suppression and enhancement of the aspergillus nidulans medusa mutation by altered dosage of the bristle and stunted genes.asexual reproduction in aspergillus nidulans is characterized by the orderly differentiation of multicellular reproductive structures (conidiophores) and chains of uninucleate conidia (spores). mutations in the developmental modifier medusa (meda) result in aberrant conidiophores with branching chains of reiterated reproductive cells (metulae), delayed conidial differentiation and frequent reinitiation of secondary conidiophores. we show that incorrect morphology is in part a consequence of modi ...19968722771
saccharomyces cerevisiae tec1 is required for pseudohyphal growth.diverse eukaryotic organisms share developmental transcription factors with homologous dna-binding domains. we showed that the developmental regulator abaa, a member of the atts/tea (abaa, tef-1, tec1, scalloped/tef-1, tec1, abaa) class of transcription factors of the filamentous fungus aspergillus nidulans, induces pseudohyphal development in the yeast saccharomyces cerevisiae. the s. cerevisiae homologue of abaa, tec1p, is required for this morphological transition. we provide evidence that te ...19968730867
multiple copies of mate elements support autonomous plasmid replication in aspergillus nidulans.the ama1 sequence is an efficient plasmid replicator and transformation enhancer in aspergillus nidulans. it comprises two long perfect inverted repeats (mate elements) flanking a short, unique, central spacer. subclone analysis indicates that the complete inverted duplication, but not the unique central spacer, is necessary for efficient plasmid replication. the smallest fragments able to affect transformation efficiency lie within the at-rich portions of the inverted repeats. we demonstrate th ...19968733240
a newly identified gene cluster in aspergillus nidulans comprises five novel genes localized in the alc region that are controlled both by the specific transactivator alcr and the general carbon-catabolite repressor crea.ethanol-utilization in aspergillus nidulans is mediated by alcohol dehydrogenase i and aldehyde dehydrogenase encoded by alca and alda, respectively. both genes are under the transcriptional control of the specific activator alcr and the general carbon catabolite repressor crea. the alcr and alca genes are closely linked in chromosome vii; alda is located in chromosome viii. we have identified five other transcripts that are expressed from the same genomic region as alca and alcr. they are induc ...19968736527
characterization of a penicillium chrysogenum gene encoding a pacc transcription factor and its binding sites in the divergent pcbab-pcbc promoter of the penicillin biosynthetic cluster.previous work established that ph regulation of gene expression in aspergillus nidulans, a major determinant of penicillin biosynthesis, is mediated by the zinc-finger transcription factor pacc, an activator of transcription of the isopenicillin n synthase gene. we characterize here the pacc gene from the efficient penicillin producer penicillium chrysogenum, which functionally complements an a. nidulans pacc null mutation. it encodes a 641-residue polypeptide showing 64% identify to a. nidulans ...19968736532
isolation of opportunistic fungi from bronchoalveolar lavage of compromised hosts in isfahan, this study, bronchoalveolar lavage (bal) specimens from 247 immunocompromised patients were investigated for the incidence of opportunistic fungi. in the direct examination and culture of the specimens, 5 (2.02%) of filamentous fungi and 55 (22.26%) yeasts were isolated and identified as follows: aspergillus fumigatus (2), a. terreus (1), a. nidulans (1), mucor sp. (1), candida albicans (29), c. glabrata (3), c. parapsilosis (1), trichosporon beigelii (1), candida sp. (13) and unknown yeasts ...19968751826
the secondary structure and phylogenetic relationship deduced from complete nucleotide sequence of mitochondrial small subunit rrna in yeast hansenula wingei.we have accomplished the nucleotide sequence of the 1537 bp mitochondrial gene coding for small subunit (ssu) rrna of yeast hansenula wingei, and also determined the 5'- and 3'-termini by s1 nuclease mapping. eight universally conserved (u) elements of the ssu rrna were identified. comparison of u regions among five fungal mitochondrial ssu rrna shows the striking similarity between h. wingei and saccharomyces cerevisiae. the construction of the secondary structure revealed a core structure simi ...19968752867
expression of the sclerotinia sclerotiorum polygalacturonase pg1 gene: possible involvement of crea in glucose catabolite repression.northern-blot analysis of rna isolated from sclerotinia sclerotiorum grown on either glucose or polygalacturonate as the sole carbon source showed that pg1, encoding a neutral polygalacturonase, was not expressed during growth in both media. in contrast, transcripts of this gene were detected during infection of sunflower germlings. analysis of the promoter sequence revealed a number of cis-acting sequences known to regulate the expression of many fungal promoters. protein-dna-binding experiment ...19968753653
isolation of a gene involved in 1,3-beta-glucan synthesis in aspergillus nidulans and purification of the corresponding protein.saccharomyces cerevisiae has two highly homologous genes, fks1 and fks2, which encode interchangeable putative catalytic subunits of 1,3-beta-glucan synthase (gs), an enzyme that synthesizes an essential polymer of the fungal cell wall. to determine if gs in aspergillus species is similar, an fks homolog, fksa, was cloned from aspergillus nidulans by cross-hybridization, and the corresponding protein was purified. sequence analysis revealed a 5,716-nucleotide coding region interrupted by two 56- ...19968755864
the cyanobacterial thioredoxin gene is required for both photoautotrophic and heterotrophic growth.the gene encoding thioredoxin in the facultative heterotrophic cyanobacterium synechocytis sp. pcc 6803 (trxa) has been cloned by heterologous hybridization using the corresponding gene trxm from the cyanobacterium anacystis nidulans as a probe. the deduced amino acid sequence of trxa predicts a protein of relative molecular weight of 11,750 and has strong identity with its cyanobacterial counterparts and other m-type thioredoxins of photo-synthetic eukaryotes. the trxa gene has been expressed e ...19968756494
nut1, a major nitrogen regulatory gene in magnaporthe grisea, is dispensable for pathogenicity.nut1, a gene homologous to the major nitrogen regulatory genes nit-2 of neurospora crassa and area of aspergillus nidulans, was isolated from the rice blast fungus, magnaporthe grisea. nut1 encodes a protein of 956 amino acid residues and, like nit-2 and area, has a single putative zinc finger dna-binding domain. functional equivalence of nut1 to area was demonstrated by introducing the nut1 gene by dna-mediated transformation into an area loss-of-function mutant of a. nidulans. the introduced n ...19968757395
the cu,zn superoxide dismutases of aspergillus flavus, aspergillus niger, aspergillus nidulans, and aspergillus terreus: purification and biochemical comparison with the aspergillus fumigatus cu,zn superoxide,zn superoxide dismutases (sods) have been purified to homogeneity from aspergillus flavus and a. niger, which are significant causative agents of aspergillosis, and from a. nidulans and a. terreus, which are much rarer causative agents of disease, using a combination of isoelectric focusing and gel filtration fast protein liquid chromatography. the purified enzymes have been compared with the previously described sod from the most important pathogen in the genus, a. fumigatus (m. d. holdom, r ...19968757871
cell cycle regulation in aspergillus by two protein kinases.great progress has recently been made in our understanding of the regulation of the eukaryotic cell cycle, and the central role of cyclin-dependent kinases is now clear. in aspergillus nidulans it has been established that a second class of cell-cycle-regulated protein kinases, typified by nima (encoded by the nima gene), is also required for cell cycle progression into mitosis. indeed, both p34cdc2/cyclin b and nima have to be correctly activated before mitosis can be initiated in this species, ...19968760343
the 2.8 a structure of a t = 4 animal virus and its implications for membrane translocation of rna.simple rna animal viruses generally enter cells through receptor-mediated endocytosis followed by acid ph dependent release and translocation of rna across the endosomal membrane. the t = 3 nodaviruses contain prefabricated pentameric helical bundles that are cleaved from the remainder of the subunits by an assembly-dependent auto-proteolysis and they are positioned for release through 5-fold axes of the particle. we previously proposed that these bundles may serve as conduits for rna membrane t ...19968760498
a study of the structural basis of the ability of chlorinated alkanes and alkenes to induce aneuploidy and toxicity in the mold aspergillus nidulans.a knowledge-based system (multicase) was applied to the elucidation of the structural basis of the induction of aneuploidy and growth inhibition by a group of chlorinated alkanes and alkenes in aspergillus nidulans. it was found that while there were commonalities in the structural determinants associated with fungicidal and fungostatic activities, there were none between these and the structures associated with the induction of aneuploidy. moreover, there did not appear to be a commonality betw ...19968764947
[effect of zinc oxide on aspergillus species: a possible cause of local noninvasive aspergillosis of the maxillary sinus].during the last years the appearance of radiopaque concrements in the maxillary sinus was reported. these 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 development of a local, non-invasive aspergillosis. therefore, we tested aspergillus fumigatus, a. flavus, a. terreus, a. nidulans and a. niveus for the influence of zinc oxide. cza-pek-do ...19968767264
on the consistency of a physical mapping method to reconstruct a chromosome in vitro.during recent years considerable effort has been invested in creating physical maps for a variety of organisms as part of the human genome project and in creating various methods for physical mapping. the statistical consistency of a physical mapping method to reconstruct a chromosome, however, has not been investigated. in this paper, we first establish that a model of physical mapping by binary fingerprinting of dna fragments is identifiable using the key assumption-for a large randomly genera ...19968770604
screening of medicinal plants for induction of somatic segregation activity in aspergillus nidulans.knowledge about mutagenic properties of plants commonly used in traditional medicine is limited. a screening for genotoxic activity was carried out in aqueous or alcoholic extracts prepared from 13 medicinal plants widely used as folk medicine in cuba: lepidium virginicum l. (brassicaceae): plantago major l. and plantago lanceolata l. (plantaginaceae); ortosiphon aristatus blume, mentha x piperita l., melissa officinalis l. and plectranthus amboinicus (lour.) spreng. (lamiaceae); cymbopogon citr ...19968771452
isolation and characterization of the nuclease o gene (nuco) from aspergillus oryzae.nuclease o in the mycelia of aspergillus oryzae has been purified 55-fold by successive steps of chromatography from the filtrate of the autolyzate. the molecular mass of nuclease o was 32 kda, as estimated by sds polyacrylamide-gel electrophoresis. the nuclease o gene (nuco) encoding this enzyme was cloned and sequenced. the open reading frame is interrupted by four introns with conserved splice sites and contains 328 amino-acid residues of the mature enzyme. a. nidulans transformants obtained ...19968781174
molecular cloning and expression in saccharomyces cerevisiae of two aspergillus nidulans xylanase genes.two aspergillus nidulans genes, xlna and xlnb, encoding the x22 and x24 xylanases from this fungus, respectively, have been cloned and sequenced. their cdnas have been expressed in a laboratory saccharomyces cerevisiae strain under the control of a constitutive yeast promoter, resulting in the construction of recombinant xylanolytic yeast strains.19968787417
mitochondrial inheritance in aspergillus nidulans.mitochondrial chloramphenicol and oligomycin resistance mutations were used to investigate mitochondrial inheritance in a. nidulans. mitochondrial rflps could not be used to distinguish between paternal and maternal mitochondria because none were detected in the 54 isolates investigated. several thousand ascospores from each of 111 hybrid cleistothecia from 21 different crosses between 7 heterokaryon incompatible isolates were tested for biparental inheritance. all mitochondrial inheritance was ...19968801189
isolation and characterization of a calmodulin-encoding cdna from the pathogenic fungus histoplasma capsulatum.we describe in this paper the isolation and complete sequence of a calmodulin (cam) encoding cdna from the dimorphic pathogenic fungus histoplasma capsulatum (genbank accession u12505). the deduced amino acid sequence was identical to the cam of aspergillus nidulans and had only one amino acid difference from the cam of neurospora crassa. saccharomyces cerevisiae cam, however, has only about 60% amino acid identity compared with h. capsulatum. these data further support the close relationship of ...19968803795
[regulation of folate metabolism in fungi: aspergillus nidulans as an experimental model]. 19968805185
the orla gene from aspergillus nidulans encodes a trehalose-6-phosphate phosphatase necessary for normal growth and chitin synthesis at elevated temperatures.a cosmid carrying the orla gene from aspergillus nidulans was identified by complementation of an orla1 mutant strain with dna from the pkby2 cosmid library. an orla1 complementing fragment from the cosmid was sequenced. orla encodes a predicted polypeptide of 227 amino acids (26360 da) that is homologous to a 211-amino-acid domain from the polypeptide encoded by the saccharomyces cerevisiae tps2 gene and to almost the entire escherichia coli otsb-encoded polypeptide. tps2 and otsb each specify ...19968809779
the chsd and chse genes of aspergillus nidulans and their roles in chitin synthesis.two chitin synthase genes, chsd and chse, were identified from the filamentous ascomycete aspergillus nidulans. in a region that is conserved among chitin synthases, the deduced amino acid sequences of chsd and chse have greater sequence identity to the polypeptides encoded by the saccharomyces cerevisiae chs3 gene (also named csd2, cal1, dit101, and kti1) and the candida albicans chse gene than to other chitin synthases. chse is more closely related to the chs3 genes, and this group constitutes ...19968810520
the isolation of a dol-p-man synthase from ustilago maydis that functions in saccharomyces cerevisiae.genomic dnas from several fungi were screened for a homologous sequence to saccharomyces cerevisiae dpm1, an essential gene which encodes dolichyl phosphoryl mannose synthase. the fungi examined included aspergillus nidulans, neurospora crassa, schizophyllum commune and ustilago maydis. only u. maydis gave a significant signal after southern hybridization using dpm1 as a probe. the ustilago homolog was subsequently cloned and sequenced. the predicted protein of 294 amino acids has 60% identity t ...19968813763
purification and partial characterization of the high and low molecular weight form (s- and f-form) of invertase secreted by aspergillus nidulans.two forms of secreted invertase have been purified from aspergillus nidulans by ion-exchange and gel-filtration chromatography. s-invertase gave a single, broad, glycoprotein band on page and sds-page corresponding in size to 185 and 78 kda, respectively, compared with 94 and 110 kda for f-invertase. the carbohydrate of s-invertase contained mainly mannose (14%) and less galactose (5%) whereas the f-form yielded mainly galactose (29%) and less mannose (12%). three sharp bands of enzymically acti ...19968814228
aspergillus endocarditis in chronic granulomatous disease.we report the first case, to our knowledge, of aspergillus endocarditis in chronic granulomatous disease in a patient who also had an atrial septal defect. a diagnosis was made on culture of the organism from the mass despite extensive prior investigation. the presence of distinctive skin lesions as a diagnostic clue of fungaemia is highlighted. possible advances in diagnosis by detection of fungal cell wall components and in prophylaxis by use of itraconazole are referred to. we conclude that f ...19968816221
fast dissociation of phe-trna synthetase from aspergillus nidulans immobilized on sepharose-6b column by nacl.phenylalanyl-trna2) synthetase from aspergillus nidulans was efficiently immobilised to sepharose 6b column containing phenylalanine as the ligand. nacl was found to be a potent dissociating agent for the immobilised enzyme. while 0.5 m nacl in discontinuous elution showed a slow impetus on dissociation giving a plateaux profile, a solution of 0.8 m nacl made the elution rapid giving a sharp peak. on the other hand, in a gradient (continuous) elution the rapidity of dissociation was found to be ...19968819846
the cloning and sequencing of the alcb gene, coding for alcohol dehydrogenase ii, in aspergillus nidulans.alcohol dehydrogenase ii (adh ii, structural gene alcb) was purified from a strain h1035, bia1; alce1; alc500 alcd1, which produces 100-times more adh ii activity than the alcaalcr deletion strain (alc500). antibodies were raised against this adh, and were used to screen a cdna library in lambda gt11. we have isolated the gene for an adh which is over-expressed in h1035, and which we believe to be the alcb gene: cdna and genomic clones were sequenced. the sequence contains three introns and enco ...19968821658
isolation of differentially expressed cdna clones from salt-adapted aspergillus nidulans.differentially expressed cdna clones were isolated from salt-adapted aspergillus nidulans (fgsc #359). poly (a)+ rna from adapted mycelia was used to construct a lambda uni-zap cdna library. the library was screened with mixed subtracted cdna probes. three-hundred and fifty-seven positive plaques were isolated in the primary screening. sixty-two randomly selected plaques were purified and placed into eight different cross-hybridization groups. a representative cdna from each group was used to st ...19968821659
analysis of nuclear migration in aspergillus nidulans. 19958824456
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
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
isolation of laccase gene-specific sequences from white rot and brown rot fungi by pcr.degenerate primers corresponding to the consensus sequences of the copper-binding regions in the n-terminal domains of known basidiomycete laccases were used to isolate laccase gene-specific sequences from strains representing nine genera of wood rot fungi. all except three gave the expected pcr product of about 200 bp. computer searches of the databases identified the sequence of each of the pcr products analyzed as a laccase gene sequence, suggesting the specificity of the primers. pcr product ...19968837429
cloning, molecular analysis and insertional mutagenesis of the bidirectional hydrogenase genes from the cyanobacterium anacystis nidulans.among cyanobacteria, the heterocystous, n2-fixing anabaena variabilis and the unicellular anacystis nidulans have recently been shown to possess an nad+-dependent, bidirectional hydrogenase. a 5.0 kb dna segment of the a. nidulans genome is now identified to harbor the structural genes hoxuyh coding for three subunits of the bidirectional hydrogenase. the gene arrangement in a. nidulans and in a. variabilis is remarkably dissimilar. in a. nidulans, but not in a. variabilis, the four accessory ge ...19968843154
an extragenic suppressor of the mitosis-defective bimd6 mutation of aspergillus nidulans codes for a chromosome scaffold protein.we previously identified a gene, bimd, that functions in chromosome segregation and contains sequences suggesting that it may be a dna-binding protein. two conditionally lethal mutations in bimd arrest with aberrant mitotic spindles at restrictive temperature. these spindles have one-third the normal number of microtubules, and the chromosomes never attach to the remaining microtubules. for this reason, we hypothesized that bimd functioned in chromosome segregation, possibly as a component of th ...19968849887
cytokinesis in aspergillus nidulans is controlled by cell size, nuclear positioning and mitosis.the mycelium of aspergillus nidulans is composed of multinucleate cellular compartments delimited by crosswalls called septa. septum formation is dependent on mitosis and requires the recruitment of actin to the site of septum formation. employing a collection of temperature sensitive nuclear distribution (nuda2, nudc3 and nudf7), nuclear division (nima5, hfab3), and septation (sepd5, sepg1) mutants, we have investigated the interdependency among nuclear positioning, mitosis, and cell growth in ...19968856514
analysis of mutations in the crea gene involved in carbon catabolite repression in aspergillus nidulans.the molecular nature of a number of crea mutant alleles has been determined. three alleles analysed are missense mutations in the dna binding domain and predicted to reduce but not abolish binding. of the other four alleles, two result from frameshifts: one has a nonsense mutilation and the other has an inversion. all four alleles result in truncations of the protein after the zinc finger domain, such that the protein no longer contains at least the carboxy terminal 145 amino acids, so identifyi ...19968864218
nuva, an aspergillus nidulans gene involved in dna repair and recombination, is a homologue of saccharomyces cerevisiae rad18 and neurospora crassa uvs-2.a 40 kb genomic clone and 2.3 kb ecori subclone that rescued the dna repair and recombination defects of the aspergillus nidulans nuva11 mutant were isolated and the subclone sequenced. the subclone hybridized to a cosmid in a chromosome-specific library confirming the assignment of nuva to linkage group iv and indicating its closeness to bimd. amplification by pcr clarified the relative positions of nuva and bimd. a region identified within the subclone, encoding a c3hc4 zinc finger motif, was ...19968868425
conformational changes and the role of metals in the mechanism of type ii dehydroquinase from aspergillus nidulans.we have investigated the involvement of metal ions and conformational changes in the elimination reaction catalysed by type ii dehydroquinase from aspergillus nidulans. mechanistic comparisons between dehydroquinases and aldolases raised the possibility that, by analogy with type ii aldolases, type ii dehydroquinases may require bivalent metal ions for activity. this hypothesis was tested by a combination of metal analysis, effects of metal chelators and denaturation/renaturation experiments, al ...19968870678
a temperature-sensitive splicing mutation in the bimg gene of aspergillus produces an n-terminal fragment which interferes with type 1 protein phosphatase function.progression through anaphase requires high levels of type 1 protein phosphatase (pp1) activity in a variety of eukaryotes, including aspergillus nidulans. a conditional lethal, temperature-sensitive mutant in one of the aspergillus pp1 genes, bimg, prevents the normal completion of anaphase when cells are grown at restrictive temperature and this has been shown to be due to a reduction in type 1 phosphatase activity. we show that the bimg11 allele is recessive to the wild-type allele in heterozy ...19968887549
isolation of two apsa suppressor strains in aspergillus nidulans.aspergillus nidulans reproduces asexually with single nucleated conidia. in apsa (anucleate primary sterigmata) strains, nuclear positioning is affected and conidiation is greatly reduced. to get further insights into the cellular functions of apsa, aconidial apsa strains were mutagenized and conidiating suppressor strains were isolated. the suppressors fell into two complementation groups, sama and samb (suppressor of anucleate metulae), sama mapped on linkage group 1 close to pyrg. the mutant ...19968889518
rna-mediated transformation in aspergillus nidulans recovers gene functions lost by deletion or by point mutations.this work presents the results on two different approaches of rna-mediated transformation in a. nidulans: a) the receptor strain was an argb2 (iii) mutant deficient in arginine (otcase deficient), and b) the receptor was an a. nidulans mutant defective in nitrate reductase synthesis due to a deletion in the niad gene (viii). the analyses of the arg+ and the nia+ retrotransformants allowed an insight on the fate and inheritance of the newly acquired characteristics. the occurrence and the study o ...19968891357
identification of bime as a subunit of the anaphase-promoting complex.the initiation of anaphase and exit from mitosis require the activation of a proteolytic system that ubiquitinates and degrades cyclin b. the regulated component of this system is a large ubiquitin ligase complex, termed the anaphase-promoting complex (apc) or cyclosome. purified xenopus laevis apc was found to be composed of eight major subunits, at least four of which became phosphorylated in mitosis. in addition to cdc27, cdc16, and cdc23, apc contained a homolog of aspergillus nidulans bime, ...19968895470
identification of subunits of the anaphase-promoting complex of saccharomyces cerevisiae.entry into anaphase and proteolysis of b-type cyclins depend on a complex containing the tetratricopeptide repeat proteins cdc16p, cdc23p, and cdc27p. this particle, called the anaphase-promoting complex (apc) or cyclosome, functions as a cell cycle-regulated ubiquitin-protein ligase. two additional subunits of the budding yeast apc were identified: the largest subunit, encoded by the apc1 gene, is conserved between fungi and vertebrates and shows similarity to bimep from aspergillus nidulans. a ...19968895471
the aspergillus flba rgs domain protein antagonizes g protein signaling to block proliferation and allow development.flba encodes an aspergillus nidulans rgs (regulator of g protein signaling) domain protein that is required for control of mycelial proliferation and activation of asexual sporulation. we identified a dominant mutation in a second gene, fada, that resulted in a very similar phenotype to flba loss-of-function mutants. analysis of fada showed that it encodes the alpha-subunit of a heterotrimeric g protein, and the dominant phenotype resulted from conversion of glycine 42 to arginine (fada(g42r)). ...19968895563
ca(2+)/calmodulin-dependent kinase is essential for both growth and nuclear division in aspergillus nidulans.the calmodulin gene has been shown to be essential for cell cycle progression in a number of eukaryotic organisms. in vertebrates and aspergillus nidulans the calmodulin dependence also requires calcium. we demonstrate that the unique gene encoding a multifunctional calcium/calmodulin-dependent protein kinase (camk) is also essential in a. nidulans. this enzyme is required both for the nuclear division cycle and for hyphal growth, because spores containing the disrupted gene arrest with a single ...19968898358
aspergillus nidulans stcp encodes an o-methyltransferase that is required for sterigmatocystin biosynthesis.the aspergillus nidulans stcp gene was previously identified as a transcribed region associated with a cluster of genes proposed to be involved in sterigmatocystin biosynthesis (d. w. brown, j.-h. yu, h. s. kelkar, m. fernandes, t. c. nesbitt, n. p. keller, t. h. adams, and t. j. leonard, proc. natl. acad. sci. usa 93:1418-1422, 1996). stcp was predicted to encode a methyltransferase responsible for conversion of demethylsterig-matocystin to sterigmatocystin. here we demonstrate that disruption ...19968900026
parods--a study of parallel algorithms for ordering dna sequences.a suite of parallel algorithms for ordering dna sequences (termed parods) is presented. the algorithms in parods are based on an earlier serial algorithm, ods, which is a physical mapping algorithm based on simulated annealing. parallel algorithms for simulated annealing based on markov chain decomposition are proposed and applied to the problem of physical mapping. perturbation methods and problem-specific annealing heuristics are proposed and described. implementations of parallel single instr ...19968902353
three binding sites for the aspergillus nidulans pacc zinc-finger transcription factor are necessary and sufficient for regulation by ambient ph of the isopenicillin n synthase gene promoter.the isopenicillin n synthase (ipna) gene, encoding a key penicillin biosynthetic enzyme in aspergillus nidulans, represents a prototype of an alkaline-expressed gene. ipna is under ambient ph regulation, and its promoter (ipnap) contains binding sites for the zinc-finger transcription factor pacc. we show here that three of these sites, denoted ipna2, ipna3, and ipna4ab, are efficiently recognized by the protein in an isolated sequence context. single, double, and triple inactivation of these si ...19968910527
asm-1+, a neurospora crassa gene related to transcriptional regulators of fungal development.this report describes the identification, cloning, and molecular analysis of asm-1+ (ascospore maturation 1), the neurospora crassa homologue of the aspergillus nidulans stua (stunted a) gene. the asm-1+ gene is constitutively transcribed and encodes an abundant, nucleus-localized 68.5-kd protein. the protein product of asm-1+ (asm-1), contains a potential dna-binding motif present in related proteins from a. nidulans (stua), candida albicans (efgtf-1), and saccharomyces cerevisiae (phd1 and sok ...19968913744
identification, isolation and sequence of the aspergillus nidulans xlnc gene encoding the 34-kda xylanase.the xlnc gene encoding the 34-kda xylanase (x34) of aspergillus nidulans (an) has been cloned and sequenced, as has its corresponding cdna. xlnc contains nine introns and shows considerable similarity to the xyna and xylp xylanase-encoding genes of a. kawachii (ak) and penicillium chrysogenum (pc), respectively. analysis of xylanase production in an multicopy transformants showed elevated levels of x34 and increased total xylanase activity, but no elevated production of other xylanases. northern ...19968917072
molecular cloning of higher plant homologues of the high-affinity nitrate transporters of chlamydomonas reinhardtii and aspergillus nidulans.the crna nitrate transporter from aspergillus nidulans was identified as belonging to the major facilitator superfamily (mfs) of membrane transporters. degenerate oligonucleotides corresponding to the crna sequences at the locations of two conserved sequence motifs were designed and used in the polymerase chain reaction (pcr) to amplify related sequences from barley root poly(a)+ rna. a 130 bp cdna fragment with sequence similarities to crna was amplified and used as a probe to screen a barley r ...19968917103
20s cyclosome complex formation and proteolytic activity inhibited by the camp/pka pathway.the 20s cyclosome complex (also known as the anaphase-promoting complex) has ubiquitin ligase activity and is required for mitotic cyclin destruction and sister chromatid separation. the formation and activation of the 20s cyclosome complex is regulated by an unknown mechanism. here we show that cut4 (ref. 6) is an essential component of the cyclosome in fission yeast. cut4 shares sequence similarity with bime, a protein that regulates mitosis in aspergillus nidulans. mutations in cut4 result in ...19968918880
induction of beta-oxidation enzymes and microbody proliferation in aspergillus nidulans.aspergillus nidulans is able to grow on oleic acid as sole carbon source. characterization of the oleate-induced beta-oxidation pathway showed the presence of the two enzyme activities involved in the first step of this catabolic system: acyl-coa oxidase and acyl-coa dehydrogenase. after isopicnic centrifugation in a linear sucrose gradient, microbodies (peroxisomes) housing the beta-oxidation enzymes, isocitrate lyase and catalase were clearly resolved from the mitochondrial fraction, which con ...19968929280
sequence analysis and expression of the penicillium chrysogenum nitrate reductase encoding gene (niad).the nitrate reductase gene (niad) of the filamentous fungus penicillium chrysogenum encodes a protein of 864 amino acids. the derived protein sequence shows 78% and 72% sequence identity to the corresponding aspergillus niger and a. nidulans proteins, respectively. the coding region of the penicillium gene is interrupted by six small introns, as deduced by comparison with the niad sequences of a. niger and a. nidulans, whereby the positions of the introns are perfectly conserved between these th ...19968950182
the chsb gene of aspergillus nidulans is necessary for normal hyphal growth and development.the chsb gene from aspergillus nidulans encodes a class iii chitin synthase, an enzyme class found in filamentous fungi but not in yeast-like organisms. using a novel method, we isolated haploid segregants carrying a disrupted chsb allele from heterozygous diploid disruptants. the haploid disruptants grow as minute colonies that do not conidiate. hyphae from the disruptants have enlarged tips, a high degree of branching, and disorganized lateral walls. the mycelium is not deficient in chitin con ...19968953267
expression of human recombinant beta 2-microglobulin by aspergillus nidulans and its activity.the light chain of hla class i protein (beta 2m) has been expressed in aspergillus nidulans. the cdna of beta 2m was modified using the polymerase chain reaction to include overlapping extensions for its subsequent fusion into an aspergillus vector. this fusion resulted in beta 2m cdna being flanked by the aspergillus awamori glucoamylase promoter and the aspergillus niger glucoamylase terminator. expression of beta 2m was induced by the addition of starch to the culture medium. in preliminary m ...19968960907
aspergillus has distinct fatty acid synthases for primary and secondary metabolism.aspergillus nidulans contains two functionally distinct fatty acid synthases (fass): one required for primary fatty acid metabolism (fas) and the other required for secondary metabolism (sfas). fas mutants require long-chain fatty acids for growth, whereas sfas mutants grow normally but cannot synthesize sterigmatocystin (st), a carcinogenic secondary metabolite structurally and biosynthetically related to aflatoxin. sfas mutants regain the ability to synthesize st when provided with hexanoic ac ...19968962148
allotopic expression of mitochondrial atp synthase genes in nucleus of saccharomyces cerevisiae. 19968965711
hyma (hypha-like metulae), a new developmental mutant of aspergillus nidulans.asexual fruiting body development in aspergillus nidulans requires a precise spatial and temporal coordinated expression of many genes. insertional mutagenesis was used to isolate and characterize a new mutant of a. nidulans in which hyphal growth was slightly reduced and conidiophore development was specifically blocked at the metula stage. in contrast to the uninucleate metulae of the wild-type, in the mutant these structures were elongated, multinucleate and septate. further differentiation a ...19968969518
aspergillus fabm encodes an essential product that is related to poly(a)-binding proteins and activates development when overexpressed.overexpression of several different aspergillus nidulans developmental regulatory genes has been shown to cause inappropriate developmental activation and growth inhibition. we previously exploited this observation that induced development caused growth inhibition in designing a screen to identify other genes that could activate development when overexpressed. we identified 16 mutants in which induced expression of different random genomic dna sequences caused growth inhibition, accumulation of ...19968978035
analysis of cre1 binding sites in the trichoderma reesei cbh1 upstream region.a 1.5-kb xbai-sacii fragment containing the upstream region of the trichoderma reesei cellobiohydrolase i gene (cbh1) has been sequenced. the 1.5-kb fragment contains eight 6-bp sites having an identical or similar sequence to the consensus sequence for binding a catabolite repressor, aspergillus nidulans crea. results of binding assays with the maltose-binding protein::cre1(10-131) fusion protein (cre1 is a catabolite repressor of t. reesei) and the cbh1 upstream region revealed that a 504-bp x ...19968978090
characterization of a protease deficient strain of penicillium roqueforti generated by heterologous plasmid integration: potential use for protein production.a strain of penicillium roqueforti was transformed with a plasmid which confers resistance to phleomycin. stable transformants were selected. they all present a high resistance to the antibiotic. their proteolytic activity was tested. one transformant is a proteolytic deficient strain unable to degrade casein. it is characterized by a tandem integration of the transformant vector in one site of the genome. the extracellular proteins profile of the strain reveals the absence of a 43 kda polypepti ...19968987631
sequence-specific binding sites in the taka-amylase a g2 promoter for the crea repressor mediating carbon catabolite repression.the n-terminal part of the crea protein encompassing two zinc fingers was expressed in escherichia coli as a fusion protein with the maltose binding protein (male) of e. coli. our results show that crea binds to the promoter of the taa-g2 gene encoding taka-amylase a of aspergillus oryzae. dnase i footprinting experiments showed that crea bound to three sites with high affinity and to one site with low affinity within the first 401-bp region upstream of the transcription initiation site. all of ...19968987852
a novel transporter involved in cobalt uptake.cobalt is an essential component of a low molecular-mass nitrile hydratase (l-nhase) from rhodococcus rhodochrous j1. we have found a new gene, nhlf, in the dna region sandwiched between nhlba encoding l-nhase and amda encoding amidase, which are involved in the degradation of nitriles. the product of nhlf, nhlf, shows a significant sequence similarity with those of hoxn from alcaligenes eutrophus, hupn from bradyrhizobium japonicum, nixa from helicobacter pylori, and ureh from bacillus sp., whi ...19978990157
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
aspergillus nidulans stcl encodes a putative cytochrome p-450 monooxygenase required for bisfuran desaturation during aflatoxin/sterigmatocystin biosynthesis.the aspergillus nidulans stcl gene is predicted to encode a cytochrome p-450 monooxygenase and is located within a cluster of other genes that are required for synthesis of sterigmatocystin. inactivation of stcl resulted in strains that accumulate dihydrosterigmatocystin, a tetrahydrobisfuran containing molecule that is very similar to the unsaturated product of the wild-type pathway, sterigmatocystin. this observation led us to hypothesize that the a. nidulans sterigmatocystin biosynthetic path ...19978999832
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
the filamentous fungus aspergillus niger contains two "differentially regulated" trehalose-6-phosphate synthase-encoding genes, tpsa and tpsb.two genes encoding trehalose-6-phosphate synthase were cloned from aspergillus niger. tpsa was cloned using the saccharomyces cerevisiae ggs1/tps1 gene as a probe. it encodes a 517-amino acid polypeptide with 64-70% similarity to trehalose-6-phosphate synthase of s. cerevisiae, kluyveromyces lactis, and schizosaccharomyces pombe. its transcription occurs constitutively and is enhanced on carbon-derepressing carbon sources, coinciding with the presence of a crea-binding nucleotide motif in the 5' ...19979006911
a study of protein-water exchange through the off-resonance roesy experiment: application to the dna-binding domain of 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
the g2/m dna damage checkpoint inhibits mitosis through tyr15 phosphorylation of p34cdc2 in aspergillus is possible to cause g2 arrest in aspergillus nidulans by inactivating either p34cdc2 or nima. we therefore investigated the negative control of these two mitosis-promoting kinases after dna damage. dna damage caused rapid tyr15 phosphorylation of p34cdc2 and transient cell cycle arrest but had little effect on the activity of nima. dividing cells deficient in tyr15 phosphorylation of p34cdc2 were sensitive to both mms and uv irradiation and entered lethal premature mitosis with damaged dna. ...19979009279
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
expression of a constitutively active ca2+/calmodulin-dependent kinase in aspergillus nidulans spores prevents germination and entry into the cell cycle.the unique gene for ca2+/calmodulin-dependent protein kinase (camk) has been shown to be essential in aspergillus nidulans. disruption of the gene prevents entry of spores into the nuclear division cycle. here we show that expression of a constitutively active form of camk also prevents spores from entering the first s phase in response to a germinating stimulus. expression of the constitutively active kinase induces premature activation of nimecyclin b/nimxcdc2 in g0/g1. as nimxcdc2 is present ...19979013558
a prolactin-inducible t cell gene product is structurally similar to the aspergillus nidulans nuclear movement protein nudc.clone 15 (c15) was originally identified as a prl-inducible gene in activated t cells. sequence analysis of c15 revealed that the last 94 amino acids of c15 are 68% identical and 78% similar to the filamentous fungus aspergillus nidulans nuclear movement protein nudc. the identification of the mammalian (rat) c15 protein suggests that the carboxy-terminal nudc-like region has been conserved over evolution for an important structure and/or function. to determine whether c15 is functionally analog ...19979013770
proteolytic activation of rim1p, a positive regulator of yeast sporulation and invasive the yeast saccharomyces cerevisiae, rim1, 8, 9, or 13 mutations cause four phenotypes: poor growth at low temperature, altered colony morphology, inefficient sporulation due to reduced expression of the meiotic activator ime1, and, as shown here, defective invasive growth. in this report, we have determined the relationship between rim1 and the other genes, rim8, 9, and 13, in this group. we have analyzed production of epitope-tagged rim1p derivatives with ha epitopes at the n-terminus or in ...19979017390
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
the ynt1 gene encoding the nitrate transporter in the yeast hansenula polymorpha is clustered with genes yni1 and ynr1 encoding nitrite reductase and nitrate reductase, and its disruption causes inability to grow in nitrate.dna sequencing in the phage lambda ja13 isolated from a lambda embl3 hansenula polymorpha genomic dna library containing the nitrate reductase-(ynr1) and nitrite reductase-(yni1) encoding genes revealed an open reading frame (ynt1) of 1524 nucleotides encoding a putative protein of 508 amino acids with great similarity to the nitrate transporters from aspergillus nidulans and chlamydomonas reinhardtii. disruption of the chromosomal ynt1 copy resulted in incapacity to grow in nitrate and a signif ...19979020872
anaerobic crystallisation of an isopenicillin n synthase.fe(ii).substrate complex demonstrated by x-ray studies.isopenicillin n synthase (ipns) was cocrystallised with ferrous sulphate and its substrate, delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (aad-cys-val). vital to the successful procedure was the maintenance of a rigorously anaerobic environment. hanging-drop vapour-diffusion crystallisation experiments, using lithium sulphate as the precipitant produced three crystal forms. form i crystals, with a plate habit, diffracted x-rays to at least 0.11-nm resolution at the european synchrotron radia ...19969022704
the aspergillus nidulans genes chsa and chsd encode chitin synthases which have redundant functions in conidia formation [corrected and republished article originally appeared in mol gen genet 1996 jun; 251(4):442-50].we previously isolated three chitin synthase genes (chsa, chsb, and chsc) from aspergillus nidulans. in the present work, we describe the isolation and characterization of another chitin synthase gene, named chsd, from a. nidulans. its deduced amino acid sequence shows 56.7% and 55.9% amino acid identity, respectively, with cal1 of saccharomyces cerevisiae and chs3 of candida albicans. disruption of chsd caused no defect in cell growth or morphology during the asexual cycle and caused no decreas ...19979037115
identification of amdx, a new cys-2-his-2 (c2h2) zinc-finger gene involved in the regulation of the amds gene of aspergillus nidulans.the acetamidase-encoding amds gene of aspergillus nidulans has been shown to be controlled by multiple regulatory genes. a new gene, amdx, involved in amds regulation was identified during the characterization of a translocation affecting amds control. the amdx gene is predicted to encode a 1150-amino-acid polypeptide which contains two cys-2-his-2 (c2h2) zinc finger dna-binding motifs. insertional inactivation of amdx and the phenotypes of transformants containing multiple copies of the amdx ge ...19979044292
characterization of the ph signal transduction pathway gene pala of aspergillus nidulans and identification of possible homologs.we have cloned the pala gene of aspergillus nidulans, one of six genes participating in ambient ph signal transduction in a regulatory circuit mediating ph regulation of gene expression. the derived 798-residue pala protein is 29.4% identical over its entire length to a hypothetical protein from the nematode caenorhabditis elegans and also has possible yeast homologs.19979045850
genetic and molecular analysis of a trna(leu) missense suppressor of nudc3, a mutation that blocks nuclear migration in aspergillus nidulans.nudc encodes a protein of unknown biochemical function that is required for nuclear migration. in an attempt to define its function by identifying interacting proteins, a screen for extragenic suppressors of the temperature-sensitive nudc3 mutation was undertaken that identified nine snc genes. here we demonstrate that nudc3 has a missense mutation at amino acid 146 that causes leucine to be replaced by proline and that sncb69 encodes a mutant trna(leu) that corrects the mutation. the sncb69 mut ...19979055080
spectrophotometric determination of homogentisate using aspergillus nidulans homogentisate dioxygenase.the presence of homogentisic acid (hga) in urine is diagnostic for alkaptonuria, a classical example of a biochemical lesion resulting from a single gene trait. we describe here simple culture conditions which induce the synthesis of high levels of homogentisate dioxygenase activity in mycelia from the filamentous ascomycete aspergillus nidulans. crude enzyme preparations, showing an apparent km of 9 microm for homogentisate and an optimal ph of 6.5-7.0 are rather stable and highly specific for ...19979056215
salt sensitivity and arginase activity in aspergillus nidulans. 19979056996
aspergillus nidulans maintains short telomeres throughout development.we report the identification and cloning of the telomeres of the filamentous fungus,aspergillus nidulans. we have identified three classes of cloned chromosomal ends based on the telomere-associated sequences (tass) and demonstrated that the telomeric repeat sequence is ttaggg, identical to that found in vertebrates, including humans, and some lower eukaryotes. one category of telomere clones was found to contain internal, variant taaggg repeats. the a.nidulans telomeric tract length is striking ...19979060439
molecular regulation of penicillin biosynthesis in aspergillus (emericella) nidulans.the beta-lactam antibiotic penicillin is produced as end product by only some filamentous fungi, most notably by aspergillus nidulans and penicillium chrysogenum. the biosynthesis of this secondary metabolite is catalyzed by three enzymes which are encoded by the following three genes: acva (pcbab), ipna (pcbc) and aat (pende). the genes are organized into a gene cluster. in a. nidulans, several studies have indicated that the genes are controlled by a complex regulatory network. the wide-domain ...19979066103
the phenylacetic acid uptake system of aspergillus nidulans is under a crea-independent model of catabolic repression which seems to be mediated by acetyl-coa.the filamentous fungus aspergillus nidulans is able to grow on phenylacetic acid (phac) as the sole carbon source and has a highly specific phenylacetic acid transport system mediating the uptake of this aromatic compound. this transport system is also able to transport some phenoxyacetic acid (phoac), although less efficiently. maximal uptake rates were observed at 37 degrees c in 50 mm phosphate buffer (ph 7.0). under these conditions, uptake was linear for at least 1 minute, with k(m) values ...19979066765
isolation of aspergillus nidulans mutants that overcome brla-induced growth arrestthe aspergillus nidulans brla gene is a primary regulator of development-specific gene expression during conidiation. forced activation of brla in vegetative cells leads to inappropriate induction of conidiophore formation and causes growth to stop. in fact, when conidia containing a nutritionally inducible brla gene fusion are placed on inducing medium, they fail to germinate. we used this phenotype to select 174 mutants that continue growing following such forced brla activation. forty-six of ...19979073485
the glutamine ligand in the ferrous iron active site of isopenicillin n synthase of streptomyces jumonjinensis is not essential for catalysis.isopenicillin n synthase (ipns) is a non-heme ferrous iron dependent dioxygenase that catalyses the ring closure of delta-(l-alpha-aminoadipoyl)-l-cysteinyl-d-valine (acv) to isopenicillin n. we previously used site-directed mutagenesis to identify in the ipns of streptomyces jumonjinensis two histidines and one aspartic acid that are essential for activity. the recent crystal structure of the ipns of aspergillus nidulans establishes that these amino acids are iron ligands and reveals that the f ...19979089285
glutamine-330 is not essential for activity in isopenicillin n synthase from aspergillus nidulans.the non-heme ferrous dependent oxidase isopenicillin n synthase (ipns) catalyses the biosynthesis of isopenicillin n from a tripeptide substrate. the crystal structure of aspergillus nidulans ipns complexed to manganese reveals a six co-ordinate metal ligated by two water molecules and four protein ligands: his-214, his-270, asp-216 and gln-330 (the penultimate c-terminal residue). modification of gln-330 to ala or leu, or deletion of 2 or 6 residues from the c-terminus resulted in lowering of s ...19979089289
the role of gamma-tubulin in mitotic spindle formation and cell cycle progression in aspergillus nidulans.gamma-tubulin has been hypothesized to be essential for the nucleation of the assembly of mitotic spindle microtubules, but some recent results suggest that this may not be the case. to clarify the role of gamma-tubulin in microtubule assembly and cell-cycle progression, we have developed a novel variation of the gene disruption/heterokaryon rescue technique of aspergillus nidulans. we have used temperature-sensitive cell-cycle mutations to synchronize germlings carrying a gamma-tubulin disrupti ...19979092944
alkaptonuria: from humans to moulds and back. 19979097720
cloning and characterization of the aspergillus nidulans cysb gene encoding cysteine synthase.the cysb gene of a. nidulans was cloned by complementation of a cysb mutation. this is the first cloned eukaryotic genomic sequence coding for cysteine synthase. the gene contains one 71-bp intron and codes for a protein of 370 amino acids. its n-terminal region has characteristic features of transit peptides, suggesting mitochondrial localisation of the enzyme. the protein shows homology with bacterial and plant cysteine synthases among which it occupies a remote phylogenetic position and appar ...19979108143
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