Romaniuk P J
Department of Biochemistry and Microbiology, University of Victoria, BC, Canada.
Biochemistry. 1989 Feb 7;28(3):1388-95. doi: 10.1021/bi00429a067.
The role of highly conserved single-stranded sequence elements of Xenopus 5S RNA in the binding of transcription factor IIIA (TFIIIA) was studied. A series of mutant 5S RNA genes were constructed with defined block sequence changes in regions corresponding to each of the single-stranded loops of the transcribed 5S RNA. The interaction of the resulting mutant 5S RNA molecules with TFIIIA was determined both by a direct binding assay and by a competition assay. With one exception, the substitution of highly conserved single-stranded loop sequences had only a modest effect on the binding of TFIIIA. The single exception was loop A, which ironically is not part of the protected site of TFIIIA on 5S RNA. The possible involvement of loop A in the coaxial stacking of the helical domains of 5S RNA, and how this might affect TFIIIA binding, are discussed.
研究了非洲爪蟾5S RNA高度保守的单链序列元件在转录因子IIIA（TFIIIA）结合中的作用。构建了一系列突变5S RNA基因，这些基因在与转录的5S RNA的每个单链环相对应的区域具有确定的块状序列变化。通过直接结合试验和竞争试验确定了所得突变5S RNA分子与TFIIIA的相互作用。除了一个例外，高度保守的单链环序列的替换对TFIIIA的结合只有适度的影响。唯一的例外是环A，具有讽刺意味的是，它不是TFIIIA在5S RNA上的保护位点的一部分。讨论了环A可能参与5S RNA螺旋结构域的同轴堆积以及这可能如何影响TFIIIA结合。
