NUCLEAR EXTRACT OF XENOPUS-LAEVIS OOCYTES THAT ACCURATELY TRANSCRIBES 5S-RNA GENES
NUCLEAR EXTRACT OF XENOPUS-LAEVIS OOCYTES THAT ACCURATELY TRANSCRIBES 5S-RNA GENES
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DOI：
10.1016/0092-8674(78)90291-x
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发表时间：
1978-01-01
期刊：
影响因子：
64.5
通讯作者：
JORDAN, E
中科院分区：
文献类型：
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作者：
BIRKENMEIER, EH;BROWN, DD;JORDAN, E
当将与质粒pMB 9重组的非洲爪蟾5S RNA基因加入到从非洲爪蟾破碎的细胞核获得的上清液部分中时，可以准确地转录。卵母细胞在最初的30分钟滞后期后，5S RNA的合成速率在至少1小时内是恒定的，并且在18小时后仍然检测到合成。从这些实验中使用的重组DNA合成的总RNA的多达40%可以是5S RNA。5S RNA基因的编码链的转录速率比非编码链高10-15倍。质粒和间隔区DNA也被转录。在5S RNA中合成的总RNA的分数受到DNA浓度、离子强度和MgCl 2浓度的强烈影响。通过中等浓度的α-β-CD抑制转录鹅膏蕈碱证明RNA聚合酶III转录所有合成RNA的至少90%。腺病毒2 DNA通过RNA聚合酶III在核上清液中转录。合成的总RNA中约有15%在丙烯酰胺凝胶中迁移为5.5S RNA条带，并通过其寡核苷酸指纹鉴定为病毒相关RNA 1。
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 X. laevis oocytes. After an initial 30 min lag period, the rate of synthesis of 5S RNA is constant for at least 1 h and synthesis is still detected after 18 h. 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 10-15 times greater than the noncoding strand. Plasmid and spacer DNA are also transcribed. That fraction of total RNA synthesized in 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 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 was identified as virus-associated RNA1 by its oligonucleotide fingerprint.