PMID(sorted ascending)
sequence and functional analysis of the positively acting regulatory gene amdr from aspergillus nidulans.the positively acting regulatory gene amdr of aspergillus nidulans coordinately regulates the expression of five structural genes involved in the catabolism of certain amides (amds), omega amino acids (gata and gaba), and lactams (lama and lamb) in the presence of omega amino acid inducers. analysis of the amdr gene showed that it contains three small introns, heterogeneous 5' and 3' transcription sites, and multiple aug codons prior to the major aug initiator. the predicted amdr protein sequenc ...19902188110
isozyme polymorphism of endo-beta-1,4-glucanase in aspergillus electrophoretic survey of the natural populations of aspergillus nidulans, the a. nidulans group, and various species belonging to the genus aspergillus from diverse geographical areas of india was carried out to determine the isozyme polymorphism of endoglucanase. the data revealed the presence of three forms of endoglucanase designated eg i, eg ii, and eg iii. in some isolates, eg i and eg ii were present separately; in others, instead of two separate bands, one thick band was detected, whi ...19902188645
complementation of the aspergillus nidulans arg b1 mutation by ornithine transcarbamylase cdna from rat aspergillus nidulans strain which is deficient in ornithine transcarbamylase due to the arg b1 mutation was transformed with a plasmid containing the ornithine transcarbamylase cdna from rat liver under the control of the amd s promoter. stable transformants were obtained by selection on arginine free medium indicating complementation of the arg b mutation. proof of expression of the rat enzyme in transformants was obtained by immunoprecipitation of all ornithine transcarbamylase activity fro ...19902189407
sequence and molecular structure of the aspergillus nidulans ya (laccase i) gene. 19902192364
nucleotide sequences of the meta-cleavage pathway enzymes 2-hydroxymuconic semialdehyde dehydrogenase and 2-hydroxymuconic semialdehyde hydrolase from pseudomonas cf600.the nucleotide sequence of a 2493 base pair (bp) region, spanning the coding regions for the meta-cleavage pathway enzymes 2-hydroxymuconic semialdehyde dehydrogenase (hmsd) and 2-hydroxymuconic semialdehyde hydrolase (hmsh), was determined. the deduced protein sequence for hmsd is 486 amino acid residues long with an mr of 51,682. hmsd has homology with a number of aldehyde dehydrogenases from various eukaryotic sources. the deduced protein sequence for hmsh is 283 amino acids long with an mr o ...19902194577
gamma-tubulin is a component of the spindle pole body that is essential for microtubule function in aspergillus nidulans.we have recently discovered that the mipa gene of a. nidulans encodes gamma-tubulin, a new member of the tubulin superfamily. to determine the function of gamma-tubulin in vivo, we have created a mutation in the mipa gene by integrative transformation, maintained the mutation in a heterokaryon, and determined the phenotype of the mutation in spores produced by the heterokaryon. the mutation is lethal and recessive. it strongly inhibits nuclear division, less strongly inhibits nuclear migration, ...19902194669
increasing tubc beta-tubulin synthesis by placing it under the control of a bena beta-tubulin upstream sequence causes a reduction in bena beta-tubulin level but has no effect on microtubule function.we have constructed a chimeric beta-tubulin gene that places the structural gene for the tubc beta-tubulin of aspergillus nidulans under the control of the bena beta-tubulin promoter. introduction of either this chimeric gene or a second wild-type bena gene into a benomyl-resistant bena22 strain causes it to become benomyl sensitive, indicating that the introduced genes are functional. analysis of the tubulin proteins synthesized in bena22 strains into which a second wild-type bena beta-tubulin ...19902194681
developmental repression of growth and gene expression in aspergillus.asexual reproductive development can be initiated in aspergillus nidulans in the presence of excess nutrients through artificial induction of the developmental regulatory genes brla or abaa by fusing the genes to the promoter from the alcohol dehydrogenase i gene (alca) and culturing cells in the presence of an inducing alcohol. artificially induced development completely inhibits growth and represses expression of the endogenous alca gene and the coordinately controlled aldehyde dehydrogenase g ...19902196567
frequency of spontaneous and induced recessive mutations in a diploid strain of aspergillus nidulans.the spontaneous and uv-induced frequencies of recessive mutations have been studied in a diploid strain of aspergillus nidulans, by the p-fluoro-phenylalanine (fpa) and 8-azaguanine (8-aza) resistance tests, on either resting or germinating conidia. observed frequencies are in the order of magnitude of those expected, which have been calculated considering the observed mutation frequencies in the haploid strain as well as the mitotic recombination frequencies. we also review some papers which cl ...19902197553
cloning of the dna repair gene, uvsf, by transformation of aspergillus a first step in the cloning of the dna repair gene uvsf of aspergillus nidulans, uvsf pyrg double mutant strains were transformed with a genomic library which carried the complementing neurospora pyr-4 gene in the vector. rare pyr+ uvs+ cotransformants were obtained on media lacking pyrimidines, overlayed with mms (methyl-methane sulfonate) to which uvsf is hypersensitive. among mms-resistant transformants, southerns revealed two types which showed single bands of different sizes when bglii-d ...19902199316
characterization and expression of the unique calmodulin gene of aspergillus nidulans.complete cdna and genomic clones for the unique calmodulin (cam) gene of the filamentous fungus aspergillus nidulans have been isolated and characterized. the gene contains five introns, of which three are at unique positions relative to other cam genes. the a. nidulans cam gene is transcribed as a single, 0.85-kilobase mrna species that encodes a predicted protein 84% identical (93% similar if conservative changes are considered) to vertebrate cam. the complete cdna was ligated into a lambda pl ...19902199442
the molecular cloning and identification of a gene product specifically required for nuclear movement in aspergillus nidulans.a temperature-sensitive mutation in the nudc gene (nudc3) of aspergillus nidulans specifically prevents the microtubule-based movement of nuclei in this organism at the restrictive temperature. the mutation does not affect short term growth, nuclear division, or the movement of other subcellular organelles. immunofluorescence analysis of cells blocked at the restrictive temperature, using antitubulin antibodies, shows that the inability of nuclei to move under these conditions is not related to ...19902199460
purification and properties of nadp(+)-dependent glycerol dehydrogenases from aspergillus nidulans and a. niger.glycerol dehydrogenase, nadp(+)-specific (ec, was purified from mycelium of aspergillus nidulans and aspergillus niger using different purification procedures. both enzymes had an mr of approximately 38,000 and were immunologically cross-reactive, but had different amino acid compositions and isoelectric points. for both enzymes, the substrate specificity was limited to glycerol and erythritol for the oxidative reaction and to dihydroxyacetone (dha), diacetyl, methylglyoxal, erythrose ...19902200840
an inversion truncating the crea gene of aspergillus nidulans results in carbon catabolite derepression.the cread-30 mutation leading to carbon catabolite derepression in aspergillus nidulans is a pericentric inversion, having one breakpoint within the crea gene on the left arm of chromosome i and the other breakpoint between bing and ya on the right arm. the left-arm breakpoint alters the crea transcript. the likelihood that the inversion truncates crea centrally strengthens a previous proposal that derepression is the phenotype of loss-of-function mutations in crea.19902201871
p-fluoro-phenylalanine resistance in aspergillus nidulans diploid cells: evidence that dominant, lethal mutations are unexpectedly large number of p-fluoro-phenylalanine (fpa)-resistant mutants have been recovered after uv-irradiation of wild type diploid conidia of aspergillus nidulans. at least five different classes of mutants, possibly corresponding to five different loci, have been identified. two of them may be the dominant loci which have already been described but the others (a minimum of three loci) are completely different. mutations in these loci confer high level fpa resistance in the heterozygou ...19902202526
on the validation of the system of aspergillus for testing environmental aneugens. 19902203009
isolation and characterisation of the crna-niia-niad gene cluster for nitrate assimilation in aspergillus nidulans.genomic clones containing the entire crna-niia-niad gene cluster of aspergillus nidulans have been isolated, and the structures of the niia and niad genes have been determined by nucleotide sequence analysis. this gene cluster is required for the assimilation of nitrate in a. nidulans, and the three genes encode a product required for nitrate uptake and the enzymes, nitrite reductase and nitrate reductase, respectively. the putative coding sequences, as deduced by comparison to cdna clones of bo ...19902205530
screening method for large numbers of dye-adsorbents for enzyme purification.a method is described by means of which 96 different dye-adsorbents can be tested simultaneously for their ability to bind enzymes and to test their biospecific elution. small amounts of cell-free extract are applied to dye-adsorbents which are packed in a 96-well transplate cartridge. after biospecific elution, the amount of the eluted enzyme is tested in a microtitre plate assay. the method is illustrated by the purification of glycerol dehydrogenase (e.c., 6-phosphogluconate dehydro ...19902205614
a mutation which modifies the activity of a translational suppressor in aspergillus nidulans.a third type of translational fidelity mutation has been induced in aspergillus nidulans. the new mutation enhances growth, in suppressing conditions, of a strain containing suppressor suac109 and antisuppressor asud14 and is called alob8 for its allosuppressor activity. compared with the progenitor strain (asud14, suac109), ribosomes from the new mutant (alob8, asud14, suac109) increase misincorporation of leucine in a poly(u)-dependent homologous cell-free assay. the misreading level is mainta ...19902207157
isolation and molecular characterization of the aspergillus nidulans wa gene.the walls of aspergillus nidulans conidia contain a green pigment that protects the spores from damage by ultraviolet light. at least two genes, wa and ya, are required for pigment synthesis: ya mutants produce yellow spores, wa mutants produce white spores, and wa mutations are epistatic to ya mutations. we cloned wa by genetic complementation of the wa3 mutation with a cosmid library containing nuclear dna inserts from the wild-type strain. the wa locus was mapped to an 8.5-10.5-kilobase regio ...19902227390
chromatography and generation of specific antisera to synthetic peptides from a protective boophilus microplus antigen.four oligopeptides corresponding to predicted antigenic regions of the protective bm86 glycoprotein of the cattle tick boophilus microplus were synthesized and purified. three were conjugated to carrier proteins and antisera raised in rabbits and cows. all elicited antipeptide antibodies that recognized bm86 and recombinant derived products in western blots; however, only one produced antiserum capable of recognizing native bm86 in an indirect immunofluorescence assay. ticks fed in vitro on this ...19902229227
characterization of a glycerol kinase mutant of aspergillus niger.a glycerol-kinase-deficient mutant of aspergillus niger was isolated. genetic analysis revealed that the mutation is located on linkage group vi. the phenotype of this mutant differed from that of a glycerol kinase mutant of aspergillus nidulans in its ability to utilize dihydroxyacetone (dha). the weak growth on glycerol of the a. niger glycerol kinase mutant showed that glycerol phosphorylation is an important step in glycerol catabolism. the mutant could still grow normally on dha because of ...19902230717
nucleotide and amino acid sequences of the conidium-specific spoc1-c1d gene from aspergillus nidulans. 19902243803
the identification of mutations in aspergillus nidulans that lead to increased levels of adhii.there are at least three alcohol dehydrogenases in aspergillus nidulans. adhii has been observed in polyacrylamide gels stained for adh activity but, unlike adhi and adhiii, no physiological function has been attributed to it. this paper describes mutations that have been isolated from strains carrying a deletion in the structural gene for adhi (alca) and its adjacent positively-acting regulatory gene (alcr) that restore some ability to utilise ethanol as a carbon source. the mutations map at th ...19902245474
light is required for conidiation in aspergillus nidulans.light is necessary for asexual sporulation in aspergillus nidulans but will elicit conidiation only if irradiation occurs during a critical period of development. we show that conidiation is induced by red light and suppressed by an immediate shift to far red light. conidiation-specific gene functions switch from light-independent to light-dependent activities coincident with the expression of brla, a regulator of conidiophore development. we also show that light dependence is abolished by a mut ...19902253875
nitrogen regulation in aspergillus: are two fingers better than one?the area gene, mediating nitrogen metabolite repression in aspergillus nidulans, encodes a positive-acting regulatory protein with a single putative dna-binding 'zinc finger' which is remarkably similar to the two 'zinc fingers' of the major regulatory protein of vertebrate erythroid cells (gf-1/eryf1/nf-e1). the area-300 mutation alters the specificity of gene activation in that it elevates expression of certain structural genes whilst reducing expression of certain others. it is an 'in-frame' ...19902253884
purification, cloning, and primary structure of an enantiomer-selective amidase from brevibacterium sp. strain r312: structural evidence for genetic coupling with nitrile enantiomer-selective amidase active on several 2-aryl and 2-aryloxy propionamides was identified and purified from brevibacterium sp. strain r312. oligonucleotide probes were designed from limited peptide sequence information and were used to clone the corresponding gene, named amda. highly significant homologies were found at the amino acid level between the deduced sequence of the enantiomer-selective amidase and the sequences of known amidases such as indoleacetamide hydrolases from pseudo ...19902254253
identification of an amino acid substitution in the bena, beta-tubulin gene of aspergillus nidulans that confers thiabendazole resistance and benomyl supersensitivity.we are using molecular genetic techniques to identify sites of interaction of beta-tubulin with benzimidizole anti-microtubule agents. we have developed a marker-rescue technique for cloning mutant alleles of the bena, beta-tubulin gene of aspergillus nidulans and have used the technique to clone two mutant bena alleles, bena16 and bena19. these are the only a. nidulans alleles known to confer resistance to the benzimidazole antimicrotubule agent thiabendazole and supersensitivity to other benzi ...19902257633
heterologous gene expression by filamentous fungi: secretion of human interleukin-6 by aspergillus nidulans.expression vectors for human interleukin-6 (hil6) contain an expression cassette consisting of the aspergillus niger glaa promoter and the aspergillus nidulans argb terminator. the secretion signals were either those of glaa or that of the authentic hil6 peptide. the constructs under study were introduced into a. nidulans and a. niger by means of cotransformation. no il6 activity could be detected in the medium of a cotransformed a. niger strain, although transcripts corresponding with the il6 c ...19902258049
a translocation activating the cryptic nitrogen regulation gene areb inactivates a previously unidentified gene involved in glycerol utilisation in aspergillus nidulans.the chromosome viii translocation breakpoint of the areb-404 translocation, selected for its ability to activate the cryptic nitrogen metabolism regulatory gene areb, and the mutation glcd-100 both lead to loss of mitochondrial fad-dependent sn-glycerol-3-phosphate dehydrogenase in aspergillus nidulans. these two lesions therefore define glcd, a second gene (in addition to glcb) where mutation can result in loss of this enzyme. the glcd gene has been localised to a centromere-proximal region of ...19902259335
fungal flora associated with combine harvester wheat and sorghum dusts from egypt.107 species and 8 species varieties belonging to 44 genera were collected from combine harvester wheat and sorghum dusts (35 genera and 91 species + 4 varieties) and from the atmosphere of their hay sites (26 genera and 69 species + 4 varieties) on glucose- and cellulose-czapek's dox agar at 28 degrees c and 45 degrees c. the mycoflora of wheat and sorghum dusts were basically similar on the two types of media and the most common fungi were: alternaria alternata, aspergillus flavus, a. fumigatus ...19902266490
solubilisation of a cell wall bound invertase in aspergillus nidulans.aspergillus nidulans produces an extracellular invertase when incubated in the presence of sucrose and about half of the activity produced was found to be associated with the mycelium. sixty percent of this mycelial invertase could be solubilised by simple mechanical disruption. among the agents tested for solubilisation of invertase, proteinase k and dithiothreitol were the most effective.19902272493
molecular basis for determining the sensitivity of eucaryotes to the antimitotic drug rhizoxin.rhizoxin, an antibiotic, exhibits potent anti-mitotic activity against most eucaryotic cells including those of higher vertebrates, plants and fungi by binding to beta-tubulin. the bena gene of three independently isolated rhizoxin-resistant (rhir) mutants of aspergillus nidulans was cloned, sequenced and compared with that of the wild-type, rhizoxin-sensitive (rhis) strain. in all three rhir mutants, the aac codon for asn-100 of the bena beta-tubulin gene was altered to atc, coding for ile. seq ...19902274023
genetic analysis of amds transformants of aspergillus niger and their use in chromosome mapping.the aspergillus nidulans gene coding for acetamidase (amds) was introduced into a. niger by transformation. twelve amd+ transformants were analysed genetically. the amds inserts were located in seven different linkage groups. in each transformant the plasmid was integrated in only a single chromosome. our (non-transformed) a. niger strains do not grow on acetamide and are more resistant to fluoroacetamide than the transformants. diploids hemizygous for the amds insert have the amd+ phenotype. we ...19902274031
alcohol dehydrogenase iii in aspergillus nidulans is anaerobically induced and post-transcriptionally alcohol dehydrogenase was shown to be induced in aspergillus nidulans by periods of anaerobic stress. this alcohol dehydrogenase was shown to correspond to the previously described cryptic enzyme, alcohol dehydrogenase iii (mcknight et al. 1985), by analysis of a mutation in the structural gene of alcohol dehydrogenase iii, alcc, created by gene disruption. survival tests on agar plates showed that this enzyme is required for long-term survival under anaerobic conditions. northern blot analys ...19902274033
sequence, organization and expression of the core histone genes of aspergillus nidulans.the core histone gene family of aspergillus nidulans was characterized. the h2a, h2b and h3 genes are unique in the a. nidulans genome. in contrast there are two h4 genes, h4.1 and h4.2. as previously reported for the h2a gene (may and morris 1987) introns also interrupt the other core histone genes. the h2b gene, like the h2a gene, is interrupted by three introns, the h3 and h4.1 gene are each interrupted by two introns and the h4.2 gene contains one intron. the position of the single intron in ...19902274040
expression and secretion in aspergillus nidulans and aspergillus niger of a cell surface glycoprotein from the cattle tick, boophilus microplus, by using the fungal amds promoter system.a cell surface glycoprotein (bm86) from cells of the digestive tract of the cattle tick boophilus microplus, which has been shown to elicit a protective immunological response in vaccinated cattle, was expressed and secreted in the filamentous fungi aspergillus nidulans and aspergillus niger by using the fungal amds promoter system. the cloned gene coded for the bm86 secretory signal and all of the bm86 mature polypeptide except for the hydrophobic carboxy-terminal segment. high levels of bm86 m ...19902275533
an electrophoretic karyotype of aspergillus electrophoretic karyotype of aspergillus niger was obtained using contour-clamped homogeneous electric field (chef) gel electrophoresis. chromosome-sized dna was separated into four bands. seven of the eight linkage groups could be correlated with specific chromosomal bands. for this purpose dna preparations from seven transformant strains of a. niger each carrying the heterologous amds gene of aspergillus nidulans on a different chromosome were analysed. some of the assignments were confirme ...19902277644
development of a homologous transformation system for aspergillus parasiticus with the gene encoding nitrate reductase.the nitrate reductase structural gene (niad) and an niad mutant strain were isolated from aspergillus parasiticus and used to develop a homologous transformation system. a transformation frequency of 110 to 120 transformants per microgram linear dna was obtained with the 10.9 kb plasmid psl82, which contained the niad gene of a. parasiticus. plasmid psl82 was also capable of complementing aspergillus nidulans fgsc a691, a niad mutant, though at lower frequencies. southern hybridization analyses ...19902277647
investigation of the het genes that control heterokaryon incompatibility between members of heterokaryon-compatibility (h-c) groups a and g1 of aspergillus nidulans.a chromosome assay method was used to determine the heterokaryon compatibility relationships between strains belonging to heterokaryon-compatibility (h-c) groups a and g1 of aspergillus nidulans. a hybrid strain (rd15) was isolated following protoplast fusion of strains 65-5 (h-ca) and 7-141 (h-cg1). the morphology of rd15 was severely abnormal compared to diploid strains of a. nidulans produced from heterokaryon-compatible haploid parents. inocula of rd15 were induced to haploidize on medium co ...19902283501
the genetics of conidiophore pigmentation in aspergillus nidulans.the grey-brown pigmentation of aspergillus nidulans conidiophores depends on the functions of two 'ivory' loci. ivob codes for a developmental specific phenol oxidase, and mutants accumulate its substrate n-acetyl-6-hydroxytryptophan. ivoa mutants are unable to make this substrate. yga mutants are also poorly pigmented, and extracts require copper salts to activate both the phenol oxidase and conidial laccase. ivoa and ivob mutants partially suppress the spore colour phenotype of yga mutants. co ...19902283502
an evolutionary comparison of acinetobacter calcoaceticus trpf with trpf genes of several organisms.the deduced amino acid sequence of acinetobacter calcoaceticus n-(5'-phosphoribosyl) anthranilate isomerase (prai), which is coded by trpf, was compared with trpf of caulobacter crescentus, escherichia coli, bacillus subtilis, saccharomyces cerevisiae, neurospora crassa, and aspergillus nidulans. sixty percent of identical or similar amino acids were located in alpha/beta tim (triose-phosphate isomerase) barrels and in residues important in substrate binding and catalysis. in addition, the analy ...19902299982
the purification and characterization of 3-dehydroquinase from streptomyces coelicolor.the enzyme 3-dehydroquinase was purified over 4000-fold to homogeneity from streptomyces coelicolor. the subunit mr estimated from polyacrylamide-gel electrophoresis in the presence of sds was 16,000. the native mr estimated by gel filtration on a superose 6 column was 209,000, indicating that the enzyme is a large oligomer. the enzyme was found to be extremely thermostable. this stability, along with the structural and kinetic properties of the enzyme, suggest that it is very similar to the qui ...19902306211
how does the cell count the number of ectopic copies of a gene in the premeiotic inactivation process acting in ascobolus immersus?repeated genes, artificially introduced in ascobolus immersus by integrative transformation, are frequently inactivated during the sexual phase. inactivation is observed in about 50% of meioses if duplicated genes are at ectopic chromosomal locations, and in 90% of meioses if genes are tandemly repeated. inactivation is associated with extensive methylation of the cytosine residues of the duplicated sequences and is induced in the still haploid nuclei of the dikaryotic cell which will undergo ka ...19902311917
studies on the mycoflora of aswan high dam lake, egypt: monthly variations.fifty-one species and one variety appertaining to twenty one genera of mesophilic fungi were recovered from the monthly samples of marginal water (44 species, 1 variety and 18 genera) and submerged mud (78 species, 1 variety and 30 genera) of aswan high dam lake during the period from july 1985 to december 1986. the most common species were aspergillus fumigatus, a. flavus, a. terreus, a. niger and penicillium funiculosum. the highest fungal populations were almost detected either in october, in ...19902352135
the complete dna sequence of the mitochondrial genome of podospora anserina.the complete 94,192 bp sequence of the mitochondrial genome from race s of podospora anserina is presented (1 kb = 10(3) base pairs). three regions unique to race a are also presented bringing the size of this genome to 100,314 bp. race s contains 31 group i introns (33 in race a) and 2 group ii introns (3 in race a). analysis shows that the group i introns can be categorized according to families both with regard to secondary structure and their open reading frames. all identified genes are tra ...19902357736
transformation of the rice blast fungus magnaporthe grisea to hygromycin b resistance.low frequency, integrative transformation of three fertile hermaphroditic strains of magnaporthe grisea has been achieved using plasmid pan7-1 and cosmid pan7-2, which contain an escherichia coli hygromycin b phosphotransferase gene linked to aspergillus nidulans regulatory sequences.19902357737
nucleases in the autolysis of filamentous fungi.rnase and dnase activities were studied in seven fungi of the subdivisions ascomycotina, zygomycotina and basidiomycotina during their autolysis, and extracellular and intracellular rnase and dnase were found. rnase specific activity reached higher levels than dnase specific activity in the culture liquid and mycelial extract, except in aspergillus nidulans. generally maximal rnase specific activities were observed at the onset of autolysis in the culture liquid. in the mycelial extract an incre ...19902379813
genetic analysis of aspergillus niger: isolation of chlorate resistance mutants, their use in mitotic mapping and evidence for an eighth linkage group.this paper describes the use of chlorate resistant mutants in genetic analysis of aspergillus niger. the isolated mutants could be divided into three phenotypic classes on the basis of nitrogen utilization. these were designated nia, nir and cnx as for aspergillus nidulans. all mutations were recessive to their wild-type allele in heterokaryons as well as in heterozygous diploids. the mutations belong to nine different complementation groups. in addition a complex overlapping complementation gro ...19902381424
localization of pyruvate carboxylase in organic acid-producing aspergillus strains.the localization of pyruvate carboxylase (cytosolic or mitochondrial) was studied in nine different aspergillus species (14 strains). in some species (a. aculeatus, a. flavus, a. foetidus, a. nidulans, a. ochraceus, and a. sojae), the pyruvate carboxylase activity could be detected only in the cytosolic fraction of the cells. pyruvate carboxylase has been found only in the mitochondrial fraction of two strains of aspergillus wentii. in aspergillus oryzae and in five strains of aspergillus niger, ...19902383004
high-efficiency transformation system for the biocontrol agents, trichoderma spp.we have developed an efficient transformation system based on the use of polyethylene glycol and cacl2 for the biocontrol agents, trichoderma spp. transformation was obtained with the plasmid pan7-1, carrying a bacterial hygromycin-resistance gene as a selectable marker, under the control of aspergillus nidulans heterologous expression signals. the system described here yielded 200-800 transformants per microgram of dna. transformants contained several copies of the plasmid integrated into their ...19902388561
survey of the mycoflora and mycotoxins of cotton seeds and cotton seed products in egypt.thirty-nine species and 16 fungal genera were isolated from egyptian cotton seeds, cotton seed meal and cotton seed cake on 1% glucose-czapek's agar medium incubated at 28 degrees c. aspergillus was the most frequent genus and it emerged in 87-100% of the samples contributing 70-98% of total fungi in the three substrates tested. the most common species were a. niger, a. flavus, a. fumigatus, a. terreus and rhizopus stolonifer; a. niger, a. fumigatus and penicillium corylophilum; and a. niger, a. ...19902388680
cloning and analysis of beta-tubulin gene from a protoctist.we have isolated and characterized by restriction endonuclease mapping, transcription pattern, and dna sequencing a beta-tubulin gene from the coenocytic freshwater protoctist, achlya klebsiana. the gene is intronless and has a single open reading frame that encodes a 444-amino acid residue polypeptide of mr 49,856. the protein shows a high degree of homology to other beta-tubulins, 85% identity to human beta-tubulin and 89% identity to beta-tubulin of the sporozoan (also a protoctist) plasmodiu ...19902394720
homologous transformation of cephalosporium acremonium with the nitrate reductase-encoding gene (niad).we report the development of a homologous transformation system for cephalosporium acremonium using the niad gene of the nitrate assimilation (na) pathway. mutants in the na pathway were selected on the basis of chlorate resistance by conventional means. screening procedures were developed to differentiate between nitrate reductase apoprotein structural gene mutants (niad) and molybdenum cofactor gene mutants (cnx) as wt c. acremonium, unlike most filamentous fungi, fails to grow on minimal medi ...19902401400
the aspergillus nidulans npea locus consists of three contiguous genes required for penicillin biosynthesis.clones of aspergillus nidulans genomic dna spanning 20 kb have been isolated and shown by a combination of classical and molecular genetic means to represent the npea locus, previously found to be one of four loci (npea, npeb, npec and nped) involved in the synthesis of penicillin. as well as containing the gene encoding the second enzyme for penicillin biosynthesis, namely isopenicillin n synthetase (ipns) (designated ipna), our results show that these clones (psta200, psta201 and psta207) cont ...19902403928
selective overexpression of the qute gene encoding catabolic 3-dehydroquinase in multicopy transformants of aspergillus nidulans.the three enzymes necessary to catabolize quinate to protocatechuate are inducible by quinic acid, and transcription of their corresponding genes is controlled by the action of a positively acting activator gene and a negatively acting repressor gene. transformed strains of aspergillus nidulans containing multiple copies of the activator gene (quta) but single copies of the other qut genes retain normal regulation of the gene cluster and do not show any overexpression of the three quinic acid ca ...19902405841
probing fungal mitochondrial evolution with trna.sequence data are now available for almost the entire complement of mitochondrial rrnas from five fungi: schizosaccharomyces pombe, saccharomyces cerevisiae, toropulis glabrata, aspergillus nidulans and neurospora crassa. analysis of these data show that the five mitochondria can be related to a common ancestor. the unusually high similarity between some s. pombe mt trnas may be due to a process similar to gene conversion. using the number of differences between trna pairs as a measure of the ev ...19852417640
5s rrna genes from aspergillus nidulans are not transcribed in saccharomyces cerevisiae.several different 5s rrna genes from aspergillus nidulans cloned in an escherichia coli--saccharomyces cerevisiae shuttle vector were introduced into s. cerevisiae cells by transformation. the a. nidulans 5s rrna genes were not transcribed in s. cerevisiae.19862436448
transformation of aspergillus nidulans by the argb gene.aspergillus nidulans argb mutant was transformed with the plasmid dna containing the argb gene. analysis of transformants revealed that transformation was due to integration of either argb gene alone or the whole plasmid dna into the a. nidulans genome. in 5 out of 23 transformants studied, integration took place in the locus different than the original argb locus. the amplification of integrated sequences was often observed. integrated dna was found to be mitotically stable, while the meiotic s ...19872442970
the mitochondrial genome of the fission yeast, schizosaccharomyces pombe. sequence of the large-subunit ribosomal rna gene, comparison of potential secondary structure in fungal mitochondrial large-subunit rrnas and evolutionary considerations.the dna sequence of the mitochondrial large subunit (lsu) rrna gene of schizosaccharomyces pombe has been determined. in the direction of transcription, this gene is located between the gene coding for subunit ii of cytochrome oxidase and a cluster of three trna genes. both the 5' and 3' ends of the lsu rrna have been mapped precisely: whereas the 5' end can be assigned unambiguously to a single nucleotide position, multiple 3' ends occur within a run of eight u residues. based on these results, ...19872446871
heat shock phenomena in aspergillus nidulans. ii. combined effect of heat and bleomycin to heat shock protein synthesis, survival rate and induction of mutations.the combined action of hyperthermia and bleomycin on aspergillus nidulans was studied at three different levels: mycelial protein synthesis, spore viability and induction of mutations. it was found that bleomycin treatment of preincubated mycelia during the heat shock enhances the incorporation of 35s-methionine into heat shock bands. furthermore, simultaneous treatment with hyperthermia (43 degrees c) and bleomycin results in greater cytotoxic activity in spores and in a higher induction rate o ...19872452026
repair of alkylation damage in the fungus aspergillus nidulans.the repair of alkylation damage in aspergillus nidulans was investigated. we have assayed soluble protein fractions for enzymes known to be involved in the repair of this type of damage in dna. the presence of a glycosylase activity that can remove 3-methyladenine from dna was demonstrated, as well as a dna methyltransferase activity that appears to act against o6-methylguanine. in addition to this approach, a series of mutants were isolated which display increased sensitivity to alkylating agen ...19882452348
distinction of cnxh cofactor gene-specified protomers with monoclonal antibodies to aspergillus nitrate reductase.the nitrate reductase (nadph) (ec from aspergillus nidulans is influenced directly by mutations in the structural gene (niad) for the major subunit of the enzyme and indirectly by mutation in any of several molybdenum cofactor loci (cnx). the cnxe-14 and the cnxh-3 mutants have been noted to contain the enzyme in two distinct forms following induction with nitrate. with the cnxh-3 as a prototype cnxh mutant, 10 other cnxh were found to be devoid of the assembled (dimeric) form of the en ...19882454152
tallysomycin-induced mitotic aneuploidy and point mutations in aspergillus nidulans.tallysomycin is an antibiotic compound structurally related to bleomycin, and like bleomycins and phleomycins also shows antitumour activity. we have investigated the genetic activity of tallysomycin in the ascomycete aspergillus nidulans for malsegregation of chromosomes at mitosis and for point mutations. we found that the antibiotic at very low concentrations from 0.025 to 0.2 micrograms/ml had an inhibitory effect on colonial growth of up to 50% and it increased the number of mitotic malsegr ...19862457783
developmental characterization and chromosomal mapping of the 5-azacytidine-sensitive fluf locus of aspergillus aspergillus nidulans, a fungus that possesses negligible, if any, levels of methylation in its genome, low concentrations of 5-azacytidine (5-ac) convert a high percentage of the cell population to fluffy phenotypic variants through a heritable modification of a single nuclear gene (m. tamame, f. antequera, j. r. villanueva, and t. santos, mol. cell. biol. 3:2287-2297, 1983). this new 5-ac-altered locus, designated here fluf1, was mapped as the closest marker to the centromere that has been i ...19882463470
a large cluster of highly expressed genes is dispensable for growth and development in aspergillus nidulans.we investigated the functions of the highly expressed, sporulation-specific spoc1 genes of aspergillus nidulans by deleting the entire 38-kb spoc1 gene cluster. the resultant mutant strain did not differ from the wild type in (1) growth rate, (2) morphology of specialized reproductive structures formed during completion of the asexual or sexual life cycles, (3) sporulation efficiency, (4) spore viability or (5) spore resistance to environmental stress. thus, deletion of the spoc1 gene cluster, r ...19892471671
enhancement of aspergillus nidulans transformation by the ans1 sequence.we have shown that the aspergillus nidulans ans1 sequence enhances the efficiency of transformation when introduced into vectors containing argb or trpc genes. increased efficiency of transformation is also observed when ans1 is present on a second cotransforming plasmid. in an attempt to explains the ans1 transactivity we have performed analysis of some cotransformants.19892484740
relationship between a 47-kda cytoplasmic membrane polypeptide and nitrate transport in anacystis nidulans.the polypeptide composition of cytoplasmic membranes of the cyanobacterium anacystis nidulans changes in response to variations in the nitrogen source available to the cells, differing specifically in the amount of a polypeptide of 47-kda molecular mass. synthesis of the polypeptide and expression of nitrate transport activity are repressed by ammonium. transfer of ammonium-grown cells to a medium containing nitrate as the sole nitrogen source results in parallel development of the 47-kda polype ...19892492194
thioredoxin is essential for photosynthetic growth. the thioredoxin m gene of anacystis nidulans.we have taken advantage of the transformation properties of the cyanobacterium anacystis nidulans r2 to investigate the importance of thioredoxin for photosynthetic growth. the gene encoding thioredoxin m, designated trxm, was cloned from a. nidulans using a synthetic oligonucleotide probe. based on the nucleotide sequence, thioredoxin m of a. nidulans is composed of 107 amino acids and shares 84, 48, and 48% sequence identity with thioredoxins from anabaena, spinach, and escherichia coli, respe ...19892492995
dna sequence and secondary structures of the large subunit rrna coding regions and its two class i introns of mitochondrial dna from podospora anserina.dna sequence analysis has shown that the gene coding for the mitochondrial (mt) large subunit ribosomal rna (rrna) from podospora anserina is interrupted by two class i introns. the coding region for the large subunit rrna itself is 3715 bp and the two introns are 1544 (r1) and 2404 (r2) bp in length. secondary structure models for the large subunit rrna were constructed and compared with the equivalent structure from escherichia coli 23s rrna. the two structures were remarkably similar despite ...19892494353
genes for the ribosomal proteins s12 and s7 and elongation factors ef-g and ef-tu of the cyanobacterium, anacystis nidulans: structural homology between 16s rrna and s7 mrna.a 6.5 kb region from the genome of the cyanobacterium, anacystis nidulans 6301 was cloned using the tobacco chloroplast gene for ribosomal protein s12 as a probe. sequence analysis revealed the presence of genes for ribosomal proteins s12 and s7 and elongation factors ef-g and ef-tu in this dna region. the arrangement is rps12 (124 codons) - 167 bp spacer - rps7 (156 codons) - 77 bp spacer - fus (694 codons) - 26 bp spacer - tufa (409 codons), which is similar to that of the escherichia coli str ...19892499762
cloning, sequence analysis and transcriptional study of the isopenicillin n synthase of penicillium chrysogenum as-p-78.a gene (ips) encoding the isopenicillin n synthase of penicillium chrysogenum as-p-78 was cloned in a 3.9 kb sali fragment using a probe corresponding to the amino-terminal end of the enzyme. the sali fragment was trimmed down to a 1.3 kb ncoi-bglii fragment that contained an open reading frame of 996 nucleotides encoding a polypeptide of 331 amino acids with an mr of 38012 dalton. the predicted polypeptide encoded by the ips gene of strain as-p-78 contains a tyrosine at position 195, whereas th ...19892499766
cloning and characterization of an anacystis nidulans r2 superoxide dismutase gene.the e. coli iron superoxide dismutase gene (sodb) was utilized as a heterologous probe to isolate a superoxide dismutase (sod) gene from anacystis nidulans r2. nucleotide sequence analysis revealed a 603 bp open reading frame with deduced amino acid sequence similar to other sod genes and to cyanobacterial superoxide dismutase amino-terminal sequences. assuming proteolytic cleavage of the initial methionine residue, the molecular mass of the mature a. nidulans r2 sodb polypeptide is 22,000 dalto ...19892501651
development of an expression system in aspergillus nidulans. 19892502450
expression of the escherichia coli beta-glucuronidase gene in industrial and phytopathogenic filamentous fungi.a chimaeric beta-glucuronidase (gus) gene has been created by ligating the aspergillus nidulans glyceraldehyde 3-phosphate dehydrogenase promoter to the coding sequence of the e. coli uida gene. co-transformation of this vector into a. nidulans, a. niger and the tomato pathogen fulvia fulva (syn. cladosporium fulvum (cooke] resulted in the expression of beta-glucuronidase. gus activity was detected by growth on agar media containing x-gluc and by enzyme assays of mycelial extracts. expression of ...19892504501
cloning and molecular characterisation of the amdr controlled gata gene of aspergillus nidulans.the gamma-amino-n-butyrate transaminase gene (gata) of aspergillus nidulans is one of several genes under positive control by the regulatory gene amdr (also called inta). the gata gene has been cloned from a cosmid library by complementation of a gata mutation. the sequence of a 2.6 kb genomic fragment containing gata has been determined. an open reading frame of 1497 bp within this sequence is interrupted by three putative introns and predicts a protein of 55 kda. northern analysis confirms con ...19892505051
expression of the trpc gene from penicillium chrysogenum in aspergillus nidulans.the heterologous expression in aspergillus nidulans of a gene involved in tryptophan biosynthesis from penicillium chrysogenum is described. with the chimeric plasmid ppc-31, which carries the cloned trpc gene, approximately 10-40 "stable" transformants per microgram of dna were obtained, with selection for complementation of the mutant allele. this frequency was increased 10-fold by the insertion of the ans1 fragment into the transformation vector. southern hybridization analysis revealed that ...19892508698
duplication of the phycocyanin operon in the unicellular cyanobacterium anacystis nidulans r2.two phycocyanin (pc) operons, each containing alpha- and beta-subunit genes, have been isolated from the unicellular cyanobacterium anacystis nidulans r2. using oligodeoxyribonucleotide probes for the pc-coding regions, three psti fragments were obtained and shown to contain the two operons, which are 2.7 kb apart, with a proposed gene order of 5'-(beta i-alpha i)-(beta ii-alpha ii)-3'. the nucleotide sequences of both alpha-subunit genes are identical, as are the beta-sequences and the 51-bp in ...19892511077
aspergillus and mouse share a new class of 'zinc finger' protein. 19892511649
[properties of 2,5-diamino-4-oxy-6-ribosylaminopyrimidine-5'- phosphate reductase, a enzyme of the second stage of flavinogenesis in pichia guilliermondii yeasts].2,5-diamino-4-oxy-6-ribosylaminopyrimidine-5'-phosphate reductase has been isolated from cells of pichia guilliermondii and subjected to 20-fold purification by treating extracts with streptomycin sulphate, frationating proteins (nh4)2so4 at 45-75% of saturation and chromatography on blue sepharose cl-6b. the use of gel filtration through sephadex g-150 and chromatography on deae-cellulose proved to be less effective for the enzyme purification. it has been established that it is 2,5-diamino-4-o ...19892511652
high-performance liquid chromatographic determination of delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine in complex media by precolumn derivatisation with dansylaziridine.a novel method is described for the trace level quantitation of the tripeptide delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine (acv) in complex fermentation media, using a high-performance liquid chromatographic, pre-column derivatisation technique. the procedure is based upon the reaction of the acv monomer with 5-dimethylaminonaphthalene-1-sulphonylaziridine (dansylaziridine) and produces a highly fluorescent product. reaction conditions between the reagent and tripeptide were investigated an ...19892512319
expression of an anacystis nidulans photolyase gene in escherichia coli; functional complementation and modified action spectrum of photoreactivation.the anacystis nidulans photolyase gene inserted in an expression vector plasmid was introduced into escherichia coli cells and the production of anacystis photolyase protein was confirmed by reaction with antibodies raised against photolyase purified from a. nidulans cells. the anacystis photolyase functioned in photoreactivation repair defective e. coli cells. the e. coli transformants exhibited an action spectrum with a maximum around 380 nm similar to that of e. coli photolyase in contrast wi ...19892516329
cobalt-induced inhibition of growth in cyanobacteria anabaena doliolum and anacystis nidulans: interaction with sulphur containing amino acids.cobalt, above 1 microm concentration was growth inhibitory for both a. doliolum and a. nidulans. its toxicity was mitigated by sulphur containing amino acids (cystine and cysteine), however, methionine could not mitigate the cobalt toxicity at all.19892517422
purification and characterisation of nad-glutamate dehydrogenase from aspergillus nidulans.nad-glutamate dehydrogenase has been purified from mycelia of a. nidulans. the enzyme comprises subunits of 110 kda. it is located in the cytosol. it is completely denatured by 1.0 m guanidine hydrochloride, and is not renatured by subsequent dilution. isophthalate is a strong competitive inhibitor and the enzyme is also inhibited by thiol reagents. the properties of the enzyme were compared to those from other fungi in terms of size, sensitivity to inhibitors, intracellular distribution and mod ...19892524418
genetic engineering of filamentous fungi.filamentous fungi are important in medicine, industry, agriculture, and basic biological research. for example, some fungal species are pathogenic to humans, whereas others produce beta-lactam antibiotics (penicillin and cephalosporin). industrial strains produce large amounts of enzymes, such as glucoamylase and proteases, and low molecular weight compounds, such as citric acid. the largest and most economically important group of plant pathogens are fungi. several fungal species have biologica ...19892525275
processing of mitochondrial rna in aspergillus nidulans.genes for cytochrome oxidase subunit i (oxia), atpase subunit 9, nadh dehydrogenase subunit 3 (ndhc) and cytochrome oxidase subunit ii (oxib) are located within a 7.2 kb (1 kb = 10(3) bases or base-pairs) segment of the aspergillus nidulans mitochondrial genome. northern hybridization shows that abundant rna molecules of 4.0, 2.5 and 1.5 kb, each containing copies of two or more genes, are transcribed from this region. the 4.0 kb molecule, which contains copies of each of the four genes but lack ...19892530353
production of cell wall-degrading enzymes by aspergillus nidulans: a model system for fungal pathogenesis of plants.the cell wall-degrading enzymes polygalacturonase and pectate lyase have been suggested to be crucial for penetration and colonization of plant tissues by some fungal pathogens. we have found that aspergillus nidulans (= emericella nidulans), a saprophytic ascomycete, produces levels of these enzymes equal to those produced by soft-rotting erwinia species. induction of polygacturonase and pectate lyase in a. nidulans requires substrate and is completely repressed by glucose. surprisingly, inocul ...19892535501
regulation of the aspergillus nidulans pectate lyase gene (pela).aspergillus nidulans pectate lyase was purified from culture filtrates. the enzyme catalyzed a random eliminative cleavage reaction, had an apparent molecular weight of 40,000, and a pl of 4.2. pectate lyase antisera were produced and used to identify pectate lyase clones in a cdna expression library. thirteen of 14 clones identified immunologically cross-hybridized. the identity of the single-copy pectate lyase gene, which we designated pela, was confirmed in two ways. first, several cdna clone ...19892535502
protein encoded by the third intron of cytochrome b gene in saccharomyces cerevisiae is an mrna maturase. analysis of mitochondrial mutants, rna transcripts proteins and evolutionary relationships.we have established the nucleotide sequence of the wild-type and that of a trans-acting mutant located in the third (bi3) intron of the saccharomyces cerevisiae mitochondrial cytochrome b gene. the intron, 1691 base-pairs long, has an open reading frame 1045 base-pairs long, in phase with the preceding exon and the mutation replaces the evolutionarily conserved gly codon of the second consensus motif by an asp codon and blocks the formation of mature cytochrome b mrna. splicing intermediates of ...19892538624
the bimg gene of aspergillus nidulans, required for completion of anaphase, encodes a homolog of mammalian phosphoprotein phosphatase aspergillus nidulans, the temperature-sensitive, recessive cell cycle mutation bimg11 causes an elevated mitotic index at restrictive temperature and an inability to complete the anaphase separation of daughter nuclei. we have shown that this mutation has an abnormally high content of nuclear phosphoproteins and that the wild-type gene encodes a type 1 protein phosphatase. we conclude that dephosphorylation of a key protein(s) is required to complete mitosis.19892544297
nucleotide sequence and regulation of expression of the aspergillus nidulans gdha gene encoding nadp dependent glutamate dehydrogenase.the nucleotide sequence of the aspergillus nidulans gdha gene encoding nadp linked glutamate dehydrogenase has been determined and northern blot analysis used to study the regulation of expression of this gene. the gdha gene is 1485 nucleotides long and, by comparison with the corresponding neurospora crassa am gene, has two putative introns of 53 nucleotides and a protein encoding region of 1380 nucleotides that codes for an inferred protein of 49.63 kda which shows regions of homology with glu ...19892550758
invasive aspergillus infection in chronic granulomatous disease: treatment with itraconazole. 19892555469
cloning of a new bidirectionally selectable marker for aspergillus strains.mutants that lack adenosine triphosphate sulfurylase (atpsase; ec are unable to use sulfate as sole source of sulfur and are also resistant to selenate. these mutants, denoted sc-, are readily obtained from any strain of aspergillus niger or aspergillus nidulans by the strong selection for selenate resistance. we have cloned the gene encoding atpsase from a. nidulans by complementation of an sc mutant strain of a. nidulans with a gene library and show that plasmids containing this gene ...19892558969
isolation of the faca (acetyl-coenzyme a synthetase) and acue (malate synthase) genes of aspergillus nidulans.acetate inducible genes of aspergillus nidulans were cloned via differential hybridization to cdna probes. using transformation of mutant strains the genes were identified as faca (acetyl-coenzyme a synthetase) and acue (malate synthase). the levels of rna encoded by these genes were shown to be acetate inducible and subject to carbon catabolite repression. induction is abolished in a facb mutant and carbon catabolite repression is relieved in a crea mutant.19892571070
ammonia assimilation by aspergillus nidulans: [15n]ammonia study.15n kinetic labelling studies were done on liquid cultures of wild-type aspergillus nidulans. the labelling pattern of major amino acids under 'steady state' conditions suggests that glutamate and glutamine-amide are the early products of ammonia assimilation in a. nidulans. in the presence of phosphinothricin, an inhibitor or glutamine synthetase, 15n labelling of glutamate, alanine and aspartate was maintained whereas the labelling of glutamine was low. this pattern of labelling is consistent ...19892574737
heterogeneity of 5s rna in fungal ribosomes.neurospora crassa has at least seven types of 5s rna genes (alpha, beta, gamma, epsilon, delta, zeta, and eta) with different coding regions. a high resolution gel electrophoresis system was developed to separate minor 5s rna's from the major 5s rna (alpha). a study of several neurospora crassa strains, four other species in the genus neurospora, members of two closely related genera, and three distantly related genera demonstrated that 5s rna heterogeneity is common among fungi. in addition, di ...19852579431
physical characterization of the aldehyde-dehydrogenase-encoding gene of aspergillus facilitate a better understanding of the regulation of alda, the gene encoding aldehyde dehydrogenase (alddh) in the ascomycete fungus, aspergillus niger, the gene has been physically characterized. the complete nucleotide (nt) sequence of the gene and its flanking regions has been determined. analysis of the gene has revealed the presence of three introns. the homologous gene in the related fungus, aspergillus nidulans, contains only two introns. the coding regions of these genes, excluding ...19892606357
tryptophan auxotrophic mutants in aspergillus niger: inactivation of the trpc gene by cotransformation mutagenesis.aspergillus niger tryptophan auxotrophic mutants have been isolated after uv irradiation of conidiospores. the mutants belong to two different complementation groups, trpa and trpb, which complement each other in heterokaryons. neither of the mutations could be complemented with the cloned a. niger trpc gene. to obtain a. niger trpc mutants in a direct way, gene inactivation by cotransformation was performed. for this purpose an in-frame gene fusion between the a. niger trpc and escherichia coli ...19892615762
amplified expression of ribulose bisphosphate carboxylase/oxygenase in pbr322-transformants of anacystis nidulans.prior research suggested that the genes for large (l) and small (s) subunits of ribulose bisphosphate carboxylase/oxygenase (rubisco) are amplified in ampicillin-resistant pbr322-transformants of anacystis nidulans 6301. we now report that chromosomal dna from either untransformed or transformed a. nidulans cells hybridizes with nick-translated [32p]-pbr322 at moderately high stringency. moreover, nick-translated [32-p]-pcs75, which is a puc9 derivative containing a psti insert with l and s subu ...19892644909
delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine synthetase from aspergillus nidulans. the first enzyme in penicillin biosynthesis is a multifunctional peptide synthetase.a multienzyme catalyzing the formation of delta-(l-alpha-aminoadipyl)-l-cysteinyl-d-valine, the first free intermediate in penicillin biosynthesis, was detected in an assay measuring the formation of tripeptide from l-[u-14c]valine in the presence of l-alpha-aminoadipic acid, l-cysteine, atp, mg2+ ions, and dithioerythritol. enzyme was extracted from dry mycelium using a buffer with a high glycerol concentration and thiol protective agent to stabilize enzyme activity. in five steps the enzyme wa ...19892645274
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