Replicative DNA Polymerases
Replicative DNA Polymerases
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DOI：
10.1101/cshperspect.a012799
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发表时间：
2013-06-01
影响因子：
7.2
通讯作者：
Dixon, Nicholas
中科院分区：
文献类型：
--
作者：
Johansson, Erik;Dixon, Nicholas
1959年，亚瑟·科恩伯格因其在DNA聚合酶复制DNA的原理方面的工作而获得诺贝尔奖。从那时起，在生命的所有分支中都证实了复制型DNA聚合酶需要单链模板来构建互补链，但它们不能从头开始一条新的DNA链。因此，它们还依赖于引物酶，其通常组装短RNA引物以提供可通过复制型DNA聚合酶延伸的3 '-OH。解旋酶解旋双链DNA，单链DNA结合蛋白稳定单链DNA，引物酶构建短RNA引物，以及钳加载器加载钳以（5）促进复制聚合酶的加载和持续合成能力的一般原理在所有物种中都很保守。基因组的复制非常稳健，即使在极端环境中也能高保真地进行。在过去十年左右的工作已经证实：（6）构建DNA链的核苷酸转移酶反应存在一种常见的双金属离子促进机制;（7）复制型DNA聚合酶总是作为更大的多蛋白组装体（称为复制体）的关键组分。此外（8），复制体的完整性是通过多种蛋白质-蛋白质和蛋白质-DNA相互作用来维持的，其中许多相互作用本身就很弱。这使得能够在不解离复制体组分的情况下发生大的构象变化，并且还意味着通常复制体不能完整地分离。
In 1959, Arthur Kornberg was awarded the Nobel Prize for his work on the principles by which DNA is duplicated by DNA polymerases. Since then, it has been confirmed in all branches of life that replicative DNA polymerases require a single-stranded template to build a complementary strand, but they cannot start a new DNA strand de novo. Thus, they also depend on a primase, which generally assembles a short RNA primer to provide a 3'-OH that can be extended by the replicative DNA polymerase. The general principles that (1) a helicase unwinds the double-stranded DNA, (2) single-stranded DNA-binding proteins stabilize the single-stranded DNA, (3) a primase builds a short RNA primer, and (4) a clamp loader loads a clamp to (5) facilitate the loading and processivity of the replicative polymerase, are well conserved among all species. Replication of the genome is remarkably robust and is performed with high fidelity even in extreme environments. Work over the last decade or so has confirmed (6) that a common two-metal ion-promoted mechanism exists for the nucleotidyltransferase reaction that builds DNA strands, and (7) that the replicative DNA polymerases always act as a key component of larger multiprotein assemblies, termed replisomes. Furthermore (8), the integrity of replisomes is maintained by multiple protein-protein and protein-DNA interactions, many of which are inherently weak. This enables large conformational changes to occur without dissociation of replisome components, and also means that in general replisomes cannot be isolated intact.