Shastry B S
Eye Research Institute, Oakland University, Rochester, Michigan 48309.
Experientia. 1993 Oct 15;49(10):831-5. doi: 10.1007/BF01952592.
Xenopus transcription factor, termed TFIIIA, is the first eukaryotic transcription factor purified to homogeneity and one of the most extensively characterized polymerase III gene factors at the levels both of the protein and its gene. It is an abundant protein in oocytes and is specifically required for the 5S RNA gene transcription. It promotes the formation of a stable transcription complex by first binding to the internal control region of the 5S RNA gene through its zinc finger motifs. It contains two structural domains and associates with 5S RNA to form 7S ribonucleoprotein particles in oocytes. Its expression is developmentally controlled at the level of transcription and translation. It participates in the assembly of active chromatin templates and, at least in part, is responsible for the differential expression of two kinds of 5S RNA genes in Xenopus.
非洲爪蟾转录因子，称为TFIIIA，是第一个被纯化至同质的真核转录因子，也是在蛋白质及其基因水平上研究最为广泛的聚合酶III基因因子之一。它是卵母细胞中的一种丰富蛋白质，是5S RNA基因转录所特需的。它首先通过其锌指基序与5S RNA基因的内部控制区域结合，从而促进稳定转录复合物的形成。它包含两个结构域，并在卵母细胞中与5S RNA结合形成7S核糖核蛋白颗粒。其表达在转录和翻译水平上受到发育调控。它参与活性染色质模板的组装，并且至少部分负责非洲爪蟾中两种5S RNA基因的差异表达。
