Structural Biology Program, Sloan-Kettering Institute, New York, New York, USA.
Adv Exp Med Biol. 2011;702:9-28. doi: 10.1007/978-1-4419-7841-7_2.
A large body of structural work conducted over the past ten years has elucidated mechanistic details related to 3' to 5' processing and decay of RNA substrates by the RNA exosome. This chapter will focus on the structural organization of eukaryotic exosomes and their evolutionary cousins in bacteria and archaea with an emphasis on mechanistic details related to substrate recognition and to 3' to 5' phosphorolytic exoribonucleolytic activities of bacterial and archaeal exosomes as well as the hydrolytic exoribonucleolytic and endoribonucleolytic activities of eukaryotic exosomes. These points will be addressed in large part through presentation of crystal structures of phosphorolytic enzymes such as bacterial RNase PH, PNPase and archaeal exosomes and crystal structures of the eukaryotic exosome and exosome sub-complexes in addition to standalone structures of proteins that catalyze activities associated with the eukaryotic RNA exosome, namely Rrp44, Rrp6 and their bacterial counterparts.
在过去的十年中，大量的结构研究阐明了与 RNA 外切体的 3' 到 5' 加工和 RNA 底物降解相关的机制细节。本章将重点介绍真核外切体及其在细菌和古菌中的进化同源体的结构组织，重点介绍与底物识别以及细菌和古菌外切体的 3' 到 5' 磷酸解外切核糖核酸酶活性以及真核外切体的水解外切核糖核酸酶和内切核糖核酸酶活性相关的机制细节。这些观点将主要通过展示磷酸解酶的晶体结构来解决，例如细菌 RNase PH、PNPase 和古菌外切体，以及真核外切体和外切体亚复合物的晶体结构，此外还有催化与真核 RNA 外切体相关活性的蛋白质的独立结构，即 Rrp44、Rrp6 及其细菌对应物。
