Segall J, Matsui T, Roeder R G
J Biol Chem. 1980 Dec 25;255(24):11986-91.
Cell-free extracts (S-100) prepared from cultured mammalian KB cells have previously been shown to direct accurate and selective transcription of class III genes by RNA polymerase III. We have fractionated the KB S-100 and have found that multiple components are essential for the accurate transcription of these genes. After the S-100 has been separated into four different protein fractions by chromatography on phosphocellulose, two fractions are required, in addition to RNA polymerase III, for active and selective transcription of the virus-associated RNAI gene of adenovirus 2 and a tRNA gene; a third fraction is required, along with these components, for the reconstitution of 5 S RNA gene transcription. At least two of these components are distinct from the four factors required for accurate initiation of transcription by RNA polymerase II (Matsui, T., Segall, J., Weil, P. A., and Roeder, R. G. (1980) J. Biol. Chem. 255, 11992-11996).
先前已表明，从培养的哺乳动物KB细胞制备的无细胞提取物（S-100）可通过RNA聚合酶III指导III类基因进行准确且选择性的转录。我们对KB S-100进行了分级分离，发现多个组分对于这些基因的准确转录至关重要。通过磷酸纤维素柱层析将S-100分离成四个不同的蛋白质组分后，除RNA聚合酶III外，还需要两个组分才能对腺病毒2的病毒相关RNAI基因和一个tRNA基因进行活性和选择性转录；对于5S RNA基因转录的重建，除了这些组分外，还需要第三个组分。这些组分中至少有两个不同于RNA聚合酶II准确起始转录所需的四种因子（松井，T.，西格尔，J.，韦尔，P.A.，和罗德，R.G.（1980年）《生物化学杂志》255，11992 - 11996）。
