Kaufman P D, Rio D C
Whitehead Institute for Biomedical Research, Nine Cambridge Center, MA 02142.
Proc Natl Acad Sci U S A. 1991 Apr 1;88(7):2613-7. doi: 10.1073/pnas.88.7.2613.
Mobility of P transposable elements in Drosophila melanogaster depends on the 87-kDa transposase protein encoded by the P element. Transposase recognizes a 10-base-pair DNA sequence that overlaps an A + T-rich region essential for transcription from the P-element promoter. We report here that transposase represses transcription from the P-element promoter in vitro. This transcriptional repression is blocked by prior formation of an RNA polymerase II transcription complex on the template DNA. Binding of transposase on the P-element promoter is blocked by prior binding of either the Drosophila RNA polymerase II complex or the yeast transcription factor TFIID. These data suggest that transposase represses transcription by preventing assembly of an RNA polymerase II complex at the P-element promoter.
黑腹果蝇中P转座因子的移动性取决于P因子编码的87千道尔顿转座酶蛋白。转座酶识别一个10个碱基对的DNA序列，该序列与P因子启动子转录所必需的富含A+T的区域重叠。我们在此报告，转座酶在体外抑制P因子启动子的转录。这种转录抑制被模板DNA上预先形成的RNA聚合酶II转录复合物所阻断。果蝇RNA聚合酶II复合物或酵母转录因子TFIID的预先结合会阻断转座酶在P因子启动子上的结合。这些数据表明，转座酶通过阻止RNA聚合酶II复合物在P因子启动子处组装来抑制转录。
