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Query: UMLS:C0001486 (Adenovirus)
 3,125 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Xenopus 5S RNA genes in recombinant form with the plasmid pMB9 are transcribed accurately when added to a supernatant fraction obtained from disrupted nuclei of Xenopus laevis oocytes. After an initial 30 min lag period, the rate of synthesis of 5S RNA is constant for at least an hour and synthesis is still detected after 18 hr. As much as 40% of the total RNA synthesized from the recombinant DNA used in these experiments can be 5S RNA. The coding strand of the 5S RNA genes is transcribed at a rate 10 to 15 times greater than the noncoding strand. Plasmid and spacer DNA, however, are also transcribed. What fraction of total RNA synthesized is 5S RNA is strongly affected by DNA concentration, ionic strength and MgCl2 concentration. Inhibition of transcription by intermediate concentrations of alpha-amanitin demonstrates that RNA polymerase III transcribes at least 90% of all RNA synthesized. Adenovirus 2 DNA is also transcribed in the nuclear supernatant by RNA polymerase III. Approximately 15% of the total RNA synthesized migrates in an acrylamide gel as a band of 5.5S RNA and has been identified as virus-associated RNA1 by its oligonucleotide fingerprint.
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PMID:A nuclear extract of Xenopus laevis oocytes that accurately transcribes 5S RNA genes. 56 51

An in vitro transcription system has been developed from 0.3M NaCl extracts of nuclei of Drosophila embryos. Optimal transcription in the Drosophila embryo extract (DEX) was at 5mM MgCl2, 70mM KCl, 25 degrees C and with promoter concentrations of 0,75-1.0 pmol/assay. In vitro transcription from the Adenovirus-2 major late and the Drosophila histone gene promoters was studied in particular. S1-nuclease protection experiments showed that in vitro transcription from these promoters was accurate. In vitro transcription from the Adenovirus-2 major late promoter was less efficient than from histone gene H3 and H4 promoters in DEX. Vicecersa, in vitro transcription from Adenovirus-2 major late promoter was more efficient in HeLa whole cell extracts. The efficiencies of transcription from histone gene promoters decreased in DEX in the order H4 greater than or equal to H3 greater than H2a. Transcription from H2b and H1 promoters was not detected in DEX. The transcription from the Adenovirus-2 major late promoter was completely inhibited by histone H3 and H4 promoters. Preincubation of DEX with the adenoviral template, however, did not inhibit transcription from histone H3 and H4 promoters. The transcription start sites of histone genes H3 and H4 are separated by 160 base pairs. The H3 and H4 transcription start sites were subcloned separately. Now, a competition of transcription from the H3/H4 promoters with the Adenovirus-2 major late promoter was observed. The competition studies suggest that preincubation of DEX with the adenoviral template inhibited transcription from the H3 promoter more strongly than from the H4 promoter.
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PMID:In vitro transcription with extracts of nuclei of Drosophila embryos. 298 64

Adenovirus DNA binding protein is a multifunctional protein essential for viral DNA replication. To investigate the role of the DNA binding protein in this process its interaction with partial DNA duplexes was examined. Duplex regions of DNA, created when a short DNA strand is annealed to its complementary sequence present in the single stranded form of M13 phage DNA, were efficiently unwound by DNA binding protein in a reaction that required neither ATP nor MgCl2. The unwinding activity of DNA binding protein was reduced by conditions which increased the stability of DNA duplexes. DNA unwinding by DNA binding protein was highly co-operative and required the single stranded DNA to be completely coated with the protein. Completely double stranded DNA could also be unwound by DNA binding protein but this reaction was sensitive to the G+C content of the DNA and could only be observed with relatively short DNA duplexes up to 45 base pairs in length. When these short double stranded DNA molecules contained binding sites for the transcription factors NFI and NFIII addition of the cognate factor blocked DNA binding protein mediated unwinding of the particular DNA duplex. Cleavage of DNA binding protein with chymotrypsin and isolation of the 39,000 molecular weight C-terminal fragment indicated that the unwinding activity was located in this domain of the protein. In support of this contention a monoclonal antibody, which had previously been mapped to this region, specifically inhibited the DNA unwinding activity. These activities of DNA binding protein are likely to be involved in DNA replication, where the destabilisation of DNA duplexes could be important both during initiation and elongation.
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PMID:Adenovirus DNA binding protein: helix destabilising properties. 813 13