TitleAbstractYear(sorted descending)
time fluctuations and imaging in the sers spectra of fungal hypha grown on nanostructured substrates.surface-enhanced raman scattering (sers) spectroscopy is an emerging technique in biomolecular analysis that can have a tremendous impact in the life sciences. we report on the sers imaging of fungal hyphae grown on nanostructured sers active substrates engineered using semiconductor technologies. time fluctuations in the intensity and band position in the sers spectra measured on the same sample position with 1 s integration time have been observed indicating that the sers signal arises from a ...200717944510
in vitro susceptibilities of aspergillus spp. causing otomycosis to amphotericin b, voriconazole and itraconazole.otomycosis is worldwide in distribution and most commonly caused by aspergillus species. amphotericin b, itraconazole and voriconazole are used for the treatment of aspergillosis, but recently an increase in resistance to these agents has been reported. we aimed at investigating the in vitro activities of amphotericin b, voriconazole and itraconazole against aspergillus isolates causing otomycosis. mycological analysis of samples from the ear canals of patients was performed by culturing onto sa ...200717944704
establishment of the ambient ph signaling complex in aspergillus nidulans: pali assists plasma membrane localization of palh.the aspergillus nidulans ambient ph signaling pathway involves two transmembrane domain (tmd)-containing proteins, palh and pali. we provide in silico and mutational evidence suggesting that pali is a three tmd (3-tmd) protein with an n-terminal signal peptide, and we show that pali localizes to the plasma membrane. pali is not essential for the proteolytic conversion of the pacc translation product into the processed 27-kda form, but its absence markedly reduces the accumulation of the 53-kda i ...200717951518
the thioredoxin system of the filamentous fungus aspergillus nidulans: impact on development and oxidative stress response.redox regulation has been shown to be of increasing importance for many cellular processes. here, redox homeostasis was addressed in aspergillus nidulans, an important model organism for fundamental biological questions such as development, gene regulation or the regulation of the production of secondary metabolites. we describe the characterization of a thioredoxin system from the filamentous fungus a. nidulans. the a. nidulans thioredoxin a (antrxa) is an 11.6-kda protein with a characteristic ...200717631497
a small membrane-peripheral region close to the active center determines regioselectivity of membrane-bound fatty acid desaturases from aspergillus nidulans.fatty acid desaturases catalyze the introduction of double bonds at specific positions of an acyl chain and are categorized according to their substrate specificity and regioselectivity. the current understanding of membrane-bound desaturases is based on mutant studies, biochemical topology analysis, and the comparison of related enzymes with divergent functionality. because structural information is lacking, the principles of membrane-bound desaturase specificity are still not understood despit ...200717636265
protein environment facilitates o2 binding in non-heme iron enzyme. an insight from oniom calculations on isopenicillin n synthase (ipns).binding of dioxygen to a non-heme enzyme has been modeled using the oniom combined quantum mechanical/molecular mechanical (qm/mm) method. for the present system, isopenicillin n synthase (ipns), binding of dioxygen is stabilized by 8-10 kcal/mol for a qm:mm (b3lyp:amber) protein model compared to a quantum mechanical model of the active site only. in the protein system, the free energy change of o2 binding is close to zero. two major factors consistently stabilize o2 binding. the first effect, ...200717637052
a synchrotron ftir microspectroscopy investigation of fungal hyphae grown under optimal and stressed conditions.synchrotron ftir can provide high spatial resolution (<10 microm pixel size) in situ biochemical analyses of intact biotissues, an area of increasing importance in the post-genomic era, as gene functions and gene networks are coming under direct scrutiny. with this technique, we can simultaneously assess multiple aspects of cell biochemistry and cytoplasmic composition. in this paper, we report the first results of our synchrotron ftir examination of hyphae of three important fungal model system ...200717106657
lissencephaly and lis1: insights into the molecular mechanisms of neuronal migration and development.lissencephaly is a severe human neuronal migration defect characterized by a smooth cerebral surface, mental retardation and seizures. lis1 was first gene cloned in an organism important for neuronal migration, as it was deleted or mutated in patients with lissencephaly in a heterozygous fashion. studies in model organisms, particularly aspergillus nidulans, as well as those in the mouse, have uncovered an evolutionarily conserved pathway that involves lis1 and cytoplasmic dynein. this pathway c ...200717850624
transcriptional control of nmra by the bzip transcription factor meab reveals a new level of nitrogen regulation in aspergillus nidulans.fungi can use a diverse range of nitrogen sources. some nitrogen sources sustain a rapid growth rate and are used in preference to less readily metabolized nitrogen sources. the mechanisms involved in this control of nitrogen utilization have been studied in the model filamentous ascomycete, aspergillus nidulans. the gata transcription factor area is necessary for the expression of nitrogen-catabolic permeases and enzymes. area activity is controlled by multiple mechanisms including regulated ar ...200717854403
effect of selected natural dyes in reduction on colour changes of egyptian linen textiles by fungi.linen is the most historical egyptian textile fibre liable to fungal deterioration. fungal deterioration of dyed linen textiles may appear as undesirable different stains. in order to success in removing of fungal stains from biodeteriorated historical egyptian dyed linen textiles, it is necessary to understand the nature and causes of these stains, hence their subsequent removal. so this paper aims to investigate the effect of fungi on dyed linen textiles. in this study linen textile samples we ...200717867537
terrequinone a biosynthesis through l-tryptophan oxidation, dimerization and bisprenylation.the antitumor fungal metabolite terrequinone a, identified in extracts of aspergillus sp., is biosynthesized by the five-gene cluster tdia-tdie. in this work, we have overproduced all five proteins (tdia-tdie) in the bacterial host escherichia coli, fully reconstituting the biosynthesis of terrequinone a. this pathway involves aminotransferase activity, head-to-tail dimerization and bisprenylation of the scaffold to yield the benzoquinone natural product. we have established that tdid is a pyrid ...200717704773
arginine catabolism in aspergillus nidulans is regulated by the rrma gene coding for the rna-binding protein.expression of aspergillus nidulans arginine catabolism genes, agaa and otaa, is regulated at the level of transcription by a specific induction and two global carbon and nitrogen repression systems. post-transcriptional and/or post-translational mechanisms have also been proposed to operate additionally. gene tagging with transposon impala allowed us to select the rrma gene. rrma protein contains three conserved rrm domains, typical for rna-binding proteins. the gene has a complex structure with ...200717719249
role of the transcriptional activator xlnr of fusarium oxysporum in regulation of xylanase genes and virulence.fungal infection of plants involves degradation of the host cell wall through the action of lytic enzymes secreted by the pathogen. the role of these enzymes in virulence is difficult to determine due to their functional redundancy and, therefore, remains controversial. here, we have studied xlnr, a zinc-finger transcription factor from the vascular wilt pathogen fusarium oxysporum that is orthologous to the major transcriptional activator of xylanase genes in aspergillus spp. transcription of t ...200717722701
mitotic regulation by nima-related kinases.abstract: the nima-related kinases represent a family of serine/threonine kinases implicated in cell cycle control. the founding member of this family, the nima kinase of aspergillus nidulans, as well as the fission yeast homologue fin1, contribute to multiple aspects of mitotic progression including the timing of mitotic entry, chromatin condensation, spindle organization and cytokinesis. mammals contain a large family of eleven nima-related kinases, named nek1 to nek11. of these, there is now ...200717727698
the pan-ac assay: a single-reaction real-time pcr test for quantitative detection of a broad range of aspergillus and candida view of the growing incidence and the high mortality of invasive aspergillosis and candidiasis, adequate diagnostic techniques permitting timely onset of treatment are of paramount importance. more than 90 % of all invasive fungal infections in immunocompromised individuals can be attributed to candida and aspergillus species. to date, standardized techniques permitting rapid, sensitive and, no less importantly, economic screening for the clinically most relevant fungi are lacking. in the pre ...200717761478
fungal nucleobase transporters.early genetic and physiological work in bacteria and fungi has suggested the presence of highly specific nucleobase transport systems. similar transport systems are now known to exist in algae, plants, protozoa and metazoa. within the last 15 years, a small number of microbial genes encoding nucleobase transporters have been cloned and studied in great detail. the sequences of several other putative proteins submitted to databases are homologous to the microbial nucleobase transporters but their ...200717784857
effect of caspofungin on metabolite profiles of aspergillus species determined by nuclear magnetic resonance spectroscopy.invasive aspergillosis remains a potentially life-threatening infection, the incidence of which is increasing. current methods used to determine the susceptibilities of aspergillus strains to antifungal drugs are often unreliable. nuclear magnetic resonance (nmr) spectroscopy can identify the metabolic complement of microorganisms while monitoring nutrient utilization from the incubation medium. we used 600-mhz (1)h nmr spectroscopy to monitor the metabolic responses of five aspergillus species ...200717785514
asexual recombination in a uvsh mutant of aspergillus nidulans.mutations in the gene uvsh of aspergillus nidulans result in increased spontaneous chromosome instability and increased intragenic and intergenic mitotic recombination in homozygous diploids. the aim of the present work was to obtain a uvs mutant of a. nidulans and to use it for the isolation of asexual recombinants (parameiotic segregants). the mutant uvsh, named b511, showed normal frequency of meiotic recombination in sexual crosses and high frequency of parameiotic segregants in the parasexu ...200717657356
dioctatin a is a strong inhibitor of aflatoxin production by aspergillus parasiticus.dioctatin a (dota), a metabolite of streptomyces, is known to be an inhibitor of human dipeptidyl aminopeptidase ii. here, it was found that dota strongly inhibited aflatoxin production by aspergillus parasiticus, with an ic50 value of 4.0 microm. the mycelial growth of the fungus was not affected by the addition of dota at a concentration of 50 microm, but inhibition of conidiation was observed at the same concentration. dota inhibited production of norsolorinic acid, an early biosynthetic inte ...200717660441
mating type and the genetic basis of self-fertility in the model fungus aspergillus nidulans.sexual reproduction occurs in two fundamentally different ways: by outcrossing, in which two distinct partners contribute nuclei, or by self-fertilization (selfing), in which both nuclei are derived from the same individual. selfing is common in flowering plants, fungi, and some animal taxa. we investigated the genetic basis of selfing in the homothallic fungus aspergillus nidulans. we demonstrate that alpha and high-mobility group domain mating-type (mat) genes, found in outcrossing species, ar ...200717669651
rapid isolation of fungal genomic dna suitable for long distance pcr.a quick and reliable method for screening fungal transformants for specific genetic modifications is essential for many molecular applications. we have compared the applicability of a few rapid dna extraction methods for myrothecium and aspergillus and tested the resulting dna as to its suitability for pcr. for myrothecium gramineum, the highest dna concentration was obtained with the procedure described by n. vanittanakom et al. (j clin microbiol 2002, 40: 1739-1742). for a. nidulans, concentra ...200717680211
secondary chemicals protect mould from fungivory.the vast repertoire of toxic fungal secondary metabolites has long been assumed to have an evolved protective role against fungivory. it still remains elusive, however, whether fungi contain these compounds as an anti-predator adaptation. we demonstrate that loss of secondary metabolites in the soil mould aspergillus nidulans causes, under the attack of the fungivorous springtail folsomia candida, a disadvantage to the fungus. springtails exhibited a distinct preference for feeding on a mutant d ...200717686752
evidence for post-translational regulation of nrta, the aspergillus nidulans high-affinity nitrate, influx and efflux of (13)no(3)(-), and net fluxes of (14)no(3)(-) and (14)no(2)(-), were measured in aspergillus nidulans mutants niad171 and niia5, devoid of nitrate reductase (nr) and nitrite reductase (nir) activities, respectively. transcript and protein abundances of nrta, the a. nidulans principal high-affinity no(3)(-) transporter, were determined using semiquantitative reverse transcription-polymerase chain reaction and western blots, respectively. (13)no(3)(-) influx in niad171 wa ...200717688585
conrad: gene prediction using conditional random fields.we present conrad, the first comparative gene predictor based on semi-markov conditional random fields (smcrfs). unlike the best standalone gene predictors, which are based on generalized hidden markov models (ghmms) and trained by maximum likelihood, conrad is discriminatively trained to maximize annotation accuracy. in addition, unlike the best annotation pipelines, which rely on heuristic and ad hoc decision rules to combine standalone gene predictors with additional information such as ests ...200717690204
light represses conidiation in koji mold aspergillus the filamentous fungus aspergillus oryzae, there has been no report on photoreaction. here we investigated the effect of light in a. oryzae and found that conidiation was repressed by white light. this reaction is contrary to that of other aspergilli, which show abundant conidiation under light. moreover, red light also caused reduced conidiation. genome sequencing of a. oryzae indicated the existence of homologs of some light-related genes in other filamentous fungi. to approach the molecula ...200717690479
pina from aspergillus nidulans binds to ps/pt-p motifs using the same loop i and xp groove as mammalian pin1.binding of the cdc25c-t48 ligand to pina from aspergillus nidulans has been characterised by the identification of 15n and 1h resonances from 1h-15n hsqc nmr titration experiments using previous backbone assignments. it is shown that the binding site for the cdc25c-t48 ligand with pina is the same as in the mammalian protein pin1, although with a reduced binding affinity. it had previously been proposed that the arginine residue (r17) in the loop i region of the pin1 ww domain is essential for b ...200717693144
palc, one of two bro1 domain proteins in the fungal ph signalling pathway, localizes to cortical structures and binds vps32.palc, distantly related to saccharomyces cerevisiae peripheral endosomal sorting complexes required for transport iii (escrt-iii) component bro1p and one of six aspergillus nidulans ph signalling proteins, contains a bro1 domain. green fluorescent protein (gfp)-tagged palc is recruited to plasma membrane-associated punctate structures upon alkalinization, when ph signalling is active. palc recruitment to these structures is dependent on the seven transmembrane domain (7-tmd) receptor and likely ...200717696968
femtochemistry in enzyme catalysis: dna photolyase.photolyase uses light energy to split uv-induced cyclobutane pyrimidine dimers in damaged dna. this photoenzyme encompasses a series of elementary dynamical processes during repair function from early photoinitiation by a photoantenna molecule to enhance repair efficiency, to in vitro photoreduction through aromatic residues to reconvert the cofactor to the active form, and to final photorepair to fix damaged dna. the corresponding series of dynamics include resonance energy transfer, intraprote ...200717703066
purification and characterization of the feii- and alpha-ketoglutarate-dependent xanthine hydroxylase from aspergillus nidulans.his6-tagged xanthine/alpha-ketoglutarate (alphakg) dioxygenase (xana) of aspergillus nidulans was purified from both the fungal mycelium and recombinant escherichia coli cells, and the properties of the two forms of the protein were compared. evidence was obtained for both n- and o-linked glycosylation on the fungus-derived xana, which aggregates into an apparent dodecamer, while bacterium-derived xana is free of glycosylation and behaves as a monomer. immunological methods identify phosphothreo ...200717429948
target-based approach to inhibitors of histone arginine methyltransferases.lysine and arginine methyltransferases participate in the post-translational modification of histones and regulate key cellular functions. so far only one arginine methyltransferase inhibitor discovered by random screening was available. we present the first target-based approach to protein arginine methyltransferase (prmt) inhibitors. homology models of human and aspergillus nidulans prmt1 were generated from available x-ray structures of rat prmts. the nci diversity set was filtered by a targe ...200717432842
genetic manipulation of aspergillus nidulans: meiotic progeny for genetic analysis and strain construction.the multicellular microbial eukaryote aspergillus nidulans is an excellent model for the study of a wide array of biological processes. studies in this system contribute significantly to understanding fundamental biological principles and are relevant for biotechnology and industrial applications, as well as human, animal and plant fungal pathogenesis. a. nidulans is easily manipulated using classical and molecular genetics. here, we describe the storage and handling of a. nidulans and procedure ...200717446881
genetic manipulation of aspergillus nidulans: heterokaryons and diploids for dominance, complementation and haploidization analyses.the haploid microbial eukaryote aspergillus nidulans is a powerful genetic system, which allows analysis of a broad range of biological phenomena. in addition to conventional analysis of meiotic progeny in a single generation, parasexual analysis affords a rapid and convenient method for genetic analysis. we describe the construction of a. nidulans heterokaryons and diploids for use in genetic analysis to determine dominance and conduct complementation tests. we also describe the rapid mapping o ...200717446882
targeting polyamines of aspergillus nidulans by sirna specific to fungal ornithine decarboxylase gene.aspergillus nidulans is a filamentous, ubiquitous and opportunistic pathogenic fungus, which causes fatal invasive aspergillosis among immunocompromised patients. as a prelude to the investigations on the possible control of human fungal diseases by selective targeting of fungal polyamines that are essential for fungal growth and development by rnai strategy, we have examined the effect of sirna specific to a key polyamine biosynthesis gene ornithine decarboxylase (odc) on the in vitro germinati ...200717464842
mitotic recombination accelerates adaptation in the fungus aspergillus nidulans.understanding the prevalence of sexual reproduction in eukaryotes is a hard problem. at least two aspects still defy a fully satisfactory explanation, the functional significance of genetic recombination and the great variation among taxa in the relative lengths of the haploid and diploid phases in the sexual cycle. we have performed an experimental study to explore the specific advantages of haploidy or diploidy in the fungus aspergillus nidulans. comparing the rate of adaptation to a novel env ...200717465683
coupling the gal4 uas system with alcr for versatile cell type-specific chemically inducible gene expression in arabidopsis.the aspergillus alc regulon encodes a transcription factor, alcr, which regulates transcription from cognate promoters such as alca(p). in the presence of suitable chemical inducers, alcr activates gene expression from alca(p). the alc regulon can be transferred to other species and can be used to control the expression of reporter, metabolic and developmental genes in response to low-level ethanol exposure. in this paper, we describe a versatile system for targeting the alc regulon to specific ...200717470056
an eight-subunit cop9 signalosome with an intact jamm motif is required for fungal fruit body formation.fruit body formation in filamentous fungi is a complex and yet hardly understood process. we show here that protein turnover control is crucial for aspergillus nidulans development. deletion of genes encoding cop9 signalosome (csn) subunits 1, 2, 4, or 5 resulted in identical blocks in fruit body formation. the csn multiprotein complex controls ubiquitin-dependent protein degradation in eukaryotes. six csn subunits interacted in a yeast two-hybrid analysis, and the complete eight-subunit csn was ...200717470786
multiple fungal enzymes possess cysteine synthase activity in vitro.we present evidence that there are at least three aspergillus nidulans enzymes which catalyze in vitro the reaction of o-acetylserine (oas) with sulfide forming cysteine. this activity is shared by cysteine synthase (cs) encoded by the cysb gene, homocysteine synthase encoded by cysd and by at least one more enzyme. moreover, arginine, histidine or proline starvation leads to derepression of cs activity even in the cysb,cysd double mutant strains, while neither cysb nor cysd gene transcription i ...200717482430
role of respiration in the germination process of the pathogenic mold aspergillus fumigatus.inhalation of resting conidia is usually the first step of a systemic infection caused by the opportunistic fungal pathogen aspergillus fumigatus. in the lung, the inhaled spores encounter an environment that permits germination. however, the relative importance of certain environmental conditions for conidial activation and subsequent hyphae formation has so far not been analyzed in detail. in this study, we studied the role of oxygen during germination. we found that inhibitors of the respirat ...200717486408
germination, duplication cycle and septum formation are altered by caffeine, caffeic acid and cinnamic acid in aspergillus nidulans.phenolic and benzene compounds from vegetables have been described as being responsible for many biological activities including antifungal effects. caffeine, cinnamic and caffeic acids were here investigated for their action on a model fungus, aspergillus nidulans, at its initial stage of germination. conidia did not germinate in the presence of (1 mm) cinnamic acid. caffeine and caffeic acid exerted a negative effect on germination, on the nuclear duplication cycle and on first septum formatio ...200718297875
investigations into the taxonomy of the mushroom pathogen verticillium fungicola and its relatives based on sequence analysis of nitrate reductase and its regions.the full sequence of the nitrate reductase gene was obtained from a type isolate of verticilliumfungicola var. fungicola and used for phylogenetic analysis against other ascomycete fungi. sequencing obtained 2749 bp of coding region, 668 bp of 5' flanking sequence and 731 bp of 3' flanking sequence. in silico analysis indicated that the coding region contains a single intron and translates into an 893 amino acid protein, with blast analysis identifying five conserved nitrate reductase domains wi ...200718297878
improved protocols for functional analysis in the pathogenic fungus aspergillus available whole genome sequence for aspergillus flavus provides the opportunity to characterize factors involved in pathogenicity and to elucidate the regulatory networks involved in aflatoxin biosynthesis. functional analysis of genes within the genome is greatly facilitated by the ability to disrupt or mis-express target genes and then evaluate their result on the phenotype of the fungus. large-scale functional analysis requires an efficient genetic transformation system and the ability to ...200718039373
regulation of hyphal morphogenesis by cdc42 and rac1 homologues in aspergillus nidulans.the ability of filamentous fungi to form hyphae requires the establishment and maintenance of a stable polarity axis. based on studies in yeasts and animals, the gtpases cdc42 and rac1 are presumed to play a central role in organizing the morphogenetic machinery to enable axis formation and stabilization. here, we report that cdc42 (moda) and rac1 (raca) share an overlapping function required for polarity establishment in aspergillus nidulans. nevertheless, cdc42 appears to have a more important ...200718005099
[homology-dependent inactivation of ltr retrotransposons in genomes of aspergillus fumigatus and a. nidulans].repeat-induced point mutation (rip) is the most intriguing among the known mechanisms of repeated sequences inactivation because of its ability to produce irreversible mutation of repeated dna. discovered for the first time in neurospora crassa, rip is characterized by c:g to t:a transitions in duplicated sequences. the mechanisms and distribution of rip are still purely investigated. mobile elements are a common target for the processes which lead to homology-dependent silencing because of thei ...200718318114
identification of nutrient-dependent changes in extracellular ph and acid phosphatase secretion in aspergillus nidulans.the present study was designed to identify nutrient-dependent changes in extracellular ph and acid phosphatase secretion in the bia1 palc4 mutant strain of aspergillus nidulans. the palc4 mutant was selected as lacking alkaline phosphatase, but having substantially increased acid phosphatase activity when grown on solid minimal medium under phosphate starvation, ph 6.5. gene palc was identified as a putative member of a conserved signaling cascade involved in ambient alkaline sensing whose sole ...200718050093
sexual and vegetative compatibility genes in the aspergilli.gene flow within populations can occur by sexual and/or parasexual means. analyses of experimental and in silico work are presented relevant to possible gene flow within the aspergilli. first, the discovery of mating-type (mat) genes within certain species of aspergillus is described. the implications for self-fertility, sexuality in supposedly asexual species and possible uses as phylogenetic markers are discussed. second, the results of data mining for heterokaryon incompatibility (het) and pr ...200718490952
eurotiomycetes: eurotiomycetidae and chaetothyriomycetidae.the class eurotiomycetes (ascomycota, pezizomycotina) is a monophyletic group comprising two major clades of very different ascomycetous fungi: (i) the subclass eurotiomycetidae, a clade that contains most of the fungi previously recognized as plectomycetes because of their mostly enclosed ascomata and prototunicate asci; and (ii) the subclass chaetothyriomycetidae, a group of fungi that produce ascomata with an opening reminiscent of those produced by dothideomycetes or sordariomycetes. in this ...200617486980
comparative studies of differential expression of chitinolytic enzymes encoded by chia, chib, chic and naga genes in aspergillus nidulans.n-acetyl-d-glucosamine, chito-oligomers and carbon starvation regulated chia, chib, and naga gene expressions in aspergillus nidulans cultures. the gene expression patterns of the main extracellular endochitinase chib and the n-acetyl-beta-d-glucosaminidase naga were similar, and the chib-naga enzyme system may play a morphological and/or nutritional role during autolysis. alterations in the levels of reactive oxygen species or in the glutathione-glutathione disulfide redox balance, characterist ...200617455791
metabolic network driven analysis of genome-wide transcription data from aspergillus nidulans.aspergillus nidulans (the asexual form of emericella nidulans) is a model organism for aspergilli, which are an important group of filamentous fungi that encompasses human and plant pathogens as well as industrial cell factories. aspergilli have a highly diversified metabolism and, because of their medical, agricultural and biotechnological importance, it would be valuable to have an understanding of how their metabolism is regulated. we therefore conducted a genome-wide transcription analysis o ...200617107606
a point mutation in the aspergillus nidulans sonbnup98 nuclear pore complex gene causes conditional dna damage sensitivity.the nuclear pore complex (npc) is embedded in the nuclear envelope where it mediates transport between the cytoplasm and nucleus and helps to organize nuclear architecture. we previously isolated sonb1, a mutation encoding a single amino acid substitution within the aspergillus nidulans sonbnnup98 npc protein (nucleoporin). here we demonstrate that this mutation causes marked dna damage sensitivity at 42 degrees . although sonbnnup98 has roles in the g2 transition, we demonstrate that the g2 dna ...200617028324
upstream and downstream regulation of asexual development in aspergillus fumigatus.the opportunistic human pathogen aspergillus fumigatus produces a large quantity of asexual spores (conidia), which are the primary agent causing invasive aspergillosis in immunocompromised patients. we investigated the mechanisms controlling asexual sporulation (conidiation) in a. fumigatus via examining functions of four key regulators, gpaa (galpha), afflba (rgs), afflug, and afbrla, previously studied in aspergillus nidulans. expression analyses of gpaa, afflba, afflug, afbrla, and afweta th ...200617030990
the intracellular siderophore ferricrocin is involved in iron storage, oxidative-stress resistance, germination, and sexual development in aspergillus nidulans.iron is required by most organisms, but an excess of this metal is potentially toxic. consequently, uptake and intracellular storage of iron are tightly controlled. the filamentous fungus a. nidulans lacks the iron storage compound ferritin but possesses an intracellular siderophore, which is accumulated in a highly regulated manner as iron-free desferri-ferricrocin or iron-containing ferricrocin via transcriptional regulation of the nonribosomal peptide synthetase sidc. biosynthesis of desferri ...200617030991
transcriptome analysis of aspergillus nidulans exposed to camptothecin-induced dna damage.we have used an aspergillus nidulans macroarray carrying sequences of 2,787 genes from this fungus to monitor gene expression of both wild-type and uvsb(atr) (the homologue of the atr gene) deletion mutant strains in a time course exposure to camptothecin (cpt). the results revealed a total of 1,512 and 1,700 genes in the wild-type and uvsb(atr) deletion mutant strains that displayed a statistically significant difference at at least one experimental time point. we characterized six genes that h ...200617030995
expression profile of amylolytic genes in aspergillus nidulans.aspergillus nidulans possessed 16 putative amylolytic genes consisting of 7 alpha-glucosidase (agda-f), 7 alpha-amylase (amya-f), and 2 glucoamylase (glaa and b) genes on the genome. among them, the agda, agdb, agde, agdf, amya, amyb, amyf, and glab genes were induced by isomaltose. amyr, a zn(ii)(2)cys(6) transcription factor, was required for the induction. the isomaltose-inducible genes possessed at least one consensus sequence for amyr binding, 5'-cggn(8)cgg, on each promoter region. none of ...200617031028
discovery of aspoquinolones a-d, prenylated quinoline-2-one alkaloids from aspergillus nidulans, motivated by genome mining.motivated by the observation that the aspergillus nidulans genome bears multiple anthranilic acid synthase gene copies, the fungal metabolome was reinvestigated under various fermentation conditions, resulting in the discovery of novel prenylated quinolin-2-one alkaloids, two of which bear unprecedented terpenoid side chains.200617036148
isolation of cell wall mutants in aspergillus nidulans by screening for hypersensitivity to calcofluor a first step toward identifying novel genes of wall metabolism in filamentous fungi, we have screened a collection of aspergillus nidulans mutants for strains exhibiting hypersensitivity toward the chitin binding agent calcofluor white (cfw). this strategy has been used previously to identify cell wall mutants in saccharomyces cerevisiae. we have identified 10 mutants representing eight loci, designated cala through calh, for calcofluor hypersensitivity. all cal mutants are impaired for sporu ...200617040069
the aspergillus nidulans rcoa gene is required for vea-dependent sexual development.the aspergillus nidulans rcoadelta mutant exhibits growth and developmental defects. we show that the rcoadelta mutant lacks cleistothecia and is self-sterile. in crosses with wild-type strains, rcoadelta nuclei do not contribute to the cleistothecial walls. furthermore, sexual development resulting from vea overexpression is rcoa dependent, indicating that rcoa lies downstream of vea in the sexual development pathway.200616980390
calmodulin concentrates at the apex of growing hyphae and localizes to the spitzenkörper in aspergillus nidulans.the calmodulin (cam) localization pattern in the growing hyphal tip of aspergillus nidulans was studied with the functional gfp::cam fusion protein. a faint tip-high gradient of cam was found in the growing hyphal tip, with cam highly localized in the region corresponding to the spitzenkörper forming a bright granule. the position of highly concentrated cam in the extreme apex seemed to determine the orientation of the hypha. the normal pattern of cam localization was also shown to be dependent ...200616983484
the aspergillus fumigatus cellobiohydrolase b (cbhb) promoter is tightly regulated and can be exploited for controlled protein expression and rnai.the utility of the aspergillus fumigatus cellobiohydrolase cbhb promoter for controlled gene expression has been investigated. cbhb message was present at high levels in the presence of carboxymethylcellulose and undetected in the presence of glucose. a reporter construct using the cbhb promoter showed similar behaviour and gave lower message levels than the aspergillus nidulans alca promoter under repressing conditions. an rnai construct driven by the cbhb promoter was used to down-regulate the ...200616984401
systematic deletion and mitotic localization of the nuclear pore complex proteins of aspergillus define the extent of the modification of the nuclear pore complex (npc) during aspergillus nidulans closed mitosis, a systematic analysis of nuclear transport genes has been completed. thirty genes have been deleted defining 12 nonessential and 18 essential genes. several of the nonessential deletions caused conditional phenotypes and self-sterility, whereas deletion of some essential genes caused defects in nuclear structure. live cell imaging of endogenously tagged npc proteins (nups) revea ...200616987955
application of electron tomography to fungal ultrastructure studies.access to structural information at the nanoscale enables fundamental insights into many complex biological systems. the development of the transmission electron microscope (tem) has vastly increased our understanding of multiple biological systems. however, when attempting to visualize and understand the organizational and functional complexities that are typical of cells and tissues, the standard 2-d analyses that tem affords often fall short. in recent years, high-resolution electron tomograp ...200616995909
identification and comparative analysis of sixteen fungal peptidyl-prolyl cis/trans isomerase repertoires.the peptidyl-prolyl cis/trans isomerase (ppiase) class of proteins is present in all known eukaryotes, prokaryotes, and archaea, and it is comprised of three member families that share the ability to catalyze the cis/trans isomerisation of a prolyl bond. some fungi have been used as model systems to investigate the role of ppiases within the cell, however how representative these repertoires are of other fungi or humans has not been fully investigated.200616995943
novel mitogen-activated protein kinase mpkc of aspergillus fumigatus is required for utilization of polyalcohol sugars.the genome of aspergillus fumigatus has four genes that encode mitogen-activated protein kinases (mapks), saka/hoga, mpka, mpkb, and mpkc. the functions of the mpkb and mpkc mapks are unknown for a. fumigatus and the closely related and genetically amenable species aspergillus nidulans. mpkc deletion mutants of a. fumigatus were made and their phenotypes characterized. the mpkc deletion mutants were viable and had normal conidial germination and hyphal growth on minimal or complete media. this i ...200616998074
site-directed mutagenesis of selected residues at the active site of aryl-alcohol oxidase, an h2o2-producing ligninolytic enzyme.aryl-alcohol oxidase provides h(2)o(2) for lignin biodegradation, a key process for carbon recycling in land ecosystems that is also of great biotechnological interest. however, little is known of the structural determinants of the catalytic activity of this fungal flavoenzyme, which oxidizes a variety of polyunsaturated alcohols. different alcohol substrates were docked on the aryl-alcohol oxidase molecular structure, and six amino acid residues surrounding the putative substrate-binding site w ...200616999821
efficacy of caspofungin against aspergillus flavus, aspergillus terreus, and aspergillus nidulans.the echinocandin caspofungin is a potent inhibitor of the activity of 1,3-beta-d-glucan synthase from aspergillus flavus, aspergillus terreus, and aspergillus nidulans. in murine models of disseminated infection, caspofungin prolonged survival and reduced the kidney fungal burden. caspofungin was at least as effective as amphotericin b against these filamentous fungi in vivo.200617015628
glucose-mediated repression of autolysis and conidiogenesis in emericella nidulans.glucose-mediated repression of autolysis and sporulation was studied in submerged emericellanidulans (anam. aspergillus nidulans) cultures. null mutation of the crea gene, which encodes the major carbon catabolite repressor crea in e. nidulans, resulted in a hyperautolytic phenotype characterized by increased extracellular hydrolase production and dry cell mass declination. interestingly, glucose, as well as the glucose antimetabolite 2-deoxy-d-glucose, repressed autolysis and sporulation in bot ...200617018254
opposing signals differentially regulate transcript stability in aspergillus nidulans.a good model for gene regulation, requiring the organism to monitor a complex and changing environment and respond in a precise and rapid way, is nitrogen metabolism in aspergillus nidulans. this involves co-ordinated expression of hundreds of genes, many dependent on the transcription factor area, which monitors the nitrogen state of the cell. area activity is in part modulated by differential degradation of its transcript in response to intracellular glutamine. here we report that glutamine tr ...200617020584
g-protein and camp-mediated signaling in aspergilli: a genomic perspective.we have carried out an in silico exploration of the genomes of aspergillus nidulans, aspergillus fumigatus, and aspergillus oryzae, and identified components of g-protein/camp-mediated signaling. putative g-protein coupled receptors (gpcrs) were distributed over nine classes. the gpcrs within classes were well conserved among aspergilli but varied in other ascomycetes. as previously observed in a. nidulans and other fungi, three galpha, one gbeta, and one ggamma subunits of g proteins were ident ...200616546420
[recombinant aspergillus niger glucose oxidase expressed in trichoderma reesei].it was expected that recombinant aspergillus niger glucose oxidase could be expressed in trichoderma reesei with stable activity. t. reesei cbhi promoter--cbhi ss. gene--a. niger glucose oxidase gene--t. reesei cbhi terminator--a. nidulans gpd promoter--e. coli hygromycin b phosphotransferase gene--a. nidulans trpc terminator--puc19 (pcbhgod) vector was constructed in e. coli dh5alpha by pcr application and gene cloning methods. t. reesei qm9414 protoplast was transformed by t. reesei cbhi promo ...200616572845
protein kinase c (pkca) of aspergillus nidulans is involved in penicillin production.the biosynthesis of the beta-lactam antibiotic penicillin in the filamentous fungus aspergillus nidulans is catalyzed by three enzymes that are encoded by the acva, ipna, and aata genes. a variety of cis-acting dna elements and regulatory factors form a complex regulatory network controlling these beta-lactam biosynthesis genes. regulators involved include the ccaat-binding complex ancf and anbh1. anbh1 acts as a repressor of the penicillin biosynthesis gene aata. until now, however, little info ...200616598003
antimicrobial, wound healing and antioxidant activity of plagiochasma appendiculatum lehm. et lind.plagiochasma appendiculatum (aytoniaceae) of the order marchantiales is widely used in the form of paste ethnomedicinally by gaddi tribe in kangra valley for treating skin diseases. in this context, antimicrobical potential of plagiochasma appendiculatum against a wide range of microorganisms was studied. to validate the ethnotherapeutic claims of the plant in skin diseases, wound healing activity was studied, besides antioxidant activity to understand the mechanism of wound healing activity. th ...200616600543
microscopy reveals disease control through novel effects on fungal development: a case study with an early-generation benzophenone fungicide.the benzophenones are a new class of agricultural fungicides that demonstrate protectant, curative and eradicative/antisporulant activity against powdery mildews. the chemistry is represented in the marketplace by the fungicide metrafenone, recently introduced by basf and discussed in the following paper. the benzophenones show no evidence of acting by previously identified biochemical mechanisms, nor do they show cross-resistance with existing fungicides. the value of microscopy in elucidating ...200616602068
isolation of mutations that bypass the requirement of the septation initiation network for septum formation and conidiation in aspergillus nidulans.the kinase cascade of the septation initiation network (sin), first revealed in fission yeast, activates the contraction of the actomyosin ring, and plays an essential role in fungal septation. mob1p, an evolutionarily conserved sin protein, is associated with the most downstream kinase of this cascade in fission yeast. in this study, the moba gene encoding a homologous protein was isolated from the filamentous fungus aspergillus nidulans, whose mycelium is made of multinucleate cells. the moba ...200616624915
the region in a subunit of the aspergillus ccaat-binding protein similar to the hap4p-recruiting domain of saccharomyces cerevisiae hap5p is not essential for transcriptional enhancement.the ccaat-binding complex in aspergillus species, known as the hap complex, consists of at least three subunits, hapb, hapc, and hape. each hap subunit contains an evolutionarily conserved core domain. in this study, a series of the truncated gene, which encodes the hape subunit of aspergillus oryzae, was constructed to survey the regions essential for the transcriptional enhancement of fungal genes. it was revealed that the non-conserved regions and the conserved region similar to the hap4p rec ...200616636442
transcription analysis using high-density micro-arrays of aspergillus nidulans wild-type and crea mutant during growth on glucose or, we describe how the recently published aspergillus nidulans genome sequence [galagan, j.e., calvo, s.e., cuomo, c., li-jun, m., wortman, j.r., et al., 2005. sequencing of aspergillus nidulans and comparative analysis with a. fumigatus and a. oryzae. nature 438 (7071), 1105-1115] was used to design a high-density oligo array with probes for 3,278 selected genes using the febit geniom one array system. for this purpose, the program oligowiz ii was used to design 24,125 probes to cover the 3, ...200616698295
marker and promoter effects on heterologous expression in aspergillus study the effects of selection marker, promoter type, and copy number on heterologous expression in aspergillus nidulans, strains were constructed with single- and multicopy plasmid integrations bearing a reporter gene (lacz) under the control of either an inducible (alca) or constitutive (gpda) promoter and one of three aspergillus nutritional marker genes (argb, trpc, or niad). beta-galactosidase activity in the transformants varied over three orders of magnitude, with the majority of level ...200616699756
isolation, characterization, and disruption of dnr1, the area/nit-2-like nitrogen regulatory gene of the zoophilic dermatophyte, microsporum canis.a homolog of the major nitrogen regulatory genes area from aspergillus nidulans and nit-2 from neurospora crassa was isolated from the zoophilic dermatophyte, microsporum canis. this gene, dnr1, encodes a polypeptide of 761 amino acid residues containing a single zinc-finger dna-binding domain, which is almost identical in amino acid sequence to the zinc-finger domains of area and nit-2. the functional equivalence of dnr1 to area was demonstrated by complementation of an area loss-of-function mu ...200616702104
an extract of morinda citrifolia interferes with the serum-induced formation of filamentous structures in candida albicans and inhibits germination of aspergillus aqueous extract of morinda citrifolia was shown to interfere with the serum-induced morphological conversion of candida albicans from a cellular yeast to a filamentous form in vitro. the conversion of c. albicans from a cellular yeast to a filamentous form in vivo is associated with pathogenicity. no significant effect on growth in serum-free media was seen at the concentrations used to interfere with the morphological change. the same extract also inhibited the germination of apergillus nidu ...200616710899
transcriptional and bioinformatic analysis of the 56.8 kb dna region amplified in tandem repeats containing the penicillin gene cluster in penicillium chrysogenum.high penicillin-producing strains of penicillium chrysogenum contain 6-14 copies of the three clustered structural biosynthetic genes, pcbab, pcbc, and pende [barredo, j.l., díez, b., alvarez, e., martín, j.f., 1989. large amplification of a 35-kb dna fragment carrying two penicillin biosynthetic genes in high penicillin producing strains of penicillium chrysogenum. curr. genet. 16, 453-459; smith, d.j., bull, j.h., edwards, j., turner, g., 1989. amplification of the isopenicillin n synthetase g ...200616713314
genomic and experimental evidence for a potential sexual cycle in the pathogenic thermal dimorphic fungus penicillium marneffei.all meiotic genes (except hop1) and genes encoding putative pheromone processing enzymes, pheromone receptors and pheromone response pathways proteins in aspergillus fumigatus and aspergillus nidulans and a putative mat-1 alpha box mating-type gene were present in the penicillium marneffei genome. a putative mat-2 high-mobility group mating-type gene was amplified from a mat-1 alpha box mating-type gene-negative p. marneffei strain. among 37 p. marneffei patient strains, mat-1 alpha box and mat- ...200616714021
heterotrimeric g protein signaling and rgss in aspergillus nidulans.heterotrimeric g proteins (g proteins) are conserved in all eukaryotes and are crucial components sensing and relaying external cues into the cells to elicit appropriate physiological and biochemical responses. basic units of the heterotrimeric g protein signaling system include a g protein-coupled receptor (gpcr), a g protein composed of alpha, beta, and gamma subunits, and variety of effectors. sequential sensitization and activation of these g protein elements translates external signals into ...200616728950
the distribution and evolutionary history of the prp8 intein.we recently described a mini-intein in the prp8 gene of a strain of the basidiomycete cryptococcus neoformans, an important fungal pathogen of humans. this was the second described intein in the nuclear genome of any eukaryote; the first nuclear encoded intein was found in the vma gene of several saccharomycete yeasts. the evolution of eukaryote inteins is not well understood. in this report we describe additional prp8 inteins (bringing the total of these to over 20). we compare and contrast the ...200616737526
a mammalian nudc-like protein essential for dynein stability and cell viability.cytoplasmic dynein, a minus-end-directed microtubule motor, has been implicated in many fundamental cellular processes; however, little is known regarding the underlying molecular machinery that regulates its stability. in aspergillus nidulans, nuclear distribution gene c (nudc) has been implicated in the regulation of dynein-mediated nuclear migration. here, we characterize a previously undescribed mammalian nudc-like protein (nudcl). the expression and phosphorylation of nudcl are increased du ...200616754861
the fumitremorgin gene cluster of aspergillus fumigatus: identification of a gene encoding brevianamide f synthetase.a gene encoding a putative dimodular nonribosomal peptide synthetase (nrps) was identified within a gene cluster of aspergillus fumigatus, a species reported to produce fumitremorgins and other prenylated alkaloids. the gene was deleted and overexpressed in the genome reference strain af293, and was also expressed in the naïve host aspergillus nidulans, which lacks the equivalent gene cluster. while neither fumitremorgins nor the dipeptide brevianamide f (cyclo-l-trp-l-pro), an early intermediat ...200616755625
functional characterization of aspergillus nidulans homologues of saccharomyces cerevisiae spa2 and bud6.the importance of polarized growth for fungi has elicited significant effort directed at better understanding underlying mechanisms of polarization, with a focus on yeast systems. at sites of tip growth, multiple protein complexes assemble and coordinate to ensure that incoming building material reaches the appropriate destination sites, and polarized growth is maintained. one of these complexes is the polarisome that consists of spa2, bud6, pea2, and bni1 in saccharomyces cerevisiae. filamentou ...200616757736
[diagnosis and treatment of aspergillosis in the patients with chronic granulomatous disease].chronic granulomatous disease is a rare defect of phagocytosis. increased susceptibility to infections is limited to catalase positive bacteria and fungi. aspergillus spp was reported as the increased clinical problem and the main cause of the deaths.200616758737
outdoor environmental levels of aspergillus spp. conidia over a wide geographical area.unfortunately, little information is available on the 'normal' air and water load of aspergillus spores and their seasonal changes. we describe the air and water load of aspergillus spores across the province of madrid (spain). we collected samples of air and water (332 samples of air and 148 of water) from selected points and taps (urban and rural environment) in summer, autumn, winter and spring. temperature, wind speed and humidity at each point were obtained. we collected a total of 369 aspe ...200616772229
the ambient ph response rim pathway in yarrowia lipolytica: identification of ylrim9 and characterization of its role in dimorphism.yarrowia lipolytica is a dimorphic fungus that secretes either an acidic or an alkaline protease depending on the environmental ph. previous results have indicated that secretion of the alkaline protease is under control of the ph signaling pal/rim pathway originally described in aspergillus nidulans. several y. lipolytica mutants defective in some rim components of this pathway have been previously isolated and the rim genes characterized. in the present study, y. lipolytica rim9 (pali) gene (y ...200616775780
reducing the cost of resistance; experimental evolution in the filamentous fungus aspergillus nidulans.we have studied compensatory evolution in a fludioxonil resistant mutant of the filamentous fungus aspergillus nidulans. in an evolution experiment lasting for 27 weeks (about 3000 cell cycles) 35 parallel strains of this mutant evolved in three different environmental conditions. our results show a severe cost of resistance (56%) in the absence of fludioxonil and in all conditions the mutant strain was able to restore fitness without loss of the resistance. in several cases, the evolved strain ...200616780512
the zn(ii)2cys6 putative transcription factor nosa controls fruiting body formation in aspergillus nidulans.the filamentous fungus aspergillus nidulans reproduces asexually with conidiospores and sexually with ascospores, both of which are the result of complex morphogenetic pathways. the developmental decisions for both ways of reproduction largely depend on the action of stage-specific transcription factors. here we have characterized the putative zn(ii)(2)cys(6) transcription factor nosa (number of sexual spores), a protein of 675 aa, which shares 44% sequence identity to pro1 from sordaria macrosp ...200616780567
consecutive gene deletions in aspergillus nidulans: application of the cre/loxp system.the ability to perform multiple gene deletions is an important tool for conducting functional genomics. we report the development of a sequential gene deletion protocol for the filamentous fungus aspergillus nidulans using the cre/loxp recombinase system of bacteriophage p1. a recyclable genetic marker has been constructed by incorporating loxp direct repeats either side of the neurospora crassa pyr-4 gene (encodes orotidine 5'-monophosphate decarboxylase) which is able to complement the a. nidu ...200616783565
chemical characterization and quantification of siderophores produced by marine and terrestrial aspergilli.ten aspergilli (five each from marine and terrestrial habitats) were screened for siderophore production. all test isolates produced siderophores as indicated by a positive reaction in the fecl(3) test, chrome azurol sulphonate assay, and chrome azurol sulphonate agar plate test. further, the test isolates were compared for their siderophore production potential and chemical characteristics. examination of the chemical nature of the siderophores revealed that all test isolates produced hydroxama ...200616788730
a phosphoglucose isomerase mutant in aspergillus nidulans is defective in hyphal polarity and conidiation.upon germination aspergillus nidulans swom1 exhibits abnormal development by extending a primary germ tube that quickly reverts to isotropic growth and results in an enlarged, swollen apex with pronounced wall thickenings. apical lysis occurs in 38% of the germlings. a point mutation in the an6037.3 gene encoding the only phosphoglucose isomerase in a. nidulans is responsible for the defect. loss of polarity is bypassed when glucose is replaced with alternate carbon sources but in all cases the ...200616798030
lipid signaling in pathogenic fungi.recent studies have highlighted the importance of lipid signaling molecules in the development and pathogenicity of clinically important fungi. in cryptococcus neoformans, sphingolipid-derived diacylglycerol has been shown to induce the transcription of the putative virulence factor app1, which inhibits the phagocytosis of fungal cells by alveolar macrophages, as well as to activate the protein kinase c pkc1, which promotes cell-wall stability and increased melanin production. in candida albican ...200616798065
a phe389leu substitution in erga confers terbinafine resistance in aspergillus fumigatus.replacement of phenylalanine with leucine at position 391 in squalene epoxidase was identified as being responsible for terbinafine resistance in mutants of aspergillus nidulans. the equivalent mutation was engineered into the erga gene of aspergillus fumigatus, resulting in an f389l substitution that also conferred resistance to this pathogenic mold.200616801438
mutants of aspergillus nidulans affected in asexual development. 200616809845
structure, organization, and transcriptional regulation of a family of copper radical oxidase genes in the lignin-degrading basidiomycete phanerochaete chrysosporium.the white rot basidiomycete phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the h2o2-generating copper radical oxidase, glyoxal oxidase (glx). preliminary analysis of the p. chrysosporium draft genome had identified six sequences with significant similarity to glx and designated cro1 through cro6. the predicted mature protein sequences diverge substantially fr ...200616820482
use of laccase as a novel, versatile reporter system in filamentous fungi.laccases are copper-containing enzymes which oxidize phenolic substrates and transfer the electrons to oxygen. many filamentous fungi contain several laccase-encoding genes, but their biological roles are mostly not well understood. the main interest in laccases in biotechnology is their potential to be used to detoxify phenolic substances. we report here on a novel application of laccases as a reporter system in fungi. we purified a laccase enzyme from the ligno-cellulolytic ascomycete stachybo ...200616820501
the aspergillus nidulans f-box protein grra links scf activity to meiosis.cellular differentiation relies on precise and controlled means of gene expression that act on several levels to ensure a flexible and defined spatio-temporal expression of a given gene product. in our aim to identify transcripts enriched during fruiting body formation of the homothallic ascomycete aspergillus (emericella) nidulans, the grra gene could be identified in a negative subtraction hybridization screening procedure. it encodes a protein similar to fungal f-box proteins, which function ...200616824096
interactions between iron availability, aluminium toxicity and fungal siderophores.the influence of iron, aluminium and of the combined application of both metals on microbial biomass and production of siderophores by three fungi (aspergillus nidulans, neurospora crassa and hymenoscyphus ericae) were investigated. all three species showed a strong iron regulation and al-sensitivity of siderophore biosynthesis although several differences remained species dependent. inhibitory effects of fe and al on siderophore-production were additive and the higher binding capacity of sidero ...200616841246
development and application of a suite of polysaccharide-degrading enzymes for analyzing plant cell facilitate analysis of plant cell wall polysaccharide structure and composition, we cloned 74 genes encoding polysaccharide-degrading enzymes from aspergillus nidulans, aspergillus fumigatus, and neurospora crassa and expressed the genes as secreted proteins with c-terminal myc and 6x his tags. most of the recombinant enzymes were active in enzyme assays, and optima for ph and temperature were established. a subset of the enzymes was used to fragment polysaccharides from the irregular xylem 9 ...200616844780
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