Publications

TitleAbstractYear
Filter
PMID(sorted descending)
Filter
studies on the structure-function relationships of neurospora crassa pyruvate kinase: refolding and reactivation following denaturation in guanidine hydrochloride. 19816451460
magic-angle n-15 nmr study of nitrate metabolism of neurospora crassa. 19806451224
purification, properties and synthesis of delta-aminolaevulinate dehydratase from neurospora crassa.delta-aminolaevulinate dehydratase, the second and rate-limiting enzyme of the haem-biosynthetic pathway, was purified 300-fold from induced cultures of neurospora crassa. the native enzyme has a mol.wt. of about 350000, whereas the salt-treated enzyme after incubation at 37 degrees c for 10 min has a mol.wt. of about 232000. the mol.wt. of the subunit is about 38000. antibodies to the purified enzyme were raised in rabbits. by using radiolabelling and immunoprecipitation techniques it was shown ...19806451221
transcripts and processing patterns for the ribosomal rna and transfer rna region of neurospora crassa mitochondrial dna. 19816450763
genetic and biochemical characterization of d-arabinose dehydrogenase from neurospora crassa.d-arabinose dehydrogenase has been purified to homogeneity from wild-type neurospora crassa 74-a (fgsc 262) and from two colonial mutants, col-15a (fgsc 1391) and col-16a (fgsc 1349), found to contain more of the enzyme. the enzymes were characterized by measurement of several kinetic and physicochemical parameters. the enzymes were the same in all characteristics studied thus far. immunological studied performed with enzyme preparations from the three strains showed antigenic identity and indic ...19816450742
regulation of polyamine synthesis in relation to putrescine and spermidine pools in neurospora crassa.polyamine pools were measured under various conditions of high and low concentrations of cytosolic ornithine with the wild-type and mutant strains of neurospora crassa. in minimal medium, the wild-type strain has 1 to 2 nmol of putrescine and approximately 14 nmol of spermidine per mg (dry weight); no spermine is found in n. crassa. exogenous ornithine was found to cause a rapid, but quickly damped, increase in the rate of polyamine synthesis. this effect was greater in a mutant (ota) unable to ...19816450741
meiosis and ascospore genesis in neurospora.mcclintock [38] and singleton [69, 70] first described and documented the meiotic sequence in neurospora crassa with particular emphasis on the chromosome cycle. in recent years different methods have been used that yield greatly improved cytological preparations. this review provides an integrated description of normal meiosis and ascospore genesis for all eight-spored neurosporas with photographs of asci stained with iron-hematoxylin. in addition, maturing asci from crosses with selected mutan ...19806450683
biogenesis of glyoxysomes. synthesis and intracellular transfer of isocitrate lyase.biosynthesis of isocitrate lyase, a tetrameric enzyme of the glyoxysomal matrix, was studied in neurospora crassa, in which the formation of glyoxysomes was induced by a substitution of sucrose medium by acetate medium. 1. translation of neurospora mrna in reticulocyte lysates yields a product which has the same apparent molecular weight as the subunit of the functional enzyme. using n-formyl[35s]methionyl-trnafmet as a label, the translation product shows the same apparent size which indicates ...19806450681
synchronization of dna synthesis in neurospora crassa by 2'-deoxyadenosine and spore selection.2'-deoxyadenosine (2 mm), a dna inhibitor, was used to synchronize dna synthesis in cultures of neurospora crassa lys 3. the cultures recovered spontaneously from the inhibitor which had little or no effect o the synthesis of rna, protein or carbohydrate or on the specific growth rate of the mould. the degree of 'synchrony' of dna synthesis obtained with 2'-deoxyadenosine varied directly with the organism's specific growth rate when the latter was altered by temperature changes. a direct relatio ...19806450576
alkaline protease from neurospora crassa. purification and partial characterization.a simple purification procedure has been developed for the extracellular alkaline protease from neurospora crassa. key steps in the purification were: 1) the choice of gelatin as the protein inducer, which induces optimally at a much lower concentration than other commonly employed protein inducers; 2) heat treatment, during which the inducer is digested by the protease; and 3) a concentration step that eliminates the usual precipitation procedures and removes much of the digested protein induce ...19816450209
identification of the product of the major regulatory gene of the nitrogen control circuit of neurospora crassa as a nuclear dna-binding protein.the nitrogen regulatory circuit of neurospora crassa contains an entire set of unlinked structural genes which specify nitrogen catabolic enzymes. these genes are controlled as a group by a major regulatory gene, designated nit-2, which "turns on" their expression in a positive fashion. moreover, expression of these same structural genes is repressed when the cells contain sufficient nitrogen; the active repressor metabolite has been identified as glutamine. it has been suggested that the nit-2 ...19816450203
cellular events in growth and germination of giant conidia of neurospora crassa.during growth of conidia in 3.22 m ethylene glycol the increase in the number of the nuclei is proportional to the increase in volume only in the phase of maximum growth rate and is lower in the preceding and in the following periods of growth. dna synthesis similarly initiates later and decreases faster than protein synthesis. the dilution of ethylene glycol is followed by the germination of giant conidia, which is characterized by the absence of a lag phase, a high degree of synchrony and the ...19806450046
purification and characterization of histidyl-transfer rna synthetase from neurospora crassa.histidyl-trna synthetase (l-histidine:trnahis ligase (amp-forming), ec 6.1.1.21) has been purified 921-fold from crude extracts of lyophilized mycelia of neurospora crassa. sodium dodecyl sulfate gel electrophoresis at ph 8.9 of the purified enzyme yields one band with an apparent mr of 62 500. the estimated mr by sephadex gel filtration is 125 000. thus the native histidyl-trna synthetase of n. crassa is a dimer, composed of two identical subunits. the km values determined in the enzyme-catalyz ...19806449959
regulation and function of glutamate synthase in neurospora crassa. 19806449930
control of the flux in the arginine pathway of neurospora crassa. the flux from citrulline to arginine.the arginine pathway is a complex one, having many branch points and effector interactions. in order to assess the quantitative role of the various mechanisms that influence the flux in the pathway, the system was divided experimentally into two moieties by the introduction of a genetic block abolishing ornithine carbamoyltransferase activity. this normally produces citrulline from ornithine within the mitochondria. the endogenous citrulline supply was replaced by citrulline in the growth medium ...19806449928
evolutionary origins of vertebrate hormones: substances similar to mammalian insulins are native to unicellular eukaryotes.tetrahymena pyriformis, neurospora crassa, and aspergillus fumigatus that had been grown in simple defined media were extracted with acid ethanol by a classic method for recovering insulin from pancreas. after filtration of the extracts on sephadex g-50, distinct peaks of insulin immunoreactivity were recovered in the region typical of insulin. the gel-filtered material from the tetrahymena had reactivity in the pork insulin radioimmunoassay about equal to its reactivity in the insulin bioassay ...19806449704
deletion mutants of neurospora crassa mitochondrial dna and their relationship to the "stop-start" growth phenotype."stoppers" are a class of neurospora crassa extranuclear mutants characterized by gross deficiencies of cytochromes b and aa3 and an unusual growth phenotype which involves irregular periods of growth andnongrowth. in the present work, mtdnas from all four stopper mutants were found to contain deletions or insertions detectable by restriction enzyme analysis. [stp] mtdna consists predominantly of defective molecules which retain a 16-megadalton segment (ecori-1, -4, and -6) of wild-type mtdna (4 ...19806449700
a phenylalanine trna gene from neurospora crassa: conservation of secondary structure involving an intervening sequence.we have isolated and sequenced a trnaphe gene from neurospora crassa. hybridization analyses suggest that trnaphe is the only trna encoded on the cloned 5 kb dna fragment. the trnaphe gene contains an intervening sequence 16 nucleotides in length located one nucleotide 3' to the anticodon position. the trnaphe coding region of neurospora and yeast are 91% conserved, whereas their intervening sequences are only 50% identical. the pattern of sequence conservation is consistent with a proposed seco ...19806449692
the nucleotide sequence of phenylalanine trna from the cytoplasm of neurospora crassa.the phenylalanine trna from the cytoplasm of neurospora crassa has been purified and sequenced. the sequence is: pgcggguuuam2gcuca (n) gddgggagagcm22gpsicagacmugmaayapsim5cugaagm7gdm5cgugugtpsicgm1auccacacaaaccgcaccaoh. both in the nature of modified nucleotides which are present in this trna and in the overall sequence, this trna resembles more closely phenylalanine trnas of eukaryotic cytoplasm than those of prokaryotes. the sequence of this trna differs from those of the corresponding trnas o ...19806449691
studies on phospholipase activities in neurospora crassa mycelia.phospholipase a activity has been detected in mycelial homogenate of neurospora crassa. a submycelial fraction, obtained by differential centrifugation containing the highest specific activity of phospholipase a has been shown to contain ca. 66% phospholipase a and 34% phospholipase a activity along with lysophospholipase and degergent-stimulated phospholipase d activity. phospholipase a activity bound to n. crassa mycelia also has been observed.19806449646
regulation and glutamic acid decarboxylase during neurospora crassa conidial germination.glutamic acid decarboxylase (gad) from neurospora crassa was assayed in dormant and germinating conidia that had been permeabilized by toluene and methanol. n. crassa conidia contained 10 times the gad activity found in vegetativemycelia. during conidial germination, gad activity rapidly decreased to low levels before germ tubes appeared. gad activity in germinating conidia closely followed the decreasing rate of glutamic acid metabolism. inhibiting protein synthesis partially blocked the decrea ...19806449504
the isolation and characterization of mutants defective in nitrate assimilation in neurospora crassa.the isolation and characterization of mutants altered for nitrate assimilation in neurospora crassa is described. the mutants isolated can be subdivided into five classes on the basis of growth test that correspond to the growth patterns of existing mutants at six distinct loci. mutants with growth characteristics like those of nit-2, nit-3 and nit-6 are assigned to those loci on the basis of noncomplementation and lack of recombination. mutants that, from their growth patterns, appear to lack t ...19806449399
polyglutamylfolate synthesis in neurospora crassa: changes in pool size following growth in glycine- and methionine-supplemented media. 19806449176
eukaryotic dna segments capable of autonomous replication in yeast.a selective scheme is presented for isolating sequences capable of replicating autonomously in the yeast saccharomyces cerevisiae. yip5, a vector that contains the yeast gene ura3, does not transform a ura3 deletion mutant to ura+. hybrid yip5-escherichia coli dna molecules also fail to produce transformants. however, collections of molecular hybrids between yip5 and dna from any of six eukaryotes tested (s. cerevisiae, neurospora crassa, dictyostelium discoideum ceanhorabditis elegans, drosophi ...19806449009
a 15n nmr study on d-lysine metabolism in neurospora crassa.the metabolic relationship of d-lysine, l-lysine, and l-pipecolic acid has been investigated in neurospora crassa. kinetic experiments show that radioactivity from d-lysine is efficiently incorporated into l-pipecolic acid and that this metabolite is converted to l-lysine. the alpha-amino group from d-[alpha-15n]lysine is lost in the course of its conversion to l-pipecolic acid and is trapped by pyruvate and alpha-keto glutarate to give l-[alpha-15n]alanine and l-[alpha-15n]glutamic acid. these ...19806448848
synthesis of carnitine from epsilon-n-trimethyllysine in post mitochondrial fractions of neurospora crassa. 19806448601
regulation of cytoplasmic and mitochondrial leucyl-transfer ribonucleic acid synthetases in neurospora crassa.the production of cytoplasmic leucyl-transfer ribonucleic acid synthetase activity was found to be reciprocally proportional to that of the corresponding mitochondrial enzyme during logarithmic growth of strains of neurospora crassa with normal mitochondria. in the presence of cni-3 mutant mitochondria, production of mitochondrial enzyme activity was greatly increased whereas cytoplasmic enzyme production remained constant. the effect of cni-3 on the yield of the two enzyme activities indicated ...19806448249
repression of nitrate reductase activity and loss of antigenically detectable protein in neurospora crassa.experiments were performed to determine whether conditions which cause the rapid loss of nitrate reductase activity in neurospora crassa mycelia were accompanied by the loss of antigenically detectable nitrate reductase protein. when mycelia with nitrate reductase activity were transferred to ammonia media, there was a rapid loss in the reduced nicotinamide adenine dinucleotide-nitrate reductase activity plus the parallel loss of the reduced nicotinamide adenine dinucleotide-diaphorase and the r ...19806448248
novel features in the genetic code and codon reading patterns in neurospora crassa mitochondria based on sequences of six mitochondrial trnas.we report the sequences of neurospora crassa mitochondrial alanine, leucine(1), leucine(2), threonine, tryptophan, and valine trnas. on the basis of the anticodon sequences of these trnas and of a glutamine trna, whose sequence analysis is nearly complete, we infer the following: (i) the n. crassa mitochondrial trna species for alanine, leucine(2), threonine, and valine, amino acids that belong to four-codon families (gcn, cun, acn, and gun, respectively; n = u, c, a, or g) all contain an unmodi ...19806447871
guanosine metabolism in neurospora crassa.two aspects of guanosine metabolism in neurospora have been investigated. (a) the inability of adenine mutants (blocked prior to imp synthesis) to use guanosine as a nutritional supplement; and (b) the inhibitory effect of guanosine on the utilization of hypoxanthine as a purine source for growth by these mutants. studies on the utilization of guanosine indicated that the proportion of adenine derived from guanosine may be limiting for the growth of adenine mutants. in wild type, adenine is prod ...19806447534
stimulation of the alternative oxidase of neurospora crassa by nucleoside phosphates.the alternative-oxidase-mediated succinate oxidase activity of neurospora crassa decreases drastically when mitochondria are fractionated into submitochondrial particles or treated with deoxycholate. the activity, however, can be completely restored in the presence of nucleoside 5'-monophosphates. the purine nucleoside 5'-monophosphates are more effective than the pyrimidine homologues. 5'-gmp gives a 10-fold stimulation of the alternative-oxidase-mediated succinate oxidase activity in submitoch ...19806447503
effects of cytochalasins on neurospora crassa. i. growth and ultrastructure. 19806447315
secondary structure predictions for the nad-specific glutamate dehydrogenase of neurospora crassa.from the amino acid sequences of the three known fragments of the nad-specific glutamate dehydrogenase of neurospora crassa, the secondary structures have been predicted from the rules of chou and fasman (chou, p.y., and fasman, g.d. (1979) biophys. j. 26, 367-384). comparison of these structures with those calculated for bovine glutamate dehydrogenase has shown that in the regions of homologous sequences containing identified functional regions, there is considerable homology of structure. from ...19806447152
nad-specific glutamate dehydrogenase of neurospora crassa. limited action of trypsin and the presence of two distinct domains. 19806447151
nicotinamide adenine dinucleotide-specific glutamate dehydrogenase of neurospora crassa. isolation and sequences of several cyanogen bromide peptides from the nh2-terminal portion of the peptide chain.previous studies of the amino acid sequence of the nad-specific glutamate dehydrogenase of neurospora crassa (ec 1.4.1.2) resulted in the assignments of peptides to four fragments, the longest being the cooh-terminal 669 residues of the protein. a further study of peptides derived by cyanogen bromide cleavage by different separation methods has yielded additional peptides that have provided new information concerning the sequence and has given overlaps of previously known sequences. this has per ...19806447150
physiological and regulatory properties of the general amino acid transport system of neurospora crassa.the fundamental properties of the general amino acid transport system of neurospora crassa were investigated in the conidial stage of the life cycle. the transport activity was found to be under genetic control, and an isogenic set of mutants deficient for the neutral, basic, or general amino acid transport systems and combinations thereof was constructed and used for analyzing the properties specific to the general permease. amino acid transport by this system was found to be a carrier-mediated ...19806447141
inositol-limited growth, repair, and translocation in an inositol-requiring mutant of neurospora crassa.the biochemical consequences of inositol limitation in an inositol auxotroph of neurospora crassa have been examined as a means of disclosing the cellular role of inositol. the cellular levels of inositol in the inl mutant were proportional to the concentration of inositol in the growth medium whereas inositol phosphate levels remained relatively constant at about 0.1 mumol/g (dry weight). after 72 h of growth, about 57-fold more protein per milligram (dry weight) was released by the mutant grow ...19806447140
studies of the structure--function relationships of neurospora crassa pyruvate kinase: interaction with blue dextran--sepharose and cibacron blue 3g-a.blue dextran--sepharose and cibacron blue 3g-a interact with pyruvate kinase of neurospora crassa. the enzyme is readily released from the substituted sepharose column by elution with 0.17 m potassium phosphate buffer (ph 7.9), or 2 mm fructose 1,6-diphosphate (fdp), but not with either of the substrates, adp and phosphoenolpyruvate (pep), at 2 mm. cibacron blue 3g a is a noncompetitive inhibitor of pyruvate kinase with respect to both substrates. it appears to compete with the allosteric effect ...19806446967
protein synthesis by hybrid ribosomes reconstructed from rabbit reticulocyte ribosomal core-particles and amphibian or fungal split-proteins.it was shown that high-salt (2.75 m-nh4cl/69mm-mgcl2) shock treatment at 0 degrees c of the larger subparticles (l-subparticles) of rabbit, xenopus laevis and neurospora crassa cytoplasmic ribosomes yielded split-protein fractions that were not only functionally equivalent but also interchangeable. thus, although the remaining core-particles were inactive in both the puromycin reaction and in poly(u)-directed polyphenylalanine synthesis, activity was restored when they were combined with either ...19806446904
substrate kinetics of the alternative oxidase of neurospora crassa.the kinetics of the succinate oxidation by cyanide-sensitive and cyanide-insensitive submitochondrial particles of neurospora crassa cells suggest that both respiratory pathways use the same complex ii. this is confirmed by comparing the kinetics of the reductase activities of the isolated succinate-ubiquinone oxidoreductase (complex ii) of cyanide-sensitive and cyanide-insensitive cells respectively. no alternative-oxidase activity was found to be associated with the isolated complex ii of cyan ...19806446900
purification and characterization of uricase, a nitrogen-regulated enzyme, from neurospora crassa. 19806446884
mutagenesis at the ad-3a and ad-3b loci in haploid uv-sensitive strains of neurospora crassa. ii. comparison of dose-response curves for inactivation and mutation induced by uv.uv-induced inactivation and induction of mutations at the ad-3a and ad-3b loci of neurospora crassa have been compared among 7 different uv-sensitive strains and a standard wild-type strain. the 7 strains show varying degrees of sensitivity to uv-induced inactivation, with the relative sensitivity being: uvs-2 greater than uvs-3 greater than uvs-4 greater than uvs-6 greater than upr-1 greater uvs-5 greater than uvs-1. studies on the induction of ad-3 mutants by uv show that the 2 excision-repair ...19806446682
mutagenesis at the ad-3a and ad-3b loci in haploid uv-sensitive strains of neurospora crassa. i. development of isogenic strains and spontaneous mutability.7 different mutations that confer sensitivity to inactivation by ultraviolet light have been investigated for their effect on spontaneous mutation at the ad-3a and ad-3b loci in haploid strains of neurospora crassa. the collection and development of strains isogenic to wild-type 74a is described as well as experiments to determine the effects of each mutation on the spontaneous ad-3 mutation frequency. 6 of the strains showed spontaneous ad-3 mutant frequencies not significantly different from t ...19806446681
role of lipids in the neurospora crassa membrane: iii. lipid composition and phase transition properties of the plasma membrane, and its components. 19806446606
heat-induced changes in respiratory pathways and mitochondrial structure during microcycle conidiation of neurospora crassa.changes in both respiratory pathways and mitochondrial structure of neurospora crassa occurred under conditions of microcycle conidiation. upon heat-treatment at 46 degrees c, conidia developed a highly cyanide-insensitive, hydroxamate-sensitive respiration associated with morphological alterations in mitochondrial membranes; such changes were time-dependent. when heat-treated conidia were shifted down to 25 degrees c, the alternate, hydroxamate-sensitive respiration decreased significantly, par ...19806446266
[influence of cultivation temperature on the development of functionally active photoregulatory systems in cells of neurospora crassa and physarum polycephalum].illumination with a visible light is known to induce accumulation of colored carotenoid pigments in mycelial cells on neurospora crassa and sporulation of starved macroplasmodia of physarum polycephalum. in both microorganisms, the temperature, at which they are cultivated in the dark, controls manifestation of the photoregulation processes in the cells subsequently exposed to light. the maximal rate of photoinduced accumulation of carotenoids in n. crassa is observed, when the cells are grown i ...19806446087
the extraction of inositol-containing phospholipids and phosphatidylcholine from saccharomyces cerevisiae and neurospora crassa.by use of fungi grown in the presence of [3h]-inositol and [14c]choline, we have explored methods for the quantitative extraction of inositol-containing phospholipids and phosphatidylcholine. slightly alkaline mixtures of both ethanol-water and ethanol-diethylether-water at elevated temperatures were shown to effectively extract these lipids from intact saccharomyces cerevisiae and neurospora crassa. some previously published procedures fail to completely extract to very polar phosphoinositol-co ...19806445928
basic amino acids and inorganic polyphosphates in neurospora crassa: independent regulation of vacuolar pools.at least 78%, and perhaps all, of inorganic polyphosphate is shown to be contained within the vesicles (vacuoles) of neurospora crassa, where over 97% of the soluble arginine, lysine, and ornithine pools are known to accumulate. furthermore, synthetic polyphosphate can concentrate arginine up to 400-fold from dilute (0.01 mm) solutions in equilibrium dialysis. for these reasons and because the molar ratio of basic amino acids and polyphosphate phosphorus is approximately 1, we tested the hypothe ...19806445898
fructose transport in neurospora crassa.a specific fructose uptake system (km = 0.4 mm) appeared in neurospora crassa when glucose-grown mycelia were starved. fructose uptake had kinetics different from those of intramycelial fructose phosphorylation, and uptake appeared to be carrier mediated. the only sugar which competitively inhibited fructose uptake was l-sorbose (ki = 9 mm). glucose, 2-deoxyglucose, mannose, and 3-o-methyl glucose were noncompetitive inhibitors of fructose uptake. incubation of glucose-grown mycelia with glucose ...19806445895
mutagenic activity of tetryl, a nitroaromatic explosive, in three microbial test systems.the military explosive n-methyl-n,2,4,6-tetranitroaniline (tetryl) is a direct acting mutagen in three microbial mutagenicity test systems at concentrations as low as 5 microgram/ml. in two of these systems (neurospora crassa and salmonella typhimurium) it caused base-pair substitution reversions. in the third (saccharomyces cerevisiae d4) it caused mitotic gene conversions at two loci. three nonaromatic explosives (petn, rdx, hmx) did not exhibit mutagenic activity in the ames salmonella test. ...19806445609
effects of ph on the mutagenicity of sodium azide in neurospora crassa and salmonella typhimurium.sodium azide at various ph values did not cause a significant increase in the frequency of forward mutation above the control frequency at the adenine-3 (ad-3) region in resting conidia and in conidia from growing cultures of heterokaryons 12 and 59 of neurospora crassa. conidia from ad-3 mutants were plated with sodium azide at various ph values, and no obvious increase in reverse mutation above the controls was observed. data are presented showing that sodium azide at ph 3 is inactivating coni ...19806445502
nuclear division cycle in neurospora crassa hyphae under different growth conditions.treatment with picolinic acid blocked neurospora crassa nuclei in g1, and recovery from the treatment allowed a synchronous wave of deoxyribonucleic acid synthesis to occur. nuclei, which appeared as compact globular bodies during the period of blockage, assumed a ring shape during the following s phase, which was also maintained in the g2 phase. the proportion of compact globular nuclei was much higher in hyphae growing at lower rates, whereas that of ring nuclei increased when the hyphae were ...19806445357
purine biosynthesis and its regulation in neurospora crassa.purine biosynthesis and its regulation was studied in neurospora crassa by the incorporation of label from [14c]formate into total cellular purines. in general, the purine biosynthesis resulted in slightly more cellular guanine than adenine nucleotides. the acid-soluble pool however, contained more adenine compounds than guanine. exogenous adenine was found to be an effective regulatory of the proximal steps of the de novo biosynthesis, while both adenine and guanine were equally effective in re ...19806445209
3-amino-1,2,4-triazole is an inhibitor of protein synthesis on mitoribosomes in neurospora crassa.the effects of the herbicide, 3-amino-1,2,4-triazole, an inhibitor of heme synthesis in rat liver, have been examined in the mold neurospora crassa. the drug is a potent inhibitor of the growth of the mold and produces biochemical changes identical to those produced by chloramphenicol. 3-amino-1,2,4-triazole, like chloramphenicol, is a direct and specific inhibitor of protein synthesis on mitoribosomes. a decrease in the levels of mitochondrial proteins which are completely or partly made on mit ...19806445208
characterization of protoporphyrin as the physiological regulatory of delta-aminolevulinate dehydratase in neurospora crassa. 19806445207
characterization and regulation of galactose transport in neurospora crassa.two galactose uptake systems were found in the mycelia of neurospora crassa. in glucose-grown mycelia, galactose was transported by a low-affinity (km = 400 mm) constitutive system which was distinct from the previously described glucose transport system i (r. p. schneider and w. r. wiley, j. bacteriol. 106:479--486, 1971). in carbon-starved mycelia or mycelia incubated with galactose, a second galactose transport activity appeared which required energy, had a high affinity for galactose (km = 0 ...19806444943
the hexokinases from wild-type and morphological mutant strains of neurospora crassa. 19806444874
n,n'-dicyclohexylcarbodiimide binds specifically to a single glutamyl residue of the proteolipid subunit of the mitochondrial adenosinetriphosphatases from neurospora crassa and saccharomyces cerevisiae.the n,n'-dicyclohexylcarbodiimide-binding proteolipid subunit of the mitochondrial adenosinetriphosphatases (atp phosphohydrolase, ec 3.6.1.3) of neurospora crassa and saccharomyces cerevisiae were purified from mitochondria incubated with the radioactively labeled inhibitor. the specifically labeled subunit was cleaved with cyanogen bromide and n-bromosuccinimide, and the resultant fragments were separated by gel chromatography in the presence of 80% (vol/vol) formic acid. the n,n'-dicyclohexyl ...19806444724
copper metallothionein, a copper-binding protein from neurospora crassa.copper is an essential constituent of many proteins which participate in biologically important reactions. in contrast to iron, where different metal storage and transport proteins have been extensively characterised, the existence of copper proteins serving such functions is still a matter of controversy. studies on the biosynthesis of tyrosinase from neurospora crassa with respect to the copper status of this fungus have shown that this organism accumulates copper with the concomitant synthesi ...19806444697
nadh-dependent glutamate synthase and nitrogen metabolism in neurospora crassa. 19806444511
circadian rhythms in neurospora crassa: oligomycin-resistant mutations affect periodicity.nuclear mutations conferring resistance to oligomycin, a mitochondrial inhibitor, shorten the period of the circadian conidiation rhythm of neurospora crassa from the normal 21.5 hours to 18 to 19 hours and slow the linear growth rate by 30 percent. these olir mutations map very close to frq, a locus at which mutations affecting periodicity have been previously obtained. the possibilities are discussed that mitochondria are involved in circadian rhythm generation and that certain period-length m ...19806444467
control of arginine metabolism in neurospora: flux through the biosynthetic pathway.the flux into the arginine biosynthetic pathway of neurospora crassa was investigated using a mutant strain lacking the ornithine-degrading enzyme ornithine aminotransferase (ec 2.6.1.13). flux was measured by the increase in the sum of the radioactivity (derived from [14c]glutamic acid) in the ornithine pool, the arginine pool, and arginine incorporated into proteins. complete cessation of flux occurred immediately upon the addition of arginine to the growth medium. this response occurred prior ...19806444407
effect of carbon source on enzymes and metabolites of arginine metabolism in neurospora.the levels of enzymes and metabolites of arginine metabolism were determined in exponential cultures of neurospora crassa grown on various carbon sources. the carbon sources decreased in effectiveness (as determined by generation times) in the following order: sucrose, acetate, glycerol, and ethanol. the basal and induced levels of the catabolic enzymes, arginase (ec 3.5.3.1) and ornithine transaminase (ec 2.6.1.13), were lower in mycelia grown on poor carbon sources. arginase was more sensitive ...19806444405
genome organization and characterization of the repetitive and inverted repeat dna sequences in neurospora crassa. 19806444301
demonstration of de novo synthesis of neurospora crassa nitrate reductase during induction. 19806444300
genetic toxicology of ethylenediaminetetraacetic acid (edta).edta and its salts have a number of applications in medicine and pharmacy. edta is used to remove calcium from the human body, and serves as an anticoagulant and as a detoxicant after poisoning by heavy metals. it is often used in analytical chemistry for complexometric titrations and many other purposes. because the compound is of rather low toxicity, it is used as a food additive to bind metal ions. edta affects the inhibition of dna synthesis in primary cultures of mammalian cells. this may b ...19836406880
dna polymerases, deoxyribonucleases, and recombination during meiosis in saccharomyces cerevisiae.we utilized strains of saccharomyces cerevisiae that exhibit high efficiency of synchrony of meiosis to examine several aspects of meiosis including sporulation, recombination, dna synthesis, dna polymerase i and ii, and mg2+-dependent alkaline dnases. the kinetics of commitment to intragenic recombination and sporulation are similar. the synthesis of dna, as measured directly with diphenylamine, appears to precede the commitment to recombination. both dna polymerase i and ii activities and tota ...19846396507
evidence for two control genes regulating expression of the quinic acid utilization (qut) gene cluster in aspergillus nidulans.the first three steps in quinic acid degradation in aspergillus nidulans are catalysed by highly inducible enzymes encoded by a gene cluster regulated by an adjacent control region. analysis of two non-inducible mutants has been done in diploid strains, where quta8 is recessive and all three enzyme activities are fully induced in heterozygous quta8/quta+ diploids. in contrast, quta4/quta+ heterozygous diploids show semi-dominance of the mutant allele, giving markedly diminished growth on quinic ...19846374025
distribution of a corticosteroid-binding protein in candida and other fungal genera.using [3h]corticosterone as a probe, corticosteroid-binding protein (cbp) was detected in eight out of eight isolates of candida albicans, of both a and b serotypes. the apparent dissociation constant (kd) in the various isolates ranged between 8 and 19 nm; the binding capacity varied from 122 to over 2400 fmol (mg cytosol protein)-1. there was no correlation between the amount or affinity of cbp and isolate virulence for murine hosts. further analysis revealed demonstrable cbp in six out of six ...19836355389
identification of an iron uptake system specific for coprogen and rhodotorulic acid in escherichia coli k12.with the lac operon fusion technique, mutants were isolated in two genes that specify two outer membrane proteins designated fhue (76 k) and fiu (83 k). the synthesis of both proteins was increased under low iron growth conditions. the fhue-protein was shown to be necessary for iron uptake via coprogen, an iron chelator produced by certain fungi, e.g. neurospora crassa. in addition to fhuee the genes fhucdb, tonb and exbb were necessary for iron coprogen uptake. the gene fhue was mapped between ...19836353165
mutagenicity screening with fungal systems.several fungal species have been used for mutagenicity screening: aspergillus nidulans, saccharomyces cerevisiae, and neurospora crassa. the eukaryotic nature of these organisms with typical chromosomes in a nucleus and their mitotic and meiotic mode of nuclear division have been the basis for the development of test systems that cover the full spectrum of genetic changes typical for eukaryotes. it is possible to detect simple point mutations and also grosser structural chromosomal alterations. ...19836349475
the imported preprotein of the proteolipid subunit of the mitochondrial atp synthase from neurospora crassa. molecular cloning and sequencing of the mrna.the proteolipid subunit of the mitochondrial atp synthase from neurospora crassa is an extremely hydrophobic protein of 81 amino acid residues, which is imported into mitochondria as a precursor of mol. wt. 15 000. the primary structure of the imported form has now been determined by isolating and analyzing cdna clones of the preproteolipid mrna. an initial cdna clone was identified by hybridizing total polyadenylated rna to pooled cdna recombinant plasmids from an ordered clone bank and subsequ ...19826329691
the nuclear-coded subunits of yeast cytochrome c oxidase. iii. identification of homologous subunits in yeast, bovine heart, and neurospora crassa cytochrome c oxidases.sequences for the nh2-terminal halves of subunits iv, v, vi, vii, and viia from yeast cytochrome c oxidase have been determined and used to identify homologous subunits in bovine heart and neurospora crassa cytochrome c oxidases. in conjunction with the complete sequence of subunit viii (s. d. power, m. a. lochrie , t. e. patterson, and r. o. poyton (1984) j. biol. chem. 259, 6571-6574), we have been able to identify counterparts to yeast subunits iv, v, vi, and viii in bovine heart cytochrome c ...19846327686
on the origin of chromosomal aberrations in human peripheral lymphocytes in vitro. i. experiments with neurospora endonuclease and polyethylene glycol.post-treatment of mutagen-treated human peripheral lymphocytes with a single-strand specific endonuclease from neurospora crassa leads to a significant elevation of the rate of structural chromosomal aberrations. our results indicate that dna double-strand breaks (dsb) are ultimate lesions for the formation of chromosomal aberrations in the g1 and g2 phase of the cell cycle and probably also in the s-phase. post-treatment of x-irradiated g2 cells with polyethylene glycol (peg) leads to an elevat ...19846327498
isolation and manipulation of genes coding for energy-transducing enzymes from neurospora crassa and escherichia coli. 19846327431
subunit 1 of cytochrome oxidase from neurospora crassa: nucleotide sequence of the coding gene and partial amino acid sequence of the protein.a partial protein sequence (223 residues) of cytochrome oxidase subunit 1 from neurospora crassa has been established. the nucleotide sequence of a cloned mitochondrial dna segment, including the structural gene coding for the mature subunit 1 (co i locus) was determined. in contrast to the situation in yeast, the co i locus in n. crassa is not interrupted by long intervening sequences. a polypeptide of 555 residues with a mol. wt. of 61 000 has been deduced from the reading frame established by ...19826327266
specific regulatory interconnection between the leucine and histidine pathways of neurospora crassa.leucine auxotrophs of neurospora fall into two discrete categories with respect to sensitivity to the herbicide, 3-amino-1,2,4-triazole. the pattern of resistance corresponds exactly to the ability to produce the leucine pathway control elements, alpha-isopropylmalate and the leu-3 product. an analysis of the regulatory response of the production of enzymes of histidine biosynthesis to alpha-isopropylmalate implicates the control elements of the leucine pathway as important components of the mec ...19846325383
nucleotide sequence of the cloned mrna and gene of the adp/atp carrier from neurospora crassa.a cdna complementary to the mrna of the adp/atp carrier from neurospora crassa was identified among ordered cdna clones by hybridizing total polyadenylated rna to pools of 96 cdna recombinant plasmids and subsequent cell-free translation of hybridization-selected mrna. further carrier cdnas were found by colony filter hybridization at a frequency of 0.2-0.3%. the gene of the carrier was cloned and isolated on a 4.6-kbp ecori fragment of total neurospora dna, and the start of the mrna was determi ...19846325169
nucleotide sequence of saccharomyces cerevisiae genes trp2 and trp3 encoding bifunctional anthranilate synthase: indole-3-glycerol phosphate synthase.saccharomyces cerevisiae anthranilate synthase:indole-3-glycerol phosphate synthase is a multifunctional hetero-oligomeric enzyme encoded by genes trp2 and trp3. trp2, encoding anthranilate synthase component i, was cloned by complementation of a yeast trp2 mutant. the nucleotide sequence of trp2 as well as that of trp3 were determined. the deduced anthranilate synthase component i primary structure from yeast exhibits only limited similarity to that of the corresponding escherichia coli subunit ...19846323449
survey, purification, and properties of sugar phosphate phosphohydrolase among microorganisms.sugar phosphate phosphohydrolase was purified approximately 500- to 600-fold to apparent homogeneity from escherichia coli b, escherichia coli c, escherichia coli var. communior, escherichia acidilactici, enterobacter aerogenes, neisseria meningitidis, and saccharomyces cereviseae. the molecular weights of the enzyme as estimated by gel filtration ranged from 97 x 10(3) to 101 x 10(3). the enzyme was composed of two subunits with the same molecular weight which ranged from 50 x 10(3) to 52 x 10( ...19836322944
phospholipase-induced crystallization of channels in mitochondrial outer membranes.when outer membranes from neurospora crassa mitochondria are treated with low levels of phospholipase a2 under continuous dialysis, two-dimensional crystalline arrays of the pore protein component of these membranes are formed.19846322311
molecular analysis of the neurospora qa-1 regulatory region indicates that two interacting genes control qa gene expression.the qa-1 regulatory region controls the expression of the three structural genes required for the early reactions in quinic acid catabolism in neurospora crassa. genetic analysis previously identified two types of noninducible qa-1 mutants, qa-1s and qa-1f, which mapped in separate non-overlapping regions. these mutations were originally interpreted as defining separate domains of a single regulatory protein. this communication describes the further genetic and physical characterization of the q ...19846322189
isolation of complex iii from various mitochondria. comparison of the structural and functional properties of the preparations from beef heart, calf liver and neurospora crassa.active complex iii was isolated by an improved procedure from beef heart mitochondria, from neurospora crassa mitochondria and for the first time from mitochondria originating from mammalian tissue other than heart, i.e. calf liver. the described procedure consists of differential extraction of the respective mitochondria, hydroxyapatite chromatography and, finally, either gel- or affinity chromatography. the preparations contain the well known prosthetic groups, i.e. 6-8 mumol b-type heme, 3-4 ...19836321316
genetically determined conidial longevity is positively correlated with superoxide dismutase, catalase, glutathione peroxidase, cytochrome c peroxidase, and ascorbate free radical reductase activities in neurospora crassa.aging of post-mitotic cells, the conidia, of neurospora crassa is defined as the time-dependent loss of viability under a constant laboratory environment which probably resembles the organism's tropical habitat; namely, at 30 degrees c, 85-100% relative humidity under white light. median lifespan is defined as the age at which survival of a conidial population has declined to 50% of that of a fully viable population at birth. a collection of short (age-) and long-lived (age+) mutants were previo ...19846319835
isolation of dna from filamentous fungi and separation into nuclear, mitochondrial, ribosomal, and plasmid components.a general procedure for purifying and efficiently separating four types of dna from filamentous fungi has been developed. the protocol involves (i) disruption of mycelial cells by blending in liquid nitrogen followed by suspension of cell contents in buffer containing high concentrations of protease and edta; (ii) deproteinization with phenol; (iii) cesium chloride/bisbenzimide density gradient centrifugation to separate nuclear dna, mitochondrial dna, and ribosomal dna; and (iv) agarose gel ele ...19836318603
isolation and properties of the porin of the outer mitochondrial membrane from neurospora crassa. 19836318030
biogenesis of cytochrome c in neurospora crassa. 19836318029
transient kinetic studies of neurospora crassa cytochrome c oxidase.the reaction of neurospora crassa cytochrome c oxidase with co was studied by flash-photolysis and rapid-mixing experiments, leading to the determination of the association and dissociation rate constants (7 x 10(4) m-1 x s-1 and 0.02s-1 respectively). pre-steady-state kinetic investigations of the catalytic properties of the enzyme showed that under proper conditions neurospora cytochrome c oxidase can be 'pulsed', i.e. activated, like the mammalian enzyme. the 'pulsed' species is spectroscopic ...19836316928
point mutations and dna rearrangements 5' to the inducible qa-2 gene of neurospora allow activator protein-independent transcription.expression of the qa-2 gene of neurospora crassa normally requires a functional activator protein encoded by qa-1f. twelve transcriptional mutants of the qa-2 gene have been isolated in qa-1f- strains, and these allow partial expression of qa-2 (1-45% of induced wild type) in the absence of functional activator protein. all 12 mutants have been characterized by genomic (southern) blot hybridization and the dnas of 5 have been cloned and sequenced. eight mutations consist of large dna rearrangeme ...19836316356
preparation of highly purified mitochondria of neurospora crassa on a percoll gradient.mitochondria isolated from neurospora crassa were purified by centrifugation in a percoll density gradient. enzyme activities and cytochrome differential spectra revealed a high purity of the mitochondria. as compared with a crude mitochondrial fraction the purified mitochondria exhibited a high respiratory activity and a fine adp/o ratio. electrophoresis of nucleic acids demonstrated the absence of cytoplasmic rrna.19836315550
cytochrome oxidase subunit 2 gene in neurospora crassa mitochondria.the nucleotide sequence of the cytochrome oxidase subunit 2 (cox2) gene has been obtained from cloned mitochondrial dna segments of neurospora crassa. the coding sequences have been identified on the basis of protein sequence homology with the subunit 2 of cytochrome oxidase from yeast and man. the postulated precursor of the n. crassa subunit 2 protein is 250 amino acids long, with a molecular weight of 28,700. as in the trna and rrna genes, the subunit 2 gene is flanked by g + c-rich palindrom ...19836313689
purification and properties of single strand dna-binding endo-exonuclease of neurospora crassa.single strand dna-binding endo-exonucleases purified from mitochondria, vacuoles, or a mixture of these organelles had the same high specific single strand dnase activity (910 mumol of nucleotides/min/mg), and each contained a polypeptide of mr = 31,000-33,000 which was found to be active by sodium dodecyl sulfate-dna-gel electrophoresis. the properties of the three preparations were identical in all respects tested. the enzyme showed distributive endonuclease activity with single strand dna, bu ...19836311833
isolation and characterization of the neurospora crassa endoplasmic reticulum.the endoplasmic reticulum from neurospora crassa was identified by monitoring the activity of the putative enzyme marker phosphatidylcholine glyceride transferase. after differential centrifugation of a cell homogenate, phosphatidylcholine glyceride transferase activity initially copurified with plasma membrane h+-atpase. however, isopycnic centrifugation of the whole-cell homogenate on a linear sucrose gradient separated the two enzyme activities into different fractions. the lighter membrane f ...19836311800
repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities in neurospora crassa.two molecular species of repressible extracellular phosphodiesterases showing cyclic 2',3'- and cyclic 3',5'-nucleotide phosphodiesterase activities were detected in mycelial culture media of wild-type neurospora crassa and purified. the two molecular species were found to be monomeric and polymeric forms of an enzyme constituted of identical subunits having molecular weights of 50,000. this enzyme had the same electrophoretic mobility as repressible acid phosphatase. the enzyme designated repre ...19836311798
the genes coding for histone h3 and h4 in neurospora crassa are unique and contain intervening sequences.sequences coding for histone h3 and h4 of neurospora crassa could be identified in genomic digests with the use of the corresponding genes from sea urchin and x. laevis as hybridization probes. a 2.6 kb hindiii-generated n. crassa dna fragment, showing homology with the heterologous histone h3-gene probes was cloned in a charon 21a vector. using dna from this clone as a homologous hybridization probe a 6.9 kb sali-generated dna fragment was isolated which in addition to the histone h3-gene also ...19836310494
receptor sites involved in posttranslational transport of apocytochrome c into mitochondria: specificity, affinity, and number of sites.assembly of cytochrome c involves a series of steps: synthesis of apocytochrome c on free ribosomes, specific binding of apocytochrome c to the mitochondrial surface, transfer across the outer membrane, covalent addition of protoheme, refolding of the polypeptide chain, and association of holocytochrome c with its functional sites at the inner membrane. the binding step of apocytochrome c to neurospora crassa mitochondria was studied by inhibiting the subsequent transfer steps with the heme anal ...19836308663
complete nucleotide sequence of the escherichia coli gdha gene.the dna sequence of the gdha gene of escherichia coli k12, which encodes the 447 amino acid polypeptide subunit of nadp-specific glutamate dehydrogenase, is presented. the deduced protein sequence is strongly homologous to the corresponding enzyme of the eukaryotic fungus neurospora crassa. the upstream dna sequence includes several overlapping promoter consensus sequences. the downstream dna sequence contains inverted repeats, predicted as forming long stable stem-loop structures in rna, homolo ...19836308576
neurospora tyrosinase: structural, spectroscopic and catalytic properties.tyrosinase is a copper containing monooxygenase catalyzing the formation of melanin pigments and other polyphenolic compounds from various phenols. this review deals with the recent progress on the molecular structure of the enzyme from neurospora crassa and the unique features of the binuclear active site copper complex involved in the activation of molecular oxygen and the binding of substrates. the results of the spectroscopic properties of neurospora tyrosinase will also be discussed in the ...19836308414
cloning of the structural gene for orotidine 5'-phosphate carboxylase of neurospora crassa by expression in escherichia coli.a neurospora gene bank in plasmid prk9 was used to complement pyrimidine auxotrophs in e. coli. two plasmids were obtained that complement a pyrf mutant of e. coli. these plasmids hybridise to neurospora dna and transform a pyr-4 strain of neurospora. the promoter used in expressing the orotidine 5'-monophosphate carboxylase in e. coli is within the neurospora sequence.19836308396
molybdenum cofactor in chlorate-resistant and nitrate reductase-deficient insertion mutants of escherichia coli.we examined molybdenum cofactor activity in chlorate-resistant (chl) and nitrate reductase-deficient (nar) insertion mutants and wild-type strains of escherichia coli k-12. the bacterial molybdenum cofactor was assayed by its ability to restore activity to the cofactor-deficient nitrate reductase found in the nit-1 strain of neurospora crassa. in the wild-type e. coli strains, molybdenum cofactor was synthesized constitutively and found in both cytoplasmic and membrane fractions. cofactor was fo ...19836307982
Displaying items 3201 - 3300 of 5889