Swanson R N, Conesa C, Lefebvre O, Carles C, Ruet A, Quemeneur E, Gagnon J, Sentenac A
Service de Biochimie et Génétique Moléculaire, Centre d'Etudes Nucléaires de Saclay, Gif sur Yvette, France.
Proc Natl Acad Sci U S A. 1991 Jun 1;88(11):4887-91. doi: 10.1073/pnas.88.11.4887.
Transcription factor TFIIIC mediates tRNA and 5S RNA gene activation by binding to intragenic promoter elements. The factor from Saccharomyces cerevisiae, also called tau, is a large, multisubunit protein (550-650 kDa) containing two polypeptides that interact directly with DNA encoding tRNA (tDNA). We have obtained peptide sequences from the 95-kDa DNA-binding subunit (tau 95) and cloned the corresponding gene, called TFC1. The gene encodes a polypeptide of calculated Mr 73,500. However, when TFC1 was transcribed and translated in vitro, the gene product comigrated with tau 95 in SDS/polyacrylamide gels. A fusion protein expressed in bacteria was able to prevent the binding of anti-tau 95 antibodies to tau-tDNA complexes. The TFC1 gene is present in single copy on yeast chromosome II and is essential for growth. Spores containing a disrupted gene germinate but only proceed through a few cell divisions before ceasing to grow. The TFC1-encoded protein contains a potential helix-turn-helix structure and an acidic carboxyl-terminal domain, a feature characteristic of some DNA-binding proteins and transcriptional regulators.
转录因子TFIIIC通过与基因内启动子元件结合来介导tRNA和5S RNA基因的激活。来自酿酒酵母的该因子，也称为tau，是一种大型多亚基蛋白（550 - 650 kDa），包含两条直接与编码tRNA的DNA（tDNA）相互作用的多肽。我们从95 kDa的DNA结合亚基（tau 95）获得了肽序列，并克隆了相应的基因，称为TFC1。该基因编码一个计算分子量为73,500的多肽。然而，当TFC1在体外进行转录和翻译时，基因产物在SDS/聚丙烯酰胺凝胶中与tau 95迁移一致。在细菌中表达的融合蛋白能够阻止抗tau 95抗体与tau - tDNA复合物的结合。TFC1基因以单拷贝形式存在于酵母II号染色体上，对生长至关重要。含有被破坏基因的孢子能够萌发，但在停止生长之前只能进行几次细胞分裂。TFC1编码的蛋白质含有一个潜在的螺旋 - 转角 - 螺旋结构和一个酸性羧基末端结构域，这是一些DNA结合蛋白和转录调节因子的特征。
