Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio, Spain.
Biochem Soc Trans. 2013 Feb 1;41(1):356-61. doi: 10.1042/BST20120305.
In recent years, emerging structural information on the aRNAP (archaeal RNA polymerase) apparatus has shown its strong evolutionary relationship with the eukaryotic counterpart, RNA Pol (polymerase) II. A novel atomic model of SshRNAP (Sulfolobus shibatae RNAP) in complex with dsDNA (double-stranded DNA) constitutes a new piece of information helping the understanding of the mechanisms for DNA stabilization at the position downstream of the catalytic site during transcription. In Archaea, in contrast with Eukarya, downstream DNA stabilization is universally mediated by the jaw domain and, in some species, by the additional presence of the Rpo13 subunit. Biochemical and biophysical data, combined with X-ray structures of apo- and DNA-bound aRNAP, have demonstrated the capability of the Rpo13 C-terminus to bind in a sequence-independent manner to downstream DNA. In the present review, we discuss the recent findings on the aRNAP and focus on the mechanisms by which the RNAP stabilizes the bound DNA during transcription.
近年来，关于 aRNAP（古菌 RNA 聚合酶）装置的新兴结构信息表明，它与真核生物对应物 RNA Pol（聚合酶）II 具有很强的进化关系。与 dsDNA（双链 DNA）结合的 SshRNAP（Sulfolobus shibatae RNAP）的新型原子模型构成了有助于理解在转录过程中催化位点下游位置处 DNA 稳定的机制的新信息。在古菌中，与真核生物相反，下游 DNA 的稳定普遍由 Jaw 结构域介导，并且在某些物种中，由额外存在的 Rpo13 亚基介导。生化和生物物理数据，结合无蛋白和 DNA 结合的 aRNAP 的 X 射线结构，已经证明了 Rpo13 C 末端以序列非依赖性方式与下游 DNA 结合的能力。在本综述中，我们讨论了关于 aRNAP 的最新发现，并重点讨论了 RNA 聚合酶在转录过程中稳定结合 DNA 的机制。
