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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
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
beta-lactams. 19958688626
tyrosine 495 is a key residue in the active site of galactose oxidase. 19958654695
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
the bgl1 gene of trichoderma reesei qm 9414 encodes an extracellular, cellulose-inducible beta-glucosidase involved in cellulase induction by sophorose.we have investigated the effect of disruption of the bgl1-(beta-glucosidase l-encoding) gene of trichoderma reesei on the formation of other beta-glucosidase activities and on the induction of cellulases. to this end the bgl1 locus was disrupted by insertion of the aspergillus nidulans amds (acetamidase-encoding) gene. the bgl1-disrupted strain did not produce the 75 kda extracellular beta-glucosidase on cellulose or lactose, but still formed beta-glucosidase activity on glucose, cellobiose, xyl ...19957476163
stcs, a putative p-450 monooxygenase, is required for the conversion of versicolorin a to sterigmatocystin in aspergillus nidulans.sterigmatocystin (st) and aflatoxin are carcinogenic end point metabolites derived from the same biochemical pathway, which is found in several aspergillus spp. recently, an st gene cluster, containing approximately 25 distinct genes that are each proposed to function specifically in st biosynthesis, has been identified in aspergillus nidulans. each of these structural genes is named stc (sterigmatocystin) followed by a consecutive letter of the alphabet. we have previously described stcu (forme ...19957486998
sepb: an aspergillus nidulans gene involved in chromosome segregation and the initiation of cytokinesis.in aspergillus nidulans conidia, cytokinesis (septation) is delayed until three rounds of nuclear division have been completed. this has permitted the identification of essential genes that are involved in the coordination of cytokinesis with nuclear division. conditional mutations in the sepb gene block septation but allow germinating spores to complete the first three rounds of nuclear division at restrictive temperature. sepb3 mutants demonstrate transient delays in m-phase, accumulate aneupl ...19957489714
insertion into aspergillus nidulans of functional udp-glcnac: alpha 3-d- mannoside beta-1,2-n-acetylglucosaminyl-transferase i, the enzyme catalysing the first committed step from oligomannose to hybrid and complex n-glycans.filamentous fungi are capable of secreting relatively large amounts of heterologous recombinant proteins. recombinant human glycoproteins expressed in this system, however, carry only carbohydrates of the oligomannose type limiting their potential use in humans. one approach to the problem is genetic engineering of the fungal host to permit production of complex and hybrid n-glycans. udp-glcnac:alpha 3-d-mannoside beta- 1,2-n-acetylglucosaminyltransferase i (gnt i) is essential for the conversio ...19957496151
substrate specificity of nine nad(+)-dependent alcohol dehydrogenases in aspergillus nidulans.in aspergillus nidulans three alcohol dehydrogenases (adhs) have been described. adhi is induced by ethanol and is the physiological enzyme of ethanol utilization, adhii has not been attributed a function but is repressed by ethanol. the alcr regulatory protein acts positively to induce adhi, and negatively in its control of adhii. adhiii is specifically induced by anaerobic stress. we have characterized the substrate specificity of these three enzymes by looking at their staining profile on pol ...19957496541
an extreme crea mutation in aspergillus nidulans has severe effects on d-glucose utilization.aspergillus nidulans wild-type and the extreme carbon catabolite derepressed mutant cread-30 were characterized with respect to enzyme activities, metabolite concentrations and polyol pools all related to glycolysis, after growth on d-glucose. in the cread-30 strain the enzymes hexokinase and fructose-6-phosphate reductase showed a two- and threefold increase in activity, respectively, whereas phosphofructokinase and pyruvate kinase activity decreased two- and threefold, respectively, in compari ...19957496542
molecular biological analysis of a bidirectional hydrogenase from cyanobacteria.an 8.9-kb segment with hydrogenase genes from the cyanobacterium anabaena variabilis has been cloned and sequenced. the sequences show homology to the methyl-viologen-reducing hydrogenases from archaebacteria and, even more striking, to the nad(+)-reducing enzymes from alcaligenes eutrophus and nocardia opaca as well as to the nadp(+)-dependent protein from desulfovibrio fructosovorans. the cluster from a. variabilis contains genes coding for both the hydrogenase heterodimer (hoxh and hoxy) and ...19957588754
post-transcriptional control and kinetic characterization of proline transport in germinating conidiospores of aspergillus nidulans.in the filamentous fungus aspergillus nidulans, l-proline uptake is mediated by the product of the prnb gene which codes for a member of a family of amino acid transporters found both in pro- and eukaryotes. regulation of prnb gene expression has previously been studied in great detail at the molecular level. however, no studies have addressed possible post-transcriptional controls or the kinetic characterisation of the prnb transporter. here we develop a rapid and efficient method for direct up ...19957590163
a lacz reporter fusion method for the genetic analysis of regulatory mutations in pathways of fungal secondary metabolism and its application to the aspergillus nidulans penicillin pathway.secondary metabolism, usually superfluous under laboratory conditions, is intrinsically elusive to genetic analysis of its regulation. we describe here a method of analyzing regulatory mutations affecting expression of secondary metabolic genes, with an aspergillus nidulans penicillin structural gene (ipna [encoding isopenicillin n-synthase]) as a model. the method is based on a targeted double integration of a lacz fusion reporter gene in a chromosome different from that containing the penicill ...19957592369
phanerochaete chrysosporium glyoxal oxidase is encoded by two allelic variants: structure, genomic organization, and heterologous expression of glx1 and glx2.a cdna clone (glx-2c) encoding glyoxal oxidase (glox) was isolated from a phanerochaete chrysosporium lambda gt11 library, and its nucleotide sequence was shown to be distinct from that of the previously described clone glx-1c (p. j. kersten and d. cullen, proc. natl. acad. sci. usa 90:7411-7413, 1993). genomic clones corresponding to both cdnas were also isolated and sequenced. overall nucleotide sequence identity was 98%, and the predicted proteins differed by a single residue: lys-308<==>thr- ...19957592374
a novel nitrite reductase gene from the cyanobacterium plectonema boryanum.the gene (nira) for nitrite reductase was cloned from the nonheterocystous, filamentous cyanobacterium plectonema boryanum. the predicted protein consists of 654 amino acids and has a calculated molecular weight of 72,135. the deduced amino acid sequence from positions 1 to 511 is strongly similar to the entire sequence of the ferredoxin-dependent nitrite reductases from other phototrophs, while the remainder of the protein is unique to the plectonema nitrite reductase. the c-terminal portion of ...19957592378
nucleotide sequence and characterization of the large mitochondrial rrna gene of penicillium urticae, and its comparison with those of other filamentous fungi.the nucleotide sequence of a large rrna gene and its flanking regions in cloned fragments of mitochondrial dna from a patulin producer, penicillium urticae nrrl2159a, was determined by dideoxy sequencing, and the 5' end and intron-exon border of the 1-rrna gene were determined by primer extension analysis and rna sequencing, respectively. in addition to the extensive sequence homology of the 3' end of the p. urticae mt 1-rrna gene with those of aspergillus nidulans and neurospora crassa, the p. ...19957592555
the positively acting amda gene of aspergillus nidulans encodes a protein with two c2h2 zinc-finger motifs.semi-dominant mutations in the amda gene lead to elevated expression of the gene encoding acetamidase, amds. these mutations also cause constitutive expression of the acetate-inducible gene, acia. in the amds 5' regulatory region, two cis-acting mutations, amdl66 and amdl666, have been isolated which specifically affect amda activation of amds. these mutations are a duplication and a triplication of an 18 bp ga-rich sequence, thought to define the amda site of action within the amds promoter reg ...19957596297
a single amino acid change in a pathway-specific transcription factor results in differing degrees of constitutivity, hyperinducibility and derepression of several structural genes.unyc462 is a gain-of-function mutation in the purine catabolism positive regulatory gene of aspergillus nidulans. this allele leads to a constitutive, hyperinducible and derepressed expression of a least three genes controlled by uay, and this occurs at different levels depending on the target gene. the uayc462 allele was mapped physically in relation to known loss-of-function alleles and sequenced. uayc462 is a one-base change in codon 222, resulting in a serine to leucine change. we propose th ...19957602582
nudf, a nuclear migration gene in aspergillus nidulans, is similar to the human lis-1 gene required for neuronal migration.during a study of the genetics of nuclear migration in the filamentous fungus aspergillus nidulans, we cloned a gene, nudf, which is required for nuclear migration during vegetative growth as well as development. the nudf protein level is controlled by another protein nudc, and extra copies of the nudf gene can suppress the nudc3 mutation. nudf encodes a protein with 42% sequence identity to the human lis-1 (miller-dieker lissencephaly-1) gene, which is required for proper neuronal migration dur ...19957612965
aspergillus nidulans mutants affected in acetate metabolism isolated as lipid nonutilizers.interest in extracellular fungal lipases has increased mainly because of their industrial applications. however, no studies have been done on a genetically well characterized filamentous fungus like aspergillus nidulans. here we show that a. nidulans produces an extracellular lipase when grown in solid or liquid cultures containing lipids as carbon source. this lipase is glucose-repressed in a crea-independent fashion. seven mutants isolated by their inability to utilize lipids as sole carbon so ...19957614370
niaa, the structural nitrate reductase gene of phytophthora infestans: isolation, characterization and expression analysis in aspergillus nidulans.the nitrate reductase (nr) gene niaa of the oomycete phytophthora infestans was selected from a gene library by heterologous hybridization. niaa occurs as a single-copy gene ant its expression is regulated by the nitrogen source. the nucleotide sequence of niaa was determined and comparison of the deduced amino-acid sequence of 902 residues with nrs of higher fungi and plants revealed a significant homology, particularly within the three cofactor-binding domains for molybdenum, heme and fad. the ...19957614559
malvolio, the drosophila homologue of mouse nramp-1 (bcg), is expressed in macrophages and in the nervous system and is required for normal taste behaviour.we report the sequence, expression pattern and mutant phenotype of malvolio (mvl), the drosophila homologue of mammalian natural resistance-associated macrophage proteins (nramps). in the mouse, this novel transporter is encoded by bcg, a dominant gene that confers natural resistance to intracellular parasites. mvl was identified in a screen for mutants that affect taste behaviour. we show that loss-of-function as well as insertional mutants in mvl display defects in taste behaviour with no alte ...19957621816
activation of the aspergillus pacc transcription factor in response to alkaline ambient ph requires proteolysis of the carboxy-terminal moiety.extremes of ph are an occupational hazard for many microorganisms. in addition to efficient ph homeostasis, survival effectively requires a regulatory system tailoring the syntheses of molecules functioning beyond the cell boundaries (permeases, secreted enzymes, and exported metabolites) to the ph of the growth environment. our previous work established that the zinc finger pacc transcription factor mediates such ph regulation in the fungus aspergillus nidulans in response to a signal provided ...19957628696
sequence and structure of penicillium chrysogenum phog, homologous to an acid phosphatase-encoding gene of aspergillus nidulans.a penicillium chrysogenum (pc) gene (phog), homologous to an aspergillus nidulans (an) gene which confers phosphate-non-repressible acid phosphatase (apase) activity, has been cloned and sequenced. the 2.9-kb genomic sequence corresponds to two orfs of 149 and 1630 bp encoding a protein of 593 amino acids (aa). as verified by cdna sequencing, the coding region is interrupted by an 85-bp intron. the deduced aa sequence of phog reveals 61% aa identity to the translated long orf of the an apase-enc ...19957628710
isolation of a functional homolog of the cell cycle-specific nima protein kinase of aspergillus nidulans and functional analysis of conserved residues.to investigate the degree of conservation of the cell cycle-specific nima protein kinase of aspergillus nidulans, and to help direct its functional analysis, we cloned a homolog (designated nim-1) from neurospora crassa. over the catalytic domain nim-1 is 75% identical to nima, but overall the identity drops to 52%. nim-1 was able to functionally complement nima5 in a. nidulans. mutational analysis of potential activating phosphorylation sites found in nima, nim-1, and related protein kinases wa ...19957629122
the basal level of transcription of the alc genes in the ethanol regulon in aspergillus nidulans is controlled both by the specific transactivator alcr and the general carbon catabolite repressor crea.in the a. nidulans ethanol utilization pathway, specific induction is mediated by the transactivator alcr which is subject to strong positive autogenous regulation and activates the transcription of the two structural genes alca and alda. carbon catabolite repression is mediated by crea which represses directly the transacting gene alcr and the two structural genes. we show here that the basal expression of the alcr and alca genes is also controlled by the two regulatory circuits, positively by ...19957635218
effects of leader sequences upon the heterologous expression of restrictocin in aspergillus nidulans and aspergillus niger.the effects of altered leader sequences on the secretion and localization of restrictiocin expression in aspergillus nidulans and aspergillus niger were investigated. the region encoding the leader sequence of the aspergillus restrictus restrictocin (res) gene was altered and variants were expressed under the glucoamylase (glaa) promoter in a. nidulans and a. niger. the entire restrictocin leader sequence was replaced by the glaa leader sequence in one variant. in another, the signal sequence of ...19957641142
structure, organization and promoter expression of the actin-encoding gene in trichoderma reesei.the single gene encoding actin (act) in the cellulolytic filamentous fungus trichoderma reesei (tr) has been isolated and characterized. the gene contains five introns located in identical positions when compared to the putative ancestral actin genes (act) present in thermomyces lanuginosus and aspergillus nidulans. the 5' untranslated region (utr) of the gene contains a tata-like sequence (taata), a c + t-rich region and a potential ccaat motif. this region was used as a homologous promoter to ...19957642121
carbon source-dependent regulation of the acetyl-coenzyme a synthetase-encoding gene acs1 from saccharomyces cerevisiae.the yeast acs1 gene, encoding acetyl-coenzyme a synthetase (acs), was cloned using colony hybridization and a faca probe from aspergillus nidulans. the complete sequence of 1.5 kb of the acs1 upstream region was determined. northern hybridization revealed a strong depression of acs1 transcripts in a strain grown on the nonfermentable carbon sources, acetate or ethanol. in contrast to a previous report, delta acs1 null mutants did not exhibit a growth defect on acetate medium. indeed, enzyme assa ...19957642141
sterigmatocystin biosynthesis in aspergillus nidulans requires a novel type i polyketide synthase.a filamentous fungus, aspergillus nidulans, produces the carcinogenic mycotoxin sterigmatocystin (st), which is a polyketide-derived secondary metabolite. a gene (pksst) encoding the st polyketide synthase (pksst) in a. nidulans was cloned, sequenced, and characterized. large induced deletion mutants, which did not make st or any st intermediates, were used to identify genes associated with st biosynthesis. among the transcripts detected within the deletion region, which showed developmental exp ...19957642507
dewa encodes a fungal hydrophobin component of the aspergillus spore wall.an anonymous cdna clone, pcan4, was shown previously to correspond to an mrna that accumulates preferentially during asexual sporulation of the filamentous fungus aspergillus nidulans. the peptide encoded by pcan4 is a fungal hydrophobin, a group of small, hydrophobic cell wall proteins. when the can4 gene was disrupted, conidia and conidiophores appeared to be normal, but sporulating colonies wetted more rapidly with detergent solutions than did the wild type. we renamed can4 dewa for the deter ...19957651135
the aspergillus uvsh gene encodes a product homologous to yeast rad18 and neurospora uvs-2.the uvsh dna repair gene of aspergillus nidulans has been cloned by complementation of the uvsh77 mutation with a cosmid library containing genomic dna inserts from a wild-type strain. methylmethane sulfonate (mms)-resistant transformants were obtained on medium containing 0.01% mms, to which uvsh mutants exhibit high sensitivity. retransformation of uvsh77 mutants with the rescued cosmids from the mms-resistant transformants resulted in restoration of both uv and mms resistance to wild-type lev ...19957651340
the fusarium solani gene encoding kievitone hydratase, a secreted enzyme that catalyzes detoxification of a bean phytoalexin.among the antimicrobial phytoalexins produced by phaseolus vulgaris (french bean) is the prenylated isoflavonoid, kievitone. the bean pathogen, fusarium solani f. sp. phaseoli, secretes a glycoenzyme, kievitone hydratase (ec 4.2.1.95), which catalyzes conversion of kievitone to a less toxic metabolite. among f. solani strains, those that are highly virulent to p. vulgaris also produce kievitone hydratase constitutively, suggesting that the enzyme is a virulence factor. based on the n-terminal am ...19957655061
quantitation of oligohistidine fusion proteins using 63ni2+ chelation. 19957659532
genetic nomenclature guide. aspergillus nidulans. 19957660460
crystallization and preliminary x-ray diffraction studies on recombinant isopenicillin n synthase from aspergillus nidulans.recombinant aspergillus nidulans isopenicillin n synthase was purified from an escherichia coli expression system. the apoenzyme in the presence of saturating concentrations of mncl2 could be crystallized by either macro- or microseeding, using the hanging drop vapor diffusion technique with polyethylene glycol 8000 as precipitant. the crystals (0.5-1.0 mm overall dimensions) diffract x-rays to at least 2.0 a resolution at synchrotrons and belong to space group p212121 with unit cell dimensions ...19957663335
molecular cloning and heterologous expression of the gene encoding dihydrogeodin oxidase, a multicopper blue enzyme from aspergillus terreus.aspergillus terreus dihydrogeodin oxidase (dhgo) is an enzyme catalyzing the stereospecific phenol oxidative coupling reaction converting dihydrogeodin to (+)- geodin. we previously reported the purification of dhgo from a. terreus and raised polyclonal antibody against dhgo. from the first cdna library constructed in lambda gt11 using mrna from 3-day-old mycelium of a. terreus, four clones were identified using anti-dhgo antibody, but all contained partial cdna inserts around 280 base pairs. th ...19957665560
phylogenetic relationships of five species of aspergillus and related taxa as deduced by comparison of sequences of small subunit ribosomal rna.the nucleotide sequences of the genes encoding the 18s rrna of aspergillus flavus, a. nidulans, a. terreus and a. niger were elucidated and aligned to the sequences of a. fumigatus. in addition, the 18s rrna sequences of the v4-v9 region of morphologically similar filamentous fungi, e.g. penicillium chrysogenum, p. marneffei and paecilomyces variotii, were elucidated. phylogenetic analysis and comparison showed a very close intergeneric relationship of the genus aspergillus to species of the gen ...19957666299
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
salt sensitivity and arginine toxicity in aspergillus nidulans. 19957538946
copper-induced changes in the urea uptake and urease activity in the cyanobacteria anabaena doliolum and anacystis nidulans: interaction with sulphur containing amino acids.copper-induced changes in the urea uptake and urease activity have been investigated in the cyanobacteria anabaena doliolum and anacystis nidulans. copper, at and above 5 mumol/l concentration, inhibited urea uptake and urease activity systems in both the cyanobacteria in a concentration dependent manner. however, the urea uptake and urease activity systems in a. nidulans appeared slightly more tolerant to copper than than of a. doliolum. the inhibitory effect of copper on urea uptake and urease ...19957546344
analysis of a mycotoxin gene cluster in aspergillus nidulans.aspergillus nidulans has functioned as a model system for the study of fungal genetics since the 1950s. application of methodologies ranging from mendelian genetics to the most sophisticated molecular biological techniques have resulted in a detailed understanding of genes and pathways involved in primary metabolism, secondary metabolism and development in a. nidulans. we have taken advantage of this background in developing a. nidulans as a genetic system to study the molecular mechanisms regul ...19957546572
cloning and nucleotide sequence of the calmodulin-encoding gene (cmda) from aspergillus oryzae.a cdna and genomic gene encoding calmodulin were isolated from aspergillus oryzae using a part of the calmodulin gene from a. nidulans as a hybridization probe. the gene was in a 3.4-kb sphi fragment and southern-blot analysis of genomic dna suggested the existence of a single copy of the calmodulin gene in a. oryzae. the nucleotide sequence analysis showed that the gene consists of five introns and six exons. although the nucleotide sequence homology with that of a. nidulans was not so high (68 ...19957549095
a pre-induction sporulation gene from aspergillus nidulans.asexual sporulation in aspergillus nidulans is an inducible developmental process controlled by genes that act before and after the inductive stimulus is applied. genes that act before induction (pre-induction genes) potentially represent functions required for response to induction. this report describes the isolation and characterization of the acob pre-induction gene which was cloned by complementation of a thermosensitive aconidial mutant followed by gene rescue. genetic analysis and gene di ...19957551046
the aspergillus parasiticus polyketide synthase gene pksa, a homolog of aspergillus nidulans wa, is required for aflatoxin b1 biosynthesis.aflatoxins comprise a group of polyketide-derived carcinogenic mycotoxins produced by aspergillus parasiticus and aspergillus flavus. by transformation with a disruption construct, pxx, we disrupted the aflatoxin pathway in a. parasiticus srrc 2043, resulting in the inability of this strain to produce aflatoxin intermediates as well as a major yellow pigment in the transformants. the disruption was attributed to a single-crossover, homologous integration event between pxx and the recipient a. pa ...19957565588
the intergenic region between the divergently transcribed niia and niad genes of aspergillus nidulans contains multiple nira binding sites which act bidirectionally.the niad and niia genes of aspergillus nidulans, which code, respectively, for nitrate and nitrite reductases, are divergently transcribed, and their atgs are separated by 1,200 bp. the genes are under the control of the positively acting nira transcription factor, which mediates nitrate induction. the dna binding domain of nira was expressed as a fusion protein with the glutathione s-transferase of schistosoma japonicum. gel shift and footprint experiments have shown that in the intergenic regi ...19957565720
fungal metabolic model for human type i hereditary tyrosinaemia.type i hereditary tyrosinaemia (ht1) is a severe human inborn disease resulting from loss of fumaryl-acetoacetate hydrolase (fah). homozygous disruption of the gene encoding fah in mice causes neonatal lethality, seriously limiting use of this animal as a model. we report here that faha, the gene encoding fah in the fungus aspergillus nidulans, encodes a polypeptide showing 47.1% identity to its human homologue, faha disruption results in secretion of succinylacetone (a diagnostic compound for h ...19957568087
characterization and localization of the cytoplasmic dynein heavy chain in aspergillus nidulans.migration of nuclei throughout the mycelium is essential for the growth and differentiation of filamentous fungi. in aspergillus nidulans, the nuda gene, which is involved in nuclear migration, encodes a cytoplasmic dynein heavy chain. in this paper we use antibodies to characterize the aspergillus cytoplasmic dynein heavy chain (acdhc) and to show that the acdhc is concentrated at the growing tip of the fungal mycelium. we demonstrate that four temperature-sensitive mutations in the nuda gene r ...19957568239
does gene palb regulate the transcription or the post-translational modification of pi-repressible phosphatases of aspergillus nidulans?when grown on low-pi medium, the chaa1 pabaa1 palb7 mutant of aspergillus nidulans excretes an acid phosphatase with steady-state kinetic properties, temperature sensitivity and electrophoretic mobility different from those of the enzyme excreted by the pabaa1 strain. the enzyme excreted by the pabaa1 strain at ph 6.5 showed pnp-p activity with negative cooperativity (k0.5 = 0.87 +/- 0.06 mm, n = 0.68 +/- 0.03) whereas the enzyme excreted by the chaa1 pabaa1 palb7 mutant showed michaelian kineti ...19957581026
aspergillus fumigatus antigens.cytosolic fractions of mycelial extracts from aspergillus nidulans, a. flavus, and three different isolates of a. fumigatus, grown to stationary phase in czapek-dox-aoac medium, were tested by immunoblotting for the presence of antigens reactive to 80 serum samples from aspergilloma patients. fifty control serum samples were used to determine the specificity of the reactions. in the a. fumigatus cytosolic fraction a group of four main antigenic bands (p90, p60, p40 and p37) was consistently reco ...19957582030
signaling of ambient ph in aspergillus involves a cysteine protease.in aspergillus nidulans, the regulation of gene expression in response to changes in ambient ph is mediated by the pacc zinc finger transcriptional regulator. at alkaline ambient ph, pacc is proteolytically processed to a functional form serving as an activator of alkaline-expressed genes and a repressor of acid-expressed genes. this activation of pacc occurs in response to a signal mediated by the products of the pal genes. thus, the products of the pala, -b, -c, -f, -h, and -i genes constitute ...19957499363
structural analysis of pks1, a polyketide synthase gene involved in melanin biosynthesis in colletotrichum lagenarium.albino mutants (pks-) of colletotrichum lagenarium form nonmelanized appressoria and possess little penetrating ability on the host plant. the defect in albino mutant 79215 (pks-) is considered to lie in pentaketide biosynthesis and/or pentaketide cyclization during melanin biosynthesis. the cosmid pac7, carrying the pks1 gene, when transformed into the albino mutant restores the wild-type melanin phenotype. we have determine the dna sequence and the transcriptional organization of the pks1 gene ...19957500937
two group i introns with a c.g basepair at the 5' splice-site instead of the very highly conserved u.g basepair: is selection post-translational?in virtually all of the 200 group i introns sequenced thus far, the specificity of 5' splice-site cleavage is determined by a basepair between a uracil base at the end of the 5' exon and a guanine in an intron guide sequence which pairs with the nucleotides flanking the splice-site. it has been reported that two introns in the cytochrome oxidase subunit i gene of aspergillus nidulans and podospora anserina are exceptions to this rule and have a c.g basepair in this position. we have confirmed th ...19957501471
sequence around the 159 degree region of the bacillus subtilis genome: the pksx locus spans 33.6 kb.the nucleotide sequence of 20 kb contiguous to the pksx locus of bacillus subtilis was determined. six orfs were recognized, one of which extended for 13,341 nucleotides. their predicted products have significant similarities to proteins with known functions involved in the synthesis of polypeptides and polyketides or in fatty acid metabolism. at the nucleotide level, three regions with a high level of sequence identity (49-54%) to the aspergillus nidulans wa gene, responsible for the synthesis ...19957704258
identification of developmental regulatory genes in aspergillus nidulans by overexpression.overexpression of several aspergillus nidulans developmental regulatory genes has been shown to cause growth inhibition and development at inappropriate times. we set out to identify previously unknown developmental regulators by constructing a nutritionally inducible a. nidulans expression library containing small, random genomic dna fragments inserted next to the alca promoter [alca(p)] in an a. nidulans transformation vector. among 20,000 transformants containing random alca(p) genomic dna fu ...19957713416
genetic and molecular characterization of a gene encoding a wide specificity purine permease of aspergillus nidulans reveals a novel family of transporters conserved in prokaryotes and eukaryotes.in aspergillus nidulans, loss-of-function mutations in the uapa and azga genes, encoding the major uric acid-xanthine and hypoxanthine-adenine-guanine permeases, respectively, result in impaired utilization of these purines as sole nitrogen sources. the residual growth of the mutant strains is due to the activity of a broad specificity purine permease. we have identified uapc, the gene coding for this third permease through the isolation of both gain-of-function and loss-of-function mutations. u ...19957721763
the sequence and binding specificity of uay, the specific regulator of the purine utilization pathway in aspergillus nidulans, suggest an evolutionary relationship with the ppr1 protein of saccharomyces cerevisiae.the uay gene codes for a transcriptional activator mediating the induction of a number of unlinked genes involved in purine utilization in aspergillus nidulans. here we present the complete genomic and cdna nucleotide sequence of this gene. the gene contains two introns. the derived polypeptide of 1060 residues contains a typical zinc binuclear cluster domain and shows a number of similarities with the ppr1 regulatory gene of saccharomyces cerevisiae. these similarities are most striking in the ...19957729421
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 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
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
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
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 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 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
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
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
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