Campbell F E, Setzer D R
Department of Molecular Biology and Microbiology, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106.
Mol Cell Biol. 1991 Aug;11(8):3978-86. doi: 10.1128/mcb.11.8.3978-3986.1991.
In the absence of other components of the RNA polymerase III transcription machinery, transcription factor IIIA (TFIIIA) can be displaced from both strands of its DNA-binding site (the internal control region) on the somatic-type 5S rRNA gene of Xenopus borealis during transcription elongation by bacteriophage T7 RNA polymerase, regardless of which DNA strand is transcribed. Furthermore, substantial displacement is observed after the template has been transcribed only once. Since the complete 5S rRNA transcription complex has previously been shown to remain stably bound to the gene during repeated rounds of transcription by either RNA polymerase III or bacteriophage SP6 RNA polymerase, these results indicate that a factor(s) in addition to TFIIIA is required to create a complex that will remain stably associated with the template during transcription. Thus, transcription complex stability during passage of RNA polymerase cannot be explained solely on the basis of the DNA-binding properties of TFIIIA.
在缺乏RNA聚合酶III转录机制的其他组分时，在非洲爪蟾体细胞型5S rRNA基因的DNA结合位点（内部控制区）的两条链上，转录因子IIIA（TFIIIA）在噬菌体T7 RNA聚合酶转录延伸过程中可被置换，无论转录的是哪条DNA链。此外，在模板仅被转录一次后就观察到了大量的置换。由于之前已表明完整的5S rRNA转录复合物在RNA聚合酶III或噬菌体SP6 RNA聚合酶的重复转录轮次中会稳定地结合在基因上，这些结果表明，除了TFIIIA之外，还需要一种因子来形成在转录过程中与模板稳定结合的复合物。因此，RNA聚合酶通过时转录复合物的稳定性不能仅基于TFIIIA的DNA结合特性来解释。
