A REPAIR SYSTEM FOR 8-OXO-7,8-DIHYDRODEOXYGUANINE
A REPAIR SYSTEM FOR 8-OXO-7,8-DIHYDRODEOXYGUANINE
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DOI：
10.1021/bi00160a004
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发表时间：
1992-11-17
期刊：
影响因子：
2.9
通讯作者：
MILLER, JH
中科院分区：
文献类型：
--
作者：
MICHAELS, ML;TCHOU, J;MILLER, JH
活性氧物种可以损伤DNA，并可能在衰老和癌症发生中发挥作用。我们测试了MutY糖基酶在未受损的错对以及与氧化损伤的底物8-氧-7，8-二氢脱氧鸟嘌呤(GO)或8-氧-7，8-二氢脱氧腺嘌呤(AO)形成的错对上的活性。MutY在被测试的A/G、A/GO、A/C和A/AO四种异源双链上起糖基酶的作用，从每个底物上去除未受损的腺嘌呤。遗传学数据表明，体内MutY糖基酶的主要底物是A/GO错对。我们提出的生化证据表明，MutY糖基酶是包括MutM和Mutt蛋白在内的修复系统的重要组成部分。GO修复系统致力于修复氧化损伤的鸟嘌呤及其引发的突变。
Active oxygen species can damage DNA and may play a role in aging and carcinogenesis. We have tested MutY glycosylase for activity on undamaged mispairs as well as mispairs formed with the oxidatively damaged substrates, 8-oxo-7,8-dihydrodeoxyguanine (GO) or 8-oxo-7,8-dihydrodeoxyadenine (AO). MutY acts as a glycosylase on four of the heteroduplexes tested, A/G, A/GO, A/C, and A/AO, removing the undamaged adenine from each substrate. Genetic data suggest that the primary substrate for MutY glycosylase in vivo is the A/GO mispair. We present biochemical evidence demonstrating that MutY glycosylase is an important part of a repair system that includes the MutM and MutT proteins. The GO repair system is dedicated to the repair of the oxidatively damaged guanine and the mutations it can induce.