TitleAbstractYear(sorted ascending)
aspergillus nidulans polarity mutant swoa is complemented by protein o-mannosyltransferase pmta.previously swoa was identified in aspergillus nidulans as a single locus, temperature-sensitive (ts) mutant aberrant in polarity maintenance. swoa was complemented by transformation with a plasmid genomic library. the sequence of the complementing gene was identical to a previously submitted genbank sequence for pmta, a protein o-mannosyltransferase. the pmta/swoa-2 gene hybridized to three cosmids that are located on chromosome v and the swoa mutation was mitotically mapped to chromosome v. pmt ...200212431460
functional analysis of mlcr, a regulatory gene for ml-236b (compactin) biosynthesis in penicillium citrinum.the mlcr gene encodes a putative 50.2-kda protein with a zn(ii)(2)cys(6) dna-binding domain, which may be involved in the regulation of ml-236b biosynthesis in penicillium citrinum. the induction of ml-236b production appears to correlate with the expression of mlcr, and the ml-236b biosynthetic genes mlca- mlch, and occurs mostly during the stationary phase. the present study was designed to examine the effects of alterations in mlcr expression on ml-236b biosynthesis. we first set out to incre ...200212436257
cloning and characterization of the naga gene that encodes beta-n-acetylglucosaminidase from aspergillus nidulans and its expression in aspergillus oryzae.we isolated a beta-n-acetylglucosaminidase encoding gene and its cdna from the filamentous fungus aspergillus nidulans, and designated it naga. the naga gene contained no intron and encoded a polypeptide of 603 amino acids with a putative 19-amino acid signal sequence. the deduced amino acid sequence was very similar to the sequence of candida albicans hex1 and trichoderma harzianum nag1. yeast cells containing the naga cdna under the control of the gal1 promoter expressed beta-n-acetylglucosami ...200212450128
protein analysis in a pleomorphically deteriorated strain of the insect-pathogenic fungus metarhizium anisopliae.pleomorphic deterioration is a process where a fungal isolate loses the ability to produce conidia during repeated subculturing. we have previously isolated strains of the entomopathogenic fungus metarhizium anisopliae that have irreversibly lost the ability to produce conidia and only produce mycelia when grown on agar. gel electrophoresis was used to examine differences in intracellular protein patterns (urea-soluble proteins and urea-insoluble proteins (i.e., hydrophobins)) in conidiating and ...200212455610
aspergillus nidulans catalase-peroxidase gene (cpea) is transcriptionally induced during sexual development through the transcription factor stua.catalases, peroxidases, and catalase-peroxidases are important enzymes to cope with reactive oxygen species in pro- and eukaryotic cells. in the filamentous fungus aspergillus nidulans three monofunctional catalases have been described, and a fourth catalase activity was observed in native polyacrylamide gels. the latter activity is probably due to the bifunctional enzyme catalase-peroxidase, which we characterized here. the gene, named cpea, encodes an 81-kda polypeptide with a conserved motif ...200212455692
mcl1+, the schizosaccharomyces pombe homologue of ctf4, is important for chromosome replication, cohesion, and segregation.the fission yeast minichromosome loss mutant mcl1-1 was identified in a screen for mutants defective in chromosome segregation. missegregation of the chromosomes in mcl1-1 mutant cells results from decreased centromeric cohesion between sister chromatids. mcl1+ encodes a beta-transducin-like protein with similarity to a family of eukaryotic proteins that includes ctf4p from saccharomyces cerevisiae, sepb from aspergillus nidulans, and and-1 from humans. the previously identified fungal members o ...200212455694
aspergillus nidulans swof encodes an n-myristoyl transferase.polar growth is a fundamental process in filamentous fungi and is necessary for disease initiation in many pathogenic systems. previously, swof was identified in aspergillus nidulans as a single-locus, temperature-sensitive (ts) mutant aberrant in both polarity establishment and polarity maintenance. the swof gene was cloned by complementation of the ts phenotype and sequenced. the derived protein sequence had high identity with n-myristoyl transferases (nmts) found in fungi, plants, and animals ...200212455958
isolation and characterization of two ammonium permease genes, meaa and mepa, from aspergillus nidulans.ammonium and the analogue methylammonium are taken into the cell by active transport systems which constitute a family of transmembrane proteins that have been identified in fungi, bacteria, plants, and animals. two genes from aspergillus nidulans, mepa and meaa, which encode ammonium transporters with different affinities have been characterized. the mepa transporter exhibits the highest affinity for methylammonium (km, 44.3 microm); in comparison, the km for meaa is 3.04 mm. by use of targeted ...200212455974
calcium binding is required for calmodulin function in aspergillus explore the structural basis for the essential role of calmodulin (cam) in aspergillus nidulans, we have compared the biochemical and in vivo properties of a. nidulans cam (ancam) with those of heterologous cams. neither saccharomyces cerevisiae cam (sccam) nor a ca2+ binding mutant of a. nidulans cam (1234) interacts appreciably with a. nidulans cam binding proteins by an overlay assay or activates two essential camks, cmka and cmkb. in contrast, although vertebrate cam (vcam) binds a spectr ...200212455978
a g-protein beta subunit required for sexual and vegetative development and maintenance of normal g alpha protein levels in neurospora crassa.the genome of the filamentous fungus neurospora crassa contains a single gene encoding a heterotrimeric g-protein beta subunit, gnb-1. the predicted gnb-1 protein sequence is most identical to g beta proteins from the filamentous fungi cryphonectria parasitica and aspergillus nidulans. n. crassa gnb-1 is also 65% identical to the human gnb-1 protein but only 38 and 45% identical to g beta proteins from budding and fission yeasts. previous studies in animal and fungal systems have elucidated phen ...200212455986
g-protein signaling mediates asexual development at 25 degrees c but has no effect on yeast-like growth at 37 degrees c in the dimorphic fungus penicillium mameffei.the ascomycete penicillium marneffei is an opportunistic human pathogen exhibiting a temperature-dependent dimorphic switch. at 25 degrees c, p. marneffei grows as filamentous multinucleate hyphae and undergoes asexual development, producing uninucleate spores. at 37 degrees c, it forms uninucleate yeast cells which divide by fission. we have cloned a gene encoding a g alpha subunit of a heterotrimeric g protein from p. marneffei named gasa with high similarity to fada in aspergillus nidulans. t ...200212455992
characterization of inhibitor-resistant histone deacetylase activity in plant-pathogenic fungi.hc-toxin, a cyclic peptide made by the filamentous fungus cochliobolus carbonum, is an inhibitor of histone deacetylase (hdac) from many organisms. it was shown earlier that the hdac activity in crude extracts of c. carbonum is relatively insensitive to hc-toxin as well as to the chemically unrelated hdac inhibitors trichostatin and d85, whereas the hdac activity of aspergillus nidulans is sensitive (g. brosch et al., biochemistry 40:12855-12863, 2001). here we report that hc-toxin-resistant hda ...200212456002
polarity in filamentous fungi: establishment, maintenance and new axes.germ tube emergence in filamentous fungi appears to be similar to bud emergence in yeast. several key proteins (e.g. cdc42, septins, bni1 formin, rho1 and rho3) play common roles in polarity establishment and early polarity maintenance in both processes. although germ tube extension, which can be thought of as extreme polarity maintenance, uses some of the same genes, they are likely to be regulated differently. mutations in polarity maintenance genes often lead to a split tip in filamentous fun ...200212457701
uvsz1 mutation shows epistatic relations with uvsd153 and uvsj1 mutations without any involvement with checkpoint control in aspergillus nidulans.the participation of the recently described uvsz1 mutation in checkpoint control and the identification of epistatic relations between uvsz1 mutation and uvsd153 and uvsj1 mutations are provided. the effect of mutation uvsz1 in mitotic exchanges into paba-bi (chromosome i) and cho-nic (chromosome vii) genetic intervals has also been evaluated. the mutation uvsz1 was epistatic with regard to uvsd153 and uvsj1 mutations, with no involvement with checkpoint control. in contrast to mutations in uvsb ...200212462996
regulation of formation of the intracellular beta-galactosidase activity of aspergillus nidulans.the regulation of formation of the single intracellular beta-galactosidase activity of aspergillus nidulans was investigated. beta-galactosidase was not formed during growth on glucose or glycerol, but was rapidly induced during growth on lactose or d-galactose. l-arabinose, and -- with lower efficacy -- d-xylose also induced beta-galactosidase activity. addition of glucose to cultures growing on lactose led to a rapid decrease in beta-galactosidase activity. in contrast, in cultures growing on ...200212471499
altering the expression of two chitin synthase genes differentially affects the growth and morphology of aspergillus aspergillus oryzae, one full-length chitin synthase (chsb) and fragments of two other chitin synthases (csma and chsc) were identified. the deduced amino acid sequence of chsb was similar (87% identity) to chsb from aspergillus nidulans, which encodes a class iii chitin synthase. the sequence obtained for csma indicated that it had high similarity to class v chitin synthases. chsb and csma disruption strains and a strain in which chsb transcription was controlled were constructed using the ni ...200212480906
identification of the pathogenic aspergillus species by nested pcr using a mixture of specific primers to dna topoisomerase ii gene.for pcr-based identification of aspergillus species, a common primer of the dna topoisomerase ii genes of candida, aspergillus and penicillium, and species-specific primers of the genomic sequences of dna topoisomerase ii of a. fumigatus, a. niger, a. flavus (a. oryzae), a. nidulans and a. terreus were tested for their specificities in pcr amplifications. the method consisted of amplification of the genomic dna topoisomerase ii gene by a common primer set, followed by a second pcr with a primer ...200212597358
guido pontecorvo, 29 november 1907 - 25 september 1999.guido pontecorvo was elected a fellow of the royal society in 1955 for his contributions to the genetics of drosophilia and the fungus aspergillus nidulans. pontecorvo was a leading british geneticist, prominent in the decade preceding the discovery of dna, who enriched our understanding of genes and whose pioneering work on the parasexual cycle in fungi found application in human somatic cell genetics. known to friends as ponte, he had a strong personality. somewhat irascible but warm, with a w ...200213678073
sex and the single gene: meiotic silencing by unpaired dna. 200212571367
regulation of expression of the rhizopus oryzae uricase and urease enzymes.the regulation of intracellular urease and uricase activities was examined in rhizopus oryzae. urease activity (2.4 u/mg protein) was present in r. oryzae mycelium grown in minimal medium containing nh4ci as sole nitrogen source. this activity increased threefold under nitrogen derepression conditions, but no induction by urea was detected. control of urease activity in r. oryzae differs from that found in neurospora crassa but resembles the situation in aspergillus nidulans. no uricase activity ...200212619824
fungistatic activity of semecarpus anacardium linn. f nut extract.alcoholic extract of dry nuts of s. anacardium showed dose dependent antifungal activity in vitro against aspergillus fumigatus and candida albicans. at 400 mg/ml concentration, growth of both the fungi was inhibited and considerable reduction in size of cells and hyphae was observed. sporulation also decreased.200212635702
primary structure of the histone 2b gene in the white root rot fungus, rosellinia necatrix.the nucleotide sequence of the histone 2b (h2b) gene in the white root rot fungus, rosellinia necatrix, was determined. the gene has two introns in the coding region at positions conserved in the neurospora crassa and aspergillus nidulans h2b genes, but the third intron present in the h2b gene from n. crassa and a. nidulans is absent in the r. necatrix h2b gene. the amino acid sequence of the coding region of the r. necatrix gene resembled that of n. crassa and a. nidulans. therefore, the third ...200212652911
cloning and functional expression of an esterase gene in aspergillus parasitcus.within the 80 kb aflatoxin pathway gene cluster characterized earlier, and between adha and nora genes, we have identified an esta gene encoding an esterase from wild type strain aspergillus parasiticus srrc 143. the 1,500 bp genomic dna and 945 bp cdna sequences were determined for esta. outside of the aflatoxin pathway gene cluster, an additional copy of the esta gene (named esta2) was also cloned from the same a. parasiticus strain. comparison of the esta and esta2 sequences showed 9 substitu ...200212749588
biosynthesis of pyridoxine in saccharomyces cerevisiae--origin of the pyridoxine nitrogen atom differs under anaerobic and aerobic conditions.the amide nitrogen atom of glutamine is incorporated into pyridoxine in four eukaryotes (i.e., emericella nidulans, mucor racemosus, neurospora crassa and saccharomyces cerevisiae) and two prokaryotes (i.e., staphylococcus aureus and bacillus subtilis). however, in the prokaryotes pseudomonas putida, enterobacter aerogenes and escherichia coli, it is the nitrogen atom of glutamate that is incorporated into pyridoxine (j nutr sci vitaminol (2000) 46, 55-57). as these results were from experiments ...200212775110
[guttural pouch mycosis by emericella nidulans in a horse].a case of guttural pouch mycosis in a horse caused by emericella nidulans is reported for the first time in spain. the high incidence of e. nidulans in this special kind of mycoses is discussed.200212825984
cloning and transcription analysis of the aspergillus aculeatus no. f-50 endoglucanase 2 (cmc2) gene.the cmc2 gene, coding for an endoglucanase 2 (cmc2) of aspergillus aculeatus, was cloned using both genomic and cdna libraries, and sequenced. the gene consists of 1230 bp encoding a protein of 410 amino acid residues with a molecular mass of 43,697 da. the cmc2, composed of an n-terminal catalytic domain belonging to the family 5 of glycosyl hydrolases and a c-terminal cellulose-binding domain (cbd) belonging to the family i of cbds, showed identity with other fungal endoglucanases, particularl ...200216233338
molecular characterization of abc transporter-encoding genes in aspergillus a preliminary step towards characterizing genes encoding atp-binding cassette (abc) transporters that confer pleiotropic drug resistance in aspergillus, we used a pcr-based approach to isolate four dna fragments corresponding to different abc type transporter genes. dna sequencing and southern blot analysis confirmed that they were distinct genes, which were designated abca-d. one of these genes, abcd, was cloned and characterized. it was found to have a predicted 1,452-amino acid translation ...200214963824
mapping woronin body position in aspergillus nidulans.the positions of all woronin bodies in five germlings of aspergillus nidulans prepared by plunge freezing and freeze substitution were determined by transmission electron microscopy. as expected, woronin bodies were found near septa. high numbers of morphologically identical organelles were also found in apical regions. to verify that these organelles were authentic woronin bodies, we used antibodies raised against the neurospora crassa woronin body matrix protein hex1. anti-hex1 antibodies labe ...200221156495
regulation of the acuf gene, encoding phosphoenolpyruvate carboxykinase in the filamentous fungus aspergillus nidulans.phosphoenolpyruvate carboxykinase (pepck) is a key enzyme required for gluconeogenesis when microorganisms grow on carbon sources metabolized via the tricarboxylic acid (tca) cycle. aspergillus nidulans acuf mutants isolated by their inability to use acetate as a carbon source specifically lack pepck. the acuf gene has been cloned and shown to encode a protein with high similarity to pepck from bacteria, plants, and fungi. the regulation of acuf expression has been studied by northern blotting a ...200211741859
nek2 localizes to multiple sites in mitotic cells, suggesting its involvement in multiple cellular functions during the cell cycle.nek2 is a mammalian protein kinase that is structurally homologous to nima, a mitotic regulator in aspergillus nidulans. to understand the possible cellular processes in which nek2 participates during the cell cycle, we investigated the expression and subcellular localization of nek2 in mitotic cells. the nek2 protein levels were observed to be regulated in a cell cycle stage-specific manner in cultured cells. the cell cycle stage specificity of nek2 expression was also confirmed in cells underg ...200211785960
observation of egfp-visualized nuclei and distribution of vacuoles in aspergillus oryzae arpa null mutant.the arpa gene encoding arp1 (actin-related protein) was previously cloned and characterized from aspergillus oryzae. phenotypes of the arpa null mutant indicate its requirement for normal nuclear distribution and morphology of conidiophores. in this study, we further characterized the function of the arpa gene in distribution of organelles. for further analysis of nuclear migration in living cells, an expression system consisting of a fusion protein of aspergillus nidulans histone h2b and egfp ( ...200211786257
microbial, chemical and physical aspects of citrus waste composting.citrus waste supplemented with calcium hydroxide and with a c/n ratio of 24:1, ph of 6.3 and moisture content of 60% was composted by piling under shelter. with regular turning over of the pile and replenishment of moisture, the thermic phase lasted for 65-70 days and composting was completed after 3 months. compost thus prepared had an air-filled porosity of 14%, water-holding capacity of 590 ml l(-1), bulk density of 1.05 g cm(-3) and conductivity of 480 ms m(-1). phosphorus content (in mg l(- ...200211708757
mutations in sfda and sfdb suppress multiple developmental mutations in aspergillus nidulans.conidiophore morphogenesis in aspergillus nidulans occurs in response to developmental signals that result in the activation of brla, a well-characterized gene that encodes a transcription factor that is central to asexual development. loss-of-function mutations in flbd and other fluffy loci have previously been shown to result in delayed development and reduced expression of brla. flbd message is detectable during both hyphal growth and conidiation, and its gene product is similar to the myb fa ...200211805053
aspergillus nidulans septin aspb plays pre- and postmitotic roles in septum, branch, and conidiophore development.members of the septin family of proteins act as organizational scaffolds in areas of cell division and new growth in a variety of organisms. herein, we show that in the filamentous fungus aspergillus nidulans, the septin aspb is important for cellular division, branching, and conidiation both pre- and postmitotically. aspb localizes postmitotically to the septation site with an underlying polarity that is evident as cytokinesis progresses. this localization at the septation site is dependent on ...200211809826
sulphur amino acid synthesis in schizosaccharomyces pombe represents a specific variant of sulphur metabolism in fungi.schizosaccharomyces pombe, in contrast to saccharomyces cerevisiae and aspergillus nidulans, lacks cystathionine beta-synthase and cystathionine gamma-lyase, two enzymes in the pathway from methionine to cysteine. as a consequence, methionine cannot serve as an efficient sulphur source for the fungus and does not bring about repression of sulphur assimilation, which is under control of the cysteine-mediated sulphur metabolite repression system. this system operates at the transcriptional level, ...200211754480
involvement of the fungal nuclear migration gene nudc human homolog in cell proliferation and mitotic spindle formation.essential genes which are required for normal nuclear migration and play a role in developmental processes have been isolated from model genetic organisms. one such gene is nudc (nuclear distribution c), which is required for positioning nuclei in the cytoplasm of the filamentous fungus aspergillus nidulans and for normal colony growth. this gene is highly conserved, structurally and functionally, throughout evolution and the human homolog, hnudc, has been cloned. to study the function of nudc i ...200211795948
physiological characterisation of recombinant aspergillus nidulans strains with different crea genotypes expressing a. oryzae alpha-amylase.the physiology of three strains of aspergillus nidulans was examined--a crea deletion strain, a wild type crea genotype and a strain containing extra copies of the crea gene, all producing aspergillus oryzae alpha-amylase. the strains were cultured in batch and continuous cultivations and the biomass formation and alpha-amylase production was characterised. overexpression of the crea gene resulted in a lower maximum specific growth rate and a slightly higher repression of the alpha-amylase produ ...200211689252
pathogenic fungi: leading or led by ambient ph?summary pathogenic fungi have successfully attacked a wide range of hosts, which has forced them into ambient-adaptation. ph is one of the major ambient traits affecting the activity of pathogenicity factors secreted by the pathogen, hence, a ph sensing-response system was developed to enable the pathogen to tailor its arsenal to best fit its host. the pacc pala, b, c, f, h and i apparatus was first identified in aspergillus nidulans and later found in other fungi. secreted pathogenicity factors ...200320569410
alternative reproduction pathway in aspergillus nidulans.recombinant haploid segregants were recovered in filamentous fungus aspergillus nidulans (eidam) g. winter directly from the heterokaryons instead of diploid segregants (process described earlier as parameiosis). in spite of the reproductive complexity of a. nidulans, parameiosis has only now been observed in this fungus. since parameiosis was characterized by the occurrence of genetic recombination inside heterokaryotic hyphae, master strains (uvs+) and uvs mutants with high rate of both mitoti ...200314976715
regulation of cell cycle progression by calcium/calmodulin-dependent pathways.many hormones, growth factors, and cytokines regulate proliferation of their target cells. perhaps the most universal signaling cascades required for proliferative responses are those initiated by transient rises in intracellular calcium (ca(2+)). the major intracellular receptor for ca(2+) is calmodulin (cam). cam is a small protein that contains four ef-hand ca(2+) binding sites and is highly conserved among eukaryotes. in all organisms in which the cam gene has been deleted, it is essential. ...200314671000
apical growth and mitosis are independent processes in aspergillus is well established that cytoplasmic microtubules are depolymerized during nuclear division and reassembled as mitotic microtubules. mounting evidence showing that cytoplasmic microtubules were also involved in apical growth of fungal hyphae posed the question of whether apical growth became disrupted during nuclear division. we conducted simultaneous observations of mitosis (fluorescence microscopy) and apical growth (phase-contrast microscopy) in single hyphae of aspergillus nidulans to det ...200314714210
nitrogen metabolism and virulence of candida albicans require the gata-type transcriptional activator encoded by gat1.nitrogen acquisition and metabolism is central to microbial growth. a conserved family of zinc-finger containing transcriptional regulators known as gata-factors ensures efficient utilization of available nitrogen sources by fungi. gata factors activate expression of nitrogen catabolic pathways when preferred nitrogen sources are absent or limiting, a phenomenon known as nitrogen catabolite repression. gat1 of candida albicans encodes a gata-factor homologous to the area protein of aspergillus n ...200314617156
reactive oxygen species generated by microbial nadph oxidase noxa regulate sexual development in aspergillus nidulans.nadph oxidases (nox) have been characterized as higher eukaryotic enzymes used deliberately to produce reactive oxygen species (ros). the recent discovery of new functional members of the nox family in plants and animals has led to the recognition of the increasing importance of ros as signals involved in regulation of diverse cellular processes such as defence, growth and signalling. here, we address the role of nadph oxidase-generated ros in the biology of the filamentous fungus aspergillus ni ...200314622412
sub-families of alpha/beta barrel enzymes: a new adenine deaminase gene coding for an adenine deaminase has been described in eukaryotes. however, physiological and genetical evidence indicates that adenine deaminases are present in the ascomycetes. we have cloned and characterised the genes coding for the adenine deaminases of aspergillus nidulans, saccharomyces cerevisiae and schizosaccharomyces pombe. the a.nidulans gene was expressed in escherichia coli and the purified enzyme shows adenine but not adenosine deaminase activity. the open reading frames co ...200314643670
identification of proteins that interact with the central coiled-coil region of the human protein kinase nek1.nek protein kinases are evolutionarily conserved kinases structurally related to the aspergillus nidulans mitotic regulator nima. at least nine members of the nek family in vertebrates have been described to date, but for most of them the interacting protein partners are unknown. the pleiotropic deleterious effects and the formation of kidney cysts caused by nek1 mutation in mice emphasize its involvement in the regulation of diverse cellular processes and in the etiology of polycystic kidney di ...200314690447
transinhibition and voltage-gating in a fungal nitrate transporter.we have applied enzyme kinetic analysis to electrophysiological steady-state data of zhou et al. (zhou, j.j., trueman, l.j., boorer, k.j., theodoulou, f.l., forde, b.g., miller, a.j. 2000. a high-affinity fungal nitrate carrier with two transport mechanisms. j. biol. chem. 275:39894-9) and to new current-voltage-time records from xenopus oocytes with functionally expressed nrta (crna) 2h+-no3- symporter from emericella (aspergillus) nidulans. zhou et al. stressed two michaelis-menten (mm) mechan ...200314692450
characterization of phia, a gene essential for phialide development in aspergillus nidulans.we have previously identified genes and proteins involved in the fungal response to the streptomyces-produced antibiotics, bafilomycin b1 and concanamycin a, known inhibitors of v-atpases. using mrna differential display we identified an aspergillus nidulans gene with 30-fold up-regulated expression in the presence of bafilomycin. this gene, here denoted phia, and its gene product, were further characterized by targeted gene disruption and immunohistochemistry. phenotypically, the phia mutation ...200314599891
addendum to "the ph-induced glycosylation of secreted phosphatases is mediated in aspergillus nidulans by the regulatory gene pacc-dependent pathway" [fungal genet. biol. 39 (2003) 286-295]. 200314599896
intron requirement for afp gene expression in trichoderma viride.the 430 bp orf of the aspergillus giganteus antifungal protein (afp) gene, containing two small introns, was fused between the promoter and the terminator of the aspergillus nidulans trpc gene. the afp gene in this vector produced detectable levels of spliced mrna in trichoderma viride. in contrast, in the same vector configuration, its 285 bp intronless derivative showed no accumulation of mrna when transformed into t. viride. such expression results were confirmed at the protein level. this fa ...200314600221
a novel improved method for aspergillus nidulans transformation.we systematically investigated the efficiency of aspergillus nidulans transformation using protoplasts prepared from different stages of conidiospore germination and young mycelium. using standard integrative plasmids, increased transformation yields were obtained with protoplasts isolated from a specific stage coincident with germ tube emergence. this increase ranged, on the average, from two- to eightfold depending on different plasmids used. transformation efficiencies with a replicative plas ...200314607411
overlap of nuclear localisation signal and specific dna-binding residues within the zinc finger domain of pacc.the transcription factor pacc, mediating regulation of gene expression by ambient ph in the genetically amenable fungus aspergillus nidulans, contains a three zinc finger dna-binding domain (zf-dbd) including a nuclear localisation signal (nls). we selected 38 novel mutations impairing pacc function, of which 21 missense mutations identify individual residues essential for zf-dbd structure/function. our functional analysis agrees with our previous conclusion that finger 1 does not bind dna and p ...200314636595
arsenate transport and reduction in the hyper-tolerant fungus aspergillus sp. p37.aspergillus sp. p37 is able to grow at arsenate concentrations of 0.2 m--more than 20-fold higher than that withstood by reference microorganisms such escherichia coli, saccharomyces cerevisiae and aspergillus nidulans. this paper examines the transport of arsenate and phosphate and the reduction of arsenate in aspergillus sp. p37. these properties were compared with the corresponding properties of the archetype strain aspergillus nidulans ts1. both uptake and efflux of arsenate were inhibited b ...200314641588
compatible solutes protect against chaotrope (ethanol)-induced, nonosmotic water stress.water stress is one of the major stresses experienced by cellular systems and can take a number of distinct forms. in response to turgor-related osmotic stress, cells produce compatible solutes that are macromolecule protectants and also counteract the outflow of water from stressed cells. in this report we show that the germination of conidia of aspergillus nidulans, a sensitive indicator of water stress, in the presence of ethanol is correlated with the intracellular concentration of the compa ...200314660346
swohp, a nucleoside diphosphate kinase, is essential in aspergillus nidulans.the temperature-sensitive swoh1 mutant of aspergillus nidulans was previously identified in a screen for mutants with defects in polar growth. in the present work, we found that the swoh1 mutant swelled, lysed, and did not produce conidia during extended incubation at the restrictive temperature. when shifted from the permissive to the restrictive temperature, swoh1 showed the temperature-sensitive swelling phenotype only after 8 h at the higher temperature. the swoh gene was mapped to chromosom ...200314665452
the expression of sterigmatocystin and penicillin genes in aspergillus nidulans is controlled by vea, a gene required for sexual development.secondary metabolism is commonly associated with morphological development in microorganisms, including fungi. we found that vea, a gene previously shown to control the aspergillus nidulans sexual/asexual developmental ratio in response to light, also controls secondary metabolism. specifically, vea regulates the expression of genes implicated in the synthesis of the mycotoxin sterigmatocystin and the antibiotic penicillin. vea is necessary for the expression of the transcription factor aflr, wh ...200314665453
the sonb(nup98) nucleoporin interacts with the nima kinase in aspergillus nidulans.the aspergillus nidulans nima kinase is essential for mitotic entry. at restrictive temperature, temperature-sensitive nima alleles arrest in g2, before accumulation of nima in the nucleus. we performed a screen for extragenic suppressors of the nima1 allele and isolated two cold-sensitive son (suppressor of nima1) mutants. the sona1 mutant encoded a nucleoporin that is a homolog of yeast gle2/rae1. we have now cloned sonb, a second nucleoporin genetically interacting with nima. sonb is essentia ...200314668365
suppressor mutations bypass the requirement of flug for asexual sporulation and sterigmatocystin production in aspergillus nidulans.asexual sporulation (conidiation) in the filamentous fungus aspergillus nidulans requires the early developmental activator flug. loss of flug results in the blockage of both conidiation and production of the mycotoxin sterigmatocystin (st). to investigate molecular mechanisms of flug-dependent developmental activation, 40 suppressors of flug (sfgs) that conidiate without flug have been isolated and characterized. genetic analyses showed that an individual suppression is caused by a single secon ...200314668366
pka, ras and rgs protein interactions regulate activity of aflr, a zn(ii)2cys6 transcription factor in aspergillus nidulans.sterigmatocystin (st) is a carcinogenic polyketide produced by several filamentous fungi including aspergillus nidulans. expression of st biosynthetic genes (stc genes) requires activity of a zn(ii)2cys6 transcription factor, aflr. aflr is transcriptionally and post-transcriptionally regulated by a g-protein/camp/protein kinase a (pkaa) signaling pathway involving flba, an rgs (regulator of g-protein signaling) protein. prior genetic data showed that flba transcriptional regulation of aflr was p ...200314668367
the phoa and phob cyclin-dependent kinases perform an essential function in aspergillus nidulans.unlike pho85 of saccharomyces cerevisiae, the highly related phoa cyclin-dependent kinase (cdk) of aspergillus nidulans plays no role in regulation of enzymes involved in phosphorous acquisition but instead modulates differentiation in response to environmental conditions, including limited phosphorous. like pho85, aspergillus phoa is a nonessential gene. however, we find that expression of dominant-negative phoa inhibits growth, suggesting it may have an essential but redundant function. suppor ...200314668368
health symptoms caused by molds in a courthouse.a majority of occupants of a newly renovated historic courthouse in calgary, alberta, canada, reported multiple (3 or more) health-related symptoms, and several reported more than 10 persistent symptoms. most required at least 1 day outside of the building to recover from their symptoms. molds that produce mycotoxins, such as stachybotrys chartarum and emericella nidulans, were identified in the building, along with fungal organisms of the genera aspergillus, penicillium, streptomyces, cladospor ...200315143857
transformation of aspergillus aculeatus using the drug resistance gene of aspergillus oryzae and the pyrg gene of aspergillus nidulans.transformation systems for aspergillus aculeatus has been developed, based on the use of the pyrithiamine resistance gene of aspergillus oryzae and the orotidine-5'-monophosphate decarboxylase gene (pyrg) of aspergillus nidulans. an a. aculeatus mutant which can be transformed effectively by the a. nidulans pyrg gene was isolated as a transformation host. this is the first report of transformation of a. aculeatus.200314730150
[optimization of t-dna insertional mutagenesis and analysis of mutants of magnaporthe grisea].the rice blast fungus magnaporthe grisea causes one of the most destructive diseases of rice around the world. significant progresses have been made recently in genomics studies of the fungus, opening new era of the functional genomics which requires to generate a large scale of gene knockout mutants. it has been demonstrated that t-dna insertional mutagenesis is a powerful tool of functional genomics not only for plants but also for fungi. in this paper, we optimized the conditions for t-dna in ...200315969057
the siderophore system is essential for viability of aspergillus nidulans: functional analysis of two genes encoding l-ornithine n 5-monooxygenase (sida) and a non-ribosomal peptide synthetase (sidc).the filamentous ascomycete a. nidulans produces two major siderophores: it excretes triacetylfusarinine c to capture iron and contains ferricrocin intracellularly. in this study we report the characterization of two siderophore biosynthetic genes, sida encoding l-ornithine n(5)-monooxygenase and sidc encoding a non-ribosomal peptide synthetase respectively. disruption of sidc eliminated synthesis of ferricrocin and deletion of sida completely blocked siderophore biosynthesis. siderophore-deficie ...200312828635
growth inhibition of the filamentous fungus aspergillus nidulans by cadmium: an antioxidant enzyme approach.the heavy metal cadmium is very toxic to biological systems. although its effect on the growth of microorganisms and plants has been investigated, the response of antioxidant enzymes of aspergillus nidulans to cadmium is not well documented. we have studied the effect of cadmium (supplied as cdcl(2)) on catalase (cat), superoxide dismutase (sod) and glutathione reductase (gr). 0.005 mm cdcl(2) had a very slight stimulatory effect on the growth rate of a. nidulans, but at concentrations above 0.0 ...200312833209
re: watts et al. proteins 2002;48:161-168. 200312833536
a blumeria graminis gene family encoding proteins with a c-terminal variable region with homologues in pathogenic a study aimed at characterising, at the molecular level, the obligate biotrophic fungus blumeria graminis f. sp. hordei (bgh), we have identified a novel group of genes, the egh16h genes, and shown that two of these are up-regulated during primary infection of barley leaves. the genes have partial homology to a previously characterised bgh gene family, egh16. egh16 and egh16h are subfamilies of a larger multigene family with presently about 15 members identified in bgh. egh16h has about ten m ...200312853153
histone deacetylases in fungi: novel members, new facts.acetylation is the most prominent modification on core histones that strongly affects nuclear processes such as dna replication, dna repair and transcription. enzymes responsible for the dynamic equilibrium of histone acetylation are histone acetyltransferases (hats) and histone deacetylases (hdacs). in this paper we describe the identification of novel hdacs from the filamentous fungi aspergillus nidulans and the maize pathogen cochliobolus carbonum. two of the enzymes are homologs of saccharom ...200312853613
the cop9 signalosome is an essential regulator of development in the filamentous fungus aspergillus nidulans.the cop9 signalosome (csn) is a conserved multiprotein complex involved in regulation of eukaryotic development. the deduced amino acid sequences of two aspergillus nidulans genes, csnd and csne, show high identities to the fourth and fifth csn subunits of higher eukaryotes. the csnd transcript is abundant during vegetative growth as well as development and the corresponding protein accumulates in the nucleus. strains deleted for either csn gene are viable and show identical mutant phenotypes at ...200312864854
faster genetic identification of medically important aspergilli by using gellan gum as gelling agent in mycological media.using gellan gum as a substitute for agar-agar in a mycological medium and sequencing of the its 1 and 2 regions resulted in an accurate identification of aspergillus fumigatus, aspergillus nidulans, aspergillus terreus and aspergillus ustus within 24 h of subculture.200312867558
monacolin n, a compound resulting from derailment of type i iterative polyketide synthase function en route to lovastatin.a novel compound, monacolin n, has been isolated from fermentation cultures of aspergillus nidulans in which the lovastatin polyketide synthase genes lovb and lovc are heterologously expressed.200312868719
antifungal activity of human polymorphonuclear and mononuclear phagocytes against non-fumigatus aspergillus species.human phagocytic defenses against non-fumigatus aspergilli were compared with those against aspergillus fumigatus. monocyte-derived macrophages exhibited lower phagocytic capacities against non-fumigatus aspergilli, particularly a. nidulans and a. niger, compared with a fumigatus (p < 0.05). non-opsonized hyphae suppressed oxidative burst (as measured by superoxide anion production) of polymorphonuclear leukocytes (pmns). further, these cells responded with less vigorous oxidative burst to serum ...200312870194
identification of a topoisomerase i mutant, scsa1, as an extragenic suppressor of a mutation in scaa(nbs1), the apparent homolog of human nibrin in aspergillus nidulans.the mre11-rad50-nbs1 protein complex has emerged as a central player in the human cellular dna damage response, and recent observations suggest that these proteins are at least partially responsible for the linking of dna damage detection to dna repair and cell cycle checkpoint functions. mutations in scaa(nbs1), which encodes the apparent homolog of human nibrin in aspergillus nidulans, inhibit growth in the presence of the antitopoisomerase i drug camptothecin. this article describes the selec ...200312871905
does the detoxification of penicillin side-chain precursors depend on microsomal monooxygenase and glutathione s-transferase in penicillium chrysogenum?the glutathione (gsh) s-conjugation of 1,2-epoxy-3-(4'-nitrophenoxy)propane was catalysed predominantly by microsomal glutathione s-transferase (mgst) in penicillium chrysogenum. the specific mgst activity unlike the cytosolic gst (cgst) activity increased substantially when the penicillin side-chain precursor phenoxyacetic acid (poa) was included in the culture medium. therefore, a microsomal monooxygenase (causing possible release of epoxide intermediates) and mgst-dependent detoxification pat ...200312872310
the aspergillus nidulans metr gene encodes a bzip protein which activates transcription of sulphur metabolism genes.the identification, isolation and characterization of a new aspergillus nidulans positive-acting gene metr, which encodes a transcriptional activator of sulphur metabolism, is reported. metr mutants are tight auxotrophs requiring methionine or homocysteine for growth. mutations in the metr gene are epistatic to mutations in the negative-acting sulphur regulatory scon genes. the metr coding sequence is interrupted by a single intron of 492 bp which is unusually long for fungi. aspergillus nidulan ...200312890030
metabolic control analysis of xylose catabolism in aspergillus.a kinetic model for xylose catabolism in aspergillus is proposed. from a thermodynamic analysis it was found that the intermediate xylitol will accumulate during xylose catabolism. use of the kinetic model allowed metabolic control analysis (mca) of the xylose catabolic pathway to be carried out, and flux control was shown to be dependent on the metabolite levels. due to thermodynamic constraints, flux control may reside at the first step in the pathway, i.e., at the xylose reductase, even when ...200312892473
functional analysis of mutations in the human carnitine/acylcarnitine translocase in aspergillus nidulans.deficiency of the carnitine/acylcarnitine translocase (cact), the most severe disorder of fatty acid beta-oxidation, is usually lethal in both humans and animals, precluding the development of animal models of the disease. in contrast, cact deficiency is conditionally lethal in the fungus aspergillus nidulans, since loss-of-function mutations in acuh, the translocase structural gene, do not prevent growth on carbon sources other than ketogenic compounds, such as fatty acids. here, we describe th ...200312892634
the ph-induced glycosylation of secreted phosphatases is mediated in aspergillus nidulans by the regulatory gene pacc-dependent this communication, we show that the pacc(c)14 mutation drastically reduced the mannose and n-acetylglycosamine content of the paca-encoded acid phosphatase secreted by the fungus aspergillus nidulans when grown at 22 degrees c, ph 5.0, compared to a control strain. the staining after page was not observed for the paca-encoded acid phosphatase, while the pald-encoded pi-repressible alkaline phosphatase had an altered electrophoretic mobility. in addition, the secreted acid phosphatase also ha ...200312892641
molecular cloning of a phospholipase d gene from aspergillus nidulans and characterization of its deletion mutants.we cloned a gene plda encoding a protein containing phospholipase d (pld) motifs from a filamentous fungus aspergillus nidulans. the deduced protein product of plda consists of 833 amino acids and contains four conserved regions of a pld gene family. deletion mutants of plda grew and formed conidia in a normal manner. although pld and transphosphatidylation activities against phosphatidylcholine of the mutant cell extract did not change, the ca(2+)-dependent pld activity against phosphatidyletha ...200312892887
ura- host strains for genetic manipulation and heterologous expression of torulaspora delbrueckii.recently, the industrial and academic interest in the yeast torulaspora delbrueckii has increased notably due to its high resistance to several stresses. this characteristic has made of this organism a very attractive model to study the molecular basis of the stress response in yeast. however, very little is known about the physiology and genetics of this yeast, and the tools for its manipulation have not been developed. here, we have generated ura(-) strains of the baker's yeast t. delbrueckii ...200312892923
global nutritional profiling for mutant and chemical mode-of-action analysis in filamentous fungi.we describe a method for gene function discovery and chemical mode-of-action analysis via nutrient utilization using a high throughput nutritional profiling platform suitable for filamentous microorganisms. we have optimized the growth conditions for each fungal species to produce reproducible optical density growth measurements in microtiter plates. we validated the nutritional profiling platform using a nitrogen source utilization assay to analyze 21 aspergillus nidulans strains with mutations ...200312898394
glucose uptake in germinating aspergillus nidulans conidia: involvement of the crea and sora genes.d-glucose uptake in germinating wild-type aspergillus nidulans conidia is an energy-requiring process mediated by at least two transport systems of differing affinities for glucose: a low-affinity system (k(m) approximately 1.4 mm) and a high-affinity system (k(m) approximately 16 micro m). the low-affinity system is inducible by glucose; the high-affinity system is subject to glucose repression effected by the carbon catabolite repressor crea and is absent in sora3 mutant conidia, which exhibit ...200312904552
mannitol is required for stress tolerance in aspergillus niger conidiospores.d-mannitol is the predominant carbon compound in conidiospores of the filamentous fungus aspergillus niger and makes up 10 to 15% of the dry weight. a number of physiological functions have been ascribed to mannitol, including serving as a reserve carbon source, as an antioxidant, and to store reducing power. in this study, we cloned and characterized the a. niger mpda gene, which encodes mannitol 1-phosphate dehydrogenase (mpd), the first enzyme in the mannitol biosynthesis pathway. the mpda pr ...200312912888
diverged binding specificity of rim101p, the candida albicans ortholog of pacc.the biology of candida albicans, including dimorphism and virulence, is significantly influenced by environmental ph. the response to ambient ph includes the ph-conditional expression of several genes, which is directly or indirectly regulated by rim101p. rim101p is homologous to pacc, a transcription factor that regulates ph-conditional gene expression in aspergillus nidulans. pacc binds 5'-gccarg-3' sequences upstream of ph-responsive genes and either activates or represses transcription. the ...200312912891
secondary metabolites as co-markers in the taxonomy of aspergilli.the production of extracellular and intracellular secondary metabolites by 13 aspergillus species has been directly detected using the agar plug technique. in addition to several unknown compound a. aculeatus, a. ochraceus and a. terreus were found to be the highest producers of extracellular secondary metabolites, while the lowest producer species were a. tamarii, a. rugulosus in addition to a. oryzae whose secondary metabolites couldn't be detected by this technique. in case of intracellular s ...200312916724
mining microorganism est databases in the quest for new proteins.microorganisms with large genomes are commonly the subjects of single-round partial sequencing of cdna, generating expressed sequence tags (ests). usually there is a great distance between gene discovery by est projects and submission of amino acid sequences to public databases. we analyzed the relationship between available ests and protein sequences and used the sequences available in the secondary database, clusters of orthologous groups (cog), to investigate ests from eight microorganisms of ...200312917813
relationships between the ethanol utilization (alc) pathway and unrelated catabolic pathways in aspergillus nidulans.the ethanol utilization pathway in aspergillus nidulans is a model system, which has been thoroughly elucidated at the biochemical, genetic and molecular levels. three main elements are involved: (a) high level expression of the positively autoregulated activator alcr; (b) the strong promoters of the structural genes for alcohol dehydrogenase (alca) and aldehyde dehydrogenase (alda); and (c) powerful activation of alcr by the physiological inducer, acetaldehyde, produced from growth substrates s ...200312919319
male and female roles in crosses of aspergillus nidulans as revealed by vegetatively incompatible resolve the role of male and female nuclei and mitochondria in cleistothecium formation in the model organism aspergillus nidulans, we analysed the genetic constituents of cleistothecia from crosses between vegetatively compatible and incompatible parents. we used markers that enabled us to determine the nuclear genotype of the cleistothecial wall and the nuclear and mitochondrial genotype of the ascospores. in compatible parents, nuclear genomes and cytoplasm usually mix in the vegetative hy ...200312781672
alternative oxidase expression in neurospora crassa.when electron flow through the cytochrome-mediated electron transport chain is blocked by inhibitors or mutations, the mitochondria of neurospora crassa contain a kcn-insensitive alternative oxidase, encoded by the aod-1 gene, that transfers electrons directly from the ubiquinone pool to oxygen. the mechanism by which the enzyme is induced is unknown. comparison of the sequence upstream of the n. crassa aod-1 gene with the corresponding region of gelasinospora spp. and aspergillus nidulans revea ...200312781676
expression of a synthetic copy of the bovine chymosin gene in aspergillus awamori from constitutive and ph-regulated promoters and secretion using two different pre-pro sequences.a copy of the bovine chymosin gene (chy) with a codon usage optimized for its expression in aspergillus awamori was constructed starting from synthetic oligonucleotides. to study the ability of this filamentous fungus to secrete bovine prochymosin, two plasmids were constructed in which the transcriptional, translational, and secretory control regions of the a. nidulans gpda gene and pepb genes were coupled to either preprochymosin or prochymosin genes. secretion of a protein enzymatically and i ...200312783481
surface hydrophobicity of aspergillus nidulans conidiospores and its role in pellet formation.formation of pellets by aspergillus nidulans is primarily due to agglomeration of the fungal conidiospores. although agglomeration of conidiospores has been known for a long time, its mechanism has not been clearly elucidated. to study the influence of the fungal conidiospore wall hydrophobicity on conidiospore agglomeration, pellet formation of an a. nidulans wild type and strains deleted in the conidiospore-wall-associated hydrophobins dewa and roda was compared at different ph values. from co ...200312790678
different roles of the mre11 complex in the dna damage response in aspergillus nidulans.the mre11-rad50-nbs1 protein complex has emerged as a central player in the cellular dna damage response. mutations in scaanbs1, which encodes the apparent homologue of human nbs1 in aspergillus nidulans, inhibit growth in the presence of the anti-topoisomerase i drug camptothecin. we have used the scaanbs1 cdna as a bait in a yeast two-hybrid screening and report the identification of the a. nidulans mre11 homologue (mrea). the inactivated mrea strain was more sensitive to several dna damaging ...200312791148
expression of the red fluorescent protein dsred-express in filamentous ascomycete fungi.the recently reported red fluorescent protein dsred from the reef coral discosoma sp. represents a new marker that has been codon-optimized for high expression in mammalian cells. to facilitate expression of dsred in ascomycete fungi, we used the clone pdsred-express (clontech) for constructing a plasmid vector, ppgpd-dsred, containing the constitutive aspergillus nidulans glyceraldehyde 3-phosphate (gpd) promoter. this vector was used for co-transformation of penicillium paxilli, trichoderma ha ...200312799012
spindle formation in aspergillus is coupled to tubulin movement into the many important organisms, including many algae and most fungi, the nuclear envelope does not disassemble during mitosis. this fact raises the possibility that mitotic onset and/or exit might be regulated, in part, by movement of important mitotic proteins into and out of the nucleoplasm. we have used two methods to determine whether tubulin levels in the nucleoplasm are regulated in the fungus aspergillus nidulans. first, we have used benomyl to disassemble microtubules and create a pool of f ...200312802085
evaluation of aspergillus niger as host for virus-like particle production, using the hepatitis b surface antigen as a model.the filamentous fungus aspergillus niger was transformed with the hepatitis b virus s gene encoding the major viral envelope protein under control of the constitutive a. nidulans glyceraldehyde-3-phosphate dehydrogenase ( gpda) promoter. approximately seven copies of the expression cassette were integrated on the genome, resulting in high-level transcription of the s gene. production of the 24-kda s protein and a 48-kda s protein dimer in the membrane-associated protein fraction of the recombina ...200312802503
sex slows down the accumulation of deleterious mutations in the homothallic fungus aspergillus nidulans.coexistence of sexual and asexual reproduction within the same individual is an intriguing problem, especially when it concerns homothallic haplonts, like the fungus aspergillus nidulans. in this fungus asexual and sexual offspring have largely identical genotypes. this genetic model organism is an ideal tool to measure possible fitness effects of sex (compared to asex) resulting from causes other than recombination. in this article we show that slightly deleterious mutations accumulate at a low ...200312807769
adaptation to environmental ph in candida albicans and its relation to pathogenesis.for microorganisms that grow over a wide range of extracellular ph, systems must have evolved to sense and respond appropriately. the human opportunistic pathogen candida albicans colonizes and infects anatomical sites of diverse ph, including the oral and gastro-intestinal tracts and the vaginal cavity. the ability to sense and respond to neutral-alkaline environments is governed by signal transduction pathways, one of which culminates in the activation of the transcription factor, rim101p. the ...200312819929
glycerol dehydrogenase, encoded by gldb is essential for osmotolerance in aspergillus nidulans.we have characterized the aspergillus nidulans gldb gene encoding a nadp+-dependent glycerol dehydrogenase. a basal expression level was observed for gldb, which increased significantly under conditions of hyper-osmotic shock (1 m nacl). growth of strains in which gldb was disrupted was severely reduced on plates containing 1% glucose and 1 m nacl, but these strains were able to grow on plates containing 1 m nacl and 1% glycerol, arabitol, mannitol or erythritol. uptake of these polyols compensa ...200312823816
isolation of the carbon catabolite repressor (crea) gene from the plant-pathogenic fungus cochliobolus carbonum.the crea gene has been implicated in glucose repression in several fungi. the product of this gene, crea, binds to the promoter region of several enzymes and down-regulates gene expression. an ortholog of crea was isolated and characterized from the maize pathogenic fungus, cochliobolus carbonum. the deduced amino acid sequence of the c. carbonum crea gene is very similar to the crea proteins of aspergillus niger, gibberella fujikuroi, sclerotinia sclerotiorum and trichoderma reesei, as well as ...200312825351
molecular characterization and analysis of the acrb gene of aspergillus nidulans: a gene identified by genetic interaction as a component of the regulatory network that includes the creb deubiquitination enzyme.mutations in the acrb gene, which were originally selected through their resistance to acriflavine, also result in reduced growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of omega-amino acids, including gaba and beta-alanine, as sole carbon and nitrogen sources. the acrb2 mutation suppresses the phenotypic effects of mutations in the creb gene that encodes a regulatory deubiquitinating enzyme, and in the crec gene that enco ...200312750323
functionally distinct nucleic acid binding sites for a group i intron encoded rna maturase/dna homing endonuclease.a large number of group i introns encode a family of homologous proteins that either promote intron splicing (maturases) or are site-specific dna endonucleases that function in intron mobility (a process called "homing"). genetic studies have shown that some of these proteins have both activities, yet how a single protein carries out both functions remains obscure. the similarity between respective dna-binding sites and the rna structure near the 5' and 3' splice sites has fueled speculation tha ...200312758073
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