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circadian rhythms in neurospora crassa: biochemistry and genetics. 19902147375
the nucleotide excision repair epistasis group in neurospora crassa.dna repair mutants in eucaryotes are normally assigned to three epistasis groups. each epistasis group represents a "pathway" for dna repair. the pathways are commonly designated (1) nucleotide excision repair, (2) recombination repair and (3) mutagenic repair. an excision repair epistasis group has been established in neurospora and the mutants assigned to this group should be limited in their ability to excise pyrimidine dimers and other bulky lesions from dna. using a pyrimidine dimer-specifi ...19902147402
cpc-2, a new locus involved in general control of amino acid synthetic enzymes in neurospora crassa.in neurospora crassa starvation for single amino acids leads to derepression of enzymes in many amino acid synthetic pathways. regulation occurs at the level of transcription via "general amino acid (or cross-pathway) control". in this paper a new regulatory gene, cpc-2, is described that specifies a positive, trans-acting effector involved in this control. this gene, located on linkage group vii, was identified by a recessive mutation, u142, which results in sensitivity for two amino acid analo ...19902147403
cytosolic calcium homeostasis in fungi: roles of plasma membrane transport and intracellular sequestration of calcium.cytosolic free calcium ([ca2+]c) has been measured in the mycelial fungus neurospora crassa with ca2(+)-selective microelectrodes. the mean value of [ca2+]c is 92 +/- 15 nm and it is insensitive to external ph values between 5.8 and 8.4. simultaneous measurement of membrane potential enables the electrochemical potential difference for ca2+ across the plasma membrane to be estimated as about -60 kj.mol-1-a value that cannot be sustained either by a simple ca2(+)-atpase, or, in alkaline condition ...19902147513
expression of tyrosinase in vegetative cultures of neurospora crassa transformed with a metallothionein promoter/protyrosinase fusion gene.wild-type neurospora crassa, strain singapore, was transformed with a n. crassa metallothionein promoter/protyrosinase fusion gene. transformants produced tyrosinase during vegetative growth, as determined by western analyses and activity assays. this is in sharp contrast to wild-type strains, where this enzyme is only expressed in situations of starvation or sexual differentiation. complete integration of a 400 bp metallothionein promoter-fragment leads to constitutive expression of protyrosina ...19902147580
the beta-tubulin gene of epichloë typhina from perennial ryegrass (lolium perenne).epichloë typhina is a biotrophic fungal pathogen which causes choke disease of pooid grasses. the anamorphic state, acremonium typhinum, is placed in the section albo-lanosa along with related, mutualistic, seed-disseminated endophytes. as an initial study of gene structure and evolution in epichloë and related endophytes, the beta-tubulin gene, tub2, of the perennial ryegrass choke pathogen (etprg) was cloned and sequenced. the coding sequence and the predicted beta-tubulin amino acid sequence ...19902147581
deletion analysis of domain independence in the trp1 gene product of neurospora crassa.the trifunctional trp1 gene from neurospora crassa (n-trp1) was subcloned into the yeast-escherichia coli shuttle vector yep13 and expressed in saccharomyces cerevisiae. the three activities of the n-trp1 gene product were detected in yeast mutants that lacked either n-(5'-phosphoribosyl) anthranilate (pra) isomerase or both the glutamine amidotransferase function of anthranilate synthase and indole-3-glycerol phosphate (ingp) synthase. the protein was detected on immunoblots only as the full le ...19902147978
nucleotide sequence of a neurospora crassa ribosomal protein gene. 19902147995
studies on the sedimentation behavior of the neurospora crassa plasma membrane h(+)-atpase synthesized in vitro and integrated into homologous microsomal membranes.rna transcripts that encoded the neurospora crassa plasma membrane h(+)-atpase (pma+), a polytopic integral membrane protein, and the pma+344, a truncated pma+ with the amino terminal 344 amino acids, were translated in a n. crassa in vitro system. the microsomal membranes integrated products were insensitive to extraction by na2co3 (ph 11.5). the velocity sedimentation behavior of the in vitro synthesized pma+ were examined under various conditions. the pma+ migrated on linear sucrose gradients ...19902148269
heat shock response in neurospora crassa: purification and some properties of hsp 80.the heat shock response of neurospora crassa was investigated. a 80-kilodalton heat shock protein (hsp 80) was purified to near homogeneity from heat-shocked mycelial extracts employing ammonium sulphate fractionation, gel filtration, and ion-exchange and affinity chromatography. it was observed to migrate as a single band on one-dimensional sodium dodecyl sulphate--polyacrylamide gels, with a molecular mass of approximately 83 kilodaltons (kda). on two-dimensional gels it resolved into four pol ...19902148482
genes expressed during conidiation in neurospora crassa: molecular characterization of con-13.asexual development in neurospora crassa proceeds through a series of discrete morphological stages that culminate in the production of dormant spores called conidia. changes in the pattern of gene expression parallel the morphological transformations associated with conidiation. as a prerequisite to the analysis of developmental gene expression in n. crassa, several genes of unknown function that are preferentially expressed during conidiation were isolated [berlin and yanofsky, mol. cell. biol ...19902148538
restricted activation of general amino acid control under conditions of glutamine limitation in neurospora crassa.in neurospora crassa limitation for single amino acids normally results in increased formation of enzymes required for amino acid synthesis via 'general amino acid control'. glutamine limitation, however, led to comparatively low and delayed derepression of enzyme synthesis. nitrate reductase activity increased steeply under these conditions confirming that de novo protein synthesis could occur. derepression levels were unaffected by addition of glutamine-derived metabolites. only small and dela ...19902148607
nucleotide sequence and dna recognition elements of alc, the structural gene which encodes allantoicase, a purine catabolic enzyme of neurospora crassa.the nitrogen regulatory circuit of neurospora crassa contains structural genes that encode nitrogen catabolic enzymes which are subject to complex genetic and metabolic regulation. this set of genes is controlled by nitrogen limitation, by specific induction, and by the action of nit-2, a major positive-acting regulatory gene, and nmr, a negative-acting control gene. the complete nucleotide sequence of alc, the gene that encodes allantoicase, a purine catabolic enzyme, is presented. the alc gene ...19902148685
induced expression of the aspergillus nidulans qute gene introduced by transformation into neurospora crassa.the qa-2 gene of neurospora crassa encodes catabolic dehydroquinase which catabolizes dehydroquinic acid to dehydroshikimic acid. the qute gene of aspergillus nidulans corresponds to the qa-2 gene of n. crassa. the plasmid peh1 containing the qute gene from a. nidulans was used to transform a qa-2- strain of n. crassa. in southern blot analyses, dnas isolated from these transformants hybridized specifically to the qute gene probe. northern blot analyses indicated that qute mrna was produced in t ...19902148798
analysis of conventional and in vitro generated mutants of nmr, the negatively acting nitrogen regulatory gene of neurospora crassa.the nmr gene is the major negative regulatory gene in the nitrogen control circuit of neurospora crassa, which, together with positive regulatory genes, governs the expression of multiple unlinked structural genes of the circuit. possible functional domains of the nmr protein were investigated by mutational analyses using three different approaches. first, the polymerase chain reaction was used to clone the nmr locus from two conventional mutants, v2m304 and ms5, and the mutant amino acid codons ...19902148799
expression of a neurospora crassa metallothionein and its variants in escherichia coli.the neurospora crassa metallothionein (nc) synthesis gene was cloned and expressed in escherichia coli in two different expression vectors (ping2 and pua7), both under the regulation of the salmonella typhimurium arabinose operon. upon induction with arabinose, the ping2-nc vector expressed as inclusion body-localized arab'::nc fusion protein of 21 kilodaltons. the pua7-nc vector expressed a 5.3-kilodalton lpp::nc fusion protein anchored to the outer membrane of the cell. cells expressing the nc ...19902148862
purification and characterization of catalase from a facultative alkalophilic bacillus.catalase was purified to an electrophoretically homogeneous state from the facultative alkalophilic bacterium, bacillus yn-2000, and some of its properties were studied. its molecular weight was 282,000 and its molecule was composed of four identical subunits. the enzyme contained two protoheme molecules per tetramer. the enzyme showed an absorption spectrum of typical high-spin ferric heme with a peak at 406 nm in the oxidized form and peaks at 440, 559, and 592 nm in the reduced form. in contr ...19902149854
atp-induced protyrosinase synthesis and carboxyl-terminal processing in neurospora crassa.the effects of 3'-5' cyclic amp and atp upon tyrosinase induction in neurospora crassa were examined. northern analysis of total cellular rna revealed rapid de novo synthesis of protyrosinase after addition of these substances to stationary-phase mycelia. the maturation of protyrosinase in crude extracts of mycelia was followed by western analysis. polyclonal rabbit antiserum directed against the denatured carboxyl-terminal extension of protyrosinase does recognize the proform and several interm ...19902150229
generation of new functional mutant alleles by premeiotic disruption of the neurospora crassa am gene.in the further analysis of a cross in which the mis-sense allele, am3, of the neurospora crassa am (glutamate dehydrogenase) gene was present in one parent together with two ectopic wild-type gene copies, one ascus was identified in which the two ectopic copies had been inactivated by the rip process whereas the am3 allele continued to produce its characteristic enzyme variety in active, but heat-sensitive, form. the am3 allele had also acquired a new hindiii restriction site. it had no detectab ...19902150348
site-directed mutagenesis of the 'zinc finger' dna-binding domain of the nitrogen-regulatory protein nit2 of neurospora.the major nitrogen-regulatory gene nit-2 of neurospora crassa activates the expression of numerous unlinked structural genes which specify nitrogen-catabolic enzymes during conditions of nitrogen limitation. the nit-2 gene encodes a regulatory protein of 1036 amino acid residues with a single 'zinc finger' and a downstream basic region, which together may constitute a dna-binding domain. the zinc finger domain of the nit2 protein was synthesized in vitro and also expressed as a fusion protein in ...19902150539
premeiotic instability of repeated sequences in neurospora crassa.maintenance of a steamlined genome is probably important to a free-living fungus. the period between fertilization and karyogamy in the life cycle of neurospora and related fungi provides an ideal time for "genome-cleaning". premeiotic intrachromosomal recombination deletes tandem repeats at high frequency in both homothallic and heterothallic filamentous ascomycetes. this eliminates excess copies of tandemly repeated genes and at the same time favors their homogenization. heterothallic fungi su ...19902150906
aberrant mitochondrial processing of chimaeric import precursors containing subunits 8 and 9 of yeast mitochondrial atp synthase.a set of chimaeric precursors which contain the same leader sequences but different passenger proteins has been analyzed for the site of protease cleavage following import into yeast mitochondria. each precursor comprises the leader of neurospora crassa subunit 9 of mitochondrial atp synthase fused to subunit 8 or 9 of the corresponding yeast enzyme. precursors containing the first five residues of mature n. crassa subunit 9 interposed between the leader and the yeast passenger protein were clea ...19902151020
5-benzylidene pyrrolones. iv--synthesis and antifungal activity of some 5-benzylidene derivatives of 1,2-dimethyl-3-carbethoxy-pyrrol-4-one.in order to investigate the antifungal activity of pyrrolones, the synthesis of derivatives of 5-benzylidene-1,2,-dimethyl-3-carbethoxy-pyrrol-4-one was achieved by a one-step reaction. the condensation reaction was applied to the above-mentioned heterocycle and seven substituted benzaldehydes were obtained providing the entitled compounds, of which six are original. they have preferential e configuration. antifugal data against neurospora crassa in comparison with ketoconazole showed that many ...19902151022
sorting of precursor proteins between isolated spinach leaf mitochondria and chloroplasts.the precursors of the f1-atpase beta-subunits from nicotiana plumbaginifolia and neurospora crassa were imported into isolated spinach (spinacia oleracea l.) leaf mitochondria. both f1 beta precursors were imported and processed to mature size products. no import of the mitochondrial precursor proteins into isolated intact spinach chloroplasts was seen. moreover, the precursor of the 33 kda protein of photosynthetic water-splitting enzyme was not imported into the leaf mitochondria. this study p ...20072151717
mutations that affect circadian rhythms in neurospora crassa can alter the reduction of cytochromes by blue light.we have examined membrane fractions from mutant strains of neurospora crassa that have altered responses to blue light or have altered circadian rhythms. using an in vitro assay, we assessed whether the mutations affected the levels of photoreducible cytochromes. three of the mutant strains, prd-1, rib-1, and wc-1, were not qualitatively different from the wild type. the poky strain was found to have high concentrations of photoreducible cytochrome c. after removal of this cytochrome, however, t ...19902151931
[genetic engineering in filamentous fungi: cloning of the invertase gene from neurospora crassa].the invertase wild type gene of n. crassa was cloned into the yrp7 yeast vector. this recombinant plasmid was selected by functional complementation of an invertaseless mutant strain of s. cerevisiae. the isolated recombinant plasmid (named pnc2) carries a 7.6 kb bamhi dna fragment from n. crassa. the cloned dna hybridized with the n. crassa genomic dna and transformed an invertase mutant of n. crassa inv- to inv+. transformation of n. crassa inv- to inv+ seems to take at least two different int ...19902151941
neurospora endo-exonuclease is immunochemically related to the recc gene product of escherichia coli.immunochemical cross-reaction between the endo-exonuclease of neurospora crassa, an enzyme previously implicated in recombination and recombinational dna repair, and the recc-encoded polypeptide of escherichia coli has been detected by immunoblotting extracts of strains of e. coli having a deletion that includes the recbcd genes but carrying multicopy plasmids bearing all three of the recbcd genes or only one or two of these genes. it was predicted that homology would also be found at the amino ...19902152915
cis,cis-cyclohexane 1,3,5-triol polyphosphates release calcium from neurospora crassa via an unspecific ins 1,4,5-p3 receptor.we investigated the effects of new inositol 1,4,5-trisphosphate analogues on the release of ca2+ from isolated vacuoles of neurospora crassa. tri-o-butyryl-inositol 1,4,5-trisphosphate and a set of cis,cis-cyclohexane 1,3,5-triol bis-(cht-p2) and trisphosphates (cht-p3) gave an increase in free ca2+ as measured directly with fura-2, a ca2(+)-chelator. however, inositol 1,4-bisphosphate, 6-o-palmitoyl-inositol 4,5-bisphosphate and trans-cyclohexane 1,2-diol bisphosphate (trans chd-p2) did not ind ...19902154977
mitochondrial dna sequence analysis of the cytochrome oxidase subunit ii gene from podospora anserina. a group ia intron with a putative alternative splice site.a 5 kb region of the 95 kb mitochondrial genome of podospora anserina race s has been mapped and sequenced (1 kb = 10(3) base-pairs). this dna region is continuous with the sequence for the nd4l and nd5 gene complex in the accompanying paper. we show that this sequence contains the gene for cytochrome oxidase subunit ii (coii). this gene is 4 kb in length and is interrupted by a subgroup ib intron (1267 base-pairs (bp) in length) and a subgroup ia intron (1992 bp in length). this group ia intron ...19902157023
relationship of vector insert size to homologous integration during transformation of neurospora crassa with the cloned am (gdh) gene.we used lambda and plasmid vectors containing the am+ gene in an insert of from 2.7 to 9.1 kb, to transform am point mutant and deletion strains. a total of 199 transformants were examined with the potential to yield am+ transformants by homologous recombination. when we used vectors that had 9.1 kb of homology with the chromosomal dna, 30% of the transformants obtained were the result of homologous recombination regardless of whether the vector was a lambda molecule, a circular plasmid, or a pl ...19902157957
on the role of ca2(+)-calmodulin-dependent and camp-dependent protein phosphorylation in the circadian rhythm of neurospora crassa.pulses of some ca2+ channel blockers (dantrolene, co2+, nifedipine) and calmodulin inhibitors (chlorpromazine) lead to medium (maximally 5-9 h) phase shifts of the circadian conidiation rhythm of neurospora crassa. pulses of high ca2+, or of low ca2+, a ca2+ ionophore (a23187) together with ca2+, and other ca2+ channel blockers (la3+, diltiazem), however, caused only minor phase shifts. the effect of these substances (a 23187) and of different temperatures on the ca2+ release from isolated vacuo ...19902159489
endo-exonuclease of aspergillus nidulans.endo-exonuclease (ee) has been found in both active and inactive, but trypsin-activatable, forms in aspergillus nidulans. active ee was present mainly in nuclei, mitochondria, and vacuoles, while trypsin-activatable ee was mainly in the cytosol. the active form accounts for over 90% of the neutral deoxyribonuclease activity extracted from mycelia. a single strand (ss) dna-binding ee associated with a 28 kilodalton (kda) polypeptide was partially purified and characterized. it was found to closel ...19902161674
regulation of inorganic sulfate activation in filamentous fungi. allosteric inhibition of atp sulfurylase by 3'-phosphoadenosine-5'-phosphosulfate.atp sulfurylases from penicillium chrysogenum, penicillium duponti, aspergillus nidulans, and neurospora crassa are strongly inhibited by 3'-phosphoadenosine-5'-phosphosulfate (paps), the product of the second (adenosine-5'-phosphosulfate kinase-catalyzed) reaction in the two-step activation of inorganic sulfate. the v versus [paps] plots are sigmoidal. at physiological concentrations of mgatp (0.17-3 mm) and so4(2-) (0.4-10 mm), the [i]0.5 for paps inhibition of the p. chrysogenum enzyme is 35- ...19902162344
nucleotide sequence and nuclear protein binding of the two regulatory sequences upstream of the am (gdh) gene in neurospora.we have constructed a series of deletions in the 5' non-coding sequences of the cloned neurospora crassa am gene which specifies nadp specific glutamate dehydrogenase. all of the deletions begin at -4.4 kb with respect to the am transcription start site and extend for various distances toward the am gene. using vectors with a truncated fragment of the am gene, we introduced these deletions into the chromosome upstream of am by transformation. analysis of glutamate dehydrogenase expression in str ...19902164625
import into mitochondria of precursors containing hydrophobic passenger proteins: pretreatment of precursors with urea inhibits import.we have studied the import into isolated yeast mitochondria of three hydrophobic passenger proteins attached to the n-terminal cleavable presequence of mitochondrial atpase subunit 9 from neurospora crassa. one natural precursor (pn9) contained n. crassa subunit 9; two chimaeric precursors, n9l/y8-1 and n9l/y9-2, respectively contained yeast mitochondrial atpase subunits 8 and 9. in the absence of urea, pn9 and n9l/y8-1 are imported efficiently but n9l/y9-2 is not imported. after pretreatment of ...19902168755
biochemical, genetic and ultrastructural defects in a mitochondrial mutant (er-3) of neurospora crassa with senescence phenotype.the structural and functional abnormalities in a new respiratory deficient, mitochondrial senescence mutant er-3 of neurospora crassa are described. the mitochondrial mutant, which grows at a rate of only 10% of that of the wild type, was found deficient in all three cytochromes, and completely lacking in cytochromes aa3. cytochrome oxidase activity in the mutant mitochondria was only about 5% of the wild type mitochondria. however, the total whole cell respiration rate of the mutant was 33% gre ...19902169558
plant and fungus calmodulins are polyubiquitinated at a single site in a ca2(+)-dependent manner.in plants ca2+ plays a crucial role as second messenger. thus calmodulin is one of the most important signal transducing molecules for metabolic regulation in plants. previously we showed that bovine testis calmodulin can be covalently coupled at one site to ubiquitin in a ca2(+)-dependent manner in the presence of atp/mg2+ by ubiquityl-calmodulin synthetase. since calmodulin from spinach has 13 amino acid sequence differences to bovine calmodulin - two of them in ca2(+)-binding loops - it was u ...19902172031
tad, a line-like transposable element of neurospora, can transpose between nuclei in heterokaryons.the tad transposon of neurospora crassa appears to be a line-like element with very restricted distribution within the genus neurospora. when forced heterokaryons were constructed between strains which did and did not contain tad, the nuclei of the naive nuclear type rapidly acquired tad elements. the elements acquired by naive nuclei are active, since they can pass tad to other naive nuclei in subsequent heterokaryons. when heterokaryons are passaged by serial transfer, the load of acquired tad ...19902174012
spatial and biological characterisation of the complete quinic acid utilisation gene cluster in aspergillus nidulans.heterologous probing of restriction digests of chromosomal dna from aspergillus nidulans with radioactively labelled probes encoding dehydroshikimate dehydratase (qa-4) and a repressor gene (qa1-s) from neurospora crassa revealed a pattern of hybridisation inconsistent with an equivalent single copy of each gene in a. nidulans. screening of size-selected and total genome a. nidulans dna libraries allowed the isolation of four unique classes of sequence, two of which hybridised to the qa-4 probe, ...19902175387
import of adp/atp carrier into mitochondria: two receptors act in parallel.we have identified the yeast homologue of neurospora crassa mom72, the mitochondrial import receptor for the adp/atp carrier (aac), by functional studies and by cdna sequencing. mitochondria of a yeast mutant in which the gene for mom72 was disrupted were impaired in specific binding and import of aac. unexpectedly, we found a residual, yet significant import of aac into mitochondria lacking mom72 that occurred via the receptor mom19. we conclude that both mom72 and mom19 can direct aac into mit ...19902177474
the general mitochondrial matrix processing protease from rat liver: structural characterization of the catalytic subunit.a critical step in the import of nuclear-encoded precursor proteins into mitochondria involves proteolytic cleavage of their amino-terminal leader peptides by processing proteases found in the mitochondrial matrix. we report here the characterization of the general matrix processing protease from rat liver mitochondria. the final enzyme preparation consisted of two polypeptides, a catalytically active 55-kda subunit and a 52-kda one. to deduce the complete primary structure of the 55-kda subunit ...19902236012
the development of a heterologous transformation system for the cellulolytic fungus trichoderma reesei based on a pyrg-negative mutant strain.six uridine auxotroph mutants of trichoderma reesei qm 9414 were isolated by resistance to 5-fluoroorotic acid and one strain was identified as omp-decarboxylase negative (pyr-) by a radiometric enzyme assay. transformation to uridine prototrophy was achieved with the pyr4 gene of neurospora crassa (up to 1500 transformants/micrograms) and with pyra of aspergillus niger (700-800 transformants/micrograms). in many transformants the pyr+ function seems to be present as extrachromosomal dna. there ...19902245476
mycenon, a new metabolite from a mycena species ta 87202 (basidiomycetes) as an inhibitor of isocitrate lyase.mycenon (c11h5cl3o3), a new inhibitor of isocitrate lyase (ec 4.1.3.1) was isolated from the culture broth of a basidiomycete, mycena sp. mycenon is a novel chlorinated benzoquinone derivative which is also active against bacteria and fungi. malate synthase (ec 4.1.3.2) the second key enzyme of the glyoxylate cycle was not affected by mycenon. isocitrate lyase preparations from plants, bacteria and fungi were sensitive. the following ki-values for mycenon have been determined: ricinus communis, ...19902258323
expression in saccharomyces cerevisiae of a gene associated with cytoplasmic male sterility from maize: respiratory dysfunction and uncoupling of yeast mitochondria.we asked whether the mitochondrial t-urf13 gene, associated with the male sterility phenotype of t cytoplasm in maize, can be expressed in saccharomyces cerevisiae and whether this expression can mimic the effects observed in maize. we introduced the universal code equivalent of the t-urf13 gene into the s. cerevisiae nucleus by transformation and directed its translation product into mitochondria by means of a fusion with the targeting presequence from neurospora crassa at-pase subunit 9. we sh ...19902259341
effects of cell wall deficiency on the synthesis of polysaccharide-degrading exoenzymes: a study on mycelial and wall-less phenotypes of the fz; sg; os-1 ('slime') triple mutant of neurospora crassa.the production of exoenzymes which degrade cellulose, polygalacturonic acid and xylan was studied in mycelial and wall-less phenotypic derivatives of neurospora crassa obtained by vegetative selection applied to a single fz;sg;os-1 ('slime'-like) segregant (strain rcp-3) of a cross 'slime' x wild type. the unrelated stable 'slime' strain fgsc 1118 was also studied. the synthesis of polysaccharide-degrading enzymes was normally induced by polysaccharidic substrates and was sensitive to carbon-cat ...19902262786
an evolutionary comparison of acinetobacter calcoaceticus trpf with trpf genes of several organisms.the deduced amino acid sequence of acinetobacter calcoaceticus n-(5'-phosphoribosyl) anthranilate isomerase (prai), which is coded by trpf, was compared with trpf of caulobacter crescentus, escherichia coli, bacillus subtilis, saccharomyces cerevisiae, neurospora crassa, and aspergillus nidulans. sixty percent of identical or similar amino acids were located in alpha/beta tim (triose-phosphate isomerase) barrels and in residues important in substrate binding and catalysis. in addition, the analy ...19902299982
expression in yeast of the t-urf13 protein from texas male-sterile maize mitochondria confers sensitivity to methomyl and to texas-cytoplasm-specific fungal toxins.the mitochondrial gene t-urf13 from maize (zea mays l.) with texas male-sterile (t) cytoplasm codes for a unique 13 kd polypeptide, t-urf13, which is implicated in cytoplasmic male sterility and sensitivity to the insecticide methomyl and to host-specific fungal toxins produced by helminthosporium maydis race t (hmt toxin) and phyllosticta maydis (pm toxin). a chimeric gene coding for t-urf13 fused to the mitochondrial targeting peptide from the neurospora crassa atp synthase subunit 9 precursor ...19902303028
the purification and characterization of 3-dehydroquinase from streptomyces coelicolor.the enzyme 3-dehydroquinase was purified over 4000-fold to homogeneity from streptomyces coelicolor. the subunit mr estimated from polyacrylamide-gel electrophoresis in the presence of sds was 16,000. the native mr estimated by gel filtration on a superose 6 column was 209,000, indicating that the enzyme is a large oligomer. the enzyme was found to be extremely thermostable. this stability, along with the structural and kinetic properties of the enzyme, suggest that it is very similar to the qui ...19902306211
dna sequence analysis of the mitochondrial nd4l-nd5 gene complex from podospora anserina. duplication of the nd4l gene within its intron.a 15 kb region of the 100 kb mitochondrial genome of podospora anserina has been mapped and sequenced (1 kb = 10(3) base-pairs). the genes for nd4l and nd5 are identified as contiguous genes with overlapping termination and initiation codons. in race a (101 kb) the gene for nd4l (4.3 kb) has a gene duplication within an intron including a second subgroup ic intron. race s (95 kb) lacks this second gene complex. each intron has the identical 5' exon boundary. secondary structure analysis showed t ...19902319602
blue light photoreception in neurospora circadian rhythm: evidence for involvement of the flavin triplet state.the mechanism of the photoreceptor acting on the circadian conidiation rhythm of neurospora crassa was studied, with the following results: (1) the efficiency of 8-haloflavins as sensitizers increased with their triplet yields. (2) phase shifts were not abolished by removal of oxygen prior to illumination. (3) oxygen inhibited phase shifts when introduced into the cultures after light treatment. it is proposed that the blue light photoreceptor for the circadian clock of neurospora crassa acts (1 ...19902367558
cloning and analysis of beta-tubulin gene from a protoctist.we have isolated and characterized by restriction endonuclease mapping, transcription pattern, and dna sequencing a beta-tubulin gene from the coenocytic freshwater protoctist, achlya klebsiana. the gene is intronless and has a single open reading frame that encodes a 444-amino acid residue polypeptide of mr 49,856. the protein shows a high degree of homology to other beta-tubulins, 85% identity to human beta-tubulin and 89% identity to beta-tubulin of the sporozoan (also a protoctist) plasmodiu ...19902394720
nuclear pre-mrna introns: analysis and comparison of intron sequences from tetrahymena thermophila and other eukaryotes.we have sequenced 14 introns from the ciliate tetrahymena thermophila and include these in an analysis of the 27 intron sequences available from seven t. thermophila protein-encoding genes. consensus 5' and 3' splice junctions were determined and found to resemble the junctions of other nuclear pre-mrna introns. unique features are noted and discussed. overall the introns have a mean a + t content of 85% (21% higher than neighbouring exons) with smaller introns tending towards a higher a + t con ...19902402440
growth and macromolecular synthesis phenotypes of a heat-sensitive mutant strain, rip-1, of neurospora crassa.a heat-sensitive mutant of neurospora crassa, strain 4m(t), was isolated using ultraviolet-light mutagenesis followed by the inositol-less death enrichment technique. the heat-sensitivity is the result of a single gene mutation which maps to the distal end of the right arm of linkage group ii. the mutation defines the rip-1 gene locus. both conidial germination and mycelial extension are inhibited in the mutant at 35 degrees c and above (the nonpermissive temperature) but prolonged incubation at ...19852412091
changes in gene expression elicited by amino acid limitation in neurospora crassa strains having normal or mutant cross-pathway amino acid control.the effects of amino acid limitation on gene expression have been investigated in neurospora crassa strains carrying normal (cpc-1+) or mutant (cpc-1) alleles at a locus implicated in cross-pathway amino acid control. electrophoresis and fluorography were used to reveal the patterns of label incorporation into polypeptides in vivo, or after in vitro translation of extracted mrnas. in a cpc-1+ strain at least 20% of detectable in vitro translation products showed relative increases in incorporati ...19852412092
rna splicing in neurospora mitochondria. defective splicing of mitochondrial mrna precursors in the nuclear mutant cyt18-1.cyt18-1 (299-9) is a nuclear mutant of neurospora crassa that has been shown to have a temperature-sensitive defect in splicing the mitochondrial large rrna intron. in the present work, we investigate the effect of the cyt18-1 mutation on splicing of mitochondrial mrna introns. two genes were studied in detail; the cytochrome b (cob) gene, which contains two introns, and a "long form" of the cytochrome oxidase subunit i (coi) gene, which contains four introns. we found that splicing of both cob ...19852413216
dna methylation at asymmetric sites is associated with numerous transition mutations.we describe two unusual 5s rna regions from neurospora crassa that are tightly linked. sequence analysis suggests that these genes or pseudogenes, which we designate zeta (zeta) and eta (eta), arose by a 794-base-pair tandem duplication followed by hundreds of exclusively cytosine to thymine mutations. the duplication was most likely generated by nonhomologous recombination involving a dna segment having a striking purine-pyrimidine strand asymmetry. restriction analysis of genomic dna from tiss ...19852415981
probing fungal mitochondrial evolution with trna.sequence data are now available for almost the entire complement of mitochondrial rrnas from five fungi: schizosaccharomyces pombe, saccharomyces cerevisiae, toropulis glabrata, aspergillus nidulans and neurospora crassa. analysis of these data show that the five mitochondria can be related to a common ancestor. the unusually high similarity between some s. pombe mt trnas may be due to a process similar to gene conversion. using the number of differences between trna pairs as a measure of the ev ...19852417640
simultaneous purification of three mitochondrial enzymes. acetylglutamate kinase, acetylglutamyl-phosphate reductase and carbamoyl-phosphate synthetase from neurospora crassa.the early enzymes of arginine biosynthesis in neurospora crassa are localized in the mitochondrion and catalyze the conversion of glutamate to citrulline. the final conversion of citrulline to arginine occurs via two enzymatic steps in the cytoplasm. we have devised a method for the isolation and purification of three of the mitochondrial arginine biosynthetic enzymes from a single extract. acetylglutamate kinase and acetylglutamyl-phosphate reductase (both products of the complex arg-6 locus) w ...19862420793
sequencing studies of icr-170 mutagenic specificity in the am (nadp-specific glutamate dehydrogenase) gene of neurospora crassa.the acridine half-mustard icr-170-induced reversion of the mutant am15, which has a single base-pair deletion, at a frequency of between 9 and 28 x 10(-6). in each of three classes of revertants, the mutagen had induced the insertion of a -g- -c- base pair at a -g-g- -c-c- site. the mutant am6, which has a single base pair insertion, is known to be revertible, with uv light, by deletion of a -g- -c- base pair at a -g-g-g- -c-c-c- site. this mutant reverted with icr-170 at a frequency of 0.1 x 10 ...19862423414
h+/atp stoichiometry of proton pumps from neurospora crassa and escherichia coli.a kinetic method has been used to measure the apparent stoichiometry of h+ ions translocated per atp split by membrane-bound [h+]-atpases. in this method, membrane vesicles are suspended in well-buffered medium, atp is added, and a fluorescent probe of delta ph (acridine orange) is used to detect the formation of a steady-state ph gradient. at the steady state, it is assumed that proton pumping in one direction is exactly balanced by the leak of protons in the opposite direction. the pump is the ...19862425739
immunological cross-reactivity of fungal and yeast plasma membrane h+-atpase.the plasma membrane h+-atpases from fungi and yeasts have similar catalytic and molecular properties. a structural comparison has been performed using immunoblot analysis with polyclonal antibodies directed toward the 102 kda polypeptide of the plasma membrane h+-atpase from neurospora crassa. a strong cross-reactivity is observed between the fungal h+-atpase and the enzyme from the yeasts saccharomyces cerevisiae and schizosaccharomyces pombe. structural homologies are indicated also by the ana ...19862428661
gamma-ray-sensitive mutants of neurospora crassa with characteristics analogous to ataxia telangiectasia cell lines.well characterized gamma-ray sensitive mutants of the fungus neurospora crassa have been screened for characteristics analogous to those of cell lines derived from humans with the genetic disease, ataxia telangiectasia (at). two neurospora mutants, uvs-6 and mus-9, show the at cell line characteristics of gamma-ray and bleomycin sensitivity, and little or no repression of dna synthesis following treatment with these agents. normal human or neurospora cells show an extensive biphasic dna synthesi ...19872434849
electron microscopy and image analysis of the mitochondrial outer membrane channel, vdac.the channel protein in the outer membrane of neurospora crassa mitochondria, vdac, forms extended planar crystals on the membrane. the arrays, which are induced by phospholipase a2, are polymorphic, varying from parallelogram (p) to near-rectangular (r) geometry with increased phospholipase treatment. computer-based analysis of projection images of negatively stained vdac arrays indicates that the protein forms a transmembrane channel in the p array. comparison of average images of arrays embedd ...19872442147
particular rna primer from growth medium differentially stimulates in vitro dna synthesis and in vivo cell growth of neurospora crassa and its slime mutant.purine rich small "rna-primer" molecules (about 10-12 nucleotides), secreted into the growth medium of 3-h germinated conidia of n. crassa, strongly stimulated a concentration-dependent in vitro dna synthesis of n. crassa slime mutant as well as dnas from the human cancer cells but did not affect that from normal cells. these "rna-primer" molecules stimulated also in vivo cell growth of n. crassa slime mutant, but not of the n. crassa wild type. our studies suggest that dnas from the slime mutan ...19872452704
a mutant of neurospora crassa deficient in cytochrome c heme lyase activity cannot import cytochrome c into mitochondria.the nuclear cyt-2-1 mutant of neurospora crassa is characterized by a gross deficiency of cytochrome c (bertrand, h., and collins, r. a. (1978) mol. gen. genet. 166, 1-13). the mutant produces mrna that can be translated into apocytochrome c in vitro. apocytochrome c is also synthesized in vivo in cyt-2-1, but it is rapidly degraded and thus does not accumulate in the cytosol. mitochondria from wild-type cells bind apocytochrome c made in vitro from either wild-type or cyt-2-1 mrna and convert i ...19882454235
purification of integral plasma membrane proteins by reverse-phase high performance liquid chromatography.following dissolution in anhydrous trifluoroacetic acid, plasma membrane isolated from two eukaryotic species was directly injected onto a reverse-phase high performance liquid chromatograph column. upon development with a 60 to 100% (v/v) linear gradient of ethanol containing 0.1% trifluoroacetic acid, most of the polypeptides eluted without retention. only the lipids and very hydrophobic proteins were retained and resolved. most noticeable among retained proteins was the mr 100,000 catalytic p ...19882454596
sensitivity to bleomycin and hydrogen peroxide of dna repair-defective mutants in neurospora crassa.mutations were induced in neurospora which cause increased sensitivity to mms (methyl methane-sulfonate) and other mutagens. genetic analysis of such mus demonstrated that some of them defined new dna repair genes (mus-21, and mus-27 to mus-30), while others represented new alleles in previously known genes. to characterize them further, and especially to identify rec- types which have not yet been found in this species, many mms-sensitive strains were tested for cross-sensitivities to bleomycin ...19892463486
inhibition by aluminum hydroxide of the voltage-dependent closure of the mitochondrial channel, vdac.micromolar quantities of aluminum have been found (dill et al. (1987) j. membrane biol. 99, 187-196) to reduce the voltage dependence of the mitochondrial outer membrane channel, vdac, from neurospora crassa. in the present study, various metallic and organic ions were tested for possible aluminum-like effect, and only the trivalent metals exhibited a similar ability to reduce the channels voltage dependence. however, trivalency alone was not sufficient because lanthanum (iii) had no effect. qua ...19892469483
fusion of the mitochondrial outer membrane: use in forming large, two-dimensional crystals of the voltage-dependent, anion-selective channel protein.phospholipase a2 induces crystallization of the channel protein, vdac (also called mitochondrial porin), in the outer membrane of neurospora crassa mitochondria. the channel crystals formed in native membranes typically contain a few hundred unit cells. to increase the size of these membrane crystals for low-contrast electron microscopic imaging and diffraction studies, fusion of the isolated mitochondrial outer membranes was attempted before and after phospholipase treatment. successful fusion ...19892470408
pneumocystis carinii: sequence from ribosomal rna implies a close relationship with fungi.pneumocystis carinii is the etiologic agent of a lethal pneumonia which occurs in patients with the acquired immune deficiency syndrome (aids) and other immunocompromised hosts. the basic biochemical and genetic characteristics of p. carinii are poorly understood and its taxonomic classification as a protozoan is uncertain. to address the taxonomic question, a method was developed for the extraction of total rna from p. carinii. denaturing agarose gel electrophoresis showed the two ribosomal rna ...19892470612
pneumocystis carinii: taxing taxonomy.the detailed taxonomy of pneumocystis carinii has not been decided. most experts agree that it is either a fungus or a protozoan. in favor of a fungal designation are the recent reports that 16s and 18s rrna sequences of p. carinii have greater homology to saccharomyces cerevisiae and neurospora crassa than to selected protozoa. other studies show that sequences of the 18s and 26s rrna, microtubular ultrastructure, membrane fusion potential and dna content per cell resemble protozoa more than fu ...19892477272
mutations in nuclear gene cyt-4 of neurospora crassa result in pleiotropic defects in processing and splicing of mitochondrial rnas.the nuclear cyt-4 mutants of neurospora crassa have been shown previously to be defective in splicing the group i intron in the mitochondrial large rrna gene and in 3' end synthesis of the mitochondrial large rrna. here, northern hybridization experiments show that the cyt-4-1 mutant has alterations in a number of mitochondrial rna processing pathways, including those for cob, coi, coii and atpase 6 mrnas, as well as mitochondrial trnas. defects in these pathways include inhibition of 5' and 3' ...19892478417
characterization of the mitochondrial porin from drosophila melanogaster.mitochondrial porin was isolated from the fruit fly drosophila melanogaster at different developmental stages, starting from whole mitochondria. the porin from adults' mitochondria was fully characterized. the protein had a molecular mass of 31 kda as judged from sodium dodecylsulfate electrophoretograms. it was very resistive against digestion with v8 proteinase of staphylococcus aureus and a larger number of fragments were only obtained after digestion with papain. drosophila porin showed litt ...19892480813
dna sequence and secondary structures of the large subunit rrna coding regions and its two class i introns of mitochondrial dna from podospora anserina.dna sequence analysis has shown that the gene coding for the mitochondrial (mt) large subunit ribosomal rna (rrna) from podospora anserina is interrupted by two class i introns. the coding region for the large subunit rrna itself is 3715 bp and the two introns are 1544 (r1) and 2404 (r2) bp in length. secondary structure models for the large subunit rrna were constructed and compared with the equivalent structure from escherichia coli 23s rrna. the two structures were remarkably similar despite ...19892494353
genetic transformation system for the aflatoxin-producing fungus aspergillus flavus.a heterologous transformation system was developed for aspergillus flavus with efficiencies greater than 20 stable transformants per micrograms of dna. protoplasts of uracil-requiring strains of the fungus were transformed with plasmid and cosmid vectors containing the pyr-4 gene of neurospora crassa. transformants were selected for their ability to grow and sporulate on medium lacking uracil. vector dna appeared to integrate randomly into the genome of a. flavus with a tendency for multiple, ta ...19892495764
[properties of 2,5-diamino-4-oxy-6-ribosylaminopyrimidine-5'- phosphate reductase, a enzyme of the second stage of flavinogenesis in pichia guilliermondii yeasts].2,5-diamino-4-oxy-6-ribosylaminopyrimidine-5'-phosphate reductase has been isolated from cells of pichia guilliermondii and subjected to 20-fold purification by treating extracts with streptomycin sulphate, frationating proteins (nh4)2so4 at 45-75% of saturation and chromatography on blue sepharose cl-6b. the use of gel filtration through sephadex g-150 and chromatography on deae-cellulose proved to be less effective for the enzyme purification. it has been established that it is 2,5-diamino-4-o ...19892511652
a mitochondrial protein from neurospora crassa detected both on ribosomes and in membrane fractions. analysis of the gene, the message, and the protein.we have isolated clones representing at least three nuclear genes for mitochondrial ribosomal proteins from neurospora crassa by screening a lambda gt11 cdna library with an antiserum against a mixture of these proteins. the cdna and genomic dna sequence for one of these genes, mrp-3, was determined. the mrp3 protein was purified by immune-affinity chromatography, using a monoclonal antibody probe, and subjected to amino acid sequence analysis to identify the mature amino terminus and a prospect ...19892521217
nad-specific glutamate dehydrogenase of neurospora crassa. cdna cloning and gene expression during derepression.the catabolic nad-specific glutamate dehydrogenase of neurospora crassa is one of the many enzymes regulated by carbon catabolite repression. to achieve an understanding of its regulation, cdna and genomic clones were isolated. total poly(a+) rna from derepressed cells was used for the construction of a cdna library in the expression vector, lambda gt11. by screening this library with a polyclonal antiserum against nad-specific glutamate dehydrogenase, a positive clone with a 0.9-kilobase insert ...19892521336
x-ray-induced specific-locus mutations in the ad-3 region of two-component heterokaryons of neurospora crassa. ii. more extensive genetic tests reveal an unexpectedly high frequency of multiple-locus mutations.more extensive genetic tests have been performed on a series of 832 x-ray-induced specific-locus mutations in the ad-3 region of a 2-component heterokaryon (h-12) of neurospora crassa, reported earlier (webber and de serres 1965). using new tester strains and techniques for performing large-scale genetic tests (heterokaryon, dikaryon and trikaryon) to characterize ad-3 mutants induced in 2-component heterokaryons, new data have been obtained on this sample of x-ray-induced ad-3 mutants. these ne ...19892521371
genes expressed during conidiation in neurospora crassa: characterization of con-8.the filamentous fungus neurospora crassa, by a series of defined changes, differentiates from a mycelium composed of branching hyphae to form dormant spores, called conidia. several genes of unknown function (con genes) that are preferentially expressed during this period have been cloned. transcription of these genes has been examined in conidiation-defective mutants, and the results obtained revealed that con-6, con-8, con-10, con-11 and con-13 are most likely to play a unique role during coni ...19892521382
sedimentation properties of chitosomal chitin synthetase from the wild-type strain and the 'slime' variant of neurospora crassa.marked differences in the pattern of sedimentation of cellular structures were observed after isopycnic centrifugation of crude cell-free preparations from the neurospora crassa wall-less 'slime' variant and mycelial wild-type strain. kinetic studies of particle sedimentation showed that the various types of subcellular components, as revealed by turbidity, uv absorption, polypeptide patterns, and chitin synthetase activity determinations, sediment independently of one another. an important feat ...19892521563
neurospora crassa alpha-ketoglutarate dehydrogenase complex: description, resolution of components and catalytic properties.a method is proposed for the purification of the neurospora crassa alpha-ketoglutarate dehydrogenase complex, and the main points for preserving its activity, which seems to be particularly fragile in fungus, are discussed. resolution of the constitutive enzymes was attempted and permitted the identification of the three protein bands resolved on sds-polyacrylamide gel electrophoresis as e3, e1 and e2 with respective mr values of 54,000, 53,000 and 49,000. catalytic properties of the purified co ...19892521564
deoxyglucose-resistant mutants of neurospora crassa: isolation, mapping, and biochemical characterization.neurospora crassa mutants resistant to 2-deoxyglucose have been isolated, and their mutations have been mapped to four genetic loci. the mutants have the following characteristics: (i) they are resistant to sorbose as well as to 2-deoxyglucose; (ii) they are partially or completely constitutive for glucose transport system ii, glucamylase, and invertase, which are usually repressed during growth on glucose; and (iii) they synthesize an invertase with abnormal thermostability and immunological pr ...19892521617
nucleotide sequence of the neurospora crassa trp-3 gene encoding tryptophan synthetase and comparison of the trp-3 polypeptide with its homologs in saccharomyces cerevisiae and escherichia coli.the complete nucleotide sequence of the neurospora crassa trp-3 gene-encoding tryptophan synthetase has been determined; we present an analysis of its structure. a comparison of the deduced amino acid sequence of the trp-3 polypeptide with its homologs in saccharomyces cerevisiae (encoded by the trp5 gene) and escherichia coli (encoded by the trpa and trpb genes) shows that the a and b domains (amino acid segments homologous to the trpa and trpb polypeptides, respectively) of the n. crassa and y ...19892521855
in vivo control of gluconeogenesis in wild-type neurospora crassa and in the adenylate cyclase-deficient cr-1 (crisp) mutant.the rate of cycloheximide-resistant incorporation of carbon from [14c]alanine and [14c]acetate into polysaccharidic material was used to study gluconeogenic activity in wild-type neurospora crassa and in the adenylate cyclase-deficient cr-1 (crisp-1) mutant. the wild-type efficiently utilized alanine and acetate as gluconeogenic substrates, whereas the mutant used acetate efficiently but was unable to use alanine. cycloheximide-resistant 14c-incorporating activity was sensitive to carbon catabol ...19892522093
13n isotope studies of glutamine assimilation pathways in neurospora crassa.l-[amide-13n]glutamine in neurospora crassa is metabolized to [13n]glutamate by glutamate synthase and to [13n]ammonium by the glutamine transaminase-omega-amidase pathway. the [13n]ammonium released is assimilated by glutamate dehydrogenase and glutamine synthetase, confirming the operation of a glutamine cycle. most of the nitrogen is retained during cycling between glutamate and glutamine.19892522094
molybdenum cofactor biosynthesis in humans. identification of two complementation groups of cofactor-deficient patients and preliminary characterization of a diffusible molybdopterin precursor.molybdenum cofactor deficiency is a devastating disease with affected patients displaying the symptoms of a combined deficiency of sulfite oxidase and xanthine dehydrogenase. because of the extreme lability of the isolated, functional molybdenum cofactor, direct cofactor replacement therapy is not feasible, and a search for stable biosynthetic intermediates was undertaken. from studies of cocultured fibroblasts from affected individuals, two complementation groups were identified. coculture of g ...19892522104
x-ray-induced specific locus mutations in the ad-3 region of two-component heterokaryons of neurospora crassa. iii. genetic fine structure analysis of the ad-3 and immediately adjacent genetic regions by means of complementation tests.genetic fine structure analysis of the ad-3 and immediately adjacent genetic regions was made by means of complementation tests on all possible pairwise combinations of 50 x-ray-induced irreparable adenine-3 mutants (designated ad-3ir). all mutants were induced in either heterokaryon 11 or heterokaryon 12 of neurospora crassa, 2-component heterokaryons heterozygous for mutants at the 3 closely linked loci ad-3a and ad-3b and nic-2 (nicotinamide-requiring) located about 5.0 map units distal to ad ...19892522164
a small isoform of nadh:ubiquinone oxidoreductase (complex i) without mitochondrially encoded subunits is made in chloramphenicol-treated neurospora crassa.in mitochondria of neurospora crassa grown in the presence of chloramphenicol a small form of nadh:ubiquinone reductase is made in place of the normal electron-transfer-complex i. this smaller enzyme has a molecular mass of approximately 350 kda and consists of (at least) 13 different subunits which are all synthesized in the cytoplasm. the complex i which is normally found in neurospora has a molecular mass of approximately 700 kda and consists of around 30 different subunits, of which at least ...19892523306
identification of an arginine carrier in the vacuolar membrane of neurospora crassa.a number of arginine derivatives were tested for their ability to inhibit arginine uptake into vacuolar membrane vesicles of neurospora crassa. the guanido side chain and l-configuration were found to be important for recognition by the arginine carrier. based upon the specificity of recognition, a reactive arginine derivative (n alpha-p-nitrobenzyloxycarbonyl arginyl diazomethane) was synthesized which has an intact guanido side chain and a diazo group at the carboxyl end. the latter decomposes ...19892523392
assembly kinetics and identification of precursor proteins of complex i from neurospora crassa.complex i from neurospora crassa was fractionated using chaotropic agents and various chromatographic techniques. several subunits were isolated. polyclonal antibodies directed against the holocomplex or individual subunits were raised in rabbits, and employed to analyse the composition and assembly of this respiratory chain enzyme in vivo. n. crassa cells were pulse-labelled with radioactive amino acids. the time course of incorporation of radioactivity into complex-i polypeptides was studied b ...19892523803
a family of mitochondrial proteins involved in bioenergetics and biogenesis.the respiratory chain complexes of mitochondria consist of many different subunits, of which only a few partake directly in electron transport. the functions of the subunits that do not contain prosthetic groups are largely unknown. the cytochrome reductase complex of neurospora crassa, for examine, consists of nine different subunits, of which the peripheral membrane proteins i and ii (ref.3) that are located on the matrix side of the mitochondrial inner membrane are the largest subunits devoid ...19892524007
purification and characterisation of nad-glutamate dehydrogenase from aspergillus nidulans.nad-glutamate dehydrogenase has been purified from mycelia of a. nidulans. the enzyme comprises subunits of 110 kda. it is located in the cytosol. it is completely denatured by 1.0 m guanidine hydrochloride, and is not renatured by subsequent dilution. isophthalate is a strong competitive inhibitor and the enzyme is also inhibited by thiol reagents. the properties of the enzyme were compared to those from other fungi in terms of size, sensitivity to inhibitors, intracellular distribution and mod ...19892524418
change in chromosome number associated with a double deletion in the neurospora crassa mitochondrial chromosome.the mitochondrial genome of neurospora is usually found in a single covalently closed circular 62-kbp dna molecule. we report here that the mitochondrial genome of a phenotypic revertant of a stopper mutant (stp-ruv) is contained primarily in two separate, nonoverlapping, autonomously replicating circular chromosomes. the circles, one about 21 kbp and the other somewhat less than 36 kbp are derived from the most frequent classes of recombinant chromosomes (21 and 41 kbp) in the chromosomal popul ...19892524420
recombination and replication of plasmid-like derivatives of a short section of the mitochondrial chromosome of neurospora crassa.the 21-kbp mitochondrial chromosome of the stp-ruv strain of neurospora crassa undergoes regional amplification yielding plasmid-like supercoiled circles varying in size from subunit length to very high multimers. a comparison of the base sequence of the five plasmids studied, with the region of the chromosome from which they were derived, indicated that the amplified chromosomal segments were determined by a recombination-excision process near or within two structurally distinctive regions. one ...19892524421
a morphological and genetic analysis of conidiophore development in neurospora crassa.the filamentous fungus neurospora crassa responds to nutrient deprivation and dessication by producing asexual spores, or conidia. these conidia are derived from differentiated aerial structures called conidiophores. the process of conidiation was analyzed in wild-type and morphological mutants using scanning electron microscopy (sem) and specific fluorescent probes. the first discernible morphological step of conidiation is the transition from growth by hyphal tip elongation to growth by repeat ...19892524423
cys-3, the positive-acting sulfur regulatory gene of neurospora crassa, encodes a protein with a putative leucine zipper dna-binding element.the sulfur-regulatory circuit of neurospora crassa consists of a set of unlinked structural genes which encode sulfur-catabolic enzymes and two major regulatory genes which govern their expression. the positive-acting cys-3 regulatory gene is required to turn on the expression of the sulfur-related enzymes, whereas the other regulatory gene, scon, acts in a negative fashion to repress the synthesis of the same set of enzymes. expression of the cys-3 regulatory gene was found to be controlled by ...19892524646
molecular cloning of a neurospora crassa carotenoid biosynthetic gene (albino-3) regulated by blue light and the products of the white collar genes.the albino-3 (al-3) gene of neurospora crassa, which probably encodes the carotenoid biosynthetic enzyme geranylgeranyl pyrophosphate synthetase, was cloned. the n. crassa triple mutant al-3 qa-2 aro-9 was transformed to qa-2+ with mixtures of plasmids bearing n. crassa dna inserts, and the transformants were screened for the al-3+ phenotype. one al-3+ qa-2+ transformant (al3-1) was examined in detail and shown to contain intact vector sequences integrated into the n. crassa genome. the vector a ...19892524647
immunological identification of the alternative oxidase of neurospora crassa mitochondria.neurospora crassa mitochondria use a branched electron transport system in which one branch is a conventional cytochrome system and the other is an alternative cyanide-resistant, hydroxamic acid-sensitive oxidase that is induced when the cytochrome system is impaired. we used a monoclonal antibody to the alternative oxidase of the higher plant sauromatum guttatum to identify a similar set of related polypeptides (mr, 36,500 and 37,000) that was associated with the alternative oxidase activity of ...19892524649
independent transfer of mitochondrial plasmids in neurospora crassa.in the ascomycete fungus neurospora, the distribution of homologous mitochondrial plasmid dnas in different species and among mitochondrial types of n. crassa suggests that these molecules have moved between lineages of clonally propagated mtdna. here we report direct evidence for independent inheritance of mitochondrial plasmids by sexual reproduction which may help explain the distribution of these molecules among mitochondrial lineages.19892524667
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