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mammalian n-acetylglutamate synthase.n-acetylglutamate synthase (nags, e.c. 2.3.1.1) is a mitochondrial enzyme that catalyzes the formation of n-acetylglutamate (nag), an essential allosteric activator of carbamylphosphate synthetase i (cpsi). the mouse and human nags genes have been identified based on similarity to regions of nags from neurospora crassa and cloned from liver cdna libraries. these genes were shown to complement an arga- (nags) deficient escherichia coli strain, and enzymatic activity of the proteins was confirmed ...200415050968
in vivo levels of s-adenosylmethionine modulate c:g to t:a mutations associated with repeat-induced point mutation in neurospora crassa.in neurospora crassa, the mutagenic process termed repeat-induced point mutation (rip) inactivates duplicated dna sequences during the sexual cycle by the introduction of c:g to t:a transition mutations. in this work, we have used a collection of n. crassa strains exhibiting a wide range of cellular levels of s-adenosylmethionine (adomet), the universal donor of methyl groups, to explore whether frequencies of rip are dependent on the cellular levels of this metabolite. mutant strains met-7 and ...200415063139
identification and characterization of a nitrate transporter gene in neurospora crassa.the neurospora crassa genome database was searched for sequence similarity to crna, a nitrate transporter in aspergillus nidulans. a 3.9-kb fragment (contig 3.416, subsequence 183190-187090) was cloned by pcr. the gene coding for this nitrate transporter was termed nit-10. the nit-10 gene specifies a predicted polypeptide containing 541 amino acids with a molecular mass of 57 kda. in contrast to crna, which is clustered together with niad, encoding nitrate reductase, and niia, encoding nitrite r ...200415068336
role of a mitogen-activated protein kinase pathway during conidial germination and hyphal fusion in neurospora crassa.mitogen-activated protein (map) kinase signaling pathways are ubiquitous and evolutionarily conserved in eukaryotic organisms. map kinase pathways are composed of a map kinase, a map kinase kinase, and a map kinase kinase kinase; activation is regulated by sequential phosphorylation. components of three map kinase pathways have been identified by genome sequence analysis in the filamentous fungus neurospora crassa. one of the predicted map kinases in n. crassa, mak-2, shows similarity to fus3p a ...200415075265
[advances in the molecular mechanism of rna interference].this paper reviews the latest development of rna interference(rnai). rna interference is the process of sequence-specific degradation of homologous mrna triggered by double-stranded rna. as a technically simple and an effective genetic tool which can exert effect on the expression of gene and substitute for gene knock-out technique in some degree, rnai phenomena have been broadly validated in diverse model organisms such as caenorhabditis elegans, drosophila melanogaster, arabidopsis thaliana an ...200415079801
the neurospora crassa cfp promoter drives a carbon source-dependent expression of transgenes in filamentous fungi.the objective of the present study was to determine the potential of promoter sequences from the cfp gene of neurospora crassa to drive the expression of transgenes in filamentous fungi.200415139917
identification of cryptochrome dash from vertebrates.a new type of cryptochrome, cry-dash, has been recently identified. the cry-dash proteins constitute the fifth subfamily of the photolyase/cryptochrome family. cry-dashs have been identified from synechocystis sp. pcc 6803, vibrio cholerae, and arabidopsis thaliana. the synechocystis cry-dash was the first cryptochrome identified from bacteria, and its biochemical features and tertiary structure have been extensively investigated. to determine how broadly the subfamily is distributed within livi ...200415147276
alternative splicing of transcripts of the transposon restless is maintained in the foreign host neurospora crassa and can be modified by introducing mutations at the 5' and 3' splice sites.the primary transcript of the transposon restless from tolypocladium inflatum undergoes an unusual mechanism of alternative splicing by employing either of two 3' "cag" splice sites. these are separated by only four nucleotides, thus generating two different splice products, which differ in their coding capacity. to analyse whether this alternative splicing occurs in its natural host exclusively, we introduced the transposon into the heterologous host neurospora crassa. in addition to the wild - ...200415148624
calcium measurement in living filamentous fungi expressing codon-optimized aequorin.calcium signalling is little understood in filamentous fungi largely because easy and routine methods for calcium measurement in living hyphae have previously been unavailable. we have developed the recombinant aequorin method for this purpose. high levels of aequorin expression were obtained in neurospora crassa, aspergillus niger and aspergillus awamori by codon optimization of the aequorin gene. three external stimuli (mechanical perturbation, hypo-osmotic shock and high external calcium) wer ...200415165245
altering a gene involved in nuclear distribution increases the repeat-induced point mutation process in the fungus podospora anserina.repeat-induced point mutation (rip) is a homology-dependent gene-silencing mechanism that introduces c:g-to-t:a transitions in duplicated dna segments. cis-duplicated sequences can also be affected by another mechanism called premeiotic recombination (pr). both are active over the sexual cycle of some filamentous fungi, e.g., neurospora crassa and podospora anserina. during the sexual cycle, several developmental steps require precise nuclear movement and positioning, but connections between rip ...200415166143
the bafilomycin/concanamycin binding site in subunit c of the v-atpases from neurospora crassa and saccharomyces cerevisiae.the vacuolar h+-atpase is inhibited with high specificity and potency by bafilomycin and concanamycin, macrolide antibiotics with similar structures. we previously reported that mutation at three residues in subunit c of the vacuolar atpase from neurospora crassa conferred strong resistance to bafilomycin but little or no resistance to concanamycin (bowman, b. j., and bowman, e. j. (2002) j. biol. chem. 277, 3965-3972). we have identified additional mutated sites in subunit c that confer resista ...200415180988
bioremediation of 60co from simulated spent decontamination solutions.bioremediation of 60co from simulated spent decontamination solutions by utilizing different biomass of (neurospora crassa, trichoderma viridae, mucor recemosus, rhizopus chinensis, penicillium citrinum, aspergillus niger and, aspergillus flavus) fungi is reported. various fungal species were screened to evaluate their potential for removing cobalt from very low concentrations (0.03-0.16 microm) in presence of a high background of iron (9.33 mm) and nickel (0.93 mm) complexed with edta (10.3 mm) ...200415207568
the pho80-like cyclin of aspergillus nidulans regulates development independently of its role in phosphate acquisition.in saccharomyces cerevisiae, phosphate acquisition enzymes are regulated by a cyclin-dependent kinase (pho85), a cyclin (pho80), the cyclin-dependent kinase inhibitor pho81, and the helix-loop-helix transcription factor pho4 (the pho system). previous studies in aspergillus nidulans indicate that a pho85-like kinase, phoa, does not regulate the classic pho system but regulates development in a phosphate-dependent manner. a pho80-like cyclin has now been isolated through its interaction with phoa ...200415247298
functional characterization of the conserved "glk" motif in mitochondrial porin from neurospora crassa.mitochondrial porin facilitates the diffusion of small hydrophilic molecules across the mitochondrial outer membrane. despite low sequence similarity among porins from different species, a "glycine-leucine-lysine" (glk) motif is conserved in mitochondrial and neisseria porins. to investigate the possible roles of these conserved residues, including their hypothesized participation in atp binding by the protein, we replaced the lysine residue of the glk motif of neurospora crassa porin with gluta ...200015254370
alleles of the hotspot cog are codominant in effect on recombination in the his-3 region of neurospora.there are two naturally occurring functional alleles of the recombination hotspot cog, which is located 3.5 kb from the his-3 locus of neurospora crassa. the presence of the cog+ allele in a cross significantly increases recombination in the his-3 region compared to a cross homozygous for the cog allele. data obtained shortly after discovery of cog+ suggested that it was fully dominant to cog. however, a dominant cog+ conflicts with observations of hotspots in saccharomyces cerevisiae and schizo ...200415280230
a comparative genomic analysis of the calcium signaling machinery in neurospora crassa, magnaporthe grisea, and saccharomyces cerevisiae.a large number of ca2+ -signaling proteins have been previously identified and characterized in saccharomyces cerevisiae but relatively few have been discovered in filamentous fungi. in this study, a detailed, comparative genomic analysis of ca2+ -signaling proteins in neurospora crassa, magnaporthe grisea, and s. cerevisiae has been made. our blast analysis identified 48, 42, and 40 ca2+ -signaling proteins in n. crassa, m. grisea, and s. cerevisiae, respectively. in n. crassa, m. grisea, and s ...200415288019
highly efficient gene replacements in neurospora strains deficient for nonhomologous end-joining.gene disruption and overexpression play central roles in the analysis of gene function. homologous recombination is, in principle, the most efficient method of disrupting, modifying, or replacing a target gene. although homologous integration of exogenous dna into the genome occurs readily in saccharomyces cerevisiae, it is rare in many other organisms. we identified and disrupted neurospora crassa genes homologous to human ku70 and ku80, which encode proteins that function in nonhomologous end- ...200415299145
crystal structure of 3-carboxy-cis,cis-muconate lactonizing enzyme from pseudomonas putida, a fumarase class ii type cycloisomerase: enzyme evolution in parallel pathways.3-carboxy-cis,cis-muconate lactonizing enzymes (cmles), the key enzymes in the protocatechuate branch of the beta-ketoadipate pathway in microorganisms, catalyze the conversion of 3-carboxy-cis,cis-muconate to muconolactones. we have determined the crystal structure of the prokaryotic pseudomonas putida cmle (ppcmle) at 2.6 a resolution. ppcmle is a homotetramer and belongs to the fumarase class ii superfamily. the active site of ppcmle is formed largely by three regions, which are moderately co ...200415301541
one of the two dicer-like proteins in the filamentous fungi magnaporthe oryzae genome is responsible for hairpin rna-triggered rna silencing and related small interfering rna accumulation.dicer is a ribonuclease iii-like enzyme playing a key role in the rna silencing pathway. genome sequencing projects have demonstrated that eukaryotic genomes vary in the numbers of dicer-like (dcl) proteins from one (human) to four (arabidopsis). two dcl genes, mdl-1 and -2 (magnaporthe dicer-like-1 and -2) have been identified in the genome of the filamentous fungus magnaporthe oryzae. here we show that the knockout of mdl-2 drastically impaired gene silencing of enhanced green fluorescence pro ...200415304480
human mitochondrial complex i assembles through the combination of evolutionary conserved modules: a framework to interpret complex i deficiencies.with 46 subunits, human mitochondrial complex i is the largest enzyme of the oxidative phosphorylation system. we have studied the assembly of complex i in cultured human cells. this will provide essential information about the nature of complex i deficiencies and will enhance our understanding of mitochondrial disease mechanisms. we have found that 143b206 rho zero cells, not containing mitochondrial dna, are still able to form complex i subcomplexes. to further address the nature of these subc ...200415317750
unique biosynthesis of dehydroquinic acid?a search of the genomic sequences of the thermophilic microorganisms aquifex aeolicus, archaeoglobus fulgidus, methanobacterium thermoautotrophicum, and methanococcus jannaschii for the first seven enzymes (arog, b, d, e, k, a, and c ) involved in the shikimic acid biosynthetic pathway reveal two key enzymes are missing. the first enzyme in the pathway, 3-deoxy-d-arabino-heptulosonic acid 7-phosphate synthase (arog) and the second enzyme in the pathway, 5-dehydroquinic acid synthase (arob) are " ...200415381397
nanocapsules: coating for living cells.one of the most promising tools for future applications in science and medicine is the use of nanotechnologies. especially self-assembly systems, e.g., polyelectrolyte (pe) capsules prepared by means of the layer-by-layer technique with tailored properties, fulfill the requirements for nano-organized systems in a satisfactory manner. the nano-organized shells are suitable as coating for living cells or artificial tissue to prevent immune response. with these shells, material can be delivered to ...200415382641
studies on the formation of invertase by neurospora crassa. 195015419292
turgor regulation in hyphal organisms.turgor regulation in two saprophytic hyphal organisms was examined directly with the pressure probe technique. the ascomycete neurospora crassa, a terrestrial fungi, regulates turgor after hyperosmotic treatments when growing in a minimal medium containing k(+), mg(2+), ca(2+), cl(-), and sucrose. turgor recovery by n. crassa after hyperosmotic treatment is concurrent with changes in ion transport: hyperpolarization of the plasma membrane potential and a decline in transmembrane ion conductance. ...200415465389
introns and splicing elements of five diverse fungi.genomic sequences and expressed sequence tag data for a diverse group of fungi (saccharomyces cerevisiae, schizosaccharomyces pombe, aspergillus nidulans, neurospora crassa, and cryptococcus neoformans) provided the opportunity to accurately characterize conserved intronic elements. an examination of large intron data sets revealed that fungal introns in general are short, that 98% or more of them belong to the canonical splice site (ss) class (5'gu...ag3'), and that they have polypyrimidine tra ...200415470237
identification of the protein binding region of s-trityl-l-cysteine, a new potent inhibitor of the mitotic kinesin eg5.human eg5, a mitotic motor of the kinesin superfamily, is involved in the formation and maintenance of the mitotic spindle. the recent discovery of small molecules that inhibit hseg5 by binding to its catalytic motor domain leading to mitotic arrest has attracted more interest in eg5 as a potential anticancer drug target. we have used hydrogen-deuterium exchange mass spectrometry and directed mutagenesis to identify the secondary structure elements that form the binding sites of new eg5 inhibito ...200415476401
solution structure of cu6 metallothionein from the fungus neurospora crassa.the 3d-solution structure of neurospora crassa cu(6)-metallothionein (ncmt) polypeptide backbone was determined using homonuclear, multidimensional (1)h-nmr spectroscopy. it represents a new metallothionein (mt) fold with a protein chain where the n-terminal half is left-handed and the c-terminal half right-handedly folded around a copper(i)-sulfur cluster. as seen with other mts, the protein lacks definable secondary structural elements; however, the polypeptide fold is unique. the metal coordi ...200415511227
metabolic highways of neurospora crassa revisited.this chapter describes the metabolic pathways for neurospora crassa in the biosynthesis of amino acids, purines, pyrimidines, vitamins, and cofactors, and for glycolysis, the tca and glyoxylate cycles and the initial stages of the pentose phosphate pathway. for each step in metabolism, the gene or genes within the genome sequence of the species is identified, correlations are made with previously identified genes, and new gene designations are assigned to others. for each gene, details given are ...200415522735
a phylogenomic approach to reconstructing the diversification of serine proteases in fungi.using a phylogenomic approach with 10 fungi of very different virulence and habitat, we determined that there was substantial diversification of subtilase-type proteases early in ascomycete history (with subsequent loss in many lineages) but with no comparable diversification of trypsins. patterns of intron loss and the degree of divergence between paralogues demonstrated that the proliferation of proteinase k subtilases and subtilisin type subtilases seen in pathogenic ascomycetes (metarhizium ...200415525405
acfkh1, a novel member of the forkhead family, associates with the rfx transcription factor cpcr1 in the cephalosporin c-producing fungus acremonium chrysogenum.in the filamentous fungus acremonium chrysogenum, a complex regulatory network of transcription factors controls the expression of at least seven cephalosporin c biosynthesis genes. the rfx transcription factor cpcr1 binds to regulatory sequences in the promoter region of cephalosporin c biosynthesis genes, and is involved in the transcriptional regulation of the pcbc gene which encodes isopenicillin n synthase. in this study, we used cpcr1 in a yeast two-hybrid screen to identify potential prot ...200415527986
blr-1 and blr-2, key regulatory elements of photoconidiation and mycelial growth in trichoderma atroviride.in fungi, phototropism, the induction of carotenogenesis and reproductive structures, and resetting of the circadian rhythm are controlled by blue light. trichoderma atroviride, a fungus used in biological control, sporulates in a synchronized manner following a brief pulse of blue light. due to its apparent simplicity, this response was chosen for pursuing photoreceptor isolation. two genes were cloned, blue-light regulators 1 and 2 (blr-1 and blr-2), similar to the neurospora crassa white-coll ...200415528646
transcriptional response to glucose starvation and functional analysis of a glucose transporter of neurospora crassa.the response to glucose availability in neurospora crassa was characterized by measuring transcript levels of 1335 genes represented on a cdna microarray. we found that 19% of the 1335 genes were regulated at least twofold in response to glucose deprivation. several sugar transporter homologs were found to be regulated by glucose. functional analysis of one of these, hgt-1, indicates that it encodes a high-affinity glucose transporter. comparing n. crassa profiling data with the published diauxi ...200415531214
conservation and evolution of cis-regulatory systems in ascomycete fungi.relatively little is known about the mechanisms through which gene expression regulation evolves. to investigate this, we systematically explored the conservation of regulatory networks in fungi by examining the cis-regulatory elements that govern the expression of coregulated genes. we first identified groups of coregulated saccharomyces cerevisiae genes enriched for genes with known upstream or downstream cis-regulatory sequences. reasoning that many of these gene groups are coregulated in rel ...200415534694
neurospora crassa cypbp37: a cytosolic stress protein that is able to replace yeast thi4p function in the synthesis of vitamin b1.recently, we identified cypbp37 of neurospora crassa as a binding partner of cyclophilin41. cypbp37 function had not yet been described, although orthologs in other organisms have been implicated in the biosynthesis of the thiazole moiety of thiamine (vitamin b1) and/or stress-related pathways. here, cypbp37 is characterized as an abundant cytosolic protein with a functional nad-binding site. saccharomyces cerevisiae mutants lacking thi4p (the cypbp37 ortholog) are auxotrophic for vitamin b1 (th ...200415544818
rna silencing in aspergillus nidulans is independent of rna-dependent rna polymerases.the versatility of rna-dependent rna polymerases (rdrps) in eukaryotic gene silencing is perhaps best illustrated in the kingdom fungi. biochemical and genetic studies of schizosaccharomyces pombe and neurospora crassa show that these types of enzymes are involved in a number of fundamental gene-silencing processes, including heterochromatin regulation and rna silencing in s. pombe and meiotic silencing and rna silencing in n. crassa. here we show that aspergillus nidulans, another model fungus, ...200515545645
survey of simple sequence repeats in completed fungal genomes.the use of simple sequence repeats or microsatellites as genetic markers has become very popular because of their abundance and length variation between different individuals. ssrs are tandem repeat units of 1 to 6 base pairs that are found abundantly in many prokaryotic and eukaryotic genomes. this is the first study examining and comparing ssrs in completely sequenced fungal genomes. we analyzed and compared the occurrences, relative abundance, relative density, most common, and longest ssrs i ...200515563717
pcmtr, an aromatic and neutral aliphatic amino acid permease of penicillium chrysogenum.the gene encoding an aromatic and neutral aliphatic amino acid permease of penicillium chrysogenum was cloned, functionally expressed and characterized in saccharomyces cerevisiae m4276. the permease, designated pcmtr, is structurally and functionally homologous to mtr of neurospora crassa, and unrelated to the amino acid permease (aap) family which includes most amino acid permeases in fungi. database searches of completed fungal genome sequences reveal that mtr type permeases are not widely di ...200415581852
involvement of a flavosemiquinone in the enzymatic oxidation of nitroalkanes catalyzed by 2-nitropropane dioxygenase.2-nitropropane dioxygenase (ec 1.13.11.32) catalyzes the oxidation of nitroalkanes into their corresponding carbonyl compounds and nitrite. in this study, the ncd-2 gene encoding for the enzyme in neurospora crassa was cloned, expressed in escherichia coli, and the resulting enzyme was purified. size exclusion chromatography, heat denaturation, and mass spectroscopic analyses showed that 2-nitropropane dioxygenase is a homodimer of 80 kda, containing a mole of non-covalently bound fmn per mole o ...200415582992
in vitro and in vivo analyses of a phe/tyr switch controlling product specificity of histone lysine methyltransferases.the functional significance of mono-, di-, and tri-methylation of lysine residues within histone proteins is under investigation. evidence from several model organisms suggests that different methylated states of h3 lys(9) (h3k9) are generated by specific histone methyltransferases (mtases) to mark distinct types of silent chromatin. sequence alignment of all histone lysine mtases with known product specificity suggested that a key residue in the active site determines how many methyl groups the ...200415590646
gene discovery and gene expression in the rice blast fungus, magnaporthe grisea: analysis of expressed sequence tags.over 28,000 expressed sequence tags (ests) were produced from cdna libraries representing a variety of growth conditions and cell types. several magnaporthe grisea strains were used to produce the libraries, including a nonpathogenic strain bearing a mutation in the pmk1 mitogen-activated protein kinase. approximately 23,000 of the ests could be clustered into 3,050 contigs, leaving 5,127 singleton sequences. the estimate of 8,177 unique sequences indicates that over half of the genes of the fun ...200415597739
the splicing of yeast mitochondrial group i and group ii introns requires a dead-box protein with rna chaperone function.group i and ii introns self-splice in vitro, but require proteins for efficient splicing in vivo, to stabilize the catalytically active rna structure. recent studies showed that the splicing of some neurospora crassa mitochondrial group i introns additionally requires a dead-box protein, cyt-19, which acts as an rna chaperone to resolve nonnative structures formed during rna folding. here we show that, in saccharomyces cerevisiae mitochondria, a related dead-box protein, mss116p, is required for ...200415618406
a recq gene homolog from the basidiomycetous mushroom lentinula edodes: sequence analysis and expression.we cloned and sequenced a recq gene homolog from the basidiomycetous mushroom lentinula edodes (le.). this gene, named le.recq, was found to have a coding capacity of 945 amino acids (aa) and be interrupted by 11 small introns. the deduced le.recq protein was clearly smaller than other fungal recq proteins such as neurospora crassa qde3 (1955 aa), schizosaccharomyces pombe rqh1 (1328 aa), and saccharomyces cerevisiae sgs1 (1447 aa). it exhibited the highest homology to the arabidopsis thaliana r ...200415618631
gene silencing pathway rna-dependent rna polymerase of neurospora crassa: yeast expression and crystallization of selenomethionated qde-1 protein.the rna-dependent rna polymerase, qde-1, is a component of the rna silencing pathway in neurospora crassa. the enzymatically active carboxy-terminal fragment qde-1 deltan has been expressed in saccharomyces cerevisiae in the presence and absence of selenomethionine (semet). the level of semet incorporation was estimated by mass spectrometry to be approximately 98%. both native and semet proteins were crystallized in space group p2(1) with unit cell parameters a=101.2, b=122.5, c=114.4a, beta=108 ...200515629662
silencing of unpaired chromatin and histone h2a ubiquitination in mammalian meiosis.during meiotic prophase in male mammals, the x and y chromosomes are incorporated in the xy body. this heterochromatic body is transcriptionally silenced and marked by increased ubiquitination of histone h2a. this led us to investigate the relationship between histone h2a ubiquitination and chromatin silencing in more detail. first, we found that ubiquitinated h2a also marks the silenced x chromosome of the barr body in female somatic cells. next, we studied a possible relationship between h2a u ...200515657431
the cot1 homologue cpcot1 regulates polar growth and branching and is essential for pathogenicity in claviceps purpurea.claviceps purpurea, the ergot fungus, is a common grass pathogen attacking exclusively young ovaries. its pathogenic development involves an early phase of directed growth (with strictly suppressed branching) towards the floral vascular tissue. since ser/thr protein kinases of the ndr family have been shown to be involved in polar growth and branching in fungi, we have analyzed a c. purpurea homologue of the neurospora crassa cot-1 gene, cpcot1. it encodes a functional homologue of cot1 since it ...200415670709
gnn is a self-glucosylating protein involved in the initiation step of glycogen biosynthesis in neurospora crassa.the initiation of glycogen synthesis requires the protein glycogenin, which incorporates glucose residues through a self-glucosylation reaction, and then acts as substrate for chain elongation by glycogen synthase and branching enzyme. numerous sequences of glycogenin-like proteins are available in the databases but the enzymes from mammalian skeletal muscle and from saccharomyces cerevisiae are the best characterized. we report the isolation of a cdna from the fungus neurospora crassa, which en ...200515680913
the heterotrimeric g-protein subunits gng-1 and gnb-1 form a gbetagamma dimer required for normal female fertility, asexual development, and galpha protein levels in neurospora crassa.we have identified a gene encoding a heterotrimeric g protein gamma subunit, gng-1, from the filamentous fungus neurospora crassa. gng-1 possesses a gene structure similar to that of mammalian ggamma genes, consisting of three exons and two introns, with introns present in both the open reading frame and 5'-untranslated region. the gng-1 amino acid sequence displays high identity to predicted ggamma subunits from other filamentous fungi, including giberella zeae, cryphonectria parasitica, tricho ...200515701799
a two-component histidine kinase of the rice blast fungus is involved in osmotic stress response and fungicide action.we isolated and characterized a histidine kinase gene (hik1) from the rice blast fungus, pyricularia oryzae (magnaporthe grisea). the deduced amino acid sequence of hik1 showed highest similarity (85.7%) to a hybrid-type histidine kinase, os-1/nik-1 of neurospora crassa. disruption of hik1 caused no defect in cell growth on normal media and in pathogenicity to rice plants. the deltahik1 strain acquired resistance to three groups of fungicides (phenylpyrroles, dicarboximides, and aromatic hydroca ...200515707841
heterologous expression, purification, and characterization of a highly active xylose reductase from neurospora crassa.a xylose reductase (xr) gene was identified from the neurospora crassa whole-genome sequence, expressed heterologously in escherichia coli, and purified as a his6-tagged fusion in high yield. this enzyme is one of the most active xrs thus far characterized and may be used for the in vitro production of xylitol.200515746370
light controls growth and development via a conserved pathway in the fungal kingdom.light inhibits mating and haploid fruiting of the human fungal pathogen cryptococcus neoformans, but the mechanisms involved were unknown. two genes controlling light responses were discovered through candidate gene and insertional mutagenesis approaches. deletion of candidate genes encoding a predicted opsin or phytochrome had no effect on mating, while strains mutated in the white collar 1 homolog gene bwc1 mated equally well in the light or the dark. the predicted bwc1 protein shares identity ...200515760278
functional and structural analysis of catalase oxidized by singlet oxygen.purified catalase-1 (cat-1) from neurospora crassa asexual spores is oxidized by singlet oxygen giving rise to active enzyme forms with different electrophoretic mobility. these enzyme forms are detected in vivo under stress conditions and during development at the start of the asexual morphogenetic transitions. cat-1 heme b is oxidized to heme d by singlet oxygen. here, we describe functional and structural comparisons of the non-oxidized enzyme with the fully oxidized one. using a broad h(2)o( ...200515760714
characterization of mutations in the two-component histidine kinase gene abnik1 from alternaria brassicicola that confer high dicarboximide and phenylpyrrole resistance.highly iprodione- and fludioxonil-resistant field and laboratory isolates of a. brassicicola were found to be either moderately sensitive or tolerant to osmotic stress. abnik1, a two-component histidine kinase gene, was isolated from a fungicide-sensitive strain. the predicted protein possessed the six tandem amino acid repeats at the n-terminal end, which is a landmark of osmosensor histidine kinases from filamentous fungi. a comparison of the nucleic acid sequences of the abnik1 gene from fung ...200515765227
fluffy, the major regulator of conidiation in neurospora crassa, directly activates a developmentally regulated hydrophobin gene.the fluffy (fl) gene of neurospora crassa is required for asexual sporulation and encodes an 88 kda polypeptide containing a typical fungal zn2cys6 dna-binding motif. identification of genes regulated by fl will provide insight into how fungi regulate growth during morphogenesis. as a step towards identifying the target genes on which fl may act, we sought to define target sequences to which the fl protein binds. the dna binding domain of fl was expressed in escherichia coli as a fusion with glu ...200515773996
novel g-protein-coupled receptor-like proteins in the plant pathogenic fungus magnaporthe grisea.the g-protein-coupled receptors (gpcrs) are one of the largest protein families in human and other animal genomes, but no more than 10 gpcrs have been characterized in fungi. do fungi contain only this handful or are there more receptors to be discovered? we asked this question using the recently sequenced genome of the fungal plant pathogen magnaporthe grisea.200515774025
purification and partial characterization of a paracoccidioides brasiliensis protein with capacity to bind to extracellular matrix proteins.microorganisms adhere to extracellular matrix proteins by means of their own surface molecules. paracoccidioides brasiliensis conidia have been shown to be capable of interacting with extracellular matrix proteins. we aimed at determining the presence of fungal proteins that could interact with extracellular matrix protein and, if found, attempt their purification and characterization. various extracts were prepared from p. brasiliensis mycelial and yeast cultures (total homogenates, beta-mercap ...200515784595
genes of the thymidine salvage pathway: thymine-7-hydroxylase from a rhodotorula glutinis cdna library and iso-orotate decarboxylase from neurospora crassa.genes for two enzymes in the thymidine salvage pathway, thymine-7-hydroxylase (thase; official name thymine dioxygenase) and iso-orotate decarboxylase (idcase) have been isolated from fungal sources. thase was isolated from a rhodotorula glutinis cdna library using a degenerate oligonucleotide based on the published amino acid sequence. the coding sequence was transferred to an escherichia coli expression system, from which recombinant thase activity was measured using 14c-labeled thymine. the t ...200515794921
antifungal activity and studies on mode of action of novel xanthoxyline-derived chalcones.chalcones and chalcone-like compounds, most of them new ones, prepared by base-catalyzed condensation of appropriate aldehydes and xanthoxyline, were tested for antifungal properties against a panel of yeasts, hialohyphomycetes as well as dermatophytes with the agar dilution assay. results indicate that neither the sole presence of a "xanthoxyline-like" substitution pattern nor a 2'-oh substituent on ring a are sufficient for these compounds to have antifungal properties. the chalcone 3-(2-chlor ...200515799012
srs2 and recq homologs cooperate in mei-3-mediated homologous recombination repair of neurospora crassa.homologous recombination and post-replication repair facilitate restart of stalled or collapsed replication forks. the srs2 gene of saccharomyces cerevisiae encodes a 3'-5' dna helicase that functions both in homologous recombination repair and in post-replication repair. this study identifies and characterizes the srs2 homolog in neurospora crassa, which we call mus-50. a knockout mutant of n.crassa, mus-50, is sensitive to several dna-damaging agents and genetic analyses indicate that it is ep ...200515800214
a mitogen-activated protein kinase pathway essential for mating and contributing to vegetative growth in neurospora crassa.map kinases homologous to saccharomyces cerevisiae fus3p/kss1p have been identified in plant pathogenic fungi and are required for pathogenicity and sexual reproduction. to better understand the role of map kinase signaling in neurospora crassa, and to identify downstream target genes of the pathway, we isolated, cloned, and disrupted the fus3 homolog mak-2. ste12p is a transcription factor target of fus3p that activates genes of the mating pathway in yeast, and we also characterized the n. cras ...200515802524
biochemical characterization of neurospora crassa glycogenin (gnn), the self-glucosylating initiator of glycogen synthesis.glycogenin acts in the initiation step of glycogen biosynthesis by catalyzing a self-glucosylation reaction. in a previous work [de paula et al., arch. biochem. biophys. 435 (2005) 112-124], we described the isolation of the cdna gnn, which encodes the protein glycogenin (gnn) in neurospora crassa. this work presents a set of biochemical and functional studies confirming the gnn role in glycogen biosynthesis. kinetic experiments showed a very low gnn k(m) (4.41 microm) for the substrate udp-gluc ...200515811343
cytoplasmic contractions in growing fungal hyphae and their morphogenetic consequences.video-enhanced light microscopy of the apical and subapical regions of growing hyphae of several fungal species revealed the existence of momentary synchronized motions of subcellular organelles. first discovered in a temperature-sensitive morphological mutant (ramosa-1) of aspergillus niger, these seemingly spontaneous cytoplasmic contractions were also detected in wild-type hyphae of a. niger, neurospora crassa, and trichoderma atroviride. cytoplasmic contractions in all fungi lasted about 1 s ...200515812630
blue light negatively regulates the sexual filamentation via the cwc1 and cwc2 proteins in cryptococcus neoformans.cryptococcus neoformans is a heterothallic basidiomycetous yeast that primarily infects immunocompromised individuals. dikaryotic hyphae resulting from the fusion of the mata and matalpha mating type strains represent the filamentous stage in the sexual life cycle of c. neoformans. in this study we demonstrate that the production of dikaryotic filaments is inhibited by blue light. to study blue light photoresponse in c. neoformans, we have identified and characterized two genes, cwc1 and cwc2, w ...200515813738
analysis of circadian output rhythms of gene expression in neurospora and mammalian cells in culture.the true biology of chronobiology lies in the spectrum of processes that are controlled by the circadian clock. although this biology plays out at the level of the whole organism, it derives, finally, from clock-driven changes in physiology, and frequently in gene expression, that occur at the level of individual cells. for this reason, analysis of gene expression rhythms measured in cell culture or in organisms that elaborate only a few cell types provides insights not possible in multicellular ...200515817297
discovery of a novel superfamily of type iii polyketide synthases in aspergillus oryzae.identification of genes encoding type iii polyketide synthase (pks) superfamily members in the industrially useful filamentous fungus, aspergillus oryzae, revealed that their distribution is not specific to plants or bacteria. among other aspergilli (aspergillus nidulans and aspergillus fumigatus), a. oryzae was unique in possessing four chalcone synthase (chs)-like genes (csya, csyb, csyc, and csyd). expression of csya, csyb, and csyd genes was confirmed by rt-pcr. comparative genome analyses r ...200515845386
visualizing nuclear migration during conidiophore development in aspergillus nidulans and aspergillus oryzae: multinucleation of conidia occurs through direct migration of plural nuclei from phialides and confers greater viability and early germination in aspergillus oryzae.nuclear migration is indispensable for normal growth, differentiation, and development, and has been studied in several fungi including aspergillus nidulans and neurospora crassa. to better characterize nuclear movement and its consequences during conidiophore development, conidiation, and conidial germination, we performed confocal microscopy and time-lapse imaging on a. nidulans and aspergillus oryzae strains expressing the histone h2b-egfp fusion protein. active trafficking of nuclei from a v ...200515849413
proteomic response of the biological control fungus trichoderma atroviride to growth on the cell walls of rhizoctonia solani.trichoderma atroviride has a natural ability to parasitise phytopathogenic fungi such as rhizoctonia solani and botrytis cinerea, therefore providing an environmentally sound alternative to chemical fungicides in the management of these pathogens. two-dimensional electrophoresis was used to display cellular protein patterns of t. atroviride (t. harzianum p1) grown on media containing either glucose or r. solani cell walls. protein profiles were compared to identify t. atroviride proteins up-regu ...200515856359
composition of complex i from neurospora crassa and disruption of two "accessory" subunits.respiratory chain complex i of the fungus neurospora crassa contains at least 39 polypeptide subunits, of which 35 are conserved in mammals. the 11.5 kda and 14 kda proteins, homologues of bovine ip15 and b16.6, respectively, are conserved among eukaryotes and belong to the membrane domain of the fungal enzyme. the corresponding genes were separately inactivated by repeat-induced point-mutations, and null-mutant strains of the fungus were isolated. the lack of either subunit leads to the accumul ...200415863099
live-cell imaging of tubulin in the filamentous fungus magnaporthe grisea treated with anti-microtubule and anti-microfilament agents.microtubule dynamics were examined in live cells of the fungal plant pathogen magnaporthe grisea transformed for constitutive expression of a fusion protein containing enhanced yellow-fluorescent protein and a neurospora crassa benomyl-resistant allele of beta-tubulin. transformants retained their ability to differentiate appressoria and cause disease but remained sensitive to benomyl. linear microtubule arrays and low-level cytoplasmic fluorescence were observed in vegetative hyphae, conidia, g ...200515868210
cell biology of conidial anastomosis tubes in neurospora crassa.although hyphal fusion has been well documented in mature colonies of filamentous fungi, it has been little studied during colony establishment. here we show that specialized hyphae, called conidial anastomosis tubes (cats), are produced by all types of conidia and by conidial germ tubes of neurospora crassa. the cat is shown to be a cellular element that is morphologically and physiologically distinct from a germ tube and under separate genetic control. in contrast to germ tubes, cats are thinn ...200515879525
the so locus is required for vegetative cell fusion and postfertilization events in neurospora crassa.the process of cell fusion is a basic developmental feature found in most eukaryotic organisms. in filamentous fungi, cell fusion events play an important role during both vegetative growth and sexual reproduction. we employ the model organism neurospora crassa to dissect the mechanisms of cell fusion and cell-cell communication involved in fusion processes. in this study, we characterized a mutant with a mutation in the gene so, which exhibits defects in cell fusion. the so mutant has a pleiotr ...200515879526
three-dimensional image analysis of plugging at the septal pore by woronin body during hypotonic shock inducing hyphal tip bursting in the filamentous fungus aspergillus oryzae.we observed that the filamentous fungus, aspergillus oryzae, grown on agar media burst out cytoplasmic constituents from the hyphal tip soon after flooding with water. woronin body is a specialized organelle known to plug the septal pore adjacent to the lysed compartment to prevent extensive loss of cytoplasm. a. oryzae aohex1 gene homologous to neurospora crassa hex1 gene encoding a major protein in woronin body was expressed as a fusion with dsred2, resulting in visualization of woronin body. ...200515882988
elucidation of the stator organization in the v-atpase of neurospora crassa.v-atpases are membrane protein complexes that pump protons in the lumen of various subcellular compartments at the expense of atp. proton pumping is done by a rotary mechanism that requires a static connection between the membrane pumping domain (v(0)) and the extrinsic catalytic head (v(1)). this static connection is composed of several known subunits of the v-atpase, but their location and topological relationships are still a matter of controversy. here, we propose a model for the v-atpase of ...200515890365
identification of immunogenic proteins from paracoccidioides brasiliensis antigenic fractions f0, fii and fiii.paracoccidioides brasiliensis causes a chronic granulomatous mycosis prevalent in south america, and cell-mediated immunity is the principal mode of protection against this fungal infection. in this context, one of the strategies to discover proteins that are target of an effective immune response against p. brasiliensis is the partial sequencing of cdna from an expression library previously screened with immunoglobulins (ig) to generate antigen sequence tags (ast). in the present work, a p. bra ...200515904973
avidin plate assay system for enzymatic characterization of a histone lysine methyltransferase.modification of proteins by protein methyltransferases has several important biological functions. here, we study the methylation of histone h3 tail at position lys9 by the dim-5 histone lysine methyltransferase, which is involved in epigenetic signaling and gene silencing and which triggers dna methylation in neurospora crassa. we have developed a new assay to detect protein methylation using a biotinylated synthetic peptide substrate and a radioactively labeled coenzyme. we show that the assay ...200515935324
convergent evolution of hydroxylation mechanisms in the fungal kingdom: molybdenum cofactor-independent hydroxylation of xanthine via alpha-ketoglutarate-dependent dioxygenases.the xanthine oxidases and dehydrogenases are among the most conserved enzymes in all living kingdoms. they contain the molybdopterin cofactor moco. we show here that in the fungi, in addition to xanthine dehydrogenase, a completely different enzyme is able to catalyse the oxidation of xanthine to uric acid. in aspergillus nidulans this enzyme is coded by the xana gene. we have cloned the xana gene and determined its sequence. a deletion of the gene has the same phenotype as the previously known ...200515948966
neurospora strains harboring mitochondrial disease-associated mutations in iron-sulfur subunits of complex i.we subjected the genes encoding the 19.3-, 21.3c-, and 51-kda iron-sulfur subunits of respiratory chain complex i from neurospora crassa to site-directed mutagenesis to mimic mutations in human complex i subunits associated with mitochondrial diseases. the v135m substitution was introduced into the 19.3-kda cdna, the p88l and r111h substitutions were separately introduced into the 21.3c-kda cdna, and the a353v and t435m alterations were separately introduced into the 51-kda cdna. the altered cdn ...200515956670
functions of the small proteins in the tom complex of neurospora crasssa.the tom (translocase of the outer mitochondrial membrane) complex of the outer mitochondrial membrane is required for the import of proteins into the organelle. the core tom complex contains five proteins, including three small components tom7, tom6, and tom5. we have created single and double mutants of all combinations of the three small tom proteins of neurospora crassa. analysis of the mutants revealed that tom6 plays a major role in tom complex stability, whereas tom7 has a lesser role. mut ...200515987740
antifungal coating by biofunctionalized polyelectrolyte multilayered films.the surface of medical devices is a common site of bacterial and fungal adhesion, first step to the constitution of a resistant biofilm leading frequently to chronic infections. in order to prevent such complications, several physical and chemical modifications of the device surface have been proposed. here, we experiment a new type of topical antifungal coating using the layer-by-layer technique. the nanometric multilayer film obtained by this technique is functionalized by the insertion of a c ...200515992921
methylation of histone h3 lysine 36 is required for normal development in neurospora crassa.the set domain is an evolutionarily conserved domain found predominantly in histone methyltransferases (hmts). the neurospora crassa genome includes nine set domain genes (set-1 through set-9) in addition to dim-5, which encodes a histone h3 lysine 9 hmt required for dna methylation. we demonstrate that neurospora set-2 encodes a histone h3 lysine 36 (k36) methyltransferase and that it is essential for normal growth and development. we used repeat induced point mutation to make a set-2 mutant (s ...200516087750
the e-hook of tubulin interacts with kinesin's head to increase processivity and speed.kinesins are dimeric motor proteins that move processively along microtubules. it has been proposed that the processivity of conventional kinesins is increased by electrostatic interactions between the positively charged neck of the motor and the negatively charged c-terminus of tubulin (e-hook). in this report we challenge this anchoring hypothesis by studying the motility of a fast fungal kinesin from neurospora crassa (nckin). nckin is highly processive despite lacking the positive charges in ...200516100283
comparative genomics and disorder prediction identify biologically relevant sh3 protein interactions.protein interaction networks are an important part of the post-genomic effort to integrate a part-list view of the cell into system-level understanding. using a set of 11 yeast genomes we show that combining comparative genomics and secondary structure information greatly increases consensus-based prediction of sh3 targets. benchmarking of our method against positive and negative standards gave 83% accuracy with 26% coverage. the concept of an optimal divergence time for effective comparative ge ...200516110343
paracoccidioides brasiliensis translation and protein fate machineries revealed by functional genome analysis.the translational and post-translational modification machineries of paracoccidioides brasiliensis were assessed by means of comparative analyses of pbaests (p. brasiliensis assembled expressed sequence tags) with sequences deposited on different databases. of the 79 sequences corresponding to cytosolic ribosomal proteins, we were able to find 78 in the p. brasiliensis transcriptome. nineteen of the 27 saccharomyces cerevisiae genes related to translation initiation were also found. all eukaryot ...200516110446
the ergosterol biosynthesis pathway, transporter genes, and azole resistance in aspergillus fumigatus.the continuous use of triazoles can result in the development of drug resistance. azole-resistant clinical isolates, spontaneous and induced mutants of aspergillus fumigatus have been documented. the azoles block the ergosterol biosynthesis pathway by inhibiting the enzyme 14-alpha-demethylase, product of the cyp51. fungal azole resistance involves both amino acid changes in the target site that alter drug-target interactions and those that decrease net azole accumulation. the reduced intracellu ...200516110826
deciphering the model pathogenic fungus cryptococcus neoformans.cryptococcus neoformans is a basidiomycete fungal pathogen of humans that has diverged considerably from other model fungi such as neurospora crassa, aspergillus nidulans, saccharomyces cerevisiae and the common human fungal pathogen candida albicans. the recent completion of the genome sequences of two related c. neoformans strains and the ongoing genome sequencing of three other divergent cryptococcus strains with different virulence phenotypes and environmental distributions should improve ou ...200516132036
circadian rhythms in neurospora crassa: clock gene homologues in fungi.computer-based analysis of a total of 17 filamentous fungal and yeasts genomes has shown: (1) homologues of frq, wc-1, wc-2, and vvd, key gene components of the neurospora crassa clock, are present in magnaporthe grisea, gibberella zeae, and podospora anserina, suggesting an frq-based oscillator in these organisms; (2) some fungal species that are more distantly related to neurospora, such as rhizopus oryzae do not appear to have frq homologues; (3) many fungal species that do not appear to cont ...200516154782
[riboswitches].riboswitches are rna structures able to bind small molecules and regulate gene expression at both, transcriptional and translational level. they are present in a wide variety of bacterial species. in bacillus subtilis more than 2% of the genome is regulated by riboswitches. metabolite binding is highly specific and can be provided in cooperative manner. several riboswitches has been identified and characterized to be specific for flavin mononucleotide, thiamine, thiamine pyrophosphate, adenosylc ...200516209348
preprotein translocase of the outer mitochondrial membrane: reconstituted tom40 forms a characteristic tom pore.tom40 is the central pore-forming component of the translocase of the outer mitochondrial membrane (tom complex). different views exist about the secondary structure and electrophysiological characteristics of tom40 from saccharomyces cerevisiae and neurospora crassa. we have directly compared expressed and renatured tom40 from both species and find a high content of beta-structure in circular dichroism measurements in agreement with refined secondary structure predictions. the electrophysiologi ...200516213519
human mitochondrial complex i assembly is mediated by ndufaf1.complex i (nadh:ubiquinone oxidoreductase) is the largest multiprotein enzyme of the oxidative phosphorylation system. its assembly in human cells is poorly understood and no proteins assisting this process have yet been described. a good candidate is ndufaf1, the human homologue of neurospora crassa complex i chaperone cia30. here, we demonstrate that ndufaf1 is a mitochondrial protein that is involved in the complex i assembly process. modulating the intramitochondrial amount of ndufaf1 by kno ...200516218961
growth defect and mutator phenotypes of recq-deficient neurospora crassa mutants separately result from homologous recombination and nonhomologous end joining during repair of dna double-strand breaks.recq helicases function in the maintenance of genome stability in many organisms. the filamentous fungus neurospora crassa has two recq homologs, qde3 and recq2. we found that the qde-3 recq2 double mutant showed a severe growth defect. the growth defect was alleviated by mutation in mei-3, the homolog of yeast rad51, which is required for homologous recombination (hr), suggesting that hr is responsible for this phenotype. we also found that the qde-3 recq2 double mutant showed a mutator phenoty ...200616219790
endocytosis in the plant-pathogenic fungus ustilago maydis.filamentous fungi are an important group of tip-growing organisms, which include numerous plant pathogens such as magnaporthe grisea and ustilago maydis. despite their ecological and economical relevance, we are just beginning to unravel the importance of endocytosis in filamentous fungi. most evidence for endocytosis in filamentous fungi is based on the use of endocytic tracer dyes that are taken up into the cell and delivered to the vacuole. moreover, genomewide screening for candidate genes i ...200516231103
cloning and sequencing of the chromosomal dna and cdna encoding the mitochondrial citrate synthase of aspergillus niger wu-2223l.the complementary dna (cdna) and chromosomal dna encoding the citrate synthase (ec 4.1.3.7) gene (cit1) of aspergillus niger wu-2223l, a citric acid-producing strain, were cloned. synthetic oligonucleotide primers were designed according to the amino acid sequences of already known eukaryotic citrate synthases and the codon bias of a. niger genes. the 920-bp dna fragment was amplified by polymerase chain reaction with these primers using chromosomal dna of wu-2223l as a template, and was employe ...199916232605
group iii histidine kinase is a positive regulator of hog1-type mitogen-activated protein kinase in filamentous fungi.we previously reported that the group iii histidine kinase dic1p in the maize pathogen cochliobolus heterostrophus is involved in resistance to dicarboximide and phenylpyrrole fungicides and in osmotic adaptation. in addition, exposure to the phenylpyrrole fungicide fludioxonil led to improper activation of hog1-type mitogen-activated protein kinases (mapks) in some phytopathogenic fungi, including c. heterostrophus. here we report, for the first time, the relationship between the group iii hist ...200516278449
long-oligomer microarray profiling in neurospora crassa reveals the transcriptional program underlying biochemical and physiological events of conidial germination.to test the inferences of spotted microarray technology against a biochemically well-studied process, we performed transcriptional profiling of conidial germination in the filamentous fungus, neurospora crassa. we first constructed a 70 base oligomer microarray that assays 3366 predicted genes. to estimate the relative gene expression levels and changes in gene expression during conidial germination, we analyzed a circuit design of competitive hybridizations throughout a time course using a baye ...200516287898
genetic and molecular analysis of phytochromes from the filamentous fungus neurospora crassa.phytochromes (phys) comprise a superfamily of red-/far-red-light-sensing proteins. whereas higher-plant phys that control numerous growth and developmental processes have been well described, the biochemical characteristics and functions of the microbial forms are largely unknown. here, we describe analyses of the expression, regulation, and activities of two phys in the filamentous fungus neurospora crassa. in addition to containing the signature n-terminal domain predicted to covalently associ ...200516339731
extraction and quantification of solutes in solidified agar culture media.a method is described for determining the concentration of certain solutes in solidified culture media. the method is based upon the finding that under specified conditions the concentration of solute in an agar gel (c(g)) is related to the concentration of solute in a centrifugally extracted gel supernatant (c(s)) by the ratio, c(g)/c(s), which is characteristic for each solute. the method avoids direct assays of the gels and instead involves assaying the supernatants from inoculated and uninoc ...197916345342
genetic transformation of the biocontrol fungus gliocladium virens to benomyl resistance.methodology was developed to isolate and regenerate protoplasts from the biocontrol fungus gliocladium virens and to transform them to benomyl resistance with a neurospora crassa beta-tubulin gene. southern blots demonstrated that multiple copies of the vector integrated into the chromosomal dna of stable biotypes but not of abortive transformants. analysis of nuclear condition in vegetative and asexual structures demonstrated that no structure of g. virens is dependably uninucleate and thus pre ...199016348312
occurrence of nitrate reductase and molybdopterin in xanthomonas maltophilia.fifteen of 23 atcc strains and 2 of 9 clinical isolates of xanthomonas maltophilia, all of which grew aerobically on ammonia, but not nitrate, as a sole nitrogen source, reduced nitrate to nitrite. x. maltophilia failed to grow anaerobically on complex medium with or without nitrate, so it is considered an obligate aerobe. nitrate-reducing strains contained reduced methyl viologen nitrate reductase (mvh-nr) with specific activities ranging from 49.2 to 192 u mg of protein. strain atcc 17666 doub ...199016348378
purification of two nitrate reductases from xanthomonas maltophilia grown in aerobic cultures.xanthomonas maltophilia atcc 17666 is an obligate aerobe that accumulates nitrite when grown on nitrate. spectra of membranes from nitrate-grown cells exhibited b-type cytochrome peaks and a(615-630) indicative of d-type cytochrome but no absorption peaks corresponding to c-type cytochromes. the nitrate reductase (nr) activity was located in the membrane fraction. triton x-100-extracted reduced methyl viologen-nrs were purified on de-52, hydroxylapatite, and sephacryl s-300 columns to specific a ...199216348805
isolation and characterization of a sodium-dependent phosphate transporter gene in dunaliella viridis.a sodium-dependent phosphate transporter gene, dvspt1, was isolated from a cdna library using a probe derived from a subtracted cdna library of dunaliella viridis. sequencing analyses revealed a cdna sequence of 2649 bp long and encoded an open-reading frame consisting of 672 amino acids. the deduced amino acid sequence of dvspt1 exhibited 31.2% identity to that of tcpho from tetraselmis chui. hydrophobicity and secondary structure prediction revealed 11 conserved transmembrane domains similar t ...200616359638
molecular cloning, expression, and characterization of the cu,zn superoxide dismutase (sod1) gene from the entomopathogenic fungus cordyceps militaris.we describe the molecular characterization of the cu,zn superoxide dismutase (sod1) gene of cordyceps militaris, which is one of the entomopathogenic fungi called a vegetable wasp and plant worm. the sod1 gene of c. militaris spans 922 bp and consisted of three introns and four exons coding for 154 amino acid residues. the deduced amino acid sequence of the c. militaris sod1 cdna showed 88% identity to claviceps purpurea sod1, 82% to neurospora crassa sod1, and 75-64% to sod1 sequences from othe ...200516389964
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