酿酒酵母RNA聚合酶III转录因子TFIIIB的B" 组分编码基因TFC5的克隆、表达及功能

Kassavetis G A, Nguyen S T, Kobayashi R, Kumar A, Geiduschek E P, Pisano M

Department of Biology, University of California at San Diego, La Jolla 92093-0634, USA.

Proc Natl Acad Sci U S A. 1995 Oct 10;92(21):9786-90. doi: 10.1073/pnas.92.21.9786.

TFC5, the unique and essential gene encoding the B" component of the Saccharomyces cerevisiae RNA polymerase III transcription factor (TF)IIIB has been cloned. It encodes a 594-amino acid protein (67,688 Da). Escherichia coli-produced B" has been used to reconstitute entirely recombinant TFIIIB that is fully functional for TFIIIC-directed, as well as TATA box-dependent, DNA binding and transcription. The DNase I footprints of entirely recombinant TFIIIB, composed of B", the 67-kDa Brf, and TATA box-binding protein, and TFIIIB reconstituted with natural B" are indistinguishable. A truncated form of B" lacking 39 N-terminal and 107 C-terminal amino acids is also functional for transcription.

TFC5，即酿酒酵母RNA聚合酶III转录因子（TF）IIIB的B" 组分的唯一必需基因已被克隆。它编码一个594个氨基酸的蛋白质（67,688道尔顿）。大肠杆菌产生的B" 已被用于完全重组功能性TFIIIB的重构，该重组TFIIIB对TFIIIC指导的以及TATA框依赖性的DNA结合和转录均具有完全功能。由B"、67 kDa的Brf和TATA框结合蛋白组成的完全重组TFIIIB的DNase I足迹与用天然B" 重构的TFIIIB的足迹无法区分。缺少39个N端和107个C端氨基酸的B" 截短形式对转录也具有功能。