Jawhari Anass, Uhring Muriel, De Carlo Sacha, Crucifix Corinne, Tocchini-Valentini Guiseppe, Moras Dino, Schultz Patrick, Poterszman Arnaud
Department of Structural Biology and Genomics, Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, rue Laurent Fries, 67404 Illkirch, France.
EMBO Rep. 2006 May;7(5):500-5. doi: 10.1038/sj.embor.7400663. Epub 2006 Mar 17.
The general RNA polymerase II transcription factor TFIIE, which is composed of two subunits, has essential roles in both transcription initiation and promoter escape. Electron microscopy analysis of negatively stained human TFIIE showed a large proportion of alpha/beta heterodimers as well as a small proportion of tetramers. Analytical ultracentrifugation, chemical crosslinking, pulldown experiments and cryo-electron microscopy confirmed that TFIIE is a alpha/beta heterodimer in solution. Three-dimensional envelopes of the alpha/beta particles showed an elongated structure composed of three distinct modules. Finally, a model for the quaternary architecture of the complex is proposed that provides a structural framework to discuss the function of TFIIE in the context of RNA polymerase II transcription initiation.
一般的RNA聚合酶II转录因子TFIIE由两个亚基组成,在转录起始和启动子逃逸过程中都起着至关重要的作用。对负染的人TFIIE进行电子显微镜分析显示,大部分为α/β异二聚体,还有一小部分为四聚体。分析超速离心、化学交联、下拉实验和冷冻电子显微镜证实,TFIIE在溶液中是α/β异二聚体。α/β颗粒的三维包络显示出由三个不同模块组成的细长结构。最后,提出了该复合物四级结构的模型,为在RNA聚合酶II转录起始背景下讨论TFIIE的功能提供了一个结构框架。