Friedberg Errol C, Wagner Robert, Radman Miroslav
Laboratory of Molecular Pathology, Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
Science. 2002 May 31;296(5573):1627-30. doi: 10.1126/science.1070236.
Cell death caused by arrested replication of damaged or structurally altered DNA can be avoided in prokaryotic and eukaryotic cells by multiple DNA polymerases that are specialized to bypass DNA damage. Some of these polymerases perform such translesion DNA synthesis of specific types of damage with high genetic fidelity. However, they exhibit greatly reduced fidelity when they operate on undamaged DNA or on DNA with lesions that are (apparently) not cognate substrates. The low fidelity of some of these specialized polymerases when copying undamaged DNA may be physiologically functional, including generating immunoglobulin diversity.
在原核细胞和真核细胞中，受损或结构改变的DNA复制受阻所导致的细胞死亡可通过多种专门用于绕过DNA损伤的DNA聚合酶来避免。其中一些聚合酶能以高遗传保真度对特定类型的损伤进行这种跨损伤DNA合成。然而，当它们作用于未受损的DNA或（显然）不是同源底物的损伤DNA时，保真度会大大降低。这些专门聚合酶中的一些在复制未受损DNA时的低保真度可能具有生理功能，包括产生免疫球蛋白多样性。
