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uptake, intracellular binding, and excretion of polyamines during growth of neurospora crassa.in neurospora crassa mycelia, the amounts of the main polyamines, putrescine and spermidine, are approximately 0.8 and 18 nmol/mg, dry weight. we wished to know what determines these pool sizes. in the growth medium, externally added polyamines enter cells largely by a nonsaturable, diffusional system. in a mutant unable to polyamines, internal and external spermidine appear to equilibrate across the cell membrane during growth. however, this was true only after an intracellular "sink," with a c ...19892524999
isolation and characterization of cadmium-resistant mutants of neurospora crassa.this study identified and characterized four cadmium-resistant mutants of neurospora crassa. one of these mutants maps to linkage group ii and the other three map to linkage group vii, whereas a naturally occurring resistant trait in a strain from japan resides at a distinct but unmapped locus. transport of cadmium into neurospora cells occurs by more than a single uptake system and involves both energy-dependent and -independent components. the resistant mutants transport cadmium in the same ma ...19892525066
photoaffinity labelling of mitochondrial nadh: ubiquinone reductase with pethidine analogues.1. chemically reactive derivatives of pethidine analogues--novel potent inhibitors of the mitochondrial nadh: ubiquinone reductase (complex i)--were synthesized. 2. dose-response curves of these components revealed that the photoactivatable aryl azido derivative has retained most of the inhibitory activity displayed by the parent substance. after introduction of a radioactive iodine isotope into the molecule, it was used as a probe for the localization of the inhibitor binding polypeptides withi ...19892525381
transformation of neurospora crassa by an integrative transforming plasmid is not enhanced by ribosomal dna sequences.two integrative transforming plasmids of neurospora crassa that differed only by the presence of almost all of a ribosomal dna repeat unit on one plasmid were constructed. the plasmids were used to test the target concentration hypothesis which states that the transformation frequency is proportional to the number of genomic copies of a homologous sequence located on the transforming plasmid. since there are approx. 200 copies of the rdna sequences in the genome, the target concentration hypothe ...19892525404
dna sequence, organization and regulation of the qa gene cluster of neurospora crassa.in neurospora, five structural and two regulatory genes mediate the initial events in quinate/shikimate metabolism as a carbon source. these genes are clustered in an 18 x 10(3) base-pair region as a contiguous array. the qa genes are induced by quinic acid and are coordinately controlled at the transcriptional level by the positive and negative regulators, qa-1f and qa-1s, respectively. the dna sequence of the entire qa gene cluster has been determined and transcripts for each gene have been ma ...19892525625
effects of heat shock on the induction of mutations by chemical mutagens in neurospora crassa.preheating of neurospora conidia increased their susceptibility to mutation induction by chemical mutagens. optimal conditions of heat shock for enhanced mutagenesis were determined in 2.5 x 10(7) conidia/ml 0.067 m kh2po4-na2hpo4 (ph 7.0) buffer to be treatment at 43 degrees c for 60 min. when protein synthesis during heat stock was eliminated by cycloheximide or by use of the temperature-sensitive mutation psi-1, induction of thermotolerance was inhibited while induction of the enhanced state ...19892525670
an optimized procedure for sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of hydrophobic peptides from an integral membrane protein.a procedure for successful analysis of the hydrophobic tryptic peptides of the neurospora crassa plasma membrane h+-atpase by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) is described. the features of this procedure that are essential for the best results include (i) treatment of the hydrophobic peptide samples with neat trifluoroacetic acid, (ii) dissolution and disaggregation of the hydrophobic peptide samples with sds at 0 degrees c, (iii) sds-page of the hydrophobic p ...19892525882
the response time of transcription and translation of the leu-2 gene of neurospora to its inducer, alpha-isopropylmalate, approaches the permissible minimum.the rate of transcription and translation of the leu-2 gene of neurospora crassa was measured after induction by alpha-isopropylmalate. little message of enzyme was found before inducer addition but transcription in the lower eukaryote was found well underway within five minutes after inducer addition, followed in a minute or two by the appearance of functional enzyme. the timing was close to the limit set by rna synthesis and ribosome procession. as a consequence, it seems unlikely that travers ...19892525903
proton nmr studies of a metallothionein from neurospora crassa: sequence-specific assignments by noe measurements in the rotating frame.sequential 1h nmr assignments of a metallothionein from neurospora crassa have been accomplished by the combined use of cosy, 2qf-cosy, hohaha, and rotating-frame noe experiments. all potentially observable resonances were assigned except for the epsilon-nh3 group of the c-terminal lysine. 1h noes, when observed in the laboratory frame and at 500-mhz spectrometer frequency, were negligible in this protein due to the inherent rotational correlation time of the molecule. this difficulty was circum ...19892525920
inducible responses to dna damaging or stress inducing agents in neurospora crassa.two-dimensional polyacrylamide gel electrophoresis has been used to analyze proteins from wild type and mutagen sensitive mutants of neurospora crassa under constitutive conditions and after treatment with mutagens and other stress inducing agents. several proteins have been detected that are either induced or show changes in electrophoretic mobility in response to uv irradiation, 4-nqo, x-ray, paraquat and heat shock. ten proteins were found to respond to more than one of the stress inducing ag ...20082525961
duplication of the trna(mmet) and trna(cys) genes and of fragments of a gene encoding a subunit of the nadh dehydrogenase complex in neurospora grassa mitochondrial dna.neurospora crassa mitochondrial dna (mtdna) contains duplications of the trna(mmet) gene upstream of a gene (nd2) encoding a subunit of the nadh dehydrogenase complex and of the trna(cys) gene which is found downstream of the apocytochrome b gene. both duplicated genes are located upstream of the small rrna gene. the duplications are extended to flanking sequences. in the case of the trna(mmet) duplication, two fragments of the nd2 gene are also duplicated. these two fragments, which are not con ...19892525962
two kinds of "recombination nodules" in neurospora crassa.two morphological types of recombination nodules, termed early and late, are recognized in neurospora crassa. eighty nuclei at different substages were used to determine numbers of nodules per nucleus, distribution of nodules along the nucleolus-organizing chromosome, and distribution of nodules among the two largest chromosomes. early nodules appear at the synaptonemal complex at early zygotene and increase in number during zygotene until a dramatic reduction occurs at zygotene-pachytene transi ...19892526043
involvement of tyrosyl-trna synthetase in splicing of group i introns in neurospora crassa mitochondria: biochemical and immunochemical analyses of splicing activity.we reported previously that mitochondrial tyrosyl-trna synthetase, which is encoded by the nuclear gene cyt-18 in neurospora crassa, functions in splicing several group i introns in n. crassa mitochondria (r. a. akins and a. m. lambowitz, cell 50:331-345, 1987). two mutants in the cyt-18 gene (cyt-18-1 and cyt-18-2) are defective in both mitochondrial protein synthesis and splicing, and an activity that splices the mitochondrial large rrna intron copurifies with a component of mitochondrial tyro ...20082526294
effect of the uvs-2 allele of neurospora crassa on the mutagenic potency of two n-hydroxylaminopurines and 2-aminopurine in the ad-3 forward-mutation test.the mutagenic potencies of 3 purine analogs were determined in the ad-3 forward-mutation test in growing cultures of heterokaryon 59 (h-59), a nucleotide excision repair-deficient (uvs-2/uvs-2) 2-component heterokaryon of neurospora crassa. two n-hydroxylaminopurines, 2-amino-6-n-hydroxylaminopurine (aha) and 6-n-hydroxylaminopurine (hap), were potent and strong mutagens, respectively, whereas 2-aminopurine (ap) was a moderate mutagen. dose-response curves showed that aha and hap were about equa ...19892526296
deoxyribonucleoside triphosphate pools in mutagen sensitive mutants of neurospora crassa.deoxyribonucleoside triphosphate (dntp) levels were measured in wild type neurospora and nine mutagen-sensitive mutants, at nine different genes. eight of these mutants are sensitive to hydroxyurea and histidine and show chromosomal instability, a phenotype which could result from altered levels of dntps. two patterns were seen. five of the mutants had altered ratios of dntps, with relatively high levels of datp and dgtp and low levels of dctp, but changes in the dttp/dctp ratio did not correlat ...19892527032
inositol trisphosphate induces calcium release from neurospora crassa vacuoles.inositol 1,4,5-trisphosphate is known to release calcium ions from intracellular stores thought to be parts of endoplasmic reticulum in animal cells. in neurospora crassa, however, inositol 1,4,5-trisphosphate acts on vacuoles stimulating a calcium efflux with a km of 5.28 microm. the calcium release is inhibited effectively by dantrolene. these results were obtained by applying two independent methods, measuring calcium binding to fura-2 and loading vacuoles with 45ca.19892527035
premeiotic change of nucleolus organizer size in neurospora.we have investigated the heritability of nucleolus organizer region (nor) size in neurospora crassa. by pulsed-field gel electrophoresis, we followed in genetic crosses the size of the normal or "terminal" nors and the size of a small interstitial nor. tetrad analysis revealed that changes in nor size occur frequently in the sexual phase. moreover, most size changes occurred in the period between fertilization and meiosis, although some changes occurred during and after meiosis. unexpectedly, in ...19892527181
fast light-regulated genes of neurospora crassa.several physiological reactions including the sexual differentiation of the ascomycete neurospora crassa are triggered by blue light. mutants in the white-collar genes wc-1 and wc-2 are blind for all the blue light effects tested so far. we have previously shown that blue light induces some translatable mrnas at different times after beginning the illumination. here we report the cdna cloning of four genes that are induced by blue light. induction of these transcripts is temporally ordered (lag ...20082527354
the vacuolar atpase of neurospora crassa contains an f1-like structure.we have explored the structure and subunit composition of the vacuolar atpase of neurospora crassa by investigating the effects of nitrate. inhibition of enzyme activity by nitrate was correlated with dissociation of a complex of peripheral polypeptides from the integral membrane part of the enzyme. surprisingly, this nitrate-induced release of subunits occurred only when nucleotides such as adp, atp, or itp were present. atpase inhibitors that have been proposed to act at the active site preven ...19892527854
epistasis, photoreactivation and mutagen sensitivity of dna repair mutants upr-1 and mus-26 in neurospora crassa.double mutants were constructed combining mus-26, formerly designated uvs-(sa3b), with other uv-sensitive mutants. tests of sensitivity of these double mutants to uv and to chemical mutagens revealed that mus-26 and upr-1 belong to the same epistatic group. the uv dose-response curve of mus-26 showed a characteristic plateau in the range of 100-200 j/m2. the same characteristic was also shown in the dose-response curves of upr-1 and the double mutant, upr-1 mus-26. photoreactivation of uv damage ...19892528064
luminescence emission from neurospora copper metallothionein. time-resolved studies.the luminescence lifetime of cu-metallothionein from the fungus neurospora crassa has been studied by the frequency-domain emission technique. lifetimes of 10.3 and 3.4 microseconds have been found for the protein in the absence and in the presence of oxygen respectively. binding of hg(ii) results in a quenching of the luminescence correlated to the shortening of lifetime to 0.3-0.4 microsecond. no quenching by oxygen is found for the hg(ii)-cu-metallothionein adduct. by analogy to model compoun ...19892528343
early response and induced tolerance to cycloheximide in neurospora crassa.incubation of neurospora crassa mycelia with low doses of cycloheximide induces the expression of several genes. after 6 h in the presence of cycloheximide, mycelia become tolerant to further additions of the drug and the rate of protein synthesis exhibits a lower sensitivity to it. the polypeptide pattern is indicative of a stress situation.19892528413
development of an in vitro transcription system for neurospora crassa mitochondrial dna and identification of transcription initiation sites.we have developed an in vitro transcription system for neurospora crassa mitochondrial dna (mtdna) and used it to identify transcription initiation sites at the 5' ends of the genes encoding the mitochondrial small and large rrna and cytochrome b (cob). the in vitro transcription start sites correspond to previously mapped 5' ends of major in vivo transcripts of these genes. sequences around the three transcription initiation sites define a 15-nucleotide consensus sequence, 5'-ttagara(t/g)g(t/g) ...19892528684
molecular cloning and regulatory analysis of the arylsulfatase structural gene of neurospora crassa.the ars-1+ gene of neurospora crassa encodes the enzyme arylsulfatase. ars-1+ is in a group of highly regulated sulfur-related structural genes that are expressed under conditions of sulfur limitation and are under coordinate control of the cys-3+ and scon+ regulatory genes. the ars-1+ gene was cloned by chromosome walking from the qa gene cluster, using a lambda library. cotransformation of an n. crassa ars-1 mutant with the isolated lambda clones and the benomyl resistance gene, followed by as ...19892528685
isolation of a gene that down-regulates nitrate assimilation and influences another regulatory gene in the same system.glutamine is the preferred source of nitrogen of neurospora crassa. in its presence and that of the gene product of ms5 (nmr-1), the fungus represses the assimilation of less preferred forms of nitrogen, such as nitrate. in the absence of glutamine and the presence of the product of gene nit-2, less preferred forms of nitrogen are assimilated as long as a specific pathway for their assimilation is induced. we report here the isolation, from a cosmid bank, of a gene that complements ms5 and can a ...19892528690
a unique low frequency raman band associated with metal binding to metallothionein.we find that the low frequency raman spectrum of zn(ii) metallothionein has a single prominent band at 138 cm-1 which is absent from the raman spectrum of the metal-free protein. this feature is also found for cd(ii) binding to both of the independent metallothionein domains and the metallothionein from neurospora crassa. tco(iii) coordination to metallothionein results in a similar raman band which is also found for the complex (ph4as)[reo(sch2ch2s)2]. by comparing these results to literature d ...19892528950
evidence for an essential histidine residue in the neurospora crassa plasma membrane h+-atpase.the neurospora crassa plasma membrane h+-atpase is rapidly inactivated in the presence of diethyl pyrocarbonate (dep). the reaction is pseudo-first-order showing time- and concentration-dependent inactivation with a second-order rate constant of 385-420 m-1.min-1 at ph 6.9 and 25 degrees c. the difference spectrum of the native and modified enzyme has a maximum near 240 nm, characteristic of n-carbethoxyhistidine. no change in the absorbance of the inhibited atpase at 278 nm or in the number of ...19892528992
premeiotic disruption of duplicated and triplicated copies of the neurospora crassa am (glutamate dehydrogenase) gene.premeiotic inactivation of duplicated sequences (the rip phenomenon of selker et al.) was studied by tetrad analysis using ectopic copies of am+ (coding for nadp-specific glutamate dehydrogenase) and a missense allele am3, coding for a distinctive form of the enzyme, at the normal locus. in duplication crosses either both gene copies were inactivated or neither. two inactivated am3 derivatives were shown to have undergone methylation and numerous base-pair changes, reflected in losses and gains ...19892529044
isolation and characterization of the tyrosinase gene from neurospora crassa.a precursor form of neurospora crassa tyrosinase has been identified by western transfer from crude protein extracts and by immunoprecipitation of in vitro translated tyrosinase mrna. the molecular weight of protyrosinase (75,000) exceeds that of mature tyrosinase (46,000) by about 50%. in order to deduce the primary structure and the nature of the extension, the tyrosinase gene was cloned. poly(a) rna isolated from tyrosinase-induced cultures of n. crassa was used as a template for cdna synthes ...19892529259
translocation arrest by reversible folding of a precursor protein imported into mitochondria. a means to quantitate translocation contact sites.passage of precursor proteins through translocation contact sites of mitochondria was investigated by studying the import of a fusion protein consisting of the nh2-terminal 167 amino acids of yeast cytochrome b2 precursor and the complete mouse dihydrofolate reductase. isolated mitochondria of neurospora crassa readily imported the fusion protein. in the presence of methotrexate import was halted and a stable intermediate spanning both mitochondrial membranes at translocation contact sites accum ...19892529262
molecular and classical genetic analyses of his-3 mutants of neurospora crassa. i. tests for allelic complementation and specific revertibility.a collection of 81 his-3 mutants of neurospora crassa was analyzed in assays for allelic complementation and specific revertibility. in these studies, the linearity of the complementation map of the his-3 cistron (webber, 1965) was confirmed and mutants were classified as complementing with non-polarized or polarized complementation patterns, or non-complementing. in the assays for spontaneous or induced revertibility, 89% (71/80) of the mutants reverted either spontaneously or after treatment w ...19892529437
x-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of neurospora crassa. iv. irreparable mutants of genotype ad-3a and ad-3b result from multilocus deletion and an unexpectedly high frequency of multiple-locus mutations.the induction of specific-locus mutations in the ad-3 region of neurospora crassa after x-irradiation was studied in a two-component heterokaryon to determine: (1) the ratio of reparable ad-3 mutants (presumed gene/point mutations, designated ad-3r) to irreparable ad-3 mutants (presumed multilocus deletions, designated ad-3ir), and (2) the induction kinetics of each class (webber and de serres, 1965). more extensive genetic tests made subsequently (de serres, 1989a) on the 832 x-ray-induced spec ...19892529438
a cycloheximide-inducible gene of neurospora crassa belongs to the cytochrome p-450 superfamily. 19892529480
oxidation of neurospora crassa nadp-specific glutamate dehydrogenase by activated oxygen species.the glutamine synthetase and the nadp-specific glutamate dehydrogenase activities of neurospora crassa were lost in a culture without carbon source only when in the presence of air. glutamine synthetase was previously reported to be liable to in vitro and in vivo inactivation by activated oxygen species. here we report that nadp-specific glutamate dehydrogenase was remarkably stable in the presence of activated oxygen species but was rendered susceptible to oxidative inactivation when chelated i ...19892530208
classical and molecular genetic analyses of his-3 mutants of neurospora crassa. ii. southern blot analyses and molecular mechanisms of mutagenicity.previous studies (overton et al., mutation res., 1989) on specific revertibility of 81 his-3 mutants have shown a correlation between complementation pattern and presumed genetic alteration similar to that shown by ad-3b mutants. in the present study, restriction enzyme analyses were used to further characterize the genetic alterations in individual his-3 mutants. the restriction fragment banding patterns of the majority of mutants were identical with that shown by wild-type 74-or23-1a and were ...19892530448
stereoselective arginine binding is a phylogenetically conserved property of group i self-splicing rnas.we have examined the reaction of gtp with rna polymerase transcripts containing the self-splicing rna precursors from the neurospora crassa cob1 intron, and from introns in the suny, nrdb and td genes of bacteriophage t4. in each case, we find a low km for gtp (between 0.8 and 11 microm), accompanied by competitive inhibition of the gtp reaction by l-arginine, as was found for the previously examined tetrahymena nuclear pre-rrna intron. trials with the 20 standard amino acids show that inhibitio ...19892531082
nucleotide sequence of pho-4+, encoding a phosphate-repressible phosphate permease of neurospora crassa.the nucleotide (nt) sequence of the neurospora crassa pho-4+ gene, which encodes a phosphate-repressible phosphate permease, has been determined. the gene specifies a protein of 590 amino acids (aa) and contains two introns. two rna transcripts of 3.3 and 2.4 kb have been identified, and transcription start points (tsp) and termination sites and/or processing sites have been located. the 3.3-kb message is initiated about 890 nt upstream from the tsp for the 2.4-kb transcript. a hydropathy profil ...20082531109
molecular cloning and expression in saccharomyces cerevisiae and neurospora crassa of the invertase gene from neurospora crassa.a plasmid (named pcn2) carrying a 7.6 kb bamhi dna insert was isolated from a neurospora crassa genomic library raised in the yeast vector yrp7. saccharomyces cerevisiae suco and n. crassa inv strains transformed with pnc2 were able to grow on sucrose-based media and expressed invertase activity. saccharomyces cerevisiae suco (pnc2) expressed a product which immunoreacted with antibody raised against purified invertase from wild type n. crassa, although s. cerevisiae suc+ did not. the cloned dna ...19892531138
unstable mitochondrial dna in natural-death nuclear mutants of neurospora crassa.the natural-death mutant of neurospora crassa has an accelerated senescence phenotype caused by a recessive mutation, nd, in a nuclear gene that is located in linkage group i. an examination of mitochondrial functions, however, revealed that the mutant has phenotypic and molecular defects similar to those commonly associated with maternally transmitted fungal senescence syndromes, including (i) deficiencies in cytochromes aa3 and b; (ii) a deficit in small subunits of mitochondrial ribosomes, an ...20082531276
a natural case of rip: degeneration of the dna sequence in an ancestral tandem duplication.5s rrna genes of neurospora crassa are generally dispersed in the genome and are unmethylated. the xi-eta region of oak ridge strains represents an informative exception. most of the cytosines in this region, which consists of a diverged tandem duplication of a 0.8-kilobase-pair segment including a 5s rrna gene, appear to be methylated (e. u. selker and j. n. stevens, proc. natl. acad. sci. usa 82:8114-8118, 1985). previous work demonstrated that the xi-eta region functions as a portable signal ...20082531278
acid phosphatase (ec 3.1.3.2) synthesis by phosphorus regulatory mutant strains of neurospora crassa.1. even though altered forms of acid phosphatase ii were synthesized by the mutant strains nuc-1a and nuc-2a of n. crassa, their synthesis was independent of exogenous phosphate concentrations. 2. synthesis of acid phosphatase i by nuc-2a was also insensitive to exogenous phosphate concentrations. when nuc-1a was grown on a low-phosphate medium, it also produced a heat-labile acid phosphatase in addition to a i-like acid phosphatase. i-like acid phosphatase was not detected in the mycelium of th ...19892531620
sensitivity to cyclosporin a is mediated by cyclophilin in neurospora crassa and saccharomyces cerevisiae.cyclosporin a, a cyclic fungal undecapeptide produced by tolypocladium inflatum, is a potent immunosuppressive drug originally isolated as an antifungal antibiotic. cyclosporin a (csa) is widely used in humans to prevent rejection of transplanted organs such as kidney, heart, bone marrow and liver. the biochemical basis of csa action is not known: its primary cellular target has been suggested to be calmodulin, the prolactin receptor or cyclophilin, a csa-binding protein originally isolated from ...19892531848
regulation of the nuclear genes encoding the cytoplasmic and mitochondrial leucyl-trna synthetases of neurospora crassa.we show that the nuclear genes for the cytoplasmic and mitochondrial leucyl-trna synthetase (leurs) of neurospora crassa are distinct in their encoded proteins, codon usage, mrna levels, and regulation. the 4.2-kilobase-pair region representing the structural gene for cytoplasmic leurs and flanking regions has been sequenced. the positions of the 5' and 3' ends of mrna and of a single 62-base-pair intron have been mapped. the methionine-initiated open reading frame encoded a protein of 1,123 ami ...19892532300
preparation of neurospora crassa chromosomes from a cell wall-less strain. 19892532324
amino acids and peptides. xxiv. synthesis of neurospora crassa metallothionein and related cysteine-containing peptides and examination of their heavy metal-binding properties.a pentacosapeptide corresponding to the entire amino acid sequence of neurospora crassa metallothionein and several related cysteine-containing peptides were synthesized by the conventional solution method and their heavy metal-binding properties were examined. the cu2+- or cu+-binding properties of the various peptides were similar to each other, whereas the cd2+-binding properties of these peptides were fairly structure-dependent.20072532570
bialaphos resistance as a dominant selectable marker in neurospora crassa.conidia of neurospora crassa are sensitive to the herbicide bialaphos at concentrations of 160 mg/l in westergaard's or fries' minimal media. plasmid pja4 was constructed by inserting a truncated bar gene from streptomyces hygroscopicus fused to the his-3 promoter from n. crassa into puc19. the bar gene in plasmid pja4 confers resistance to bialaphos when transformants are selected on a medium containing bialaphos. the bar gene can be used as an additional dominant selectable marker for transfor ...19892532965
bioelectrorheological model of the cell. 2. analysis of creep and its experimental verification.the electrorheological model of the cell proposed in part 1 of this work was used to analyze changes in time of the shape of a cell acted on by a constant-amplitude external alternating electric field, with lossiness of the media taken into account. shear stress in the cell membrane was determined. this model was then subjected to preliminary experimental verification using neurospora crassa (slime) spheroplasts subjected to an external alternating electric field of constant frequency (3 mhz) an ...19892533955
an ethidium bromide induced mutant of neurospora crassa defective in mitochondrial dna.slow growing mutants of neurospora crassa were obtained by ethidium bromide treatment of the wild type strain. a particular mutant er-3 showed stopper phenotype accompanied by deficient cytochrome spectra. the mutant showed an altered restriction pattern of the mtdna which indicated a deletion of 25,000 bp. the phenotype of the ethidium bromide induced mutant er-3 seem to be related to the loss of several essential genes due to a deletion in its mtdna.19892534062
secretion of an mr 60000 protein by benomyl-treated cells of neurospora crassa.in the presence of the microtubule inhibitor benomyl at micron concentrations, cells of neurospora crassa wild type strain st. lawrence 74a were found to secrete high amounts of an mr 60 000 protein into the culture medium (about 35 micrograms/ml after a 12 h treatment). the secretion also occurred after treatment with the other antitubulin drugs carbendazim (mbc), nocodazole, thiabendazole, and griseofulvin. this secretion is apparently induced by the specific action of benomyl on n. crassa bet ...19892534075
iron limitation and its effect on membrane proteins and siderophore transport in neurospora crassa.cells of the fungus neurospora crassa were grown under iron-deficient and iron-sufficient conditions and their plasma membrane proteins were compared. three strains were studied: n. crassa 74a (wild type), a siderophore-free mutant n. crassa (arg-5 ota aga) as well as a 'slime' variant of n. crassa which lacks a cell wall. plasma membranes were purified, solubilized and analyzed by one-dimensional sds/polyacrylamide gel electrophoresis yielding approximately 50 distinct protein bands with molecu ...19892534965
[antifungal activity of 5-benzilidene pyrrolone and furanone derivatives].the antifungal activity against neurospora crassa of some 5-benzilidene pyrrolone and furanone derivatives was realised. relations between the structure and this biological activity are established with fujita-ban and hansch methods. the preponderant part of lipophilicity, resonance effect and e or z configurations have been showed.19892535109
phase determination of the circadian rhythm of conidiation in heterocaryons between two out-of-phase mycelia in neurospora crassa.neurospora grows vegetatively as a syncytium in which multiple nuclei exist within a connected cytoplasm. because of the ability of separate and distinct mycelia to fuse, the possibility exists of generating heterocaryotic cultures in which the nuclei and cytoplasms of two different strains are comingled into the same syncytium. we have used such heterocaryons, in which the component parts differed with respect to their circadian clock phase, to examine whether or not clock-dominant phases exist ...19892535268
isolation of a transposable element from neurospora crassa.a neurospora crassa strain from adiopodoumé, ivory coast, contains multiple copies of a transposable element, tad. the element was detected as a 7-kilobase insertion in two independently isolated spontaneous forward mutants of the am (glutamate dehydrogenase) gene. laboratory strains do not contain tad. all progeny from crosses of the adiopodoumé strain to laboratory strains contain multiple copies. when the element was inserted in am, target sequences of 14 and 17 base pairs were duplicated in ...19892538822
evidence for three differentially regulated catalase genes in neurospora crassa: effects of oxidative stress, heat shock, and development.genetic and biochemical studies demonstrated that neurospora crassa possesses three catalases encoded by three separate structural genes. the specific activities of the three enzymes varied in response to superoxide-mediated stress, heat shock, and development. the three loci, which we designated cat-1, cat-2, and cat-3, map to the right arms of chromosomes iii, vii, and iii, respectively. the cat-1-encoded enzyme (designated cat-1; estimated molecular weight, 315,000; pi 5.2) was the predominan ...19892540152
cytochrome oxidase subunit v gene of neurospora crassa: dna sequences, chromosomal mapping, and evidence that the cya-4 locus specifies the structural gene for subunit v.the sequences of cdna and genomic dna clones for neurospora cytochrome oxidase subunit v show that the protein is synthesized as a 171-amino-acid precursor containing a 27-amino-acid n-terminal extension. the subunit v protein sequence is 34% identical to that of saccharomyces cerevisiae subunit v; these proteins, as well as the corresponding bovine subunit, subunit iv, contain a single hydrophobic domain which most likely spans the inner mitochondrial membrane. the neurospora crassa subunit v g ...19892540423
amino acid sequence of the alpha and beta subunits of methanosarcina barkeri atpase deduced from cloned genes. similarity to subunits of eukaryotic vacuolar and f0f1-atpases.the atpa and atpb genes coding for the alpha and beta subunits, respectively, of membrane atpase were cloned from a methanogen methanosarcina barkeri, and the amino acid sequences of the two subunits were deduced from the nucleotide sequences. the methanogenic alpha (578 amino acid residues) and beta (459 amino acid residues) subunits were highly homologous to the large and small subunits, respectively, of vacuolar h+-atpases; 52% of the residues of the methanogenic alpha subunit were identical ...19892544575
studies on the active site of the neurospora crassa plasma membrane h+-atpase with periodate-oxidized nucleotides.the neurospora crassa plasma membrane h+-atpase is inactivated by the periodate-oxidized nucleotides, oatp, oadp, and oamp, with oamp the most effective. inhibition of the atpase is essentially irreversible, because sephadex g-50 column chromatography of the oamp-treated atpase does not result in a reversal of the inhibition. inhibition of the atpase by oamp is protected against by the h+-atpase substrate atp, the product adp, and the competitive inhibitors tnp (2',3'-o-(2,4,6-trinitrocyclohexad ...19892545685
restricted distribution of the tad transposon in strains of neurospora.a simple colony blot procedure was used to screen 336 neurospora strains for the presence of the transposable element tad. these strains included the standard laboratory wild types, all of the available neurospora isolates collected from the ivory coast, and all wild-collected neurospora crassa isolates available from the fungal genetics stock center. tad was found only in the strain of origin from adiopodumé, ivory coast, where it is present in multiple copies. three other strains of african or ...20082546685
the actions of neurospora endo-exonuclease on double strand dnas.neurospora crassa endo-exonuclease, an enzyme implicated in recombinational dna repair, was found previously to have a distributive endonuclease activity with a high specificity for single strand dna and a highly processive exonuclease activity. the activities of endo-exonuclease on double strand dna substrates have been further explored. endo-exonuclease was shown to have a low bona fide endonuclease activity with completely relaxed covalently closed circular dna and made site-specific breaks i ...20082546947
use of transformation to make targeted sequence alterations at the am (gdh) locus of neurospora.specific in vitro-generated insertion, replacement, and deletion mutations have been integrated near the chromosomal locus of am (nadp-specific glutamate dehydrogenase) of neurospora crassa. two approaches have been successful. one approach used am+-containing vectors capable of integrating at any site in the genome. this technique was used to introduce a specific 700 bp insertion near the am locus and to replace chromosomal sequences near am with plasmid dna. efficiency was low, however, and ma ...19892549376
ubiquitin expression in neurospora crassa: cloning and sequencing of a polyubiquitin gene.we have cloned and sequenced a polyubiquitin gene from neurospora crassa that is organized in a four repeat-tandem array. the first repeat contains a small intron and the last is fused to an extra glutamine codon. in northern blots, two rna species of 1.3 kb and 0.7 kb hybridize to the isolated clone. the larger ubiquitin (ubi) transcript accumulates after partial inhibition of protein synthesis with cycloheximide, and the smaller one preferentially accumulates in conidia after germination. unex ...19892549509
nucleotide sequence and regulation of expression of the aspergillus nidulans gdha gene encoding nadp dependent glutamate dehydrogenase.the nucleotide sequence of the aspergillus nidulans gdha gene encoding nadp linked glutamate dehydrogenase has been determined and northern blot analysis used to study the regulation of expression of this gene. the gdha gene is 1485 nucleotides long and, by comparison with the corresponding neurospora crassa am gene, has two putative introns of 53 nucleotides and a protein encoding region of 1380 nucleotides that codes for an inferred protein of 49.63 kda which shows regions of homology with glu ...19892550758
reconstitution of a light-stimulated adenylate cyclase from retina and neurospora crassa preparations. characterization of the heterologous systems using normal and degenerative retinas.adenylate cyclase catalytic subunits from neurospora crassa membranes may interact with regulatory factors from membranes of bovine retinal rod outer segments (pretreated with n-ethylmaleimide), reconstituting a heterologous system which, in the presence of light, is catalytically active in assay mixtures containing mgatp. maximal activation was observed at 550 nm. transducin-depleted retinal membranes were not capable of reconstituting the heterologous light-stimulated adenylate cyclase system. ...19892553402
isolation and characterization of a laccase-derepressed mutant of neurospora crassa.laccase from the ascomycete neurospora crassa is an inducible secretory enzyme. production of this enzyme is repressed in vegetative cultures but can be induced by treatment with low concentrations of cycloheximide. isolation and characterization of a derepressed mutant, the lah-1 mutant, that is capable of producing laccase in vegetative cultures without induction by cycloheximide are described. the lah-1 mutation is mapped between nit-2 and leu-3 on linkage group i, and it behaved as a recessi ...19892553675
[identification of human porins. ii. characterization and primary structure of a 31-lda porin from human b lymphocytes (porin 31hl)].we characterize and describe for the first time the primary structure of a human porin with the molecular mass of 31 kda derived from the plasmalemm of b-lymphocytes (porin 31hl). porin 31hl is shown to be a basic, channel forming membrane protein. the protein chain is composed of 282 amino acids with a relative molecular mass of 30641 da without derivatisation. it is not a glycoprotein. the n-terminus is acetylated. altogether the amino-acid sequence shows 56% hydrophilic or charged amino acids ...19892559745
isolation of everted plasma membrane vesicles from neurospora crassa and measurement of transport function. 19892561173
isolation of nit-4, the minor nitrogen regulatory gene which mediates nitrate induction in neurospora crassa.expression of nitrate reductase in neurospora crassa requires the positive action of nit-4, a pathway-specific regulatory gene, which mediates nitrate induction. we report the molecular cloning of the nit-4 gene and present results which suggest that the nit-4 gene is constitutively expressed to yield a low-abundance 2.2-kilobase transcript. these results indicate that the nit-2 major control gene and the nit-4 pathway-specific control gene independently regulate the expression of the nitrate as ...19892567729
identification and electron microscopic analysis of a chaperonin oligomer from neurospora crassa mitochondria.a 7-fold symmetric particle has been identified in neurospora crassa which is most probably the mitochondrial chaperonin. the particle, about 12 nm in diameter, appears in preparations of cytochrome reductase, and is shown to contain a 60 kd protein which cross-reacts with anti-groel antibodies. results of stem mass measurement suggest that the particle is composed of 14 subunits. a preliminary interpretation of the structure of the particle based on electron microscopy is given. its quaternary ...19892569968
cloning and analysis of the neurospora crassa gene for cytochrome c heme lyase.the cyt-2-1 mutant of neurospora crassa is deficient in cytochromes aa3 and c and in cytochrome c heme lyase activity (mitchell, m.b., mitchell, h.k., and tissieres, a. (1953) proc. natl. acad. sci. u.s.a. 39, 606-613; nargang, f.e., drygas, m.e., kwong, p.l., nicholson, d.w., and neupert, w. (1988) j. biol. chem. 263, 9388-9394). by rescue of the slow growth character of the cyt-2-1 mutant, we have cloned the cyt-2+ gene from a n. crassa genomic library using sib selection. analysis of the dna ...19892572587
nuclear gene for mitochondrial leucyl-trna synthetase of neurospora crassa: isolation, sequence, chromosomal mapping, and evidence that the leu-5 locus specifies structural information.we have isolated and characterized the nuclear gene for the mitochondrial leucyl-trna synthetase (leurs) of neurospora crassa and have established that a defect in this structural gene is responsible for the leu-5 phenotype. we have purified mitochondrial leurs protein, determined its n-terminal sequence, and used this sequence information to identify and isolate a full-length genomic dna clone. the 3.7-kilobase-pair region representing the structural gene and flanking regions has been sequenced ...19892574823
transformation by integration in podospora anserina. iii. replacement of a chromosome segment by a two-step process.we have developed in podospora anserina a two-step procedure for dna sequence replacement through transformation which might be applicable to other filamentous fungi. targeting of transforming dnas to their homologous locus is achieved provided a cosmid vector is used. southern blot analysis of genomic dnas from a set of transformants is presented. the data confirm that cosmids integrate into the chromosome through mostly homologous recombination which leads to a duplicated sequence separated by ...19892575706
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
effect of ph on the mutagenic and killing potencies of icr-170 in ad-3 tests of neurospora crassa. 20032579330
heterogeneity of 5s rna in fungal ribosomes.neurospora crassa has at least seven types of 5s rna genes (alpha, beta, gamma, epsilon, delta, zeta, and eta) with different coding regions. a high resolution gel electrophoresis system was developed to separate minor 5s rna's from the major 5s rna (alpha). a study of several neurospora crassa strains, four other species in the genus neurospora, members of two closely related genera, and three distantly related genera demonstrated that 5s rna heterogeneity is common among fungi. in addition, di ...19852579431
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
transformation in fungi.transformation with exogenous deoxyribonucleic acid (dna) now appears to be possible with all fungal species, or at least all that can be grown in culture. this field of research is at present dominated by saccharomyces cerevisiae and two filamentous members of the class ascomycetes, aspergillus nidulans and neurospora crassa, with substantial contributions also from fission yeast (schizosaccharomyces pombe) and another filamentous member of the class ascomycetes, podospora anserina. however, tr ...19892651864
two proteins encoded at the chla locus constitute the converting factor of escherichia coli chla1.molybdopterin (mpt) is not produced by the escherichia coli mutants chla1, chlm, or chln or by the neurospora crassa mutant nit-1. extracts of e. coli chla1 contain an activity, the converting factor, which is functionally defined by its ability to convert a low-molecular-weight precursor present in crude extracts of n. crassa nit-1 into molybdopterin in vitro. in this study, it has been shown that the converting factor consists of two associative proteins (10 and 25 kilodaltons [kda]) which can ...19892656653
acyl carrier protein is present in the mitochondria of plants and eucaryotic micro-organisms.proteins antigenically similar to the acyl carrier protein (acp) found in the mitochondria of neurospora crassa were detected by immunoblotting and radioimmunoassay techniques in mitochondria isolated from yeast, potatoes, and pea leaves. these mitochondrial proteins were similar to neurospora acp both in their electrophoretic mobility and in their unusual decrease in mobility upon reduction. authentic acp(s) show this type of change upon conversion of the acylated to the unacylated form. purifi ...19892680483
yeast cyclophilin: isolation and characterization of the protein, cdna and gene.cyclophilin (cph) has been isolated from the yeast saccharomyces cerevisiae, purified to homogeneity and partially sequenced. oligodeoxyribonucleotides deduced from this sequence were used to isolate the corresponding cdna and gene. an open reading frame coding for a 162-amino acid (aa) protein with a calculated mr of 17,392, was deduced from the nucleotide sequence. comparison between yeast and human cph shows a very high overall sequence conservation (65% aa homology). the binding of yeast cph ...19892687115
improved transformation efficiency of aspergillus niger using the homologous niad gene for nitrate reductase.aspergillus niger transformation frequencies of up to 1,176 transformants per micrograms dna were achieved using the plasmid vector psta10 containing the a. niger nitrate reductase structural gene. analysis of genomic endonuclease cleaved dna from nitrate utilising transformants by dna hybridisation, showed that most integration events are as a result of homologous recombination. the niad transformation system was used successfully for the introduction of the unselected escherichia coli fusion g ...19892791035
molecular characterization of trp1, a gene coding for tryptophan synthetase in the basidiomycete coprinus cinereus.we utilized a cloned gene (trp5) encoding tryptophan synthetase (tsase) from saccharomyces cerevisiae to identify and clone the corresponding gene (trp1) from the basidiomycete coprinus cinereus. the primary nucleotide (nt) sequence of this gene was determined and compared to sequences from other filamentous fungi, as well as to other genes coding for tsase. a transformation assay was used to demonstrate that 321 nt, which do not include caat or tataaa elements and precede the translation initia ...19892806911
deficiency in mrna splicing in a cytochrome c mutant of neurospora crassa: importance of carboxy terminus for import of apocytochrome c into mitochondria.molecular cloning and characterization of cytochrome c cdna clones of neurospora crassa wild-type (74a) and a cytochrome c-deficient mutant (cyc1-1) are described. southern blot analysis of genomic dna indicates that only one cytochrome c gene exists in the n. crassa genome. the cdna sequence of the wild-type cytochrome c confirmed the previously determined protein sequence. sequence analysis of the cyc1-1 cdna for cytochrome c revealed the presence of a larger open reading frame, owing to the p ...19872820723
characterization of pi-repressible enzymes secreted in culture media by neurospora crassa wild-type cells and null-type mutants.in wild-type mycelial cultures of neurospora crassa under pi-limited conditions, alkaline phosphatase, cyclic phosphodiesterases i, ii, iii, and iv, 5'-nucleotidase, acid and alkaline nucleases, rnase n1, and a newly detected endonuclease were secreted into the culture media. these enzymes were either not produced or were produced in very reduced levels in mutants nuc-1, -2, -3, -4, -5, -6, and -7 and cpd-4. the proteins were examined by polyacrylamide gel electrophoresis in a manner which allow ...19872820943
the molybdenum iron-sulphur protein from desulfovibrio gigas as a form of aldehyde oxidase.the molybdenum iron-sulphur protein originally isolated from desulfovibrio gigas by moura, xavier, bruschi, le gall, hall & cammack [(1976) biochem. biophys. res. commun. 72, 782-789] has been further investigated by e.p.r. spectroscopy of molybdenum(v). the signal obtained on extended reduction of the protein with sodium dithionite has been shown, by studies at 9 and 35 hgz in 1h2o and 2h2o and computer simulations, to have parameters corresponding to those of the slow signal from the inactive ...19872821990
antibiotic-induced derepression of the nad-specific glutamate dehydrogenase of neurospora crassa.the catabolic, nad-specific glutamate dehydrogenase (nad-gdh) of neurospora crassa is under carbon catabolite repression. cells grown on a glycolytic carbon source, such as sucrose, have low basal levels of enzyme activity. treatment of repressed cells with either polymyxin b or amphotericin b resulted in derepression of nad-gdh. derepression at the transcriptional level occurred very rapidly (within 30 min) in response to polymyxin b addition but reached a plateau within 2 h. amphotericin b-ind ...19872822659
control of nucleotide and erythroascorbic acid pools by cyclic amp in neurospora crassa.udpglucuronic acid and erythroascorbic acid were identified in extracts of the fungus neurospora crassa. the concentrations of these two compounds are estimated, in growing wild type n. crassa, to be about 0.10 and 0.28 mumol/ml of cell water, respectively. the pools of these two compounds are regulated by cyclic amp in neurospora, both being elevated in the cr-1, adenylate cyclase deficient mutant and both being lowered by exogenous cyclic amp. the pools of these two compounds are also elevated ...19872825802
purification and characterization of an endo-exonuclease from saccharomyces cerevisiae that is influenced by the rad52 gene.an endo-exonuclease has been purified from logarithmically growing cells of the yeast saccharomyces cerevisiae. identification and purification of this nuclease was facilitated by its being precipitable with an antibody raised against a previously described neurospora crassa endo-exonuclease (resnick, m. a., chow, t. y.-k. nitiss, j., and game, j. c. (1984) cold spring harbor symp. quant. biol. 49, 639-649 and t. y.-k. chow and m. a. resnick (1988) mol. gen. genet., in press). the enzyme which w ...19872826428
regulation of lactate/pyruvate ratios by cyclic amp in neurospora crassa.cyclic amp is thought to have a general role in stimulating the breakdown of carbohydrate reserves and subsequent glycolytic activity. this would be expected to increase the availability of reducing equivalents in the form of cytoplasmic nadh. the current study examines another potential reaction controlling cytoplasmic nadh in the fungus neurospora crassa, that of lactate dehydrogenase, to determine whether it is also regulated by cyclic amp. the cr-1, adenylate cyclase and cyclic amp-deficient ...19882827675
nitrobacter winogradskyi cytochrome a1c1 is an iron-sulfur molybdoenzyme having hemes a and c.cytochrome a1c1 (nitrite-cytochrome c oxidoreductase) purified from nitrobacter winogradskyi (formerly n. agilis) contained molybdenum, non-heme iron, and acid-labile sulfur in addition to hemes a and c; it contained 1 mol of heme a, 4-5 g atoms of non-heme iron, 2-5 g atoms of acid-labile sulfur, and 1-2 g atoms of molybdenum per mol of heme c, but did not contain copper. the fluorescence spectra of the molybdenum cofactor derivative prepared from cytochrome a1c1 were very similar to those of t ...19872828343
isolation and analysis of the neurospora crassa cyt-21 gene. a nuclear gene encoding a mitochondrial ribosomal protein.the neurospora crassa nuclear mutant cyt-21-1 (originally 297-24; pittenger, t.h., and west, d.j. (1979) genetics 93, 539-555) has a defect leading to gross deficiency of mitochondrial small ribosomal subunits. here, we have cloned the cyt-21+ gene from a n. crassa genomic library, using the sib selection procedure (akins, r. a., and lambowitz, a. m. (1985) mol. cell biol. 5, 2272-2278). the genomic clone contains a short split gene encoding a basic protein of 107 amino acid residues. this prote ...19882830266
a 3' splice site mutation in a nuclear gene encoding a mitochondrial ribosomal protein in neurospora crassa.we showed previously that the cyt-21+ gene of neurospora crassa encodes a mitochondrial ribosomal protein homologous to escherichia coli ribosomal protein s-16 (kuiper, m. t. r., akins, r. a., holtrop, m., de vries, h., and lambowitz, a. m. (1988) j. biol. chem. 263, 2840-2847). a mutation in this gene, cyt-21-1, results in deficiency of mitochondrial small ribosomal subunits and small rrna (collins, r. a., bertrand, h., lapolla, r. j., and lambowitz, a. m. (1979) mol. gen. genet. 177, 73-84). i ...19882830267
an endo-exonuclease activity of yeast that requires a functional rad52 gene.extracts of rad+ and radiation-sensitive (rad) mutants of the yeast saccharomyces cerevisiae were examined for total mg2+-dependent alkaline deoxyribonuclease activity and the presence of a nuclease that crossreacts immunologically with an antiserum raised against an endo-exonuclease from neurospora crassa, an enzyme exhibiting both deoxyribo- and ribonuclease activities. no significant differences were observed in total deoxyribonuclease activity between rad+ and rad mutants. the antibody preci ...19882830467
inversions and recombinations in mitochondrial dna of the (sg-1) cytoplasmic mutant in two neurospora species.the mitochondrial dnas of [sg-1] cytoplasmically-mutant and wild-type strains of neurospora crassa and neurospora sitophila were examined by comparative restriction endonuclease analyses. the mtdna of n. sitophila wild type of whitehouse differs from type ii mtdna of n. crassa by insertions of 3.3 kb in ecori-9, and 1.2 kb in ecori-3, and a deletion of 1.1 kb in ecori-5. these dna heteromorphisms provided convenient markers for tracing n. crassa [sg-1] mtdna during and after its transfer into n. ...19862832078
conservation of a long open reading frame in two neurospora mitochondrial plasmids.the nucleotide sequence of a specific region of the mitochondrial plasmid from the neurospora intermedia varkud-lc strain was determined. analysis of the sequence revealed the presence of a long (up to 710 amino acids) orf. this orf is almost identical to a previously characterized orf in the mitochondrial plasmid from the neurospora crassa mauriceville-lc strain. when the orfs from the two plasmids are compared over their entire length of 2,133 bp, only 34 nucleotide substitutions are found (gr ...19862832686
isolation and identification of the aspergillus nidulans gdha gene encoding nadp-linked glutamate dehydrogenase.the neurospora crassa am gene was used as a heterologous probe to identify clones from two independently constructed aspergillus nidulans gene libraries. these clones have a common hindiii 1.85 kb fragment. this a. nidulans nucleotide stretch hybridises to a n. crassa 2.7 kb bamhi fragment of wild type dna but not to a co-migrating fragment from the dna of the n. crassa am132 deletion mutant. one a. nidulans clone was shown to complement the n. crasse am132 deletion strain. the n. crassa transfo ...19862834076
characterization of inl+ transformants of neurospora crassa obtained with a recombinant cosmid-pool.we constructed a neurospora crassa gene library in a cosmid vector and used the cosmid-pool dna to transform an inl, rg neurospora crassa strain to inositol prototrophy. the inl+ colonies obtained in this experiment proved to be integrative type transformants. genetic analysis revealed that the integration event occurred at or near the inl locus. in one of the transformants the inl+ trait exhibited mitotic and meiotic instability. in hybridization experiments free plasmids were detected in the f ...19862834083
transformation of neurospora crassa with the trp-1 gene and the effect of host strain upon the fate of the transforming dna.neurospora trp-1+ transformants, obtained by transforming a trp-1 inl strain with plasmid dna containing the wild type trp1+ gene, were characterized by genetic and southern blot analyses. the transforming trp-1 gene integrated at or near the resident site in all of the trp-1+ transformants obtained with circular dna or dna cut within the trp-1 coding region. the frequency of homologous integration decreased substantially when the donor dna was cleaved outside the trp-1 coding region. the transf ...19882834105
identification and isolation of a putative permease gene in the quinic acid utilization (qut) gene cluster of aspergillus nidulans.mutations in the qutd gene of aspergillus nidulans cause the loss of ability to grow upon quinic acid as sole carbon source in media at normal ph 6.5 and failure to induce three enzyme activities specifically required for metabolism to protochatechuic acid. all 9 qutd mutants recovered are recessive and have been found to be ph sensitive, growing strongly on quinic acid media at ph 3.5 and producing significant induced enzyme activities. these properties are consistent with the hypothesis that t ...19872835177
neurospora crassa nuclear genome contains analogy of saccharomyces cerevisiae genes for ribosomal rna processing.neurospora crassa wild type genome shows dna sequences which are homologous to the sequences present in the rrna processing genes of the yeast saccharomyces cerevisiae. five such processing genes from yeast, viz., rna1 through rna5, cloned in plasmid pbr322 were transformed in escherichia coli strain le392. southern blots containing dnas from these clones were restricted with several restriction endonucleases along with dnas from lambda phage, rice (plant) and neuroblastoma (animal), were hybrid ...19872835180
sequence analysis of the ddpyr5-6 gene coding for ump synthase in dictyostelium discoideum and comparison with orotate phosphoribosyl transferases and omp decarboxylases.a dictyostelium discoideum dna fragment that complements the ura3 and the ura5 mutants of saccharomyces cerevisiae has been sequenced. it contains an open reading frame of 478 codons capable of encoding a polypeptide of molecular weight 52475. this gene, named ddpyr5-6, encodes a bifunctional protein composed of the orotate phosphoribosyl transferase (oprtase) and the orotidine-5'-phosphate decarboxylase (ompdecase) domains described for ump synthase in mammals. the existence of separate domains ...19882835631
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