Yamtich Jennifer, Sweasy Joann B
Department of Therapeutic Radiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
Biochim Biophys Acta. 2010 May;1804(5):1136-50. doi: 10.1016/j.bbapap.2009.07.008. Epub 2009 Jul 23.
The X family of DNA polymerases in eukaryotic cells consists of terminal transferase and DNA polymerases beta, lambda, and mu. These enzymes have similar structural portraits, yet different biochemical properties, especially in their interactions with DNA. None of these enzymes possesses a proofreading subdomain, and their intrinsic fidelity of DNA synthesis is much lower than that of a polymerase that functions in cellular DNA replication. In this review, we discuss the similarities and differences of three members of Family X: polymerases beta, lambda, and mu. We focus on biochemical mechanisms, structural variation, fidelity and lesion bypass mechanisms, and cellular roles. Remarkably, although these enzymes have similar three-dimensional structures, their biochemical properties and cellular functions differ in important ways that impact cellular function.
真核细胞中的X家族DNA聚合酶由末端转移酶以及DNA聚合酶β、λ和μ组成。这些酶具有相似的结构特征，但生化特性不同，尤其是在与DNA的相互作用方面。这些酶均不具备校对亚结构域，其DNA合成的固有保真度远低于在细胞DNA复制中起作用的聚合酶。在本综述中，我们讨论了X家族的三个成员：聚合酶β、λ和μ的异同。我们重点关注生化机制、结构变异、保真度和损伤旁路机制以及细胞功能。值得注意的是，尽管这些酶具有相似的三维结构，但其生化特性和细胞功能在影响细胞功能的重要方面存在差异。
