Deoxyxanthosine in DNA is repaired by Escherichia coli endonuclease V
Deoxyxanthosine in DNA is repaired by Escherichia coli endonuclease V
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DOI：
10.1016/s0921-8777(99)00063-4
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发表时间：
2000-03-20
期刊：
影响因子：
--
通讯作者：
Kow, YW
中科院分区：
文献类型：
--
作者：
He, B;Qing, H;Kow, YW
脱氧胞苷、脱氧腺苷和脱氧鸟苷分别发生自发脱胺反应生成脱氧尿苷、脱氧肌苷和脱氧黄嘌呤。在这篇手稿中，我们证明了除了识别DNA中的脱氧尿苷和脱氧肌苷的已知能力外，大肠杆菌内切酶V还能切割含有脱氧黄嘌呤的DNA。然而，ALK A蛋白和人甲基嘌呤糖基酶不能识别脱氧黄嘌呤。核酸内切酶V在第二个磷酸二酯键3‘将含有脱氧黄嘌呤的DNA裂解成脱氧黄嘌呤，在缺口处产生一个3’-羟基和一个5‘-磷酰基。这种核酸内切活性需要Mg2+或Mn2+，并且对双链DNA具有高度的特异性。核酸内切酶V催化的含有脱氧黄嘌呤的DNA的切割是其识别改变的碱基的能力的结果，而不是由于其错配特异的内切酶活性所致。核酸内切酶V识别脱氧肌苷和脱氧黄嘌呤的能力表明，核酸内切酶V对于防止嘌呤脱氨基可能产生的突变是重要的。(C)2000 Elsevier Science B.V.保留所有权利。
Deoxycytidine, deoxyadenosine and deoxyguanosine undergo spontaneous deamination to form deoxyuridine, deoxyinosine and deoxyxanthosine, respectively. In this manuscript, we show that in addition to its known ability to recognize deoxyuridine and deoxyinosine in DNA, Escherichia coli endonuclease V cleaves DNA containing deoxyxanthosine. However, Alk A protein and human methylpurine glycosylase are unable to recognize deoxyxanthosine. Endonuclease V cleaves DNA containing deoxyxanthosine at the second phosphodiester bond 3' to deoxyxanthosine, generating a 3'-hydroxyl and a 5'-phosphoryl group at the nick site. This endonucleolytic activity requires Mg2+ or Mn2+, and is highly specific for double stranded DNA. Endonuclease V-catalyzed cleavage of DNA containing deoxyxanthosine is a result of its ability to recognize the altered base and not due to its mismatch-specific endonuclease activity. The ability of endonuclease V to recognize both deoxyinosine and deoxyxanthosine suggests that endonuclease V is important for preventing mutations that might arise as a result of deamination of purines. (C) 2000 Elsevier Science B.V. All rights reserved.