Baute Joke, Depicker Anne
Department of Plant Systems Biology, Flanders Institute for Biotechnology, Gent, Belgium.
Crit Rev Biochem Mol Biol. 2008 Jul-Aug;43(4):239-76. doi: 10.1080/10409230802309905.
For all living organisms, genome stability is important, but is also under constant threat because various environmental and endogenous damaging agents can modify the structural properties of DNA bases. As a defense, organisms have developed different DNA repair pathways. Base excision repair (BER) is the predominant pathway for coping with a broad range of small lesions resulting from oxidation, alkylation, and deamination, which modify individual bases without large effect on the double helix structure. As, in mammalian cells, this damage is estimated to account daily for 10(4) events per cell, the need for BER pathways is unquestionable. The damage-specific removal is carried out by a considerable group of enzymes, designated as DNA glycosylases. Each DNA glycosylase has its unique specificity and many of them are ubiquitous in microorganisms, mammals, and plants. Here, we review the importance of the BER pathway and we focus on the different roles of DNA glycosylases in various organisms.
对于所有生物而言，基因组稳定性至关重要，但同时也时刻面临威胁，因为各种环境和内源性损伤因子会改变DNA碱基的结构特性。作为一种防御机制，生物进化出了不同的DNA修复途径。碱基切除修复（BER）是应对由氧化、烷基化和脱氨作用导致的多种小损伤的主要途径，这些损伤会修饰单个碱基，而对双螺旋结构影响不大。在哺乳动物细胞中，据估计这种损伤每天每个细胞会发生10⁴次，因此BER途径的必要性毋庸置疑。损伤特异性去除是由一大类被称为DNA糖基化酶的酶来完成的。每种DNA糖基化酶都有其独特的特异性，其中许多在微生物、哺乳动物和植物中普遍存在。在此，我们综述BER途径的重要性，并聚焦于DNA糖基化酶在各种生物中的不同作用。
