共查询到20条相似文献,搜索用时 15 毫秒
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G Goldberg T Zarucki-Schulz P Caldwell H Weissbach N Brot 《Biochemical and biophysical research communications》1979,91(4):1453-1461
The DNA dependent synthesis of ribosomal protein L12 and the β subunit of RNA polymerase has been investigated using DNA from a plasmid which contains the genetic information for ribosomal protein L12 and the β subunit of RNA polymerase. This DNA, however, lacks the promoter region and the genetic information for the first 26 amino acids of ribosomal protein L10. It was found that L12 and the β subunit of RNA polymerase are efficiently synthesized from this DNA. These results suggest that L12 and the β subunit of RNA polymerase can be synthesized from a promoter situated within the L10 gene. 相似文献
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James L. White 《Biochemical and biophysical research communications》1978,83(3):1099-1104
3′-deoxyadenosine triphosphate inhibited [3H]UMP incorporation by RNA-dependent RNA polymerases from tobacco and cowpea plants. The inhibition of [3H]UMP incorporation could be reversed by simultaneous addition of higher ATP concentrations but not with increasing concentrations of UTP or when excess ATP was added 10 min after the inhibitor. These results suggest 3′-deoxyadenosine triphosphate competes specifically with ATP in reaction mixtures and results in premature termination of RNA synthesis by RNA-dependent RNA polymerase. 相似文献
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Farzin Farzaneh Colin K. Pearson 《Biochemical and biophysical research communications》1978,84(3):537-543
We have studied the synthesis of poly(ADP-ribose) by nuclei isolated from embryos at different stages of development. Determination of the total chain length of poly(ADP-ribose) molecules by hydroxylapatite column chromatography generally gave higher values than when the radioactive portions of these molecules, synthesized , were measured by poly(ethyleneimine)-cellulose thin layer chromatography, after snake venom phosphodiesterase digestion. The results show that most of the poly(ADP-ribose) synthesized is a covalent elongation of molecules previously initiated . 相似文献
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F L Yu 《Biochemical and biophysical research communications》1975,64(3):1107-1115
Rat liver nuclei, seventeen hours after partial hepatectomy, showed a two to three-fold increase in total RNA synthesis over the sham operated controls. When tested with exogenous synthetic template, this was found to be mainly a reflection of increased levels of both the nuclear free and engaged RNA polymerase activities . It was also observed that there was a greater stimulation of the species of RNA polymerase that are α-amanitin resistant than sensitive (3.2 μg/ml). This observation was further confirmed by DEAE-Sephadex column chromatography of the solubilized nuclear free and engaged RNA polymerases and found RNA polymerase I and IIIa were the major species greatly stimulated during this period of liver regeneration. These data suggest not only that there exists a sensitive equilibrium between the nuclear free and engaged RNA polymerases; they also suggest the possibility that RNA polymerase itself may play a positive role in the regulation of gene expression. 相似文献
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RNA synthesized by maize RNA polymerase II arises in part from repeated DNA sequences, since significant hybridization to the parent DNA occurs with low concentrations of RNA and DNA. Over three times as much “repeated sequence” RNA is transcribed from maize as from calf thymus DNA. 相似文献
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Leroy M. Nyberg A.-Li Hu Ruey M. Loor Tung Y. Wang 《Biochemical and biophysical research communications》1976,73(2):330-335
The effect of androgens on gene activation in the rat prostate has been investigated by examining precursor incorporation into RNA, by DNA-RNA hybridization of RNA transcribed from prostate chromatin, and by thermal denaturation of prostatic chromatin. The results show a selective synthesis of nuclear RNA and a changed thermal melting profile of prostatic chromatin as a result of testosterone administration. Further, the synthesized RNA transcribed from prostatic chromatin of androgen-treated rats contained new RNA species that were not transcribed from chromatin of untreated castrated controls. The data provide direct evidence for an activated state of the prostatic chromatin stimulated by androgens. 相似文献
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Transcription of chromatin by human RNA polymerase 总被引:3,自引:0,他引:3
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DNA polymerase activities in cell-free lysates of unfertilized eggs, larvae and immature ovaries of were compared to purified DNA polymerase I using several natural and synthetic templates. The templates were tested as the native and denatured forms of normal and DNase I treated molecules. Although the polymerases tended to prefer DNase I treated Xenopus DNA over the other templates tested, so did the polymerase I. In general, the template preferences of the polymerases studied depended in complex ways on both the form and the species of origin of the template. 相似文献
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Altered restriction of nuclear RNA during incubation in vitro 总被引:1,自引:0,他引:1
Nuclei were isolated from rat liver and incubated in two commonly employed RNA transport assays. Released [14C] RNA was isolated and hybridized with filter-bound DNA in the presence of competing cytoplasmic RNA. A significant portion of RNA which was transported to either medium was not represented in cytoplasmic RNA. These results indicate that the restriction of some sequences to the nucleus is not maintained . 相似文献
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Monoamine oxidase, an intrinsic protein of outer mitochondrial membrane, was purified from bovine liver and rabbit antibody against the enzyme was prepared. The antibody could react with the monoamine oxidase of rat liver mitochondria. When rat liver RNA was translated using rabbit reticulocyte lysate and monoamine oxidase peptide in the translation products was immunoprecipitated by the antibody, the peptide was detected in the products programmed by the messenger RNA's from total and free polysomes but not that from bound polysomes. The enzyme synthesized had the same apparent molecular size as the mature protein in outer mitochondrial membrane. 相似文献
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Sulfite oxidase, a soluble enzyme in mitochondrial intermembrane space, was synthesized as a precursor protein larger than the authentic enzyme when rat liver RNA was translated using reticulocyte lysate. When the translation products were incubated with isolated rat liver mitochondria, the precursor of sulfite oxidase was converted to the size of the mature enzyme. The processed mature enzyme was no longer susceptible to externally added proteases and was extractable by a hypotonic treatment of the mitochondria, suggesting its location in the intermembrane space. When mitochondria were subfractionated, most of the processing activity was recovered in the mitoplast fraction. The import-processing activity of mitochondria was inhibited by CCCP, oligomycin, or atractyloside in the presence of KCN. These results suggest that the import of sulfite oxidase into mitochondrial intermembrane space requires the participation of inner membrane. 相似文献