REPAIR OF 8-HYDROXYGUANINE IN DNA BY MAMMALIAN N-METHYLPURINE-DNA GLYCOSYLASE
REPAIR OF 8-HYDROXYGUANINE IN DNA BY MAMMALIAN N-METHYLPURINE-DNA GLYCOSYLASE
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DOI：
10.1073/pnas.90.19.8901
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发表时间：
1993-10-01
影响因子：
11.1
通讯作者：
MITRA, S
中科院分区：
文献类型：
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作者：
BESSHO, T;ROY, R;MITRA, S
8-羟基鸟嘌呤是电离辐射和拟辐射物质诱发突变的主要碱基损伤之一。这种损伤似乎是由人类细胞通过多种途径修复的，包括涉及基础糖基化酶的途径。小鼠N-甲基嘌呤-DNA糖基化酶，负责去除DNA中的N-烷基嘌呤，由简单的单功能烷化剂诱导，也释放8-羟基鸟嘌呤从DNA在体外和体内在大肠杆菌。人N-甲基嘌呤-DNA糖基化酶对N-烷基鸟嘌呤的偏好低于小鼠蛋白，其去除氧化碱基的效率低于小鼠蛋白。重组哺乳动物糖基化酶能拯救E.大肠杆菌缺乏MutM（Fpg）蛋白，该蛋白是主要负责从细菌DNA中去除8-羟基鸟嘌呤的DNA糖基化酶。
8-Hydroxyguanine is one of the major base lesions implicated in mutagenesis induced by ionizing radiation and radiomimetic agents. This lesion appears to be repaired by human cells via multiple pathways including the one that involves a base glycosylase. Mouse N-methylpurine-DNA glycosylase, responsible for the removal of N-alkylpurines in DNA that are induced by simple monofunctional alkylating agents, also releases 8-hydroxyguanine from DNA in vitro and in vivo in Escherichia coli. The human N-methylpurine-DNA glycosylase, with a lower preference for N-alkylguanine than the mouse protein, removes the oxidized base less efficiently than the mouse protein. The recombinant mammalian glycosylases can rescue E. coli lacking MutM (Fpg) protein, the DNA glycosylase that is primarily responsible for removing 8-hydroxyguanine from the bacterial DNA.