Murphy S, Tripodi M, Melli M
Nucleic Acids Res. 1986 Dec 9;14(23):9243-60. doi: 10.1093/nar/14.23.9243.
We have isolated and characterized two recombinant lambda phages containing sequences homologous to 7SK RNA which code for a RNA 330 nucleotides long in an "in vitro" transcription system. S1 mapping of the transcript shows that this RNA corresponds to the 7SK RNA obtained from human cells, indicating that the two recombinant phages contain genes coding for 7SK RNA. The transcription of these genes is polymerase III dependent. Sequences upstream from the start of transcription are essential for "in vitro" synthesis of 7SK RNA, suggesting that internal promoter elements, if present, are not sufficient to support the synthesis of 7SK RNA. A region of homology with the upstream sequences of the genes for U6 RNA, 7SL RNA and Bombyx mori alanine tRNA is found within 50 bp from the transcription start point. Within the homologous region a motif common to the four genes is a "TATA"-like box, placed at position -30 to -25 of the 7SK RNA gene, which is typical of the polymerase II promoter region.
我们已经分离并鉴定了两个重组λ噬菌体，它们含有与7SK RNA同源的序列，这些序列在“体外”转录系统中编码一种长度为330个核苷酸的RNA。对转录本的S1图谱分析表明，这种RNA与从人细胞中获得的7SK RNA相对应，这表明这两个重组噬菌体含有编码7SK RNA的基因。这些基因的转录依赖于聚合酶III。转录起始点上游的序列对于7SK RNA的“体外”合成至关重要，这表明如果存在内部启动子元件，它们不足以支持7SK RNA的合成。在距转录起始点50 bp范围内发现了与U6 RNA、7SL RNA和家蚕丙氨酸tRNA基因上游序列的同源区域。在同源区域内，这四个基因共有的一个基序是一个“TATA”样框，位于7SK RNA基因的-30至-25位，这是聚合酶II启动子区域的典型特征。
