The eukaryotic RNA polymerases Pol I, Pol II, and Pol III are the central multiprotein machines that synthesize ribosomal, messenger, and transfer RNA, respectively. Here we provide a catalog of available structural information for these three enzymes. Most structural data have been accumulated for Pol II and its functional complexes. These studies have provided insights into many aspects of the transcription mechanism, including initiation at promoter DNA, elongation of the mRNA chain, tunability of the polymerase active site, which supports RNA synthesis and cleavage, and the response of Pol II to DNA lesions. Detailed structural studies of Pol I and Pol III were reported recently and showed that the active center region and core enzymes are similar to Pol II and that strong structural differences on the surfaces account for gene class-specific functions.

中文翻译：

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真核RNA聚合酶的结构。

真核RNA聚合酶Pol I，Pol II和Pol III是分别合成核糖体，信使和转移RNA的主要多蛋白机器。在这里，我们提供了这三种酶的可用结构信息的目录。Pol II及其功能复合物的大部分结构数据已被积累。这些研究为转录机制的许多方面提供了见识，包括启动子DNA的起始，mRNA链的延长，聚合酶活性位点的可调性（支持RNA合成和裂解）以及Pol II对DNA损伤的反应。