The Drosophila ribosomal protein S3 contains a DNA deoxyribophosphodiesterase (dRpase) activity
The Drosophila ribosomal protein S3 contains a DNA deoxyribophosphodiesterase (dRpase) activity
复制标题
DOI：
10.1074/jbc.272.28.17480
复制
发表时间：
1997-07-11
影响因子：
4.8
通讯作者：
Franklin, WA
中科院分区：
文献类型：
--
作者：
Sandigursky, M;Yacoub, A;Franklin, WA
果蝇核糖体蛋白S3先前已被证明切割含有8-氧代鸟嘌呤残基的DNA，并且还被发现含有相关的脱嘌呤/脱嘧啶（AP）裂解酶活性，其通过β，δ-消除反应切割磷酸二酯键。该蛋白对含有切割AP位点的DNA底物的活性进行了检查。发现S3的谷胱甘肽S-转移酶融合蛋白能有效地从含有5 ′-切割AP位点的DNA底物以及含有3 ′-切割位点的DNA底物中除去糖-磷酸残基。通过β-消除反应从含有5 ′-切割的AP位点的底物中以4-羟基-2-戊烯醛-5-磷酸形式除去2-脱氧核糖-5-磷酸，如释放的糖-磷酸产物与巯基乙酸钠的反应所示。从含有3 ′-切割AP位点的底物上除去4-羟基-2-戊烯醛-5-磷酸酯的反应依赖于Mg ~（2+）阳离子的存在。这些研究结果表明，S3核糖体蛋白可能在真核生物中的DNA碱基切除修复途径的几个步骤中发挥作用，并可能代表氧化和电离辐射诱导的DNA损伤的修复的重要DNA修复功能。
The Drosophila ribosomal protein S3 has been previously demonstrated to cleave DNA containing 8-oxoguanine residues and has also been found to contain an associated apurinic/apyrimidinic (AP) lyase activity that cleaves phosphodiester bonds via a beta, delta-elimination reaction. The activity of this protein on DNA substrates containing incised AP sites was examined. A glutathione S-transferase fusion protein of S3 was found to efficiently remove sugar-phosphate residues from DNA substrates containing 5'-incised AP sites as well as from DNA substrates containing 3'-incised sites. Removal of 2-deoxyribose-5-phosphate as 4-hydroxy-2-pentenal-5-phosphate from a substrate containing 5'-incised AP sites occurred via a beta-elimination reaction, as indicated by reaction of the released sugar-phosphate products with sodium thioglycolate. The reaction for the removal of 4-hydroxy-2-pentenal-5-phosphate from the substrate containing 3'-incised AP sites was dependent oil the presence of the Mg2+ cation. These findings suggest that the S3 ribosomal protein may function in several steps of the DNA base excision repair pathway in eukaryotes and may represent an important DNA repair function for the repair of oxidative and ionizing radiation-induced DNA damage.