• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Molecular and Cellular Biology >Base Pairing between U3 Small Nucleolar RNA and the 5′ End of 18S rRNA Is Required for Pre-rRNA Processing
【24h】

Base Pairing between U3 Small Nucleolar RNA and the 5′ End of 18S rRNA Is Required for Pre-rRNA Processing

机译：前rRNA加工需要U3小核仁RNA和18S rRNA的5'端之间的碱基配对

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The loop of a stem structure close to the 5′ end of the 18S rRNA is complementary to the box A region of the U3 small nucleolar RNA (snoRNA). Substitution of the 18S loop nucleotides inhibited pre-rRNA cleavage at site A1, the 5′ end of the 18S rRNA, and at site A2, located 1.9 kb away in internal transcribed spacer 1. This inhibition was largely suppressed by a compensatory mutation in U3, demonstrating functional base pairing. The U3–pre-rRNA base pairing is incompatible with the structure that forms in the mature 18S rRNA and may prevent premature folding of the pre-rRNA. In theEscherichia coli pre-rRNA the homologous region of the 16S rRNA is also sequestered, in that case by base pairing to the 5′ external transcribed spacer (5′ ETS). Cleavage at site A0in the yeast 5′ ETS strictly requires base pairing between U3 and a sequence within the 5′ ETS. In contrast, the U3-18S interaction is not required for A0 cleavage. U3 therefore carries out at least two functionally distinct base pair interactions with the pre-rRNA. The nucleotide at the site of A1 cleavage was shown to be specified by two distinct signals; one of these is the stem-loop structure within the 18S rRNA. However, in contrast to the efficiency of cleavage, the position of A1 cleavage is not dependent on the U3-loop interaction. We conclude that the 18S stem-loop structure is recognized at least twice during pre-rRNA processing.
机译：靠近18S rRNA 5'端的茎结构环与U3小核仁RNA（snoRNA）的box A区域互补。 18S环核苷酸的取代抑制pre-rRNA的切割在位点A 1 ，18S rRNA的5'端和位点A 2 （位于1.9 kb处）中。内部转录间隔区1.该抑制在很大程度上被U3中的补偿性突变所抑制，表明功能性碱基配对。 U3-pre-rRNA碱基配对与成熟的18S rRNA形成的结构不兼容，可能会阻止pre-rRNA的过早折叠。在大肠埃希氏菌前rRNA中，也将16S rRNA的同源区域隔离，在这种情况下，通过与5'外部转录间隔区（5'ETS）进行碱基配对。酵母5'ETS中位点A 0 的切割严格要求U3与5'ETS中的序列之间存在碱基配对。相反，A 0 裂解不需要U3-18S相互作用。因此，U3与前rRNA进行至少两个功能上不同的碱基对相互作用。结果表明，A 1 切割位点的核苷酸由两个不同的信号确定;其中之一是18S rRNA中的茎环结构。然而，与裂解效率相反，A 1 裂解的位置不依赖于U3-环的相互作用。我们得出的结论是，在pre-rRNA加工过程中至少两次识别18S茎环结构。

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