Resolution of human transcription factor TFIIIC into two functional components.
Resolution of human transcription factor TFIIIC into two functional components.
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将人类转录因子 TFIIIC 解析为两个功能成分。
DOI：
10.1073/pnas.84.11.3585
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发表时间：
1987
影响因子：
11.1
通讯作者：
Berk,AJ
中科院分区：
文献类型：
--
作者：
Yoshinaga,SK;Boulanger,PA;Berk,AJ
tRNA基因和腺病毒相关（VA）基因由RNA聚合酶III转录。这些基因的体外转录需要两种蛋白质组分，除了RNA聚合酶III外，还含有命名为TFIIIB和TFIIIC的转录因子。我们报告说，TFIIIC馏分来自人类细胞培养中可以分为两个功能组件，我们称之为TFIIIC 1和TFIIIC 2。TFIIIC 1和TFIIIC 2组分都是VA 1基因体外转录所需的。在DNA酶I“足迹”实验中，TFIIIC 2部分保护称为B块的内部控制区。TFIIIC 1组分的添加扩展了称为A区的内部控制区域的足迹。TFIIIC 1活性是粗提物中VA 1转录所需的限制性转录因子活性。TFIIIC 2活性沉积物为约18 S的大组分，而TFIIIC 1活性沉积物为约9 S。这些数据表明，这两项活动是独特的组成部分，如果加在一起，就构成了TFIIIC活动。
tRNA genes and adenovirus viral-associated (VA) genes are transcribed by RNA polymerase III. Transcription of these genes in vitro requires two protein fractions containing transcription factors designated TFIIIB and TFIIIC, in addition to RNA polymerase III. We report that the TFIIIC fraction derived from human cells in culture can be separated into two functional components, which we call TFIIIC1 and TFIIIC2. Both TFIIIC1 and TFIIIC2 fractions are required for in vitro transcription of the VA1 gene. In DNase I "footprinting" experiments, the TFIIIC2 fraction protects the internal control region termed the B block. Addition of the TFIIIC1 fraction extends the footprint over the internal control region called the A block. TFIIIC1 activity is the limiting transcription factor activity required for VA1 transcription in the crude extract. TFIIIC2 activity sediments as a large component of approximately 18 S, while TFIIIC1 activity sediments at approximately 9 S. These data indicate that the two activities are unique components and when added together reconstitute TFIIIC activity.