DNA TOPOLOGY AND A MINIMAL SET OF BASAL FACTORS FOR TRANSCRIPTION BY RNA POLYMERASE-II
DNA TOPOLOGY AND A MINIMAL SET OF BASAL FACTORS FOR TRANSCRIPTION BY RNA POLYMERASE-II
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DOI：
10.1016/0092-8674(93)90140-l
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发表时间：
1993-05-07
期刊：
影响因子：
64.5
通讯作者：
SHARP, PA
中科院分区：
文献类型：
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作者：
PARVIN, JD;SHARP, PA
当模板为负超螺旋时，免疫球蛋白重链（IgH）基因体外转录可以用仅含有TATA结合蛋白（TBP）、TFIIB和RNA聚合酶II（pol II）的最小反应重建。从含有IgH或腺病毒主要晚期启动子（MLP）的线性DNA模板转录还需要TFIIF、TFIIE、TFIIH和含有TFIIA和TFIIJ的级分。启动子在最小反应中的活性不同。在该反应中没有观察到在腺病毒MLP位点的起始，即使用含有负超螺旋密度的模板。当只有TBP、TFIIB和pol II存在于反应中时，IgH模板DNA的负超螺旋越多，转录越活跃。有人建议，超螺旋的自由能促进形成一个开放的复合物的转录起始的转录因子的最小集合。
Immunoglobulin heavy chain (IgH) gene transcription in vitro can be reconstituted with a minimal reaction containing only TATA-binding protein (TBP), TFIIB, and RNA polymerase II (pol II) when the template is negatively supercoiled. Transcription from linear DNA templates containing either the IgH or the adenovirus major late promoters (MLPs) requires in addition TFIIF, TFIIE, TFIIH, and a fraction containing TFIIA and TFIIJ. Promoters vary in their activities in the minimal reaction. Initiation at the adenovirus MLP site was not observed in this reaction, even with templates containing negative superhelical density. When only TBP, TFIIB, and pol II were present in the reaction, the more negatively supercoiled the IgH template DNA was, the more active the transcription. It is suggested that the free energy of supercoiling promotes the formation of an open complex for initiation of transcription by the minimal set of transcription factors.