tryptophan intermediate indoleglycerol phosphate or of the histidine intermediate imidazoleglycerol phosphate cause mycelia of neurospora crassa to exhibit an immediate and sustained increase in the differential rate at which the biosynthetic enzymes of the tryptophan, histidine, and arginine pathways are synthesized. these accumulated intermediates are shown to be inhibitors of the activity of aminoacyltransfer ribonucleic acid (trna) syn ...1977191433
the subunit structure of the arom multienzyme complex of neurospora crassa. a possible pentafunctional polypeptide chain.a new procedure for the purification of the arom multienzyme complex from neurospora crassa is presented. important factors are the inactivation of proteinases by phenylmethanesulphonyl fluoride and the use of cellulose phosphate as an affinity adsorbent. a homogeneous enzyme, with a specific shikimate dehydrogenase activity of 70 units/mg of protein, is obtained in 25% yield. polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate, combined with cross-linking studies using ...1977139889
genetic and kinetic analysis of neurospora crassa mtr mutants.allelic complementation occurs at the mtr (methyltryptophan resistance) locus. kinetic properties of neutral amino acid transport are altered for mtr mutants.1977139402
control of the production of orthophosphate repressible extracellular enzymes in neurospora crassa.the abilities of purine- and pyrimidine-requiring mutants to produce six orthophosphate repressible extracellular enzymes, alkaline phosphatase, 5'-nucleotidase, acid phosphatase, two nucleases and ribonuclease n1 were examined by culturing these mutants in low and high phosphate media containing nucleotide or nucleoside. all the purine requiring mutants produced significantly reduced amounts of alkaline phosphatase, 5'-nucleotidase, acid phosphatase, alkaline nuclease and acid nuclease ranging ...1977194139
characterization of the new osmotic mutants (os) which originated during genetic transformation in neurospora crassa. 1977141392
dna syntheses in course of meiotic development in neurospora crassa. 1977141391
the effect of various "magdala reds" in inducing paramorphic colony growth in neurospora crassa. 1977139210
energy-linked potassium uptake by mitochondria from wild-type and poky strains of neurospora crassa.mitochondria from neurospora crassa, like mammalian mitochondria, carry out rapid, energy-linked k+ uptake and h+ release in the presence of valinomycin. the maximal rate of k+ uptake was about 1.0 mumol/mg of mitochondrial protein per min and was seen at valinomycin concentrations in the range of 100 to 200 mug per mg of mitochondrial protein and at k+ concentrations of 4 mm or above. uptake could be supported either by substrate oxidation or by adenosine 5'-triphosphate (atp), and was inhibite ...1977138675
composition and photoinduced biosynthesis of the carotenoids of a protoplast-like neurospora crassa "slime" mutant.a spheroplast-like "slime" mutant of neurospora crassa (lacking a rigid cell wall) was found to synthesize an identical spectrum of carotenoids as wild type strains except for beta-carotene. furthermore strict photoregulation of the biosynthesis of these pigments as well as the characteristics of photoinduced carotenogenesis were also nearly identical in the mutant and in the wild type.1977138402
control of the production and partial characterization of repressible extracellular 5'-nucleotidase and alkaline phosphatase in neurospora crass.a new species of orthophosphate repressible extracellular 5'-nucleotidase (5'-ribonucleotide phosphohydrolase, ec 3.1.3.5) was found to be released into mycelial culture media when a wild type strain of neurospora crassa was grown on limiting amounts of phosphate. the production of 5'-nucleotidase and extracellular acid and alkaline phosphatase was inhibited by the addition of rifampicin when it was added at the later stage of mycelial growth, but not when it was added at a very early stage. the ...1977137748
reactions of the neurospora crassa nitrate reductase with nad(p) analogs.the assimilatory nadph-nitrate reductase (nadph:nitrate oxidoreductase, ec 1.6.6.3) from neurospora crassa is competitively inhibited by 3-aminopyridine adenine dinucleotide (aad) and 3-aminopyridine adenine dinucleotide phosphate (aadp) which are structural analogs of nad and nadp, respectively. the amino group of the pyridine ring of aad(p) can react with nitrous acid to yield the diazonium derivative which may covalently bind at the nad(p) site. as a result of covalent attachment, diazotized ...197712830
light-dependent carotenoid synthesis : x. lag-phase after a second illumination period in fusarium aquaeductuum and neurospora crassa.in dark grown mycelia of the fungi fusarium aquaeductuum lagh. and neurospora crassa the kinetics of carotenoid accumulation after brief illuminations were investigated. following a second illumination period photoinduced carotenoid biosynthesis started also only after a lag-phase. such a "secondary" lag-phase not only appeared when the pigment accumulation induced by the first light treatment had been completed, but also when the second illumination was given during the period of rapid caroteno ...197724420226
conditions of transformation by dna of neurospora crassa.the dna uptake and transformation of inositol-requiring recipient neurospora strains were investigated. exponentially growing cultures can accumulate 5-10 fold quantities of donor dna than older ones. the rate of dna uptake depends on the physiological state of the recipient cell, and on the molecular weight of donor dna. the exocellular dnase activity of the recipient culture may influence the dna uptake and the transformation process. "young" inositol-requiring neurospora crassa cultures can b ...1977150186
isolation of putrescine-requiring mutants of neurospora crassa.two auxotrophs of neurospora crassa have been isolated that give a positive growth response to putrescine, spermidine or spermine. one of the mutants is deficient in ornithine decarboxylase activity and has been designated put-i. both mutants map on linkage group vr, fail to complement and are infertile when crossed to one another, indicating that they are probably alleles. a putrescine auxotroph is incapable of suppressing a pro-4 mutant. the isolation of the mutants confirms that putrescine is ...1977145823
heterogeneous base distribution in mitochondrial dna of neurospora crassa.the mitochondrial dna of neurospora crassa has a heterogeneous intramolecular base distribution. a contiguous piece, representing at least 30% of the total genome, has a g+c content that is 6% lower than the overall g+c content of the dna. the genes for both ribosomal rnas are contained in the remaining, relatively g+c rich, part of the genome.1977141040
lack of mutagenicity of vinyl chloride in two strains of neurospora crassa.no detectable induction of mutations could be found in two strains of neurospora crassa after their conidia were treated with vinyl chloride, in ethanol solution and in its gaseous form. the results suggest that although n. crassa seems to lativating systems does not increase mutagenic activity of vinyl chloride in the two strains tested. at the same time these strains were mutated easily by uv and methyl methanesulfonate.1977138087
new class of ribonucleic acid in neurospora associated with the outer cell envelope.extrinsic ribonucleic acid (rna) can be isolated from a kcl extract of neurospora crassa conidial cell surface products. it is heterogeneous in size. the bulk of this rna travels as a broad band, trailing the 5.8s ribosomal marker rna on electrophoretic gels. the extrinsic rna, when denatured, exhibites several discrete lengths between 50,000 and 130,000 daltons. melting profiles confirm the heterogeneity of the rna and indicate that 58% of the bases are involved in hydrogen bonding. analyses of ...1977137232
characterization of qa-2 mutants of neurospora crassa by genetic, enzymatic, and immunological techniques.genetic and complementation mapping studies using 20 qa-2 mutants defective for catabolic dehydroquinase indicate that the qa-2 gene encodes a single polypeptide chain and is the structural gene for catabolic dehydroquinase, a 220,000-molecular-weight protein composed of identical 10,000-molecular-weight subunits. many qa-2 mutants are capable of reversion, but no evidence has yet been obtained for nonsense mutations in this gene. the biochemical consequences of the mutations in two complementin ...1977137228
[adenine uptake in neurospora crassa mycelium].the uptake of 8-c14-adenine in n. crassa strain lindegren (+) was studied. the ability of n. crassa cells to uptake adenine from the medium reaches maximum at the very beginning of the logarithmic stage of growth. adenine enters the mycelium against the concentration gradient. the uptake of adenine is maximal at 25-30 degrees c, ph 4,6-4,8, and adenine concentration in the medium about 2-15x10(-6) m. the entry of adenine into the cells follows normal michaelis-menten kinetics, the apparent km=0. ...197715650
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
nuclear mutations conferring oligomycin resistance in neurospora crassa.mutants of neurospora crassa have been isolated that are highly resistant to inhibition by oligomycin, an inhibitor of mitochondrial atpase activity. dixon plots (dixon, m., and webb, e.c. (1964) enzymes, 2nd ed, pp. 328-330, academic press, new york) of oligomycin inhibition curves of the parent strain and the resistant mutants are linear, indicating that oligomycin interacts at a single site within the atpase complex. the ki values obtained from the mutants vary from 150 to 900 times greater t ...1978149126
stability of messenger rna for nitrate reductase in neurospora crassa.a method has been developed to study the synthesis and decay of the messenger rna for nitrate reductase in neurospora crassa. glutamine prevents the synthesis of the mrna which appears to have a half-life of approximately 8.5 min.1978149559
5' cap methylation of homologous poly a(+) rna by a rna (guanine-7) methyltransferase from neurospora crassa. 1978151539
a meiotic uv-sensitive mutant that causes deletion of duplications in neurospora.the meiotic-3 (mei-3) mutant of neurospora crassa has several effects: (1) when homozygous, it almost completely blocks meiosis and ascospore formation, (2) it is sensitive to uv, (3) its growth is inhibited by histidine and, (4) it increases the instability of nontandem duplications. this was shown for duplications produced by five different rearrangements and was demonstrated by two different criteria. the effects on meiosis and duplication instability are expressed strongly at 25 degrees ; th ...197817248837
ageing of neurospora crassa. vii. accumulation of fluorescent pigment (lipofuscin) and inhibition of the accumulation by nordihydroguairetic acid.continuous administration of the antioxidant nordihydroguairetic acid to clones of the natural-death nutant or wild-type neurospora crassa growing on 5-fluorotryptophan not only alleviates the time-dependent deterioration of growth rate (senescence), but also inhibits the accumulation of a fluorescent pigment (lipofuscin), an end-product of lipid peroxidation. in the three model system of ageing in n. crassa that we have examined, it is now clear that massive accumulation of lipofuscin begins sh ...1978149885
an apparent connection between histidine, recombination, and repair in neurospora.two mutants of neurospora crassa, uvs-3 and mei-3, share four properties--uv sensitivity, inhibition by histidine, meiotic blockage when homozygous, and increased duplication instability (due to mitotic crossing over, to deletions or to both). the present paper shows that a third nonallelic mutant, uvs-6, exhibits the same four properties.--also, the instability of duplications in the absence of any uv-sensitive mutant is increased by the presence of histidine in the growth medium.1978149694
genetics and physiology of neurospora crassa glutamine auxotrophs.this work reports on the isolation and characterization of two glutamine auxotrophs in neurospora crassa. the mutations responsible for the glutamine-requiring phenotype were very closely linked, and one of them proved to be recessive to wild type. the mutations impaired the conversion of glutamic acid to glutamine and resulted in changes of both the activity and oligomeric structure of the enzyme glutamine synthetase.197826664
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
nuclear suppressors of the [poky] cytoplasmic mutant in neurospora crassa. iii. effects on other cytoplasmic mutants and on mitochondrial ribosome assembly in [poky].we have previously isolated six non-allelic, nuclear mutations (sui loci) that partially suppress the growth, respiratory and cytochrome abnormalities of the extranuclear [poky] mutant. a comparison of the mitochondrial ribosome profiles of suppressed and unsuppressed [poky] strains revealed that five of the six suppressors alleviate at least partially the deficiency of mitochondrial small ribosomal subunits that is associated with the [poky] genotype. six independently isolated group 1 extranuc ...1978149910
purification and characterization of quinate (shikimate) dehydrogenase, an enzyme in the inducible quinic acid catabolic pathway of neurospora crassa.the bifunctional enzyme quinate (shikimate) dehydrogenase (quinate: nad+ oxidoreductase, ec 1.1.1.24), which catalyzes the first reaction in the inducible quinic acid catabolic pathway of neurospora crassa, has been purified to homogeneity. the enzyme is a monomer of 41000 daltons with an s20,w = 2.94 s. however, electrophoresis under non-denaturing conditions revealed three protein species, which have both quinate and shikimate dehydrogenase activities. the enzyme, with a single binding site fo ...1978148913
regulation, purification, and properties of xanthine dehydrogenase in neurospora crassa.xanthine dehydrogenase (ec 1.2.1.37) is the first enzyme in the degradative pathway by which fungi convert purines to ammonia. in vivo, the activity is induced 6-fold by growth in uric acid. hypoxanthine, xanthine, adenine, or guanine also induce enzyme activity but to a lesser degree. immunoelectrophoresis using monospecific antibodies prepared against neurospora crassa xanthine dehydrogenase shows that the induced increase in enzyme activity results from increased numbers of xanthine dehydroge ...1978147274
role of metal cofactors in enzyme regulation. differences in the regulatory properties of the neurospora crassa nicotinamide adenine dinucleotide specific isocitrate dehydrogenase depending on whether mg2+ or mn2+ serves as divalent cation. 197825669
control of the activity of intracellular nucleases in neurospora crassa. 1978149909
purification and characterization of homogeneous assimilatory reduced nicotinamide adenine dinucleotide phosphate-nitrate reductase from neurospora crassa.neurospora crassa wild type sta4 nadph-nitrate reductase (nadph : nitrate oxidoreductase, ec 1.6.6.3) has been purified 5000-fold with an overall yield of 25--50%. the final purified enzyme contained 4 associated enzymatic activities: nadph-nitrate reductase, fadh2-nitrate reductase, reduced methyl viologen-nitrate reductase and nadph-cytochrome c reductase. polyacrylamide gel electrophoresis yielded 1 major and 1 minor protein band and both bands exhibited nadph-nitrate and reduced methyl violo ...197826408
small stable rna of neurospora crassa. 1978148000
cytochrome c-specific protein-lysine methyltransferase from neurospora crassa. purification, characterization, and substrate requirements. 1978203592
the nature of molybdenum-cofactor.in vitro assembly of neurospora crassa nadph-nitrate reductase (ec1.6.6.2) could be effected by combing the nitrate induced neurospora crassa mutant nit-1 with the extract of any known molybdenum-containing enzyme. the process involves the participation of a molybdenum-cofactor contributed by the molybdenum-enzyme fraction. this paper emphasizes two points: firstly, the indispensable role played by edta in the viability of mo-cofactor and secondly, the nature of mo-cofactor predicated by our pre ...1978150967
molecular alteration in a neurospora crassa morphological mutant and its phenocopy.a procedure using ion exchange chromatography has been developed to detect alterations in a polysaccharide produced by neurospora crassa. the polysaccharide, isolated from medium that has supported the growth of a culture, is highly responsive to the 3-methyl-2-benzothiazolinone hydrazone assay, indicating a high hexosamine content. the substance elaborated by wild-type n. crassa can be fractionated into two components that appear by rechromatography to be closely related. when isolated from mut ...1978148650
ultrastructural study of microcyclic macroconidiation in neurospora crassa.heat-shock of macroconidia of neurospora crassa at 46 degrees c followed by shift-down to 25 degrees c determines premature conidiogenesis. the nuclei and cytoplasmof heat-treated, swollen conidia contain spots of a dense material especially concentrated around the nucleolus in short time treated ones. in the first proconidium apically budding on the enlarged tip of the premature conidiophore, small vesicles are later seen lining the initially simple septum separating the proconidial units into ...1978148251
cyanide- and hydroxamate-resistant respiration in neurospora crassa.strain inl-89601 of neurospora crassa respires exclusively by means of the mitochondrial cytochrome chain. the respiration of this strain is entirely inhibited by cyanide or antimycin a, the classical inhibitors of cytochrome chain respiration. when this strain was grown in the presence of chloramphenicol, however, two additional terminal oxidases were detected. one of these oxidases is inhibited by substituted hydroxamic acids and has been described previously. the second oxidase was not inhibi ...1978147864
biosynthesis of glycogen in neurospora crassa. purification and properties of the udpglucose:glycogen 4-alpha-glucosyltransferase.the neurospora crassa glycogen synthase (udpglucose:glycogen 4-alpha-glucosyltransferase, ec 2.4.1.11) was purified to electrophoretic homogeneity by a procedure involving ultracentrifugation, deae-cellulose column chromatography, (nh4)2so4 fractionation and 3-aminopropyl-sepharose column chromatography. the final purified enzyme preparation was almost entirely dependent on glucose-6-p and had a specific activity of 6.9 units per mg of protein. the subunit molecular weight of the glycogen syntha ...197823841
mutations of the a mating-type gene in neurospora crassa.in neurospora, the mating-type locus controls both mating ( a + a is fertile) and heterokaryosis (a + a is incompatible). the two alleles appear stable: no novel fertility reactions have ever been reported, and attempts to separate fertility and heterokaryon incompatibility functions by recombination have been unsuccessful. in the present approach the locus was studied through a mutational analysis of heterokaryon incompatibility function. a selection system was used that detects vigorous (a + a ...197817248797
genetic and physiological characteristics of a slow-growing circadian clock mutant of neurospora crassa.a circadian clock mutant of neurospora crassa with a period length of about 25.8 hours (4 hr longer than wild type) has been isolated after mutagenesis of the band strain. this mutant, called frq-5, segregates as a single nuclear gene, maps near the centromere on linkage group iii, and is unlinked to four previously described clock mutants clustered on linkage group vii r (feldman and hoyle 1973, 1976). frq-5 differs from the other clock mutants in at least two other respects: (1) it is recessiv ...1978147796
the subunit structure of the arom multienzyme complex of neurospora crassa. evidence from peptide 'maps' for the identity of the subunits.evidence was obtained, from polyacrylamide-gel electrophoresis in the presence of urea and from peptide 'mapping' of specifically labelled cysteine-and methionine-containing peptides, that the two subunits of the arom multienzyme complex of neurospora crassa are chemically very similar and possibly identical.1978147081
structural features of normal and complemented forms of the neurospora isopropylmalate isomerase.the isopropylmalate isomerase (ec 4.2.1.33) of neurospora crassa is a globular protein consisting of a single polypeptide chain with a molecular weight of about 90,000. the isomerase cannot easily be freed of a contaminating protease which cleaves the enzyme into two major fragments, one of approximately 56,000 and the other 37,000 daltons. this suggests that the folded polypeptide chain may contain some hinge point or loop exposed on the surface which makes it susceptible to proteolytic attack. ...1978146703
regulation of isopropylmalate isomerase synthesis in neurospora crassa.the capacity to synthetize isopropylmalate isomerase (ec 4.2.1.33) by neurospora crassa increased during induction in the presence of cycloheximide but was inhibited by proflavine and other inhibitors of rna synthesis. turnover of the enzyme once formed appeared negligible, but the message (measured as enzyme-forming capacity) had a half-life of 4 to 8 min. a comparison of the kinetics of induction in the wild type and a newly isolated alpha-isopropylmalate-permeable strain suggested strongly th ...1978146702
induction and repression of nitrate reductase in neurospora crassa.synthesis of wild-type neurospora crassa assimilatory nitrate reductase is induced in the presence of nitrate ions and repressed in the presence of ammonium ions. effects of several neurospora mutations on the regulation of this enzyme are shown: (i) the mutants, nit-1 and nit-3, involving separate lesions, lack reduced nicotinamide adenine dinucleotide (nadph)-nitrate reductase activity and at least one of three other activities associated with the wild-type enzyme. the two mutants do not requi ...1978146700
mitochondrial adenosine triphosphatase of wild-type and poky neurospora crassa.we have compared the adenosine triphosphatase (atpase) activity of mitochondria prepared from wild-type neurospora crassa and from poky, a maternally inherited mutant known to possess defective mitochondrial ribosomes and reduced amounts of cytochromes aa3 and b. poky contains two distinct forms of mitochondrial atpase. the first is normal in its km for atp, specificity for nucleotides and divalent cations, ph optimum, cold stability, and sensitivity to inhibitors (oligomycin, n,n-dicyclohexyl c ...197824038
isolation and characterization of perithecial development mutants in neurospora.the isolation and characterization of mutants that block perithecial development in neurospora crassa are described. several classes of mutants have been isolated after uv mutagenesis, and those that block perithecial development when used as the female (protoperithecial) component of a cross have been further characterized. these mutants fall into 29 complementation groups. twelve of the 33 mutants block development at the protoperithecial stage; no other clustering of block points is observed. ...197817248793
purification of cytochrome oxidase from neurospora crassa and other sources. 1978213692
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
a comparative study of dna-induced transformants and spontaneous revertants of inositolless neurospora crassa.inositolless (inl-) neurospora crassa strains were treated with dna (allo-dna) of wild type n. crassa. hyphal fragments of a mycelial suspension of the n. crassa ragged inl- strain used as recipient in our transformation experiments were found to consist of units containing 100--1000 nuclei. in this strain the inositol-independent (inl+) nuclei appearing after dna treatment or by spontaneous reversion are present in the cytoplasm together with a large number of inl- nuclei. thus, both transforma ...1978161130
physiological response of neurospora conidia to freezing in the dehydrated, hydrated, or germinated state.this study concerned the response to freezing of neurospora crassa conidia in four different states: air-dry, hydrated in water, hydrated in vogel medium lacking only sucrose, or hydrated in complete vogel medium. all hydrated conidia were incubated in one of the above media for various times before freezing and were then washed and frozen in distilled water. viability was estimated by three techniques, and the agreement among them was good. hydration of air-dry conidia was found to be very rapi ...1978146455
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