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At least 55 records · Page 3Linked to original sources
PubMed1994

The Claviceps purpurea glyceraldehyde-3-phosphate dehydrogenase gene: cloning, characterization, and use for the improvement of a dominant selection system.

The GPD 1 gene of Claviceps purpurea coding for glyceraldehyde-3-phosphate dehydrogenase was cloned and sequenced, including 1,800 bp of its 5' upstream region. This gene shows an identical structure to the gpd gene of Podospora anserina and Cryphonectria parasitica (one intron at an identical position) with high homology at both the DNA and amino-acid levels. Two fragments of the promoter spanning from the ATG to -500 bp and to -1,400 bp were fused to the phleomycin-resistance gene. Both constructs transformed C. purpurea at a high rate. The enhanced expression of the long vector construct indicates the presence of additional elements between -500 bp and -1,400 bp upstream of the initiation codon.

Amino Acid Sequence↗
PubMed1993

Interaction between mitochondrial DNA and mitochondrial plasmids in Claviceps purpurea: analysis of plasmid-homologous sequences upstream of the lrRNA-gene.

Homology of two linear, mitochondrial (mt) Claviceps purpurea plasmids, pClK1 and pClT5, to the upstream region of the large ribosomal RNA gene in the mtDNA of three strains (W3, T5 and K) has been investigated in detail to explore the widespread phenomenon of homology between mt plasmids and mtDNA in C. purpurea. Sequence comparison indicates that recombination between free plasmids and mtDNA is the cause of the observed homology. The process is similar to the integration of the structurally related adenoviruses into the mammalian genome. As in other fungi, palindromic sequences seem to be involved in this mitochondrial recombination process.

Base Sequence↗
PubMed1989

The linear mitochondrial plasmid pClK1 of the phytopathogenic fungus Claviceps purpurea may code for a DNA polymerase and an RNA polymerase.

Plasmid pClK1, a linear mitochondrial plasmid of Claviceps purpurea, was completely sequenced. The sequence contains two long open reading frames (ORF1, 3291 bp; ORF2, 2910 bp), and at least four smaller ORFs. The potential polypeptide derived from ORF1 shows homology to the family B type DNA polymerases. The product of ORF2 has significant homology to the mitochondrial RNA polymerase of yeast and RNA polymerases from bacteriophages. ORF1 and ORF2 show homology to URF3 and URF1 of the maize plasmids S1 and S2, respectively. No homology to any published protein sequence was found for the smaller ORFs. The origin of the terminal protein attached to the 5' ends of pClK1 remains open; several alternatives for its origin are discussed. The sequence data as a whole confirm the virus-like character of pClK1 already postulated from structural properties. Thus pClK1 together with S plasmids of maize and several other linear plasmids make up a distinct class of DNA species of plants and fungi probably derived from a common virus-like ancestor.

Amino Acid Sequence↗
PubMed1992

Transcripts and translation products of a mitochondrial plasmid of Claviceps purpurea.

Expression of the linear mitochondrial (mt) plasmid pClK1 of strain K of the ascomycete Claviceps purpurea was studied at the RNA and protein level. Using strand-specific probes two major transcripts were detected, corresponding to ORF1 and ORF2 of the plasmid, which most likely code for a DNA-polymerase and an RNA-polymerase, respectively. Primer extension experiments showed that both transcripts start at identical positions from opposite sides within the terminal inverted repeat (TIR). The initiation sequence corresponds to the proposed general mt initiation consensus-sequence. Conserved parts of the putative polymerase ORFs were expressed in an E. coli system and used to prepare antisera. In Western experiments the presence of corresponding proteins was demonstrated in a strain carrying plasmid pClK1, whereas a plasmid-free strain lacked these polypeptides. The sizes of these proteins are in good accordance with the sizes derived from the coding capacity of ORF1 and 2.

Base Sequence↗
PubMed1988

Structural and functional analysis of mitochondrial plasmids in Claviceps purpurea.

Several strains of Claviceps purpurea, a phytopathogenic Ascomycete, contain mitochondrial (mt) plasmids in high molar excess relative to mtDNA. Comparative analysis of plasmids of four strains of different geographic origin revealed that all the plasmids are structurally related (size; linearity; restriction map; probably 5'-linked terminal protein; terminal inverted repeats, TIRs); two of them are even identical, indicating a possible mobility of these genetic entities. In strain K it was shown that plasmid titres are comparably high in axenic cultures and in parasitic structures (sclerotia). Detailed analysis of plasmid pClK1 proved the existence of a perfect TIR of 327 bp; the plasmid's structure and details of its nucleotide sequence indicate a replication modus comparable to that of adenoviruses. pClK1 is almost completely transcribed resulting in two major transcripts of 3.5 and 3.15 kb, respectively. In plasmid-free strains (cured by ethidium bromide treatment) these mRNAs are not detectable; nevertheless they show no significant difference in phenotype. As judged from their structural properties they could be derived from viral ancestors. In this context the plasmids' close relationship to mt plasmids of higher plants may be of special interest.

Adenoviridae↗
PubMed1976

Origin of sclerotia-like cells in submerged Claviceps purpurea producing clavine alkaloids.

Ultrathin sectioning of submerged mycelium of Claviceps purpurea Tul. producing clavine alkaloids revealed yeast-like budding resulting in asexual spores-blastospores. These deciduous spores were born by extended hyphal cells and retained the same ultrastructure of cell organelles. Both the extended hyphae and the blastospores resembled the cells of ergot sclerotial tissue. A surface culture of C. purpurea Tul. producing no alkaloids was used as a reference.

Claviceps↗
PubMed1977

Electron-cytochemical demonstration of acid phosphatase in saprophytic Claviceps purpurea.

p-Nitrophenylphosphate in combination with lead salt technique was used for the cytochemical localization of acid phosphatase (EC 3.1.3.2) in saprophytic submerged culture of Claviceps purpurea Tul. The lead reaction product was found in capsular fibrils, in the newly formed parts of the cell wall and in the vacuoles of aged cells (autolysosomes). Phosphatase activity was present also in particulate intra-cytoplasmatic organelles. The concentric layering of lead deposits in these organelles indicates their relationship to endoplasmic reticulum membranes.

Acid Phosphatase↗
PubMed1978

Fine structural localization of alkaloid synthesis in endoplasmic reticulum of submerged Claviceps purpurea.

Acetyl coenzyme A (CoA) carboxylase (EC 6.4.1.2), an enzyme catalyzing the synthesis of malonyl-CoA, was cytochemically localized in endoplasmic reticulum (ER) of sclerotia-like cells of submerged Claviceps purpurea Tul. producing clavine alkaloids. The enzymic activity was structurally bound in unit membranes of ER strands which, later on, evolved into vacuoles containing lipoprotein material. The reaction product was absent from ER in nonvacuolized filamentous hyphae and ovoid asexual spores containing numerous lipid globules; it was also absent from ER in the mycelium of submerged C. purpurea strain producing no alkaloids. In view of our previous morphogenetic observations and the available biochemical evidence, the observed localization of acetyl-CoA carboxylase was assumed not to coincide with fatty acid biosynthesis but to represent sites of alkaloid synthesis.

Acetyl-CoA Carboxylase↗
PubMed1985

Role of the delta 8 double bond of agroclavine in lysergic acid amide biosynthesis by Claviceps purpurea.

Agroclavine, given to actively-growing sclerotial tissue of a strain of Claviceps purpurea which can not normally elaborate ergot alkaloids, was transformed by this tissue into lysergic acid amide with overall efficiency of approximately 40%. By contrast, festuclavine (8,9-dihydro-agroclavine) was not transformed, indicating specificity in the mechanism of lysergyl biosynthesis.

Claviceps↗
PubMed1982

Quantitative changes of the alkaloid complex in a submerged culture of Claviceps paspali.

Claviceps paspali FA produced high concentrations of alkaloid under submerged conditions. Their production was found to depend on the developmental stage and treatment of the filamentous culture inoculum. A medium containing Bacto-peptone with a constant composition of amino acids was selected for the preparation of the inoculum. A two-week fermentation in a synthetic medium with mannitol at 24 +/- 1 degrees C resulted in an increased production of total alkaloids from the original value of 100-200 micrograms/mL to more than 2000 micrograms/mL. Addition of tryptophan did not further increase the production of alkaloids but resulted in changes of the spectrum of some metabolites, 2,3-Dihydroxybenzoic acid accompanied the alkaloids in the fermentation medium. alpha-Hydroxyethyllysergamide was the predominant component of extracellular alkaloids (80% in the first days of fermentation). During fermentation the level of this alkaloid continuously decreased while the concentration of the accompanying alkaloids, i.e. lysergamide and the corresponding minor isomers, increased.

Alkaloids↗
PubMed1975

Production of alkaloids and differentiation in a submerged culture of Claviceps purpurea (Fr.) Tul.

The submerged culture of the Claviceps purpurea strain studied was polymorphous. In the process of alkaloid synthesis, cytodifferentiation preceded biochemical differentiation. The onset of the alkaloid phase was characterized by: predominance of chlamydospores in the culture, the presence of vegetative cells with reduced or arrested proliferation, maximum acetylCoA carboxylase activity, the maximum amount of total fatty acids, an over-average cell pool tryptophan level and minimum tryptophan synthetase activity. Intracellular ricinoleic acid was an indicator of differentiation of the culture towards alkaloid formation and also of alkaloid synthesis. The cytodifferentiation period in the initial phases of fermentation, when the cell has several alternative possibilities of development, is regarded as the most sensitive sector of the regulatory mechanisms of alkaloid formation.

Acetyl-CoA Carboxylase↗
PubMed1976

A method of preparation and application of nitrous acid as a mutagen in Claviceps purpurea.

A simple and speedy procedure is described for the preparation and application of nitrous acid in mutagenic experiments. The conventional incubation mixture of sodium nitrite solution with acetate buffer is replaced by an aqueous solution of nitrous acid prepared by running a solution of sodium nitrite through a column of ion exchange. The procedure eliminates also the interference of other substances. Experimental appraisal of the technique was done during the mutagenic improval of the fungus Claviceps purpurea.

Claviceps↗
PubMed1982

Activities of catabolic pathways and alkaloid biogenesis during submerged cultivation of Claviceps sp. SD-58.

Alkaloid biogenesis in Claviceps sp. SD-58 was found to be associated with low growth and reduced consumption of sucrose and mannitol. The activities of glucose-6-phosphate dehydrogenase and aldolase increased up to 9 d of the fermentation cycle and then declined. A close parallel between the operation of pentose phosphate and glycolytic pathways and tryptophan content was demonstrated. An inverse relation between the operation of citric acid and glyoxylate cycles and the ability of the cells to synthesize alkaloids was noted. The role of carbon metabolic pathways during fermentative production of alkaloids is discussed.

Citric Acid Cycle↗
PubMed1983

Alkaloid production by Claviceps sp. SD-58; involvement of phosphatase isozymes.

Simultaneous reduction in alkaloid yield and level of phosphatases by high concentrations of phosphate was observed in Claviceps sp. SD-58. Tryptophan-induced culture showed an increase in alkaloid yield and the level of phosphatases. Phosphate caused repression of both acid phosphatase (isoenzyme I) and alkaline phosphatase (isoenzymes III and V).

Acid Phosphatase↗
PubMed2003

Purcopia, a Ty1-copia truncated retroelement in the genome of Claviceps purpurea.

Truncated copy of reverse transcriptase of Ty1/copia retroelement (Purcopia) was found as part of the species-specific RAPD 257(540) marker of Claviceps purpurea. A region of 94 bp with 78.9% identity to an unannotated region of the genomic clone of the rice blast fungus Pyricularia grisea (accession no. AQ162050) was found at the 5' end of the pseudogene. Comparison with database sequences revealed that Purcopia is close to the plant retroelements represented by Tto1, Ta1-3 and Bare-1, whereas the other fungal elements of the Ty1/copia type grouped with Hopscotch elements. Restriction patterns obtained by hybridization of the labeled marker to HindIII digested genomic DNA of various C. purpurea isolates contained multiple bands. The banding was individual and did not yield any species- or population-specific fragments or patterns.

Amino Acid Sequence↗
PubMed2003

Secretion of acid phosphatase in Claviceps purpurea--an ultracytochemical study.

The lead phosphate precipitation method showed the reaction product of acid phosphatase (which reflects the presence of the enzyme glycoprotein) in peripheral cytoplasmic vesicles in the ascomycetous fungus Claviceps purpurea. The product appeared to diffuse from these vesicles (diameter 100-200 nm) towards the cell wall, usually to its sites covered by the capsular fibres exhibiting also acid phosphatase activity. This observation of diffusion of secretory glycoprotein in the cytoplasmic matrix and its orientation to the plasmalemma and capsular fibrils suggests an alternative to the well-described secretory mechanism of transport and exocytosis of glycoproteins via membrane-bound transport conveyors fusing with the cell membrane. It confirms and enlarges our previous finding of the reaction product of acid phosphatase performed by ultrastructural cytochemistry in vacuoles (lysosomes), in the growing cell septum, in cytoplasmic vesicles and in the fibres of the external capsule.

Acid Phosphatase↗
PubMed2004

Physiological dendrogram of Claviceps spp. based on sucrose metabolism in submerged cultures and its comparison with phylogenetic tree.

Sixteen isolates of Claviceps spp. were analyzed for the production of polysaccharides, oligosaccharides, and sucrose metabolism under conditions of submerged fermentation. Physiological markers calculated by the Verhulst-Pearl law were used for hierarchical cluster analysis. Low correlation was found between physiologically based dendrogram and phylogenetic analysis constructed from an alignment of rDNA sequences. To confirm the intraspecific uniformity of physiological markers three isolates of C. africana from different hosts and locations were included. The influence of genotype, physiological variability, environmental location and habitat on metabolite production is discussed.

Claviceps↗