• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Nature >DNA synthesis provides the driving force to accelerate DNA unwinding by a helicase
【24h】

DNA synthesis provides the driving force to accelerate DNA unwinding by a helicase

机译：DNA合成提供了通过解旋酶加速DNA释放的驱动力

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

Helicases are molecular motors that use the energy of nucleoside 5'-triphosphate (NTP) hydrolysis to translocate along a nucleic acid strand and catalyse reactions such as DNA unwinding. The ring-shaped helicase(1) of bacteriophage T7 translocates along single-stranded ( ss) DNA at a speed of 130 bases per second(2); however, T7 helicase slows down nearly tenfold when unwinding the strands of duplex DNA(3). Here, we report that T7 DNA polymerase, which is unable to catalyse strand displacement DNA synthesis by itself, can increase the unwinding rate to 114 base pairs per second, bringing the helicase up to similar speeds compared to its translocation along ssDNA. The helicase rate of stimulation depends upon the DNA synthesis rate and does not rely on specific interactions between T7 DNA polymerase and the carboxy-terminal residues of T7 helicase. Efficient duplex DNA synthesis is achieved only by the combined action of the helicase and polymerase. The strand displacement DNA synthesis by the DNA polymerase depends on the unwinding activity of the helicase, which provides ssDNA template. The rapid trapping of the ssDNA bases by the DNA synthesis activity of the polymerase in turn drives the helicase to move forward through duplex DNA at speeds similar to those observed along ssDNA.
机译：解旋酶是利用核苷5'-三磷酸（NTP）水解的能量沿着核酸链转移并催化诸如DNA解链等反应的分子马达。噬菌体T7的环状解旋酶（1）沿单链（ss）DNA以每秒130个碱基的速度移位（2）；但是，解开双链DNA的链时，T7解旋酶的速度将降低近十倍（3）。在这里，我们报告说，T7 DNA聚合酶本身不能催化链置换DNA的合成，它可以将解旋速率提高到每秒114个碱基对，与解旋酶沿ssDNA的转运相比，其解链酶的速度达到了相似的水平。刺激的解旋酶速率取决于DNA合成速率，并且不依赖于T7 DNA聚合酶与T7解旋酶的羧基末端残基之间的特异性相互作用。仅通过解旋酶和聚合酶的联合作用才能实现有效的双链DNA合成。 DNA聚合酶的链置换DNA合成取决于解旋酶的解旋活性，解旋酶提供了ssDNA模板。聚合酶的DNA合成活性快速捕获ssDNA碱基，进而驱使解旋酶以与沿着ssDNA观察到的速度相似的速度向前穿过双链DNA。

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