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Xylitol production is increased by expression of codon-optimized Neurospora crassa xylose reductase gene in Candida tropicalis.Xylose reductase (XR) is the first enzyme in D: -xylose metabolism, catalyzing the reduction of D: -xylose to xylitol. Formation of XR in the yeast Candida tropicalis is significantly repressed in cells grown on medium that contains glucose as carbon and energy source, because of the repressive effect of glucose. This is one reason why glucose is not a suitable co-substrate for cell growth in industrial xylitol production. XR from the ascomycete Neurospora crassa (NcXR) has high catalytic effici ...201121922311
Structural elements of the mitochondrial preprotein-conducting channel Tom40 dissolved by bioinformatics and mass spectrometry.Most mitochondrial proteins are imported into mitochondria from the cytosolic compartment. Proteins destined for the outer or inner membrane, the inter-membrane space, or the matrix are recognized and translocated by the TOM machinery containing the specialized protein import channel Tom40. The latter is a protein with ß-barrel shape, which is suggested to have evolved from a porin-type protein. To obtain structural insights in the absence of a crystal structure the membrane topology of Tom40 fr ...201121888892
Meiotic silencing by unpaired DNA is expressed more strongly in the early than the late perithecia of crosses involving most wild-isolated Neurospora crassa strains and in self-crosses of N. tetrasperma.Meiotic silencing by unpaired DNA is a presumed RNAi-mediated elimination of the transcripts of any gene that is not properly paired with a homolog in meiosis. Eighty wild-isolated strains of Neurospora crassa were classified into three types based on the apparent strength of meiotic silencing of the bml (ß-tubulin) and mei-3 genes in crosses with the ::Bml(r) and ::mei-3 tester strains. "OR" and "Sad" type wild-isolates, respectively, did or did not silence both the genes, whereas the "Esm" typ ...201122056520
The Neurospora crassa mutant Nc?Egt-1 identifies an ergothioneine biosynthetic gene and demonstrates that ergothioneine enhances conidial survival and protects against peroxide toxicity during conidial germination.Ergothioneine (EGT) is a histidine derivative with sulfur on the imidazole ring and a trimethylated amine; it is postulated to have an antioxidant function. Although EGT apparently is only produced by fungi and some prokaryotes, it is acquired by animals and plants from the environment, and is concentrated in animal tissues in cells with an EGT transporter. Monobromobimane derivatives of EGT allowed conclusive identification of EGT by LC/MS and the quantification of EGT in Colletotrichum gramini ...201122209968
the neurospora crassa os mapk pathway-activated transcription factor asl-1 contributes to circadian rhythms in pathway responsive clock-controlled genes.the os-pathway mitogen-activated protein kinase (mapk) cascade of neurospora crassa is responsible for adaptation to osmotic stress. activation of the mapk, os-2, leads to the transcriptional induction of many genes involved in the osmotic stress response. we previously demonstrated that there is a circadian rhythm in the phosphorylation of os-2 under constant non-stress inducing conditions. additionally, several osmotic stress-induced genes are known to be regulated by the circadian clock. ther ...201222240319
fungal photobiology: a synopsis.fungi respond and adapt to many environmental signals including light. the photobiology of fungi has been extensively investigated, but in recent years the identification of the first fungal photoreceptor, wc-1 in the ascomycete neurospora crassa, and the discovery that similar photoreceptors are required for photoreception in other ascomycete, basidiomycete and zygomycete fungi has allowed the molecular characterization of light reception and the early steps of signal transduction in a number o ...201122679584
self/nonself recognition in tuber melanosporum is not mediated by a heterokaryon incompatibility system.vegetative incompatibility is a widespread phenomenon in filamentous ascomycetes, which limits formation of viable heterokaryons. whether this phenomenon plays a role in maintaining the homokaryotic state of the hyphae during the vegetative growth of tuber spp. gene expression, polymorphism analysis as well as targeted in vitro experiments allowed us to test whether a heterokaryon incompatibility (hi) system operates in tuber melanosporum. hi is controlled by different genetic systems, often inv ...201122289772
the kinetics of changes in the fatty acid composition of neurospora crassa lipids after a temperature increase.the fatty acid composition of the total lipids, phospholipids and neutral lipids of log-phase shaker cultures of the bd (band) strain of neurospora crassa, were measured every 2 h for an 8-h period following a temperature increase from 22 to 40 degrees c. for purposes of comparison, the fatty acid composition was also measured when cultures were grown from inoculation at temperatures between 22 and 40 degrees c. in the phospholipids, the temperature jump produced, over a 4-6 hour span, a linear ...20113159434
purification and characterization of epsilon-n-trimethyllysine l-amino oxidase from neurospora crassa.epsilon-n-trimethyllysine l-amino oxidase from neurospora crassa has been purified to electrophoretic homogeneity. a 1500-fold purification was obtained by centrifugation and successive column chromatography on ion-exchange and gel filtration supports. the enzyme has an estimated molecular weight of 160 000. it transforms epsilon-n-trimethyllysine into alpha-keto, epsilon-n-trimethylhexanoic acid by oxidative deamination. kinetic studies of this new enzyme are reported and its probable physiolog ...2003149561
cytochrome b in neurospora crassa mitochondria. site of translation of the heme protein. 20144273944
developmental control of glucosamine and galactosamine levels during conidation in neurospora crassa.the glucosamine and galactosamine content of mycelia was measured in cultures of neurospora crassa grown on the surface of dialysis membranes. the glucosamine content was relatively constant throughout the different regions of the mycelial mat. the galactosamine content, however, was always lower in the growing-front region of the mycelial mat than in the older regions. at most, only low levels of galactosamine were necessary for the formation of hyphae at the growing front of a mycelial mat. th ...2001125260
investigations on myo-inositol-1-phosphate synthase from the wild type and the inositol-dependent mutant of neurospora crassa.the inositol-dependent mutant of neurospora crassa lacks inositol-1-phosphate synthetase activity. this defect can be revorted by the addition of high-molecular dna isolated from the wild type. to elucidate the biochemical background of inositol dependence, inositol-1-phosphate synthetase was studied. a method has been developed fro the isolation of the enzyme from the wild type strain in 10 mg scale by salt fractionation, gel filtration and ion-exchange chromatography. the specific activity of ...2001150187
isolation and characterization of a mutant of neurospora crassa deficient in general amino acid permease activity.a mutant of neurospora crassa (pm-nbg27) was isolated on the basis of its resistance of p-fluoro-phenylalanine on ammonium-deficient vogel's medium. this mutant was found to be devoid of both conidial and post-conidial (after 180 min of preincubation) transport activity of all amino acids. genetic analysis of pm-nbg27 by crossing it to wild-type (74a) resulted in the predicted segregants exhibiting transport characteristics of pm-n, pm-b, pm-g, pm-nb, pm-ng, pm-bg and parental types. the above o ...2002127619
use of liquid nitrogen and high ionic strength for the isolation of functional polyribosomes from neurospora crassa. 20144271372
properties of two nuclease genes in neurospora crassa.two genes, nuc-1 and nuc-2, of neurospora crassa which were responsible for the nucleic acid digestion, were located on linkage group 1 and 2, respectively. a temperature-sensitive mutant (b1ts-2) was obtained from a nuc-2 mutant. nuclease mutants showed a reduced activity of nuclease n(3) which was found to be a complex consisting of nuclease n(3) (') and inhibitor molecule. nuclease n(3), nuclease n(3) (') and inhibitor were partially purified and estimated to have the approximate molecular we ...20144260181
biosynthesis of glycogen in neurospora crassa. kinetic mechanism of udp-glucose: glycogen 4-alpha-glucosyltransferase.the kinetic mechanism of glycogen synthase [udp-glucose: glycogen 4-alpha-glucosyltransferase, ec 2.4.1.11], glucose-6-p-dependent form, from neurospora crassa has been investigated by initial velocity experiments and studies with inhibitors in the presence of sufficient levels of glucose-6-p. the rate equation was different from those of common two-substrate systems because one of the substrates, glycogen, is also a product. the reaction rates were determined by varying the concentration of one ...2003153901
light-induced absorbance changes in cell-free extracts of neurospora crassa. 2002135267
role of cytochrome c heme lyase in the import of cytochrome c into mitochondria.the import of cytochrome c into neurospora crassa mitochondria was examined at distinct stages in vitro. the precursor protein, apocytochrome c, binds to mitochondria with high affinity and specificity but is not transported completely across the outer membrane in the absence of conversion to holocytochrome c. the bound apocytochrome c is accessible to externally added proteases but at the same time penetrates far enough through the outer membrane to interact with cytochrome c heme lyase. format ...20092848813
the structure and development of septa in neurospora crassa. 20144278339
influence of an aggregated multienzyme system on transient time: kinetic evidence for compartmentation by an aromatic-amino-acid synthesizing complex of neurospora crassa.the aromatic complex of neurospora crassa is an aggregated multienzyme system which catalyzes five consecutive reactions in the central pathway leading to the biosynthesis of the aromatic amino acids. in an attempt to understand the physiological importance of this complex in particular, as well as the importance of cellular organization of enzyme systems in general, we have isolated the complex and have begun to characterize its catalytic properties. optimum conditions for the assay of the over ...2002128001
change of the cytochrome oxidase level during exponential growth in neurospora crassa.in neurospora cells growing in various media, the specific activity of cytochrome oxidase increases very markedly during early exponential growth, reaching a maximum after 4-5 duplication times, then it slowly declines.2003169142
cyclic amp-induced tyrosinase synthesis in neurospora crassa. 20154376002
pyruvate kinase of neurospora crassa: purification and some properties. 20144260764
subunit structure of anthranilate synthetase from neurospora crassa.freshly purified preparations of anthranilate synthetase complex from neurospora crassa appeared to be homogeneous on polyacrylamide disc gels and were composed of two distinct subunits, 94,000 and 70,000 daltons, respectively, as determined by electrophoresis on polyacrylamide gels in the presence of sodium dodecyl sulfate. carboxymethylation of the complex or treatment with guanidine hydrochloride and urea before sodium dodecyl sulfate treatment did not alter the subunit pattern. when the puri ...2001125757
genetic evidence on the organization and action of the qa-1 gene product: a protein regulating the induction of three enzymes in quinate catabolism in neurospora crassa.the first three reactions in the catabolism of qainic acid in neurospora crassa are under the genetic control of the qa gene cluster. this cluster consists of three structural genes encoding three inducible enzymes plus a regulatory gene (qa-1+) whose diffusible product apparently acts in a positive fashion to initiate coordinate synthesis of the three enzymes when an appropriate inducer is present. genetic and biochemical evidence for both complementing and temperature-sensitive qa-1 alleles in ...2002123642
differential deoxyribonucleic acid synthesis during microcycle conidiation in neurospora crassa.in conidia of neurospora crassa germinating at 25 degrees c, dna synthesis measured by incorporation of tritiated adenosine reaches a maximum soon after the outgrowth of the germ tube (6--7 h after inoculation). in conidia heat-treated at 46 degrees c (for 15 h), a maximum of incorporation of the dna precursor occurs already 1 h after inoculation, then the incorporation progressively declines until the end of the heat-shock. when such conidia are shifted to 25 degrees c, a maximum of dna synthes ...2003153737
stimulation of folate metabolism by exogenous glycine in neurospora crassa wild type. 2002124265
processing of precursor rnas from mitochondria of neurospora crassa.neurospora mitochondrial dna is transcribed into long molecules containing the information of several genes. processing leads to formation of functionally active rnas. it has been shown previously that when trna sequences are present in these transcripts excision of mrnas occurs at the acceptor stem of these trna sequences. we have investigated the processing of precursor rnas transcribed from a region of the mitochondrial genome devoid of trna genes. this region comprises the genes encoding sub ...20072958778
isolation and characterization of nuclei from neurospora crassa.a procedure was developed for isolating nuclei from either the conidial or germinated conidial growth phase of neurospora crassa. a frozen conidial suspension was lysed by passage through a french pressure cell, and the nuclei were freed from the broken cells by repeated homogenization in an omni-mixer. pure nuclei were obtained from the crude nuclear fraction by density banding in a ludox gradient. the final nuclear yield was 20 to 30%. the nuclei had a deoxyribonucleic acid (dna):ribonucleic a ...1995162536
6-phosphogluconate dehydrogenase from neurospora crassa. 2002124005
enzymes of neurospora crassa which attack uv-irradiated dna.two excision-deficient mutants of neurospora crassa contain normal levels of two enzymes, a single-strand-specific exonuclease and a single-strand specific endonuclease, which attack uv-irradiated dna. mutants of n. crassa have been obtained in which the activity of the latter enzyme as well as an activity with native dna are simultaneously affected. these activities are also apparently low in excision-proficient uvs3 strain of n. crassa which has many of the characteristics of the reca mutants ...2002127578
siroheme: a prosthetic group of the neurospora crassa assimilatory nitrite reductase.the neurospora crassa assimilatory nitrite reductase (ec 1.6.6.4) catalyzes the nadph-dependent reduction of nitrite to ammonia, a 6-electron transfer reaction. highly purified preparations of this enzyme exhibit absorption spectra which suggest the presence of a heme component (wavelength maxima for oxidized senzyme: 390 and 578 nm). there is a close correspondence between nitrite reductase activity and absorbance at 400 nm when partially purified nitrite reductase preparations are subjected to ...2002126995
studies on copper toxicity in neurospora crassa. 2003161548
sterol content and enzyme defects of nystatin-resistant mutants of neurospora crassa.non-saponifiable cell extracts of wild type and sterol mutants of n. crassa were analysed by means of gas-liquid chromatography. the wild-type contained ergosterol and episertol in a 10:1 ratio. none of the mutants was able to synthesize ergosterol. three of the mutants carry single recessive gene mutations cauisng blocks in the terminal steps of ergosterol biosynthesis: erg-1 has an inactive delta 8 leads to delta 7 isomerase erg-2 has an inactive 24(28) hydrogenase, and erg-4 has an inactive c ...2003154056
purification of cytochrome b from neurospora crassa and other sources. 2003152379
quelling: transient inactivation of gene expression in neurospora crassa by transformation with homologous sequences.up to 36% of neurospora crassa transformants showing an albino phenotype were recovered by transforming a wild-type strain with different portions of the carotenogenic albino-3 (al-3) and albino-1 (al-1) genes. the presence of the exogenous sequences (which were randomly integrated in ectopic locations) provoked a severe impairment in the expression of the endogenous al-1 or al-3 genes. this phenomenon, which we have termed 'quelling', was found to be spontaneously and progressively reversible, ...20061484489
glutamine assimilation pathways in neurospora crassa growing on glutamine as sole nitrogen and carbon source.neurospora crassa wild-type is almost unable to grow on glutamine as sole nitrogen and carbon source but a gdh-; gs +/- double mutant strain, lacking nadp-dependent glutamate dehydrogenase and partially lacking glutamine synthetase did grow. under these conditions, the double mutant had a higher chemical energy content than the wild-type. enzyme assays and labelling experiments with glutamine indicated that in the double mutant glutamine was degraded to ammonium and to carbon skeletons by glutam ...20082576659
chorismate synthase: a bifunctional enzyme in neurospora crassa. 20102955201
activation of membrane-bound adenylate cyclase by glucagon in neurospora crassa.membrane-bound adenylate cyclase in neurospora crassa is activated by glucagon. half-maximal effect is observed at hormone concentrations of about 10 nm. after solubilization of the enzyme with lubrol-px, the glucagon effect is lost. incubation of neurospora cells with glucagon leads to a decrease in the activity of glycogen synthetase (ec 2.4.1.11) and to an increase in the activity of glycogen phosphorylase (ec 2.4.1.1) and in the rate of glycogenolysis.20144263508
[effect of some orotaldehyde derivatives as orotic acid antagonists in neurospora crassa]. 20144391358
chemically induced reversion and suppression of methionine-i alleles of neurospora crassa. 20154357302
the role of carbohydrate in the glycoenzyme invertase of neurospora crassa.data obtained concerning the carbohydrate moieties of the glycoenzyme invertase (ec 3.2.1.26, beta-d-fructofuranoside fructohydrolase) from neurospora crassa were consistent with a linkage of some carbohydrate chains by o-glycosidic bonds to serine and threonine residues; the possibility of n-glycosylamine linkage of some of the carbohydrate to the amide group of asparagine is also indicated. the invertase was remarkably stable on storage at low temperatures. oxidation of the carbohydrate residu ...1992195681
an altered invertase in the cot-2 mutant of neurospora crassa.because the cot-2 and inv loci of neurospora crassa are closely linked, the invertase from the morphological mutant, cot-2, was examined. the cot-2 strains produce an invertase with altered heat sensitivity, km, and ratio of heavy to light forms. the cellular localization of cot-2 invertase is different from that of the wild type. there were no observable changes in the energy of activation or the ph optimum of cot-2 invertase, and some of the differences detected were not apparent under culture ...1986239095
genetic and metabolic regulation of purine base transport in neurospora crassa.neurospora crassa can utilize various purine bases such as xanthine or uric acid and their catabolic products as a nitrogen source. the early purine catabolic enzymes in this organism are regulated by induction and by ammonium repression. studies were undertaken to investigate purine base transport and its regulation in neurospora. the results of competition experiments with uric acid and xanthine transport strongly suggest that uric acid and xanthine share a common transport system. it was also ...2002139563
studies on the poky mutant of eurospora crassa. fingerprint analysis of mitochondrial ribosomal rna.base sequence and methylation of mitochondrial ribosomal rnas from wild type and poky strains of neurospora crassa were compared to determine whether a mutational lesion exists in poky 19 s rna. at the outset, new procedures were developed for the isolation of intact nucleic acids from neurospora mitochondria based on the substitution of ca2+ for mg2+ in the isolation media to inhibit mitochondrial nuclease activity. using these procedures, intact and highly purified 32p-labeled ribosomal rnas w ...1997178661
[proteins from neurospora crassa. 2. immunoelectrophoretically detectable proteins and their relationship to growth time]. 20164973223
organization and control in the arginine biosynthetic pathway of neurospora.eight enzymes involved in the conversion of acetylglutamate to arginine in neurospora crassa were studied. the data indicate that of three enzymes early in the sequence, only the first, acetylglutamate kinase, is a nonorganellar enzyme. the next two, n-acetyl-gamma-glutamyl-phosphate reductase and acetylornithine aminotransferase, are in the mitochondrion, which was previously shown to contain the subsequent enzymes: acetylornithine-glutamate acetyltransferase, ornithine carbamyltransferase, and ...2003166979
levels of the ribonucleoside triphosphates and rate of rna synthesis in neurospora crassa.the levels of the four ribonucleoside triphosphate (atp, gtp, utp and ctp) have been determined in neurospora crassa in three conditions of exponential growth (on glucose, acetate and glycerol) as well as in the course of a shift-up and a shift-down transition of growth between two of them. although in some cases the pools appear proportional to the rate of synthesis of ribosomal rna, this seems not to be strictly dependent on the level of the nucleotides.2003141945
nuclear suppressors of the (poky) cytoplasmic mutant in neurospora crassa. ii. mitochondrial cytochrome systems.the mitochondrial cytochrome aa3 and b deficiencies of the [poky] cytoplasmic mutant of neurospora crassa are partially suppressed by mutant alleles of any one of six nuclear genes, namely sup-1, sup-3, sup-4, sup-5, sup-10 and sup-14. the suppressor-induced increases in the concentration of both cytochromes are detected in the mitochondria from exponentially growing [poky] cultures, and, thus, are clearly distinguishable from the age-dependent changes in the cytochrome system that occur in cult ...2003140757
kinetic model of the effects of electrogenic enzymes on the membrane potential.electrogenic enzymes contribute to the electrical field existing across biological membranes by using a source of free energy to generate an ionic current. the model introduced here permits one to evaluate this contribution. since the model incorporates the electrogenic enzyme in the form of a sequential kinetic diagram, it permits one to study the kinetic effects of the concentration of the enzyme, the substrates and the different ligands on the membrane potential. ionic electrodiffusion is exp ...20082593671
molecular cloning of nit-2, a regulatory gene required for nitrogen metabolite repression in neurospora crassa.we used an efficient sib-selection procedure to isolate a cosmid clone that complemented a mutated nit-2 gene of neurospora crassa. restriction fragment length polymorphism mapping indicated that the cosmid dna insert was derived from linkage group il, between 5s rdna locus 12 and mt, the region of the n. crassa genome that contains nit-2. we conclude that the cosmid carries the nit-2 gene.20102879771
nitrogen regulation of glutamine synthetase in neurospora crassa.a higher activity of glutamine synthetase (ec 6.3.1.2) was found in neurospora crassa when nh4+ was limiting as nitrogen source than when glutamate was limiting. when glutamate, glutamine or nh4+ were in excess, a lower activity was found. immunological titration and sucrose gradient sedimentation of the enzyme established that under all these conditions enzyme activity corresponded to enzyme concentration and that the octamer was the predominant oligomeric form. when n. crassa was shifted from ...199827575
regulation of 2-phosphoenolpyruvate carboxykinase and isocitrate lyase syntheses in neurospora crassa. 2002123004
[isolation and properties of plasma membranes of neurospora crassa mycelium]. 20144264117
genetic and enzymatic analysis of a glycerol kinase deficient mutant in neurospora crassa.genetic analysis showed that the glycerol non-utilizing isolate gly-u(234) of neurospora crassa is derived by mutation in a nuclear gene situated in the right arm of linkage group i, about 2.2 cross-over units distal to ad-9 and 11 units proximal to nit-1. enzymatic testings using a radiochemical method indicate that the mutant is deficient for the enzyme glycerol kinase. the radiochemical testings further indicate that the mutation has inactivated an inducible glycerol kinase, while a low resid ...1996177854
glycogen synthesis in the fungus neurospora crassa.an enzymic activity, obtained from neurospora crassa, catalyzing the incorporation of [14c]glucose from adp-[14c]glucose into a glucan of the glycogen type, is described. the properties of the adpglucose : glycogen glucosyltransferase as compared with those of the already known udp glucose : glycogen glucosyltransferase were studied. the radioactive products obtained with udp-14c]glucose or adp-[14c]glucose released all the radioactivity as maltose after alpha or beta amylase treatment. glucose ...2002148915
chitinase from neurospora crassa. 20102976112
recombination in the am gene of neurospora crassa--a new model for conversion polarity and an explanation for a marker effect.it is argued that polarised intragenic recombination is not necessarily due to hybrid dna extending into the gene for variable distances from one side; it can as well be explained by hybrid dna usually covering the whole gene, the two complementary dna strands of the gene having unequal chances of undergoing the interchromatid transfer involved in hybrid dna formation, and excision from base-pair mismatches proceeding predominantly in one chemical direction (perhaps 5' to 3'). this alternative m ...2002130365
reproducibility of vitamin assays with mutants of neurospora crassa maintained by freeze-drying.three mutant strains (atcc 9277, atcc 9278, atcc 9683) of neurospora crassa requiring choline, inositol, and p-aminobenzoic acid respectively for normal growth were deposited at the atcc by g.w. beadle 30 years ago and were preserved at various time intervals by freeze-drying. each preservation batch yielded cultures that, when used for biological assays, exhibited the same biochemical properties as they originally possessed. the freeze-drying technique is shown to be applicable to preserving bi ...2002134828
biochemical genetic studies of cycloheximide resistance in neurospora crassa.genetic analysis of a number of cycloheximide-resistant mutants of neurospora crassa has shown that resistance is controlled by several genes. two of these appear to be located on linkage group v. resistance to the antibiotic is dominant in wild-type-mutant heterokaryons. two types of cycloheximide-resistant mutants were isolated: one type exhibited colonial morphology only when grown in the presence of cycloheximide and the other type maintained normal morphology even at high concentrations of ...2002126683
purification of the arom multienzyme aggregate from euglena gracilis.the arom multienzyme complex that catalyzes steps two through six in the prechorismate polyaromatic amino acid biosynthetic pathway has been purified up to 2000-fold from euglena gracilis. the native arom aggregate has a molecular weight of approx. 249 000 based on a sedimentation coefficient of 9.5 and stokes radius of 60 angstrom. a comparison between the arom aggregates of neurospora crassa and euglena gracilis and the possible phylogenetic relationships between the organisms are discussed.2003156559
the mauriceville plasmid of neurospora crassa: characterization of a novel reverse transcriptase that begins cdna synthesis at the 3' end of template rna.the mauriceville and varkud plasmids are retroid elements that propagate in the mitochondria of some neurospora spp. strains. previous studies of endogenous reactions in ribonucleoprotein particle preparations suggested that the plasmids use a novel mechanism of reverse transcription that involves synthesis of a full-length minus-strand dna beginning at the 3' end of the plasmid transcript, which has a 3' trna-like structure (m. t. r. kuiper and a. m. lambowitz, cell 55:693-704, 1988). in this s ...20051383691
preparation of mitochondrial membrane proteins from neurospora crassa: prevention of lipid autoxidation damage by an antioxidant. 20144266161
genetic alterations at the molecular level in x-ray induced ad-3b mutants of neurospora crassa. 20144265447
effect of n2 on the mutagenic and lethal activities of icr-170 in neurospora crassa.the nature of the n2 effect for icr-170, i.e., the greater mutagenic and lethal activities of this agent in the presence of n2 than o2, has been studied at the ad-3 region of neurospora crassa. the characteristics of the n2 effect for icr-170 were that (1) the n2 effect with icr-170 was displayed in conidia when n2 was administered during, but not before or after, icr-170 treatment, (2) the highly increased mutagenic and lethal activities of icr-170 in the presence of n2 were due to an anoxic co ...200190338
induced transfer of higher plant chloroplasts into fungal protoplasts.chloroplasts isolated from spinach leaves have been transferred in large numbers into protoplasts of neurospora crassa with the help of polyethylene glycol. the chloroplasts show high photosynthetic activity--at least until the time of uptake--and the protoplasts continue to show active cytoplasmic streaming after chloroplast uptake.2002127380
genetic alterations of ribonuclease-sensitive glycoprotein subunits of amino acid transport systems in neurospora crassa conidia. 2002123728
catalase of neurospora crassa. 2. electron paramagnetic resonance and chemical properties of the prosthetic group. 1969223625
biogenesis of cytochrome c in neurospora crassa. synthesis of apocytochrome c, transfer to mitochondria and conversion to holocytochrome c.1. precipitating antibodies specific for apocytochrome c and holocytochrome c, respectively, were employed to study synthesis and intracellular transport of cytochrome c in neurospora in vitro. 2. apocytochrome c as well as holocytochrome c were found to be synthesized in a cell-free homogenate. a precursor product relationship between the two components is suggested by kinetic experiments. 3. apocytochrome c synthesized in vitro was found in the post-ribosomal fraction and not in the mitochondr ...1984215405
complex iii from mitochondria on neurospora crassa: purification, characterization, and resolution. 1987213696
the state of copper in neurospora laccase.1. neurospora crassa laccase has been prepared from the growth medium and studied by optical absorption, circular dichroism and electron paramagnetic resonance (epr) spectroscopy. the molecular weight, the copper content and the amino acid composition have also been determined. 2. the molecular weight as determined by gel filtration in 6 m guanidine hydrochloride and by sodium dodecyl sulfate gel electrophoresis is found to be 64 000. the enzyme contains 3.8 copper ions per 64 000. 3. the visibl ...1992207349
transport of cytoplasmically synthesized proteins into the mitochondria in a cell free system from neurospora crassa.synthesis and transport of mitochondrial proteins were followed in a cell-free homogenate of neurospora crassa in which mitochondrial translation was inhibited. proteins synthesized on cytoplasmic ribosomes are transferred into the mitochondrial fraction. the relative amounts of proteins which are transferred in vitro are comparable to those transferred in whole cells. cycloheximide and puromycin inhibit the synthesis of mitochondrial proteins but not their transfer into mitochondria. the transf ...1996145943
enzymes of deoxythymidine triphosphate biosynthesis in neurospora crassa mitochondria.intact mitochondria of neurospora crassa incorporate deoxythymidine 5'-monophosphate (dtmp) into deoxyribonucleic acid but not the label from (methyl-3h) deoxythymidine. mitochondrial homogenates contain deoxythymidylate kinase (ec 2.7.4.9), deoxycytidylate aminohydrolase (dcmp deaminase) (ec 3.5.4.12), and thymidylate synthetase (ec 2.1.1b), but not thymidine kinase (ec 2.7.1.21) activity. dtmp kinase is loosely bound to the mitochondrial membrane and is solubilized by 0.4 m kcl in mitochondria ...1996163227
oxidation processes and ubiquinone localization in the branched respiratory system of mi-1 mutant of neurospora crassa.1. stimulation of succinate oxidation in mi-1 mitochondria by mg2+ and pi is abolished on uncoupling, which points to the energy-linked activation of succinate oxidation. 2. mitochondria exhibited respiratory control with succinate and nadh when the cyanide-insensitive oxidation was inhibited by salicylhydroxamic acid (sham). sham lowered the oxidation rate with nadh and succinate to the same level, though the nadh oxidation rate was 2.5 times as high as with succinate. 3. despite the high stimu ...1997168706
current-voltage relationships for the plasma membrane and its principal electrogenic pump in neurospora crassa: i. steady-state conditions.the nonlinear membrane current-voltage relationship (i-v curve) for intact hyphae of neurospora crassa has been determined by means of a 3-electrode voltage-clamp technique, plus "quasi-linear" cable theory. under normal conditions of growth and respiration, the membrane i-v curve is best described as a parabolic segment convex in the direction of depolarizing current. at the average resting potential of - 174 mv, the membrane conductance is approximately 190 micronhos/cm2; conductance increase ...199825343
regulation of the neurospora crassa assimilatory nitrate reductase.reduced nicotinamide adenine dinucleotide phosphate (nadph)-nitrate reductase from neurospora crassa was purified and found to be stimulated by certain amino acids, citrate, and ethylenediaminetetraacetic acid (edta). stimulation by citrate and the amino acids was dependent upon the prior removal of edta from the enzyme preparations, since low quantities of edta resulted in maximal stimulation. removal of edta from enzyme preparations by dialysis against chelex-containing buffer resulted in a lo ...199819423
neurospora crassa glutamine synthetase. role of enzyme synthesis and degradation on the regulation of enzyme concentration during exponential growth.the specific activity of neurospora crassa glutamine synthetase varies according to the nitrogen source in which the organism is grown. in a poor nitrogen source such as glutamate, the specific activity of the enzyme is higher than that found in good nitrogen sources such as ammonium or glutamine. these differences in specific enzyme activity correspond to differences in enzyme concentration. the relative rates of glutamine synthetase synthesis and degradation were measured in exponential cultur ...199921883
affinity chromatography of the neurospora nadp-specific glutamate dehydrogenase, its mutational variants and hybrid hexamers.the synthesis of an affinity adsorbent, 8-(6-aminohexyl)aminoadenosine 2'-phosphate-sepharose 4b, is described. the assembly of the 2'-amp ligand and the hexanediamide spacer arm was synthesized in free solution before its attachment to the sepharose matrix. this adsorbent retarded the hexameric nadp-specific glutamate dehydrogenase of neurospora crassa, showing a capacity for this enzyme similar to that of comparable coenzyme-analogue adsorbents for other dehydrogenases. the enzyme was eluted e ...199922328
purification and characterization of 3-dehydroshikimate dehydratase, an enzyme in the inducible quinic acid catabolic pathway of neurospora crassa.3-dehydroshikimate dehydratase catalyzes the third reaction in the inducible quinic acid catabolic pathway of neurospora crassa and is encoded in the qa-4 gene of the qa gene cluster. as part of continuing genetic and biochemical studies concerning the organization and regulation of this gene cluster, 3-dehydroshikimate dehydratase has been purified and characterized biochemically. the enzyme was purified 1650-fold using the following techniques: 1) (nh4)2so4 fractionation; 2) ion exchange chrom ...2000149131
does cycloheximide-induced loss of phosphate uptake activity in neurospora crassa reflect rapid turnover?addition of cycloheximide to neurospora crassa germlings growing in liquid medium caused an exponential loss of phosphate uptake activity (half-life, ca. 2 h). no loss of activity resulted when germlings were resuspended, at the time of cycloheximide addition, in medium of a substantially lower phosphate concentration. it is concluded that the phosphate uptake systems are not subject to rapid turnover.2000149111
an unstable allele of the am locus of neurospora crassa.the mutant strain am126 was isolated, using the direct selection procedure, after nitrous acid mutagenesis. it produced neither measurable nadp-dependent glutamate dehydrogenase (gdh) nor immunologically cross-reacting material. that the am126 strain produced some form of gdh product was shown by the fact that it complemented several other am mutant strains. the gdh formed by complementation between am126 and each of two other am mutants was relatively thermolabile, but could not be distinguishe ...200094569
isolation and characterization of a mitochondrial d-amino acid oxidase from neurospora crassa.d-amino acid oxidase (ec 1.4.3.3) activity in homogenates of neurospora crassa strain sy7a was found to sediment with the mitochondrial fraction. digitonin fractionation studies on purified mitochondria have indicated a matrix localization of the enzyme. additionally, a peroxidase (ec 1.11.1.7) activity, which may remove hydrogen peroxide formed as a product of d-amino acid oxidation, was also found in the mitochondrial matrix. partial purification (20- to 30-fold) of the mitochondrial d-amino a ...200013919
cellulase of neurospora crassa.mycelia and ungerminated conidia of neurospora crassa were found to secrete extracellular endocellulase (ec 3.2.1.4). a simple induction system of potassium phosphate buffer (ph 6.0) plus inducer relied on the internal metabolic reserves of conicia or mycelia to provide energy and substrates for protein synthesis. buffer concentration for optimum enzyme production was 100 mm, but at higher buffer concentrations enzyme production was inhibited. cellobiose was clearly the best inducer, with an opt ...200015975
letter: methylation of mitochondrial rna species in the wild-type and poky strains of neurospora crassa. 2001125795
enzymatic and non-enzymatic reduction of nitrite by extracts of neurospora crassa.two activites causing nitrite disappearance are found in extracts of neurospora; one, inducible by nitrate or nitrite and present only in nitrite-utilizing strains, catalyze the stoichiometric reduction of nitrite to ammonia; the other, present in all strains under all conditions, causes the disappearance of nitrite to something other than ammonia. the latter activity has a molecular weight of about 600 and may contain an oligopeptide, a metal, and an sh group(s). it has no known physiological f ...2001125270
microbial transformation of artificial estrogens of the allenolic group.when 2,2-dimethyl 3-(2'-naphthyl 6'-hydroxy) pentanoic acid, an artificial estrogen of the allenolic acid group, was added to an exponential-phase growth culture of neurospora crassa (in horowitz medium), it was transformed into its hydroxylated derivative, 2,2-dimethyl 3-(2'-naphthyl 4',6'-dihydroxy)pentaoic acid. to study this transformation, radioactive 2-methyl-[2-14-c=a1methyl 3-(2'-naphthyl 6'-hydroxy) pentanoic acid has been prepared. the rate of metabolism of allenolic acids varies in th ...2001125267
scanning electron microscopy of surface and internal features of developing perithecia of neurospora crassa.stages in the development of perithecia of neurospora crassa, designated by the time elapsed after crossing, were investigated with the scanning electron microscope, from protoperithecia through perithecia. the usual examination of external features of whole specimens with this instrument was augmented by a freeze-fracture technique which allowed the viewing of development internally as well. rapid increases in perithecial size soon after crossing were followed by the appearance, in section, of ...2001125266
death resulting from unbalanced growth in a temperature-sensitive mutant of neurospora crassa.a temperature-sensitive mutant of neurospora crassa was found to undergo rapid death on minimal medium at 35 degrees c. the loss of viability in this mutant was prevented by various factors which retard growth, including deprivation of carbon sources or interruption of protein synthesis. synthesis of nucleic acids and protein in this mutant was normal at the early stages of germination and then depressed at 35 degrees c. the active transport of glucose and the respiration rate in this mutant wer ...2001125567
characterization of the glucose transport systems in neurospora crassa sl.neurospora crassa sl, a mutant that lacks a rigid cell wall, exhibits transport systems for glucose similar to those of wild-type strain 1a. when the orgnism is grown in a medium containing 50 mm glucose as the carbon source, glucose is transported primarily by a glucose-facilitated diffusion system (glui). when it is grown in a medium with little or no glucose present, a glucose active transport system (glu ii) is expressed. both of these systems are similar kinetically to those in the wild typ ...2001125261
[isolation and properties of tripolyphosphatase from neurospora crassa].homogenous preparation of tripolyphosphatase from neurospora crassa is obtained. the enzyme is found to consist of two equal subunits with molecular weight of 40 000 and to have ph optimum 7.0 and temperature optimum 50 degrees c. bivalent metal ions are required for its catalytical activity, the hest activators being co2+, mg2+ and mn2+. strict specificity of the enzyme to tripolyphosphate is demonstrated, km being 5.9-10(-4) m. the enzyme hydrolyses tripolyphosphate to equimolar mixture of ort ...200114720
amino acid sequence of tyrosinase from neurospora crassa.the amino-acid sequence of tyrosinase from neurospora crassa (monophenol,dihydroxyphenylalanine:oxygen oxidoreductase, ec 1.14.18.1) is reported. this copper-containing oxidase consists of a single polypeptide chain of 407 amino acids. the primary structure was determined by automated and manual sequence analysis on fragments produced by cleavage with cyanogen bromide and on peptides obtained by digestion with trypsin, pepsin, thermolysin, or chymotrypsin. the amino terminus of the protein is ac ...2002151279
adenylosuccinate amp-lyase (neurospora crassa). 2002151182
regulation of phosphate metabolism in neurospora crassa: identification of the structural gene for repressible acid phosphatase.a mutant of neurospora crassa with an altered repressible acid phosphatase has been isolated. the enzyme is much more thermolabile than that of wild type, and has an increased michaelis constant. tests of allelic interactions (in partial diploids) and in vitro mixing experiments were consistent with the mutation being in the structural gene for the enzyme. this gene, pho-3, was found to be located in the right arm of linkage group iv (lgiv). thus, pho-3 and the structural gene for repressible al ...2002137163
re-investigation of the effects of l-glutamine and l-asparagine on the neurospora crassa nadp-specific glutamate dehydrogenase.l-glutamine, when purified free of traces of nh4+ present in solution, does not act as an alternative substrate to nh4+ for the nadp-specific glutamate dehydrogenase of neurospora. l-glutamine interferes with detection of small quantities of nh4+ by nessler's reagent. l-asparagine is not an alternative substrate to nh4+ for this enzyme.2002137720
randomness tests on the sequence of ascal segregation classes in neurospora crassa.various statistical tests for randomness were made on the order of ascal classes in groups of asci from wild-type x asco crosses. there was no significant nonrandom clustering of asci of the same segregation class, nor a regular twinning of similar asci. any apparent observed clustering of similar ascal classes is probably an artefact or due to chance. 2 x n x2 tests showed that frequencies of individual ascus classes from different perithecia were generally homogeneous, as were second division ...2002137884
phosphocellulose, an affinity chromatographic system for chorismate synthase and the aromatic complex of neurospora crassa. 2002128358
determination of total choline in biological materials.a microbiological eight-point parallel line assay for the determination of choline has been developed, using neurospora crassa cholineless-1 as test organism. in the common procedure the mold is grown at 25 degrees c in 25 ml basal medium at ph 5.9-6.0. growth studies showed, however, that a better log dose-response curve, with respect to the linear part of the curve, was obtained when the organism was grown at 30 degrees c, in 20 ml experimental volume and at ph 5.5. the proprosed eight-point a ...2002129440
gene order in the qa gene cluster of neurospora crassa.four different types of crosses have been used to establish the order of the four genes in the qa gene cluster of neurospora crassa, which encode the following proteins involved in the inducible catabolism of quinic acid: a regulatory (activator) protein (qa-1), catabolic dehydroquinase (qa-2), quinate dehydrogenase (qa-3), and dehydroshikimate dehydrase (qa-4). the four crosses involved (1) the ordering of the four qa genes relative to the closely-linked me-7 locus; (2) the ordering of the thre ...2002134253
correlation of enzymatic activity and thermal resistance with hydration state in ungerminated neurospora conidia.ungerminated neurospora crassa conidia were incubated at 0, 50, and 100% relative humidity, giving rise to conidia in dry, quasi-dry, and wet hydration states, respectively. metabolic activity was detected by monitoring levels of reduced glutathione (gsh), oxidized glutathione (gssg), and the soluble-amino acid pools as a function of incubation time. wet conidia (approximately 65% water content) exhibited significant metabolic activity as evidenced by: (i) reduction of gssg to gsh, (ii) degradat ...2002151096
some required events in conidial germination of neurospora crassa. 2002136375
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