Olmsted V K, Awrey D E, Koth C, Shan X, Morin P E, Kazanis S, Edwards A M, Arrowsmith C H
Ontario Cancer Institute and Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5G 2M9, Canada.
J Biol Chem. 1998 Aug 28;273(35):22589-94. doi: 10.1074/jbc.273.35.22589.
TFIIS is a general transcription elongation factor that helps arrested RNA polymerase II elongation complexes resume transcription. We have previously shown that yeast TFIIS (yTFIIS) comprises three structural domains (I-III). The three-dimensional structures of domain II and part of domain III have been previously reported, but neither domain can autonomously stimulate transcription elongation. Here we report the NMR structural analysis of residues 131-309 of yTFIIS which retains full activity and contains all of domains II and III. We confirm that the structure of domain II in the context of fully active yTFIIS is the same as that determined previously for a shorter construct. We have determined the structure of the C-terminal zinc ribbon domain of active yTFIIS and shown that it is similar to that reported for a shorter construct of human TFIIS. The region linking domain II with the zinc ribbon of domain III appears to be conformationally flexible and does not adopt a single defined tertiary structure. NMR analysis of inactive mutants of yTFIIS support a role for the linker region in interactions with the transcription elongation complex.
TFIIS是一种通用转录延伸因子，可帮助停滞的RNA聚合酶II延伸复合物恢复转录。我们之前已经表明，酵母TFIIS（yTFIIS）由三个结构域（I-III）组成。结构域II和结构域III的一部分的三维结构先前已有报道，但这两个结构域都不能自主刺激转录延伸。在此，我们报告了yTFIIS中131-309位残基的核磁共振结构分析，该区域保留了全部活性，并且包含所有的结构域II和结构域III。我们证实，在完全活性的yTFIIS背景下，结构域II的结构与先前针对较短构建体所确定的结构相同。我们已经确定了活性yTFIIS的C端锌带结构域的结构，并表明它与报道的人TFIIS较短构建体的结构相似。连接结构域II与结构域III锌带的区域似乎在构象上具有灵活性，并且不采用单一确定的三级结构。yTFIIS无活性突变体的核磁共振分析支持连接区域在与转录延伸复合物相互作用中的作用。
