极端嗜热古菌尿嘧啶DNA糖苷酶的研究进展

Research progress of uracil DNA glycosylase from hyperthermophilic archaea

摘要:

高温会加快碱基脱氨基反应形成损伤碱基的速率，进一步对脱氨基的碱基进行复制会导致突变。因此，极端嗜热古菌基因组的稳定性面临着其生存高温环境的挑战。胞嘧啶脱氨基形成尿嘧啶，是常见的脱碱基类型，复制DNA中尿嘧啶会造成GC→AT的突变。尿嘧啶DNA糖苷酶（Uracil DNA glycosylase，UDG）是修复DNA中尿嘧啶的关键酶。基于识别底物的特异性，UDG分为6个家族，广泛分布在细菌、古菌、真核生物以及一些病毒中。基因组序列显示，极端嗜热古菌至少编码一种UDG。目前，对于细菌和真核生物的UDG已进行了大量的研究，但是关于极端嗜热古菌UDG的研究相对较少，尚处于初期阶段。本文综述了极端嗜热古菌UDG的研究进展，并对今后的研究提出了展望。

Abstract:

High temperatures accelerate a rate at which deamination of a base forms a damaged base, and further replication of the deaminated base results in a mutation. Therefore, genomic stability of hyperthermophilic archaea is facing a challenge of high temperature environments in which they survive. Deamination of cytosine to form uracil is a common deaminated type, and the replication of uracil in DNA causes a mutation in GC→AT. Uracil DNA glycosylase (UDG) is a key enzyme in the repair of uracil in DNA. Based on their substrate specificity, UDGs are divided into six families and are widely distributed in bacteria, archaea, eukaryotes, and some viruses. Genomic sequences show that hyperthermophilic archaea encode at least one UDG. Currently, UDGs have been extensively studied for bacteria and eukaryotes, but research on the hyperthermophilic archaea UDGs is relatively rare and is still in its infancy. In this paper, research progress of hyperthermophilic archaea UDGs was reviewed, and their future research was proposed.