Ribonucleotides
Mostrando 1-12 de 179 artigos, teses e dissertações.
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1. Aproveitamento biotecnológico do glicerol derivado da produção de biodiesel para a obtenção de biomassa e ribonucleotídeos / Biotechnological utilization of glycerol derived from biodiesel production for obtaining biomass and ribonucleotides
Este trabalho teve como objetivo a utilização de glicerol, principal subproduto da produção de biodiesel, como fonte de carbono para a produção de biomassa e ribonucleotídeos de leveduras. Com este propósito, foi realizado um screening de leveduras para identificar aquelas cepas com maior capacidade de crescimento em glicerol. As leveduras Hansenula
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/09/2008
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2. COMPLEXOS METÁLICOS DE 2-PIRIDINOFORMAMIDA TIOSSEMICARBAZONAS: ESTUDOS EM SOLUÇÃO, NO ESTADO SÓLIDO E ATIVIDADE CITOTÓXICA / METAL COMPLEXES OF 2-PYRIDINEFORMAMIDE THIOSEMICARBAZONES: SOLUTION STUDIES, SOLID STATE STUDIES AND CYTOTOXIC ACTIVITY.
Thiosemicarbazones and their metal complexes present a wide range of bioactivities. It has been shown that the antitumoral action of á(N)-heterocyclic thiosemicarbazones occurs through the inhibition of ribonucleotide diphosphate reductase (RDR), a key enzyme involved in the conversion of ribonucleotides into deoxyribonucleotides during DNA syntheses. The a
Publicado em: 2008
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3. Produção de biomassa a partir do soro de queijo para obtenção de ribonucleotideos. / Production of biomass by whey to ribonucleotides obtention.
O soro de queijo é um subproduto da indústria de laticínios que pode ser aproveitado como subproduto em processos fermentativos, na produção de biomassa principalmente de leveduras. Após autólise, quando a parede celular da levedura é rompida e a molécula de RNA parcialmente hidrolisada através da ação de enzimas intracelulares, alguns ribonucleo
Publicado em: 2006
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4. Position-specific effect of ribonucleotides on the cleavage activity of human topoisomerase II
Beyond the normal DNA transactions mediated by topoisomerase II, we have recently demonstrated that the cleavage activity of the two human topoisomerase II isoforms is several-fold stimulated if a ribonucleotide rather than a deoxyribonucleotide is present at the scissile phosphodiester in one strand of the substrate. Here we show that ribonucleotides exert
Oxford University Press.
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5. Polymerase Mu Is a DNA-Directed DNA/RNA Polymerase
DNA polymerases are defined as such because they use deoxynucleotides instead of ribonucleotides with high specificity. We show here that polymerase mu (pol μ), implicated in the nonhomologous end-joining pathway for repair of DNA double-strand breaks, incorporates both ribonucleotides and deoxynucleotides in a template-directed manner. pol μ has an approx
American Society for Microbiology.
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6. The Presence of Ribonucleotides in Mature Closed-Circular Mitochondrial DNA
Mitochondrial DNA from mouse and HeLa cells is nicked by alkali and chick-embryo ribonuclease H. It has been concluded that ribonucleotides are present in the closed-circular duplex. A comparative study of the scission rates at pH 13.0 of RNA and of mitochondrial DNAs indicates that there are no more than 10 ribonucleotides in the major fraction of the mitoc
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7. Nuclease resistant ribozymes with high catalytic activity.
Hammerhead ribozymes are efficient RNA enzymes characterized by a typical hammerhead secondary structure and a number of conserved bases. Little is known about the role of the ribose-phosphate backbone, although it is obviously important since a DNA molecule with the same base sequence is not a catalyst. Here we describe the synthesis of artificial ribozymes
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8. Ribonucleotides Covalently Linked to Deoxyribonucleic Acid in T4 Bacteriophage
Bacteriophage T4 was grown in the presence of labeled uridine. The deoxyribonucleic acid (DNA) of the phage was shown to contain covalently attached ribonucleotides. The label appears not to be internal in the DNA strands. Presumably, it is at the ends of the DNA strands and this may be related to DNA initiation.
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9. Regulation of IMP dehydrogenase gene expression by its end products, guanine nucleotides.
To study the regulation of IMP dehydrogenase (IMPDH), the rate-limiting enzyme of guanine nucleotide biosynthesis, we examined the effects of nucleosides, nucleotides, nucleotide analogs, or the IMPDH inhibitor mycophenolic acid (MPA) on the steady-state levels of IMPDH mRNA. The results indicated that IMPDH gene expression is regulated inversely by the intr
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10. A small DNA molecule containing covalently-linked ribonucleotides originates from the large intergenic region of the cauliflower mosaic virus genome.
We have detected a small DNA molecule (sa-DNA), 725 nucleotides long, in cauliflower mosaic virus (CaMV)-infected, but not non-infected, turnip leaves. Alkali and RNase A treatments shortened sa-DNA by 100 nucleotides and we conclude that it contains covalently-linked ribonucleotides. This DNA co-purified with cellular polyadenylated RNA. It is complementary
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11. Preparation of isotopically labeled ribonucleotides for multidimensional NMR spectroscopy of RNA.
A general method for large scale preparation of uniformly isotopically labeled ribonucleotides and RNAs is described. Bacteria are grown on isotopic growth medium, and their nucleic acids are harvested and degraded to mononucleotides. These are enzymatically converted into ribonucleoside triphosphates, which are used in transcription reactions in vitro to pr
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12. A single side chain prevents Escherichia coli DNA polymerase I (Klenow fragment) from incorporating ribonucleotides
Although nucleic acid polymerases from different families show striking similarities in structure, they maintain stringent specificity for the sugar structure of the incoming nucleoside triphosphate. The Klenow fragment of E. coli DNA polymerase I selects its natural substrates, deoxynucleotides, over ribonucleotides by several thousand fold. Analysis of mut
The National Academy of Sciences.