Characterization of a wide range base-damage-endonuclease activity of mammalian rpS3
Characterization of a wide range base-damage-endonuclease activity of mammalian rpS3
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DOI：
10.1016/j.bbrc.2005.01.045
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发表时间：
2005-03-25
影响因子：
3.1
通讯作者：
Kim, J
中科院分区：
文献类型：
--
作者：
Kim, SH;Lee, JY;Kim, J
哺乳动物rpS3是一种具有DNA修复内切酶活性的核糖体蛋白S3，可在强紫外线照射的DNA和含有AP位点的DNA上产生切口。RpS 3需要对T4嘧啶二聚体糖基化酶活性产生的嘧啶二聚体产生的AP位点进行新型内切核酸酶活性。这项研究表明，rpS3切割的病变，包括AP网站，胸腺嘧啶二醇，和其他UV损伤的病变，如嘧啶二聚体。该酶不具有如从其氨基酸序列预测的糖基化酶活性。然而，它对含有胸腺嘧啶乙二醇的DNA具有核酸内切酶活性，这与UV照射或AP DNA完全重叠，表明rpS3切割含有改变的碱基的DNA的磷酸二酯键，具有广泛的特异性，作为碱基损伤核酸内切酶。RpS3比松弛的RpS3更有效地切割超螺旋UV损伤的DNA，并且RpS3的内切酶活性被MgCl2抑制AP DNA，但不被UV照射的DNA。(C)2005年由Elsevier Inc.出版
Mammalian rpS3, a ribosomal protein S3 with a DNA repair endonuclease activity, nicks heavily UV-irradiated DNA and DNA containing AP sites. RpS3 calls for a novel endonucleolytic activity on AP sites generated from pyrimidine dimers by T4 pyrimidine dimer glycosylase activity. This study revealed that rpS3 cleaves the lesions including AP sites, thymine glycols, and other UV damaged lesions such as pyrimidine dimers. This enzyme does not have a glycosylase activity as predicted from its amino acid sequence. However, it has an endonuclease activity on DNA containing thymine glycol, which is exactly overlapped with UV-irradiated or AP DNAs, indicating that rpS3 cleaves phosphodiester bonds of DNAs containing altered bases with broad specificity acting as a base-damage-endonuclease. RpS3 cleaves supercoiled UV damaged DNA more efficiently than the relaxed counterpart, and the endonuclease activity of rpS3 was inhibited by MgCl2 on AP DNA but not on UV-irradiated DNA. (C) 2005 Published by Elsevier Inc.