Centro de Investigaciones Biológicas, Madrid, Spain.
RNA Biol. 2011 Sep-Oct;8(5):760-5. doi: 10.4161/rna.8.5.16021. Epub 2011 Sep 1.
Recent electron cryomicroscopy reconstructions have provided new insights into the overall organization of yeast RNA polymerase (Pol) III, responsible for the synthesis of small, non-translated RNAs. The structure of the free Pol III enzyme at 10 Å resolution provides an accurate framework to better understand its overall architecture and the structural organization and functional role of two Pol III-specific subcomplexes. Cryo-EM structures of elongating Pol III bound to DNA/RNA scaffolds show the rearrangement of the Pol III-specific subcomplexes that enclose incoming DNA. In one reconstruction downstream DNA and newly transcribed RNA can be followed over considerably longer distances as in the crystal structure of elongating Pol II. The Pol III transcription machinery is increasingly recognized as a possible target for cancer therapy. The recent cryo-EM reconstructions contribute to the molecular understanding of Pol III transcription as a prerequisite for targeting its components.
最近的电子冷冻显微镜重建工作为了解酵母 RNA 聚合酶 (Pol) III 的整体组织提供了新的见解，Pol III 负责合成小的非翻译 RNA。10Å 分辨率的游离 Pol III 酶结构为更好地理解其整体结构以及两个 Pol III 特异性亚基复合物的结构组织和功能作用提供了一个准确的框架。与 DNA/RNA 支架结合的延伸 Pol III 的冷冻电镜结构显示出包围进入 DNA 的 Pol III 特异性亚基复合物的重排。在一个重建中，可以像延伸 Pol II 的晶体结构一样，沿着相当长的距离追踪下游 DNA 和新转录的 RNA。Pol III 转录机制越来越被认为是癌症治疗的可能靶点。最近的冷冻电镜重建工作有助于分子理解 Pol III 转录，作为靶向其成分的前提。
