Kleinert H, Gladen A, Geisler M, Benecke B J
Department of Biochemistry, Ruhr-University, Bochum, Federal Republic of Germany.
J Biol Chem. 1988 Aug 15;263(23):11511-5.
Two functional human genes coding for 7 S RNA species K and L were analyzed for promoter requirements by in vitro transcription experiments with cytoplasmic S-100 extracts. Since accurate and efficient transcription of both genes is dependent on the presence of 5'-flanking sequences, hybrid genes representing crossover fusions between the 5' external control regions and the coding sequences of both genes were analyzed for their capacity to direct RNA synthesis in vitro. Differing results were obtained with both types of constructs. While the 5'-flanking L-7 S K gene fusion revealed no activity in the in vitro transcription assay, the 5'-flanking sequence of the 7 S K RNA gene did confer the ability for accurate in vitro transcription to the 7 S L coding sequence. However, a 5'-flanking L sequence element including the first 22 nucleotides of the 7 S L RNA coding sequence was active in promoting transcription of the 7 S K RNA gene. Together, these results demonstrated that the 7 S L promoter is located inside and outside the coding region, whereas the 7 S K RNA gene is exclusively controlled by an upstream promoter element.
通过利用细胞质S-100提取物进行体外转录实验，对编码7S RNA种类K和L的两个功能性人类基因的启动子需求进行了分析。由于这两个基因的准确和高效转录均依赖于5'侧翼序列的存在，因此对代表5'外部控制区域与两个基因编码序列之间交叉融合的杂交基因进行了体外指导RNA合成能力的分析。两种类型的构建体得到了不同的结果。虽然5'侧翼L-7S K基因融合在体外转录测定中未显示活性，但7S K RNA基因的5'侧翼序列确实赋予了7S L编码序列进行准确体外转录的能力。然而，一个包含7S L RNA编码序列前22个核苷酸的5'侧翼L序列元件在促进7S K RNA基因转录方面具有活性。总之，这些结果表明7S L启动子位于编码区域的内部和外部，而7S K RNA基因仅由上游启动子元件控制。
