...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Proceedings of the National Academy of Sciences of the United States of America >Reverse transcriptase and endonuclease activities encoded by Penelope-like retroelements
【24h】

Reverse transcriptase and endonuclease activities encoded by Penelope-like retroelements

机译：佩内洛普样逆转录元件编码的逆转录酶和核酸内切酶活性

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Penelope-like elements are a class of retroelement that have now been identified in >50 species belonging to at least 10 animal phyla. The Penelope element isolated from Drosophila virilis is the only transpositionally active representative of this class isolated so far. The single ORF of Penelope and its relatives contains regions homologous to a reverse transcriptase of atypical structure and to the GIY-YIG, or Uri, an endonuclease (EN) domain not previously found in retroelements. We have expressed the single ORF of Penelope in a baculovirus expression system and have shown that it encodes a polyprotein with reverse transcriptase activity that requires divalent cations (Mn2+ and Mg2+). We have also expressed and purified the EN domain in Escherichia coli and have demonstrated that it has EN activity in vitro. Mutations in the conserved residues of the EN catalytic module abolish its nicking activity, whereas the DNA-binding properties of the mutant proteins remain unaffected. Only one strand of the target sequence is cleaved, and there is a certain degree of cleavage specificity. We propose that the Penelope EN cleaves the target DNA during transposition, generating a primer for reverse transcription. Our results show that an active Uri EN has been adopted by a retrotransposon.
机译：像佩内洛普一样的元素是一类逆行元素，现已在至少属于10个动物门的50多个物种中被发现。从果蝇中分离出的Penelope元素是迄今为止分离出的此类的唯一易位活性代表。佩内洛普及其亲属的单个ORF包含与非典型结构的逆转录酶和GIY-YIG或Uri（以前在反转录元件中未发现的内切核酸酶（EN）域）同源的区域。我们已经在杆状病毒表达系统中表达了佩内洛普的单个ORF，并表明它编码具有逆转录酶活性的多蛋白，该蛋白需要二价阳离子（Mn2 +和Mg2 +）。我们还在大肠杆菌中表达和纯化了EN结构域，并证明了它在体外具有EN活性。 EN催化模块的保守残基中的突变消除了其切刻活性，而突变蛋白的DNA结合特性则不受影响。仅切割靶序列的一条链，并且具有一定程度的切割特异性。我们建议，佩内洛普（Penelope）EN在转座过程中切割目标DNA，生成用于反转录的引物。我们的结果表明，逆转录转座子已采用了活跃的Uri EN。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号