Dieckman Lynne M, Freudenthal Bret D, Washington M Todd
Department of Biochemistry, University of Iowa College of Medicine, Iowa City, IA, 52242-1109, USA.
Subcell Biochem. 2012;62:281-99. doi: 10.1007/978-94-007-4572-8_15.
Proliferating cell nuclear antigen (PCNA), the eukaryotic DNA sliding clamp, forms a ring-shaped homo-trimer that encircles double-stranded DNA. This protein is best known for its ability to confer high processivity to replicative DNA polymerases. However, it does far more than this, because it forms a mobile platform on the DNA that recruits many of the proteins involved in DNA replication, repair, and recombination to replication forks. X-ray crystal structures of PCNA bound to PCNA-binding proteins have provided insights into how PCNA recognizes its binding partners and recruits them to replication forks. More recently, X-ray crystal structures of ubiquitin-modified and SUMO-modified PCNA have provided insights into how these post-translational modifications alter the specificity of PCNA for some of its binding partners. This article focuses on the insights gained from structural studies of PCNA complexes and post-translationally modified PCNA.
增殖细胞核抗原（PCNA）是真核生物的DNA滑动夹，它形成一个环绕双链DNA的环状同型三聚体。这种蛋白质最为人所知的是其赋予复制性DNA聚合酶高持续合成能力的能力。然而，它的作用远不止于此，因为它在DNA上形成了一个移动平台，可将许多参与DNA复制、修复和重组的蛋白质招募到复制叉处。与PCNA结合蛋白结合的PCNA的X射线晶体结构，为PCNA如何识别其结合伙伴并将它们招募到复制叉处提供了见解。最近，泛素修饰和SUMO修饰的PCNA的X射线晶体结构，为这些翻译后修饰如何改变PCNA对其一些结合伙伴的特异性提供了见解。本文重点介绍从PCNA复合物的结构研究以及翻译后修饰的PCNA中获得的见解。
