真核细胞DNA聚合酶δ的结构与功能

Structure and Function of Eukaryotic DNA Polymeraseδ

DNA聚合酶δ(Polδ)在真核细胞的DNA复制过程中具有核心酶的作用,同时还参与DNA的修复。Polδ是一种由多个亚基组成的复合体,目前已从哺乳动物、裂殖酵母和芽殖酵母等多种真核生物细胞中分离出,并对它们的亚基组成进行了分析,但还未得到确切一致的结果。Polδ在DNA复制中的具体作用已基本了解,它参与催化整个前导链的复制以及一些或大部分滞后链的复制。此外,Polδ还参与DNA的修复,此酶的这一功能可减少DNA的变异,但目前对其作用机理还知之较少。在Polδ活性调控方面,主要研究了一些相关蛋白因子对Polδ活性的调控作用以及转录因子对催化亚基表达的调控作用。

DNA polymerase δ (Polδ) is the core enzyme involved in the replication of DNA in eukaryote cell, and participates in severa DNA repair pathways at the time. Polδ is a complex which is consist of several subunits. It has been now purified from mammalian, Schizosaccharomyces prombe and Saccharomyces cerevisiae and their composition of subunits were analyzed. But it is not known clearly. The general functions of Polδ are recognized now. Polδ plays a role in the replication of the whole leading strand, and it is required for the completion of Okazaki fragment synthesis. Otherwise Polδ is also involved in DNA repair. This function of DNA repair can reduce the mutation of DNA, however, the mechanism is not clear now. In the control of Polδ activation the researchers focus on the regulation of several protein factors on the activation of Polδ and regulation of transcription factors on the expression of the catalytic subunit.