Publications

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the mig1 repressor from kluyveromyces lactis: cloning, sequencing and functional analysis in saccharomyces cerevisiae.sequence comparisons between saccharomyces cerevisiae scmig1 and aspergillus nidulans crea proteins allowed us to design two sets of degenerate primers from the conserved zinc finger loops. pcr amplification on kluyveromyces marxianus and k. lactis genomic dna yielded single products with sequences closely related to each other and to the corresponding regions of scmig1 and crea. the kimig1 gene of k. lactis was cloned from a genomic library using the k. marxianus pcr fragment as probe. kimig1 e ...19957672126
molecular characterization of a gene encoding a homogentisate dioxygenase from aspergillus nidulans and identification of its human and plant homologues.we report here the first characterization of a gene encoding a homogentisate dioxygenase, the aspergillus nidulans hmga gene. the hmga protein catalyzes an essential step in phenylalanine catabolism, and disruption of the gene results in accumulation of homogentisate in broths containing phenylalanine. hmga putatively encodes a 448-residue polypeptide (mr = 50,168) containing 21 histidine and 23 tyrosine residues. this polypeptide has been expressed in escherichia coli as a fusion to glutathione ...19957673153
use of reporter genes to identify recessive trans-acting mutations specifically involved in the regulation of aspergillus nidulans penicillin biosynthesis genes.starting from three amino acid precursors, penicillin biosynthesis is catalyzed by three enzymes which are encoded by the following three genes: acva (pcbab), ipna (pcbc), and aat (pende). to identify trans-acting mutations which are specifically involved in the regulation of these secondary metabolism genes, a molecular approach was employed by using an aspergillus nidulans strain (axtii9) carrying acva-uida and ipna-lacz gene fusions integrated in double copies at the chromosomal argb gene. on ...19957677843
aspergillus nidulans apsa (anucleate primary sterigmata) encodes a coiled-coil protein required for nuclear positioning and completion of asexual development.many fungi are capable of growing by polarized cellular extension to form hyphae or by isotropic expansion to form buds. aspergillus nidulans anucleate primary sterigmata (apsa) mutants are defective in nuclear distribution in both hyphae and in specialized, multicellular reproductive structures, called conidiophores. apsa mutations have a negligible effect on hyphal growth, unlike another class of nuclear distribution (nud) mutants. by contrast, they almost completely block entry of nuclei into ...19957860626
myoa of aspergillus nidulans encodes an essential myosin i required for secretion and polarized growth.we have identified and cloned a novel essential myosin i in aspergillus nidulans called myoa. the 1,249-amino acid predicted polypeptide encoded by myoa is most similar to the amoeboid myosins i. using affinity-purified antibodies against the unique myosin i carboxyl terminus, we have determined that myoa is enriched at growing hyphal tips. disruption of myoa by homologous recombination resulted in a diploid strain heterozygous for the myoa gene disruption. we can recover haploids with an intact ...19957860631
molecular similarity matrices and quantitative structure-activity relationships: a case study with methodological implications.recently, statistical analysis of molecular similarity matrices has been applied to the quantitative structure-activity relationship (qsar) analysis of a number of molecular series. this paper addresses a number of methodological issues relative to the similarity matrices. a series of halogenated aliphatic hydrocarbons, for which the mutation (aneuploidy) induction ability had previously been determined, was used as test bench. the chemical information carried by the similarity matrices was show ...19957861411
gene inactivation in the plant pathogen glomerella cingulata: three strategies for the disruption of the pectin lyase gene pnla.the feasibility of performing routine transformation-mediated mutagenesis in glomerella cingulata was analysed by adopting three one-step gene disruption strategies targeted at the pectin lyase gene pnla. the efficiencies of disruption following transformation with gene replacement- or gene truncation-disruption vectors were compared. to effect replacement-disruption, g. cingulata was transformed with a vector carrying dna from the pnla locus in which the majority of the coding sequence had been ...19957862090
yeast proteins can activate expression through regulatory sequences of the amds gene of aspergillus nidulans.the upstream regulatory region of the amds gene of aspergillus nidulans contains a ccaat sequence known to be important in setting both basal and depressed levels of expression. we have investigated whether the ccaat-binding hap2/3/4 complex of the yeast saccharomyces cerevisiae can recognise this sequence in an amds context. sequences from the 5' region of amds were cloned in front of the cyc1-lacz fusion gene bearing a minimal promoter and transformed into wild-type and hap2 strains of yeast. ...19957862093
the genetics of nuclear migration in fungi. 19957779511
a heuristic approach to the analysis of enzymic catalysis: reaction of delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-alpha-aminobutyrate and delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-allylglycine catalyzed by isopenicillin n synthase isozymes.isopenicillin n synthase (ipns) catalyzes the oxidative cyclization of delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine to isopenicillin n. it is proposed that the multiple products produced from certain substrate analogues result from pathway branching after formation of a ferryl oxene intermediate. we have been interested in ascertaining the reasons for multiple product formation. one possibility is that the products are predisposed toward formation once the beta-lactam ring and the ferryl ox ...19957779800
sequence analysis of the aspergillus nidulans pectate lyase pela gene and evidence for binding of promoter regions to crea, a regulator of carbon catabolite repression.the nucleic acid and deduced amino-acid sequences of the pectate lyase gene (pela) from aspergillus nidulans are presented. the pela gene contains two short introns, 68 and 49 bp in length, and encodes a peptide of 326 amino acids. five transcriptional start sites are clustered between 65 and 79 bp upstream of the start codon as determined by primer extension. comparison of the amino-acid sequences of pectate or pectin lyases from bacteria, fungi and plants revealed less than 30% overall identit ...19957788717
molecular cloning and analysis of nre, the major nitrogen regulatory gene of penicillium chrysogenum.we have isolated the penicillium chrysogenum nre gene which is homologous to the major nitrogen regulatory genes area from aspergillus nidulans and nit-2 from neurospora crassa. overall, nre shows 60% identity to area and 30% identity to nit-2 at the amino-acid level. the gene encodes a protein of 835 amino-acid residues and contains a single cys2/cys2-type zinc finger with an adjacent basic region and a putative acidic activation region. in the dna-binding domain, 98% of the amino-acid residues ...19957788718
a mini-promoter lacz gene fusion for the analysis of fungal transcription control sequences.a system for the in vivo analysis of fungal transcription control sequences, based on a mini-promoter, was designed. the mini-promoter, providing all sequences necessary and sufficient for transcription initiation, was derived from the aspergillus nidulans gpda promoter region. transcription initiation was not affected by the introduction of transcription control sequences directly upstream from the mini-promoter. furthermore, the expression of the mini-promoter was not affected by wide-domain c ...19957789794
a mutualistic fungal symbiont of perennial ryegrass contains two different pyr4 genes, both expressing orotidine-5'-monophosphate decarboxylase.a fragment of the claviceps purpurea pyr4 gene, encoding orotidine-5'-monophosphate decarboxylase (omp decarboxylase), was used to screen a genomic library from an isolate of a fungus, acremonium sp. (designated lp1), which grows as an endophyte in perennial ryegrass (lolium perenne). three positive clones, lambda mc11, lambda mc12 and lambda mc14, were isolated. two of these clones, lambda mc12 and lambda mc14, were overlapping clones from the same locus, while lambda mc11 was from a different ...19957789808
crystal structure of isopenicillin n synthase is the first from a new structural family of enzymes.penicillin antibiotics are all produced from fermentation-derived penicillins because their chemical synthesis is not commercially viable. the key step in penicillin biosynthesis, in which both the beta-lactam and thiazolidine rings of the nucleus are created, is mediated by isopenicillin n synthase (ipns), which binds ferrous iron and uses dioxygen as a cosubstrate. in a unique enzymatic step, with no chemical precedent, ipns catalyses the transfer of four hydrogen atoms from its tripeptide sub ...19957791906
evidence for a nima-like mitotic pathway in vertebrate cells.nima is essential for entry into mitosis in aspergillus nidulans. to examine whether there is a nima-like pathway in other eukaryotic cell cycles, we expressed nima and its dominant negative mutants in two different eukaryotic systems. in xenopus oocytes, nima induced germinal vesicle breakdown without activating mos, cdc2, or map kinase. in hela cells, nima induced premature mitotic events without activating cdc2, whereas the mutants caused a specific g2 arrest but did not block mutant cdc2t14a ...19957736593
development of primer sets designed for use with the pcr to amplify conserved genes from filamentous ascomycetes.we constructed nine sets of oligonucleotide primers on the basis of the results of dna hybridization of cloned genes from neurospora crassa and aspergillus nidulans to the genomes of select filamentous ascomycetes and deuteromycetes (with filamentous ascomycete affiliations). nine sets of primers were designed to amplify segments of dna that span one or more introns in conserved genes. pcr dna amplification with the nine primer sets with genomic dna from ascomycetes, deuteromycetes, basidiomycet ...19957747954
purification and characterization of assembly-competent tubulin from aspergillus nidulans.we have developed a procedure for purifying assembly-competent tubulin from aspergillus nidulans. to our knowledge, this is the first report of the purification of assembly-competent tubulin from a filamentous fungus, and the procedure should be of great value in analyzing the large number of alpha- and beta-tubulin mutations that have been isolated and characterized in a. nidulans. our procedure consists of overproduction of alpha- and beta-tubulin, partial purification by ion-exchange chromato ...19957756266
substrate specificity and cell cycle regulation of the nek2 protein kinase, a potential human homolog of the mitotic regulator nima of aspergillus nidulans.the human nek2 protein kinase is the closest known mammalian relative of the mitotic regulator nima of aspergillus nidulans. the two kinases share 47% sequence identity over their catalytic domains and display a similar cell cycle-dependent expression peaking at the g2 to m phase transition. hence, it is attractive to speculate that human nek2 and fungal nima may carry out similar functions at the onset of mitosis. to study the biochemical properties and substrate specificity of human nek2 and c ...19957759549
antifungal effects of allium sativum (garlic) extract against the aspergillus species involved in otomycosis.otomycosis due to saprophytic keratolytic fungi represents a small percentage of clinical external otitis. although there are certain antibacterial and antifungal agents available, they usually are very caustic, potentially ototoxic and cannot be used if the ear drum is perforated. garlic is utilized as a folk medicine in many countries for its antimicrobial and other beneficial properties. in response to a lack of otic preparations, the authors studied the efficacy of garlic extracts against th ...19957765862
purification of a heat-stable chitin deacetylase from aspergillus nidulans and its role in cell wall degradation.an extracellular chitin deacetylase activity has been purified to homogeneity from autolyzed cultures of aspergillus nidulans. this enzyme is an acidic glycoprotein with a pi of 2.75 and a 28% (wt/wt) carbohydrate content. the apparent m(r) of the enzyme estimated by sds/page and superose 12 (f.p.l.c.) was around 27,000. the enzyme had an optimum ph at 7.0 and was stable in the ph range 4.0-7.5. its optimum temperature of reaction was 50 degrees c, and it was stable from 30 degrees to 100 degree ...19957765883
extragenic suppressors of a dynein mutation that blocks nuclear migration in aspergillus nidulans.cytoplasmic dynein is a large molecular weight protein complex that functions as a microtubule-dependent, negative, end-directed "motor." mutations in nuda, which encodes the heavy chain of cytoplasmic dynein, inhibit nuclear migration in aspergillus nidulans. this paper describes the selection and characterization of extragenic suppressors of the nuda1 mutation preparatory to the identification of other proteins that interact directly or indirectly with the cytoplasmic dynein heavy chain. to fa ...19957768435
polarity of meiotic gene conversion is 5' to 3' within the niad gene of aspergillus nidulans.we have examined polarity of meiotic gene conversion in the niia-niad gene cluster of aspergillus nidulans in two-point crosses. the type and position of the mutations represented by the niad alleles and the correlation between the relative frequency of gene conversion and the physical position of these mutations were determined. we show that polarity of meiotic gene conversion is 5' to 3' (transcribed strand) within the niad gene. additional crosses involving a niia allele and a niad allele sho ...19957770039
isolation and characterisation of genes for sulphate activation and reduction in aspergillus nidulans: implications for evolution of an allosteric control region by gene duplication.a region of the aspergillus nidulans genome carrying the sa and sc genes, encoding paps reductase and atp sulphurylase, respectively, was isolated by transformation of an sa mutant with a cosmid library. the genes were subcloned and their functions confirmed by retransformation and complementation of a. nidulans strains carrying sa and sc mutations. the physical distance of 2 kb between the genes corresponds to a genetic distance of 1 cm. while the deduced amino acid sequence of the sa gene prod ...19957770049
genes for beta-lactam antibiotic biosynthesis.the genes pcbab, pcbc and pende encoding enzymes involved in the biosynthesis of penicillin have been cloned from penicillium chrysogenum and aspergillus nidulans. they are clustered in chromosome i (10.4 mb) of p. chrysogenum, but they are located in chromosome ii of penicillium notatum (9.6 mb) and in chromosome vi (3.0 mb) of a. nidulans. expression studies have shown that each gene is expressed as a single transcript from separate promoters. enzyme regulation studies and gene expression anal ...19957771766
characterization of a prolactin-inducible gene, clone 15, in t cells.to examine how prl regulates lymphocyte proliferation, a number of prl-activated genes were identified from a prl-dependent rat t lymphoma cell line, nb2. one of the downstream genes in the prl signaling cascade was identified as clone 15 (c15). prl stimulation of quiescent nb2 t cells results in the expression of a 1.7-kilobase c15 mrna, which reaches maximum levels between 8 and 10 h after stimulation. corresponding [3h]thymidine incorporation experiments show that the maximum level of c15 mrn ...19957776977
the aspergillus pacc zinc finger transcription factor mediates regulation of both acid- and alkaline-expressed genes by ambient ph.the ph regulation of gene expression in aspergillus nidulans is mediated by pacc, whose 678 residue-derived protein contains three putative cys2his2 zinc fingers. ten paccc mutations mimicking growth at alkaline ph remove between 100 and 214 c-terminal residues, including a highly acidic region containing an acidic glutamine repeat. nine pacc+/- mutations mimicking acidic growth conditions remove between 299 and 505 c-terminal residues. deletion of the entire pacc coding region mimics acidity bu ...19957882981
flbd encodes a myb-like dna-binding protein that coordinates initiation of aspergillus nidulans conidiophore development.the timing of asexual fruiting body formation during aspergillus nidulans colony development is precisely regulated so that conidiophores are typically produced 1-2 mm behind the growing edge of the colony. mutations in any of four a. nidulans genes, flbb, flbc, flbd, or flbe, result in colonies that are delayed at least 24 hr in their ability to initiate conidiophore development resulting in fluffy colonies with conidiophores forming in the center, at least 12-15 mm behind the growing edge. the ...19957883170
amino acid transporters of lower eukaryotes: regulation, structure and topogenesis.lower eukaryotes such as the yeast saccharomyces cerevisiae and the filamentous fungus aspergillus nidulans possess a multiplicity of amino acid transporters or permeases which exhibit different properties with respect to substrate affinity, specificity, capacity and regulation. regulation of amino acid uptake in response to physiological conditions of growth is achieved principally by a dual mechanism; control of gene expression, mediated by a complex interplay of pathway-specific and wide-doma ...19957888172
the nima protein kinase is hyperphosphorylated and activated downstream of p34cdc2/cyclin b: coordination of two mitosis promoting kinases.initiation of mitosis in aspergillus nidulans requires activation of two protein kinases, p34cdc2/cyclin b and nima. forced expression of nima, even when p34cdc2 was inactivated, promoted chromatin condensation. nima may therefore directly cause mitotic chromosome condensation. however, the mitosis-promoting function of nima is normally under control of p34cdc2/cyclin b as the active g2 form of nima is hyperphosphorylated and further activated by p34cdc2/cyclin b when cells initiate mitosis. to ...19957889944
mitotic destruction of the cell cycle regulated nima protein kinase of aspergillus nidulans is required for mitotic exit.nima is a cell cycle regulated protein kinase required, in addition to p34cdc2/cyclin b, for initiation of mitosis in aspergillus nidulans. like cyclin b, nima accumulates when cells are arrested in g2 and is degraded as cells traverse mitosis. however, it is stable in cells arrested in mitosis. nima, and related kinases, have an n-terminal kinase domain and a c-terminal extension. deletion of the c-terminus does not completely inactivate nima kinase activity but does prevent functional compleme ...19957889945
starvation stress modulates the expression of the aspergillus nidulans brla regulatory gene.expression of the aspergillus nidulans brla gene plays a fundamental role in the switch from vegetative growth to asexual reproduction. using a media-shifting protocol to induce submerged sporulation and brla-lacz as an expression marker, it was shown that carbon and nitrogen starvation stress induced brla transcription to different degrees. glucose starvation induced bria rapidly to high levels and resulted in spore formation on reduced conidiophores, whereas nitrogen starvation induced brla gr ...19957894714
carbon regulation of penicillin biosynthesis in aspergillus nidulans: a minor effect of mutations in creb and crec.transcription of the aspergillus nidulans ipna gene is under carbon regulation. loss-of-function mutations in creb or crec do not cause full derepression of ipna transcript levels in sucrose-grown mycelia and do not elevate repressed penicillin levels, indicating that neither of these genes plays a major regulatory role in penicillin biosynthesis. however, these mutations reduce external ph acidification, accelerate sucrose degradation and result in extracellular accumulation of resulting d-gluc ...19957896078
site-directed mutagenesis of nitrate reductase from aspergillus nidulans. identification of some essential and some nonessential amino acids among conserved residues.nitrate reductase is a multiredox enzyme possessing three functional domains associated with the prosthetic groups fad, heme iron, and molybdopterin. in aspergillus nidulans, it is encoded by the niad gene. a homologous transformation system has been used whereby a major deletion at the niianiad locus of the host was repaired by gene replacement. employing site-directed mutagenesis and this transformation system, nine niad mutants were generated carrying specific amino acid substitutions. mutant ...19957896804
the use of electrospray mass spectrometry to identify an essential arginine residue in type ii dehydroquinases.the arginine-specific reagent phenylglyoxal has been used to identify a hyper-reactive arginine residue which is essential for activity in the type ii dehydroquinases of streptomyces coelicolor and aspergillus nidulans. electrospray mass spectrometry was used both to characterise the phenylglyoxal modified protein, and to identify the phenylglyoxal modified peptides following enzymatic digestion. the advantages of using electrospray mass spectrometry for monitoring arginine modication aimed at i ...19957875309
transformation of aspergillus nidulans by microprojectile bombardment on intact conidia.this paper describes transformation of intact conidia of aspergillus nidulans, auxotrophic for arginine, by using the biolistic process. the plasmid employed was pfb39, carrying the argb gene. the transformation frequency obtained was 81 transformants/microgram of dna. classical genetics and molecular analysis were conducted to analyse transformants and to determine in which chromosome integration took place.19957875577
cloning and molecular characterization of hxa, the gene coding for the xanthine dehydrogenase (purine hydroxylase i) of aspergillus nidulans.we have cloned and sequenced the hxa gene coding for the xanthine dehydrogenase (purine hydroxylase i) of aspergillus nidulans. the gene codes for a polypeptide of 1363 amino acids. the sequencing of a nonsense mutation, hxa5, proves formally that the clones isolated correspond to the hxa gene. the gene sequence is interrupted by three introns. similarity searches reveal two iron-sulfur centers and a nad/fad-binding domain and have enabled a consensus sequence to be determined for the molybdenum ...19957876088
the vitamin d3 hydroxylase-associated protein is a propionamide-metabolizing amidase enzyme.previously we isolated a novel protein that coimmunoprecipitates with the 1,25-dihydroxyvitamin d3-24r-hydroxylase and 25-hydroxyvitamin d3-1 alpha-hydroxylase. this kidney-specific protein found in the inner membrane of mitochondria is named the vitamin d3 hydroxylase-associated protein (vdhap). to determine a putative function for this protein, an extensive computer search of the deduced amino acid sequence of vdhap was performed. a blast homology search identified amino acid residues 133 thro ...19957840608
overexpression of two penicillin structural genes in aspergillus nidulans.we have placed two different penicillin structural genes from aspergillus nidulans, ipna (encoding isopenicillin n synthetase, ipns) and acya (encoding acyl-coa:6-aminopenicillanic acid acyltransferase, aat), under the control of the strong alca promoter [alca(p)]. single copies of these transcriptional fusions were targeted to the same chromosomal location and conditions have been worked out which simultaneously allow induction of the alca(p) and support penicillin biosynthesis. transcriptional ...19957823906
enzymatic synthesis of hydrophobic penicillins.our knowledge of the enzymes and genes involved in the biosynthesis of beta-lactam antibiotics has increased notably in the last decade. the purification to homogeneity of some of these proteins as well as their biochemical characterization has allowed some of them to be used for synthesizing many different penicillins and cephalosporin-like products in vitro. in this report we describe the most important advances in this field, placing special emphasis on the enzymatic synthesis of hydrophobic ...19958557558
allocation of random amplified polymorphic dna markers and enzyme activities to aspergillus nidulans and aspergillus tetrazonus chromosomes.chromosome-substituted haploid segregants of an a. nidulans x a. tetrazonus somatic hybrid were used to allocate several random amplified polymorphic dna and isoenzyme markers to parental chromosomes. twenty-six amplified dna fragments, and nine isoenzyme activities, including lactate dehydrogenase, superoxide dismutase, and arylesterase isoenzymes were assigned to chromosomes. chromosomes-specific markers were found for each a. nidulans and a. tetrazonus chromosome. these markers could be used ...19958572683
biosynthetic pathways of glycerol accumulation under salt stress in aspergillus nidulans.a culture of aspergillus nidulans (fgsc 359) was gradually adapted for growth in media containing up to 2 m nacl or was exposed to a salt shock with 2 m nacl. the intracellular glycerol level increased by about 7.9-fold in salt-adapted and 2.4-fold in salt-shocked cultures when compared to the unadapted culture. the biosynthetic pathway involved in the accumulation of glycerol was investigated under long-term salt adaptation and short-term salt shock. glycerol-3-phosphate dehydrogenase (ec 1.1.1 ...19958574901
integrative and replicative transformation of penicillium canescens with a heterologous nitrate-reductase gene.a wild isolate of penicillium canescens was subjected to mutagenesis, and 150 chlorate-resistant mutants were isolated and classified in respect of their ability to utilize various nitrogen sources. strains supposedly deficient in nitrate reductase have been transformed with the nitrate-reductase gene from aspergillus niger. transformation probably occurred by non-homologous integration of the transforming vector into the chromosome. co-transformation with the ama 1 replicating element from a. n ...19958575022
ethanol utilization regulatory protein: profile alignments give no evidence of origin through aldehyde and alcohol dehydrogenase gene fusion.the suggestion that the ethanol regulatory protein from aspergillus has its evolutionary origin in a gene fusion between aldehyde and alcohol dehydrogenase genes (hawkins ar, lamb hk, radford a, moore jd, 1994, gene 146:145-158) has been tested by profile analysis with aldehyde and alcohol dehydrogenase family profiles. we show that the degree and kind of similarity observed between these profiles and the ethanol regulatory protein sequence is that expected from random sequences of the same comp ...19958580855
the aspergillus nidulans bime (blocked-in-mitosis) gene encodes multiple cell cycle functions involved in mitotic checkpoint control and mitosis.the bime (blocked-in-mitosis) gene appears to function as a negative mitotic regulator because the recessive bime7 mutation can override certain interphase-arresting treatments and mutations, causing abnormal induction of mitosis. we have further investigated the role of bime in cell cycle checkpoint control by: (1) coordinately measuring mitotic induction and dna content of bime7 mutant cells; and (2) analyzing epistasis relationships between bime7 and 16 different nim mutations. a combination ...19958586660
pneumonia due to fonsecaea pedrosoi and cerebral abscesses due to emericella nidulans in a bone marrow transplant recipient. 19958589181
optimization of glucose oxidase production by aspergillus niger using genetic- and process-engineering techniques.wild-type aspergillus niger nrrl-3 was transformed with multiple copies of the glucose oxidase structural gene (god). the gene was placed under the control of the gpda promoter of a. nidulans. for more efficient secretion the alpha-amylase signal peptide from a. oryzae was inserted in front of god. compared to the wild type, the recombinant strain nrrl-3 (god3-18) produced up to four times more extracellular glucose oxidase under identical culture conditions. addition of yeast extract (2 gl-1) t ...19958590664
generation and characterization of nadh: ubiquinone oxidoreductase mutants in neurospora crassa. 19958592454
organisation of the mitochondrial genome of trichophyton rubrum. dna sequence analysis of the nd4 gene, the atpase subunit-6 gene, the ribosomal rna small-subunit gene, the nd6 gene, the coxiii gene, the atpase subunit-8 gene and six trna genes that correspond respectively to the tyrosine, lysine, glutamine, asparagine, isoleucine and tryptophan isoacceptors.we present the nucleotide sequence of a 5207-bp-long region of the mitochondrial genome of the dermatophyte trichophyton rubrum. this represents about 1/5th of the total genome and extends a previous study. from the 5' end of the present sequence, the order of genes is as follows: the end of the nd4 gene, the gene coding for subunit 6 of atpase, the gene coding for the small ribosomal rna (ssu rrna), the tyrosyl trna gene, the nd6 gene, the coxiii gene, the atpase 8 subunit gene and a cluster of ...19958593686
transformations of penicillium islandicum and penicillium frequentans that produce anthraquinone-related compounds.wild-type strains of penicillium islandicum and penicillium frequentans, which produce anthraquinone and related compounds, were transformed to benomyl and hygromycin b resistance. plasmids psv50 and pbt6, with benomyl-resistant beta-tublin genes, and plasmids pan7-1 and pdh25, with a bacterial hygromycin phosphotransferase gene under the control of aspergillus nidulans sequences, were used respectively. transformation frequencies with these plasmids were 10-20 transformants per micrograms of dn ...19958593690
biolistic transformation of the obligate plant pathogenic fungus, erysiphe graminis f.sp. hordei.particle gun acceleration appears to be a possible way to transform mycelium cells of obligate plant parasites growing on host surfaces. gus expression was obtained in e. graminis f.sp. hordei cells after bombardment with the gus gene under the control of the e. graminis f.sp. hordei β-tubulin promoter. three heterologous promoters, onefrom aspergillus nidulans and two from cochliobolus heterostrophus, gave very low or no expression of gus.19958595653
two family g xylanase genes from chaetomium gracile and their expression in aspergillus nidulans.with oligonucleotides based on the amino-terminal and internal amino-acid sequences of a xylanase, two xylanase genes, cgxa and cgxb, were isolated and sequenced from chaetomium gracile wild and mutant strains. each gene isolated from both strains was essentially the same as far as nucleotide sequences were compared. the mature cgxa and cgxb xylanases comprise 189 and 211 amino acids, respectively, and share 68.5% homology. the cgxa was found to be the major enzyme in the mutant strain. comparis ...19958595661
an alpha tubulin mutation suppresses nuclear migration mutations in aspergillus nidulans.microtubules and cytoplasmic dynein, a microtubule-dependent motor, are required for nuclei to move along the hyphae of filamentous fungi. nuclear migration in aspergillus nidulans is blocked by heat-sensitive (hs-) mutations in the nuda gene, which encodes dynein heavy chain, and the nudf gene, which encodes a g protein beta-subunit-like protein. hs- mutations in the nudc and nudg genes also prevent nuclear migration. we have isolated extragenic suppressor mutations that reverse the hs- phenoty ...19958601474
the nitrate reductase gene from a shoyu koji mold, aspergillus oryzae kbn616.a niad gene encoding nitrate reductase was isolated from aspergillus oryzae kbn616 and sequenced. the structural gene comprises 2973 bp and 868 amino acids, which showed a high degree of similarity to nitrate reductases from other filamentous fungi. the coding sequence is interrupted by six introns varying in size from 48 to 98 bp. the intron positions are all conserved among the niad genes from a. oryzae, aspergillus nidulans, and aspergillus niger. a homologous transformation system was develo ...19958520125
cre1, the carbon catabolite repressor protein from trichoderma reesei.in order to investigate the mechanism of carbon catabolite repression in the industrially important fungus trichoderma reesei, degenerated pcr-primers were designed to amplify a 0.7-bp fragment of the cre1 gene, which was used to clone the entire gene. it encodes a 402-amino acid protein with a calculated m(r) of 43.6 kda. its aa-sequence shows 55.6% and 54.7% overall similarity to the corresponding genes of aspergillus nidulans and a. niger, respectively. similarity was restricted to the aa-reg ...19958521952
dictyostelium myosin i double mutants exhibit conditional defects in pinocytosis.the functional relationship between three dictyostelium myosin is, myoa, myob, and myoc, has been examined through the creation of double mutants. two double mutants, myoa-/b- and myob-/c-, exhibit similar conditional defects in fluid-phase pinocytosis. double mutants grown in suspension culture are significantly impaired in their ability to take in nutrients from the medium, whereas they are almost indistinguishable from wild-type and single mutant strains when grown on a surface. the double mu ...19958522584
role of tryptophans in substrate binding and catalysis by dna photolyase. 19958524158
sok2 may regulate cyclic amp-dependent protein kinase-stimulated growth and pseudohyphal development by repressing transcription.yeast cyclic amp (camp)-dependent protein kinase (pka) activity is essential for growth and cell cycle progression. dependence on pka function can be partially relieved by overexpression of a gene, sok2, whose product has significant homology with several fungal transcription factors (stua from aspergillus nidulans and phd1 from saccharomyces cerevisiae) that are associated with cellular differentiation and development. deletion of sok2 is not lethal but exacerbates the growth defect of strains ...19958524252
gaip, a protein that specifically interacts with the trimeric g protein g alpha i3, is a member of a protein family with a highly conserved core domain.using the yeast two-hybrid system we have identified a human protein, gaip (g alpha interacting protein), that specifically interacts with the heterotrimeric gtp-binding protein g alpha i3. interaction was verified by specific binding of in vitro-translated g alpha i3 with a gaip-glutathione s-transferase fusion protein. gaip is a small protein (217 amino acids, 24 kda) that contains two potential phosphorylation sites for protein kinase c and seven for casein kinase 2. gaip shows high homology ...19958524874
characterization of the "promoter region" of the enolase-encoding gene enol from the anaerobic fungus neocallimastix frontalis: sequence and promoter analysis.the sequence of the neocallimastix frontalis enolase gene promoter was determined up to 1800 nucleotides 5' to the major transcriptional start point. the base composition of the enolase upstream sequence revealed a very a + t-rich profile (13.5% g + c) leading to many putative hairpin structures. the functional organization of the n. frontalis enolase promoter was investigated by heterologous transient-expression assays. dna fragments obtained by the sequential removal of sequences upstream of t ...19958536317
recombinational stability of replicating plasmids in aspergillus nidulans during transformation, vegetative growth and sexual reproduction.plasmids containing the ama1 replicon are capable of autonomous maintenance in aspergillus nidulans. it has been reported previously that these plasmids can form concatenates by recombination in a transformed mycelium, and up to 10% of molecules are involved in such events. the present study demonstrates that plasmid recombination, although frequent during transformation, rarely occurs during vegetative growth. as a result, the structure and phenotypic stability of ama1 plasmids generally remain ...19958536318
quantification of dna damage and repair in amino acid auxotrophs and uv-sensitive mutants of aspergillus nidulans using an elisa.an elisa used to investigate dna repair in mammalian cells has been adapted to investigate mutagen-induced dna damage and repair in protoplasts of aspergillus nidulans. the assay shows a reduced rate of repair of dna damage in methionine and arginine auxotrophs (methg and argb), which were shown previously to be hypersensitive to uv radiation and chemical mutagens. the assay also showed a considerably reduced ability to repair mutagen-induced damage in the uv-sensitive mutants uvsb and uvsh. the ...19958543032
analysis of the regulation of the aspergillus nidulans penicillin biosynthesis gene aat (pende), which encodes acyl coenzyme a:6-aminopenicillanic acid acyltransferase.the regulation of the aspergillus nidulans penicillin biosynthesis gene aat (pende), which encodes acyl coenzyme a:6-aminopenicillanic acid acyltransferase (aat), was analysed. major transcriptional start sites map within 100 nucleotides upstream from the aat initiation codon. to study the regulation of aat expression, various aat-lacz gene fusions were constructed, in which the aat promoter region was fused in frame with the escherichia coli lacz reporter gene. a. nidulans strains carrying reco ...19958544821
cell cycle. the nima kinase joins forces with cdc2.the nima and cdc2 protein kinases cooperate to regulate mitosis in aspergillus nidulans. nima-related pathways have now begun to emerge in higher eukaryotes.19958548283
toxicology of halogenated aliphatic hydrocarbons: structural and molecular determinants for the disturbance of chromosome segregation and the induction of lipid peroxidation.the induction of mitotic chromosome malsegregation, mitotic arrest and lethality by a set of 55 halogenated hydrocarbons was investigated. to this aim, genetic assays in the mould aspergillus nidulans, able to provide precise quantitative information on the end-points studied, were used throughout the work. the experimental data obtained were used to develop qsar models for the induction of aneuploidy, which pointed to a major role of electrophilicity as molecular determinant for the aneugenic p ...19958548852
beta-lactams. 19958688626
cinnamon bark oil, a potent fungitoxicant against fungi causing respiratory tract mycoses.cinnamic aldehyde has been identified as the active fungitoxic constituent of cinnamon (cinnamomum zeylanicum) bark oil. the fungitoxic properties of the vapours of the oil/active constituent against fungi involved in respiratory tract mycoses, i.e., aspergillus niger, a. fumigatus, a. nidulans a. flavus, candida albicans, c. tropicalis, c. pseudotropicalis, and histoplasma capsulatum, were determined in vitro as minimum inhibitory concentration (mic), minimum lethal concentration (mlc), inoculu ...19958834832
expression of a large number of novel testis-specific genes during spermatogenesis coincides with the functional reorganization of the male germ cell.structural and functional changes, essential for the formation of mature male germ cells, are known to take place at specific stages of the mammalian spermatogenic process. to identify novel genes that are involved in this developmental process, we have initiated a large-scale cdna sequencing project (hoog+, nucleic acids res. 19: 93-98, 1991; starborg et al., mol. reprod. dev. 33: 243-251, 1992; yuan et al., biol. reprod., 1995). five-hundred and forty cdnas have been isolated from testicular c ...19958645556
mutational analysis reveals dispensability of the n-terminal region of the aspergillus transcription factor mediating nitrogen metabolite repression.mutational analysis has enabled identification and localization of an upstream exon of the area gene of aspergillus nidulans mediating nitrogen metabolite repression. a mutation in the initiation codon and frameshift mutations, which revert by restoration of the reading frame, established the coding role of the exon and mutations affecting intron splicing in conjunction with dna sequencing of reverse transcriptase polymerase chain reaction (rt-pcr) products localized the coding region intron. th ...19958596437
tyrosine 495 is a key residue in the active site of galactose oxidase. 19958654695
purification and characterization of beta 2-tomatinase, an enzyme involved in the degradation of alpha-tomatine and isolation of the gene encoding beta 2-tomatinase from septoria lycopersici.lycopersicon species often contain the toxic glycoalkaloid alpha-tomatine, which is proposed to protect these plants from general microbial infection. however, fungal pathogens of tomato often are tolerant to alpha-tomatine and detoxification of alpha-tomatine may be how these pathogens avoid this potential barrier. as an initial step to evaluate this possibility, we have purfied to homogeneity a beta-1,2-d glucosidase from the tomato pathogen septoria lycopersici that hydrolyzes the beta-1,2-d ...19958664504
analysis of nuclear migration in aspergillus nidulans. 19958824456
extragenic suppressors of nudc3, a mutation that blocks nuclear migration in aspergillus nidulans.nuclear migration plays an important role in the growth and development of many organisms including the filamentous fungus aspergillus nidulans. we have cloned three genes from a. nidulans, nuda, nudc, and nudf, in which mutations affect nuclear migration. the nuda gene encodes the heavy chain of cytoplasmic dynein. the nudc gene encodes a 22-kd protein. the nudf gene was identified as an extra copy suppressor of the temperature sensitive (ts-) nudc3 mutation. the nudc3 mutation substantially de ...19958647384
the nima kinase: a mitotic regulator in aspergillus nidulans and vertebrate cells.cdc2 has been shown to regulate entry into mitosis in eukaryotic cells. however, in aspergillus nidulans, activation of cdc2 itself is not sufficient to trigger mitosis if another mitotic protein kinase, nima, is not activated. superficially, nima and cdc2 have analogous functions and are regulated in a similar manner. nima activity is tightly regulated during the cell cycle. overexpression of nima induces germinal vesicle breakdown in xenopus oocytes and promotes premature entry into mitosis in ...19959552363
sources of fungal linamarases.forty-four strains of aspergillus, penicillium, fusarium, trichoderma and rhizopus were grown on a liquid medium containing glucose and cassava-root extract. all of the aspergillus and fusarium strains, eight out of 10 penicillium strains and three of seven trichoderma strains showed linamarase activity. no such activity was detected in any rhizopus strain. the crude enzyme preparation from f. oxysporum had the highest affinity for linamarin whereas that from a. nidulans was the most heat-stable ...199524415020
expression of the aspergillus niger glucose oxidase gene in penicillium nalgiovense.the glucose oxidase gene (god) from aspergillus niger was expressed in penicillium nalgiovense under control of the latter's homologous transcription signals. the god protein was synthesized in an active form, leading to increased glucose oxidase activity. the expression vector was introduced into p. nalgiovense along with a selectable plasmid carrying the dominant amds marker gene of a. nidulans.199524414658
nuclear migration advances in fungi.nuclear migration encompasses three areas: separation of daughter nuclei during mitosis, congress of parental nuclei before they fuse during fertilization, and positioning of nuclei in interphase cells. this review deals primarily with interphase nuclear migration, which is crucial for events as disparate as vertebrate embryonic development and growth of fungal mycelia. mutants of aspergillus nidulans, neurospora crassa and saccharomyces cerevisiae have been particularly informative, and a detai ...199514732112
expression of active spinach glycolate oxidase in aspergillus nidulans.the biocatalytic production of glyoxylic acid from glycolic acid requires two enzymes: glycolate oxidase, which catalyzes the oxidation of glycolic acid by oxygen to produce glyoxylic acid and hydrogen peroxide, and catalase, which decomposes the byproduct hydrogen peroxide. as an alternative to isolation from the leaf peroxisomes of spinach, glycolate oxidase has now been cloned and expressed in transformants of aspergillus nidulans t580 at levels ranging from 1.7 to 36 iu/g dry wt. cells. the ...199618626962
combined expression of aspergillus nidulans endoxylanase x24 and aspergillus oryzae (alpha)-amylase in industrial baker's yeasts and their use in bread making.the aspergillus nidulans endoxylanase x24 and the aspergillus oryzae (alpha)-amylase cdnas were placed under the control of the saccharomyces cerevisiae actin promoter (pact1) and introduced into baker's yeast. bread made with transformants expressing both enzymes (yepact-amy-act-x24) showed a 30% increase in volume and reduced firmness in comparison with that produced with a commercial strain. endoxylanase x24 and (alpha)-amylase seem to act synergistically to improve the quality of bread in te ...199616535419
photodynamic effects of hypericin on photosynthetic electron transport and fluorescence of anacystis nidulans (synechococcus 6301).we investigated the photodynamic action of hypericin, a natural naphthodianthrone, on photosynthetic electron transport and fluorescence of the cyanobacterium anacystis nidulans (synechococcus 6301). the most drastic effect was the inactivation of photosynthetic oxygen evolution in the presence of the electron acceptor phenyl-p-benzoquinone in aerobic cells which required 1 hypericin/5 chlorophyll a for half-maximal effect. anaerobic a. nidulans was only partially inactivated and variable chloro ...199624271302
role of ca++/calmodulin binding proteins in aspergillus nidulans cell cycle regulation.the goal of this review is to summarise the current knowledge concerning the targets of ca++/calmodulin that are essential for cell cycle progression in lower eukaryotes. emphasis is placed on aspergillus nidulans since this is the only organism to date shown to posses essential ca++ dependent calmodulin activated enzymes. two such enzymes are the calmodulin activated protein phosphatase, calcineurin and the calmodulin dependent protein kinase. these proteins, each the product of a unique gene, ...19969552398
influence of zinc oxide on aspergillus species: a possible cause of local, non-invasive aspergillosis of the maxillary sinus.recently the appearance of radiopaque 'concrements' in the maxillary sinus was reported. these radiodense objects could be identified as root-filling material for teeth of the upper jaw containing zinc oxide. this suggested that excess root-filling material containing zinc oxide in the maxillary sinus could favour the formation of a local, non-invasive aspergillosis. to verify this hypothesis in vitro, we tested the influence of zinc oxide on aspergillus fumigatus, a. flavus, a. terreus, a. nidu ...19969009659
a study of protein-water exchange through the off-resonance roesy experiment: application to the dna-binding domain of alcr.in this communication a new nmr experiment for the safe observation and quantification of water-protein exchange phenomena is presented. it combines a water-selective pulse, offering chemical shift-based separation, and the off-resonance roesy dynamic filter, which permits the elimination of the unwanted intramolecular dipolar cross relaxation of protein protons. moreover, pulsed field gradients are used for the suppression of radiation damping and the solvent signal. the straightforward incorpo ...19969008364
purification and properties of beta-galactosidase from aspergillus nidulans.beta-galactosidase from mycelial extract of aspergillus nidulans has been purified by substrate affinity chromatography and used to obtain anti-beta-galactosidase polyclonal antibodies. a. nidulans growing in lactose as carbon source synthesizes one active form of beta-galactosidase which seems to be a multimeric enzyme of 450 kda composed of monomers with 120 and 97 kda. although the enzyme was not released to the culture medium, some enzymatic activity was detected in a cell-wall extract, thus ...19969018692
separation and partial purification of beta-glucosidase and two endoglucanases in aspergillus niveus.the thermotolerant aspergillus niveus strain rmf 7883 was grown in czapek medium, with filter paper cellulose. the proportion of mycelial-bound to extracellular enzymes was studied. most of the beta-glucosidase (80.9%) and endoglucanases (78.3%) activities were extracellular. the extracellular endoglucanases and beta-glucosidase were separated and partially purified by sephadex g-100 gel filtration, followed by ion exchange chromatography on cm-trisacryl m. two extracellular endoglucanases, eg i ...19969019140
nitrogen metabolite signalling involves the c-terminus and the gata domain of the aspergillus transcription factor area and the 3' untranslated region of its mrna.area is a gata transcription factor which mediates nitrogen metabolite repression in aspergillus nidulans in response to intracellular glutamine levels. we have identified and localized three elements important to modulation of area function: a region of 13 residues within the dna-binding gata domain which forms a putative extended loop structure, the 12 c-terminal residues, and sequences within a 218 nucleotide region of the 3' utr. the 12 c-terminal residues are also required for transcription ...19968654376
sorption of cadmium by filamentous soil fungi.the article presents the evaluation of the short-term sorption of cd by selected soil fungi. the freundlich adsorption isotherm method for metal sorption modelling was applied. fungal strains belonging to two classes, zygomycetes and ascomycetes, were used. altogether, six species from ascomycetes (a. niger, a. nidulans, ps. boydii, t. koningii, p. janthinellum, p. verrucosum) and three from zygomycetes (r. rhizopodiformis, r. oryzae, r. pusillus) were examined. these fungi were selected for exp ...19968997697
cloning of the polyketide synthase gene atx from aspergillus terreus and its identification as the 6-methylsalicylic acid synthase gene by heterologous expression.southern blot analysis of genomic dnas of several fungi that produce polyketide compounds with the 6-methylsalicylic acid synthase (msas) gene of penicillium patulum as a probe indicated the presence of an msas-homologous gene in the (+)-geodin-producing strain imi 16,043 of aspergillus terreus. the gene, designated atx was cloned from an a. terreus genomic dna library and 7588 bp of the gene together with its flanking regions were sequenced to reveal the presence of a 5.5 kb open reading frame ...19969003280
delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine synthetase is a rate limiting enzyme for penicillin production in aspergillus nidulans.the acva gene from aspergillus nidulans encoding delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine (acv) synthetase was overexpressed by replacing the wild-type acva promoter with the ethanol dehydrogenase promoter, alcap, from a. nidulans. the expression level of alcap was determined using a strain in which the reporter gene, lacz, is under the control of alcap, and was found to be up to 100 times greater than that from the acva promoter when induced in fermentation conditions. penicillin yields ...19969003303
gene expression from replicating plasmids in aspergillus nidulans.plasmids bearing the ama1 replicator from aspergillus nidulans are capable of extrachromosomal replication in this fungus as well as in other species. synthetic plasmids bearing the moderately expressed argb gene and the highly expressed, inducible beta-galactosidase gene (bgas) were introduced into fungal cells. expression of both genes was monitored by northern hybridization. it was demonstrated that transcription of bgas is induced and repressed normally, irrespective of whether the gene is i ...19969003309
a dictyostelium myosin i plays a crucial role in regulating the frequency of pseudopods formed on the substratum.analysis of the motile behavior of a strain of dictyostelium lacking a myosin i, myoa, revealed that this mutant strain formed pseudopods and turned twice as frequently as wild type cells [titus et al., 1993: mol. biol. cell 4:233-246]. the basis for this aberrant behavior has been explored using three-dimensional reconstructions of translocating cells. wild type cells form approximately 40% of pseudopods on the substratum and 60% off the substratum. the majority of pseudopods formed on the subs ...19968824735
the plasmid replicator ama1 in aspergillus nidulans is an inverted duplication of a low-copy-number dispersed genomic repeat.the ama1 sequence was isolated from a genomic library of aspergillus nidulans on the basis of its ability to enhance transformation frequency and generate phenotypically unstable transformants in this fungus. these properties were previously shown to be the result of extrachromosomal replication of ama1-bearing plasmids. here we demonstrate that ama1 is an inverted duplication of a sequence which has other isolated genomic copies. these sequences (mobile aspergillus transformation enhancers, or ...19968830247
translational initiation competence, 'leaky scanning' and translational reinitiation in area mrna of aspergillus nidulans.(1) aug codons that either permit or prevent 'leaky scanning' of mrna encoding area, the transcriptional activator mediating nitrogen metabolite repression in aspergillus nidulans, have been identified. the consensus context for a strong initiation codon (i.e. one preventing 'leaky scanning') derived from this work is gxx aug c/ucx. however, aug codons which do not conform to this consensus are nevertheless able to initiate translation. (2) translational reinitiation can occur within area mrna, ...19968830259
control of metabolic flux through the quinate pathway in aspergillus nidulans.the quinic acid ulitization (qut) pathway in aspergillus nidulans is a dispensable carbon utilization pathway that catabolizes quinate to protocatechuate via dehydroquinate and dehydroshikimate(dhs). at the usual in vitro growth ph of 6.5, quinate enters the mycelium by means of a specific permease and is converted into pca by the sequential action of the enzymes quinate dehydrogenase, 3-dehydroquinase and dhs dehydratase. the extent of control on metabolic flux exerted by the permease and the t ...19968670107
two s-phase checkpoint systems, one involving the function of both bime and tyr15 phosphorylation of p34cdc2, inhibit nima and prevent premature mitosis.we demonstrate that there are at least two s-phase checkpoint mechanisms controlling mitosis in aspergillus. the first responds to the rate of dna replication and inhibits mitosis via tyrosine phosphorylation of p34cdc2. cells unable to tyrosine phosphorylate p34cdc2 are therefore viable but are unable to tolerate low levels of hydroxyurea and prematurely enter lethal mitosis when s-phase is slowed. however, if the nima mitosis-promoting kinase is inactivated then non-tyrosine-phosphorylated p34 ...19968670863
quantitative analysis of gene expression in sexual structures of aspergillus nidulans by sequencing of 3'-directed cdna clones.we constructed a 3'-directed cdna library of cleistothecia and hülle cells of aspergillus nidulans to examine gene expression patterns of the sexual structures and to have probes necessary to isolate sexual structure-specific genes. sequencing of 360 randomly selected cdna clones yielded 272 expressed sequence tags (ests), most of which probably represent frequently or less expressed genes in sexual structures of a. nidulans. among the 272 ests, 33 ests (87 cdna clones) appeared more than once a ...19968674973
characterisation of the aspergillus nidulans fra1 mutant: hexose phosphorylation and apparent lack of involvement of hexokinase in glucose repression.hexose phosphorylation was studied in aspergillus nidulans wild-type and in a fructose non-utilising mutant (fra). the data indicate the presence of at least one hexokinase and one glucokinase in wild-type a. nidulans, while the fra1 mutant lacks hexokinase activity. the a. nidulans gene encoding hexokinase was isolated by complementation of the fra1 mutation. the absence of hexokinase activity in the fra1 mutant did not interfere with glucose repression of the enzymes involved in alcohol and l- ...19968674991
identification of a major cis-acting dna element controlling the bidirectionally transcribed penicillin biosynthesis genes acva (pcbab) and ipna (pcbc) of aspergillus nidulans.the beta-lactam antibiotic penicillin is produced as a secondary metabolite by some filamentous fungi. in this study, the molecular regulation of the aspergillus (emericella) nidulans penicillin biosynthesis genes acva (pcbab) and ipna (pcbc) was analyzed. acva and ipna are divergently oriented and separated by an intergenic region of 872 bp. translational fusions of acva and ipna with the two escherichia coli reporter genes lacz and uida enabled us to measure the regulation of both genes simult ...19968682797
the tama gene of aspergillus nidulans contains a putative zinc cluster motif which is not required for gene function.expression of many nitrogen catabolic enzymes is controlled by nitrogen metabolite repression in aspergillus nidulans. although the phenotypes of tama mutants have implicated this gene in nitrogen regulation, its function is unknown. we have cloned the tama gene by complementation of a new tama allele. the tama sequence shares significant homology with the uga35/dal81/durl gene of saccharomyces cerevisiae. in vitro mutagenesis of sequences encoding a putative zinc cluster dna binding domain indi ...19968655534
[test for the effects of mutagenic toxic fungal metabolites originating from municipal landfill sites].the purpose of the study is to assess the mutagenic effect of mycotoxins produced by moulds growing on municipal landfill sites. mutagenicity of toxic fungal metabolites was determined by the salmonella plate incorporation assay with two strains of bacteria: ta98 and ta100, with and without metabolic activation. the results obtained indicate that there is a severe hazard caused by these mycotoxins detected main by ta98 with metabolic activation. the most mutagenic mixture of mycotoxins acting di ...19968656997
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