Hübner P, Iida S, Arber W
Mol Gen Genet. 1987 Mar;206(3):485-90. doi: 10.1007/BF00428889.
The prokaryotic transposable element IS1 is known to exert a strong polar effect upon integration into an operon. To elucidate this polar effect, we constructed a plasmid which has an IS1 integrated between the 5' half of the tet gene for tetracycline resistance and the cat structural gene for chloramphenicol resistance. The cat gene is expressed by the tet promoter and the presence of IS1 in orientation I, in which the IS1 transposase genes insA and insB are in the same orientation as the cat gene, reduced the cat expression. By introducing deletions or insertions within the IS1 sequence, we were able to map a rho-dependent terminator TIS1A between the insA and insB genes. Translational interruption between these ins genes is important for TIS1A to be an active terminator.
已知原核转座因子IS1整合到操纵子中时会产生强烈的极性效应。为阐明这种极性效应，我们构建了一个质粒，该质粒的IS1整合在四环素抗性tet基因的5'端半段与氯霉素抗性cat结构基因之间。cat基因由tet启动子表达，当IS1以方向I存在时（其中IS1转座酶基因insA和insB与cat基因同向），cat表达降低。通过在IS1序列内引入缺失或插入，我们能够在insA和insB基因之间定位到一个依赖于rho的终止子TIS1A。这些ins基因之间的翻译中断对于TIS1A成为一个活性终止子很重要。
